Elevated expression of αA- and αB-crystallins in streptozotocin-induced diabetic rat
Elevated expression of αA- and αB-crystallins in streptozotocin-induced diabetic rat
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DOI：
10.1016/j.abb.2005.09.021
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发表时间：
2005-12-15
影响因子：
3.9
通讯作者：
Reddy, GB
中科院分区：
文献类型：
--
作者：
Kumar, PA;Haseeb, A;Reddy, GB
α-晶状体蛋白是眼透镜的主要蛋白质，由两个亚基α A和α B组成。其中，α B-晶状体蛋白已被证明广泛存在于非晶状体组织中，而α A-晶状体蛋白主要是晶状体特异性的。尽管在各种应激和病理条件下α B-晶状体蛋白的表达升高，但其生理意义仍不清楚。有研究认为α B-晶状体蛋白基因的表达与氧化应激有关。已知在不受控制的糖尿病期间持续的高血糖症会引起氧化应激，氧化应激与糖尿病的各种继发性并发症有关。因此，α A-和α B-晶体蛋白在链脲佐菌素（STZ）诱导的糖尿病Wistar-NIN大鼠的各种组织中的表达进行了研究，通过RT-PCR和免疫印迹。虽然在研究中检查的广泛组织中注意到α B-晶状体蛋白的表达，但仅在透镜和视网膜中检测到α A-晶状体蛋白的表达。有趣的是，与对照组大鼠相比，糖尿病大鼠的透镜、心脏、肌肉和脑中α B-晶状体蛋白表达升高，但脂肪组织中α B-晶状体蛋白表达降低。糖尿病大鼠视网膜α A-晶体蛋白表达增加。增加的氧化应激似乎是糖尿病大鼠组织中α A-和α B-晶状体蛋白表达增强的主要刺激，α-晶状体蛋白表达升高可能对代谢应激具有保护作用。有趣的是，给糖尿病大鼠喂食姜黄素（一种膳食抗氧化剂）减弱了α B-晶状体蛋白的表达增强。结果表明，在某些组织中α-晶体蛋白的表达升高可能对糖尿病并发症的病理生理学有影响。(c)2005年爱思唯尔公司All rights reserved.
alpha-Crystallin, a predominant protein of the ocular lens, is composed of two subunits, alpha A and alpha B. Of these, alpha B-crystallin has been shown to present widely in non-lenticular tissues while alpha A-crystallin is largely lens-specific. Although, expression of alpha B-crystallin is elevated under various stress and pathological conditions, yet its physiological significance remained unknown. Some studies suggest that the expression of alpha B-crystallin gene is related to oxidative stress. Persistent hyperglycemia during uncontrolled diabetes is known to cause oxidative stress, which has been implicated in various secondary complications of diabetes. Hence, expression of alpha A- and alpha B-crystallins in various tissues of streptozotocin (STZ)-induced diabetic Wistar-NIN rats was investigated by RT-PCR and immunoblotting. While expression of alpha B-crystallin was noted in the wide range of tissues examined in the study, alpha A-crystallin expression was detected only in lens and retina. Interestingly, alpha B-crystallin expression was elevated in lens, heart, muscle, and brain, but decreased in adipose tissue of diabetic rats compared to control rats. alpha A-Crystallin expression was increased in retina of diabetic rat. Increased oxidative stress appears to be a major stimulus for the enhanced expression of alpha A- and alpha B-crystallins in the tissues of diabetic rats and elevated expression of alpha-crystallin may have a protective role against metabolic stress. Interestingly, feeding of curcumin, a dietary antioxidant, to diabetic rats attenuated the enhanced expression of alpha B-crystallin. The results indicate that elevated expression of alpha-crystallins in some tissues may have implications in pathophysiology of diabetic complications. (c) 2005 Elsevier Inc. All rights reserved.