Lee B, Srinivasan M, Aalinkeel R, Patel M S, Laychock S G
Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, 14214, USA.
Metabolism. 2001 Feb;50(2):200-6. doi: 10.1053/meta.2001.17714.
Mitochondrial adenosine triphosphate (ATP) generation plays a major role in insulin secretion in pancreatic islet beta cells. The relationship between age and nutritional status of the islet and mitochondrial gene messenger RNA (mRNA) expression was investigated. Three animal groups were studied: infant (12-day-old) rats fed either mother's milk or a high carbohydrate (HC) diet; young (2 to 4-month-old) rats; and old (12 to 14-month-old) rats. The expression of mitochondrial cytochrome oxidase (CYO) (subunits I, II, and III), beta-nicotinamide adenine dinucleotide, reduced form dehydrogenase subunit 4 (NADH-DH4), and ATP synthase (subunit 6) (ATP-SYN6) mRNAs was characterized by semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The mitochondrial gene mRNAs were identified in each of the groups of rat islets and in RINm5F cells. CYO-II mRNA expression in young and old rat pancreatic islets was 12.7- and 8.2-fold higher, respectively, compared with the level in infant rat islets. The expression of NADH-DH4 and ATP-SYN6 mRNAs was 47% and 40% lower, respectively, in young rat islets compared with the level in infant rat islets. CYO-I, CYO-III, and cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GPDH) mRNA expression did not differ between experimental groups. Artificial rearing of infant rat pups on a HC diet for 8 days lead to a 3.3-fold increase in islet CYO-II mRNA expression compared with mother-fed pups. However, glucose (11 mmol/L) stimulation of cultured isolated islets from young and old rats for 4 days failed to affect the expression level of mitochondrial gene mRNAs. Thus, aging affected the differential expression of CYO-II, NADH-DH4, and ATP-SYN6 mRNAs in rat islets. CYO-II mRNA expression was modulated only in infant rat islets after in vivo administration of carbohydrate.
线粒体三磷酸腺苷（ATP）生成在胰岛β细胞的胰岛素分泌中起主要作用。研究了胰岛的年龄与营养状况和线粒体基因信使核糖核酸（mRNA）表达之间的关系。研究了三组动物：用母乳或高碳水化合物（HC）饮食喂养的幼龄（12日龄）大鼠；青年（2至4月龄）大鼠；以及老龄（12至14月龄）大鼠。通过半定量逆转录聚合酶链反应（RT-PCR）对线粒体细胞色素氧化酶（CYO）（亚基I、II和III）、β-烟酰胺腺嘌呤二核苷酸还原型脱氢酶亚基4（NADH-DH4）和ATP合酶（亚基6）（ATP-SYN6）mRNA的表达进行了表征。在大鼠胰岛的每组以及RINm5F细胞中均鉴定出线粒体基因mRNA。与幼龄大鼠胰岛中的水平相比，青年和老龄大鼠胰岛中CYO-II mRNA的表达分别高12.7倍和8.2倍。与幼龄大鼠胰岛中的水平相比，青年大鼠胰岛中NADH-DH4和ATP-SYN6 mRNA的表达分别低47%和40%。实验组之间CYO-I、CYO-III和细胞质甘油醛-3-磷酸脱氢酶（GPDH）mRNA的表达没有差异。与由母鼠喂养的幼鼠相比，用HC饮食人工饲养幼龄大鼠幼崽8天导致胰岛CYO-II mRNA表达增加3.3倍。然而，用葡萄糖（11 mmol/L）刺激培养的青年和老龄大鼠分离胰岛4天未能影响线粒体基因mRNA的表达水平。因此，衰老影响大鼠胰岛中CYO-II、NADH-DH4和ATP-SYN6 mRNA的差异表达。在体内给予碳水化合物后，仅在幼龄大鼠胰岛中调节了CYO-II mRNA的表达。
