OBJECTIVE To investigate the effect of neuroprotective effect of lychee seed saponins(LSS) in BV-2.METHODS Aβ_(1-42) induced BV-2 cells were incubated with LSS for 12 h,the content of the inflammatory factors such as...OBJECTIVE To investigate the effect of neuroprotective effect of lychee seed saponins(LSS) in BV-2.METHODS Aβ_(1-42) induced BV-2 cells were incubated with LSS for 12 h,the content of the inflammatory factors such as IL^(-1)β,TNF-α,COX-2 and i NOS in the supernatant of BV-2 cell were measured by ELISA.The detection of the m RNA levels and the protein expression of the inflammatory factors including IL^(-1)β,TNF-α,COX-2 and i NOS using real-time PCR and Western blotting,respectively.RESULTS The level of IL^(-1)β,COX-2 and i NOS significantly increased with the treatment of Aβ_(1-42),and 0.117 mg·L^(-1)-0.469 mg·L^(-1) LSS can inhibit these increased level.CONCLUSION LSS conferred neuroprotection via inhibiting the inflammatory factors expression.展开更多
Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PT...Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.展开更多
Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life ...Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.展开更多
目的探究灯盏乙素(Scutellarin)对脂多糖(Lipopolysaccharide,LPS)作用下M2型小胶质细胞极化的作用及信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)的调控机制。方法BV-2小胶质细胞分为对照组(...目的探究灯盏乙素(Scutellarin)对脂多糖(Lipopolysaccharide,LPS)作用下M2型小胶质细胞极化的作用及信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)的调控机制。方法BV-2小胶质细胞分为对照组(Con组)、STAT3抑制剂α-氰基-(3,4-二羟基)-N-苄基霉素-烟酰胺组(AG490组)、LPS组、LPS+AG490组、LPS+灯盏乙素预处理组(LPS+S组)、LPS+S+AG490组,共6组。Western blot和免疫荧光染色检测STAT3、磷酸化STAT3(P-STAT3)和M2型小胶质细胞标记物白介素10(IL-10)的表达。结果Western blot结果显示,LPS组的P-STAT3、IL-10表达显著增强,与对照组差异显著(P<0.05);使用灯盏乙素干预后P-STAT3表达明显降低;IL-10表达显著增高;均与LPS组有显著差异(P<0.05)。AG490增强灯盏乙素的作用。此外,STAT3在各组的变化无统计学意义(P>0.05)。免疫荧光染色结果显示,灯盏乙素干预后可降低LPS激活的BV-2小胶质细胞P-STAT3的蛋白表达水平;增强IL-10蛋白表达。各组STAT3的蛋白水平无统计学意义。结论灯盏乙素通过抑制STAT3活化促进BV-2小胶质细胞向M2型极化,可能与灯盏乙素减轻神经炎症反应有关。展开更多
Triggering receptor expressed on myeloid cells-like 2(TREML2)is a newly identified susceptibility gene for Alzheimer's disease(AD).It encodes a microglial inflammation-associated receptor.To date,the potential rol...Triggering receptor expressed on myeloid cells-like 2(TREML2)is a newly identified susceptibility gene for Alzheimer's disease(AD).It encodes a microglial inflammation-associated receptor.To date,the potential role of mic roglial TREML2 in neuroinflammation in the context of AD remains unclear.In this study,APP/PS1 mice were used to investigate the dynamic changes of TREML2 levels in brain during AD progression.In addition,lipopolysaccharide(LPS)stimulation of primary microglia as well as a lentivirus-mediated TREML2 overexpression and knockdown were employed to explore the role of TREML2 in neuroinflammation in the context of AD.Our res ults show that TREML2 levels gradually increased in the brains of AP P/PS1 mice during disease progression.LPS stimulation of primary microglia led to the release of inflammato ry cytokines including interleukin-1β,inte rleukin-6,and tumor necrosis factor-a in the culture medium.The LPS-induced mic roglial release of inflammatory cytokines was enhanced by TREML2 overexpression and was attenuated by TREML2 knoc kdown.LPS increased the levels of mic roglial M1-type polarization marker inducible nitric oxide synthase.This effect was enhanced by TREML2 overexpression and ameliorated by TREML2 knockdown.Furthermore,the levels of microglial M2-type polarization markers CD206 and ARG1 in the primary microglia were reduced by TREML2 overexpression and elevated by TREML2 knockdown.LPS stimulation increased the levels of NLRP3 in primary microglia.The LPS-induced increase in NLRP3 was further elevated by TREML2 overexpression and alleviated by TREML2 knockdown.In summary,this study provides the first evidence that TREML2 modulates inflammation by regulating microglial polarization and NLRP3 inflammasome activation.These findings reveal the mechanisms by which TREML2 regulates microglial inflammation and suggest that TREML2 inhibition may represent a novel therapeutic strategy for AD.展开更多
Poly(ADP-ribose)polymerase family member 14(PARP14),which is an intracellular mono(ADP-ribosyl)transferase,has been reported to promote post-stroke functional recovery,but its role in spinal cord injury(SCI)remains un...Poly(ADP-ribose)polymerase family member 14(PARP14),which is an intracellular mono(ADP-ribosyl)transferase,has been reported to promote post-stroke functional recovery,but its role in spinal cord injury(SCI)remains unclear.To investigate this,a T10 spinal cord contusion model was established in C57BL/6 mice,and immediately after the injury PARP14 shRNA-carrying lentivirus was injected 1 mm from the injury site to silence PARP14 expression.We found that PARP14 was up-regulated in the injured spinal cord and that lentivirus-mediated downregulation of PARP14 aggravated functional impairment after injury,accompanied by obvious neuronal apoptosis,severe neuroinflammation,and slight bone loss.Furthermore,PARP14 levels were elevated in microglia after SCI,PARP14 knockdown activated microglia in the spinal cord and promoted a shift from M2-polarized microglia(anti-inflammatory phenotype)to M1-polarized microglia(pro-inflammatory phenotype)that may have been mediated by the signal transducers and activators of transcription(STAT)1/6 pathway.Next,microglia M1 and M2 polarization were induced in vitro using lipopolysaccharide/interferon-γand interleukin-4,respectively.The results showed that PARP14 knockdown promoted microglia M1 polarization,accompanied by activation of the STAT1 pathway.In addition,PARP14 overexpression made microglia more prone to M2 polarization and further activated the STAT6 pathway.In conclusion,these findings suggest that PARP14 may improve functional recovery after SCI by regulating the phenotypic transformation of microglia via the STAT1/6 pathway.展开更多
Elongation factor Tu GTP binding domain protein 2(Eftud2)is a spliceosomal GTPase that serves as an innate immune modulator restricting virus infection.Microglia are the resident innate immune cells and the key player...Elongation factor Tu GTP binding domain protein 2(Eftud2)is a spliceosomal GTPase that serves as an innate immune modulator restricting virus infection.Microglia are the resident innate immune cells and the key players of immune response in the central nervous system.However,the role of Eftud2 in microglia has not been reported.In this study,we performed immunofluorescent staining and western blot assay and found that Eftud2 was upregulated in microglia of a 5xFAD transgenic mouse model of Alzheimer’s disease.Next,we generated an inducible microglia-specific Eftud2 conditional knockout mouse line(CX3CR1-CreER;Eftud2^(f/f) cKO)via Cre/loxP recombination and found that Eftud2 deficiency resulted in abnormal proliferation and promoted anti-inflammatory phenotype activation of microglia.Furthermore,we knocked down Eftud2 in BV2 microglia with siRNA specifically targeting Eftud2 and found that Eftud2-mediated regulation of microglial proinflammatory/anti-inflammatory phenotype activation in response to inflammation might be dependent on the NF-κB signaling pathway.Our findings suggest that Eftud2 plays a key role in regulating microglial polarization and homeostasis possibly through the NF-κB signaling pathway.展开更多
Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood cl...Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood clots have been shown to elicit secondary brain injury after germinal matrix hemorrhage,by disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage causing post-hemorrhagic hydrocephalus development.Current evidence suggests that rapid hematoma resolution is necessary to improve neurological outcomes after hemorrhagic stroke.Various articles have demonstrated the beneficial effects of stimulating the polarization of microglia cells into the M2 phenotype,as it has been suggested that they play an essential role in the rapid phagocytosis of the blood clot after hemorrhagic models of stroke.N-formyl peptide receptor 2(FPR2),a G-protein-coupled receptor,has been shown to be neuroprotective after stroke.FPR2 activation has been associated with the upregulation of phagocytic macrophage clearance,yet its mechanism has not been fully explored.Recent literature suggests that FPR2 may play a role in the stimulation of scavenger receptor CD36.Scavenger receptor CD36 plays a vital role in microglia phagocytic blood clot clearance after germinal matrix hemorrhage.FPR2 has been shown to phosphorylate extracellular-signal-regulated kinase 1/2(ERK1/2),which then promotes the transcription of the dual-specificity protein phosphatase 1(DUSP1)gene.In this review,we present an intrinsic outline of the main components involved in FPR2 stimulation and hematoma resolution after germinal matrix hemorrhage.展开更多
Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery...Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.展开更多
Little is known about whether tamoxifen (TAM) can affect resting state microglia apoptosis and about the cellular mechanism that may account for this. To explore this question, we incubated the microglia cell line BV-...Little is known about whether tamoxifen (TAM) can affect resting state microglia apoptosis and about the cellular mechanism that may account for this. To explore this question, we incubated the microglia cell line BV-2 cells with TAM at different concentrations. Cell viability was assessed by the MTT assay, and flow cytometric analysis was performed to detect the cell apoptosis rate. Furthermore, mitochondrial membrane potential (Δψm) was tested by flow cytometry, and Bax, Bcl-2, Fas, and Fas-L expression was detected by Western blot. The results demonstrated that TAM decreased cell viability and induced apoptosis of BV-2 cells in a concentration- and time-dependent manner. In addition, disruption of Δψm was followed by up-regulated expression of pro-apoptotic Bax, Fas and Fas-L, and down-regulated expression of anti-apoptotic Bcl-2. These results indicate that TAM may induce apoptosis of BV-2 cells through both mitochondria- and death receptor-mediated pathways.展开更多
Prion diseases are infectious and fatal neurodegenerative diseases.The pathogenic agent is an abnormal prion protein aggregate.Microglial activation in the centre nervous system is a characteristic feature of prion di...Prion diseases are infectious and fatal neurodegenerative diseases.The pathogenic agent is an abnormal prion protein aggregate.Microglial activation in the centre nervous system is a characteristic feature of prion disease.In this study,we examined the effect of PrP 106-126 on PrP mRNA gene expression in Mouse microglia cells BV-2 by real-time quantitative PCR.PrP mRNA expression level was found to be significantly increased after 18 h exposure of BV-2 cells to PrP 106-126,with 3-fold increase after 18 h and 4.5-fold increase after 24 h and BV-2 cells proliferating occurred correspondingly.Our results provide the first in vitro evidence of the increase of PrP mRNA levels in microglial cells exposed to PrP 106-126,and indicate that microglial cells might play a critical role in prion pathogenesis.展开更多
文摘OBJECTIVE To investigate the effect of neuroprotective effect of lychee seed saponins(LSS) in BV-2.METHODS Aβ_(1-42) induced BV-2 cells were incubated with LSS for 12 h,the content of the inflammatory factors such as IL^(-1)β,TNF-α,COX-2 and i NOS in the supernatant of BV-2 cell were measured by ELISA.The detection of the m RNA levels and the protein expression of the inflammatory factors including IL^(-1)β,TNF-α,COX-2 and i NOS using real-time PCR and Western blotting,respectively.RESULTS The level of IL^(-1)β,COX-2 and i NOS significantly increased with the treatment of Aβ_(1-42),and 0.117 mg·L^(-1)-0.469 mg·L^(-1) LSS can inhibit these increased level.CONCLUSION LSS conferred neuroprotection via inhibiting the inflammatory factors expression.
基金supported by the Natural Science Research Project of Anhui Province University, No.2023AH040394 (to TY)Hefei Comprehensive National Science Center Leading Medicine and Frontier Technology Research Institute Project, No.2023IHM01073 (to TY)the Natural Science Foundation of Anhui Province, Nos.2308085QH258 (to JW), 2008085MH246 (to TY)。
文摘Reducing the secondary inflammatory response, which is partly mediated by microglia, is a key focus in the treatment of spinal cord injury. Src homology 2-containing protein tyrosine phosphatase 2(SHP2), encoded by PTPN11, is widely expressed in the human body and plays a role in inflammation through various mechanisms. Therefore, SHP2 is considered a potential target for the treatment of inflammation-related diseases. However, its role in secondary inflammation after spinal cord injury remains unclear. In this study, SHP2 was found to be abundantly expressed in microglia at the site of spinal cord injury. Inhibition of SHP2 expression using siRNA and SHP2 inhibitors attenuated the microglial inflammatory response in an in vitro lipopolysaccharide-induced model of inflammation. Notably, after treatment with SHP2 inhibitors, mice with spinal cord injury exhibited significantly improved hind limb locomotor function and reduced residual urine volume in the bladder. Subsequent in vitro experiments showed that, in microglia stimulated with lipopolysaccharide, inhibiting SHP2 expression promoted M2 polarization and inhibited M1 polarization. Finally, a co-culture experiment was conducted to assess the effect of microglia treated with SHP2 inhibitors on neuronal cells. The results demonstrated that inflammatory factors produced by microglia promoted neuronal apoptosis, while inhibiting SHP2 expression mitigated these effects. Collectively, our findings suggest that SHP2 enhances secondary inflammation and neuronal damage subsequent to spinal cord injury by modulating microglial phenotype. Therefore, inhibiting SHP2 alleviates the inflammatory response in mice with spinal cord injury and promotes functional recovery postinjury.
基金supported by the National Natural Science Foundation of China,Nos.81730033,82171193(to XG)the Key Talent Project for Strengthening Health during the 13^(th)Five-Year Plan Period,No.ZDRCA2016069(to XG)+1 种基金the National Key R&D Program of China,No.2018YFC2001901(to XG)Jiangsu Provincial Medical Key Discipline,No.ZDXK202232(to XG)。
文摘Postoperative cognitive dysfunction is a seve re complication of the central nervous system that occurs after anesthesia and surgery,and has received attention for its high incidence and effect on the quality of life of patients.To date,there are no viable treatment options for postoperative cognitive dysfunction.The identification of postoperative cognitive dysfunction hub genes could provide new research directions and therapeutic targets for future research.To identify the signaling mechanisms contributing to postoperative cognitive dysfunction,we first conducted Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses of the Gene Expression Omnibus GSE95426 dataset,which consists of mRNAs and long non-coding RNAs differentially expressed in mouse hippocampus3 days after tibial fracture.The dataset was enriched in genes associated with the biological process"regulation of immune cells,"of which Chill was identified as a hub gene.Therefore,we investigated the contribution of chitinase-3-like protein 1 protein expression changes to postoperative cognitive dysfunction in the mouse model of tibial fractu re surgery.Mice were intraperitoneally injected with vehicle or recombinant chitinase-3-like protein 124 hours post-surgery,and the injection groups were compared with untreated control mice for learning and memory capacities using the Y-maze and fear conditioning tests.In addition,protein expression levels of proinflammatory factors(interleukin-1βand inducible nitric oxide synthase),M2-type macrophage markers(CD206 and arginase-1),and cognition-related proteins(brain-derived neurotropic factor and phosphorylated NMDA receptor subunit NR2B)were measured in hippocampus by western blotting.Treatment with recombinant chitinase-3-like protein 1 prevented surgery-induced cognitive impairment,downregulated interleukin-1βand nducible nitric oxide synthase expression,and upregulated CD206,arginase-1,pNR2B,and brain-derived neurotropic factor expression compared with vehicle treatment.Intraperitoneal administration of the specific ERK inhibitor PD98059 diminished the effects of recombinant chitinase-3-like protein 1.Collectively,our findings suggest that recombinant chitinase-3-like protein 1 ameliorates surgery-induced cognitive decline by attenuating neuroinflammation via M2 microglial polarization in the hippocampus.Therefore,recombinant chitinase-3-like protein1 may have therapeutic potential fo r postoperative cognitive dysfunction.
文摘目的探究灯盏乙素(Scutellarin)对脂多糖(Lipopolysaccharide,LPS)作用下M2型小胶质细胞极化的作用及信号转导和转录激活因子3(signal transducers and activators of transcription 3,STAT3)的调控机制。方法BV-2小胶质细胞分为对照组(Con组)、STAT3抑制剂α-氰基-(3,4-二羟基)-N-苄基霉素-烟酰胺组(AG490组)、LPS组、LPS+AG490组、LPS+灯盏乙素预处理组(LPS+S组)、LPS+S+AG490组,共6组。Western blot和免疫荧光染色检测STAT3、磷酸化STAT3(P-STAT3)和M2型小胶质细胞标记物白介素10(IL-10)的表达。结果Western blot结果显示,LPS组的P-STAT3、IL-10表达显著增强,与对照组差异显著(P<0.05);使用灯盏乙素干预后P-STAT3表达明显降低;IL-10表达显著增高;均与LPS组有显著差异(P<0.05)。AG490增强灯盏乙素的作用。此外,STAT3在各组的变化无统计学意义(P>0.05)。免疫荧光染色结果显示,灯盏乙素干预后可降低LPS激活的BV-2小胶质细胞P-STAT3的蛋白表达水平;增强IL-10蛋白表达。各组STAT3的蛋白水平无统计学意义。结论灯盏乙素通过抑制STAT3活化促进BV-2小胶质细胞向M2型极化,可能与灯盏乙素减轻神经炎症反应有关。
基金supported by the National Natural Science Foundation of china,No.81974156(to TJ)the Natural Science Foundation of Jiangsu Province,No.BK20201117(to YDZ)。
文摘Triggering receptor expressed on myeloid cells-like 2(TREML2)is a newly identified susceptibility gene for Alzheimer's disease(AD).It encodes a microglial inflammation-associated receptor.To date,the potential role of mic roglial TREML2 in neuroinflammation in the context of AD remains unclear.In this study,APP/PS1 mice were used to investigate the dynamic changes of TREML2 levels in brain during AD progression.In addition,lipopolysaccharide(LPS)stimulation of primary microglia as well as a lentivirus-mediated TREML2 overexpression and knockdown were employed to explore the role of TREML2 in neuroinflammation in the context of AD.Our res ults show that TREML2 levels gradually increased in the brains of AP P/PS1 mice during disease progression.LPS stimulation of primary microglia led to the release of inflammato ry cytokines including interleukin-1β,inte rleukin-6,and tumor necrosis factor-a in the culture medium.The LPS-induced mic roglial release of inflammatory cytokines was enhanced by TREML2 overexpression and was attenuated by TREML2 knoc kdown.LPS increased the levels of mic roglial M1-type polarization marker inducible nitric oxide synthase.This effect was enhanced by TREML2 overexpression and ameliorated by TREML2 knockdown.Furthermore,the levels of microglial M2-type polarization markers CD206 and ARG1 in the primary microglia were reduced by TREML2 overexpression and elevated by TREML2 knockdown.LPS stimulation increased the levels of NLRP3 in primary microglia.The LPS-induced increase in NLRP3 was further elevated by TREML2 overexpression and alleviated by TREML2 knockdown.In summary,this study provides the first evidence that TREML2 modulates inflammation by regulating microglial polarization and NLRP3 inflammasome activation.These findings reveal the mechanisms by which TREML2 regulates microglial inflammation and suggest that TREML2 inhibition may represent a novel therapeutic strategy for AD.
基金supported by the Shenyang Science and Technology Project,No.20-205-4-092(to AHX)。
文摘Poly(ADP-ribose)polymerase family member 14(PARP14),which is an intracellular mono(ADP-ribosyl)transferase,has been reported to promote post-stroke functional recovery,but its role in spinal cord injury(SCI)remains unclear.To investigate this,a T10 spinal cord contusion model was established in C57BL/6 mice,and immediately after the injury PARP14 shRNA-carrying lentivirus was injected 1 mm from the injury site to silence PARP14 expression.We found that PARP14 was up-regulated in the injured spinal cord and that lentivirus-mediated downregulation of PARP14 aggravated functional impairment after injury,accompanied by obvious neuronal apoptosis,severe neuroinflammation,and slight bone loss.Furthermore,PARP14 levels were elevated in microglia after SCI,PARP14 knockdown activated microglia in the spinal cord and promoted a shift from M2-polarized microglia(anti-inflammatory phenotype)to M1-polarized microglia(pro-inflammatory phenotype)that may have been mediated by the signal transducers and activators of transcription(STAT)1/6 pathway.Next,microglia M1 and M2 polarization were induced in vitro using lipopolysaccharide/interferon-γand interleukin-4,respectively.The results showed that PARP14 knockdown promoted microglia M1 polarization,accompanied by activation of the STAT1 pathway.In addition,PARP14 overexpression made microglia more prone to M2 polarization and further activated the STAT6 pathway.In conclusion,these findings suggest that PARP14 may improve functional recovery after SCI by regulating the phenotypic transformation of microglia via the STAT1/6 pathway.
基金supported by the National Natural Science Foundation of China,Nos.32171148,31770929,31522029(all to HTW)the National Key Research and Development Program of China,Nos.2021ZD0202500,2021YFA1101801(both to HTW)a grant from Beijing Commission of Science and Technology of China,Nos.Z181100001518001,Z161100000216154(both to HTW)。
文摘Elongation factor Tu GTP binding domain protein 2(Eftud2)is a spliceosomal GTPase that serves as an innate immune modulator restricting virus infection.Microglia are the resident innate immune cells and the key players of immune response in the central nervous system.However,the role of Eftud2 in microglia has not been reported.In this study,we performed immunofluorescent staining and western blot assay and found that Eftud2 was upregulated in microglia of a 5xFAD transgenic mouse model of Alzheimer’s disease.Next,we generated an inducible microglia-specific Eftud2 conditional knockout mouse line(CX3CR1-CreER;Eftud2^(f/f) cKO)via Cre/loxP recombination and found that Eftud2 deficiency resulted in abnormal proliferation and promoted anti-inflammatory phenotype activation of microglia.Furthermore,we knocked down Eftud2 in BV2 microglia with siRNA specifically targeting Eftud2 and found that Eftud2-mediated regulation of microglial proinflammatory/anti-inflammatory phenotype activation in response to inflammation might be dependent on the NF-κB signaling pathway.Our findings suggest that Eftud2 plays a key role in regulating microglial polarization and homeostasis possibly through the NF-κB signaling pathway.
基金supported in part by the National Institutes of Health grant 5R01NS117364-02(to JT)。
文摘Germinal matrix hemorrhage is one of the leading causes of morbidity,mortality,and acquired infantile hydrocephalus in preterm infants in the United States,with little progress made in its clinical management.Blood clots have been shown to elicit secondary brain injury after germinal matrix hemorrhage,by disrupting normal cerebrospinal fluid circulation and absorption after germinal matrix hemorrhage causing post-hemorrhagic hydrocephalus development.Current evidence suggests that rapid hematoma resolution is necessary to improve neurological outcomes after hemorrhagic stroke.Various articles have demonstrated the beneficial effects of stimulating the polarization of microglia cells into the M2 phenotype,as it has been suggested that they play an essential role in the rapid phagocytosis of the blood clot after hemorrhagic models of stroke.N-formyl peptide receptor 2(FPR2),a G-protein-coupled receptor,has been shown to be neuroprotective after stroke.FPR2 activation has been associated with the upregulation of phagocytic macrophage clearance,yet its mechanism has not been fully explored.Recent literature suggests that FPR2 may play a role in the stimulation of scavenger receptor CD36.Scavenger receptor CD36 plays a vital role in microglia phagocytic blood clot clearance after germinal matrix hemorrhage.FPR2 has been shown to phosphorylate extracellular-signal-regulated kinase 1/2(ERK1/2),which then promotes the transcription of the dual-specificity protein phosphatase 1(DUSP1)gene.In this review,we present an intrinsic outline of the main components involved in FPR2 stimulation and hematoma resolution after germinal matrix hemorrhage.
基金supported by the Research Foundation of Technology Committee of Tongzhou District,No.KJ2019CX001(to SX).
文摘Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury.However,whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear.In the present study,we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells.We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury,decreased expression of the microglial pyroptosis markers NLRP3,GSDMD,caspase-1,and interleukin-1β,promoted axonal and myelin regeneration,and inhibited the formation of glial scars.In addition,in a lipopolysaccharide-induced BV2 microglia model,conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway.These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1βpathway,thereby promoting the recovery of neurological function after spinal cord injury.Therefore,conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.
基金supported by a grant from the National Natu-ral Science Foundation of China(No.30900449)
文摘Little is known about whether tamoxifen (TAM) can affect resting state microglia apoptosis and about the cellular mechanism that may account for this. To explore this question, we incubated the microglia cell line BV-2 cells with TAM at different concentrations. Cell viability was assessed by the MTT assay, and flow cytometric analysis was performed to detect the cell apoptosis rate. Furthermore, mitochondrial membrane potential (Δψm) was tested by flow cytometry, and Bax, Bcl-2, Fas, and Fas-L expression was detected by Western blot. The results demonstrated that TAM decreased cell viability and induced apoptosis of BV-2 cells in a concentration- and time-dependent manner. In addition, disruption of Δψm was followed by up-regulated expression of pro-apoptotic Bax, Fas and Fas-L, and down-regulated expression of anti-apoptotic Bcl-2. These results indicate that TAM may induce apoptosis of BV-2 cells through both mitochondria- and death receptor-mediated pathways.
基金National Natural Science Foundations ofChina (30871854)National Science and Technology Supporting Program of China (2006BAD06A13)
文摘Prion diseases are infectious and fatal neurodegenerative diseases.The pathogenic agent is an abnormal prion protein aggregate.Microglial activation in the centre nervous system is a characteristic feature of prion disease.In this study,we examined the effect of PrP 106-126 on PrP mRNA gene expression in Mouse microglia cells BV-2 by real-time quantitative PCR.PrP mRNA expression level was found to be significantly increased after 18 h exposure of BV-2 cells to PrP 106-126,with 3-fold increase after 18 h and 4.5-fold increase after 24 h and BV-2 cells proliferating occurred correspondingly.Our results provide the first in vitro evidence of the increase of PrP mRNA levels in microglial cells exposed to PrP 106-126,and indicate that microglial cells might play a critical role in prion pathogenesis.
