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
Background SIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this proce...Background SIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this process are unclear. Methods The effects of SIRT3 on the regulation of oxidative stress and insulin resistance in skeletal muscle were evaluated in vitro. Differentiated L6 skeletal muscle cells were treated with 750 pmol/L palmitic acid to induce insulin resistance. SIRT3 was knocked down and overexpressed in L6 cells. SIRT3, nuclear factor kappa-light-chain-enhancer of activated B cells （NF-KB） p65, c-Jun N-terminal kinase 1 （JNK1）, and superoxide dismutase 2 （SOD2） were evaluated by Western blotting. Results Over expression of SIRT3 increased glucose uptake and decreased ROS production in L6-1R cells as well as in L6 cells. Knock-down of SIRT3 induced increased production of ROS while decreased glucose uptake in both L6 and L6- IR cells, and these effects were reversed by N-acetyI-L-cysteine （NAC）. Metformin increased the expression of SIRT3 （1.5- fold） and SOD2 （2-fold） while down regulating NF-KB p65 （1.5-fold） and JNK1 （1.5-fold）. Knockdown of SIRT3 （P〈0.05） reversed the metformin-induced decreases in NF-KB p65 and JNK1 and the metformin-induced increase in SOD2 （P〈0.05）. Conclusions Upregulated SIRT3 is involved in the pharmacological mechanism by which metformin promotes glucose uptake. Additionally, SIRT3 may function as an important regulator of oxidative stress and a new alternative approach for targeting insulin resistance-related diseases.展开更多
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.
文摘Background SIRT3 is an important regulator in cell metabolism, and recent studies have shown that it may be involved in the pharmacological effects of metformin. However, the molecular mechanisms underlying this process are unclear. Methods The effects of SIRT3 on the regulation of oxidative stress and insulin resistance in skeletal muscle were evaluated in vitro. Differentiated L6 skeletal muscle cells were treated with 750 pmol/L palmitic acid to induce insulin resistance. SIRT3 was knocked down and overexpressed in L6 cells. SIRT3, nuclear factor kappa-light-chain-enhancer of activated B cells （NF-KB） p65, c-Jun N-terminal kinase 1 （JNK1）, and superoxide dismutase 2 （SOD2） were evaluated by Western blotting. Results Over expression of SIRT3 increased glucose uptake and decreased ROS production in L6-1R cells as well as in L6 cells. Knock-down of SIRT3 induced increased production of ROS while decreased glucose uptake in both L6 and L6- IR cells, and these effects were reversed by N-acetyI-L-cysteine （NAC）. Metformin increased the expression of SIRT3 （1.5- fold） and SOD2 （2-fold） while down regulating NF-KB p65 （1.5-fold） and JNK1 （1.5-fold）. Knockdown of SIRT3 （P〈0.05） reversed the metformin-induced decreases in NF-KB p65 and JNK1 and the metformin-induced increase in SOD2 （P〈0.05）. Conclusions Upregulated SIRT3 is involved in the pharmacological mechanism by which metformin promotes glucose uptake. Additionally, SIRT3 may function as an important regulator of oxidative stress and a new alternative approach for targeting insulin resistance-related diseases.
