The genetic association of the transcription factor NPAT with glycemic response to metformin involves regulation of fuel selection.
The genetic association of the transcription factor NPAT with glycemic response to metformin involves regulation of fuel selection.
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DOI：
10.1371/journal.pone.0253533
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发表时间：
2021
期刊：
影响因子：
3.7
通讯作者：
Sutherland C
中科院分区：
文献类型：
--
作者：
Chen C;Gallagher JR;Tarlton J;van Aalten L;Bray SE;Ashford MLJ;McCrimmon RJ;Pearson ER;McNeilly AD;Sutherland C
双胍类药物二甲双胍是2型糖尿病的首选治疗药物，尽管二甲双胍临床疗效的基础机制仍然存在很多争议，部分原因是患者对二甲双胍的反应存在相当大的差异。通过基因型识别不良反应者可以避免不必要的治疗，并为潜在的作用机制提供线索。GWAS在含有NPAT（核蛋白，共济失调-毛细血管扩张基因座）和ATM（共济失调-毛细血管扩张突变）基因的基因座上鉴定了与二甲双胍治疗成功相关的SNP。这意味着基因序列决定了影响二甲双胍作用的后续生物学功能。因此，我们修改了NPAT在永生化细胞系、原代小鼠肝细胞和小鼠组织中的表达，并使用共聚焦显微镜、免疫印迹和免疫细胞化学分析了二甲双胍作用的结果。此外，我们对npat杂合子基因敲除小鼠的代谢表型进行了表征，并建立了胰岛素抵抗发生后二甲双胍的反应。NPAT蛋白定位于几种细胞类型的离散位点的细胞核中，但在永生化细胞模型中NPAT的过度表达或耗尽并不改变细胞对双胍的反应。相比之下，二甲双胍对呼吸交换率（RER）的调节在缺乏npat一个等位基因的动物中完全丧失。二甲双胍对糖耐量受损的纠正也减少了，但是在npat杂合子小鼠中没有发现其他代谢异常或对二甲双胍的反应。总之，我们提供了检测NPAT的方法学进展，证明NPAT mRNA水平的轻微降低（20-40%）影响二甲双胍对RER的调节，并提出在GWAS中观察到的NPAT SNP与二甲双胍反应之间的关联可能是由于二甲双胍对细胞燃料使用的修饰丧失。
The biguanide, metformin, is the first-choice therapeutic agent for type-2 diabetes, although the mechanisms that underpin metformin clinical efficacy remain the subject of much debate, partly due to the considerable variation in patient response to metformin. Identification of poor responders by genotype could avoid unnecessary treatment and provide clues to the underlying mechanism of action. GWAS identified SNPs associated with metformin treatment success at a locus containing the NPAT (nuclear protein, ataxia-telangiectasia locus) and ATM (ataxia-telangiectasia mutated) genes. This implies that gene sequence dictates a subsequent biological function to influence metformin action. Hence, we modified expression of NPAT in immortalized cell lines, primary mouse hepatocytes and mouse tissues, and analysed the outcomes on metformin action using confocal microscopy, immunoblotting and immunocytochemistry. In addition, we characterised the metabolic phenotype of npat heterozygous knockout mice and established the metformin response following development of insulin resistance. NPAT protein was localised in the nucleus at discrete loci in several cell types, but over-expression or depletion of NPAT in immortalised cell models did not change cellular responses to biguanides. In contrast, metformin regulation of respiratory exchange ratio (RER) was completely lost in animals lacking one allele of npat. There was also a reduction in metformin correction of impaired glucose tolerance, however no other metabolic abnormalities, or response to metformin, were found in the npat heterozygous mice. In summary, we provide methodological advancements for the detection of NPAT, demonstrate that minor reductions in NPAT mRNA levels (20–40%) influence metformin regulation of RER, and propose that the association between NPAT SNPs and metformin response observed in GWAS, could be due to loss of metformin modification of cellular fuel usage.
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影响因子：
8.2
作者：
Rena, Graham;Pearson, Ewan R.;Sakamoto, Kei
通讯作者：
Sakamoto, Kei
影响因子：
2.6
作者：
Gong L;Goswami S;Giacomini KM;Altman RB;Klein TE
通讯作者：
Klein TE
影响因子：
20.3
作者：
Saarinen, Silva;Aavikko, Mervi;Aaltonen, Lauri A.
通讯作者：
Aaltonen, Lauri A.
DOI：
10.1111/dme.13037
发表时间：
2016-03
期刊：
Diabetic medicine : a journal of the British Diabetic Association
影响因子：
--
作者：
Connelly PJ;Smith N;Chadwick R;Exley AR;Shneerson JM;Pearson ER
通讯作者：
Pearson ER
影响因子：
5.3
作者：
DeRan, Michael;Pulvino, Mary;Zhao, Jiyong
通讯作者：
Zhao, Jiyong