![]() |
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
ENDOCRINE AND DIABETES
/Activin Receptor-Like Kinase-4/5/7/Smad2 Signaling PathwayDepartment of Pharmacology, School of Medicine, Universidad Complutense, Madrid, Spain
Alterations in vascular wall remodeling are a typical complication in type 2 diabetes mellitus due to an imbalance between cell proliferation and apoptosis. In this context, we have previously shown that vascular smooth muscle cells (VSMC) from diabetic patients were resistant to induced apoptosis. Thiazolidinediones, such as pioglitazone, seem to exert direct antiatherosclerotic effects on type 2 diabetes. Here, we aimed to study whether pioglitazone was able to induce apoptosis in VSMC from diabetic patients (DP) and, if so, whether the transforming growth factor (TGF)-
1/Smad-2 pathway was involved. We isolated human internal mammary artery VSMC from patients who had undergone coronary-artery bypass graft. Pioglitazone (100 µM) induced apoptosis in human VSMC from diabetic and nondiabetic patients (NDP), analyzed by DNA fragmentation and by degradation of Bcl-2, in high-glucose-containing medium (15 and 25 mM). This apoptotic effect was inhibited by the activin receptor-like kinase-4/5/7/Smad2 inhibitor 4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide (SB-431542), denoting that the TGF-
1/Smad-2 pathway was involved. Pioglitazone rapidly increased the extracellular TGF-
1 levels and concomitantly induced phosphorylation of Smad2 in VSMC from DP and NDP. Thus, we demonstrated that pioglitazone induced apoptosis in human VSMC from DP, which are strongly resistant to the induced apoptosis. This effect of pioglitazone might contribute in the treatment of alterations of vascular remodeling in type 2 diabetes mellitus.
Address correspondence to: Dr. Teresa Tejerina, Department of Pharmacology, School of Medicine, Universidad Complutense, 28040 Madrid, Spain. E-mail: teje{at}med.ucm.es
This article has been cited by other articles:
![]() |
K. B. Atkins, B. Irey, N. Xiang, and F. C. Brosius 3rd. A rapid, PPAR-{gamma}-dependent effect of pioglitazone on the phosphorylation of MYPT Am J Physiol Cell Physiol, May 1, 2009; 296(5): C1151 - C1161. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Z. Duan, M. G. Usher, and R. M. Mortensen Peroxisome Proliferator-Activated Receptor-{gamma}-Mediated Effects in the Vasculature Circ. Res., February 15, 2008; 102(3): 283 - 294. [Abstract] [Full Text] [PDF] |
||||