Institute of Experimental Biomedicine, University Hospital Würzburg, Würzburg, Germany.
Division of Hepatology, University Hospital Würzburg, Würzburg, Germany.
Am J Physiol Gastrointest Liver Physiol. 2024 Jul 1;327(1):G25-G35. doi: 10.1152/ajpgi.00222.2023. Epub 2024 May 7.
Cholesterol is essential for the stability and architecture of the plasma membrane and a precursor of bile acids and steroid hormones in mammals. Excess dietary cholesterol uptake leads to hypercholesterolemia and atherosclerosis and plays a role in cancer development. The role of actin-binding scaffolding protein LIM and SH3 protein 1 (LASP1) in cholesterol trafficking has not been investigated previously. Cholesterol levels, its uptake, and excretion were studied in mice deficient for low-density lipoprotein receptor and ( mice) upon feeding a high-fat diet, and in LASP1-knockdown, differentiated human intestinal epithelial CaCo-2 cells. When compared with diet-fed control mice, mice displayed a reduction in serum cholesterol levels. Mechanistically, we identified a new role of LASP1 in controlling the translocation of the intestinal cholesterol transporter Niemann-Pick C1-like 1 (NPC1L1) to the apical cell surface, which was limited in LASP1-knockdown human CaCo-2 enterocytes and in the intestine of compared with mice, linked to LASP1-pAKT signaling but not CDC42 activation. In line, a reduction in cholesterol reabsorption was noted in LASP1-knockdown CaCo-2 cells in vitro, and an enhanced cholesterol excretion via the feces was observed in mice. These data uncover a novel function of Lasp1 in cholesterol trafficking, promoting cholesterol reabsorption in the intestine. Targeting LASP1 locally could thus represent a novel targeting strategy to ameliorate hypercholesterolemia and associated diseases. We here uncovered LASP1 as a novel regulator of the shuttling of the sterol transporter NPC1L1 to the cell surface in enterocytes to control cholesterol absorption. Accordingly, LASP1-deficient mice displayed lowered serum cholesterol levels under dietary cholesterol supplementation.
胆固醇对于血浆膜的稳定性和结构至关重要,也是哺乳动物胆汁酸和类固醇激素的前体。过量的饮食胆固醇摄取会导致高胆固醇血症和动脉粥样硬化,并在癌症发展中发挥作用。以前尚未研究过肌动蛋白结合支架蛋白 LIM 和 SH3 蛋白 1(LASP1)在胆固醇转运中的作用。在喂食高脂肪饮食的缺乏低密度脂蛋白受体和( 小鼠)的小鼠以及敲低 LASP1 的分化人肠上皮细胞 CaCo-2 中研究了胆固醇水平、摄取和排泄。与饮食喂养的 对照组相比, 小鼠的血清胆固醇水平降低。从机制上讲,我们确定了 LASP1 在控制肠道胆固醇转运蛋白 NPC1L1(尼曼-匹克 C1 样 1)向细胞表面顶侧易位中的新作用,该作用在敲低 LASP1 的人 CaCo-2 肠细胞和 与 小鼠相比,与 LASP1-pAKT 信号传导有关,但与 CDC42 激活无关。与此一致,在体外敲低 LASP1 的 CaCo-2 细胞中观察到胆固醇再吸收减少,而 小鼠中通过粪便排泄的胆固醇增加。这些数据揭示了 Lasp1 在胆固醇转运中的新功能,促进了肠道中胆固醇的吸收。局部靶向 LASP1 可能是改善高胆固醇血症和相关疾病的新靶向策略。我们在这里发现 LASP1 是固醇转运蛋白 NPC1L1 在肠细胞中向细胞表面易位的新型调节剂,以控制胆固醇吸收。因此,在饮食补充胆固醇的情况下,缺乏 LASP1 的小鼠的血清胆固醇水平降低。