To investigate the effects of L-Tetrahydropalmatine (L-THP ) on neuron apoptosis during acute cerebral ischemia-reperfusion of rats and explore the effects of heat shock protein (HSP) on neuron apoptosis, Wistar rats ...To investigate the effects of L-Tetrahydropalmatine (L-THP ) on neuron apoptosis during acute cerebral ischemia-reperfusion of rats and explore the effects of heat shock protein (HSP) on neuron apoptosis, Wistar rats were randomly divided into 3 groups: normal group, ischemia- reperfusion group and treatment group. The condition of neuron apoptosis, the survival state of neuron, pathological changes under an electron microscope and the number of HSP70 positive cells were measured in all groups. Results showed that the apoptosis neuron number was increased obviously at the 24th h during reperfusion and was further increased at the 48th h, the 72th h. While the number of survival neurons was decreased gradually with the prolongation of reperfusion time. Treatment with L-THP could decrease the apoptosis neuron number but increase the survival neuron number and the HSP70 positive cell number. Our study suggested that L-THP could decrease apoptosis and necrosis of neuron, up-regulate the expression of HSP70 and protect the cerebral ischemic injury.展开更多
To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viabi...To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (△Ψm) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn’t completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can’t completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.展开更多
BACKGROUND: Aggregation of β-amyloid peptide (Aβ), excitatory intoxication, oxidation injury and inflammation reaction are generally regarded as the main pathogenesis for Alzheimer disease (AD). (–) clausenamide is...BACKGROUND: Aggregation of β-amyloid peptide (Aβ), excitatory intoxication, oxidation injury and inflammation reaction are generally regarded as the main pathogenesis for Alzheimer disease (AD). (–) clausenamide is characterized by promoting intelligent development, resisting oxidation, cleaning free radicals, resisting Aβ neurotoxicity and nerve cell apoptosis, inhibiting over phosphorylation of tau protein, and improving central cholinergic system. However, whether (– ) clausenamide has an effect on hippocampal neuron apoptosis or not need further study. OBJECTIVE: To observe the effect of (–) clausenamide on survival rate of hippocampal neurons due to sodium nitroprusside (SNP) and analyze the possible pathways. DESIGN: Contrast observation. SETTING: Institute of Biochemistry and Molecular Biology, Guangdong Medical College. MATERIALS: A total of 12 male SD rats of 24 hours old were provided by the Experimental Animal Center of Guangdong Medical College. The primer was synthesized by Beijing Huada Genetic Engineering Company and (–) clausenamide (99.6%) was provided by Pharmacological Department of Chinese Academy of Medical Sciences. SNP was provided by Sigma Company. METHODS: Bilateral hippocampus was collected from newborn rats to establish single cell suspension. On the 12th day, hippocampal neurons were pretreated with 0.2, 0.4, 0.8 and 1.6 μmol/L (–) clausenamide for 6 hours; the culture medium was gotten rid of and neurons were washed with non-serum DMEM solution for three times. In addition, non-serum DMEM solution was added with the above mentioned volume of (–) clausenamide and 50 μmol/L SNP to culture neurons for 24 hours and the collected cells were prepared for the experiment. Neurons were equally divided into control group (culture medium control), model group (SNP treatment) and experimental group [(–) clausenamide + SNP]. Experiment of each group was done for three times at least. Survival rate of cells was measured with MTT chromatometry; levels of mRNA of hippocampal neuron bcl-2 and bax gene were detected with reverse transcription polymerase chain reaction (RT-PCR); expression of hippocampal neuron Bcl-2 and Bax protein was measured with Western blot technique. MAIN OUTCOME MEASURES: ① Effect of (–) clausenamide on survival rate of SNP-induced hippocampal neuron apoptosis; ② bcl-2 and bax mRNA and protein expression of hippocampal neurons. RESULTS: ① Survival rate of hippocampal neurons: Survival rate of hippocampal neurons affected by 0.4–1.6 μmol/L (–) clausenamide was higher in the experimental group than the model group (P < 0.01), and the survival rate was increased with the larger volume of (–) clausenamide. Survival rate was the highest when hippocampal neurons were induced by 1.6 μmol/L, and it had obvious dosage dependence (P < 0.01). ② Expression of bcl-2 and bax mRNA: Hippocampal neurons were pretreated with 0.2–1.6 μmol/L (–) clausenamide for 6 hours in the experimental group and strap of PCR product of bcl-2 gene was brightened gradually. This suggested that, with the increase of concentration, expression of bcl-2 mRNA was increased simultaneously. However, when strap of PCR product of bax gene was darkened, expression of bax was decreased with the increase of concentration. ③ Expression of Bcl-2 and Bax protein: Hippocampal neurons were pretreated with 0.2–1.6 μmol/L (–) clausenamide for 6 hours in the experimental group and strap of PCR product of Bcl-2 protein was thickened gradually. This suggested that, with the increase of concentration, expression of Bcl-2 protein was increased simultaneously. However, when strap of PCR product of Bax protein was thinned, expression of Bax protein was decreased with the increase of concentration. CONCLUSION: (–) clausenamide can resist neurotoxic effect of SNP through dosage dependence, and the mechanism may be related to promoting expression of anti-apoptotic bcl-2 gene and inhibiting expression ofpro-apoptotic bax gene.展开更多
Previous studies have shown that 5-hydroxymethylfurfural,a compound extracted from wineprocessed Fructus corni,has a protective effect on hippocampal neurons.The present study was designed to explore the related mecha...Previous studies have shown that 5-hydroxymethylfurfural,a compound extracted from wineprocessed Fructus corni,has a protective effect on hippocampal neurons.The present study was designed to explore the related mechanisms.Our study revealed that high and medium doses(10,1μmol/L)of 5-hydroxymethylfurfural could improve the morphology of H2O2-treated rat hippocampal neurons as revealed by inverted phase-contrast microscopy and transmission electron microscopy.MTT results showed that incubation with high and medium doses of 5-hydroxymethylfurfural caused a significant increase in the viability of neuronal cells injured by H2O2.Flow cytometry assays confirmed that H2O2could induce cell apoptosis,while high and medium doses of5-hydroxymethylfurfural had a visible protective effect on apoptotic rat hippocampal neurons.Real-time PCR and western blot analysis showed that high and medium doses of5-hydroxymethylfurfural prevented H2O2-induced up-regulation of p53,Bax and caspase-3 and antagonized the down-regulation of Bcl-2 induced by H2O2treatment.These results suggested that5-hydroxymethylfurfural could inhibit apoptosis of cultured rat hippocampal neurons injured by H2O2via increase in Bcl-2 levels and decrease in p53,Bax and caspase-3 protein expression levels.展开更多
Objective: To explore the expression of nuclear factor-kappa B (NF-κB) in Schwann cells (SCs) and its effect on motor neuron apoptosis in spinal cord following sciatic nerves injury in adult rats. Methods: Thirty-six...Objective: To explore the expression of nuclear factor-kappa B (NF-κB) in Schwann cells (SCs) and its effect on motor neuron apoptosis in spinal cord following sciatic nerves injury in adult rats. Methods: Thirty-six adult Sprague-Dawley (SD) rats were divided randomly into normal control group (n=6), and sciatic nerves crushing group (n=30). and the later was further equally randomized into 5 subgroups: 1. 3. 7. 11. and 21 d post-injury groups. The expression of NF-κB of normal and injured nerves were examined by immunohistochemistry staining, and the apoptosis of motor neurons in spinal cord of lumbar 4 to lumbar 6 (L4-L6) was investigated by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNED assay. Both were quantitated by image analysis. Results: In crushing group, except 21 d post-injury group, the expression of NF-κB was markedly higher than that in the normal control group (P<0. 05,P<0. 01). At 1 d after sciatic nerves crushing, the expression of NF-κB was obviously up-regulated, reached peak at 3 d. and recovered at 21 d. The same trend was observed in the time-course on motor neuron apoptosis after sciatic nerves injury. Correlation analyses revealed that motor neuron apoptosis was significantly and positively correlated with the expression of NF-κB following sciatic nerves injury (r=0. 976 0,P<0. 01). Conclusion: After injury of sciatic nerves, the presence and up-regulation of NF-κB in SCs may be involved in motor neuron apoptosis in L4-L6 spinal cord.展开更多
Objective:To study the protective effect of dexmedetomidine on the propofol-induced cognitive dysfunction and neuron apoptosis in rats.Methods: SD rats were selected as the experimental animals and randomly divided in...Objective:To study the protective effect of dexmedetomidine on the propofol-induced cognitive dysfunction and neuron apoptosis in rats.Methods: SD rats were selected as the experimental animals and randomly divided into control group, propofol group and Dex group, propofol group and Dex group were established into propofol-induced cognitive dysfunction models by intraperitoneal injection of propofol, and Dex were given dexmedetomidine intervention on the basis of model establishment. The cognitive behavioral indicators were measured 1 d, 3 d and 5 d after model establishment;the contents of nerve marker molecules as well as inflammatory and oxidative stress response molecules in brain tissue of the hippocampus were measured at 5 d after model establishment.Results: 1 d, 3 d and 5 d after model establishment, the escape latency of propofol group were significantly longer than those of control group while the frequency of original platform crossing were significantly less than those of control group, and the escape latency of Dex group were significantly shorter than those of propofol group while the frequency of original platform crossing were significantly more than those of propofol group;5 d after model establishment, BDNF, SYN1, GPx and SOD contents in brain tissue of propofol group were significantly lower than those of control group while Nogo-A, Aβ, NF-kB p65, P2X7, TNFα, MCP1, ROS, p47PHOX and MDA contents were significantly higher than those of control group;BDNF, SYN1, GPx and SOD contents in brain tissue of Dex group were significantly higher than those of propofol group while Nogo-A, Aβ, NF-kB p65, P2X7, TNFα, MCP1, ROS, p47PHOX and MDA contents were significantly lower than those propofol group.Conclusion: Dexmedetomidine can reduce the cognitive dysfunction induced by propofol and inhibit the apoptosis induced by inflammatory response and oxidative stress response.展开更多
BACKGROUND:Interleukin-2 (IL-2) may influence the growth and survival of nerve cells following spi-nal cord injury and resuscitate the proliferation and maturation of oligodendrocytes. OBJECTIVE: To observe the effect...BACKGROUND:Interleukin-2 (IL-2) may influence the growth and survival of nerve cells following spi-nal cord injury and resuscitate the proliferation and maturation of oligodendrocytes. OBJECTIVE: To observe the effect of IL-2 on neuronal apoptosis of neurogliocytes at different times fol-lowing acute spinal cord injury in rats. DESIGN,TIME AND SETTING: A randomized grouping trial based on cellular morphology was per-formed at the Institute of Traumatic Orthopedics of Shandong Province between October 2004 and January 2006. MATERIALS: A total of 72 adult,male,Sprague Dawley rats were included in this study and were divided into a control group and an IL-2 group. The Bcl-2 monoclonal antibody and TUNEL kit were purchased from Wunan Boster Biological Technology Corporation. METHODS: Spinal cord injury was induced in all the rats by dropping a weight from a height of 25 cm onto the exposed spinal cord at vertebral levels T7-11,thus producing a mild lesion. Immediately following the modeling,the rats were injected with daily IL-2 (10 μL) intramuscularly (the IL-2 group). Other rats re-ceived an injection of physiological saline 0.5 mL/d (the control group). MAIN OUTCOME MEASURES: Bcl-2 immunohistochemistry was applied to detect the Bcl-protein and positive cell expression. The TUNEL method was used to count the number of apoptotic cells. RESULTS: The expression level of Bcl-2 proteins increased significantly in spinal cord tissues during the first day after acute spinal cord injury,reaching a peak on days 3 and days 8 in the control and IL-2 groups,respectively. They were more prevalent in neurogliocytes than in neurocytes,and then began to decrease on day 14. From then until day 21,less expression was detected (P < 0.05). In the control group,many apoptotic cells existed after 24 hours,and most of them were gliocytes; apoptotic cells reached a peak after 3-8 days. They then decreased gradually until day 21,when a small number of cells were still available. In the IL-2 group,the number of positive cells was significantly lower than in the control group (P < 0.05). CONCLUSION: The expression of Bcl-2 and the number of apoptotic cells in neurogliocytes undergo simi-lar changes with time after acute spinal cord injury. IL-2 may upregulate the expression of Bcl-2 proteins and decrease cell apoptosis in spinal cord tissue.展开更多
Rat models of acute spinal cord injury and sciatic nerve injury were established.Apelin expression in spinal cord tissue was determined.In normal rat spinal cords,apelin expression was visible;however,2 hours post spi...Rat models of acute spinal cord injury and sciatic nerve injury were established.Apelin expression in spinal cord tissue was determined.In normal rat spinal cords,apelin expression was visible;however,2 hours post spinal cord injury,apelin expression peaked.Apelin expression increased 1 day post ligation of the sciatic nerve compared with normal rat spinal cords,and peaked at 3 days.Apelin expression was greater in the posterior horn compared with the anterior horn at each time point when compared with the normal group.The onset of neuronal apoptosis was significantly delayed following injection of apelin protein at the stump of the sciatic nerve,and the number of apoptotic cells after injury was reduced when compared with normal spinal cords.Our results indicate that apelin is expressed in the normal spinal cord and central nervous system after peripheral nerve injury.Apelin protein can reduce motor neuron apoptosis in the spinal cord anterior horn and delay the onset of apoptosis.展开更多
This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase...This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase-3, which are retinal apoptosis-associated factors in rats with diabetes mellitus induced by continuous intraperitoneal injection of streptozotocin. The results showed that Purendan superfine powder could upregulate the expression of bcl-2 protein and mRNA, and downregulate the expression of bax and caspase-3 in the retina of diabetes mellitus rats. In addition, Purendan superfine powder was shown to reduce the number of apoptotic neurons. Our experimental findings indicate that Purendan superfine powder can inhibit neuronal apoptosis in the retina of diabetes mellitus rats and has protective effects on diabetic retinopathy.展开更多
Wistar rats were intragastrically perfused with Chinese medicines used for tonifying the kidney.These included 0.180 g/mL of Herba Epimedii(Epimedium), Semen Cuscutae(Dodder Seed), or Herba Cistanches(Desertliving Cis...Wistar rats were intragastrically perfused with Chinese medicines used for tonifying the kidney.These included 0.180 g/mL of Herba Epimedii(Epimedium), Semen Cuscutae(Dodder Seed), or Herba Cistanches(Desertliving Cistanche), 0.04 mg/mL monoamine oxidase-B inhibitor selegiline,or distilled water for 14 consecutive days to prepare drug-containing serum or blank serum.MES23.5 cells in the logarithmic phase were cultured in media supplemented with 15%drug-containing serum for 24 hours, followed by incubation in culture solution containing 100 μmol/L H2O2for 3 hours. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) and flow cytometry results showed that all drug-containing serums improved the survival rate of H2O2-injured MES23.5 cells, inhibited pro-apoptotic FasL and caspase-3 expression, promoted anti-apoptotic Bcl-2 expression. However, drug-containing serums had little influence on Fas expression in H2O2-injured MES23.5 cells. Enzyme-linked immunosorbent assay results showed that serum containing Herba Cistanches or Herba Epimedii increased the expression of nerve growth factor,brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor in injured MES23.5cells; serum containing Semen Cuscutae only increased brain-derived neurotrophic factor expression; while expression of the above neurotrophic factors remained the same in cells treated with serum containing selegiline. These findings indicate that Chinese medicines used to tonify the kidney can protect nerve cells by regulating the expression of apoptosis-related factors and neurotrophic factors in MES23.5 cells.展开更多
Subarachnoid hemorrhage(SAH)is a dominant cause of death and disability wo rldwide.A sharp increase in intracranial pressure after SAH leads to a reduction in cerebral perfusion and insufficient blood supply for neuro...Subarachnoid hemorrhage(SAH)is a dominant cause of death and disability wo rldwide.A sharp increase in intracranial pressure after SAH leads to a reduction in cerebral perfusion and insufficient blood supply for neuro ns,which subsequently promotes a series of pathophysiological responses leading to neuronal death.Many previous experimental studies have reported that excitotoxicity,mitochondrial death pathways,the release of free radicals,protein misfolding,apoptosis,nec rosis,autophagy,and inflammation are involved solely or in combination in this disorder.Among them,irreversible neuronal apoptosis plays a key role in both short-and long-term prognoses after SAH.Neuronal apoptosis occurs through multiple pathways including extrinsic,mitochondrial,endoplasmic reticulum,p53 and oxidative stress.Meanwhile,a large number of blood contents enter the subarachnoid space after SAH,and the secondary metabolites,including oxygenated hemoglo bin and heme,further aggravate the destruction of the blood-brain barrier and vasogenic and cytotoxic brain edema,causing early brain injury and delayed cerebral ischemia,and ultimately increasing neuronal apoptosis.Even there is no clear and effective therapeutic strategy for SAH thus far,but by understanding apoptosis,we might excavate new ideas and approaches,as targeting the upstream and downstream molecules of apoptosis-related pathways shows promise in the treatment of SAH.In this review,we summarize the existing evidence on molecules and related drugs or molecules involved in the apoptotic pathway after SAH,which provides a possible target or new strategy for the treatment of SAH.展开更多
Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia.However,whether there is a synergistic effect between the two remains unclea...Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia.However,whether there is a synergistic effect between the two remains unclear.In this study,we established rat models of ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours.Rat models were perfused with bone marrow mesenchymal stem cell-derived exosomes(MSC-exos)via the tail vein and underwent 14 successive days of treadmill exercise.Neurological assessment,histopathology,and immunohistochemistry results revealed decreased neuronal apoptosis and cerebral infarct volume,evident synaptic formation and axonal regeneration,and remarkably recovered neurological function in rats subjected to treadmill exercise and MSC-exos treatment.These effects were superior to those in rats subjected to treadmill exercise or MSC-exos treatment alone.Mechanistically,further investigation revealed that the activation of JNK1/c-Jun signaling pathways regulated neuronal apoptosis and synaptic-axonal remodeling.These findings suggest that treadmill exercise may exhibit a synergistic effect with MSC-exos treatment,which may be related to activation of the JNK1/c-Jun signaling pathway.This study provides novel theoretical evidence for the clinical application of treadmill exercise combined with MSC-exos treatment for ischemic cerebrovascular disease.展开更多
Circular RNAs can regulate the development and progression of ischemic cerebral disease.However,it remains unclear whether they play a role in acute ischemic stroke.To investigate the role of the circular RNA Rap1b(ci...Circular RNAs can regulate the development and progression of ischemic cerebral disease.However,it remains unclear whether they play a role in acute ischemic stroke.To investigate the role of the circular RNA Rap1b(circRap1b)in acute ischemic stroke,in this study we established an in vitro model of acute ischemia and hypoxia by subjecting HT22 cells to oxygen and glucose deprivation and a mouse model of acute ischemia and hypoxia by occluding the right carotid artery.We found that circRap1b expression was remarkably down-regulated in the hippocampal tissue of the mouse model and in the HT22 cell model.In addition,Hoxa5 expression was strongly up-regulated in response to circRap1b overexpression.Hoxa5 expression was low in the hippocampus of a mouse model of acute ischemia and in HT22-AIS cells,and inhibited HT22-AIS cell apoptosis.Importantly,we found that circRap1b promoted Hoxa5 transcription by recruiting the acetyltransferase Kat7 to induce H3K14ac modification in the Hoxa5 promoter region.Hoxa5 regulated neuronal apoptosis by activating transcription of Fam3a,a neuronal apoptosis-related protein.These results suggest that circRap1b regulates Hoxa5 transcription and expression,and subsequently Fam3a expression,ultimately inhibiting cell apoptosis.Lastly,we explored the potential clinical relevance of circRap1b and Hoxa5 in vivo.Taken together,these findings demonstrate the mechanism by which circRap1b inhibits neuronal apoptosis in acute ischemic stroke.展开更多
Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide...Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold,that is,has an anticonvulsant effect.However,the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear.In this study,we performed RNA sequencing,functional enrichment analysis,and weighted gene coexpression network analysis of the hippocampus of tremor rats,a rat model of genetic epilepsy.We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity.In addition,we used a pilocarpine-induced N2a cell model to mimic epileptic injury.After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole,changes in malondialdehyde,lactate dehydrogenase and superoxide dismutase,which are associated with oxidative stress,were reversed,and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine.Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells.Furthermore,7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3,gasdermin-D,interleukin-1βand interleukin-18.This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death.Taken together,our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells,and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.展开更多
Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a gua...Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.展开更多
We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repet...We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.展开更多
Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are ...Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are lacking.Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease.This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques,and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI.We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations.Finally,we identify the challenges and possible solutions for spinal cord neuron imaging.展开更多
Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to t...Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to the destabilization of microtubules, is central to the pathogenesis of Alzheimer’s disease. This is accompanied by morphological defects across the somatodendritic compartment, axon, and synapse. However, knowledge of what occurs to the microtubule cytoskeleton and morphology of the neuron during physiological aging is comparatively poor. Several recent studies have suggested that there is an age-related increase in the phosphorylation of the key microtubule stabilizing protein tau, a modification, which is known to destabilize the cytoskeleton in Alzheimer’s disease. This indicates that the cytoskeleton and potentially other neuronal structures reliant on the cytoskeleton become functionally compromised during normal physiological aging. The current literature shows age-related reductions in synaptic spine density and shifts in synaptic spine conformation which might explain age-related synaptic functional deficits. However, knowledge of what occurs to the microtubular and actin cytoskeleton, with increasing age is extremely limited. When considering the somatodendritic compartment, a regression in dendrites and loss of dendritic length and volume is reported whilst a reduction in soma volume/size is often seen. However, research into cytoskeletal change is limited to a handful of studies demonstrating reductions in and mislocalizations of microtubule-associated proteins with just one study directly exploring the integrity of the microtubules. In the axon, an increase in axonal diameter and age-related appearance of swellings is reported but like the dendrites, just one study investigates the microtubules directly with others reporting loss or mislocalization of microtubule-associated proteins. Though these are the general trends reported, there are clear disparities between model organisms and brain regions that are worthy of further investigation. Additionally, longitudinal studies of neuronal/cytoskeletal aging should also investigate whether these age-related changes contribute not just to vulnerability to disease but also to the decline in nervous system function and behavioral output that all organisms experience. This will highlight the utility, if any, of cytoskeletal fortification for the promotion of healthy neuronal aging and potential protection against age-related neurodegenerative disease. This review seeks to summarize what is currently known about the physiological aging of the neuron and microtubular cytoskeleton in the hope of uncovering mechanisms underpinning age-related risk to disease.展开更多
Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogr...Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogramming is a promising strategy to convert glial scars to neural tissue.However,previous studies have reported inconsistent results.In this study,an AAV9P1 vector incorporating an astrocyte-targeting P1 peptide and glial fibrillary acidic protein promoter was used to achieve dual-targeting of astrocytes and the glial scar while minimizing off-target effects.The results demonstrate that AAV9P1 provides high selectivity of astrocytes and reactive astrocytes.Moreover,neuronal reprogramming was induced by downregulating the polypyrimidine tract-binding protein 1 gene via systemic administration of AAV9P1 in a mouse model of traumatic brain injury.In summary,this approach provides an improved gene delivery vehicle to study neuronal programming and evidence of its applications for traumatic brain injury.展开更多
文摘To investigate the effects of L-Tetrahydropalmatine (L-THP ) on neuron apoptosis during acute cerebral ischemia-reperfusion of rats and explore the effects of heat shock protein (HSP) on neuron apoptosis, Wistar rats were randomly divided into 3 groups: normal group, ischemia- reperfusion group and treatment group. The condition of neuron apoptosis, the survival state of neuron, pathological changes under an electron microscope and the number of HSP70 positive cells were measured in all groups. Results showed that the apoptosis neuron number was increased obviously at the 24th h during reperfusion and was further increased at the 48th h, the 72th h. While the number of survival neurons was decreased gradually with the prolongation of reperfusion time. Treatment with L-THP could decrease the apoptosis neuron number but increase the survival neuron number and the HSP70 positive cell number. Our study suggested that L-THP could decrease apoptosis and necrosis of neuron, up-regulate the expression of HSP70 and protect the cerebral ischemic injury.
基金ThisprojectwassupportedbyagrantfromNaturalScienceFoundationofHygienicCommitteeofHubeiProvince (No .WJ0 1 5 1 0 ) .
文摘To investigate the role of mitochondria in neuronal apoptosis, ischemia-reperfusion mediated neuronal cell injury model was established by depriving of glucose, serum and oxygen in media. DNA fragmentation, cell viability, cytochrome C releasing, caspase3 activity and mitochondrial transmembrane potential were observed after N2a cells suffered the insults. The results showed that N2a cells in ischemic territory exhibited survival damage, classical cell apoptosis change, DNA ladder and activation of caspase3. Apoptosis-related alterations in mitochondrial functions, including release of cytochrome C and depression of mitochondrial transmembrane potential (△Ψm) were testified in N2a cells after mimic ischemia-reperfusion. Moreover, activation of caspase3 occurred following the release of cytochrome C. However, the inhibitor of caspase3, Ac-DEVD-CHO, couldn’t completely rescue N2a cells from apoptosis. Administration of cyclosporine A, an inhibitor of mitochondria permeability transition pore only partly inhibited caspase3 activity and reduced DNA damage. Interestingly, treatment of Z-IETD-FMK, an inhibitor of caspase8 could completely reverse DNA fragmentation, but can’t completely inhibit caspase3 activity. It was concluded that there were caspase3 dependent and independent cellular apoptosis pathways in N2a cells suffering ischemia-reperfusion insults. Mitochondria dysfunction may early trigger apoptosis and amplify apoptosis signal.
文摘BACKGROUND: Aggregation of β-amyloid peptide (Aβ), excitatory intoxication, oxidation injury and inflammation reaction are generally regarded as the main pathogenesis for Alzheimer disease (AD). (–) clausenamide is characterized by promoting intelligent development, resisting oxidation, cleaning free radicals, resisting Aβ neurotoxicity and nerve cell apoptosis, inhibiting over phosphorylation of tau protein, and improving central cholinergic system. However, whether (– ) clausenamide has an effect on hippocampal neuron apoptosis or not need further study. OBJECTIVE: To observe the effect of (–) clausenamide on survival rate of hippocampal neurons due to sodium nitroprusside (SNP) and analyze the possible pathways. DESIGN: Contrast observation. SETTING: Institute of Biochemistry and Molecular Biology, Guangdong Medical College. MATERIALS: A total of 12 male SD rats of 24 hours old were provided by the Experimental Animal Center of Guangdong Medical College. The primer was synthesized by Beijing Huada Genetic Engineering Company and (–) clausenamide (99.6%) was provided by Pharmacological Department of Chinese Academy of Medical Sciences. SNP was provided by Sigma Company. METHODS: Bilateral hippocampus was collected from newborn rats to establish single cell suspension. On the 12th day, hippocampal neurons were pretreated with 0.2, 0.4, 0.8 and 1.6 μmol/L (–) clausenamide for 6 hours; the culture medium was gotten rid of and neurons were washed with non-serum DMEM solution for three times. In addition, non-serum DMEM solution was added with the above mentioned volume of (–) clausenamide and 50 μmol/L SNP to culture neurons for 24 hours and the collected cells were prepared for the experiment. Neurons were equally divided into control group (culture medium control), model group (SNP treatment) and experimental group [(–) clausenamide + SNP]. Experiment of each group was done for three times at least. Survival rate of cells was measured with MTT chromatometry; levels of mRNA of hippocampal neuron bcl-2 and bax gene were detected with reverse transcription polymerase chain reaction (RT-PCR); expression of hippocampal neuron Bcl-2 and Bax protein was measured with Western blot technique. MAIN OUTCOME MEASURES: ① Effect of (–) clausenamide on survival rate of SNP-induced hippocampal neuron apoptosis; ② bcl-2 and bax mRNA and protein expression of hippocampal neurons. RESULTS: ① Survival rate of hippocampal neurons: Survival rate of hippocampal neurons affected by 0.4–1.6 μmol/L (–) clausenamide was higher in the experimental group than the model group (P < 0.01), and the survival rate was increased with the larger volume of (–) clausenamide. Survival rate was the highest when hippocampal neurons were induced by 1.6 μmol/L, and it had obvious dosage dependence (P < 0.01). ② Expression of bcl-2 and bax mRNA: Hippocampal neurons were pretreated with 0.2–1.6 μmol/L (–) clausenamide for 6 hours in the experimental group and strap of PCR product of bcl-2 gene was brightened gradually. This suggested that, with the increase of concentration, expression of bcl-2 mRNA was increased simultaneously. However, when strap of PCR product of bax gene was darkened, expression of bax was decreased with the increase of concentration. ③ Expression of Bcl-2 and Bax protein: Hippocampal neurons were pretreated with 0.2–1.6 μmol/L (–) clausenamide for 6 hours in the experimental group and strap of PCR product of Bcl-2 protein was thickened gradually. This suggested that, with the increase of concentration, expression of Bcl-2 protein was increased simultaneously. However, when strap of PCR product of Bax protein was thinned, expression of Bax protein was decreased with the increase of concentration. CONCLUSION: (–) clausenamide can resist neurotoxic effect of SNP through dosage dependence, and the mechanism may be related to promoting expression of anti-apoptotic bcl-2 gene and inhibiting expression ofpro-apoptotic bax gene.
基金financially supported by the National Natural Science Foundation of China,No.30772851a grant from the Six Talents Peaks Program of Jiangsu Province,Chinaa grant from the Priority Academic Program Development of Jiangsu Higher Education Institutions,PAPD(Traditional Chinese medicine combined with Western Medicine
文摘Previous studies have shown that 5-hydroxymethylfurfural,a compound extracted from wineprocessed Fructus corni,has a protective effect on hippocampal neurons.The present study was designed to explore the related mechanisms.Our study revealed that high and medium doses(10,1μmol/L)of 5-hydroxymethylfurfural could improve the morphology of H2O2-treated rat hippocampal neurons as revealed by inverted phase-contrast microscopy and transmission electron microscopy.MTT results showed that incubation with high and medium doses of 5-hydroxymethylfurfural caused a significant increase in the viability of neuronal cells injured by H2O2.Flow cytometry assays confirmed that H2O2could induce cell apoptosis,while high and medium doses of5-hydroxymethylfurfural had a visible protective effect on apoptotic rat hippocampal neurons.Real-time PCR and western blot analysis showed that high and medium doses of5-hydroxymethylfurfural prevented H2O2-induced up-regulation of p53,Bax and caspase-3 and antagonized the down-regulation of Bcl-2 induced by H2O2treatment.These results suggested that5-hydroxymethylfurfural could inhibit apoptosis of cultured rat hippocampal neurons injured by H2O2via increase in Bcl-2 levels and decrease in p53,Bax and caspase-3 protein expression levels.
基金Supported by the National Natural Science Foundation of China (No. 30600665)the Opening Project Foundation of State Key Laboratory of Trauma. Burns and Combined Injury (No. 2006A-3)the Youth Scientific Research Foundation of Third Military Medical University (No.06XG048)
文摘Objective: To explore the expression of nuclear factor-kappa B (NF-κB) in Schwann cells (SCs) and its effect on motor neuron apoptosis in spinal cord following sciatic nerves injury in adult rats. Methods: Thirty-six adult Sprague-Dawley (SD) rats were divided randomly into normal control group (n=6), and sciatic nerves crushing group (n=30). and the later was further equally randomized into 5 subgroups: 1. 3. 7. 11. and 21 d post-injury groups. The expression of NF-κB of normal and injured nerves were examined by immunohistochemistry staining, and the apoptosis of motor neurons in spinal cord of lumbar 4 to lumbar 6 (L4-L6) was investigated by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNED assay. Both were quantitated by image analysis. Results: In crushing group, except 21 d post-injury group, the expression of NF-κB was markedly higher than that in the normal control group (P<0. 05,P<0. 01). At 1 d after sciatic nerves crushing, the expression of NF-κB was obviously up-regulated, reached peak at 3 d. and recovered at 21 d. The same trend was observed in the time-course on motor neuron apoptosis after sciatic nerves injury. Correlation analyses revealed that motor neuron apoptosis was significantly and positively correlated with the expression of NF-κB following sciatic nerves injury (r=0. 976 0,P<0. 01). Conclusion: After injury of sciatic nerves, the presence and up-regulation of NF-κB in SCs may be involved in motor neuron apoptosis in L4-L6 spinal cord.
文摘Objective:To study the protective effect of dexmedetomidine on the propofol-induced cognitive dysfunction and neuron apoptosis in rats.Methods: SD rats were selected as the experimental animals and randomly divided into control group, propofol group and Dex group, propofol group and Dex group were established into propofol-induced cognitive dysfunction models by intraperitoneal injection of propofol, and Dex were given dexmedetomidine intervention on the basis of model establishment. The cognitive behavioral indicators were measured 1 d, 3 d and 5 d after model establishment;the contents of nerve marker molecules as well as inflammatory and oxidative stress response molecules in brain tissue of the hippocampus were measured at 5 d after model establishment.Results: 1 d, 3 d and 5 d after model establishment, the escape latency of propofol group were significantly longer than those of control group while the frequency of original platform crossing were significantly less than those of control group, and the escape latency of Dex group were significantly shorter than those of propofol group while the frequency of original platform crossing were significantly more than those of propofol group;5 d after model establishment, BDNF, SYN1, GPx and SOD contents in brain tissue of propofol group were significantly lower than those of control group while Nogo-A, Aβ, NF-kB p65, P2X7, TNFα, MCP1, ROS, p47PHOX and MDA contents were significantly higher than those of control group;BDNF, SYN1, GPx and SOD contents in brain tissue of Dex group were significantly higher than those of propofol group while Nogo-A, Aβ, NF-kB p65, P2X7, TNFα, MCP1, ROS, p47PHOX and MDA contents were significantly lower than those propofol group.Conclusion: Dexmedetomidine can reduce the cognitive dysfunction induced by propofol and inhibit the apoptosis induced by inflammatory response and oxidative stress response.
文摘BACKGROUND:Interleukin-2 (IL-2) may influence the growth and survival of nerve cells following spi-nal cord injury and resuscitate the proliferation and maturation of oligodendrocytes. OBJECTIVE: To observe the effect of IL-2 on neuronal apoptosis of neurogliocytes at different times fol-lowing acute spinal cord injury in rats. DESIGN,TIME AND SETTING: A randomized grouping trial based on cellular morphology was per-formed at the Institute of Traumatic Orthopedics of Shandong Province between October 2004 and January 2006. MATERIALS: A total of 72 adult,male,Sprague Dawley rats were included in this study and were divided into a control group and an IL-2 group. The Bcl-2 monoclonal antibody and TUNEL kit were purchased from Wunan Boster Biological Technology Corporation. METHODS: Spinal cord injury was induced in all the rats by dropping a weight from a height of 25 cm onto the exposed spinal cord at vertebral levels T7-11,thus producing a mild lesion. Immediately following the modeling,the rats were injected with daily IL-2 (10 μL) intramuscularly (the IL-2 group). Other rats re-ceived an injection of physiological saline 0.5 mL/d (the control group). MAIN OUTCOME MEASURES: Bcl-2 immunohistochemistry was applied to detect the Bcl-protein and positive cell expression. The TUNEL method was used to count the number of apoptotic cells. RESULTS: The expression level of Bcl-2 proteins increased significantly in spinal cord tissues during the first day after acute spinal cord injury,reaching a peak on days 3 and days 8 in the control and IL-2 groups,respectively. They were more prevalent in neurogliocytes than in neurocytes,and then began to decrease on day 14. From then until day 21,less expression was detected (P < 0.05). In the control group,many apoptotic cells existed after 24 hours,and most of them were gliocytes; apoptotic cells reached a peak after 3-8 days. They then decreased gradually until day 21,when a small number of cells were still available. In the IL-2 group,the number of positive cells was significantly lower than in the control group (P < 0.05). CONCLUSION: The expression of Bcl-2 and the number of apoptotic cells in neurogliocytes undergo simi-lar changes with time after acute spinal cord injury. IL-2 may upregulate the expression of Bcl-2 proteins and decrease cell apoptosis in spinal cord tissue.
文摘Rat models of acute spinal cord injury and sciatic nerve injury were established.Apelin expression in spinal cord tissue was determined.In normal rat spinal cords,apelin expression was visible;however,2 hours post spinal cord injury,apelin expression peaked.Apelin expression increased 1 day post ligation of the sciatic nerve compared with normal rat spinal cords,and peaked at 3 days.Apelin expression was greater in the posterior horn compared with the anterior horn at each time point when compared with the normal group.The onset of neuronal apoptosis was significantly delayed following injection of apelin protein at the stump of the sciatic nerve,and the number of apoptotic cells after injury was reduced when compared with normal spinal cords.Our results indicate that apelin is expressed in the normal spinal cord and central nervous system after peripheral nerve injury.Apelin protein can reduce motor neuron apoptosis in the spinal cord anterior horn and delay the onset of apoptosis.
文摘This study sought to investigate the effects of Purendan superfine powder comprised of Momordica charantia, Radix Ginseng, and Radix Salviae Miltiorrhiae on neuronal apoptosis and expression of bcl-2, bax, and caspase-3, which are retinal apoptosis-associated factors in rats with diabetes mellitus induced by continuous intraperitoneal injection of streptozotocin. The results showed that Purendan superfine powder could upregulate the expression of bcl-2 protein and mRNA, and downregulate the expression of bax and caspase-3 in the retina of diabetes mellitus rats. In addition, Purendan superfine powder was shown to reduce the number of apoptotic neurons. Our experimental findings indicate that Purendan superfine powder can inhibit neuronal apoptosis in the retina of diabetes mellitus rats and has protective effects on diabetic retinopathy.
基金supported by the Developmental Fund of Chen Keji Integrative Medicine,No.CKJ2010025the Key Foundation of Society Development in Fujian Province,No.2013Y0059
文摘Wistar rats were intragastrically perfused with Chinese medicines used for tonifying the kidney.These included 0.180 g/mL of Herba Epimedii(Epimedium), Semen Cuscutae(Dodder Seed), or Herba Cistanches(Desertliving Cistanche), 0.04 mg/mL monoamine oxidase-B inhibitor selegiline,or distilled water for 14 consecutive days to prepare drug-containing serum or blank serum.MES23.5 cells in the logarithmic phase were cultured in media supplemented with 15%drug-containing serum for 24 hours, followed by incubation in culture solution containing 100 μmol/L H2O2for 3 hours. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) and flow cytometry results showed that all drug-containing serums improved the survival rate of H2O2-injured MES23.5 cells, inhibited pro-apoptotic FasL and caspase-3 expression, promoted anti-apoptotic Bcl-2 expression. However, drug-containing serums had little influence on Fas expression in H2O2-injured MES23.5 cells. Enzyme-linked immunosorbent assay results showed that serum containing Herba Cistanches or Herba Epimedii increased the expression of nerve growth factor,brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor in injured MES23.5cells; serum containing Semen Cuscutae only increased brain-derived neurotrophic factor expression; while expression of the above neurotrophic factors remained the same in cells treated with serum containing selegiline. These findings indicate that Chinese medicines used to tonify the kidney can protect nerve cells by regulating the expression of apoptosis-related factors and neurotrophic factors in MES23.5 cells.
基金supported by the National Natural Science Foundation of China,Nos.81971870,82172173(both to MCL)。
文摘Subarachnoid hemorrhage(SAH)is a dominant cause of death and disability wo rldwide.A sharp increase in intracranial pressure after SAH leads to a reduction in cerebral perfusion and insufficient blood supply for neuro ns,which subsequently promotes a series of pathophysiological responses leading to neuronal death.Many previous experimental studies have reported that excitotoxicity,mitochondrial death pathways,the release of free radicals,protein misfolding,apoptosis,nec rosis,autophagy,and inflammation are involved solely or in combination in this disorder.Among them,irreversible neuronal apoptosis plays a key role in both short-and long-term prognoses after SAH.Neuronal apoptosis occurs through multiple pathways including extrinsic,mitochondrial,endoplasmic reticulum,p53 and oxidative stress.Meanwhile,a large number of blood contents enter the subarachnoid space after SAH,and the secondary metabolites,including oxygenated hemoglo bin and heme,further aggravate the destruction of the blood-brain barrier and vasogenic and cytotoxic brain edema,causing early brain injury and delayed cerebral ischemia,and ultimately increasing neuronal apoptosis.Even there is no clear and effective therapeutic strategy for SAH thus far,but by understanding apoptosis,we might excavate new ideas and approaches,as targeting the upstream and downstream molecules of apoptosis-related pathways shows promise in the treatment of SAH.In this review,we summarize the existing evidence on molecules and related drugs or molecules involved in the apoptotic pathway after SAH,which provides a possible target or new strategy for the treatment of SAH.
基金supported by the National Natural Science Foundation of China,No.81772452(to NL)the Fujian Province Joint Funds for the Innovation of Science and Technology,No.2020Y9065(to NL)+1 种基金Fujian Province Special Foundation for Natural Science Innovation Project,No.2016B014(to NL)the Natural Science Foundation of Fujian Province,No.2019J01160(to XHJ).
文摘Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia.However,whether there is a synergistic effect between the two remains unclear.In this study,we established rat models of ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours.Rat models were perfused with bone marrow mesenchymal stem cell-derived exosomes(MSC-exos)via the tail vein and underwent 14 successive days of treadmill exercise.Neurological assessment,histopathology,and immunohistochemistry results revealed decreased neuronal apoptosis and cerebral infarct volume,evident synaptic formation and axonal regeneration,and remarkably recovered neurological function in rats subjected to treadmill exercise and MSC-exos treatment.These effects were superior to those in rats subjected to treadmill exercise or MSC-exos treatment alone.Mechanistically,further investigation revealed that the activation of JNK1/c-Jun signaling pathways regulated neuronal apoptosis and synaptic-axonal remodeling.These findings suggest that treadmill exercise may exhibit a synergistic effect with MSC-exos treatment,which may be related to activation of the JNK1/c-Jun signaling pathway.This study provides novel theoretical evidence for the clinical application of treadmill exercise combined with MSC-exos treatment for ischemic cerebrovascular disease.
基金supported by the Natural Science Foundation of Liaoning Province,No.2021-MS-061(to LZhang)。
文摘Circular RNAs can regulate the development and progression of ischemic cerebral disease.However,it remains unclear whether they play a role in acute ischemic stroke.To investigate the role of the circular RNA Rap1b(circRap1b)in acute ischemic stroke,in this study we established an in vitro model of acute ischemia and hypoxia by subjecting HT22 cells to oxygen and glucose deprivation and a mouse model of acute ischemia and hypoxia by occluding the right carotid artery.We found that circRap1b expression was remarkably down-regulated in the hippocampal tissue of the mouse model and in the HT22 cell model.In addition,Hoxa5 expression was strongly up-regulated in response to circRap1b overexpression.Hoxa5 expression was low in the hippocampus of a mouse model of acute ischemia and in HT22-AIS cells,and inhibited HT22-AIS cell apoptosis.Importantly,we found that circRap1b promoted Hoxa5 transcription by recruiting the acetyltransferase Kat7 to induce H3K14ac modification in the Hoxa5 promoter region.Hoxa5 regulated neuronal apoptosis by activating transcription of Fam3a,a neuronal apoptosis-related protein.These results suggest that circRap1b regulates Hoxa5 transcription and expression,and subsequently Fam3a expression,ultimately inhibiting cell apoptosis.Lastly,we explored the potential clinical relevance of circRap1b and Hoxa5 in vivo.Taken together,these findings demonstrate the mechanism by which circRap1b inhibits neuronal apoptosis in acute ischemic stroke.
基金supported by the Natural Science Foundation of ChinaNos.81971212 (to FG)+7 种基金81601129 (to XXX)the Open Fund of the Key Laboratory of Medical ElectrophysiologyMinistry of Education&Medical Electrophysiological Key Laboratory of Sichuan ProvinceInstitute of Cardiovascular ResearchSouthwest Medical UniversityNo.KeyME-2018-07 (to FG)Liaoning Province Xingliao Talent Program ProjectNo.XLYC1907164 (to FG)
文摘Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold,that is,has an anticonvulsant effect.However,the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear.In this study,we performed RNA sequencing,functional enrichment analysis,and weighted gene coexpression network analysis of the hippocampus of tremor rats,a rat model of genetic epilepsy.We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity.In addition,we used a pilocarpine-induced N2a cell model to mimic epileptic injury.After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole,changes in malondialdehyde,lactate dehydrogenase and superoxide dismutase,which are associated with oxidative stress,were reversed,and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine.Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells.Furthermore,7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3,gasdermin-D,interleukin-1βand interleukin-18.This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death.Taken together,our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells,and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.
基金Natural Science Foundation of Liaoning Province (General Program),No.2017010825 (to JQ)。
文摘Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.
基金supported by the Haihe Laboratory of Cell Ecosystem Innovation Fund,No.22HHXBSS00047(to PL)the National Natural Science Foundation of China,Nos.82072166(to PL),82071394(to XG)+4 种基金Science and Technology Planning Project of Tianjin,No.20YFZCSY00030(to PL)Science and Technology Project of Tianjin Municipal Health Commission,No.TJWJ2021QN005(to XG)Tianjin Key Medical Discipline(Specialty)Construction Project,No.TJYXZDXK-006ATianjin Municipal Education Commission Scientific Research Program Project,No.2020KJ164(to JZ)China Postdoctoral Science Foundation,No.2022M712392(to ZY).
文摘We previously reported that miR-124-3p is markedly upregulated in microglia-derived exosomes following repetitive mild traumatic brain injury.However,its impact on neuronal endoplasmic reticulum stress following repetitive mild traumatic brain injury remains unclear.In this study,we first used an HT22 scratch injury model to mimic traumatic brain injury,then co-cultured the HT22 cells with BV2 microglia expressing high levels of miR-124-3p.We found that exosomes containing high levels of miR-124-3p attenuated apoptosis and endoplasmic reticulum stress.Furthermore,luciferase reporter assay analysis confirmed that miR-124-3p bound specifically to the endoplasmic reticulum stress-related protein IRE1α,while an IRE1αfunctional salvage experiment confirmed that miR-124-3p targeted IRE1αand reduced its expression,thereby inhibiting endoplasmic reticulum stress in injured neurons.Finally,we delivered microglia-derived exosomes containing miR-124-3p intranasally to a mouse model of repetitive mild traumatic brain injury and found that endoplasmic reticulum stress and apoptosis levels in hippocampal neurons were significantly reduced.These findings suggest that,after repetitive mild traumatic brain injury,miR-124-3 can be transferred from microglia-derived exosomes to injured neurons,where it exerts a neuroprotective effect by inhibiting endoplasmic reticulum stress.Therefore,microglia-derived exosomes containing miR-124-3p may represent a novel therapeutic strategy for repetitive mild traumatic brain injury.
基金supported by the National Natural Science Foundation of China,No.82272478(to PT)。
文摘Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury(SCI).However,this subject has been neglected in part because appropriate tools are lacking.Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease.This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques,and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI.We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations.Finally,we identify the challenges and possible solutions for spinal cord neuron imaging.
基金funded by the Gerald Kerkut Charitable Trust (GKT)(to BR)
文摘Aging is the leading risk factor for Alzheimer’s disease and other neurodegenerative diseases. We now understand that a breakdown in the neuronal cytoskeleton, mainly underpinned by protein modifications leading to the destabilization of microtubules, is central to the pathogenesis of Alzheimer’s disease. This is accompanied by morphological defects across the somatodendritic compartment, axon, and synapse. However, knowledge of what occurs to the microtubule cytoskeleton and morphology of the neuron during physiological aging is comparatively poor. Several recent studies have suggested that there is an age-related increase in the phosphorylation of the key microtubule stabilizing protein tau, a modification, which is known to destabilize the cytoskeleton in Alzheimer’s disease. This indicates that the cytoskeleton and potentially other neuronal structures reliant on the cytoskeleton become functionally compromised during normal physiological aging. The current literature shows age-related reductions in synaptic spine density and shifts in synaptic spine conformation which might explain age-related synaptic functional deficits. However, knowledge of what occurs to the microtubular and actin cytoskeleton, with increasing age is extremely limited. When considering the somatodendritic compartment, a regression in dendrites and loss of dendritic length and volume is reported whilst a reduction in soma volume/size is often seen. However, research into cytoskeletal change is limited to a handful of studies demonstrating reductions in and mislocalizations of microtubule-associated proteins with just one study directly exploring the integrity of the microtubules. In the axon, an increase in axonal diameter and age-related appearance of swellings is reported but like the dendrites, just one study investigates the microtubules directly with others reporting loss or mislocalization of microtubule-associated proteins. Though these are the general trends reported, there are clear disparities between model organisms and brain regions that are worthy of further investigation. Additionally, longitudinal studies of neuronal/cytoskeletal aging should also investigate whether these age-related changes contribute not just to vulnerability to disease but also to the decline in nervous system function and behavioral output that all organisms experience. This will highlight the utility, if any, of cytoskeletal fortification for the promotion of healthy neuronal aging and potential protection against age-related neurodegenerative disease. This review seeks to summarize what is currently known about the physiological aging of the neuron and microtubular cytoskeleton in the hope of uncovering mechanisms underpinning age-related risk to disease.
基金supported by the National Natural Science Foundation of China,No.82073783(to YY)the Natural Science Foundation of Beijing,No.7212160(to YY).
文摘Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogramming is a promising strategy to convert glial scars to neural tissue.However,previous studies have reported inconsistent results.In this study,an AAV9P1 vector incorporating an astrocyte-targeting P1 peptide and glial fibrillary acidic protein promoter was used to achieve dual-targeting of astrocytes and the glial scar while minimizing off-target effects.The results demonstrate that AAV9P1 provides high selectivity of astrocytes and reactive astrocytes.Moreover,neuronal reprogramming was induced by downregulating the polypyrimidine tract-binding protein 1 gene via systemic administration of AAV9P1 in a mouse model of traumatic brain injury.In summary,this approach provides an improved gene delivery vehicle to study neuronal programming and evidence of its applications for traumatic brain injury.
