目的通过动物和体外培养的软骨细胞观察糖基化终末产物(advanced glycation end products,AGEs)对软骨细胞线粒体功能的损伤作用,并探讨相关机制。方法小鼠膝关节腔直接注射AGEs,番红O-固绿染色评估病理学改变;JC-1检测线粒体膜电位ΔΨ...目的通过动物和体外培养的软骨细胞观察糖基化终末产物(advanced glycation end products,AGEs)对软骨细胞线粒体功能的损伤作用,并探讨相关机制。方法小鼠膝关节腔直接注射AGEs,番红O-固绿染色评估病理学改变;JC-1检测线粒体膜电位ΔΨm;Western blot检测腺苷酸活化蛋白激酶(adenosine monophosphate-activated protein kinase,AMPK)、过氧化物酶体增殖物激活受体γ辅助活化因子α(peroxisome proliferator-activated receptorγcoactivator-1α,PGC-1α)、去乙酰化酶3(sirtuin3,SIRT3)及基质金属蛋白酶(matrix metalloproteinase,MMP)-3、-13的表达。结果膝关节注射AGEs 8周后,小鼠出现骨关节炎样病理改变;在体外培养的软骨细胞中,AGEs可以损伤线粒体功能,同时p-AMPK、SIRT3和PGC-1α的表达减少;给予AMPK选择性激动剂AICAR则可以拮抗AGEs的上述作用,而特异性敲除SIRT3或PGC-1α后,AICAR此拮抗作用减弱。结论AGEs可能通过下调AMPK-PGC-1α-SIRT3信号通路诱导软骨细胞线粒体功能损伤,进而促进OA病变。展开更多
Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experime...Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experiments involving 48 and 32 healthy 60-week-old Hy-Line Brown hens,respectively.The hens exhibited either dark(L*=51.99±2.08)or light(L*=64.12±3.02)brown eggshell colors.In Exp.1,light brown-shelled hens were fed a basal diet(Lb group),while dark brown-shelled hens received either a basal diet(Db group)or a basal diet with 10 mg/kg ammonium metavanadate(Dbv group)for 20 d.In Exp.2,light brown-shelled hens received either a basal diet(Lbc group)or a basal diet supplemented with 200 mg/kg resveratrol(Lbr group)for 12 weeks.Results Compared to the Db group,eggshell L*values increased,and PpIX concentrations in both eggshell and uterus decreased in Dbv and Lb groups.These groups also showed oxidative stress,as indicated by reduced hepatic T-SOD and CAT activities.Uterine redox status changes were further confirmed by increased T-AOC level(Dbv)and reduced CAT gene expression(Lb).These redox disturbances led to reduced expression of ND4 and COX1 mt DNA,decreased ATP production and CS activity,along with upregulation of IR,PI3K,HK,and PK gene expression,reflecting altered mitochondrial energy metabolism.Notably,the SIRT1/PGC-1αsignaling cascade and its downstream target ALAS1 were significantly downregulated at both mRNA and protein levels in Dbv and Lb groups.Compared to the Lbc group,the Lbr group exhibited higher antioxidant capacity by increasing hepatic CAT activity and uterine T-SOD and GSH-Px activities,and reducing MDA levels.Moreover,the Lbr group restored mitochondrial function and PpIX biosynthesis by upregulating ND4 and COX1 mt DNA,CS and SDHA gene expression,and SIRT1/PGC-1α/ALAS1 signaling,while downregulating LDH activity and the expression of IR and PI3K,thereby alleviating eggshell color fading.Conclusion Oxidative stress induces eggshell depigmentation by impairing mitochondrial function and downregulating the SIRT1/PGC-1α/ALAS1 pathway,leading to reduced PpIX biosynthesis.Specifically,vanadium-induced or endogenous oxidative stress disrupts mitochondrial energy metabolism and suppresses key components of this pathway,while resveratrol alleviates oxidative damage and restores mitochondrial function and ALAS1-driven PpIX synthesis through reactivation of the SIRT1/PGC-1αaxis.展开更多
基金financially supported by the National Natural Science Foundation of China(32322078)the earmarked fund for the China Agriculture Research System(CARS-40)+1 种基金the China Postdoctoral Science Foundation(grant no.2024M763615)the Agricultural Science and Technology Innovation Program(ASTIP)of CAAS。
文摘Background This study investigated the molecular mechanisms by which redox status regulates protoporphyrin IX(PpIX)biosynthesis and eggshell coloration in brown-shelled laying hens.This study consisted of two experiments involving 48 and 32 healthy 60-week-old Hy-Line Brown hens,respectively.The hens exhibited either dark(L*=51.99±2.08)or light(L*=64.12±3.02)brown eggshell colors.In Exp.1,light brown-shelled hens were fed a basal diet(Lb group),while dark brown-shelled hens received either a basal diet(Db group)or a basal diet with 10 mg/kg ammonium metavanadate(Dbv group)for 20 d.In Exp.2,light brown-shelled hens received either a basal diet(Lbc group)or a basal diet supplemented with 200 mg/kg resveratrol(Lbr group)for 12 weeks.Results Compared to the Db group,eggshell L*values increased,and PpIX concentrations in both eggshell and uterus decreased in Dbv and Lb groups.These groups also showed oxidative stress,as indicated by reduced hepatic T-SOD and CAT activities.Uterine redox status changes were further confirmed by increased T-AOC level(Dbv)and reduced CAT gene expression(Lb).These redox disturbances led to reduced expression of ND4 and COX1 mt DNA,decreased ATP production and CS activity,along with upregulation of IR,PI3K,HK,and PK gene expression,reflecting altered mitochondrial energy metabolism.Notably,the SIRT1/PGC-1αsignaling cascade and its downstream target ALAS1 were significantly downregulated at both mRNA and protein levels in Dbv and Lb groups.Compared to the Lbc group,the Lbr group exhibited higher antioxidant capacity by increasing hepatic CAT activity and uterine T-SOD and GSH-Px activities,and reducing MDA levels.Moreover,the Lbr group restored mitochondrial function and PpIX biosynthesis by upregulating ND4 and COX1 mt DNA,CS and SDHA gene expression,and SIRT1/PGC-1α/ALAS1 signaling,while downregulating LDH activity and the expression of IR and PI3K,thereby alleviating eggshell color fading.Conclusion Oxidative stress induces eggshell depigmentation by impairing mitochondrial function and downregulating the SIRT1/PGC-1α/ALAS1 pathway,leading to reduced PpIX biosynthesis.Specifically,vanadium-induced or endogenous oxidative stress disrupts mitochondrial energy metabolism and suppresses key components of this pathway,while resveratrol alleviates oxidative damage and restores mitochondrial function and ALAS1-driven PpIX synthesis through reactivation of the SIRT1/PGC-1αaxis.
