Alterations in phenotype and gene expression of adult human aneurysmal smooth muscle cells by exogenous nitric oxide

Abstract

Alterations in phenotype and gene expression of adult human aneurysmal smooth muscle cells by exogenous nitric oxide. AbstractAbdominal aortic aneurysms (AAA) are characterized by matrix remodeling, elastin degradation, absence of nitric oxide (NO) signaling, and inflammation, influencing smooth muscle cell (SMC) phenotype and genotype. Little is known about the biomolecular release and intrinsic biomechanics of human AAA-SMCs. NO delivery could be an attractive therapeutic strategy to restore lost functionality of AAA-SMCs by inhibiting inflammation and cell stiffening. We aim to establish the differences in phenotype and genotype of adult human AAA-SMCs from healthy SMCs. Based on our previous study which showed benefits of optimal NO dosage delivered via S-Nitrosoglutathione (GSNO) to healthy aortic SMCs, we tested whether such benefits would occur in AAA-SMCs. The mRNA expression of three genes involved in matrix degradation (ACE, ADAMTS5 and ADAMTS8) was significantly downregulated in AAA-SMCs. Total protein and glycosaminoglycans synthesis were higher in AAA-SMCs than healthy-SMCs and was enhanced by GSNO and 3D cultures. Elastin gene expression, synthesis and deposition, desmosine crosslinker levels, and lysyl oxidase (LOX) functional activity were lower, while cell proliferation, iNOS, LOX and fibrillin-1 gene expressions were higher in AAA-SMCs, with differential benefits from GSNO exposure. GSNO and 3D cultures reduced MMPs -2, -9, and increased TIMP-1 release in AAA-SMC cultures. AAA-SMCs were inherently stiffer and had smoother surface than healthy SMCs, but GSNO reduced stiffness (~25%) and increased roughness of both cell types. In conclusion, exogenously-delivered NO offers an attractive strategy by providing therapeutic benefits to AAA-SMCs.We hereby submit our manuscript titled, "Improvement of altered phenotype and genotype of adult human aneurysmal smooth muscle cells by exogenous nitric oxide" to be considered for publication in the Nitric Oxide journal as an original full-length article. All authors have read and agreed with the submission of the manuscript to this journal. This manuscript hasn't been submitted or published elsewhere, either in part or in full. Novelty of this work:It is known that the pathogenesis of aortic aneurysms leads to extracellular matrix degradation in blood vessels and disruption of vascular smooth muscle cell (SMC) interactions with endothelium and medial elastic fibers. In this work, we report for the first time, on the basal amounts of numerous matrix proteins synthesized and released by aortic aneurysmal SMCs derived from LILAS (Lille Aneurysmal Study in France) patients, changes in their phenotype and genotype, the cytokines/ chemokines/ growth factors they release, and their intrinsic biophysical characteristics (cell stiffness and surface roughness). In addition, we compared such outcomes from aneurysmal cells to SMCs derived from healthy humans. Finally, we report on the benefits of delivering exogenous nitric oxide cues to restore some of these lost biophy...

Experimental aortic aneurysm severity and growth depend on topical elastase concentration and lysyl oxidase inhibition

“…found specific rare variants of the LOX gene in humans with enlarged aortic root and ascending aortic dissections 42 . Further study in the smooth muscle cells of humans indicated that in those taken from human AAAs, LOX gene expression was higher, but the LOX functional activity was significantly reduced compared to healthy controls 43 . These all suggest the importance of LOX clinically.…”

Plasma Metabolomics Analysis Identifies Abnormal Energy, Lipid, and Amino Acid Metabolism in Abdominal Aortic Aneurysms

“…Arginine deficiency can lead to the development of atherosclerosis, based on the fact that it leads to impairment of NO synthesis and consequently affects the function of vascular endothelial cells [ 28 ]. However, the formation of AAAs may be related to excessive NO produced by vascular smooth muscle cells, which promotes the degradation of elastin and the destruction of the extracellular matrix [ 29 , 30 ]. Glutamate and glutamine are precursors of l-arginine and a substrate for ATP and protein synthesis.…”

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“…In animal models, reduced ROS generation, iNOS deficiency, inhibition of VSMC loss, and NOX attenuate AAA formation (259). Besides, the expression of iNOS is higher in HAoSMCs in patients with AAA in comparison with healthy controls (72).…”