Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivo...Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivotal to basic cellular processes.Close to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and localization.In this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in diseases.Furthermore,we have focused on N-acetyltransferase 9 and its role in microtubule stability.We have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative diseases.We have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration.展开更多
Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse ...Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.展开更多
Although great advances in elucidating the molecular basis and pathogenesis of Alzheimer’s disease(AD)have been made and multifarious novel therapeutic approaches have been developed,AD remains an incurable disease.E...Although great advances in elucidating the molecular basis and pathogenesis of Alzheimer’s disease(AD)have been made and multifarious novel therapeutic approaches have been developed,AD remains an incurable disease.Evidence shows that AD neuropathology occurs decades before clinical presentation.AD is divided into three stages:preclinical stage,mild cognitive impairment(MCI),and AD dementia.In the natural world,some animals,such as non-human primates(NHPs)and canines,can develop spontaneous AD-like dementia.However,most animals do not develop AD.With the development of transgenic techniques,both invertebrate and vertebrate animals have been employed to uncover the mechanisms of AD and study treatment methods.Most AD research focuses on early-onset familial AD(FAD)because FAD is associated with specific genetic mutations.However,there are no well-established late-onset sporadic AD(SAD)animal models because SAD is not directly linked to any genetic mutation,and multiple environmental factors are involved.Moreover,the widely used animal models are not able to sufficiently recapitulate the pathological events that occur in the MCI or preclinical stages.This review summarizes the common models used to study AD,from yeast to NHP models,and discusses the different applications,evaluation methods,and challenges related to AD animal models,as well as prospects for the evolution of future studies.展开更多
The most common age-related neurodegenerative disease is Alzheimer's disease(AD) characterized by aggregated amyloid-β(Aβ) peptides in extracellular plaques and aggregated hyperphosphorylated tau protein in intr...The most common age-related neurodegenerative disease is Alzheimer's disease(AD) characterized by aggregated amyloid-β(Aβ) peptides in extracellular plaques and aggregated hyperphosphorylated tau protein in intraneuronal neurofibrillary tangles,together with loss of cholinergic neurons,synaptic alterations,and chronic inflammation within the brain.These lead to progressive impairment of cognitive function.There is evidence of innate immune activation in AD with microgliosis.Classically-activated microglia(M1 state) secrete inflammatory and neurotoxic mediators,and peripheral immune cells are recruited to inflammation sites in the brain.The few drugs approved by the US FDA for the treatment of AD improve symptoms but do not change the course of disease progression and may cause some undesirable effects.Translation of active and passive immunotherapy targeting Aβ in AD animal model trials had limited success in clinical trials.Treatment with immunomodulatory/anti-inflammatory agents early in the disease process,while not preventive,is able to inhibit the inflammatory consequences of both Aβ and tau aggregation.The studies described in this review have identified several agents with immunomodulatory properties that alleviated AD pathology and cognitive impairment in animal models of AD.The majority of the animal studies reviewed had used transgenic models of early-onset AD.More effort needs to be given to creat models of late-onset AD.The effects of a combinational therapy involving two or more of the tested pharmaceutical agents,or one of these agents given in conjunction with one of the cell-based therapies,in an aged animal model of AD would warrant investigation.展开更多
Parkinson’s disease(PD) is an age-related neurodegenerative disease for which the characteristic motor symptoms emerge after an extensive loss of dopamine containing neurons.The cell bodies of these neurons are pre...Parkinson’s disease(PD) is an age-related neurodegenerative disease for which the characteristic motor symptoms emerge after an extensive loss of dopamine containing neurons.The cell bodies of these neurons are present in the substantia nigra,with the nerve terminals being in the striatum.Both innate and adaptive immune responses may contribute to dopaminergic neurodegeneration and disease progression is potentially linked to these.Studies in the last twenty years have indicated an important role for neuroinflammation in PD through degeneration of the nigrostriatal dopaminergic pathway.Characteristic of neuroinflammation is the activation of brain glial cells,principally microglia and astrocytes that release various soluble factors.Many of these factors are proinflammatory and neurotoxic and harmful to nigral dopaminergic neurons.Recent studies have identified several different agents with immunomodulatory properties that protected dopaminergic neurons from degeneration and death in animal models of PD.All of the agents were effective in reducing the motor deficit and alleviating dopaminergic neurotoxicity and,when measured,preventing the decrease of dopamine upon being administered therapeutically after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,6-hydroxydopamine,rotenone-lesioning or delivery of adeno-associated virus-α-synuclein to the ventral midbrain of animals.Some of these agents were shown to exert an anti-inflammatory action,decrease oxidative stress,and reduce lipid peroxidation products.Activation of microglia and astrocytes was also decreased,as well as infiltration of T cells into the substantia nigra.Pretreatment with fingolimod,tanshinoine I,dimethyl fumarate,thalidomide,or cocaine-and amphetamine-regulated transcript peptide as a preventive strategy ameliorated motor deficits and nigral dopaminergic neurotoxicity in brain-lesioned animals.Immunomodulatory agents could be used to treat patients with early clinical signs of the disease or potentially even prior to disease onset in those identified as having pre-disposing risk,including genetic factors.展开更多
A review of recent animal models of Huntington’s disease showed many microRNAs had altered expression levels in the striatum and cerebral cortex,and which were mostly downregulated.Among the altered microRNAs were mi...A review of recent animal models of Huntington’s disease showed many microRNAs had altered expression levels in the striatum and cerebral cortex,and which were mostly downregulated.Among the altered microRNAs were miR-9/9*,miR-29b,miR-124a,miR-132,miR-128,miR-139,miR-122,miR-138,miR-23b,miR-135b,miR-181(all downregulated)and miR-448(upregulated),and similar changes had been previously found in Huntington’s disease patients.In the animal cell studies,the altered microRNAs included miR-9,miR-9*,miR-135b,miR-222(all downregulated)and miR-214(upregulated).In the animal models,overexpression of miR-155 and miR-196a caused a decrease in mutant huntingtin mRNA and protein level,lowered the mutant huntingtin aggregates in striatum and cortex,and improved performance in behavioral tests.Improved performance in behavioral tests also occurred with overexpression of miR-132 and miR-124.In the animal cell models,overexpression of miR-22 increased the viability of rat primary cortical and striatal neurons infected with mutant huntingtin and decreased huntingtin-enriched foci of≥2μm.Also,overexpression of miR-22 enhanced the survival of rat primary striatal neurons treated with 3-nitropropionic acid.Exogenous expression of miR-214,miR-146a,miR-150,and miR-125b decreased endogenous expression of huntingtin mRNA and protein in HdhQ111/HdhQ111 cells.Further studies with animal models of Huntington’s disease are warranted to validate these findings and identify specific microRNAs whose overexpression inhibits the production of mutant huntingtin protein and other harmful processes and may provide a more effective means of treating Huntington’s disease in patients and slowing its progression.展开更多
Parkinson’s disease is typically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta.Many studies have been performed based on the supplementation of lost dopaminergic ...Parkinson’s disease is typically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta.Many studies have been performed based on the supplementation of lost dopaminergic neurons to treat Parkinson’s disease.The initial strategy for cell replacement therapy used human fetal ventral midbrain and human embryonic stem cells to treat Parkinson’s disease,which could substantially alleviate the symptoms of Parkinson’s disease in clinical practice.However,ethical issues and tumor formation were limitations of its clinical application.Induced pluripotent stem cells can be acquired without sacrificing human embryos,which eliminates the huge ethical barriers of human stem cell therapy.Another widely considered neuronal regeneration strategy is to directly reprogram fibroblasts and astrocytes into neurons,without the need for intermediate proliferation states,thus avoiding issues of immune rejection and tumor formation.Both induced pluripotent stem cells and direct reprogramming of lineage cells have shown promising results in the treatment of Parkinson’s disease.However,there are also ethical concerns and the risk of tumor formation that need to be addressed.This review highlights the current application status of cell reprogramming in the treatment of Parkinson’s disease,focusing on the use of induced pluripotent stem cells in cell replacement therapy,including preclinical animal models and progress in clinical research.The review also discusses the advancements in direct reprogramming of lineage cells in the treatment of Parkinson’s disease,as well as the controversy surrounding in vivo reprogramming.These findings suggest that cell reprogramming may hold great promise as a potential strategy for treating Parkinson’s disease.展开更多
Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation...Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment.展开更多
AIM: To explore the relevance of Maotai liquor and liver diseases. METHODS: Epidemiological study was conducted on groups of subjects, each consisting of 3 subjects from the Maotai liquor group consisting of 99 indivi...AIM: To explore the relevance of Maotai liquor and liver diseases. METHODS: Epidemiological study was conducted on groups of subjects, each consisting of 3 subjects from the Maotai liquor group consisting of 99 individuals and one from the non-alcoholic control group consisting of 33 individuals. Liver biopsy was performed on 23 volunteers from Guizhou Maotai Distillery who had a constant and long history of drinking Maotai liquor. Experimental histopathological study was conducted as follows: sixty male Wistar rats were divided into 3 groups randomly and fed with Maotai liquor, ordinary white wine, and physiological saline respectively for a period of 8 and 12 weeks. The rats were sacrificed in batches, then serum ALT, AST, TBil, and AKP were measured. Rat livers were harvested to measure the liver indexes, GSH, and MDA. Histopathological examinations were also performed. Another eighty mice were randomly divided into 4 groups and fed with Maotai (at different dosages of 10 ml.kg(-1) and 20 ml.kg(-1)), ethanol, and physiological saline. The animals were sacrificed after 4 weeks and serum ALT was determined. Then the livers were harvested and liver indexes and MDA were measured. RESULTS: The incidence rate of hepatic symptoms, splenomegaly, liver function impairment, reversal of Albumin/Globulin and increased diameter of portal veins in the Maotai liquor group were 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 0 0/99 and 0 0/99 , 0 0/99 ,0 0/99 , 0 0/99 , 0 0/99 , respectively. There was no significant difference between the Maotai group and the non-alcoholic control group P】0.05 . Various degree of fatty infiltration of hepatocytes was found in the 23 volunteers receiving liver biopsy, but there was no obvious hepatic fibrosis or cirrhosis. A comparison was made between the Maotai liquor group and the ordinary white wine group. It was found that hepatic MDA in rats and mice were 0.33+/-0.10 and 0.49+/-0.23 respectively in Maotai group and 0.61+/-0.22 and 0.66+/-0.32 in the ordinary white wine group; MDA had an obvious decrease in the Maotai liquor group (P【0.05); hepatic GSH were 0.12 mg.g(-1)+/-0.06 mg.g(-1) in rats of the Maotai liquor group and (0.08+/-0.02)mg.g(-1) in white wine group, it was obviously increased in the Maotai liquor group (P【0.05). After the 20 rats had been fed with ordinary white wine for 8 weeks consecutively, disarranged hepatocyte cords, fatty infiltration of hepatocytes, and fibrous septa of varying widths due to hepatic connective tissues proliferation were observed; after 12 weeks, the fibrous tissue proliferation continued and early cirrhosis appeared. Compared with the ordinary white wine group, fatty infiltration was observed in the 8-week and 12-week groups, but no necrosis or fibrosis or cirrhosis was found in the Maotai liquor group (P【0.05). CONCLUSION: Maotai liquor may cause fatty liver but not hepatic fibrosis or cirrhosis, and it can strengthen lipid peroxidation in the liver.展开更多
Extensive iron deposition has been observed in the midbrain substantia nigra (SN) of Parkinson's disease (PD) patients, but the mechanisms of iron deposition in the SN remain poorly understood. The present study ...Extensive iron deposition has been observed in the midbrain substantia nigra (SN) of Parkinson's disease (PD) patients, but the mechanisms of iron deposition in the SN remain poorly understood. The present study investigated the relationship between dopaminergic neuronal damage, iron content changes, and divalent metal transporter 1 (DMT1) in the midbrain SN of PD rats to explore the relationship between time of iron deposition and DMT1 expression. Frozen midbrain SN sections from model rats were stained with Perls' iron. Results showed massive loss of tyrosine hydroxylase (TH)-positive cells in the SN and increased DMT1 expression in model group rats. No obvious iron deposition was observed in the SN during early stages after damage, but significant iron deposition was detected at 8 weeks post-injury. Results demonstrate that the loss of TH-positive cells in the SN appeared simultaneously with increased DMT1 expression. Extensive iron deposition occurred at 8 weeks post injury, which could be regarded as an early time window of iron deposition.展开更多
Parkinson's disease(PD) is the second most common age-related neurodegenerative disorder, with the clinical main symptoms caused by a loss of dopaminergic neurons in the substantia nigra, corpus striatum and brain ...Parkinson's disease(PD) is the second most common age-related neurodegenerative disorder, with the clinical main symptoms caused by a loss of dopaminergic neurons in the substantia nigra, corpus striatum and brain cortex. Over 90% of patients with PD have sporadic PD and occur in people with no known family history of the disorder. Currently there is no cure for PD. Treatment with medications to increase dopamine relieves the symptoms but does not slow down or reverse the damage to neurons in the brain. Increasing evidence points to inflammation as a chief mediator of PD with inflammatory response mechanisms, involving microglia and leukocytes, activated following loss of dopaminergic neurons. Oxidative stress is also recognized as one of the main causes of PD, and excessive reactive oxygen species(ROS) and reactive nitrogen species can lead to dopaminergic neuron vulnerability and eventual death. Micro RNAs control a range of physiological and pathological functions, and may serve as potential targets for intervention against PD to mitigate damage to the brain. Several studies have demonstrated that micro RNAs can regulate oxidative stress and prevent ROS-mediated damage to dopaminergic neurons, suggesting that specific micro RNAs may be putative targets for novel therapeutic strategies in PD. Recent human and animal studies have identified a large number of dysregulated micro RNAs in PD brain tissue samples, many of which were downregulated. The dysregulated micro RNAs affect downstream targets such as SNCA, PARK2, LRRK2, TNFSF13 B, LTA, SLC5 A3, PSMB2, GSR, GBA, LAMP-2 A, HSC. Apart from one study, none of the studies reviewed had used agomirs or antagomirs to reverse the levels of downregulated or upregulated micro RNAs, respectively, in mouse models of PD or with isolated human or mouse dopaminergic cells. Further large-scale studies of brain tissue samples collected with short postmortem interval from human PD patients are warranted to provide more information on the micro RNA profiles in different brain regions and to test for gender differences.展开更多
Alzheimer's disease(AD), a fatal progressive neurodegenerative disorder, has no cure to date. One of the causes of AD is the accumulation of amyloid-beta 42(Aβ42) plaques, which result in the onset of neurodegen...Alzheimer's disease(AD), a fatal progressive neurodegenerative disorder, has no cure to date. One of the causes of AD is the accumulation of amyloid-beta 42(Aβ42) plaques, which result in the onset of neurodegeneration. It is not known how these plaques trigger the onset of neurodegeneration. There are several animal models developed to(i) study etiology of disease,(ii) look for genetic modifiers, and(iii) identify chemical inhibitors that can block neurodegeneration and help to find cure for this disease. An insect model of Drosophila melanogaster has also provided new insights into the disease. Here we will discuss the utility of the Drosophila eye model to study Alzheimer's disease.展开更多
Given the failure to develop disease-modifying therapies for Alzheimer’s disease(AD),strategies aiming at preventing or delaying the onset of the disease are being prioritized.While the debate regarding whether depre...Given the failure to develop disease-modifying therapies for Alzheimer’s disease(AD),strategies aiming at preventing or delaying the onset of the disease are being prioritized.While the debate regarding whether depression is an etiological risk factor or a prodrome of AD rages on,a key determining factor may be the timing of depression onset in older adults.There is increasing evidence that untreated early-onset depression is a risk factor and that late-onset depression may be a catalyst of cognitive decline.Data from animal studies have shown a beneficial impact of selective serotonin reuptake inhibitors on pathophysiological biomarkers of AD including amyloid burden,tau deposits and neurogenesis.In humans,studies focusing on subjects with a prior history of depression also showed a delay in the onset of AD in those treated with most selective serotonin reuptake inhibitors.Paroxetine,which has strong anticholinergic properties,was associated with increased mortality and mixed effects on amyloid and tau deposits in mice,as well as increased odds of developing AD in humans.Although most of the data regarding selective serotonin reuptake inhibitors is promising,findings should be interpreted cautiously because of notable methodological heterogeneity between studies.There is thus a need to conduct large scale randomized controlled trials with long follow up periods to clarify the dose-effect relationship of specific serotonergic antidepressants on AD prevention.展开更多
BACKGROUND: Modem pharmacological studies have demonstrated that Panax notoginseng saponins (PNS) can ameliorate and protect from neuropathological impairment. Whether PNS can improve the abnormality in memory and ...BACKGROUND: Modem pharmacological studies have demonstrated that Panax notoginseng saponins (PNS) can ameliorate and protect from neuropathological impairment. Whether PNS can improve the abnormality in memory and behavior of rats with Alzheimer's disease (AD) remains unclear. OBJECTIVE: Based on a Morris water maze test, this study aimed to measure improvements of spatial learning and memory by PNS in a rat model of AD, and to compare effects with huperzine A. DESIGN: A completely randomized grouping design, controlled animal experiment. SETTING: Center of Research & Development of New Drugs, Guangxi Traditional Chinese Medical University. MATERIALS: Ninety healthy Wistar rats of both genders, 15-month-old (n =75) and 3-month-old rats as young controls (n =15), were used for this study. The study was performed in accordance with animal ethics guidelines for the use and care of animals. PNS was provided by Weihe Pharmaceutical Co., Ltd (permission No. Z53021485, Yuxi, Yunan Province, China). Morris water maze equipment was provided by the Institute of Physiology, Chinese Academy of Science. METHODS: This study was performed at the Center of Research & Development of New Drugs, Guangxi Traditional Chinese Medical University from June 2003 to April 2005. Of the included rats, 15 healthy aged rats were randomly chosen as aged controls, and the remaining 60 aged rats were randomly divided into 4 groups with 15 rats in each: model group, PNS high- and low-dose groups, and an huperzine A group. Rats in the model group and the 3 treated groups were treated with intraperitoneal infusion of 9.6 g/L D-galactose (5 mL/kg) every day for 6 weeks successively to induce a subacute aging model. During week 7, animals received 1 μ L ibotenic acid (5 g/L) bilaterally into the nucleus basalis of Meynert to create a rat model of AD. The young and old rat controls received, in parallel, a corresponding volume of saline. Two weeks later, rats in the PNS high- and low-dose groups were gavaged with 200 and 100 mg/kg PNS suspension, respectively. Huperzine A suspension (0.3 mg/kg) was used in the huperzine A group. Rats in the other 3 groups were gavaged with a corresponding volume of normal saline. In each group, administration was carried out once per day for 4 consecutive weeks. MAIN OUTCOME MEASURES: After administration, learning and memory abilities were measured by place navigation and spatial probe tests. Recording indices consisted of escape latency (time-to-platform), number of times to find the platform within 2 minutes, number of times the animal crosses the original platform location, and the percent of swimming time in each quadrant. RESULTS: Several rats died due to inflammatory reactions following brain lesion or intragastric administration; therefore, 61 rats were included in the final analysis. Results of spatial navigation test: Escape latency of rats in the model group was significantly prolonged, and number of times to find the platform within 2 minutes were significantly reduced compared with other groups (both P 〈 0.05). No significant differences in these two indices were measured among the administration groups (all P 〉 0.05). Results of spatial probe test: Times for crossing the original platform location and percent of time spent in the quadrant of original platform location were significantly less in the model group than in the other groups (P 〈 0.05). There were no significant differences in these two indices among the administration groups (P 〉 0.05). CONCLUSION: PNS can remarkably improve spatial learning and memory abilities of rats with AD. The therapeutic effect of PNS is not dose-dependent and is equivalent to the effect of huperzine A.展开更多
Adult neurogenesis is the creation of new neurons which integrate into the existing neural circuit of the adult brain.Recent evidence suggests that adult hippocampal neurogenesis(AHN)persists throughout life in mammal...Adult neurogenesis is the creation of new neurons which integrate into the existing neural circuit of the adult brain.Recent evidence suggests that adult hippocampal neurogenesis(AHN)persists throughout life in mammals,including humans.These newborn neurons have been implicated to have a crucial role in brain functions such as learning and memory.Importantly,studies have also found that hippocampal neurogenesis is impaired in neurodegenerative and neuropsychiatric diseases.Alzheimer’s disease(AD)is one of the most common forms of dementia affecting millions of people.Cognitive dysfunction is a common symptom of AD patients and progressive memory loss has been attributed to the degeneration of the hippocampus.Therefore,there has been growing interest in identifying how hippocampal neurogenesis is affected in AD.However,the link between cognitive decline and changes in hippocampal neurogenesis in AD is poorly understood.In this review,we summarized the recent literature on AHN and its impairments in AD.展开更多
For decades,clinicians have developed medications and therapies to alleviate the symptoms of Parkinson’s disease,but no treatment currently can slow or even stop the progression of this localized neurodegeneration.Fo...For decades,clinicians have developed medications and therapies to alleviate the symptoms of Parkinson’s disease,but no treatment currently can slow or even stop the progression of this localized neurodegeneration.Fortunately,sparked by the genetic revolution,stem cell reprogramming research and the advancing capabilities of personalization in medicine enable forward-thinking to unprecedented patient-specific modeling and cell therapies for Parkinson’s disease using induced pluripotent stem cells(iPSCs).In addition to modeling Parkinson’s disease more accurately than chemically-induced animal models,patient-specific stem cell lines can be created,elucidating the effects of genetic susceptibility and sub-populations’differing responses to in vitro treatments.Sourcing cell therapy with iPSC lines provides ethical advantages because these stem cell lines do not require the sacrifice of human zygotes and genetically-specific drug trails can be tested in vitro without lasting damage to patients.In hopes of finally slowing the progression of Parkinson’s disease or re-establishing function,iPSC lines can ultimately be corrected with gene therapy and used as cell sources for neural transplantation for Parkinson’s disease.With relatively localized neural degeneration,similar to spinal column injury,Parkinson’s disease presents a better candidacy for cell therapy when compared to other diffuse degeneration found in Alzheimer’s or Huntington’s Disease.Neurosurgical implantation of pluripotent cells poses the risk of an innate immune response and tumorigenesis.Precautions,therefore,must be taken to ensure cell line quality before transplantation.While cell quality can be quantified using a number of assays,a yielding a high percentage of therapeutically relevant dopaminergic neurons,minimal de novo genetic mutations,and standard chromosomal structure is of the utmost importance.Current techniques focus on iPSCs because they can be matched with donors using human leukocyte antigens,thereby reducing the severity and risk of immune rejection.In August of 2018,researchers in Kyoto,Japan embarked on the first human clinical trial using iPSC cell therapy transplantation for patients with moderate Parkinson’s disease.Transplantation of many cell sources has already proven to reduce Parkinson’s disease symptoms in mouse and primate models.Here we discuss the history and implications for cell therapy for Parkinson’s disease,as well as the necessary safety standards needed for using iPSC transplantation to slow or halt the progression of Parkinson’s disease.展开更多
The pathophysiology of LaPeyronie's disease (PD) is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been valida...The pathophysiology of LaPeyronie's disease (PD) is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been validated using animal models. In this study, we have presented a new model obtained by tunica albuginea allograft. A total of 40, 16-week-old male rats were used. Of these, 8 rats served as controls and underwent a 10 × 2-mm-wide tunical excisionwith subsequent autografting, whereas the remaining 32 underwent the same excision with grafting of the defect with another rat's tunica. Morphological and functional testing was performed at 1, 3, 7 and 12 weeks after grafting. Intracavernous pressure, the degree of penile curvature and elastic fiber length were evaluated for comparison between the allograft and control groups. The tissues were obtained for histological examination. The penile curvature was significantly greater in the allografted rats as compared with the control rats. The erectile function was maintained in all rats, except in those assessed at 12 weeks. The elastin fiber length was decreased in the allografted tunica as compared to control. SMAD2 expression was detected in the inner part of the allograff, and both collagen-Ⅱ- and osteocalcin-positive cells were also noted. Tunica albuginea (TA) allograft in rats is an excellent model of PD. The persistence of curvature beyond 12 weeks and the presence of ossification in the inner layer of the TA were similar to those observed in men with PD. Validation studies using this animal model would aid understanding of the PD pathophysiology for effective therapeutic interventions.展开更多
AIM: To evaluate the relationship between the expression of lipopolysaccharides (LPS) binding protein (LBP) and CD14 mRNA and the severity of liver injury in alcohol-fed rats. METHODS: Twenty Wistar rats were divided ...AIM: To evaluate the relationship between the expression of lipopolysaccharides (LPS) binding protein (LBP) and CD14 mRNA and the severity of liver injury in alcohol-fed rats. METHODS: Twenty Wistar rats were divided into two groups:ethanol-fed group (group E) and control group (group C). Group E was fed with ethanol(5-12 g x kg(-1) x d(-1)) and group C received dextrose instead of ethanol. Rats of the two groups were sacrificed at 4 weeks and 8 weeks. Levels of endotoxin and alanine transaminase (ALT) in blood were measured, and liver pathology was observed under light and electronic microscopy. Expressions of LBP and CD14 mRNA in liver tissues were determined by RT-PCR analysis. RESULTS: Plasma endotoxin levels were increased more significantly in group E(129+/-21) ng x L(-1) and (187+/-35) ng x L(-1) at 4 and 8 wk than in control rats(48+/-9) ng x L(-1) and (53+/-11) ng x L(-1), respectively (P【0.05). Mean values of plasma ALT levels were (1867+/-250) nkat x L(-1) and (2450+/-367) nkat x L(-1) in Group E. The values were increased more dramatically in ethanol-fed rats than in Group C after 4 and 8 weeks. In liver section from ethanol-fed rats, there were marked pathological changes (steatosis, cell infiltration and necrosis). In ethanol-fed rats, ethanol administration led to a significant increase in LBP and CD14 mRNA levels compared with the control group (P【0.05). CONCLUSION: Ethanol administration led to a significant increase in endotoxin levels in serum and LBP and CD14 mRNA expressions in liver tissues. The increase of LBP and CD14 mRNA expression might wake the liver more sensitive to endotoxin and liver injury.展开更多
MOLECULAR PHYSIOLLGY OF HEPATOCELLULAR TRANSPORT PROTEINS Basolaferal transport systems Na+-dependent bile salt uptake Uptake of bile salts into the liver was first isolated perfused rat liver[1],isolated hepatocyte...MOLECULAR PHYSIOLLGY OF HEPATOCELLULAR TRANSPORT PROTEINS Basolaferal transport systems Na+-dependent bile salt uptake Uptake of bile salts into the liver was first isolated perfused rat liver[1],isolated hepatocyte cultures and basolateral plasma membrane vesicles [2,4].展开更多
Cell grafting has been considered a therapeutic approach for Parkinson's disease(PD) since the 1980 s. The classical motor symptoms of PD are caused by the loss of dopaminergic neurons in the substantia nigra pars...Cell grafting has been considered a therapeutic approach for Parkinson's disease(PD) since the 1980 s. The classical motor symptoms of PD are caused by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to a decrement in dopamine release in the striatum. Consequently, the therapy of celltransplantation for PD consists in grafting dopamineproducing cells directly into the brain to reestablish dopamine levels. Different cell sources have been shown to induce functional benefits on both animal models of PD and human patients. However, the observed motor improvements are highly variable between individual subjects, and the sources of this variability are not fully understood. The purpose of this review is to provide a general overview of the pioneering studies done in animal models of PD that established the basis for the first clinical trials in humans, and compare these with the latest findings to identify the most relevant aspects that remain unanswered to date. The main focus of the discussions presented here will be on the mechanisms associated with the survival and functionality of the transplants. These include the role of the dopamine released by the grafts and the capacity of the grafted cells to extend fibers and to integrate into the motor circuit. The complete understanding of these aspects will require extensive research on basic aspects of molecular and cellular physiology, together with neuronal network function, in order to uncover the real potential of cell grafting for treating PD.展开更多
基金supported by 1RO1EY032959-01 and RO1 supplement from NIH,Schuellein Chair Endowment Fund and STEM Catalyst Grant from the University of Dayton(to AS).
文摘Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivotal to basic cellular processes.Close to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and localization.In this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in diseases.Furthermore,we have focused on N-acetyltransferase 9 and its role in microtubule stability.We have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative diseases.We have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration.
文摘Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols.
基金supported by the National Science and Technology Innovation 2030-Major Program of“Brain Science and Brain-Like Research”(2022ZD0211800)National Natural Science Foundation of China(NSFC)General Research Grants(81971679,32020103007,32088101,21727806)+1 种基金Ministry of Science and Technology(2018YFA0507600,2017YFA0503600)Qidong-PKU SLS Innovation Fund(2016000663,2017000246)。
文摘Although great advances in elucidating the molecular basis and pathogenesis of Alzheimer’s disease(AD)have been made and multifarious novel therapeutic approaches have been developed,AD remains an incurable disease.Evidence shows that AD neuropathology occurs decades before clinical presentation.AD is divided into three stages:preclinical stage,mild cognitive impairment(MCI),and AD dementia.In the natural world,some animals,such as non-human primates(NHPs)and canines,can develop spontaneous AD-like dementia.However,most animals do not develop AD.With the development of transgenic techniques,both invertebrate and vertebrate animals have been employed to uncover the mechanisms of AD and study treatment methods.Most AD research focuses on early-onset familial AD(FAD)because FAD is associated with specific genetic mutations.However,there are no well-established late-onset sporadic AD(SAD)animal models because SAD is not directly linked to any genetic mutation,and multiple environmental factors are involved.Moreover,the widely used animal models are not able to sufficiently recapitulate the pathological events that occur in the MCI or preclinical stages.This review summarizes the common models used to study AD,from yeast to NHP models,and discusses the different applications,evaluation methods,and challenges related to AD animal models,as well as prospects for the evolution of future studies.
文摘The most common age-related neurodegenerative disease is Alzheimer's disease(AD) characterized by aggregated amyloid-β(Aβ) peptides in extracellular plaques and aggregated hyperphosphorylated tau protein in intraneuronal neurofibrillary tangles,together with loss of cholinergic neurons,synaptic alterations,and chronic inflammation within the brain.These lead to progressive impairment of cognitive function.There is evidence of innate immune activation in AD with microgliosis.Classically-activated microglia(M1 state) secrete inflammatory and neurotoxic mediators,and peripheral immune cells are recruited to inflammation sites in the brain.The few drugs approved by the US FDA for the treatment of AD improve symptoms but do not change the course of disease progression and may cause some undesirable effects.Translation of active and passive immunotherapy targeting Aβ in AD animal model trials had limited success in clinical trials.Treatment with immunomodulatory/anti-inflammatory agents early in the disease process,while not preventive,is able to inhibit the inflammatory consequences of both Aβ and tau aggregation.The studies described in this review have identified several agents with immunomodulatory properties that alleviated AD pathology and cognitive impairment in animal models of AD.The majority of the animal studies reviewed had used transgenic models of early-onset AD.More effort needs to be given to creat models of late-onset AD.The effects of a combinational therapy involving two or more of the tested pharmaceutical agents,or one of these agents given in conjunction with one of the cell-based therapies,in an aged animal model of AD would warrant investigation.
文摘Parkinson’s disease(PD) is an age-related neurodegenerative disease for which the characteristic motor symptoms emerge after an extensive loss of dopamine containing neurons.The cell bodies of these neurons are present in the substantia nigra,with the nerve terminals being in the striatum.Both innate and adaptive immune responses may contribute to dopaminergic neurodegeneration and disease progression is potentially linked to these.Studies in the last twenty years have indicated an important role for neuroinflammation in PD through degeneration of the nigrostriatal dopaminergic pathway.Characteristic of neuroinflammation is the activation of brain glial cells,principally microglia and astrocytes that release various soluble factors.Many of these factors are proinflammatory and neurotoxic and harmful to nigral dopaminergic neurons.Recent studies have identified several different agents with immunomodulatory properties that protected dopaminergic neurons from degeneration and death in animal models of PD.All of the agents were effective in reducing the motor deficit and alleviating dopaminergic neurotoxicity and,when measured,preventing the decrease of dopamine upon being administered therapeutically after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine,6-hydroxydopamine,rotenone-lesioning or delivery of adeno-associated virus-α-synuclein to the ventral midbrain of animals.Some of these agents were shown to exert an anti-inflammatory action,decrease oxidative stress,and reduce lipid peroxidation products.Activation of microglia and astrocytes was also decreased,as well as infiltration of T cells into the substantia nigra.Pretreatment with fingolimod,tanshinoine I,dimethyl fumarate,thalidomide,or cocaine-and amphetamine-regulated transcript peptide as a preventive strategy ameliorated motor deficits and nigral dopaminergic neurotoxicity in brain-lesioned animals.Immunomodulatory agents could be used to treat patients with early clinical signs of the disease or potentially even prior to disease onset in those identified as having pre-disposing risk,including genetic factors.
文摘A review of recent animal models of Huntington’s disease showed many microRNAs had altered expression levels in the striatum and cerebral cortex,and which were mostly downregulated.Among the altered microRNAs were miR-9/9*,miR-29b,miR-124a,miR-132,miR-128,miR-139,miR-122,miR-138,miR-23b,miR-135b,miR-181(all downregulated)and miR-448(upregulated),and similar changes had been previously found in Huntington’s disease patients.In the animal cell studies,the altered microRNAs included miR-9,miR-9*,miR-135b,miR-222(all downregulated)and miR-214(upregulated).In the animal models,overexpression of miR-155 and miR-196a caused a decrease in mutant huntingtin mRNA and protein level,lowered the mutant huntingtin aggregates in striatum and cortex,and improved performance in behavioral tests.Improved performance in behavioral tests also occurred with overexpression of miR-132 and miR-124.In the animal cell models,overexpression of miR-22 increased the viability of rat primary cortical and striatal neurons infected with mutant huntingtin and decreased huntingtin-enriched foci of≥2μm.Also,overexpression of miR-22 enhanced the survival of rat primary striatal neurons treated with 3-nitropropionic acid.Exogenous expression of miR-214,miR-146a,miR-150,and miR-125b decreased endogenous expression of huntingtin mRNA and protein in HdhQ111/HdhQ111 cells.Further studies with animal models of Huntington’s disease are warranted to validate these findings and identify specific microRNAs whose overexpression inhibits the production of mutant huntingtin protein and other harmful processes and may provide a more effective means of treating Huntington’s disease in patients and slowing its progression.
基金supported by the National Natural Science Foundation of China,No.31960120Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(both to ZW).
文摘Parkinson’s disease is typically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta.Many studies have been performed based on the supplementation of lost dopaminergic neurons to treat Parkinson’s disease.The initial strategy for cell replacement therapy used human fetal ventral midbrain and human embryonic stem cells to treat Parkinson’s disease,which could substantially alleviate the symptoms of Parkinson’s disease in clinical practice.However,ethical issues and tumor formation were limitations of its clinical application.Induced pluripotent stem cells can be acquired without sacrificing human embryos,which eliminates the huge ethical barriers of human stem cell therapy.Another widely considered neuronal regeneration strategy is to directly reprogram fibroblasts and astrocytes into neurons,without the need for intermediate proliferation states,thus avoiding issues of immune rejection and tumor formation.Both induced pluripotent stem cells and direct reprogramming of lineage cells have shown promising results in the treatment of Parkinson’s disease.However,there are also ethical concerns and the risk of tumor formation that need to be addressed.This review highlights the current application status of cell reprogramming in the treatment of Parkinson’s disease,focusing on the use of induced pluripotent stem cells in cell replacement therapy,including preclinical animal models and progress in clinical research.The review also discusses the advancements in direct reprogramming of lineage cells in the treatment of Parkinson’s disease,as well as the controversy surrounding in vivo reprogramming.These findings suggest that cell reprogramming may hold great promise as a potential strategy for treating Parkinson’s disease.
基金National Key R&D Program of China(2023YFB3507004)National Natural Science Foundation of China(U21A20148)+2 种基金International Partnership Program of Chinese Academy of Sciences(116134KYSB20210052)Heye Health Technology Chong Ming Project(HYCMP2021010)CASHIPS Director’s Fund(BJPY2021A06)。
文摘Amyloid beta(Aβ)monomers aggregate to form fibrils and amyloid plaques,which are critical mechanisms in the pathogenesis of Alzheimer’s disease(AD).Given the important role of Aβ1-42 aggregation in plaque formation,leading to brain lesions and cognitive impairment,numerous studies have aimed to reduce Aβaggregation and slow AD progression.The diphenylalanine(FF)sequence is critical for amyloid aggregation,and magnetic fields can affect peptide alignment due to the diamagnetic anisotropy of aromatic rings.In this study,we examined the effects of a moderate-intensity rotating magnetic field(RMF)on Aβaggregation and AD pathogenesis.Results indicated that the RMF directly inhibited Aβamyloid fibril formation and reduced Aβ-induced cytotoxicity in neural cells in vitro.Using the AD mouse model APP/PS1,RMF restored motor abilities to healthy control levels and significantly alleviated cognitive impairments,including exploration and spatial and non-spatial memory abilities.Tissue examinations demonstrated that RMF reduced amyloid plaque accumulation,attenuated microglial activation,and reduced oxidative stress in the APP/PS1 mouse brain.These findings suggest that RMF holds considerable potential as a non-invasive,high-penetration physical approach for AD treatment.
基金The primary sciences and technology project of Guizhou province,No.19992015
文摘AIM: To explore the relevance of Maotai liquor and liver diseases. METHODS: Epidemiological study was conducted on groups of subjects, each consisting of 3 subjects from the Maotai liquor group consisting of 99 individuals and one from the non-alcoholic control group consisting of 33 individuals. Liver biopsy was performed on 23 volunteers from Guizhou Maotai Distillery who had a constant and long history of drinking Maotai liquor. Experimental histopathological study was conducted as follows: sixty male Wistar rats were divided into 3 groups randomly and fed with Maotai liquor, ordinary white wine, and physiological saline respectively for a period of 8 and 12 weeks. The rats were sacrificed in batches, then serum ALT, AST, TBil, and AKP were measured. Rat livers were harvested to measure the liver indexes, GSH, and MDA. Histopathological examinations were also performed. Another eighty mice were randomly divided into 4 groups and fed with Maotai (at different dosages of 10 ml.kg(-1) and 20 ml.kg(-1)), ethanol, and physiological saline. The animals were sacrificed after 4 weeks and serum ALT was determined. Then the livers were harvested and liver indexes and MDA were measured. RESULTS: The incidence rate of hepatic symptoms, splenomegaly, liver function impairment, reversal of Albumin/Globulin and increased diameter of portal veins in the Maotai liquor group were 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 1.0% 1/99 , 0 0/99 and 0 0/99 , 0 0/99 ,0 0/99 , 0 0/99 , 0 0/99 , respectively. There was no significant difference between the Maotai group and the non-alcoholic control group P】0.05 . Various degree of fatty infiltration of hepatocytes was found in the 23 volunteers receiving liver biopsy, but there was no obvious hepatic fibrosis or cirrhosis. A comparison was made between the Maotai liquor group and the ordinary white wine group. It was found that hepatic MDA in rats and mice were 0.33+/-0.10 and 0.49+/-0.23 respectively in Maotai group and 0.61+/-0.22 and 0.66+/-0.32 in the ordinary white wine group; MDA had an obvious decrease in the Maotai liquor group (P【0.05); hepatic GSH were 0.12 mg.g(-1)+/-0.06 mg.g(-1) in rats of the Maotai liquor group and (0.08+/-0.02)mg.g(-1) in white wine group, it was obviously increased in the Maotai liquor group (P【0.05). After the 20 rats had been fed with ordinary white wine for 8 weeks consecutively, disarranged hepatocyte cords, fatty infiltration of hepatocytes, and fibrous septa of varying widths due to hepatic connective tissues proliferation were observed; after 12 weeks, the fibrous tissue proliferation continued and early cirrhosis appeared. Compared with the ordinary white wine group, fatty infiltration was observed in the 8-week and 12-week groups, but no necrosis or fibrosis or cirrhosis was found in the Maotai liquor group (P【0.05). CONCLUSION: Maotai liquor may cause fatty liver but not hepatic fibrosis or cirrhosis, and it can strengthen lipid peroxidation in the liver.
基金the Scientific Research Common Program of Beijing Municipal Commission of Education,No.KM200610025008
文摘Extensive iron deposition has been observed in the midbrain substantia nigra (SN) of Parkinson's disease (PD) patients, but the mechanisms of iron deposition in the SN remain poorly understood. The present study investigated the relationship between dopaminergic neuronal damage, iron content changes, and divalent metal transporter 1 (DMT1) in the midbrain SN of PD rats to explore the relationship between time of iron deposition and DMT1 expression. Frozen midbrain SN sections from model rats were stained with Perls' iron. Results showed massive loss of tyrosine hydroxylase (TH)-positive cells in the SN and increased DMT1 expression in model group rats. No obvious iron deposition was observed in the SN during early stages after damage, but significant iron deposition was detected at 8 weeks post-injury. Results demonstrate that the loss of TH-positive cells in the SN appeared simultaneously with increased DMT1 expression. Extensive iron deposition occurred at 8 weeks post injury, which could be regarded as an early time window of iron deposition.
文摘Parkinson's disease(PD) is the second most common age-related neurodegenerative disorder, with the clinical main symptoms caused by a loss of dopaminergic neurons in the substantia nigra, corpus striatum and brain cortex. Over 90% of patients with PD have sporadic PD and occur in people with no known family history of the disorder. Currently there is no cure for PD. Treatment with medications to increase dopamine relieves the symptoms but does not slow down or reverse the damage to neurons in the brain. Increasing evidence points to inflammation as a chief mediator of PD with inflammatory response mechanisms, involving microglia and leukocytes, activated following loss of dopaminergic neurons. Oxidative stress is also recognized as one of the main causes of PD, and excessive reactive oxygen species(ROS) and reactive nitrogen species can lead to dopaminergic neuron vulnerability and eventual death. Micro RNAs control a range of physiological and pathological functions, and may serve as potential targets for intervention against PD to mitigate damage to the brain. Several studies have demonstrated that micro RNAs can regulate oxidative stress and prevent ROS-mediated damage to dopaminergic neurons, suggesting that specific micro RNAs may be putative targets for novel therapeutic strategies in PD. Recent human and animal studies have identified a large number of dysregulated micro RNAs in PD brain tissue samples, many of which were downregulated. The dysregulated micro RNAs affect downstream targets such as SNCA, PARK2, LRRK2, TNFSF13 B, LTA, SLC5 A3, PSMB2, GSR, GBA, LAMP-2 A, HSC. Apart from one study, none of the studies reviewed had used agomirs or antagomirs to reverse the levels of downregulated or upregulated micro RNAs, respectively, in mouse models of PD or with isolated human or mouse dopaminergic cells. Further large-scale studies of brain tissue samples collected with short postmortem interval from human PD patients are warranted to provide more information on the micro RNA profiles in different brain regions and to test for gender differences.
文摘Alzheimer's disease(AD), a fatal progressive neurodegenerative disorder, has no cure to date. One of the causes of AD is the accumulation of amyloid-beta 42(Aβ42) plaques, which result in the onset of neurodegeneration. It is not known how these plaques trigger the onset of neurodegeneration. There are several animal models developed to(i) study etiology of disease,(ii) look for genetic modifiers, and(iii) identify chemical inhibitors that can block neurodegeneration and help to find cure for this disease. An insect model of Drosophila melanogaster has also provided new insights into the disease. Here we will discuss the utility of the Drosophila eye model to study Alzheimer's disease.
文摘Given the failure to develop disease-modifying therapies for Alzheimer’s disease(AD),strategies aiming at preventing or delaying the onset of the disease are being prioritized.While the debate regarding whether depression is an etiological risk factor or a prodrome of AD rages on,a key determining factor may be the timing of depression onset in older adults.There is increasing evidence that untreated early-onset depression is a risk factor and that late-onset depression may be a catalyst of cognitive decline.Data from animal studies have shown a beneficial impact of selective serotonin reuptake inhibitors on pathophysiological biomarkers of AD including amyloid burden,tau deposits and neurogenesis.In humans,studies focusing on subjects with a prior history of depression also showed a delay in the onset of AD in those treated with most selective serotonin reuptake inhibitors.Paroxetine,which has strong anticholinergic properties,was associated with increased mortality and mixed effects on amyloid and tau deposits in mice,as well as increased odds of developing AD in humans.Although most of the data regarding selective serotonin reuptake inhibitors is promising,findings should be interpreted cautiously because of notable methodological heterogeneity between studies.There is thus a need to conduct large scale randomized controlled trials with long follow up periods to clarify the dose-effect relationship of specific serotonergic antidepressants on AD prevention.
基金Supported by: the National Natural Science Foundation of China, No. 30560189the Grant from Innovation Groupfor Developing Chinese HerbsNew Drugsamong University Talents in Guangxi
文摘BACKGROUND: Modem pharmacological studies have demonstrated that Panax notoginseng saponins (PNS) can ameliorate and protect from neuropathological impairment. Whether PNS can improve the abnormality in memory and behavior of rats with Alzheimer's disease (AD) remains unclear. OBJECTIVE: Based on a Morris water maze test, this study aimed to measure improvements of spatial learning and memory by PNS in a rat model of AD, and to compare effects with huperzine A. DESIGN: A completely randomized grouping design, controlled animal experiment. SETTING: Center of Research & Development of New Drugs, Guangxi Traditional Chinese Medical University. MATERIALS: Ninety healthy Wistar rats of both genders, 15-month-old (n =75) and 3-month-old rats as young controls (n =15), were used for this study. The study was performed in accordance with animal ethics guidelines for the use and care of animals. PNS was provided by Weihe Pharmaceutical Co., Ltd (permission No. Z53021485, Yuxi, Yunan Province, China). Morris water maze equipment was provided by the Institute of Physiology, Chinese Academy of Science. METHODS: This study was performed at the Center of Research & Development of New Drugs, Guangxi Traditional Chinese Medical University from June 2003 to April 2005. Of the included rats, 15 healthy aged rats were randomly chosen as aged controls, and the remaining 60 aged rats were randomly divided into 4 groups with 15 rats in each: model group, PNS high- and low-dose groups, and an huperzine A group. Rats in the model group and the 3 treated groups were treated with intraperitoneal infusion of 9.6 g/L D-galactose (5 mL/kg) every day for 6 weeks successively to induce a subacute aging model. During week 7, animals received 1 μ L ibotenic acid (5 g/L) bilaterally into the nucleus basalis of Meynert to create a rat model of AD. The young and old rat controls received, in parallel, a corresponding volume of saline. Two weeks later, rats in the PNS high- and low-dose groups were gavaged with 200 and 100 mg/kg PNS suspension, respectively. Huperzine A suspension (0.3 mg/kg) was used in the huperzine A group. Rats in the other 3 groups were gavaged with a corresponding volume of normal saline. In each group, administration was carried out once per day for 4 consecutive weeks. MAIN OUTCOME MEASURES: After administration, learning and memory abilities were measured by place navigation and spatial probe tests. Recording indices consisted of escape latency (time-to-platform), number of times to find the platform within 2 minutes, number of times the animal crosses the original platform location, and the percent of swimming time in each quadrant. RESULTS: Several rats died due to inflammatory reactions following brain lesion or intragastric administration; therefore, 61 rats were included in the final analysis. Results of spatial navigation test: Escape latency of rats in the model group was significantly prolonged, and number of times to find the platform within 2 minutes were significantly reduced compared with other groups (both P 〈 0.05). No significant differences in these two indices were measured among the administration groups (all P 〉 0.05). Results of spatial probe test: Times for crossing the original platform location and percent of time spent in the quadrant of original platform location were significantly less in the model group than in the other groups (P 〈 0.05). There were no significant differences in these two indices among the administration groups (P 〉 0.05). CONCLUSION: PNS can remarkably improve spatial learning and memory abilities of rats with AD. The therapeutic effect of PNS is not dose-dependent and is equivalent to the effect of huperzine A.
基金supported by the Medical Scientist Training Program(T32 GM008444)Mechanistic Study of Declining Hippocampal Neurogenesis in the Aging Brain(R01AG066912 to S.G.)。
文摘Adult neurogenesis is the creation of new neurons which integrate into the existing neural circuit of the adult brain.Recent evidence suggests that adult hippocampal neurogenesis(AHN)persists throughout life in mammals,including humans.These newborn neurons have been implicated to have a crucial role in brain functions such as learning and memory.Importantly,studies have also found that hippocampal neurogenesis is impaired in neurodegenerative and neuropsychiatric diseases.Alzheimer’s disease(AD)is one of the most common forms of dementia affecting millions of people.Cognitive dysfunction is a common symptom of AD patients and progressive memory loss has been attributed to the degeneration of the hippocampus.Therefore,there has been growing interest in identifying how hippocampal neurogenesis is affected in AD.However,the link between cognitive decline and changes in hippocampal neurogenesis in AD is poorly understood.In this review,we summarized the recent literature on AHN and its impairments in AD.
文摘For decades,clinicians have developed medications and therapies to alleviate the symptoms of Parkinson’s disease,but no treatment currently can slow or even stop the progression of this localized neurodegeneration.Fortunately,sparked by the genetic revolution,stem cell reprogramming research and the advancing capabilities of personalization in medicine enable forward-thinking to unprecedented patient-specific modeling and cell therapies for Parkinson’s disease using induced pluripotent stem cells(iPSCs).In addition to modeling Parkinson’s disease more accurately than chemically-induced animal models,patient-specific stem cell lines can be created,elucidating the effects of genetic susceptibility and sub-populations’differing responses to in vitro treatments.Sourcing cell therapy with iPSC lines provides ethical advantages because these stem cell lines do not require the sacrifice of human zygotes and genetically-specific drug trails can be tested in vitro without lasting damage to patients.In hopes of finally slowing the progression of Parkinson’s disease or re-establishing function,iPSC lines can ultimately be corrected with gene therapy and used as cell sources for neural transplantation for Parkinson’s disease.With relatively localized neural degeneration,similar to spinal column injury,Parkinson’s disease presents a better candidacy for cell therapy when compared to other diffuse degeneration found in Alzheimer’s or Huntington’s Disease.Neurosurgical implantation of pluripotent cells poses the risk of an innate immune response and tumorigenesis.Precautions,therefore,must be taken to ensure cell line quality before transplantation.While cell quality can be quantified using a number of assays,a yielding a high percentage of therapeutically relevant dopaminergic neurons,minimal de novo genetic mutations,and standard chromosomal structure is of the utmost importance.Current techniques focus on iPSCs because they can be matched with donors using human leukocyte antigens,thereby reducing the severity and risk of immune rejection.In August of 2018,researchers in Kyoto,Japan embarked on the first human clinical trial using iPSC cell therapy transplantation for patients with moderate Parkinson’s disease.Transplantation of many cell sources has already proven to reduce Parkinson’s disease symptoms in mouse and primate models.Here we discuss the history and implications for cell therapy for Parkinson’s disease,as well as the necessary safety standards needed for using iPSC transplantation to slow or halt the progression of Parkinson’s disease.
文摘The pathophysiology of LaPeyronie's disease (PD) is considered to be multifactorial, involving genetic predisposition, trauma, inflammation and altered wound healing. However, these factors have not yet been validated using animal models. In this study, we have presented a new model obtained by tunica albuginea allograft. A total of 40, 16-week-old male rats were used. Of these, 8 rats served as controls and underwent a 10 × 2-mm-wide tunical excisionwith subsequent autografting, whereas the remaining 32 underwent the same excision with grafting of the defect with another rat's tunica. Morphological and functional testing was performed at 1, 3, 7 and 12 weeks after grafting. Intracavernous pressure, the degree of penile curvature and elastic fiber length were evaluated for comparison between the allograft and control groups. The tissues were obtained for histological examination. The penile curvature was significantly greater in the allografted rats as compared with the control rats. The erectile function was maintained in all rats, except in those assessed at 12 weeks. The elastin fiber length was decreased in the allografted tunica as compared to control. SMAD2 expression was detected in the inner part of the allograff, and both collagen-Ⅱ- and osteocalcin-positive cells were also noted. Tunica albuginea (TA) allograft in rats is an excellent model of PD. The persistence of curvature beyond 12 weeks and the presence of ossification in the inner layer of the TA were similar to those observed in men with PD. Validation studies using this animal model would aid understanding of the PD pathophysiology for effective therapeutic interventions.
基金Supported by the National Natural Science Foundation of China(No.39970719).
文摘AIM: To evaluate the relationship between the expression of lipopolysaccharides (LPS) binding protein (LBP) and CD14 mRNA and the severity of liver injury in alcohol-fed rats. METHODS: Twenty Wistar rats were divided into two groups:ethanol-fed group (group E) and control group (group C). Group E was fed with ethanol(5-12 g x kg(-1) x d(-1)) and group C received dextrose instead of ethanol. Rats of the two groups were sacrificed at 4 weeks and 8 weeks. Levels of endotoxin and alanine transaminase (ALT) in blood were measured, and liver pathology was observed under light and electronic microscopy. Expressions of LBP and CD14 mRNA in liver tissues were determined by RT-PCR analysis. RESULTS: Plasma endotoxin levels were increased more significantly in group E(129+/-21) ng x L(-1) and (187+/-35) ng x L(-1) at 4 and 8 wk than in control rats(48+/-9) ng x L(-1) and (53+/-11) ng x L(-1), respectively (P【0.05). Mean values of plasma ALT levels were (1867+/-250) nkat x L(-1) and (2450+/-367) nkat x L(-1) in Group E. The values were increased more dramatically in ethanol-fed rats than in Group C after 4 and 8 weeks. In liver section from ethanol-fed rats, there were marked pathological changes (steatosis, cell infiltration and necrosis). In ethanol-fed rats, ethanol administration led to a significant increase in LBP and CD14 mRNA levels compared with the control group (P【0.05). CONCLUSION: Ethanol administration led to a significant increase in endotoxin levels in serum and LBP and CD14 mRNA expressions in liver tissues. The increase of LBP and CD14 mRNA expression might wake the liver more sensitive to endotoxin and liver injury.
基金supported by"H+Die Spitaler der Schweiz" the Swiss Agency for Development and Cooperation(DEZA)by the University Hospital Zurich/Switzerland
文摘MOLECULAR PHYSIOLLGY OF HEPATOCELLULAR TRANSPORT PROTEINS Basolaferal transport systems Na+-dependent bile salt uptake Uptake of bile salts into the liver was first isolated perfused rat liver[1],isolated hepatocyte cultures and basolateral plasma membrane vesicles [2,4].
基金Supported by DGAPA-PAPIIT,No.IN207116CONACyT,No.179927
文摘Cell grafting has been considered a therapeutic approach for Parkinson's disease(PD) since the 1980 s. The classical motor symptoms of PD are caused by the loss of dopaminergic neurons in the substantia nigra pars compacta, leading to a decrement in dopamine release in the striatum. Consequently, the therapy of celltransplantation for PD consists in grafting dopamineproducing cells directly into the brain to reestablish dopamine levels. Different cell sources have been shown to induce functional benefits on both animal models of PD and human patients. However, the observed motor improvements are highly variable between individual subjects, and the sources of this variability are not fully understood. The purpose of this review is to provide a general overview of the pioneering studies done in animal models of PD that established the basis for the first clinical trials in humans, and compare these with the latest findings to identify the most relevant aspects that remain unanswered to date. The main focus of the discussions presented here will be on the mechanisms associated with the survival and functionality of the transplants. These include the role of the dopamine released by the grafts and the capacity of the grafted cells to extend fibers and to integrate into the motor circuit. The complete understanding of these aspects will require extensive research on basic aspects of molecular and cellular physiology, together with neuronal network function, in order to uncover the real potential of cell grafting for treating PD.