Quantitation of Gene Expression by Real-Time PCR Disproves a “Retroviral Hypothesis” for Childhood-Onset Diabetes Mellitus
Quantitation of Gene Expression by Real-Time PCR Disproves a “Retroviral Hypothesis” for Childhood-Onset Diabetes Mellitus
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实时 PCR 定量基因表达反驳了儿童期糖尿病的“逆转录病毒假说”
作者：
I. Knerr;R. Repp;J. Dötsch;N. Gratzki;J. Hänze;T. Kapellen;W. Rascher
胰岛素依赖型糖尿病（insulin dependent diabetes mellitus，IDDM）患儿存在慢性自身免疫性β细胞破坏，原因不明，可能是超抗原或逆转录病毒内源性基因所致。最近，一种新的内源性逆转录病毒命名为IDDMK1，222被提出编码这样的候选自身免疫基因在1型糖尿病。因此，我们分析了IDDMK 1，222基因在55名健康儿童和55名糖尿病儿童（包括11名急性发病的患者）外周血白细胞和血浆中的表达。在我们的研究中，我们应用了一种改进的定量和高度特异性的实时PCR检测。与以前通过常规PCR获得的数据相反，IDDMK1，222基因表达在糖尿病和非糖尿病个体之间没有差异。因此，我们认为IDDMK1，222是人类基因组中普遍存在的内源性逆转录病毒元件，但不是IDDM的候选自身免疫基因，特别是在儿童期发病的疾病中。实时PCR被证明是一种高度敏感和特异的方法，用于检测和定量非常低的mRNA量，因此将是有用的儿科研究中的特殊要求，处理非常低的标本量。
Children with insulin-dependent diabetes mellitus (IDDM) suffer from a chronic autoimmune β cell destruction of unknown origin, maybe due to superantigens or retroviral endogenous genes. Recently, a novel endogenous retrovirus designated as IDDMK1,222 was proposed to encode for such a candidate autoimmune gene in type 1 diabetes. We therefore analyzed the expression of IDDMK1,222 genes in peripheral blood leukocytes and plasma from 55 healthy children and 55 diabetic children including 11 patients with acute disease onset. In our study we applied an improved quantitative and highly specific real-time PCR assay. In contrast to previous data obtained by conventional PCR, IDDMK1,222 gene expression did not differ between diabetic and nondiabetic individuals. For this reason, we propose that IDDMK1,222 is an ubiquitous endogenous retroviral element in the human genome but not a candidate autoimmune gene for IDDM, especially in childhood-onset disease. Real-time PCR proved to be a highly sensitive and specific method for detection and quantitation of very low amounts of mRNA and will thereby be useful regarding the special demands in pediatric studies dealing with very low amounts of specimen.