Aster-dependent nonvesicular transport facilitates dietary cholesterol uptake
Alessandra Ferrari, Emily Whang, Xiao Xu, John P. Kennelly, Beatriz Romartínez-Alonso, Julia J. Mack, Thomas A. Weston, Kai Chen, Young-Jae Kim, Marcus J. Tol, Lara Bideyan, Alexander Nguyen, Yajing Gao, Liujuan Cui, Alexander H. Bedard, Jaspreet Sandhu, Stephen D. Lee, Louise Fairall, Kevin J. Williams, Wenxin Song, Priscilla Munguia, Robert A. Russell, Martı́n G. Martı́n, Michael E. Jung, Haibo Jiang, John W. R. Schwabe, Stephen G. Young, Peter Tontonoz
Abstract
Intestinal absorption is an important contributor to systemic cholesterol homeostasis. Niemann-Pick C1 Like 1 (NPC1L1) assists in the initial step of dietary cholesterol uptake, but how cholesterol moves downstream of NPC1L1 is unknown. We show that Aster-B and Aster-C are critical for nonvesicular cholesterol movement in enterocytes. Loss of NPC1L1 diminishes accessible plasma membrane (PM) cholesterol and abolishes Aster recruitment to the intestinal brush border. Enterocytes lacking Asters accumulate PM cholesterol and show endoplasmic reticulum cholesterol depletion. Aster-deficient mice have impaired cholesterol absorption and are protected against diet-induced hypercholesterolemia. Finally, the Aster pathway can be targeted with a small-molecule inhibitor to manipulate cholesterol uptake. These findings identify the Aster pathway as a physiologically important and pharmacologically tractable node in dietary lipid absorption.