目的:探讨先天性甲状腺功能减退症(congenital hypothyroidism,CH)大鼠海马中Ca^(2+)/钙调蛋白依赖性蛋白激酶Ⅳ(Ca^(2+)/calmodulin-dependent protein kinaseⅣ,CAMK4)及早期生长反应蛋白3(early growth response protein 3,EGR3)信...目的:探讨先天性甲状腺功能减退症(congenital hypothyroidism,CH)大鼠海马中Ca^(2+)/钙调蛋白依赖性蛋白激酶Ⅳ(Ca^(2+)/calmodulin-dependent protein kinaseⅣ,CAMK4)及早期生长反应蛋白3(early growth response protein 3,EGR3)信号轴对神经元树突发育的影响。方法:1日龄、7日龄及21日龄SD大鼠制备CH模型,分为CH组与对照组。采用转录组测序、q-PCR、Western blot分别检测CAMK4与EGR3的表达情况,细胞免疫荧光观察神经元树突生长情况。结果:(1)对照组海马组织CAMK4及EGR3的蛋白表达呈时间依赖性上升,CH组的表达则显著低于对照组(P <0.05);(2)原代海马神经元中敲降CAMK4后,EGR3的表达相应降低,同时海马神经元树突平均长度较对照组减小;(3)CH原代海马神经元给予三碘甲腺原氨酸(3,5,3′-triiodothyronine,T3)刺激后,CAMK4的蛋白表达水平呈时间依赖性上升。结论:甲状腺激素缺乏会导致大鼠海马CAMK4及EGR3表达降低,从而抑制神经元树突的发育,表明CAMK4-EGR3信号轴可能在CH大鼠海马神经发育异常中发挥重要作用。展开更多
Autosomal dominant polycystic kidney disease(ADPKD)is characterized by progressive enlargement of fluid-filled cysts,causing nephron loss and a decline in renal function.Mammalian target of rapamycin(mTOR)is overactiv...Autosomal dominant polycystic kidney disease(ADPKD)is characterized by progressive enlargement of fluid-filled cysts,causing nephron loss and a decline in renal function.Mammalian target of rapamycin(mTOR)is overactive in cyst-lining cells and contributes to abnormal cell proliferation and cyst enlargement;however,the mechanism for mTOR stimulation remains unclear.We discovered that calcium/calmodulin(CaM)dependent kinase IV(CaMK4),a multifunctional kinase,is overexpressed in the kidneys of ADPKD patients and PKD mouse models.In human ADPKD cells,CaMK4 knockdown reduced mTOR abundance and the phosphorylation of ribosomal protein S6 kinase(S6K),a downstream target of mTOR.Pharmacologic inhibition of CaMK4 with KN-93 reduced phosphorylated S6K and S6 levels and inhibited cell proliferation and in vitro cyst formation of ADPKD cells.Moreover,inhibition of calcium/CaM-dependent protein kinase kinase-βand CaM,two key upstream regulators of CaMK4,also decreased mTOR signaling.The effects of KN-93 were independent of the liver kinase B1-adenosine monophosphate-activated protein kinase(AMPK)pathway,and the combination of KN-93 and metformin,an AMPK activator,had additive inhibitory effects on mTOR signaling and in vitro cyst growth.Our data suggest that increased CaMK4 expression and activity contribute to mTOR signaling and the proliferation of cystic cells of ADPKD kidneys.展开更多
Genistein has a neuroprotective effect in Alzheimer＇s disease, but its mechanism of action needs further clarification. Accumulating evidence suggests that excessive phosphorylation of tau protein causes production o...Genistein has a neuroprotective effect in Alzheimer＇s disease, but its mechanism of action needs further clarification. Accumulating evidence suggests that excessive phosphorylation of tau protein causes production of neurofibrillary tangles, which is one of the main pathological characteristics of Alzheimer＇s disease, and tau protein can be phosphorylated by calcium/calmodulin dependent protein kinase IV （CAMK4）. After 7 days of pre-administration of genistein （90 mg/kg）, an Alzheimer＇s disease rat model was established using an intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-β peptide （25-35）. The rat was then continu- ously administered genistein （90 mg/kg） for 42 days. The Morris water maze test, western blotting and hematoxylin-eosin staining results showed that genistein significantly decreased the escape latency and increased the number of times crossing the platform, reduced p-tau, CALM, CAMKK1 and p-CAMK4 protein levels in the hippocampus, and alleviated hippocampal neuron damage. These findings indicate that genistein may play a neuroprotective role in Alzheimer＇s disease through regulating CAMK4 to modulate tau hyperphosphorylation. Key展开更多
文摘目的:探讨先天性甲状腺功能减退症(congenital hypothyroidism,CH)大鼠海马中Ca^(2+)/钙调蛋白依赖性蛋白激酶Ⅳ(Ca^(2+)/calmodulin-dependent protein kinaseⅣ,CAMK4)及早期生长反应蛋白3(early growth response protein 3,EGR3)信号轴对神经元树突发育的影响。方法:1日龄、7日龄及21日龄SD大鼠制备CH模型,分为CH组与对照组。采用转录组测序、q-PCR、Western blot分别检测CAMK4与EGR3的表达情况,细胞免疫荧光观察神经元树突生长情况。结果:(1)对照组海马组织CAMK4及EGR3的蛋白表达呈时间依赖性上升,CH组的表达则显著低于对照组(P <0.05);(2)原代海马神经元中敲降CAMK4后,EGR3的表达相应降低,同时海马神经元树突平均长度较对照组减小;(3)CH原代海马神经元给予三碘甲腺原氨酸(3,5,3′-triiodothyronine,T3)刺激后,CAMK4的蛋白表达水平呈时间依赖性上升。结论:甲状腺激素缺乏会导致大鼠海马CAMK4及EGR3表达降低,从而抑制神经元树突的发育,表明CAMK4-EGR3信号轴可能在CH大鼠海马神经发育异常中发挥重要作用。
基金National Institute of Diabetes and Digestive and Kidney Disease(R01DK081579 to D.P.W.)fellowship grants from the PKD Foundation(to Y.Z.)Kansas Idea Network of Biomedical Research Excellence(K-INBRE,P20 GM103418 to Y.Z.).
文摘Autosomal dominant polycystic kidney disease(ADPKD)is characterized by progressive enlargement of fluid-filled cysts,causing nephron loss and a decline in renal function.Mammalian target of rapamycin(mTOR)is overactive in cyst-lining cells and contributes to abnormal cell proliferation and cyst enlargement;however,the mechanism for mTOR stimulation remains unclear.We discovered that calcium/calmodulin(CaM)dependent kinase IV(CaMK4),a multifunctional kinase,is overexpressed in the kidneys of ADPKD patients and PKD mouse models.In human ADPKD cells,CaMK4 knockdown reduced mTOR abundance and the phosphorylation of ribosomal protein S6 kinase(S6K),a downstream target of mTOR.Pharmacologic inhibition of CaMK4 with KN-93 reduced phosphorylated S6K and S6 levels and inhibited cell proliferation and in vitro cyst formation of ADPKD cells.Moreover,inhibition of calcium/CaM-dependent protein kinase kinase-βand CaM,two key upstream regulators of CaMK4,also decreased mTOR signaling.The effects of KN-93 were independent of the liver kinase B1-adenosine monophosphate-activated protein kinase(AMPK)pathway,and the combination of KN-93 and metformin,an AMPK activator,had additive inhibitory effects on mTOR signaling and in vitro cyst growth.Our data suggest that increased CaMK4 expression and activity contribute to mTOR signaling and the proliferation of cystic cells of ADPKD kidneys.
基金supported by the National Natural Science Foundation of China,No.81202941 and 81574040the Key Project Foundation of Oversea Visiting and Research for the Excellent Young and Middle-aged Faculties in Universities of Anhui Province in China,No.gxfx ZD2016119+1 种基金the Key Project Foundation of Natural Science Research in Universities of Anhui Province in China,No.KJ2016A406the Key Project Foundation of Support Program for the Excellent Young Faculties in Universities of Anhui Province in China,No.gxyq ZD2016138
文摘Genistein has a neuroprotective effect in Alzheimer＇s disease, but its mechanism of action needs further clarification. Accumulating evidence suggests that excessive phosphorylation of tau protein causes production of neurofibrillary tangles, which is one of the main pathological characteristics of Alzheimer＇s disease, and tau protein can be phosphorylated by calcium/calmodulin dependent protein kinase IV （CAMK4）. After 7 days of pre-administration of genistein （90 mg/kg）, an Alzheimer＇s disease rat model was established using an intraperitoneal injection of D-galactose combined with an intracerebral injection of amyloid-β peptide （25-35）. The rat was then continu- ously administered genistein （90 mg/kg） for 42 days. The Morris water maze test, western blotting and hematoxylin-eosin staining results showed that genistein significantly decreased the escape latency and increased the number of times crossing the platform, reduced p-tau, CALM, CAMKK1 and p-CAMK4 protein levels in the hippocampus, and alleviated hippocampal neuron damage. These findings indicate that genistein may play a neuroprotective role in Alzheimer＇s disease through regulating CAMK4 to modulate tau hyperphosphorylation. Key
