目的:探讨膜肾方对特发性膜性肾病大鼠血浆诱导损伤足细胞的干预作用及其机制。方法:建立特发性膜性肾病大鼠模型,用肝素钠作为抗凝剂收集其血浆样品并诱导足细胞损伤,分对照组、模型组、膜肾方组、膜肾方+C3a受体(C3aR)拮抗剂组、C3aR...目的:探讨膜肾方对特发性膜性肾病大鼠血浆诱导损伤足细胞的干预作用及其机制。方法:建立特发性膜性肾病大鼠模型,用肝素钠作为抗凝剂收集其血浆样品并诱导足细胞损伤,分对照组、模型组、膜肾方组、膜肾方+C3a受体(C3aR)拮抗剂组、C3aR拮抗剂组。采用Western blotting检测各组足细胞C3aR、磷脂酶A2受体(PLA2R)、磷酸化细胞外信号调节激酶1/2(p-ERK1/2)、磷酸化细胞浆型磷脂酶A2(p-cPLA2)蛋白表达水平;酶联免疫吸附试验(ELISA)检测上清液C3a表达水平;Real-time PCR测定Synaptopodin mRNA、C3aR m RNA、PLA2R mRNA表达水平;细胞计数试剂盒-8(CCK-8)检测各组足细胞活力。结果:与对照组比较,模型组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均升高,上清液C3a水平升高,Synaptopodin m RNA水平下降,C3aR mRNA、PLA2R mRNA水平升高,足细胞活力下降,差异均有统计学意义(P<0.01);与模型组比较,膜肾方组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均下降,上清液C3a水平下降,Synaptopodin m RNA水平升高,C3aR mRNA、PLA2R mRNA水平下降,足细胞活力改善,差异均有统计学意义(P<0.01);与膜肾方组比较,膜肾方+C3aR拮抗剂组及C3aR拮抗剂组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均下降,上清液C3a水平下降,Synaptopodin mRNA水平升高,C3aR m RNA、PLA2R mRNA水平下降,足细胞活力改善,膜肾方+C3aR拮抗剂组更明显,差异均有统计学意义(P<0.01)。结论:膜肾方可能通过调控C3a/C3aR通路,下调PLA2R水平,稳定足细胞骨架,改善足细胞活力,从而发挥对足细胞的保护作用。展开更多
Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive as...Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.展开更多
文摘目的:探讨膜肾方对特发性膜性肾病大鼠血浆诱导损伤足细胞的干预作用及其机制。方法:建立特发性膜性肾病大鼠模型,用肝素钠作为抗凝剂收集其血浆样品并诱导足细胞损伤,分对照组、模型组、膜肾方组、膜肾方+C3a受体(C3aR)拮抗剂组、C3aR拮抗剂组。采用Western blotting检测各组足细胞C3aR、磷脂酶A2受体(PLA2R)、磷酸化细胞外信号调节激酶1/2(p-ERK1/2)、磷酸化细胞浆型磷脂酶A2(p-cPLA2)蛋白表达水平;酶联免疫吸附试验(ELISA)检测上清液C3a表达水平;Real-time PCR测定Synaptopodin mRNA、C3aR m RNA、PLA2R mRNA表达水平;细胞计数试剂盒-8(CCK-8)检测各组足细胞活力。结果:与对照组比较,模型组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均升高,上清液C3a水平升高,Synaptopodin m RNA水平下降,C3aR mRNA、PLA2R mRNA水平升高,足细胞活力下降,差异均有统计学意义(P<0.01);与模型组比较,膜肾方组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均下降,上清液C3a水平下降,Synaptopodin m RNA水平升高,C3aR mRNA、PLA2R mRNA水平下降,足细胞活力改善,差异均有统计学意义(P<0.01);与膜肾方组比较,膜肾方+C3aR拮抗剂组及C3aR拮抗剂组足细胞C3aR、PLA2R、p-ERK1/2、p-cPLA2表达水平均下降,上清液C3a水平下降,Synaptopodin mRNA水平升高,C3aR m RNA、PLA2R mRNA水平下降,足细胞活力改善,膜肾方+C3aR拮抗剂组更明显,差异均有统计学意义(P<0.01)。结论:膜肾方可能通过调控C3a/C3aR通路,下调PLA2R水平,稳定足细胞骨架,改善足细胞活力,从而发挥对足细胞的保护作用。
基金supported by the National Natural Science Foundation of China(82071362 and 82270669)Key Project of the Regional Joint Fund of Guangdong Province(2023B1515120077)+3 种基金Basic Research Program of Shenzhen Science and Technology Innovation Commission(JCYJ20210324123001003 and JCYJ20220530144801003)Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research(ZDSYS20230626091402006)the Innovation and Entrepreneurship Training Program for College Students,Sun Yat-sen University(20242150)the Leading Innovation and Entrepreneurship Team Program of Zhejiang Province,China(2023R01005).
文摘Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.
