Transcriptomic sequencing reveals diverse adaptive gene expression responses of human vascular smooth muscle cells to nitro-conjugated linoleic acid

Abstract

Nitro-conjugated linoleic acid (NO-CLA) is formed by metabolic and inflammatory reactions of nitric oxide and nitrite, and represents the most abundant nitro-fatty acid species in humans. These electrophilic fatty acid nitroalkene derivatives mediate pleiotropic cell signaling responses. Here, we report a systematic approach to investigate the effect of NO-CLA on human coronary artery smooth muscle cells (hCASMC), based on the RNA-Seq and bioinformatics analysis. There were extensive differentially expressed genes in NO-CLA vs. control (510) and NO-CLA vs. CLA (272) treatment groups, respectively. Notably, only minimal alterations were observed in CLA vs. control conditions, indicating that the electrophilic character of NO-CLA is requited to induce differential gene expression responses independently from native CLA. Functional enrichment analysis of differentially expressed genes reveals multiple cellular processes to be affected under NO-CLA treatment, including cell proliferation, lipid metabolism, antioxidant and inflammatory-related gene expression responses. These findings reveal that nitro-fatty acid derivatives such as NO-CLA regulate a broad array of adaptive gene expression responses by hCASMC.

The discovery of nitro-fatty acids as products of metabolic and inflammatory reactions and mediators of adaptive cell signaling

“…Of relevance to the anti-inflammatory actions of NO 2 -FA is the potent and multifaceted inhibition of NF-κB-mediated signaling, as demonstrated in diverse cell and murine models of cancer, metabolic syndrome, cardiopulmonary disease and both acute and chronic renal disease (87–90). Unbiased gene expression response studies in human vascular endothelial and smooth muscle cells affirm the broad and pleiotropic modulation of adaptive cell responses by NO 2 -FA that would be anticipated from the PTM of key transcriptional regulatory proteins (91,92). Functional enrichment analysis of differentially expressed genes reveals multiple cellular processes will be affected, including cell proliferation, lipid metabolism, antioxidant and inflammatory-related gene expression responses.…”

Redox properties and human serum albumin binding of nitro-oleic acid

“…This is demonstrated in diverse cell and murine models of cancer, and metabolic syndrome and cardiopulmonary and renal inflammatory responses [19,[67], [68], [69]]. Gene expression response studies in human vascular cells reinforce that there is extensive pleiotropic modulation of adaptive cell responses that are related to cell proliferation, lipid metabolism, antioxidant and anti-inflammatory reactions [70,71]. The present study also shows the important role that plasma proteins can play in non-covalent systemic transport of NO 2 -OA, since the large pool of plasma albumin has the capacity of binding and stabilizing extensive quantities of this and other electrophilic fatty acids.…”

A FABP4-PPARγ signaling axis regulates human monocyte responses to electrophilic fatty acid nitroalkenes

“…Among NO 2 -FA, NO 2 -CLA induced a greater magnitude of PPARγ activation, as shown by its unique upregulation of CD36 expression, a response inhibited by GW9662. This expands our knowledge of the biological actions of NO 2 -CLA in monocytes and macrophages and presumably other cells [5,17,73,74]. Because CLA behaves as a preferential FA target for nitration at physiological conditions [5], PPARγ activation by NO 2 -CLA could be biologically more relevant than that mediated by other NO 2 -FA.…”