Abnormalities in insulin metabolism, characteristic of T2DM, are among the major factors thought to mechanistically influence the onset of AD. These abnormalities are thought to play a role in AD via their influence o...Abnormalities in insulin metabolism, characteristic of T2DM, are among the major factors thought to mechanistically influence the onset of AD. These abnormalities are thought to play a role in AD via their influence on the synthesis and degradation of Aβ and as a consequence of the cascade of neuronal alterations resulting from the effects of danger/alarm signals from oligomeric amyloid species. Additionally, recent studies have indicated that certain signal transduction pathways downstream of the InsR may also promote the generation of Aβ peptides by modulating the cleavage of the parent Aβ precursor protein (AβPP) at the γ-secretase site, a cleavage site necessary for Aβ amyloidogenicity. Glucose homeostasis is critical for energy generation, neuronal maintenance, neurogenesis, neurotransmitter regulation, cell survival and synaptic plasticity. It also plays a key role in cognitive function. In an insulin resistance condition, there is a reduced sensitivity to insulin resulting in hyperinsulinemia;this condition persists for several years before becoming full blown diabetes. Toxic levels of insulin negatively influence neuronal function and survival, and elevation of peripheral insulin concentration acutely increases its cerebrospinal fluid (CSF) concentration. Peripheral hyperinsulinemia correlates with an abnormal removal of the amyloid beta peptide (Aβ) and an increase of tau hyperphosphorylation as a result of augmented cdk5 and GSK3β activities. This leads to cellular cascades that trigger a neurodegenerative phenotype and decline in cognitive function. Chronic peripheral hyperinsulinemia results in a reduction of insulin transport across the BBB and reduced insulin signaling in brain, altering all of insulin’s actions, including its anti-apoptotic effect. However, the increase in brain insulin levels resulting from its peripheral administration at optimal doses has shown a cognition enhancing effect on patient with AD.展开更多
目的:探讨绞股蓝对海马注射Aβ1-40大鼠脑内细胞周期蛋白异常表达和钙稳态变化的影响。方法:动物随机分为绞股蓝组、模型组、对照组。运用淀粉样β蛋白双侧海马注射,模拟阿尔茨海默病脑内Aβ对神经系统的损害。Y型迷宫测试大鼠学习记忆...目的:探讨绞股蓝对海马注射Aβ1-40大鼠脑内细胞周期蛋白异常表达和钙稳态变化的影响。方法:动物随机分为绞股蓝组、模型组、对照组。运用淀粉样β蛋白双侧海马注射,模拟阿尔茨海默病脑内Aβ对神经系统的损害。Y型迷宫测试大鼠学习记忆能力,免疫组织化学染色和积分吸光度分析检测细胞周期蛋白A、B1(cyc linA、cyc lin B1),Fura-2/AM-荧光法测定海马细胞内Ca2+含量;并对绞股蓝组大鼠给予绞股蓝皂苷灌胃,观察其对AD大鼠上述各项指标变化的影响。结果:Aβ1-40海马注射大鼠学习记忆能力明显低于对照组(P<0.05),脑内细胞周期蛋白A、B1蛋白水平明显高于对照组,海马神经元内Ca2+含量显著高于对照组;而给予绞股蓝在一定程度上能改善大鼠学习记忆能力,降低cyc lin A、cyc lin B1蛋白和Ca2+含量的水平(P<0.05)。结论:绞股蓝对Aβ引起的动物学习记忆能力减退、海马神经元内异常表达细胞周期蛋白和钙稳态失衡有一定的逆转作用。展开更多
文摘Abnormalities in insulin metabolism, characteristic of T2DM, are among the major factors thought to mechanistically influence the onset of AD. These abnormalities are thought to play a role in AD via their influence on the synthesis and degradation of Aβ and as a consequence of the cascade of neuronal alterations resulting from the effects of danger/alarm signals from oligomeric amyloid species. Additionally, recent studies have indicated that certain signal transduction pathways downstream of the InsR may also promote the generation of Aβ peptides by modulating the cleavage of the parent Aβ precursor protein (AβPP) at the γ-secretase site, a cleavage site necessary for Aβ amyloidogenicity. Glucose homeostasis is critical for energy generation, neuronal maintenance, neurogenesis, neurotransmitter regulation, cell survival and synaptic plasticity. It also plays a key role in cognitive function. In an insulin resistance condition, there is a reduced sensitivity to insulin resulting in hyperinsulinemia;this condition persists for several years before becoming full blown diabetes. Toxic levels of insulin negatively influence neuronal function and survival, and elevation of peripheral insulin concentration acutely increases its cerebrospinal fluid (CSF) concentration. Peripheral hyperinsulinemia correlates with an abnormal removal of the amyloid beta peptide (Aβ) and an increase of tau hyperphosphorylation as a result of augmented cdk5 and GSK3β activities. This leads to cellular cascades that trigger a neurodegenerative phenotype and decline in cognitive function. Chronic peripheral hyperinsulinemia results in a reduction of insulin transport across the BBB and reduced insulin signaling in brain, altering all of insulin’s actions, including its anti-apoptotic effect. However, the increase in brain insulin levels resulting from its peripheral administration at optimal doses has shown a cognition enhancing effect on patient with AD.
文摘目的:探讨绞股蓝对海马注射Aβ1-40大鼠脑内细胞周期蛋白异常表达和钙稳态变化的影响。方法:动物随机分为绞股蓝组、模型组、对照组。运用淀粉样β蛋白双侧海马注射,模拟阿尔茨海默病脑内Aβ对神经系统的损害。Y型迷宫测试大鼠学习记忆能力,免疫组织化学染色和积分吸光度分析检测细胞周期蛋白A、B1(cyc linA、cyc lin B1),Fura-2/AM-荧光法测定海马细胞内Ca2+含量;并对绞股蓝组大鼠给予绞股蓝皂苷灌胃,观察其对AD大鼠上述各项指标变化的影响。结果:Aβ1-40海马注射大鼠学习记忆能力明显低于对照组(P<0.05),脑内细胞周期蛋白A、B1蛋白水平明显高于对照组,海马神经元内Ca2+含量显著高于对照组;而给予绞股蓝在一定程度上能改善大鼠学习记忆能力,降低cyc lin A、cyc lin B1蛋白和Ca2+含量的水平(P<0.05)。结论:绞股蓝对Aβ引起的动物学习记忆能力减退、海马神经元内异常表达细胞周期蛋白和钙稳态失衡有一定的逆转作用。
