Exosomes derived from human induced pluripotent stem cell-derived neural progenitor cells protect neuronal function under ischemic conditions

Compared with other stem cells,human induced pluripotent stem cells-derived neural progenitor cells(iPSC-NPCs)are more similar to cortical neurons in morphology and immunohistochemistry.Thus,they have greater potential for promoting the survival and growth of neurons and alleviating the proliferation of astrocytes.Transplantation of stem cell exosomes and stem cells themselves have both been shown to effectively repair nerve injury.However,there is no study on the protective effects of exosomes derived from iPSC-NPCs on oxygen and glucose deprived neurons.In this study,we established an oxygen-glucose deprivation model in embryonic cortical neurons of the rat by culturing the neurons in an atmosphere of 95%N2 and 5%CO2 for 1 hour and then treated them with iPSC-NPC-derived exosomes for 30 minutes.Our results showed that iPSC-NPC-derived exosomes increased the survival of oxygen-and glucose-deprived neurons and the level of brain-derived neurotrophic factor in the culture medium.Additionally,it attenuated oxygen and glucose deprivation-induced changes in the expression of the PTEN/AKT signaling pathway as well as synaptic plasticity-related proteins in the neurons.Further,it increased the length of the longest neurite in the oxygen-and glucose-deprived neurons.These findings validate the hypothesis that exosomes from iPSCNPCs exhibit a neuroprotective effect on oxygen-and glucose-deprived neurons by regulating the PTEN/AKT signaling pathway and neurite outgrowth.This study was approved by the Animal Ethics Committee of Sir Run Run Shaw Hospital,School of Medicine,Zhejiang University,China(approval No.SRRSH20191010)on October 10,2019.

Influence of injection of Chinese botulinum toxin type A on the histomorphology and myosin heavy chain composition of rat gastrocnemius muscles

Background and objective:Botulinum toxin type A(BoNT/A)is a metalloprotease that blocks synaptic transmission via the cleavage of a synaptosomal-associated protein of 25 kDa(SNAP-25).It has gained widespread use as a treatment for cerebral palsy and skeletal muscle hypertrophy.In China,Chinese botulinum toxin type A(CBTX-A),a type of BoNT/A,is in widespread clinical use.However,the changes in the morphological and biochemical properties of treated muscles and in remote muscles from the CBTX-A injection site are relatively unknown.Therefore,we investigated the changes in histomorphology and myosin heavy chain(MyHC)isoform composition and distribution in rat gastrocnemius muscles after intramuscular injection of CBTX-A.Methods:The weakness of the injected muscles was assessed periodically to identify their functional deficiency.Muscle slices were stained with hematoxylin-eosin(HE)and adenosine triphosphatase(ATPase).MyHC isoform composition was analyzed by sodium dodecyl sulfatepolyacrylamide gel electrophoresis(SDS-PAGE)to uncover changes in morphological and biochemical properties.Results:Our findings demonstrate that following injection of CBTX-A 5 U into rat gastrocnemius muscles,shifts in MyHC isoform composition emerged on the third day after injection and peaked in the fourth week.The composition remained distinctly different from that of the control group after the twelfth week.More specifically,there was a decrease in the proportion of the type IIb isoform and an increase in the proportions of type IIx,type IIa,and type I isoforms.Conclusions:Data revealed that CBTX-A led to a shift in MyHC composition towards slower isoforms and that the MyHC composition remained far from normal six months after a single injection.However,no noticeable remote muscle weakness was induced.

影响自发性颅内低压患者的脑脊液开放压的潜在因素（英文）

目的:评估正常脑脊液开放压在自发性颅内低压(SIH)患者中所占的比例,并初步探讨SIH患者的脑脊液开放压的影响因素。创新点:通过大样本容量的病例证实了正常脑脊液开放压在SIH患者中占较高比例,并进一步得出体重指数和症状持续时间与脑脊液开放压存在显著相关性。方法:回顾了206例在我院确诊的SIH患者,收集其人口学信息、体重指数、症状持续时间、影像检查结果等资料。通过单变量分析和多变量分析识别影响脑脊液开放压的潜在因素。结论:本研究进一步证实正常脑脊液开放压在SIH患者中并不少见,特别是那些肥胖和症状持续时间长的患者。除了体重指数和症状持续时间,仍然存在其他未识别的因素影响SIH患者的脑脊液开放压大小。