影响胆固醇在肠道吸收的相关蛋白

胆固醇在肠道吸收转运过程中，尼曼-匹克C1型类似蛋白1（Niemann-Pick C1 Like1，NPCIL1）介导了胆固醇的吸收，同时有协调ATP-结合盒转运体（ATP-binding cassette，ABC）G5和ABCG8的作用；胆固醇从质膜转运到内质网，通过酰基辅酶A-胆固醇酰基转移酶（acyl coenzyme A—cholesterol acyltransferase，ACAT）调节胆固醇的酯化速率，进而参与合成乳糜微粒，这个过程依赖脱辅基蛋白B（apoproteinB，apoB）、微粒体甘油三酯转移蛋白（microsomal triglyceride transfer protein，MTP）和内质网跨膜激酶（IRE1）β的活性。特异的小囊泡携带这些乳糜微粒到细胞的基底外侧膜，进入淋巴系统。另外未被ACAT酯化的胆固醇一部分通过ABCG5／G8返回肠道，另一部分通过ABCAl介导出基底外侧膜进入血浆。本文就调节胆固醇吸收相关蛋白及其调节机制的研究进展做一综述。

The Relevant Proteins in Intestinal Cholesterol Absorption

During the process of intestinal cholesterol absorption, NPC1 L1 mediated the uptake of cholesterol, and modified absorption overdose in coordination with ABCGS/gS. Cholesterol was transported to Endoplasmic Reticulum （ER）, where its rate of esterification was regulated by ACAT. Then, these esterified cholesterol participated in the synthesis of chylomicrons, which, however, depended on activities of apoB, MTP and IRE113. Chylomicrons were transported to basolateral membranes by specific vesicles for excretion. Finally, the ripe chylomicrons were transported to lymphatic system. Moreover, some unesterified cholesterols were transported back to intestine via ABCGS/G8, and others were mediated into blood from basolateral membrane by ABCA1. This review concerned relevant proteins and mechanisms of cholesterol absorption.