Role of ZAC1 in transient neonatal diabetes mellitus and glucose metabolism

• 作者: Anke Hoffmann Dietmar Spengler
• 来源期刊: 世界生物化学杂志：英文版（电子版）
• 学科: 医学
• 关键词: DIABETES MELLITUS ZAC1 Transient NEONATAL DIABETES MELLITUS 1 GENOMIC IMPRINTING Insulin Glucose Target genes TAILORED therapy
• 年，卷（期）: 2015,（3）
• 页码范围: 95-109
• 页数: 15页
• 分类号: R722.1

摘要

Transient neonatal diabetes mellitus 1(TNDM1) is a rare genetic disorder representing with severe neonatal hyperglycaemia followed by remission within one and a half year and adolescent relapse with type 2 diabetes in half of the patients. Genetic defects in TNDM1 comprise uniparental isodisomy of chromosome 6, duplication of the minimal TNDM1 locus at 6q24, or relaxation of genomically imprinted ZAC1 /HYMAI. Whereas the function of HYMAI, a non-coding m RNA, is still unidentified, biochemical and molecular studies show that zinc finger protein 1 regulating apoptosis and cell cycle arrest(ZAC1) behaves as a factor with versatile transcriptional functions dependent on binding to specific GC-rich DNA motives and interconnected regulation of recruited coactivator activities. Genome-wide expression profiling enabled the isolation of a number of Zac1 target genes known to regulate different aspects of β-cell function and peripheral insulin sensitivity. Among these, upregulation of Pparγ and Tcf4 impairs insulinsecretion and β-cell proliferation. Similarly, Zac1-mediated upregulation of Socs3 may attenuate β-cell proliferation and survival by inhibition of growth factor signalling. Additionally, Zac1 directly represses Pac1 and Rasgrf1 with roles in insulin secretion and β-cell proliferation. Collectively, concerted dysregulation of these target genes could contribute to the onset and course of TNDM1. Interestingly, Zac1 overexpression in β-cells spares the effects of stimulatory G-protein signaling on insulin secretion and raises the prospect for tailored treatments in relapsed TNDM1 patients. Overall, these results suggest that progress on the molecular and cellular foundations of monogenetic forms of diabetes can advance personalized therapy in addition to deepening the understanding of insulin and glucose metabolism in general.