AUTHOR=Okui Takehito , Kuraoka Shiori , Iwashita Masaya , Itagawa Rei , Kasai Taku , Aikawa Masanori , Singh Sasha A. , Aikawa Elena 

TITLE=Carnitine O-octanoyltransferase (CROT) deficiency in mice leads to an increase of omega-3 fatty acids

JOURNAL=Frontiers in Molecular Biosciences

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/molecular-biosciences/articles/10.3389/fmolb.2024.1374316

DOI=10.3389/fmolb.2024.1374316

ISSN=2296-889X

ABSTRACT=<p><bold>Introduction:</bold> Carnitine O-octanoyltransferase (CROT) is a well-established peroxisomal enzyme involved in liver fatty acid oxidation, but less is known about its recently discovered role in promoting vascular calcification, and whether CROT-dependent liver metabolism contributes to the latter. To date, CROT function in the context of calcification potential has been conducted in the dyslipidemic low-density lipoprotein receptor-deficient (<italic>Ldlr−/−</italic>) mice.</p><p><bold>Objectives:</bold> To differentiate peroxisome and CROT-dependent lipid biology from that of lipoprotein-mediated lipid biology, we therefore conducted a metabolomic analysis of the liver and plasma of normolipidemic CROT-deficient (<italic>Crot−/−</italic>) mice.</p><p><bold>Methods:</bold> We performed LC-MS-based metabolomics on liver and plasma derived from <italic>Crot−/−</italic> and <italic>Crot</italic> +/− mice and sibling <italic>Crot+/+</italic> mice, using a dual-phase metabolite extraction protocol, and multiple LC-MS acquisition strategies.</p><p><bold>Results:</bold> We identified between 79 to 453 annotated metabolites from annotated metabolites from liver samples, and 117 to 424 annotated metabolites from plasma samples. Through differential abundance analysis, we determined that omega-3 fatty acids such as EPA, DPA, and DHA were higher in the liver of <italic>Crot−/−</italic> and <italic>Crot</italic> +/− mice than <italic>Crot+/+</italic> mice. EPA were higher in plasma of <italic>Crot−/−</italic> mice than <italic>Crot+/+</italic> mice. We also determined that the anti-inflammatory dicarboxylic acids, tetradecanedioic acid and azelaic acid, were higher in the plasma of CROT-deficient mice.</p><p><bold>Conclusion:</bold> Our study associated genetic CROT deletion with increased levels of anti-inflammatory molecules in mouse liver and plasma. These results suggest a potential mechanism for anti-calcification effects of CROT suppression and the potential use of omega-3 fatty acids as biomarkers for future CROT inhibition therapies.</p>