In:
Arteriosclerosis, Thrombosis, and Vascular Biology, Ovid Technologies (Wolters Kluwer Health), Vol. 38, No. 10 ( 2018-10), p. 2423-2434
Abstract:
Actin cytoskeleton assembly and organization, as a result of focal adhesion (FA) formation during cell adhesion, are dependent on reactive oxygen species and the cellular redox environment. Poldip2 (polymerase δ-interacting protein 2), a novel regulator of NOX4 (NADPH oxidase 4), plays a significant role in reactive oxygen species production and cytoskeletal remodeling. Thus, we hypothesized that endogenous reactive oxygen species derived from Poldip2/NOX4 contribute to redox regulation of actin and cytoskeleton assembly during integrin-mediated cell adhesion. Approach and Results— Using vascular smooth muscle cells, we verified that hydrogen peroxide (H 2 O 2 ) levels increase during integrin-mediated cell attachment as a result of activation of NOX4. Filamentous actin (F-actin) was oxidized by sulfenylation during cell attachment, with a peak at 3 hours (0.80±0.04 versus 0.08±0.13 arbitrary units at time zero), which was enhanced by overexpression of Poldip2. Depletion of Poldip2 or NOX4 using siRNA, or scavenging of endogenous H 2 O 2 with catalase, inhibited F-actin oxidation by 78±26%, 99±1%, and 98±1%, respectively. To determine the consequence of F-actin oxidation, we examined the binding of F-actin to vinculin, a protein involved in FA complexes that regulates FA maturation. Vinculin binding during cell adhesion as well as migration capacity were inhibited after transfection with actin containing 2 oxidation-resistant point mutations (C272A and C374A). Silencing of Poldip2 or NOX4 also impaired actin–vinculin interaction, which disturbed maturation of FAs and inhibited cell migration. Conclusions— These results suggest that integrin engagement during cell attachment activates Poldip2/Nox4 to oxidize actin, which modulates FA assembly.
Type of Medium:
Online Resource
ISSN:
1079-5642
,
1524-4636
DOI:
10.1161/ATVBAHA.118.311668
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2018
detail.hit.zdb_id:
1494427-3
