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Datta R, Gholampour MA, Yang CD, Volk R, Lin S, Podolsky MJ, Arnold T, Rieder F, Zaro BW, Verzi M, Lehner R, Abumrad N, Lizama CO, Atabai K. MFGE8 links absorption of dietary fatty acids with catabolism of enterocyte lipid stores through HNF4γ-dependent transcription of CES enzymes. Cell Rep 2023; 42:112249. [PMID: 36924494 PMCID: PMC10138282 DOI: 10.1016/j.celrep.2023.112249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/21/2022] [Accepted: 02/25/2023] [Indexed: 03/17/2023] Open
Abstract
Enterocytes modulate the extent of postprandial lipemia by storing dietary fats in cytoplasmic lipid droplets (cLDs). We have previously shown that the integrin ligand MFGE8 links absorption of dietary fats with activation of triglyceride (TG) hydrolases that catabolize cLDs for chylomicron production. Here, we identify CES1D as the key hydrolase downstream of the MFGE8-αvβ5 integrin pathway that regulates catabolism of diet-derived cLDs. Mfge8 knockout (KO) enterocytes have reduced CES1D transcript and protein levels and reduced protein levels of the transcription factor HNF4γ. Both Ces1d and Hnf4γ KO mice have decreased enterocyte TG hydrolase activity coupled with retention of TG in cLDs. Mechanistically, MFGE8-dependent fatty acid uptake through CD36 stabilizes HNF4γ protein level; HNF4γ then increases Ces1d transcription. Our work identifies a regulatory network that regulates the severity of postprandial lipemia by linking dietary fat absorption with protein stabilization of a transcription factor that increases expression of hydrolases responsible for catabolizing diet-derived cLDs.
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Affiliation(s)
- Ritwik Datta
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Mohammad A Gholampour
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Christopher D Yang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Regan Volk
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Sinan Lin
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases and Surgery Institute, Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Michael J Podolsky
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Thomas Arnold
- Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Florian Rieder
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases and Surgery Institute, Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Balyn W Zaro
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | | | - Richard Lehner
- Department of Pediatrics, University of Alberta, Edmonton, AB T6G 1C9, Canada
| | - Nada Abumrad
- Washington University School of Medicine in St. Louis, St. Louis, MO 63110, USA
| | - Carlos O Lizama
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kamran Atabai
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA.
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Sasaki S, Urabe M, Maeda T, Suzuki J, Irie R, Suzuki M, Tomaru Y, Sakaguchi M, Gonzalez FJ, Inoue Y. Induction of Hepatic Metabolic Functions by a Novel Variant of Hepatocyte Nuclear Factor 4γ. Mol Cell Biol 2018; 38:e00213-18. [PMID: 30224520 DOI: 10.1128/MCB.00213-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 09/04/2018] [Indexed: 12/13/2022] Open
Abstract
Hepatocyte nuclear factor 4α (HNF4α) is a critical factor for hepatocyte differentiation. HNF4α expression is decreased in hepatocellular carcinoma (HCC), which suggests a role in repression of hepatocyte dedifferentiation. In the present study, hepatic expression of HNF4γ was increased in liver-specific Hnf4a-null mice. The HNF4γ whose expression was increased contained two variants, a known short variant, designated HNF4γ1, and a novel long variant, designated HNF4γ2. HNF4G2 mRNA was highly expressed in small intestine, and the transactivation potential of HNF4γ2 was the strongest among these variants, but the potential of HNF4γ1 was the lowest. Cotransfection experiments revealed that HNF4γ1 repressed HNF4α- and HNF4γ2-dependent transactivation, while HNF4γ2 promoted HNF4α-dependent transactivation. HNF4γ1 and HNF4γ2 were able to bind to the HNF4α binding sites with an affinity similar to that of HNF4α. Furthermore, HNF4γ2, but not HNF4γ1, robustly induced the expression of typical HNF4α target genes to a greater degree than HNF4α. Additionally, HNF4γ2 suppressed proliferation of hepatoma cells as well as HNF4α and HNF4γ1 did, and HNF4γ2 induced critical hepatic functions, such as glucose and urea production, and cytochrome P450 1A2 activity more strongly than HNF4α and HNF4γ1 did. These results indicate that HNF4γ2 has potential for redifferentiation of HCC and thus may be explored as a target for HCC therapy.
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