| Title: | MARC1 downregulation reduces hepatocyte lipid content by increasing beta-oxidation |
| Journal: | Clinical and Molecular Hepatology |
| Published: | 23 Dec 2024 |
| Pubmed: | https://pubmed.ncbi.nlm.nih.gov/39716370/ |
| DOI: | https://doi.org/10.3350/cmh.2024.0642 |
Publication 14783
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Abstract
BACKGROUND/AIMS: Metabolic dysfunction-associated steatotic liver disease (MASLD) is a global epidemic. The disease has a strong genetic component, and a common missense variant (rs2642438) in the mitochondrial amidoxime-reducing component 1 (MARC1) gene confers protection against its onset and severity. However, there are contrasting results regarding the mechanisms that promote this protection.</p>
METHODS: We downregulated MARC1 in primary human hepatocytes (PHHs) using short interfering RNA (siRNA). We measured neutral lipid content by Oil-Red O staining and fatty acid oxidation by radiolabeled tracers. We also performed RNA-sequencing and proteomic analysis using LC-MS. Additionally, we analyzed data from 239,075 participants from the UK Biobank.</p>
RESULTS: Downregulation of MARC1 reduced neutral lipid content in PHHs homozygous for the wild type (p.A165, risk), but not for the mutant (p.T165, protective), allele. We found that this reduction was mediated by increased fatty acid utilization via β-oxidation. Consistent with these results, we found that the levels of 3-hydroxybutyrate, a by-product of β-oxidation, were higher in carriers of the rs2642438 minor allele among samples from the UK biobank, indicating higher β-oxidation in these individuals. Moreover, downregulation of the MARC1 p.A165 variant resulted in a more favorable phenotype by reducing ferroptosis and reactive oxygen species levels.</p>
CONCLUSION: MARC1 downregulation in carriers of the risk allele results in lower hepatocyte neutral lipids content due to higher β-oxidation, while upregulating beneficial pathways involved in cell survival.</p>
13 Keywords
- Alleles
- Cells, Cultured
- Down-Regulation
- Fatty Acids
- Fatty Liver
- Female
- Hepatocytes
- Humans
- Lipid Metabolism
- Male
- Middle Aged
- Oxidation-Reduction
- RNA, Small Interfering
18 Authors
- Ester Ciociola
- Tanmoy Dutta
- Kavitha Sasidharan
- Lohitesh Kovooru
- Francesca R. Noto
- Grazia Pennisi
- Salvatore Petta
- Angela Mirarchi
- Samantha Maurotti
- Bernardette Scopacasa
- Luca Tirinato
- Patrizio Candeloro
- Marcus Henricsson
- Daniel Lindén
- Oveis Jamialahmadi
- Arturo Pujia
- Rosellina M. Mancina
- Stefano Romeo
Enabling scientific discoveries that improve human health