Inhibition of proliferation, migration and proteolysis contribute to corticosterone-mediated inhibition of angiogenesis

• Published in: PloS one 2012-10, Vol.7 (10), p.e46625
• Main Authors: Shikatani, Eric A, Trifonova, Anastassia, Mandel, Erin R, Liu, Sammy T K, Roudier, Emilie, Krylova, Anna, Szigiato, Andrei, Beaudry, Jacqueline, Riddell, Michael C, Haas, Tara L
• Format: Article
• Language: English
• Subjects: Angiogenesis; Animals; Biology; Biotinylation; Cell adhesion & migration; Cell growth; Cell Movement - drug effects; Cell proliferation; Cell Proliferation - drug effects; Cells, Cultured; Comparative analysis; Corticosterone; Corticosterone - pharmacology; Endothelial cells; Endothelium; FOXO1 protein; Gelatinase A; Glucocorticoids; Humans; Inhibition; Kinases; Kinesiology; Matrix Metalloproteinase 2 - metabolism; Medical research; Medicine; Microvasculature; Morphology; Motility; Muscles; Musculoskeletal system; Neovascularization, Pathologic - chemically induced; Pharmacology; Proteins; Proteolysis; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RhoA protein; Rodents; Science; Skeletal muscle; Spheroids; Steroid hormones; Steroids; Steroids (Organic compounds); Tibialis anterior muscle; Tissue Inhibitor of Metalloproteinase-2 - metabolism; Transcription; Vascular endothelial growth factor
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0046625

The angiostatic nature of pharmacological doses of glucocorticoid steroids is well known. However, the consequences of pathophysiological elevation of endogenous glucocorticoids are not well established. In the current study, we hypothesized that the angiostatic effect of corticosterone, an endogenous glucocorticoid in rodents, occurs through multi-faceted alterations in skeletal muscle microvascular endothelial cell proliferation, migration, and proteolysis. Chronic corticosterone treatment significantly reduced the capillary to fiber ratio in the tibialis anterior muscle compared to that of placebo-treated rats. Corticosterone inhibited endothelial cell sprouting from capillary segments ex vivo. Similarly, 3-dimensional endothelial cell spheroids treated with corticosterone for 48 hours showed evidence of sprout regression and reduced sprout length. Endothelial cell proliferation was reduced in corticosterone treated cells, coinciding with elevated FoxO1 and reduced VEGF production. Corticosterone treated endothelial cells exhibited reduced migration, which correlated with a reduction in RhoA activity. Furthermore, corticosterone treated endothelial cells in both 3-dimensional and monolayer cultures had decreased MMP-2 production and activation resulting in decreased proteolysis by endothelial cells, limiting their angiogenic potential. Promoter assays revealed that corticosterone treatment transcriptionally repressed MMP-2, which may map to a predicted GRE between -1510 and -1386 bp of the MMP-2 promoter. Additionally, Sp1, a known transcriptional activator of MMP-2 was decreased following corticosterone treatment. This study provides new insights into the mechanisms by which pathophysiological levels of endogenous glucocorticoids may exert angiostatic effects.