Comparison of mechanisms of angiostasis caused by the anti-inflammatory steroid 5α-tetrahydrocorticosterone versus conventional glucocorticoids

• Published in: European journal of pharmacology 2022-08, Vol.929, p.175111-175111, Article 175111
• Main Authors: Abernethie, Amber J., Gastaldello, Annalisa, Maltese, Giorgia, Morgan, Ruth A., McInnes, Kerry J., Small, Gary R., Walker, Brian R., Livingstone, Dawn EW, Hadoke, Patrick WF, Andrew, Ruth
• Format: Article
• Language: English
• Subjects: 5α-tetrahydrocorticosterone; Angiogenesis; Animals; Anti-Inflammatory Agents - pharmacology; Anti-Inflammatory Agents - therapeutic use; Blood vessel; Corticosterone - analogs & derivatives; Corticosterone - pharmacology; Dexamethasone - pharmacology; Glucocorticoids; Glucocorticoids - pharmacology; Hydrocortisone - pharmacology; Inflammation; Male; Mice; Mice, Inbred C57BL; Mifepristone - pharmacology; Neovascularization, Pathologic; Receptors, Glucocorticoid - metabolism
• ISSN: 0014-2999; 1879-0712
• DOI: 10.1016/j.ejphar.2022.175111

5α-Tetrahydrocorticosterone (5αTHB) is an effective topical anti-inflammatory agent in mouse, with less propensity to cause skin thinning and impede new blood vessel growth compared with corticosterone. Its anti-inflammatory effects were not prevented by RU38486, a glucocorticoid receptor antagonist, suggesting alternative mechanisms. The hypothesis that 5αTHB directly inhibits angiogenesis to a lesser extent than hydrocortisone was tested, focussing on glucocorticoid receptor mediated actions. New vessel growth from aortae from C57BL/6 male mice was monitored in culture, in the presence of 5αTHB, hydrocortisone (mixed glucocorticoid/mineralocorticoid receptor agonist) or the selective glucocorticoid receptor agonist dexamethasone. Transcript profiles were studied, as was the role of the glucocorticoid receptor, using the antagonist, RU38486. Ex vivo, 5αTHB suppressed vessel growth from aortic rings, but was less potent than hydrocortisone (EC50 2512 nM 5αTHB, versus 762 nM hydrocortisone). In contrast to conventional glucocorticoids, 5αTHB did not alter expression of genes related to extracellular matrix integrity or inflammatory signalling, but caused a small increase in Per1 transcript, and decreased transcript abundance of Pecam1 genes. RU38486 did not antagonise the residual effects of 5αTHB to suppress vessel growth or regulate gene expression, but modified effects of dexamethasone. 5αTHB did not alter expression of glucocorticoid-regulated genes Fkbp51 and Hsd11b1, unlike hydrocortisone and dexamethasone. In conclusion, compared with hydrocortisone, 5αTHB exhibits limited suppression of angiogenesis, at least directly in blood vessels and probably independent of the glucocorticoid receptor. Discriminating the mechanisms employed by 5αTHB may provide the basis for the development of novel safer anti-inflammatory drugs for topical use. •5α-Tetrahydrocorticosterone has anti-inflammatory properties but is less angiostatic than hydrocortisone.•5α-Tetrahydrocorticosterone suppressed angiogenesis from mouse aortic rings ex vivo to a limited degree.•5α-Tetrahydrocorticosterone decreased Pecam1 gene transcript associated with vascular remodelling.•Angiostatic effects of 5α-tetrahydrocorticosterone were not blocked by glucocorticoid receptor antagonism.