DNA2,a multifunctional enzyme with structure-specific nuclease,5'-to-3'helicase,and DNA-dependent ATPase activities,plays a pivotal role in the cellular response to DNA damage.However,its involvement in cerebr...DNA2,a multifunctional enzyme with structure-specific nuclease,5'-to-3'helicase,and DNA-dependent ATPase activities,plays a pivotal role in the cellular response to DNA damage.However,its involvement in cerebral ischemia/reperfusion(I/R)injury remains to be elucidated.This study investigated the involvement of DNA2 in cerebral I/R injury using conditional knockout(cKO)mice(Nestin-Cre)subjected to middle cerebral artery occlusion(MCAO),an established model of cerebral I/R.Results demonstrated a gradual up-regulation of DNA2 expression,peaking at 72 h post-MCAO.Notably,DNA2 cKO mice exhibited more pronounced brain injury,neurological deficits,and neuronal apoptosis within the penumbra following MCAO.Additionally,DNA2 expression was elevated in an oxygen-glucose deprivation/reoxygenation(OGD/R)cell culture model,and DNA2 knockdown(KD)exacerbated neuronal apoptosis and oxidative stress.Transcriptome analysis of ischemic penumbra tissues via RNA sequencing revealed significant down-regulation of Homer1 in DNA2 cKO mice.Furthermore,in vitro experiments demonstrated that overexpression of Homer1a ameliorated DNA2 KD-induced neuronal apoptosis.Collectively,these findings demonstrate that DNA2 deficiency exacerbates cerebral I/R injury through the down-regulation of Homer1a,highlighting a novel regulatory axis in ischemic neuroprotection.展开更多
Homer1a是由中枢神经系统即刻早期基因(immediate early genes,IEG)编码的支架蛋白质,广泛的临床及基础研究表明Homer1a不仅与多种神经精神疾病的发病有关,也是多种抗抑郁治疗方案的关键蛋白质。抑郁症的发病与1型代谢型谷氨酸受体(meta...Homer1a是由中枢神经系统即刻早期基因(immediate early genes,IEG)编码的支架蛋白质,广泛的临床及基础研究表明Homer1a不仅与多种神经精神疾病的发病有关,也是多种抗抑郁治疗方案的关键蛋白质。抑郁症的发病与1型代谢型谷氨酸受体(metabotropic glutamate receptor,mGluR1/5)的表达和可用性降低,N-甲基-D-天冬氨酸受体(N-methyl-D-aspartate receptor,NMDAR)的功能障碍所致的突触可塑性失调相关。Homer1a对mGluR1/5的作用具有高度特异性。Homer1a过表达可通过增加突触后膜mGluR1/5的表达和可用性,调节突触后膜的离子型谷氨酸受体NMDAR和α-氨基-3-羟基-5-甲基-4-异噁唑丙酸受体(α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor,AMPAR),调节突触可塑性,最终发挥抗抑郁作用。Homer1a在突触活动的调节中发挥中心作用,因此了解Homer1a发挥作用的机制能为研究靶向Homer1a蛋白的抗抑郁药物提供新思路。展开更多
Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in ...Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homerla on NLRP3inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models we re constructed using C57BL/6J and Homer1^(flox/-)/Homerla^(+/-)/Nestin-Cre^(+/-)mice with elevated IOP-induced retinal ischemia/repe rfusion injury.For in vitro expe riments,the oxygen-glucose deprivation/repe rfusion injury model was constructed with M uller cells.We found that Homerla ove rexpression amelio rated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homerla knockdown promoted NF-κB P65^(Ser536)activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1βand inte rleukin-18.The opposite results we re observed with Homerla ove rexpression.Finally,the combined administration of Homerla protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1^(flox/-)Homer1a^(+/-)/Nestin-Cre^(+/-)mice and apoptosis in M uller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and M uller cells via the caspase-8/NF-KB P65/NLRP3 pathway after I/R injury.展开更多
基金supported by the National Natural Science Foundation of China (32070979)Shenzhen Science and Technology Program (JCYJ20220530161604009,JCYJ20240813150734043)+3 种基金Key Research and Development Program of Shaanxi (2024SF,YBXM,050)Fundamental Research Funds for the Central Universities (31020190QD004,3102019YX01001)Double First-Class Project of China Pharmaceutical University (CPUQNJC22_02)Global Pharmaceutical Development Alliance Plan of China Pharmaceutical University (1302090024-05)。
文摘DNA2,a multifunctional enzyme with structure-specific nuclease,5'-to-3'helicase,and DNA-dependent ATPase activities,plays a pivotal role in the cellular response to DNA damage.However,its involvement in cerebral ischemia/reperfusion(I/R)injury remains to be elucidated.This study investigated the involvement of DNA2 in cerebral I/R injury using conditional knockout(cKO)mice(Nestin-Cre)subjected to middle cerebral artery occlusion(MCAO),an established model of cerebral I/R.Results demonstrated a gradual up-regulation of DNA2 expression,peaking at 72 h post-MCAO.Notably,DNA2 cKO mice exhibited more pronounced brain injury,neurological deficits,and neuronal apoptosis within the penumbra following MCAO.Additionally,DNA2 expression was elevated in an oxygen-glucose deprivation/reoxygenation(OGD/R)cell culture model,and DNA2 knockdown(KD)exacerbated neuronal apoptosis and oxidative stress.Transcriptome analysis of ischemic penumbra tissues via RNA sequencing revealed significant down-regulation of Homer1 in DNA2 cKO mice.Furthermore,in vitro experiments demonstrated that overexpression of Homer1a ameliorated DNA2 KD-induced neuronal apoptosis.Collectively,these findings demonstrate that DNA2 deficiency exacerbates cerebral I/R injury through the down-regulation of Homer1a,highlighting a novel regulatory axis in ischemic neuroprotection.
基金supported by the Youth Development Project of Air Force Military Medical University,No.21 QNPY072Key Project of Shaanxi Provincial Natural Science Basic Research Program,No.2023-JC-ZD-48(both to FF)。
文摘Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homerla on NLRP3inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models we re constructed using C57BL/6J and Homer1^(flox/-)/Homerla^(+/-)/Nestin-Cre^(+/-)mice with elevated IOP-induced retinal ischemia/repe rfusion injury.For in vitro expe riments,the oxygen-glucose deprivation/repe rfusion injury model was constructed with M uller cells.We found that Homerla ove rexpression amelio rated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homerla knockdown promoted NF-κB P65^(Ser536)activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1βand inte rleukin-18.The opposite results we re observed with Homerla ove rexpression.Finally,the combined administration of Homerla protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1^(flox/-)Homer1a^(+/-)/Nestin-Cre^(+/-)mice and apoptosis in M uller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and M uller cells via the caspase-8/NF-KB P65/NLRP3 pathway after I/R injury.
