铅暴露大鼠脑不同区域NMDA受体亚基(NR1、NR2A、NR2B)表达的研究

目的:观察铅暴露大鼠中不同脑区NMDAR1(NR1)、NMDAR2A(NR2A)和NMDAR2B(NR2B)亚基蛋白和mRNA水平的表达情况。方法:采用Western Blot及RT-PCR技术,测定NR1、NR2A和NR2B亚基蛋白和mRNA在铅暴露大鼠脑中额叶皮质、新小脑、海马及纹状体中的表达情况。结果:铅暴露大鼠中NR1、NR2A和NR2B亚基的蛋白水平和mRNA表达在各个脑区均有不同程度的下调。结论:在铅暴露大鼠的额叶皮质、海马、新小脑和纹状体中,NMDA受体亚基NR1,NR2A和NR2B的表达在mRNA水平就已经发生了改变。

Knowledge domain and emerging trends in Alzheimer’s disease: a scientometric review based on CiteSpace analysis

Alzheimer’s disease is the most common cause of dementia.It is an increasingly serious global health problem and has a significant impact on individuals and society.However,the precise cause of Alzheimer’s disease is still unknown.In this study,11,748 Web-of-Science-indexed manuscripts regarding Alzheimer’s disease,all published from 2015 to 2019,and their 693,938 references were analyzed.A document co-citation network map was drawn using CiteSpace software.Research frontiers and development trends were determined by retrieving subject headings with apparent changing word frequency trends,which can be used to forecast future research developments in Alzheimer’s disease.

Diagnosis and treatment of congenital choledochal cyst: 20 years' experience in China

AIM To summarize the experience of diagnosis and treatment of congenital choledochal cyst in the past 20years ( 1980 2000).``METHODS The clinical data of 108 patients admitted from 1980 to 2000 were analyzed retrospectively.RESULTS Abdominal pain, jaundice and abdominal mass were presented in most child cases. Clinical symptoms in adult cases were non-specific, resulting in delayed diagnosis frequently. Fifty-seven patients (52.7%) had coexistent pancreatiobiliary disease. Carcinoma of the biliary duct occurred in 18 patients (16.6%). Ultrasonic examination was undertaken in 94 cases, ERCP performed in 46 cases and CT in 71 cases. All of the cases were correctly diagnosed before operation. Abnormal pancreatobiliary duct junction was found in .39 patients.Before 1985 the diagnosis and classification of congenital choledochal cyst were established by ultrasonography preoperatively and confirmed during operation, the main procedures were internal drainage by cyst enterostomy.After 1985, the diagnosis was established by ERCP and CT. and cystectomy with Roux-en-Y hepaticojejunostomy was the conventional procedures. In 1994, we reported a new and simplified operative procedure in order to reduce the risk of choledochal cyst malignancy. Postoperative complication was mainly retrograde infection of biliary tract, which could be controlled by the administration of antibiotics, there was no perioperative mortality.``CONCLUSION The concept in diagnosis and treatment of congenital choledochal cyst has obviously been changed greatly. CT and ERCP were of great help in the classification of the disease. Currently, cystectomy with Roux-en-Y hepaticojejunostomy is strongly recommended as the choice for patients with type I and type Ⅳ cysts.Piggyback orthotopic liver transplantation is indicated in type \ cysts (Carolis disease) with frequently recurrent cholangitis.

Neuroprotective mechanism of Kai Xin San: upregulation of hippocampal insulin-degrading enzyme protein expression and acceleration of amyloid-beta degradation

Kai Xin San is a Chinese herbal formula composed of Radix Ginseng, Poria, Radix Polygalae and Acorus Tatarinowii Rhizome. It has been used in China for many years for treating amnesia. Kai Xin San ameliorates amyloid-β （Aβ） induced cognitive dysfunction and is neuroprotective in vivo, but its precise mechanism remains unclear. Expression of insulin-degrading enzyme （IDE）, which degrades Aβ, is strongly correlated with cognitive function. Here, we injected rats with exogenous Aβ42 （200 μM, 5 μL） into the hippocampus and subsequently administered Kai Xin San （0.54 or 1.08 g/kg/d） intragastrically for 21 consecutive days. Hematoxylin eosin and Nissl staining revealed that Kai Xin San protected neurons against Aβ-induced damage. Furthermore, enzyme linked immunosorbent assay, western blot and polymerase chain reaction results showed that Kai Xin San decreased Aβ42 protein levels and increased expression of IDE protein, but not mRNA, in the hippocampus. Our findings reveal that Kai Xin San facilitates hippocampal Aβ degradation and increases IDE expression, which leads, at least in part, to the alleviation of hippocampal neuron injury in rats.

Optogenetics and its application in neural degeneration and regeneration

Neural degeneration and regeneration are important topics in neurological diseases. There are limited options for therapeutic interventions in neurological diseases that provide simultaneous spatial and temporal control of neurons. This drawback increases side effects due to non-specific targeting. Optogenetics is a technology that allows precise spatial and temporal control of cells. Therefore, this technique has high potential as a therapeutic strategy for neurological diseases. Even though the application of optogenetics in understanding brain functional organization and complex behaviour states have been elaborated, reviews of its therapeutic potential especially in neurodegeneration and regeneration are still limited. This short review presents representative work in optogenetics in disease models such as spinal cord injury, multiple sclerosis, epilepsy, Alzheimer＇s disease and Parkinson＇s disease. It is aimed to provide a broader perspective on optogenetic therapeutic potential in neurodegeneration and neural regeneration.

Micro RNA-124 slows down the progression of Huntington's disease by promoting neurogenesis in the striatum

MicroRNA-124 contributes to neurogenesis through regulating its targets, but its expression both in the brain of Huntington＇s disease mouse models and patients is decreased. However, the effects of microRNA-124 on the progression of Huntington＇s disease have not been reported. Results from this study showed that microRNA-124 increased the latency to fall for each R6/2 Hunting- ton＇s disease transgenic mouse in the rotarod test. 5-Bromo-2＇-deoxyuridine （BrdU） staining of the striatum shows an increase in neurogenesis. In addition, brain-derived neurotrophic factor and peroxisome proliferator-activated receptor gamma coactivator 1-alpha protein levels in the striatum were increased and SRY-related HMG box transcription factor 9 protein level was de- creased. These findings suggest that microRNA-124 slows down the progression of Huntington＇s disease possibly through its important role in neuronal differentiation and survival.

Effects of triptolide on hippocampal microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer＇s disease

The principal pathology of Alzheimer＇s disease includes neuronal extracellular deposition of amyloid-beta peptides and formation of senile pl aques, which in turn induce neuroinflammation in the brain. Triptolide, a natural extract from the vine-like herb Tripterygium wilfordii Hook F, has potent anti-inflammatory and immunosuppressive efficacy. Therefore, we determined if triptolide can inhibit activation and proliferation of microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer＇s disease. We used 1 or 5 μg/kg/d triptolide to treat APP/PS1 double transgenic mice （aged 4-4.5 months） for 45 days. Unbiased stereology analysis found that triptolide dose-dependent- ly reduced the total number of microglial cells, and transformed microglial cells into the resting state. Further, triptolide （5 μg/kg/d） also reduced the total number of hippocampal astrocytes. Our in vivo test results indicate that triptolide suppresses activation and proliferation of microglial cells and astrocytes in the hippocampus of APP/PS 1 double transgenic mice with Alzheimer＇s disease.

Neuroprotective potential of Quercetin in combination with piperine against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity

1-Methy-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP）is a neurotoxin that selectively damages dopaminergic neurons in the substantia nigra pars compacta and induces Parkinson＇s like symptoms in rodents.Quercetin（QC）is a natural polyphenolic bioflavonoid with potent antioxidant and anti-inflammatory properties but lacks of clinical attraction due to low oral bioavailability.Piperine is a well established bioavailability enhancer used pre-clinically to improve the bioavailability of antioxidants（e.g.,Quercetin）.Therefore,the present study was designed to evaluate the neuroprotective potential of QC together with piperine against MPTP-induced neurotoxicity in rats.MPTP（100μg/μL/rat,bilaterally）was injected intranigrally on days 1,4 and 7 using a digital stereotaxic apparatus.QC（25 and 50 mg/kg,intragastrically）and QC（25 mg/kg,intragastrically）in combination with piperine（2.5 mg/kg,intragastrically）were administered daily for 14 days starting from day 8 after the 3^（rd） injection of MPTP.On day 22,animals were sacrificed and the striatum was isolated for oxidative stress parameter（thiobarbituric acid reactive substances,nitrite and glutathione）,neuroinflammatory cytokine（interleukin-1β,interleukin-6,and tumor necrosis factor-α）and neurotransmitter（dopamine,norepinephrine,serotonin,gamma-aminobutyric acid,glutamate,3,4-dihydroxyphenylacetic acid,homovanillic acid,and 5-hydroxyindoleacetic acid）evaluations.Bilateral infusion of MPTP into substantia nigra pars compacta led to significant motor deficits as evidenced by impairments in locomotor activity and rotarod performance in open field test and grip strength and narrow beam walk performance.Both QC（25 and 50 mg/kg）and QC（25 mg/kg）in combination with piperine（2.5 mg/kg）,in particular the combination therapy,significantly improved MPTP-induced behavioral abnormalities in rats,reversed the abnormal alterations of neurotransmitters in the striatum,and alleviated oxidative stress and inflammatory response in the striatum.These findings indicate that piperine can enhance the antioxidant and anti-inflammatory properties of QC,and QC in combination with piperine exhibits strong neuroprotective effects against MPTP-induced neurotoxicity.

Targeting β-secretase with RNAi in neural stem cells for Alzheimer's disease therapy

There are several major pathological changes in Alzheimer＇s disease, including apoptosis of cho- linergic neurons, overactivity or overexpression of 13-site amyloid precursor protein cleaving enzyme 1 （BACE1） and inflammation. In this study, we synthesized a 19-nt oligonucleotide targeting BACE1, the key enzyme in amyloid beta protein （AI3） production, and introduced it into the pSilenCircle vector to construct a short hairpin （shRNA） expression plasmid against the BACE1 gene. We transfected this vector into C17.2 neural stem cells and primary neural stem cells, resulting in downregulation of the BACE1 gene, which in turn induced a considerable reduction in reducing AI3 protein production. We anticipate that this technique combining cell transplantation and gene ther- apy will open up novel therapeutic avenues for Alzheimer＇s disease, particularly because it can be used to simultaneously target several pathogenetic changes in the disease.

Neuroprotective effects of berry fruits on neurodegenerative diseases

Recent clinical research has demonstrated that berry fruits can prevent age-related neurodegenerative diseases and improve motor and cognitive functions. The berry fruits are also capable of modulating signaling pathways involved in inflammation, cell survival, neurotransmission and enhancing neuroplasticity. The neuroprotective effects of berry fruits on neurodegenerative diseases are related to phytochemicals such as anthocyanin, caffeic acid, catechin, quercetin, kaempferol and tannin. In this review, we made an attempt to clearly describe the beneficial effects of various types of berries as promising neuroprotective agents.

Treating Alzheimer's disease with Yizhijiannao granules by regulating expression of multiple proteins in temporal lobe

Yizhijiannao granules have been shown to improve cognitive function in Alzheimer＇s disease patients. The present study sought to explore the mechanisms involved in the cognitive enhancing effects of Yizhijiannao granule. Senescence-accelerated mouse prone 8 mice with learning and memory disorders were intragastrically treated with Yizhijiannao granule for 8 weeks. Mice intragastrically treated with double distilled water for 8 weeks were considered as the control group. 2D gel electrophoresis was used to isolate total protein from the temporal lobe of senescence-accelerated mouse prone 8 mice, and differential protein spots were obtained by mass spectrometry. Thirty-seven differential protein spots were found in the temporal lobe area of both groups. Ten protein spots were identified： high mobility group box 1, dimethylarginine dimethylaminohydrolase-1, nenroglobin, hemoglobin beta adult major chain, peroxiredoxin-6, cofilin-1, flotiUin 1, peptidylprolyl isomerase A, voltage-dependent anion channel-2 and chaperonin containing TCP1, and subunit 2. Among other functions, these proteins are separately involved in the regulation of amyloid beta production, oxidative stress, neuroinflammation, regulation of tau phosphorylation, and regulation of neuronal apoptosis. Our results revealed that Yizhijiannao granule can regulate the expression of various proteins in the temporal lobe of senescence-accelerated mouse prone 8 mice, and may be therapeutically beneficial for the treatment of Alzheimer＇s disease.

Influence of RNA interference on the mitochondrial subcellular localization of alpha-synuclein and on the formation of Lewy body-like inclusions in the cytoplasm of human embryonic kidney 293 cells induced by the overexpression of alphasynuclein

The specific and effective a-synuclein RNA interference （RNAi） plasmids, and the a-synuclein-pEGFP recombinant plasmids were co-transfected into human embryonic kidney 293 （HEK293） cells using the lipofectamine method. Using an inverted fluorescence microscope, a-synuclein proteins were observed to aggregate in the cytoplasm and nucleus. Wild-type a-synuclein proteins co-localized with mitochondria. Hematoxylin-eosin staining revealed round eosinophilic bodies （Lewy body-like inclusions） in the cytoplasm of some cells transfected with a-synuclein-pEGFP plasmid. However, the formation of Lewy body-like inclusions was not observed following transfection with the RNAi pSYN-1 plasmid. RNAi blocked Lewy body-like inclusions in the cytoplasm of HEK293 cells induced by wild-type a-synuclein overexpression, but RNAi did not affect the subcellular localization of wild-type a-synuclein in mitochondria.

Crypt abscess-associated microbiota in inflammatory bowel disease and acute self-limited colitis

AIM:To evaluate whether crypt abscesses frominflammatory bowel disease(IBD)patients containbacteria and to establish their nature.METHODS:We studied 17 ulcerative colitis patients,11 Crohn's disease patients,7 patients with acute selflimited colitis(ASLC)and normal colonic biopsies from5 subjects who underwent colonoscopy for colon cancer screening.A fluorescent in situ hybridization techniquewas applied to colonic biopsies to assess the microbiotacomposition of the crypts and crypt abscesses.RESULTS:Crypts colonized by bacteria were observedin 42.9%and 3.6%of ASLC and IBD patients,respectively(P=0.019).Crypt abscesses colonized bybacteria were observed in 28.6%and 0.0%of ASLCand IBD patients,respectively(P=0.035).CONCLUSION:These results do not support thehypothesis that crypt abscesses in IBD are the resultof localized dysbiosis arising from persistence of livingbacteria colonizing the crypts.

Magnetic resonance morphometry of the loss of gray matter volume in Parkinson's disease patients

Voxel-based morphometry can be used to quantitatively compare structural differences and func-tional changes of gray matter in subjects. In the present study, we compared gray matter images of 32 patients with Parkinson’s disease and 25 healthy controls using voxel-based morphometry based on 3.0 T high-field magnetic resonance T1-weighted imaging and clinical neurological scale scores. Results showed that the scores in Mini-Mental State Examination and Montreal Cognitive Assessment were lower in patients compared with controls. In particular, the scores of visuospatial/executive function items in Montreal Cognitive Assessment were significantly reduced, but mean scores of non-motor symptoms significantly increased, in patients with Parkinson’s dis-ease. In addition, gray matter volume was significantly diminished in Parkinson’s disease patients compared with normal controls, including bilateral temporal lobe, bilateral occipital lobe, bilateral parietal lobe, bilateral frontal lobe, bilateral insular lobe, bilateral parahippocampal gyrus, bilateral amygdale, right uncus, and right posterior lobe of the cerebel um. These findings indicate that voxel-based morphometry can accurately and quantitatively assess the loss of gray matter volume in patients with Parkinson＇s disease, and provide essential neuroimaging evidence for multisystem pathological mechanisms involved in Parkinson’s disease.

Mutant Huntingtin Causes a Selective Decrease in the Expression of Synaptic Vesicle Protein 2C

Huntington＇s disease （HD） is a neurodegenera- tive disease caused by a polyglutamine expansion in the huntingtin （Htt） protein. Mutant Htt causes synaptic transmission dysfunctions by interfering in the expression of synaptic proteins, leading to early HD symptoms. Synaptic vesicle proteins 2 （SV2s）, a family of synaptic vesicle proteins including 3 members, SV2A, SV2B, and SV2C, plays important roles in synaptic physiology. Here, we investigated whether the expression of SV2s is affected by mutant Htt in the brains of HD transgenic （TG） mice and Neuro2a mouse neuroblastoma cells （N2a cells） expressing mutant Htt. Western blot analysis showed that the protein levels of SV2A and SV2B were not signifi- cantly changed in the brains of HD TG mice expressing mutant Htt with 82 glutamine repeats. However, in the TG mouse brain there was a dramatic decrease in the protein level of SV2C, which has a restricted distribution pattern in regions particularly vulnerable in HD. Immunostaining revealed that the immunoreactivity of SV2C was progres- sively weakened in the basal ganglia and hippocampus of TG mice. RT-PCR demonstrated that the mRNA level of SV2C progressively declined in the TG mouse brain without detectable changes in the mRNA levels of SV2A and SV2B, indicating that mutant Htt selectively inhibits the transcriptional expression of SV2C. Furthermore, we found that only SV2C expression was progressively inhibited in N2a cells expressing a mutant Htt containing 120 glutamine repeats. These findings suggest that the synaptic dysfunction in HD results from the mutant Htt- mediated inhibition of SV2C transcriptional expression. These data also imply that the restricted distribution and decreased expression of SV2C contribute to the brain region-selective pathology of HD.