Bioactive lipids are altered in the heart, kidney, and serum of male and female F344 rats sub-chronically exposed to dietary 2-MCPD

An integrated multi-omics analysis of the effects of the food processing-induced contaminant 2-monochloropropane-1,3-diol (2-MCPD) in rat heart

Many foods including edible oils contain 2-monochloropropane-1,3-diol (2-MCPD), a processing-induced chemical contaminant. Cardiotoxic effects have been shown to result from oral 2-MCPD exposure in rodents, but the underlying mechanisms of action remain poorly understood. We undertook a comprehensive multi-omics approach to assess changes at the transcriptomic, proteomic, and oxylipin levels in heart tissues from male F344 rats that were exposed to 0 or 40 mg/kg BW/day of 2-MCPD in the diet for 90 days, in a regulatory compliant rodent bioassay. Heart tissues were collected for RNA sequencing, quantitative PCR analysis, proteomic analysis via two-dimensional gel electrophoresis and mass spectrometry, and targeted lipidomic profiling by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Transcriptomic and proteomic data analyses revealed upregulation of immune/inflammatory response processes and downregulation of energy metabolism and cardiac structure and functions. Among differentially expressed gene-protein pairs, coronin-1A, a key leukocyte-regulating protein, emerged as markedly up-regulated. Oxylipin profiling highlighted a selective suppression of docosahexaenoic acid-derived metabolites, suggesting a disruption in cardioprotective lipid pathways. These findings suggest that 2-MCPD disrupts homeostasis through inflammatory activation and suppression of metabolic and cardiac function. This research provides insights into 2-MCPD's cardiotoxicity, emphasizing the need for further studies to support hazard characterization.

Cardiac oxylipin perturbances in response to 2-monochloropropane-1,3-diol exposure are ameliorated by dietary adequacy of the essential n-3 fatty acid, α-linolenic acid

2-Monochloropropane-1,3-diol (2-MCPD) is a food contaminant with demonstrated cardiotoxicity in rats. This adverse effect was previously associated with lower anti-inflammatory docosahexaenoic acid (DHA)-derived cardiac oxylipins in F344 rats. This previous study utilized corn oil as the dietary lipid; we therefore investigated whether deficient (0.07 g/100 g diet) or adequate (0.5 g/100 g diet) dietary α-linolenic acid (ALA), the essential n-3 polyunsaturated fatty acid (PUFA), alters the oxylipin response in heart, liver, kidney, and serum of Sprague-Dawley rats exposed to 50 mg 2-MCPD/kg BW/day. ALA increased n-3 oxylipins in all tissues, reflecting greater n-3 PUFA substrate availability. In the heart, 2-MCPD increased cyclooxygenase-derived arachidonic acid oxylipins, conducive to inflammation. Adequate dietary ALA revealed 2-MCPD-induced reductions of anti-inflammatory cardiac DHA-derived oxylipins; these were not apparent in the ALA-deficient diet as these n-3 PUFA oxylipins were already reduced. Conversely, 2-MCPD increased cardiac 13-hydroxy-octadecatrienoic acid-γ (13-HOTrE-γ) levels with deficient, but not adequate, ALA diets. Multi-tissue analysis identified 13-HOTrE-γ as a marker of 2-MCPD exposure. Our study contributes to the weight-of-evidence of 2-MCPD toxicity, confirms the functional and indicative roles of oxylipins in the heart, and demonstrates that live bioassays determining chemical health hazards should use adequate n-3 PUFA diets.