Role of peroxisome proliferator-activated receptor β agonist on angiogenesis in hindlimb ischemic diabetic rats

Department of Physiology, Isfahan University of Medical Sciences, Isfahan, Iran.
Journal of diabetes and its complications (Impact Factor: 3.01). 03/2012; 26(2):137-40. DOI: 10.1016/j.jdiacomp.2012.02.005
Source: PubMed


Studies indicated that PPARβ agonists play a role in modulation of angiogenesis. In this study, we evaluated the effect of specific PPARβ agonist, GW0742, on angiogenesis and serum vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), and nitrite concentrations in hindlimb ischemia in normal and diabetic rats.
Hindlimb ischemic rats were divided into four groups: control, diabetic, control, and diabetic treated with GW0742 (n=7 each). Diabetes was induced by injection of streptozotocin (55mg/kg, ip). GW0742 was injected 1day after surgery (1mg/kg, sc). After 21days, blood samples were taken, and gastrocnemius muscles were harvested for immunohistochemistry.
GW0742 significantly increased serum nitrite and VEGFR-2 concentrations and VEGF-to-VEGFR-2 ratio in control and diabetic rats. Capillary density was lower in diabetic animals compared to the control, and GW0742 significantly restored the capillary density in the control and diabetic hindlimb ischemic rats.
PPARβ agonists restore skeletal muscle angiogenesis and can be considered for prevention and/or treatment of peripheral vascular complications in diabetic subjects.

8 Reads
    • "Endothelial cells are the main cells involved in the angiogenesis process. Physiological angiogenesis contributes in events such as pregnancy, embryonic development, wound healing and menstruation,[9] however, disturbances in physiologic angiogenesis can participates in various human diseases including cancer, cardiovascular diseases, diabetic complications, ocular disease and chronic inflammation[10] in the form impairment angiogenesis that leads to diabetic vasculopathy[1112] or excessive angiogenesis that can cause to diabetic retinopathy and nephropathy and inhibited angiogenesis in transplant rejection in diabetic recipients.[13] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Type 2 diabetes mellitus is a complex disease and a chronic health-care problem. Nowadays, because of alteration of lifestyle such as lack of exercise, intake of high fat diet subsequently obesity and aging population, the prevalence of diabetes mellitus is increasing quickly in around the world. The international diabetes federation estimated in 2008, that 246 million adults in worldwide suffered from diabetes mellitus and the prevalence of disease is expected to reach to 380 million by 2025. Although, mainly in management of diabetes focused on hyperglycemia, however, it is documented that abnormalities of angiogenesis may contribute in the pathogenesis of diabetes complications. Angiogenesis is the generation of new blood vessels from pre-existing ones. Normal angiogenesis depends on the intricate balance between angiogenic factors (such as VEGF, FGF(2), TGF-β, angiopoietins) and angiostatic factors (angiostatin, endostatin, thrombospondins). Vascular abnormalities in different tissues including retina and kidney can play a role in pathogenesis of micro-vascular complications of diabetes; also vascular impairment contributes in macrovascular complications e.g., diabetic neuropathy and impaired formation of coronary collaterals. Therefore, identifying of different mechanisms of the diabetic complications can give us an opportunity to prevent and/or treat the following complications and improves quality of life for patients and society. In this review, we studied the mechanisms of angiogenesis in micro-vascular and macro-vascular complications of diabetes mellitus.
    No preview · Article · Dec 2012 · International journal of preventive medicine
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Remodeling of quiescent vessels with increases in permeability, vasodilatation, and edema are hallmarks of inflammatory disorders. Factors involved in this type of remodeling represent potential therapeutic targets. We investigated whether the nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR) β/δ, a regulator of metabolism, fibrosis, and skin homeostasis, is involved in regulation of this type of remodeling. Wild-type and various Pparb/d mutant mice were used to monitor dermal acute vascular hyperpermeability (AVH) and passive systemic anaphylaxis-induced hypothermia and edema. PPARβ/δ-dependent kinase activation and remodeling of endothelial cell-cell junctions were addressed by using human endothelial cells. AVH and dilatation of dermal microvessels stimulated by vascular endothelial growth factor A, histamine, and thrombin are severely compromised in PPARβ/δ-deficient mice. Selective deletion of the Pparb/d-encoding gene in endothelial cells in vivo similarly limits dermal AVH and vasodilatation, providing evidence that endothelial PPARβ/δ is the major player in regulating acute dermal microvessel remodeling. Furthermore, endothelial PPARβ/δ regulatory functions are not restricted to the skin vasculature because its deletion in the endothelium, but not in smooth muscle cells, also leads to reduced systemic anaphylaxis, the most severe form of allergic reaction, in which an acute vascular response plays a key role. PPARβ/δ-dependent AVH activation likely involves the activation of mitogen-activated protein kinase and Akt pathways and leads to downstream destabilization of endothelial cell-cell junctions. These results unveil not only a novel function of PPARβ/δ as a direct regulator of acute vessel permeability and dilatation but also provide evidence that antagonizing PPARβ/δ represents an important strategy to consider for moderating diseases with altered endothelial integrity, such as acute inflammatory and allergic disorders. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.
    Full-text · Article · Dec 2014 · Journal of Allergy and Clinical Immunology