Related Experiment Video
Updated: Jun 18, 2025
Quantitative Determination of De Novo Fatty Acid Synthesis in Brown Adipose Tissue Using Deuterium Oxide
Published on: May 12, 2023
ABCA1 deficiency causes tissue-specific dysregulation of the SREBP2 pathway in mice
Yoshio Yamauchi1, Sumiko Abe-Dohmae2, Noriyuki Iwamoto3
1Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan; Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya 466-8550, Japan.
Insights
ATP-binding cassette transporter A1 (ABCA1) deficiency causes Tangier disease and HDL loss. This study reveals ABCA1 deficiency dysregulates cholesterol metabolism via SREBP2 in a nutritional manner, potentially explaining disease pathology.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- ATP-binding cassette transporter A1 (ABCA1) is crucial for high-density lipoprotein (HDL) biogenesis.
- Mutations in ABCA1 lead to Tangier disease (TD), characterized by severe HDL deficiency and cholesterol accumulation.
- The mechanism behind cholesterol deposition in TD and its link to atherosclerosis is not fully understood.
Purpose of the Study:
- To investigate the role of ABCA1 deficiency in the dysregulation of the sterol regulatory element-binding protein 2 (SREBP2) pathway.
- To determine if ABCA1 deficiency impacts SREBP2 activity in a tissue-specific and nutrition-dependent manner in vivo.
- To elucidate the potential contribution of SREBP2 pathway dysregulation to the pathophysiology of Tangier disease.
Main Methods:
- Utilized Abca1 knockout (KO) mouse models.
- Assessed tissue-specific SREBP2 pathway activity.
- Examined the influence of nutritional status on SREBP2 regulation in Abca1 KO mice.
Main Results:
- ABCA1 deficiency results in tissue-specific dysregulation of SREBP2 activity in mice.
- This dysregulation is dependent on the nutritional status of the animals.
- Previously observed in vitro hyperactivation of SREBP2 by ABCA1 deficiency is confirmed in vivo.
Conclusions:
- ABCA1 deficiency leads to a complex, tissue-specific, and nutrition-dependent alteration of cholesterol homeostasis mediated by SREBP2.
- This dysregulation may represent a key mechanism contributing to the characteristic features of Tangier disease, including cholesterol deposition and premature atherosclerosis.
- Further research into this pathway could reveal therapeutic targets for Tangier disease and related metabolic disorders.
Abstract:
ABCA1 plays an essential role in the formation of high-density lipoprotein (HDL), and its mutations cause Tangier disease (TD), a familial HDL deficiency. In addition to the disappearance of HDL, TD patients exhibit cholesterol deposition in peripheral tissues through a mechanism poorly understood, which may contribute to the development of premature atherosclerosis. We and others previously showed that ABCA1 deficiency causes hyperactivation of the SREBP2 pathway in vitro. Here, we show using Abca1 knockout mice that ABCA1 deficiency leads to tissue-specific dysregulation of SREBP2 activity in a nutritional status-dependent manner, which may underlie the pathophysiology of TD.
