Tissue Proteome of 2-Hydroxyacyl-CoA Lyase Deficient Mice Reveals Peroxisome Proliferation and Activation of ω-Oxidation

Abstract

Peroxisomal fatty acid α-oxidation is an essential pathway for the degradation of β-carbon methylated fatty acids such as phytanic acid. One enzyme in this pathway is 2-hydroxyacyl CoA lyase (HACL1), which is responsible for the cleavage of 2-hydroxyphytanoyl-CoA into pristanal and formyl-CoA. Hacl1 deficient mice do not present with a severe phenotype, unlike mice deficient in other α-oxidation enzymes such as phytanoyl-CoA hydroxylase deficiency (Refsum disease) in which neuropathy and ataxia are present. Tissues from wild-type and Hacl1−/− mice fed a high phytol diet were obtained for proteomic and lipidomic analysis. There was no phenotype observed in these mice. Liver, brain, and kidney tissues underwent trypsin digestion for untargeted proteomic liquid chromatography-mass spectrometry analysis, while liver tissues also underwent fatty acid hydrolysis, extraction, and derivatisation for fatty acid gas chromatography-mass spectrometry analysis. The liver fatty acid profile demonstrated an accumulation of phytanic and 2-hydroxyphytanic acid in the Hacl1−/− liver and significant decrease in heptadecanoic acid. The liver proteome showed a significant decrease in the abundance of Hacl1 and a significant increase in the abundance of proteins involved in PPAR signalling, peroxisome proliferation, and omega oxidation, particularly Cyp4a10 and Cyp4a14. In addition, the pathway associated with arachidonic acid metabolism was affected; Cyp2c55 was upregulated and Cyp4f14 and Cyp2b9 were downregulated. The kidney proteome revealed fewer significantly upregulated peroxisomal proteins and the brain proteome was not significantly different in Hacl1−/− mice. This study demonstrates the powerful insight brought by proteomic and metabolomic profiling of Hacl1−/− mice in better understanding disease mechanism in fatty acid α-oxidation disorders.

Inflammatory signaling on cytochrome P450-mediated drug metabolism in hepatocytes

“…PPARα activators are reported to prevent acetaminophen-induced hepatotoxicity, which involves regulation of lipid metabolism and inhibition of CYP2E1 activity ( Attal et al, 2022 ). In two previous studies, 2-hydroxyacyl-CoA lyase levels significantly decreased while proteins associated with PPAR signaling, peroxisome proliferation, and omega oxidation, specifically CYP4A10 and CYP4A14, significantly increased in the liver proteome ( Mezzar et al, 2017 ; Khalil et al, 2022 ).…”

Multi-Omics Analyses Reveal the Mechanisms of Early Stage Kidney Toxicity by Diquat

“…One of the pathway for fatty acid degradation is through oxidation, in which dicarboxylic acids are formed and subsequently undergo β-oxidation from the omega end. This pathway is catalyzed by CYP450 enzymes and the peroxisomal β-oxidation pathway which are regulated by PPARα [ 21 ] The mouse genome contains four Cyp4a genes: Cyp4a10, Cyp4a12a, Cyp4a12b, and Cyp4a14—all of which are localized in chromosome 4 [ 22 ]. Murine Cyp4a10 and Cyp4a14 (homologous to human CYP4A22 and CYP4A11, respectively) are highly expressed in the liver and kidneys, and are known to convert the arachidonic acid to its metabolite 20-hydroxyeicosatetraenoic acid (20-HETE), which regulates the inflammatory response through the generation of ROS [ 15 , 22 ].…”

HCA (2-Hydroxy-Docosahexaenoic Acid) Induces Apoptosis and Endoplasmic Reticulum Stress in Pancreatic Cancer Cells

“…In this context, it would be interesting to investigate the antitumor effect of HCA in vivo when α-oxidation is fully and specifically inhibited, which could not be reached by using OT. Further studies would be needed using Hacl KO cells or Hacl KO mice [ 59 , 60 ] in which α-oxidation is completely inhibited, potentially clarifying whether the full inhibition of HCA metabolization could constitute a good approach to potentiate its antitumoral activity.…”