Exogenous nitric oxide inhibits mesangial cell adhesion to extracellular matrix components

Abstract

Interactions of mesangial cells (MCs) with components of the extracellular matrix (ECM) profoundly influence the MC phenotype, such as attachment, contraction, migration, survival and proliferation. Here, we investigated the effects of exogenous nitric oxide (NO) on the process of MC adhesion to ECM molecules. Incubation of rat MCs with the NO donor S-nitroso-N-acetylpenicillamine (SNAP) dose- and time-dependently inhibited MC adhesion and spreading on various ECM substrata, being more pronounced on collagen type I than on collagen type IV, laminin or fibronectin. In contrast, SNAP did not inhibit MC adhesion to L-polylysine-coated plates. The inhibitory effects of SNAP were reduced by hemoglobin and enhanced by superoxide dismutase. The anti-adhesive action of SNAP was mimicked not only by other NO donors but also by 8-bromo-cGMP, and significantly reversed by the soluble guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3,-alpha]quinoxalin-1-one (ODQ). Moreover, SNAP and 8-bromo-cGMP decreased the adhesion-induced phosphorylation of focal adhesion kinase (pp125FAK). In the presence of SNAP or 8-bromo-cGMP, adherent MCs exhibited disturbed organization of alpha-actin filaments and reduced numbers of focal adhesions, as shown by immunocytochemistry. In additional experiments with adherent MCs, it was found that exposure to SNAP or 8-bromo-cGMP for 12 and 24 hours induced detachment of MCs. The results indicate that exogenous NO interferes with the establishment and maintenance of MC adhesion to ECM components. This inhibitory NO effect is mediated predominantly by cGMP-signaling. Disturbance of MC attachment to ECM molecules could represent an important mechanism by which NO affects MC behavior in vitro and in vivo.

Nitric Oxide and C-Type Atrial Natriuretic Peptide Stimulate Primary Aortic Smooth Muscle Cell Migration via a cGMP-Dependent Mechanism

“…35,45 Similarly, actin stress fiber disassembly has been associated with increased migration in vascular smooth muscle cells. 36,37,46 NO was also shown to decrease cell adhesion in cultured mesangial cells, 47 and a preliminary experiment indicates the existence of a similar effect in primary aortic smooth muscle cell cultures. We therefore speculate that NO-induced cytoskeletal rearrangements may be causally related to increased cell migration in a model of primary aortic smooth muscle cells.…”

cGMP-dependent Protein Kinase Inhibits Serum-response Element-dependent Transcription by Inhibiting Rho Activation and Functions

“…In vascular SMCs, G-kinase inhibits RhoA-induced calcium sensitization of the contractile apparatus, which contributes to the vasodilatory effects of NO/cGMP (16, 19 -21). In several cell types including vascular SMCs, G-kinase activation induces cytoskeletal disorganization with the break down of stress fibers and disassembly of focal adhesion complexes (19,22,44,65,66). Activation of protein kinase A similarly inhibits agonist-induced smooth muscle contraction and induces stress fiber/focal adhesion breakdown in different cells; in addition, cAMP inhibits Rho-dependent leukocyte adhesion and induces morphological changes in neuronal and glial cells that are reciprocal to those induced by RhoA activation (21,57,60,(67)(68)(69).…”

Biglycan, a Nitric Oxide-regulated Gene, Affects Adhesion, Growth, and Survival of Mesangial Cells

“…Besides infiltrating cells, renal mesangial cells (MCs), exposed to inflammatory cytokines such as interleukin-1␤ (IL-1␤) or tumor necrosis factor-␣ (TNF␣), start to express iNOS followed by enhanced generation of NO (29). NO exerts complex regulatory actions on proliferation (30,31), adhesion (32), and death of MCs (33,34).…”