Intestinal KLHL12 is dispensable for lipid absorption and chylomicron metabolism.

Abstract

Kelch-like protein 12 (KLHL12) has been shown to regulate coat complex II (COPII)-mediated endoplasmic reticulum (ER)-to-Golgi trafficking of large cargos carrying procollagen or apolipoprotein B-100 containing very-low-density lipoprotein (VLDL). It is known that lipid absorption and chylomicron metabolism in enterocytes are dependent on apolipoprotein B-48 (ApoB48) and COPII-mediated trafficking. This study aimed to investigate whether KLHL12 in the intestine regulates dietary lipid absorption, chylomicron assembly, and metabolic phenotypes in mice. We generated Klhl12 intestinal-specific knockout (IKO) mice and assessed the impact of its deficiency on lipid absorption and Western diet (WD)-induced obesity in both male and female mice. We examined lipid absorption in vivo by acute oil gavage and fasting/high-fat diet (HFD) refeeding. Under chow diet feeding and fasting/HFD-refeeding conditions, Klhl12 IKO mice showed no significant changes in serum lipid levels compared with controls. Although Western blot analysis revealed increased ApoB48 in the intestine, no differences in serum ApoB were detected. Similarly, IKO mice on a 12-wk WD exhibited comparable body weight gain and similar serum lipid profiles with those of control mice. Our findings demonstrate that the deletion of intestinal Klhl12 does not significantly alter systemic lipid levels or body weight under different dietary challenges, suggesting that KLHL12 is not required for lipid absorption and chylomicron metabolism.NEW & NOTEWORTHY KLHL12 has been reported to regulate the trafficking of large COPII vesicles from the ER to the Golgi, including VLDL secretion in the hepatoma cells. Lipid absorption in the intestine involves COPII-mediated trafficking of chylomicron in enterocytes. In this study, using Klhl12 intestinal knockout mice, we demonstrate that KLHL12 is not required for chylomicron secretion and lipid absorption. These findings suggest that the regulation of ApoB-containing lipoprotein secretion differs between the liver and the intestine.