BACKGROUND Bone marrow mesenchymal stem cells(BMSCs)are capable of shifting the microglia/macrophages phenotype from M1 to M2,contributing to BMSCsinduced brain repair.However,the regulatory mechanism of BMSCs on micr...BACKGROUND Bone marrow mesenchymal stem cells(BMSCs)are capable of shifting the microglia/macrophages phenotype from M1 to M2,contributing to BMSCsinduced brain repair.However,the regulatory mechanism of BMSCs on microglia/macrophages after ischemic stroke is unclear.Recent evidence suggests that mesencephalic astrocyte-derived neurotrophic factor(MANF)and plateletderived growth factor-AA(PDGF-AA)/MANF signaling regulate M1/M2 macrophage polarization.AIM To investigate whether and how MANF or PDGF-AA/MANF signaling influences BMSCs-mediated M2 polarization.METHODS We identified the secretion of MANF by BMSCs and developed transgenic BMSCs using a targeting small interfering RNA for knockdown of MANF expression.Using a rat middle cerebral artery occlusion(MCAO)model transplanted by BMSCs and BMSCs-microglia Transwell coculture system,the effect of BMSCsinduced downregulation of MANF expression on the phenotype of microglia/macrophages was tested by Western blot,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence.Additionally,microglia were transfected with mimics of miR-30a*,which inuenced expression of X-box binding protein(XBP)1,a key transcription factor that synergized with activating transcription factor 6(ATF6)to govern MANF expression.We examined the levels of miR-30a*,ATF6,XBP1,and MANF after PDGF-AA treatment in the activated microglia.RESULTS Inhibition of MANF attenuated BMSCs-induced functional recovery and decreased M2 marker production,but increased M1 marker expression in vivo or in vitro.Furthermore,PDGF-AA treatment decreased miR-30a*expression,had no influence on the levels of ATF6,but enhanced expression of both XBP1 and MANF.CONCLUSION BMSCs-mediated MANF paracrine signaling,in particular the PDGF-AA/miR-30a*/XBP1/MANF pathway,synergistically mediates BMSCs-induced M2 polarization.展开更多
AIM To investigate whether M1 or M2 polarization contributes to the therapeutic effects of mesenchymal stem cells(MSCs) in acute hepatic failure(AHF).METHODS MSCs were transfused into rats with AHF induced by D-galact...AIM To investigate whether M1 or M2 polarization contributes to the therapeutic effects of mesenchymal stem cells(MSCs) in acute hepatic failure(AHF).METHODS MSCs were transfused into rats with AHF induced by D-galactosamine(DGal N). The therapeutic effects of MSCs were evaluated based on survival rate and hepatocyte proliferation and apoptosis. Hepatocyte regeneration capacity was evaluated by the expression of the hepatic progenitor surface marker epithelial cell adhesion molecule(Ep CAM). Macrophage polarization was analyzed by M1 markers [CD68,tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),inducible nitric oxide synthase(INOS)] and M2 markers [CD163,interleukin(IL)-4,IL-10,arginase-1(Arg-1)] in the survival and death groups after MSC transplantation.RESULTS The survival rate in the MSC-treated group was increased compared with the DPBS-treated control group(37.5% vs 10%). MSC treatment protected rats with AHF by reducing apoptotic hepatocytes and promoting hepatocyte regeneration. Immunohistochemical analysis showed that MSC treatment significantly increased the expression of Ep CAM compared with the control groups(P < 0.001). Expression of Ep CAM in the survival group was significantly up-regulated compared with the death group after MSC transplantation(P = 0.003). Transplantation of MSCs significantly improved the expression of CD163 and increased the gene expression of IL-10 and Arg-1 in the survival group. IL-4 concentrations were significantly increased compared to the death group after MSC transplantation(88.51 ± 24.51 pg/m L vs 34.61 ± 6.6 pg/m L,P < 0.001). In contrast,macrophages showed strong expression of CD68,TNF-α,and INOS in the death group. The concentration of IFN-γ was significantly increased compared to the survival group after MSC transplantation(542.11 ± 51.59 pg/m L vs 104.07 ± 42.80 pg/m L,P < 0.001).CONCLUSION M2 polarization contributes to the therapeutic effects of MSCs in AHF by altering levels of anti-inflammatory and pro-inflammatory factors.展开更多
Inflammation plays an important role in the pathological process of ischemic stroke,and systemic inflammation affects patient prognosis.As resident immune cells in the brain,microglia are significantly involved in imm...Inflammation plays an important role in the pathological process of ischemic stroke,and systemic inflammation affects patient prognosis.As resident immune cells in the brain,microglia are significantly involved in immune defense and tissue repair under various pathological conditions,including cerebral ischemia.Although the differentiation of M1 and M2 microglia is certainly oversimplified,changing the activation state of microglia appears to be an intriguing therapeutic strategy for cerebral ischemia.Recent evidence indicates that both mesenchymal stem cells(MSCs)and MSC-derived extracellular vesicles(EVs)regulate inflammation and modify tissue repair under preclinical stroke conditions.However,the precise mechanisms of these signaling pathways,especially in the context of the mutual interaction between MSCs or MSC-derived EVs and resident microglia,have not been sufficiently unveiled.Hence,this review summarizes the state-ofthe-art knowledge on MSC-and MSC-EV-mediated regulation of microglial activity under ischemic stroke conditions with respect to various signaling pathways,including cytokines,neurotrophic factors,transcription factors,and microRNAs.展开更多
Neural stem cell(NSC)transplantation is a promising strategy for replacing lost neurons following spinal cord injury.However,the survival and differentiation of transplanted NSCs is limited,possibly owing to the neuro...Neural stem cell(NSC)transplantation is a promising strategy for replacing lost neurons following spinal cord injury.However,the survival and differentiation of transplanted NSCs is limited,possibly owing to the neurotoxic inflammatory microenvironment.Because of the important role of glucose metabolism in M1/M2 polarization of microglia/macrophages,we hypothesized that altering the phenotype of microglia/macrophages by regulating the activity of aldose reductase(AR),a key enzyme in the polyol pathway of glucose metabolism,would provide a more beneficial microenvironment for NSC survival and differentiation.Here,we reveal that inhibition of host AR promoted the polarization of microglia/macrophages toward the M2 phenotype in lesioned spinal cord injuries.M2 macrophages promoted the differentiation of NSCs into neurons in vitro.Transplantation of NSCs into injured spinal cords either deficient in AR or treated with the AR inhibitor sorbinil promoted the survival and neuronal differentiation of NSCs at the injured spinal cord site and contributed to locomotor functional recovery.Our findings suggest that inhibition of host AR activity is beneficial in enhancing the survival and neuronal differentiation of transplanted NSCs and shows potential as a treatment of spinal cord injury.展开更多
背景:NOD样受体热蛋白结构域相关蛋白3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)炎性小体与脊髓损伤后的神经炎症密切相关,小胶质细胞极化和焦亡在其中发挥关键作用,靶向调控NLRP3有利于诱导小胶质细胞...背景:NOD样受体热蛋白结构域相关蛋白3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)炎性小体与脊髓损伤后的神经炎症密切相关,小胶质细胞极化和焦亡在其中发挥关键作用,靶向调控NLRP3有利于诱导小胶质细胞从M1促炎表型向M2抗炎表型极化和调节小胶质细胞焦亡,是一个有前景的治疗策略。目的:归纳NLRP3炎性小体在脊髓损伤后小胶质细胞中作用的分子机制以及治疗策略的研究进展。方法:检索PubMed、Web of Science和中国知网数据库,英文检索词为“spinal cord injury,NLRP3,microglia,polarization,pyroptosis”,中文检索词为“脊髓损伤,NLRP3,小胶质细胞,极化,焦亡,炎症”,按纳入和排除标准共纳入79篇文献进行总结。结果与结论:①目前,关于脊髓损伤复杂的发病机制尚未有统一定论,大量研究表明脊髓损伤与炎症因子和信号通路关系密切,以NLRP3炎性小体作为其发病机制和治疗突破口的相关研究也是当前的热点。②NLRP3炎性小体在脊髓损伤后的炎症反应、氧化应激和神经元恢复等起到关键作用。③小胶质细胞是脑和脊髓中的免疫细胞,是继发性脊髓损伤最重要的调节因子,脊髓损伤后小胶质细胞对内部环境作出调整,主要表现为极化及焦亡,产生大量炎症因子,阻碍脊髓损伤的神经再生和功能恢复,通过调控小胶质细胞表型变化,是治疗脊髓损伤的另一个关键因素。④NLRP3炎性小体与小胶质细胞密切相关,脊髓损伤后NLRP3炎性小体主要在小胶质细胞中表达,其会促进小胶质细胞向M1极化和促进促裂解蛋白D的产生,进一步破坏神经稳态,从而加重脊髓损伤的进展。⑤许多分子参与NLRP3炎性小体调控小胶质细胞,其中核转录因子κB及MAPK信号通路促进NLRP3炎性小体表达,其他信号通路抑制该炎性小体表达。⑥目前有大量的外源性分子及药物调控NLRP3炎性小体,临床应用前景广泛,已有相关药物处于临床试验阶段并取得良好疗效,如NLRP3特异性抑制剂MCC950,但如何精准控制靶向递送、减少对其他组织器官影响等关键问题亟需解决,随着研究的深入,未来有望在脊髓损伤治疗方式上作出新的突破。展开更多
Background and Aims:Acute liver failure(ALF)is a life-threatening clinical problem with limited treatment options.Administration of human umbilical cord mesenchymal stem cells(hUC-MSCs)may be a promising approach for ...Background and Aims:Acute liver failure(ALF)is a life-threatening clinical problem with limited treatment options.Administration of human umbilical cord mesenchymal stem cells(hUC-MSCs)may be a promising approach for ALF.This study aimed to explore the role of hUC-MSCs in the treat-ment of ALF and the underlying mechanisms.Methods:A mouse model of ALF was induced by lipopolysaccharide and d-galactosamine administration.The therapeutic effects of hUC-MSCs were evaluated by assessing serum enzyme activity,histological appearance,and cell apoptosis in liver tissues.The apoptosis rate was analyzed in AML12 cells.The levels of inflammatory cytokines and the phenotype of RAW264.7 cells co-cultured with hUC-MSCs were detected.The C-Jun N-terminal kinase/nuclear factor-kappa B signal-ing pathway was studied.Results:The hUC-MSCstreatment decreased the levels of serum alanine aminotransferase and aspartate aminotransferase,reduced pathological damage,alleviated hepatocyte apoptosis,and reduced mortality in vivo.The hUC-MSCs co-culture reduced the apoptosis rate of AML12 cells in vitro.Moreover,lipopolysaccharide-stimulated RAW264.7 cells had higher levels of tumor necrosis factor-α,interleukin-6,and interleukin-1β and showed more CD86-positive cells,whereas the hUC-MSCs co-culture reduced the levels of the three inflammatory cytokines and increased the ratio of CD206-positive cells.The hUC-MSCs treatment inhibited the activation of phosphorylated(p)-C-Jun N-terminal kinase and p-nuclear factor-kappa B not only in liver tissues but also in AML12and RAW264.7 cells co-cultured with hUC-MSCs.Conclusions:hUC-MSCs could alleviate ALF by regulating hepatocyte apoptosis and macrophage polarization,thus hUC-MSC-based cell therapy may be an alternative option for patients with ALF.展开更多
BACKGROUND Bone healing is a complex process involving early inflammatory immune regu-lation,angiogenesis,osteogenic differentiation,and biomineralization.Fracture repair poses challenges for orthopedic surgeons,neces...BACKGROUND Bone healing is a complex process involving early inflammatory immune regu-lation,angiogenesis,osteogenic differentiation,and biomineralization.Fracture repair poses challenges for orthopedic surgeons,necessitating the search for efficient healing methods.AIM To investigate the underlying mechanism by which hydrogel-loaded exosomes derived from bone marrow mesenchymal stem cells(BMSCs)facilitate the process of fracture healing.METHODS Hydrogels and loaded BMSC-derived exosome(BMSC-exo)gels were charac-terized to validate their properties.In vitro evaluations were conducted to assess the impact of hydrogels on various stages of the healing process.Hydrogels could recruit macrophages and inhibit inflammatory responses,enhance of human umbilical vein endothelial cell angiogenesis,and promote the osteogenic differen-tiation of primary cranial osteoblasts.Furthermore,the effect of hydrogel on fracture healing was confirmed using a mouse fracture model.RESULTS The hydrogel effectively attenuated the inflammatory response during the initial repair stage and subsequently facilitated vascular migration,promoted the formation of large vessels,and enabled functional vascularization during bone repair.These effects were further validated in fracture models.CONCLUSION We successfully fabricated a hydrogel loaded with BMSC-exo that modulates macrophage polarization and angiogenesis to influence bone regeneration.展开更多
Background:Ischemic stroke has been regarded as a major cause of disability and death around the world due to limited effective therapies.Accumulating evidence have shown that although microglia are polarized to an an...Background:Ischemic stroke has been regarded as a major cause of disability and death around the world due to limited effective therapies.Accumulating evidence have shown that although microglia are polarized to an anti-inflammatory M2 phenotype in the early stage of ischemia,they transform progressively into a proinflammatory M1 phenotype.Bone marrow-derived mesenchymal stem cells(BMSCs)may be used to treat ischemic injury through regulating the poststroke inflammatory response.However,the mechanism by which BMSCs can treat ischemic stroke remains unclarified.Objective:This study aimed to investigate whether BMSCs shift M1-to-M2 phenotype transformation of mi-croglia/macrophages and enhance neurogenesis in a rat transient middle cerebral artery occlusion(tMCAO)model.Methods:Ninety-minute tMCAO was applied to the rats,followed by reperfusion.BMSCs were transplanted into the rats via intravenous injection at 24 h after tMCAO.After being randomly divided into the sham group,the MCAO group,and the BMSCs group,the rats’behavior was assessed at 1,3,7,and 14 days following tM-CAO.qRT-PCR,double-immunofluorescence staining,and Western blot were performed at 3 and 14 days after tMCAO to determine M1/M2 polarization of microglia/macrophages.Neurogenesis was examined by double-immunofluorescence staining at 14 days after tMCAO.Expression of brain-derived neurotrophic factor(BDNF)was measured on the protein level by immunofluorescence staining at 3 and 14 days after tMCAO.Results:We found that BMSCs treatment promoted the recovery of neurological function after tMCAO,inhibited the expression of TNF𝛼,iNOS and CD16/32,which are markers of M1 microglia/macrophage,and enhanced the expression of IL10,TGF𝛽and CD206 that are markers of M2 microglia/macrophage.Moreover,BMSCs treatment promoted neurogenesis and M2-derived BDNF expression after tMCAO.Conclusion:It is indicated by the results that BMSCs modulate neuroinflammation and enhance neurogenesis,which could be due to transforming microglia/macrophages from the M1 polarization state towards M2 in a rat tMCAO model.展开更多
文摘BACKGROUND Bone marrow mesenchymal stem cells(BMSCs)are capable of shifting the microglia/macrophages phenotype from M1 to M2,contributing to BMSCsinduced brain repair.However,the regulatory mechanism of BMSCs on microglia/macrophages after ischemic stroke is unclear.Recent evidence suggests that mesencephalic astrocyte-derived neurotrophic factor(MANF)and plateletderived growth factor-AA(PDGF-AA)/MANF signaling regulate M1/M2 macrophage polarization.AIM To investigate whether and how MANF or PDGF-AA/MANF signaling influences BMSCs-mediated M2 polarization.METHODS We identified the secretion of MANF by BMSCs and developed transgenic BMSCs using a targeting small interfering RNA for knockdown of MANF expression.Using a rat middle cerebral artery occlusion(MCAO)model transplanted by BMSCs and BMSCs-microglia Transwell coculture system,the effect of BMSCsinduced downregulation of MANF expression on the phenotype of microglia/macrophages was tested by Western blot,quantitative reverse transcription-polymerase chain reaction,and immunofluorescence.Additionally,microglia were transfected with mimics of miR-30a*,which inuenced expression of X-box binding protein(XBP)1,a key transcription factor that synergized with activating transcription factor 6(ATF6)to govern MANF expression.We examined the levels of miR-30a*,ATF6,XBP1,and MANF after PDGF-AA treatment in the activated microglia.RESULTS Inhibition of MANF attenuated BMSCs-induced functional recovery and decreased M2 marker production,but increased M1 marker expression in vivo or in vitro.Furthermore,PDGF-AA treatment decreased miR-30a*expression,had no influence on the levels of ATF6,but enhanced expression of both XBP1 and MANF.CONCLUSION BMSCs-mediated MANF paracrine signaling,in particular the PDGF-AA/miR-30a*/XBP1/MANF pathway,synergistically mediates BMSCs-induced M2 polarization.
基金Supported by Liaoning Provincial Science and Technology Key Project for Translational Medicine,No.2014225020Outstanding Scientific Fund of Shengjing Hospital,No.201102Liaoning Provincial Science and Technology Key Project for Translational Medicine,No.2016509
文摘AIM To investigate whether M1 or M2 polarization contributes to the therapeutic effects of mesenchymal stem cells(MSCs) in acute hepatic failure(AHF).METHODS MSCs were transfused into rats with AHF induced by D-galactosamine(DGal N). The therapeutic effects of MSCs were evaluated based on survival rate and hepatocyte proliferation and apoptosis. Hepatocyte regeneration capacity was evaluated by the expression of the hepatic progenitor surface marker epithelial cell adhesion molecule(Ep CAM). Macrophage polarization was analyzed by M1 markers [CD68,tumor necrosis factor alpha(TNF-α),interferon-γ(IFN-γ),inducible nitric oxide synthase(INOS)] and M2 markers [CD163,interleukin(IL)-4,IL-10,arginase-1(Arg-1)] in the survival and death groups after MSC transplantation.RESULTS The survival rate in the MSC-treated group was increased compared with the DPBS-treated control group(37.5% vs 10%). MSC treatment protected rats with AHF by reducing apoptotic hepatocytes and promoting hepatocyte regeneration. Immunohistochemical analysis showed that MSC treatment significantly increased the expression of Ep CAM compared with the control groups(P < 0.001). Expression of Ep CAM in the survival group was significantly up-regulated compared with the death group after MSC transplantation(P = 0.003). Transplantation of MSCs significantly improved the expression of CD163 and increased the gene expression of IL-10 and Arg-1 in the survival group. IL-4 concentrations were significantly increased compared to the death group after MSC transplantation(88.51 ± 24.51 pg/m L vs 34.61 ± 6.6 pg/m L,P < 0.001). In contrast,macrophages showed strong expression of CD68,TNF-α,and INOS in the death group. The concentration of IFN-γ was significantly increased compared to the survival group after MSC transplantation(542.11 ± 51.59 pg/m L vs 104.07 ± 42.80 pg/m L,P < 0.001).CONCLUSION M2 polarization contributes to the therapeutic effects of MSCs in AHF by altering levels of anti-inflammatory and pro-inflammatory factors.
文摘Inflammation plays an important role in the pathological process of ischemic stroke,and systemic inflammation affects patient prognosis.As resident immune cells in the brain,microglia are significantly involved in immune defense and tissue repair under various pathological conditions,including cerebral ischemia.Although the differentiation of M1 and M2 microglia is certainly oversimplified,changing the activation state of microglia appears to be an intriguing therapeutic strategy for cerebral ischemia.Recent evidence indicates that both mesenchymal stem cells(MSCs)and MSC-derived extracellular vesicles(EVs)regulate inflammation and modify tissue repair under preclinical stroke conditions.However,the precise mechanisms of these signaling pathways,especially in the context of the mutual interaction between MSCs or MSC-derived EVs and resident microglia,have not been sufficiently unveiled.Hence,this review summarizes the state-ofthe-art knowledge on MSC-and MSC-EV-mediated regulation of microglial activity under ischemic stroke conditions with respect to various signaling pathways,including cytokines,neurotrophic factors,transcription factors,and microRNAs.
基金supported by the National Natural Science Foundation of China,Nos.81601056(to KZ),81901252(to QZ)Shaanxi Key Research and Development Program of China,No.2020SF-083(to KZ)+1 种基金Sanming Project of Medicine in Shenzhen of China,No.SZSM201911011(to SXW)the Key Laboratory of Spine and Spinal Cord Injury Repair and Regeneration(Tongji University,Ministry of Education)of China(to KZ).
文摘Neural stem cell(NSC)transplantation is a promising strategy for replacing lost neurons following spinal cord injury.However,the survival and differentiation of transplanted NSCs is limited,possibly owing to the neurotoxic inflammatory microenvironment.Because of the important role of glucose metabolism in M1/M2 polarization of microglia/macrophages,we hypothesized that altering the phenotype of microglia/macrophages by regulating the activity of aldose reductase(AR),a key enzyme in the polyol pathway of glucose metabolism,would provide a more beneficial microenvironment for NSC survival and differentiation.Here,we reveal that inhibition of host AR promoted the polarization of microglia/macrophages toward the M2 phenotype in lesioned spinal cord injuries.M2 macrophages promoted the differentiation of NSCs into neurons in vitro.Transplantation of NSCs into injured spinal cords either deficient in AR or treated with the AR inhibitor sorbinil promoted the survival and neuronal differentiation of NSCs at the injured spinal cord site and contributed to locomotor functional recovery.Our findings suggest that inhibition of host AR activity is beneficial in enhancing the survival and neuronal differentiation of transplanted NSCs and shows potential as a treatment of spinal cord injury.
文摘背景:NOD样受体热蛋白结构域相关蛋白3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)炎性小体与脊髓损伤后的神经炎症密切相关,小胶质细胞极化和焦亡在其中发挥关键作用,靶向调控NLRP3有利于诱导小胶质细胞从M1促炎表型向M2抗炎表型极化和调节小胶质细胞焦亡,是一个有前景的治疗策略。目的:归纳NLRP3炎性小体在脊髓损伤后小胶质细胞中作用的分子机制以及治疗策略的研究进展。方法:检索PubMed、Web of Science和中国知网数据库,英文检索词为“spinal cord injury,NLRP3,microglia,polarization,pyroptosis”,中文检索词为“脊髓损伤,NLRP3,小胶质细胞,极化,焦亡,炎症”,按纳入和排除标准共纳入79篇文献进行总结。结果与结论:①目前,关于脊髓损伤复杂的发病机制尚未有统一定论,大量研究表明脊髓损伤与炎症因子和信号通路关系密切,以NLRP3炎性小体作为其发病机制和治疗突破口的相关研究也是当前的热点。②NLRP3炎性小体在脊髓损伤后的炎症反应、氧化应激和神经元恢复等起到关键作用。③小胶质细胞是脑和脊髓中的免疫细胞,是继发性脊髓损伤最重要的调节因子,脊髓损伤后小胶质细胞对内部环境作出调整,主要表现为极化及焦亡,产生大量炎症因子,阻碍脊髓损伤的神经再生和功能恢复,通过调控小胶质细胞表型变化,是治疗脊髓损伤的另一个关键因素。④NLRP3炎性小体与小胶质细胞密切相关,脊髓损伤后NLRP3炎性小体主要在小胶质细胞中表达,其会促进小胶质细胞向M1极化和促进促裂解蛋白D的产生,进一步破坏神经稳态,从而加重脊髓损伤的进展。⑤许多分子参与NLRP3炎性小体调控小胶质细胞,其中核转录因子κB及MAPK信号通路促进NLRP3炎性小体表达,其他信号通路抑制该炎性小体表达。⑥目前有大量的外源性分子及药物调控NLRP3炎性小体,临床应用前景广泛,已有相关药物处于临床试验阶段并取得良好疗效,如NLRP3特异性抑制剂MCC950,但如何精准控制靶向递送、减少对其他组织器官影响等关键问题亟需解决,随着研究的深入,未来有望在脊髓损伤治疗方式上作出新的突破。
基金supported by the National Key Research and Development Program of China(2022YFC2304800)the Science and Technological Supports Project of Sichuan Province in China(2022YFS0094).
文摘Background and Aims:Acute liver failure(ALF)is a life-threatening clinical problem with limited treatment options.Administration of human umbilical cord mesenchymal stem cells(hUC-MSCs)may be a promising approach for ALF.This study aimed to explore the role of hUC-MSCs in the treat-ment of ALF and the underlying mechanisms.Methods:A mouse model of ALF was induced by lipopolysaccharide and d-galactosamine administration.The therapeutic effects of hUC-MSCs were evaluated by assessing serum enzyme activity,histological appearance,and cell apoptosis in liver tissues.The apoptosis rate was analyzed in AML12 cells.The levels of inflammatory cytokines and the phenotype of RAW264.7 cells co-cultured with hUC-MSCs were detected.The C-Jun N-terminal kinase/nuclear factor-kappa B signal-ing pathway was studied.Results:The hUC-MSCstreatment decreased the levels of serum alanine aminotransferase and aspartate aminotransferase,reduced pathological damage,alleviated hepatocyte apoptosis,and reduced mortality in vivo.The hUC-MSCs co-culture reduced the apoptosis rate of AML12 cells in vitro.Moreover,lipopolysaccharide-stimulated RAW264.7 cells had higher levels of tumor necrosis factor-α,interleukin-6,and interleukin-1β and showed more CD86-positive cells,whereas the hUC-MSCs co-culture reduced the levels of the three inflammatory cytokines and increased the ratio of CD206-positive cells.The hUC-MSCs treatment inhibited the activation of phosphorylated(p)-C-Jun N-terminal kinase and p-nuclear factor-kappa B not only in liver tissues but also in AML12and RAW264.7 cells co-cultured with hUC-MSCs.Conclusions:hUC-MSCs could alleviate ALF by regulating hepatocyte apoptosis and macrophage polarization,thus hUC-MSC-based cell therapy may be an alternative option for patients with ALF.
文摘BACKGROUND Bone healing is a complex process involving early inflammatory immune regu-lation,angiogenesis,osteogenic differentiation,and biomineralization.Fracture repair poses challenges for orthopedic surgeons,necessitating the search for efficient healing methods.AIM To investigate the underlying mechanism by which hydrogel-loaded exosomes derived from bone marrow mesenchymal stem cells(BMSCs)facilitate the process of fracture healing.METHODS Hydrogels and loaded BMSC-derived exosome(BMSC-exo)gels were charac-terized to validate their properties.In vitro evaluations were conducted to assess the impact of hydrogels on various stages of the healing process.Hydrogels could recruit macrophages and inhibit inflammatory responses,enhance of human umbilical vein endothelial cell angiogenesis,and promote the osteogenic differen-tiation of primary cranial osteoblasts.Furthermore,the effect of hydrogel on fracture healing was confirmed using a mouse fracture model.RESULTS The hydrogel effectively attenuated the inflammatory response during the initial repair stage and subsequently facilitated vascular migration,promoted the formation of large vessels,and enabled functional vascularization during bone repair.These effects were further validated in fracture models.CONCLUSION We successfully fabricated a hydrogel loaded with BMSC-exo that modulates macrophage polarization and angiogenesis to influence bone regeneration.
基金supported by the National Natural Sci-ence Foundation of China(Grant Nos.81274113,81873028,81903949)the Natural Science Foundation of Zhejiang Province(Grant No.LQ19H290004).
文摘Background:Ischemic stroke has been regarded as a major cause of disability and death around the world due to limited effective therapies.Accumulating evidence have shown that although microglia are polarized to an anti-inflammatory M2 phenotype in the early stage of ischemia,they transform progressively into a proinflammatory M1 phenotype.Bone marrow-derived mesenchymal stem cells(BMSCs)may be used to treat ischemic injury through regulating the poststroke inflammatory response.However,the mechanism by which BMSCs can treat ischemic stroke remains unclarified.Objective:This study aimed to investigate whether BMSCs shift M1-to-M2 phenotype transformation of mi-croglia/macrophages and enhance neurogenesis in a rat transient middle cerebral artery occlusion(tMCAO)model.Methods:Ninety-minute tMCAO was applied to the rats,followed by reperfusion.BMSCs were transplanted into the rats via intravenous injection at 24 h after tMCAO.After being randomly divided into the sham group,the MCAO group,and the BMSCs group,the rats’behavior was assessed at 1,3,7,and 14 days following tM-CAO.qRT-PCR,double-immunofluorescence staining,and Western blot were performed at 3 and 14 days after tMCAO to determine M1/M2 polarization of microglia/macrophages.Neurogenesis was examined by double-immunofluorescence staining at 14 days after tMCAO.Expression of brain-derived neurotrophic factor(BDNF)was measured on the protein level by immunofluorescence staining at 3 and 14 days after tMCAO.Results:We found that BMSCs treatment promoted the recovery of neurological function after tMCAO,inhibited the expression of TNF𝛼,iNOS and CD16/32,which are markers of M1 microglia/macrophage,and enhanced the expression of IL10,TGF𝛽and CD206 that are markers of M2 microglia/macrophage.Moreover,BMSCs treatment promoted neurogenesis and M2-derived BDNF expression after tMCAO.Conclusion:It is indicated by the results that BMSCs modulate neuroinflammation and enhance neurogenesis,which could be due to transforming microglia/macrophages from the M1 polarization state towards M2 in a rat tMCAO model.
