Long-term Dexamethasone Treatment Increases Cardiac Galectin-3 Levels

Purpose: Glucocorticoids, which are widely prescribed around the world, cause cardiac remodeling in long-term treatment by triggering insulin resistance and increasing blood pressure. However, its role in cardiac remodeling remains unclear. Galectin-3 (gal-3) is a member of a beta-galactoside-binding animal lectins, upregulated as a result of insulin resistance and in the pressure-overloaded myocardium and regulate cardiac remodeling. We hypothesized that gal-3 may be upregulated in the myocardium with prolonged use of glucocorticoids and associated with cardiac hypertrophy.

Methods: To examine the involvement of glucocorticoids in gal-3 levels in rat myocardium, sixteen female Wistar Albino rats were assigned to control (C; n = 8) and dexamethasone (Dex; n = 8) groups. Daily dexamethasone was injected subcutaneously for 28 days at a dose of 1 mg.kg^-1. Control animals were injected with the same volume of saline. The body weight and heart weights were determined. Gal-3 levels in myocardium were determined by Western blot.

Results: Our data shows that dexamethasone administration resulted in significant increase in heart weight (p < 0.05) and HW/BW ratios (p < 0.001) and 28 days of dexamethasone administration with the dose of 1 mg.kg^-1 caused a twofold increase in the gal-3 expression in the left ventricle (p < 0.001).

Conclusion: The finding of the current study is the first to show that dexamethasone causes an increase in gal-3 levels in myocardium. Our study provides an important step in the development of possible therapeutics by determining that dexamethasone causes an increase in gal-3 levels in the myocardium and raises awareness about the follow-up of patients receiving long-term glucocorticoid therapy.