A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

Location and expression of neurotrophin-3 and its receptor in the brain of human embryos during early development

BACKGROUND： Cell culture in vitro trials have demonstrated that neurotrophin-3 （NT-3） can enhance the survival of sensory neurons and sympathetic neurons, and can also support embryo-derived motor neurons. This effect is dependent on nerve growth factor on the surface of cells. Understanding the role of NT-3 and its receptor in the early development of human embryonic brains will help to investigate the correlation between early survival of nerve cells and the microenvironment of neural regeneration. OBJECTIVE： To observe the proliferation of cerebral neurons in the development of human embryonic brain, and to investigate the location, expression and distribution of NT-3 and its receptor TrkC during human brain development. DESIGN, TIME AND SETTING： An observation study on cells was performed in the Department of ttuman Anatomy, Histology and Embryology, Chengdu Medical College in September 2007. MATERIALS： Fifteen specimens of flesh human embryo, aged 6 weeks, were used in this study. METHODS： The proliferation of cerebral neurons was detected using proliferating cell nuclear antigen, and the immunocytochemistry ABC technique was applied to observe the location, expression and distribution of NT-3 and its receptor TrkC in the brain of the human embryo. MAIN OUTCOME MEASURES： Location, expression and distribution of NT-3 and its receptor in the brain of the human embryo. RESULTS： In the early period （aged 6 weeks） of human embryonic development, proliferating cell nuclear antigen-positive reactive substances were mainly observed in the nucleus of the forebrain ventricular zone and subventricular zone, and the intensity was stronger in the subventricular zone than the forebrain ventricle. NT-3 positive reactive substance was mainly distributed in the cytoblastema of the forebrain neuroepithelial layer and nerve cell process, while TrkC was mainly distributed in the cell membrane of the forebrain ventricular zone and subventricular zone. During embryonic development, NT-3 and TrkC showed a positive immune reaction to a greater or lesser extent in ependymal epithelium. CONCLUSION： During early human embryonic development, cerebral nerve cells proliferate in the ventricular zone and subventricular zone, and NT-3 is expressed in the neural axon. The results show that the highly expressed NT-3 could promote the proliferation of neural axons and maintain the neuron body＇s survival.

Possible mechanisms of lycopene amelioration of learning and memory impairment in rats with vascular dementia

Oxidative stress is involved in the pathogenesis of vascular dementia. Studies have shown that lycopene can significantly inhibit oxidative stress;therefore, we hypothesized that lycopene can reduce the level of oxidative stress in vascular dementia. A vascular dementia model was established by permanent bilateral ligation of common carotid arteries. The dosage groups were treated with lycopene(50, 100 and 200 mg/kg) every other day for 2 months. Rats without bilateral carotid artery ligation were prepared as a sham group. To test the ability of learning and memory, the Morris water maze was used to detect the average escape latency and the change of search strategy. Hematoxylin-eosin staining was used to observe changes of hippocampal neurons. The levels of oxidative stress factors, superoxide dismutase and malondialdehyde, were measured in the hippocampus by biochemical detection. The levels of reactive oxygen species in the hippocampus were observed by dihydroethidium staining. The distribution and expression of oxidative stress related protein, neuron-restrictive silencer factor, in hippocampal neurons were detected by immunofluorescence histochemistry and western blot assays. After 2 months of drug administration,(1) in the model group, the average escape latency was longer than that of the sham group, and the proportion of straight and tend tactics was lower than that of the sham group, and the hippocampal neurons were irregularly arranged and the cytoplasm was hyperchromatic.(2) The levels of reactive oxygen species and malondialdehyde in the hippocampus of the model group rats were increased, and the activity of superoxide dismutase was decreased.(3) Lycopene(50, 100 and 200 mg/kg) intervention improved the above changes, and the lycopene 100 mg/kg group showed the most significant improvement effect.(4) Neuron-restrictive silencer factor expression in the hippocampus was lower in the sham group and the lycopene 100 mg/kg group than in the model group.(5) The above data indicate that lycopene 100 mg/kg could protect against the learning-memory ability impairment of vascular dementia rats. The protective mechanism was achieved by inhibiting oxidative stress in the hippocampus. The experiment was approved by the Animal Ethics Committee of Fujian Medical University, China(approval No. 2014-025) in June 2014.

Principle of relative positioning of structures in the human body

The arrangement of various biological structures should generally ensure the safety of crucial structures and increase their working efficiency; however, other principles governing the relative positions of structures in humans have not been reported. The present study therefore investigated other principles using nerves and their companion vessels in the human body as an example. Nerves and blood vessels usually travel together and in the most direct way towards their targets. Human embryology, histology, and gross anatomy suggest that there are many possible positions for these structures during development. However, for mechanical reasons, tougher or stronger structures should take priority. Nerves are tougher than most other structures, followed by arteries, veins, and lymphatic vessels. Nerves should therefore follow the most direct route, and be followed by the arteries, veins, and lymphatic vessels. This general principle should be applicable to all living things.

Developmental Temporal Patterns and Molecular Network Features in the Transcriptome of Rat Spinal Cord

The molecular network features of spinal cord development that are integral to tissue engineering remain poorly understood in placental mammals,especially in terms of their relationships with vital biological processes such as regeneration.Here,using a large-scale temporal transcriptomic analysis of rat spinal cord from the embryonic stage to adulthood,we show that fluctuating RNA expression levels reflect highly active transcriptional regulation,which may initiate spinal cord patterning.We also demonstrate that microRNAs(miRNAs)and transcriptional factors exhibit a mosaic profile based on their expression patterns,while differential alternative splicing events reveal that alternative splicing may be a driving force for the development of the node of Ranvier.Our study also supports the existence of a negative correlation between innate immunity and intrinsic growth capacity.Epigenetic modifications appear to perform their respective regulatory functions at different stages of development,while guanine nucleotidebinding protein(G protein)-coupled receptors(including olfactory receptors(ORs))may perform pleiotropic roles in axonal growth.This study provides a valuable resource for investigating spinal cord development and complements the increasing number of single-cell datasets.These findings also provide a genetic basis for the development of novel tissue engineering strategies.

Relationship of recurrent laryngeal nerve with inferior horn of thyroid cartilage,inferior thyroid artery,berry's ligament and Zuckerkandl's tubercle:A study in corpses

The pivotal role of four anatomical landmarks:inferior horn of thyroid cartilage,inferior thyroid artery(ITA),Berry's ligament(BL)and Zuckerkandl's tubercle(ZT)on recurrent laryngeal nerve(RLN)protection has received more attention.In our study,anatomy of 14 specimens(28 sides in total)were dissected to investigate the relationship between RLN and these four landmarks.

PROPERTIES OF PROLIFERATION AND DIFFERENTIATION OF NEONATAL RAT RETINAL PROGENITOR CELLS IN VITRO

Objective To investigate the properties of proliferation and differentiation of neonatal rat retinal progenitor cells (RPCs) in vitro. Methods RPCs were isolated from neonatal SD rats neural retina and cultured in DMEM/F12+N2 with EGF and bFGF (suspension medium )or 10%FBS without EGF and bFGF (differentiation medium). The cells grew as suspended spheres or adherent monolayers, depending on different culture conditions. The neural stem cells or retinal progenitors, neurons, astrocytes, retinal ganglion cells, rod photoreceptors and the proliferating cells were evaluated with immunofluorescence analysis by Nestin or Pax6, Map2, GFAP, Thy-1, Rhodopsin and BrdU antibodies respectively. Results RPCs could propagate and differentiate in suspension or differentiation medium and express the markers of Nestin (92.86%) or Pax6 (86.75%), Map2 (38.54%), GFAP (20.93%), Thy-1 (27.66%) and Rhodopsin(13.33%)in suspension medium; however, Nestin (60.27%), Pax6 (52%), Map2 (34.94%), GFAP (38.17%), Thy-1(30.84%) and Rhodopsin (34.67%) in differentiation medium. 96.4% of the population in the neurospheres was BrdU-positive cells. The cells could spontaneously adherent forming some subspheres and retinal specific cell types. Conclusion Neonatal rat RPCs possess the high degree of proliferation and can differentiate into neurons, astrocytes, retinal ganglion cells and rod photoreceptors in vitro. There are different proportions for RPCs to differentiate into specific cell types.

Silencing of LRP1 exacerbates inflammatory response via TLR4-mediated NF-κB and MAPKs signaling pathways in APP/PSI transgenic mice

Activation of glial cells(including microglia and astrocytes)appears central to the initiation and progression of neuroinflammation in Alzheimer's disease(AD).The low-density lipoprotein receptor related protein 1(LRP1)is a major receptor for amyloid-β(Aβ),which plays a critical role in AD pathogenesis.LRP1 regulates inflammatory response by modulating the release of pro-inflammatory cytokines and phagocytosis.However,the effects of LRP1 on microglia and astrocytic cells mediated neuroinflammation and their underlying mechanisms in AD remain unclear.

Research status and hotspot analysis of body donation in China:A CiteSpace-based study

To provide references by analyzing the history,hotspot,and trend of the research in body donation,CiteSpace software was used to conduct a co occurrence network analysis,and 196 articles in CNKI database were included.With the increasing number of articles in recent years,“Political and legal organizations”and“medical schools and departments”were main research institutions.

Data mining in clinical big data:the frequently used databases,steps,and methodological models

Many high quality studies have emerged from public databases,such as Surveillance,Epidemiology,and End Results(SEER),National Health and Nutrition Examination Survey(NHANES),The Cancer Genome Atlas(TCGA),and Medical Information Mart for Intensive Care(MIMIC);however,these data are often characterized by a high degree of dimensional heterogeneity,timeliness,scarcity,irregularity,and other characteristics,resulting in the value of these data not being fully utilized.Data-mining technology has been a frontier field in medical research,as it demonstrates excellent performance in evaluating patient risks and assisting clinical decision-making in building disease-prediction models.Therefore,data mining has unique advantages in clinical big-data research,especially in large-scale medical public databases.This article introduced the main medical public database and described the steps,tasks,and models of data mining in simple language.Additionally,we described data-mining methods along with their practical applications.The goal of this work was to aid clinical researchers in gaining a clear and intuitive understanding of the application of data-mining technology on clinical big-data in order to promote the production of research results that are beneficial to doctors and patients.

Lipid rafts participate in aberrant degradative autophagic-lysosomal pathway of amyloid-beta peptide in Alzheimer's disease

Amyloid-beta peptide is the main component of amyloid plaques, which are found in Alzhei- mer＇s disease. The generation and deposition of amyloid-beta is one of the crucial factors for the onset and progression of Alzheimer＇s disease. Lipid rafts are glycolipid-rich liquid domains of the plasma membrane, where certain types of protein tend to aggregate and intercalate. Lipid rafts are involved in the generation of amyloid-beta oligomers and the formation of amyloid-beta peptides. In this paper, we review the mechanism by which lipid rafts disturb the aberrant deg- radative autophagic-lysosomal pathway of amyloid-beta, which plays an important role in the pathological process of Alzheimer＇s disease. Moreover, we describe this mechanism from the view of the Two-system Theory of fasciology and thus, suggest that lipid rafts may be a new target of Alzheimer＇s disease treatment.

Effects of Rat Cytomegalovirus on the Nervous System of the Early Rat Embryo

The purpose of the study was to investigate the impact of rat cytomegalovirus （RCMV） infection on the development of the nervous system in rat embryos, and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1 （Ngnl） in RCMV infected neural stem cells （NSCs）. Infection and control groups were established, each containing 20 pregnant Wistar rats. Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy. Rat E20 embryos were taken to evaluate the teratogenic rate. NSCs were isolated from El3 embryos, and maintained in vitro. We found： 1） Poor fetal development was found in the infection group with low survival and high malformation rates. 2） The proliferation and differentiation of NSCs were affected. In the infection group, NSCs proliferated more slowly and had a lower neurosphere formation rate than the control. The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control, showed by immunofluorescenee staining. 3） Ngnl mRNA expression and the nuclear p-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated. 4） The Morris water maze test was performed on 4-week pups, and the infected rats were found worse in learning and memory ability. In a summary, RCMV infection caused abnormalities in the rat embryonic nervous system, significantly inhibited NSC proliferation and differentiation, and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation. This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.

Identification of novel Lynch syndrome mutations in Chinese patients with endometriod endometrial cancer

Objective:Lynch syndrome(LS)predisposes patients to early onset endometrioid endometrial cancer(EEC).However,little is known about LS-related EEC in the Chinese population.The aim of this study was to investigate the prevalence of LS and to identify the specific variants of LS in Chinese patients with EEC.Methods:We applied universal immunohistochemistry screening to detect the expression of mismatch repair(MMR)proteins,which was followed by MLH1 methylation analysis to identify suspected LS cases,next-generation sequencing(NGS)to confirm LS,and microsatellite instability(MSI)analysis to verify LS.Results:We collected 211 samples with EEC.Twenty-seven(27/211,12.8%)EEC cases had a loss of MMR protein expression.After MLH1 methylation analysis,16 EEC cases were suggested to be associated with LS.Finally,through NGS and MSI analysis,we determined that 10 EEC(10/209,4.78%)cases were associated with LS.Among those cases,3 unreported mutations(1 frameshift and 2 nonsense)were identified.M SH6 c.597_597delC,found in 4 patients,is likely to be a founder mutation in China.Conclusions:We demonstrated the feasibility of a process for LS screening in Chinese patients with EEC,by using universal immunohistochemistry screening followed by MLH1 methylation analysis and confirmation through NGS and MSI analysis.The novel mutations identified in this study expand knowledge of LS.

Suppression of TLR4-MyD88 signaling pathway attenuated chronic mechanical pain in a rat model of endometriosis

The specific role of TLR4 signaling in the pain symptom of endometriosis(EM)remains obscure.The rat endometriosis model was established by transplanting uterine horn tissue into gastrocnemius.W estern blotting and/or immunofluorescent staining were applied to detect high mobility group box 1(HMGB1),TLR4,myeloid differentiation factor-88 adaptor protein(MyD88),and nuclear factor kappa-B-p65(NF-kB-p65)expression,as well as the activation of astrocyte and microglia.The antagonist of TLR4(LPS-RS-Ultra,LRU)and MyD88 homodimerization inhibitory peptide(MIP)were intrathecally administrated to assess the behavioral effects of blocking TLR4 signaling on endometriosis-related pain.We found that HMGB1 was upregulated in the implanted uterine tissue,dorsal root ganglion(DRG),and.

Four and a half LIM domains protein 1 can be as a double-edged sword in cancer progression

Four and a half LIM domains protein 1(FH L1),as the name suggests,contains four and a half LIM domains capable o f interacting with various molecules,including structural proteins,kinases,and transcriptional machinery.FHL1 contains a zinc-finger domain and performs diverse roles in regulation of gene transcription,cytoarchitecture,cell proliferation,and signal transduction.Several studies have validated the importance of FHL1 in muscle development,myopathy,and cardiovascular diseases.Mutations in the FHL1 gene are associated with various myopathies.Recently,FHL1 was identified as a major host factor for chikungunya virus(CHIKV)infection in both humans and mice.Based on more recent findings over the last decade,FHL1 is proposed to play a dual role in cancer progression.On the one hand,FHL1 expression is suppressed in several cancer types,which correlates with increased metastatic disease and decreased survival.Moreover,FHL1 is reported to inhibit tum or cell growth and migration by associating with diverse signals,such as TGF-P and ER,and therefore considered a tumor suppressor.On the other hand,FHL1 can function as an oncogenic protein that promotes tumor progression upon phosphorylation,reflecting complex roles in cancer.This review primarily focuses on the dual role and underlying mechanisms of action of FHL1 in human cancer progression and its clinical relevance.

THE EFFECT OF LIGUSTRAZINE ON NEUROGENESIS IN CORTEX AFTER FOCAL CEREBRAL ISCHEMIA IN RATS

Objective To explore the effect of Ligustrazine on neurogenesis in cortex after focal cerebral ischemia in rats. Methods Focal cerebral ischemia was induced by left middle cerebral artery occlusion with a suture. Two hours later, injection of Ligustrazine (80mg/kg, 1 time/d) was performed peritoneally. Four hours after the ischemia, 5-bromodeoxyuridine (BrdU) (50mg/kg, 1 time/d) was injected peritoneally. At 7d, 14d and 21d after ischemia, BrdU positive cells in the cortex were observed by immunohistochemical staining. Results In ischemic model group, at 7 day, sparsely-distributed BrdU positive cells were observed in the Ⅱ-Ⅵ layers of the ipsilateral cortex, with a band-like distribution in ischemic penumbra. With the prolongation of ischemia, the number of BrdU positive cells increased. In Ligustrazine group, BrdU positive cells were also observed in the Ⅱ-Ⅵ layers of the cortex, with an intense distribution in ischemic penumbra. The numbers of BrdU positive cells at 7d, 14d and 21d were more than those in ischemic model group respectively. Conclusion Ligustrazine increases the proliferated cells in cortex after focal cerebral ischemia in rats. The results suggest that it may be useful for promoting self-repair after ischemia.

Association between drinking behavior and sleep duration in Chinese adults: findings from the China Health and Nutrition Survey

Background:To examine the association between alcohol drinking and short sleep duration among Chinese adults.Methods:Based on inclusion and exclusion criteria,28,167 records of 15,074 adults longitudinal data were obtained from the China Health and Nutrition Survey for the period from 2004 to 2011.A multilevel logistic regression model was employed to explore the association between alcohol drinking and sleep duration.Results:Compared with nondrinking participants,a high drinking frequency was positively correlated with a short sleep duration in both the males(odds ratio(OR)=1.33,95%confidence interval(CI)=1.20–1.48,P<0.001)and females(OR=1.60,95%CI=1.18–2.18,P=0.003)before the covariates were adjusted.After adjusting for age,residence area,education level,marital status,smoking,coffee consumption,tea consumption,and activity level,this association remained significant in the males(OR=1.31,95%CI=1.17–1.46,P<0.001)but not in the females(OR=1.16,95%CI=0.85–1.59,P=0.340).Conclusion:The present results suggest that a high drinking frequency was positively correlated with a short sleep duration in male population.Comprehensive measures therefore need to be implemented to improve sleep duration,especially to increase awareness of the dangers of drinking alcohol.

Mutation analysis of FBN1 gene in two Chinese families with congenital ectopia lentis in northern China

AIM: To summarize the phenotypes and identify the underlying genetic cause of the fibrillin-1(FBN1) gene responsible for congenital ectopia lentis(EL) in two Chinese families in northern China.METHODS: A detailed family history and clinical data from all participants were collected by clinical examination. The candidate genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. Haplotyping was used to confirm the mutation sequence. Real-time PCR was used to determine the FBN1 messenger ribonucleic acid(m RNA) levels in patients with EL and in unaffected family members.RESULTS: The probands and other patients in the two families were affected with congenital isolated EL. A heterozygous FBN1 mutation in exon 21(c.2420_IVS20-8 del TCTGAAACAins CGAAAG) was identified in FAMILY-1. A heterozygous FBN1 mutation in exon 14(c.1633 C>T, p.R545 C) was identified in FAMILY-2. Each mutation cosegregated with the affected individuals in the family and did not exist in unaffected family members and 200 unrelated normal controls.CONCLUSION: The insertion-deletion mutation(c.2420 IVS20-8 del TCTGAAACA ins CGAAAG) in the FBN1 gene is first identified in isolated EL. The mutation(c.1633 C>T) in the FBN1 gene was a known mutation in EL patient. The variable phenotypes among the patients expand the phenotypic spectrum of EL in a different ethnic background.

LRP1 knockdown agravates lipopolysaccharide stimulated microglial and astrocytic neuroinflammatory responses by modulating TLR4/NF-κB/MAPKs signaling pathways

Neuroinflammation is an important pathological feature and an early event in the pathogenesis of Alzheimer's disease(AD),which is characterized by activation of microglia and astrocytes.Low-density lipoprotein receptor related protein 1(LRP1)is an endocytic receptor that is abundantly expressed in neurons,microglia,and astrocytes,and plays a critical role in AD pathogenesis.There is increasing evidence to show that LRP1 regulates inflammatory responses by modulating the release of pro-inflammatory cytokines and phagocytosis.

The role of neuronal Fc-epsilon receptor 1 in itch of allergic conjunctivitis rat model

Itch has been an increasingly concerned clinical problem as it has caused needless suffering of people's life.However,current therapeutics targeting the immune system sometimes fail to achieve satisfactory results.We hereby explored the role of neuronal Fc-epsilon receptor I(FceRI)in itch of allergic conjunctivitis rat model.After establishment of allergic conjunctivitis model in experimental groups of rats by ovalbumin as allergen,we observed scratch behavior of both experimental groups and control groups,with scratching eyes by hind lim bs regarded as itch-related behavior.The allergic wild type rats showed significantly elevation of scratch behavior compared to the naive rats,as well as the allergic rats with neuron conditional knockout of FceRI.Meanwhile,we detected the expression of FceRI and pSyk,which is the main downstream molecule of FceRI,in neurons in the trigeminal ganglion(TG)by Western blotting and immunohistochemistry,which showed up-regulation in allergic rats.