RNA-sequencing of liver tissue from wild type and Gramd1c knockout mice fed with high and low cholesterol diet. RNA-sequencing of liver tissue from wild type and Gramd1c knockout mice fed with high and low cholesterol diet

The Aster-C protein (encoded by the Gramd1c gene) is an endoplasmic reticulum (ER) resident protein that has been reported to transport cholesterol from the plasma membrane to the ER . Although there is a clear role for the closely-related Aster-B protein in cholesterol transport and downstream esterification in the adrenal gland, the specific role for Aster-C in tissue cholesterol homeostasis is not well understood. Here, we have examined whole body cholesterol balance in mice globally lacking Aster-C under low or high dietary cholesterol conditions.transport and metabolism under divergent dietary cholesterol conditions. These results strongly suggest that Aster-C alone is not sufficient to control whole body cholesterol balance, but can modestly impact circulating cortisol and bile acid levels when dietary cholesterol is limited. Overall design: Liver tissue mRNA profiles of GRAMD1C wild type and knockout mice fed with high and low cholesterol diet for 4 weeks

Aster-C蛋白（Aster-C protein）由Gramd1c基因编码，为内质网（endoplasmic reticulum, ER）驻留蛋白，已有研究证实其可介导胆固醇从质膜向内质网转运。尽管同源性极高的Aster-B蛋白在肾上腺的胆固醇转运及下游酯化过程中发挥明确功能，但Aster-C在组织胆固醇稳态中的具体作用仍未明确。本研究针对低、高膳食胆固醇条件下全身敲除Aster-C的小鼠，分析了其全身胆固醇平衡状况，并探究了不同膳食胆固醇条件下的胆固醇转运与代谢过程。研究结果强烈提示，仅依靠Aster-C不足以维持全身胆固醇稳态，但在膳食胆固醇摄入受限的情况下，其可轻度影响循环皮质醇与胆汁酸水平。实验设计：对饲喂高、低胆固醇饲料4周的GRAMD1C野生型与敲除型小鼠的肝脏组织进行mRNA表达谱分析。