Somatotrope GHRH/GH/IGF-1 axis at the crossroads between immunosenescence and frailty
Somatotrope GHRH/GH/IGF-1 axis at the crossroads between immunosenescence and frailty
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DOI：
10.1111/nyas.12857
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发表时间：
2015-01-01
期刊：
影响因子：
--
通讯作者：
Martens, Henri J.
中科院分区：
文献类型：
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作者：
Bodart, Gwennaelle;Goffinet, Lindsay;Martens, Henri J.
免疫衰老的特征是免疫力随着年龄的增长而发生复杂的变化，可能与老年人的虚弱综合征有关，导致对最低限度的攻击反应不足。功能衰退（I）例如，丧失进行日常生活活动的能力）与虚弱和生理储备减少有关，并且是老年患者住院治疗的常见结果。免疫衰老和虚弱之间的联系已被探索，20个免疫学参数，包括胰岛素样生长因子-1（IGF-1），胸腺生成和端粒长度，被证明是受影响的老年患者的功能下降。IGF-1和胸腺输出之间有很强的关系。IGF-1，生长激素（GH）的介质，随后显示，诱导白细胞介素-7分泌培养的原代人胸腺上皮细胞。我们正在探索的压力假说，其中一个急性应激源被用来作为脆弱易感性的证据。GH可以抵消应激诱导的类固醇的有害免疫抑制作用。在非应激条件下，免疫衰老系统保留生理反应，而在应激条件下，免疫衰老和生长激素轴缺陷的结合可能导致功能下降。
Immunosenescence, characterized by complex modifications of immunity with age, could be related to frailty syndrome in elderly individuals, leading to an inadequate response to minimal aggression. Functional decline (i. e., the loss of ability to perform activities of daily living) is related to frailty and decreased physiological reserves and is a frequent outcome of hospitalization in older patients. Links between immunosenescence and frailty have been explored and 20 immunological parameters, including insulin-like growth factor-1 (IGF-1), thymopoeisis, and telomere length, were shown to be affected in elderly patients with functional decline. A strong relationship between IGF-1 and thymic ouput was evidenced. IGF-1, a mediator of growth hormone (GH), was subsequently shown to induce interleukin-7 secretion in cultured primary human thymic epithelial cells. We are exploring the stress hypothesis in which an acute stressor is used as the discriminator of frailty susceptibility. GH can counteract the deleterious immunosuppressive effects of stress-induced steroids. Under nonstress conditions, the immunosenescent system preserves physiological responses, while under stress conditions, the combination of immunosenescence and a defect in the somatotrope axis might lead to functional decline.