Nonselective alpha-/beta- AR antagonists can inhibit pericyte proliferation, migration, and secretion in vitro

It has been reported that the beta-adrenergic receptor blocker (propranolol) and the a-adrenergic receptor (AR) blocker (phentolamine) both can inhibit human endothelial cell (EC) angiogenesis in vitro. However, it is unknown whether this inhibition also acts on pericytes. The present study aimed to determine how pericytes react to treatment with an a-/β- AR blocker. In the study, cell proliferation assays and scratch assay were performed to assess the effect of phentolamine or propranolol on cell proliferation and migration. Western blot and ELISA were employed to determine changes in VEGF-A and Ang-1 expression levels. The results indicated that the nonselective a-/β- AR blocker inhibited the proliferation, migration, and secretion of pericytes. The use of the nonselective a-/β- AR blocker might have an impact on vascularization and vascular maturation. Our research suggests the rational use of nonselective a-/β- AR blockers to treat angiogenesis-dependent diseases.

β-Adrenergic Blocker, Carvedilol, Abolishes Ameliorating Actions of Adipose-Derived Stem Cell Sheets on Cardiac Dysfunction and Remodeling After Myocardial Infarction

BACKGROUND

Treatment of myocardial infarction (MI) includes inhibition of the sympathetic nervous system (SNS). Cell-based therapy using adipose-derived stem cells (ASCs) has emerged as a novel therapeutic approach to treat heart failure in MI. The purpose of this study was to determine whether a combination of ASC transplantation and SNS inhibition synergistically improves cardiac functions after MI.Methods and Results:ASCs were isolated from fat tissues of Lewis rats. In in vitro studies using cultured ASC cells, mRNA levels of angiogenic factors under normoxia or hypoxia, and the effects of norepinephrine and a β-blocker, carvedilol, on the mRNA levels were determined. Hypoxia increased vascular endothelial growth factor (VEGF) mRNA in ASCs. Norepinephrine further increased VEGF mRNA; this effect was unaffected by carvedilol. VEGF promoted VEGF receptor phosphorylation and tube formation of human umbilical vein endothelial cells, which were inhibited by carvedilol. In in vivo studies using a rat MI model, transplanted ASC sheets improved contractile functions of MI hearts; they also facilitated neovascularization and suppressed fibrosis after MI. These beneficial effects of ASC sheets were abolished by carvedilol. The effects of ASC sheets and carvedilol on MI heart functions were confirmed by Langendorff perfusion experiments using isolated hearts.

CONCLUSIONS

ASC sheets prevented cardiac dysfunctions and remodeling after MI in a rat model via VEGF secretion. Inhibition of VEGF effects by carvedilol abolished their beneficial effects.