Analysis of PDGF-AB and -BB in serum of intact and ovariectomized (OVX) pigs

Abstract only availablePrevious studies in our group demonstrated that terminal microvascular networks in dura mater of ovariectomized (OVX) pigs undergo significant remodeling characterized by a decrease in microvessel density, capillary rarefaction, and increase in blood vessel permeability. It was postulated that post OVX vascular remodeling is estrogen-dependent and could involve changes in expression levels of relevant growth factors and receptors on both systemic and local levels. Comparison of 41 relevant growth factors and receptors in serum of intact female and OVX animals using antibody array revealed most robust changes in the expression levels of platelet-derived growth factors (PDGF) -AB and -BB, both of which are potent regulators of growth and survival in a vascular tissue. To corroborate the data from the antibody array, we conducted SDS-Page and Western blot analysis using monoclonal antibody directed against B chain of PDGF, which recognizes both PDGF-AB and PDGF-BB. The Western blot analysis revealed several species of PDGF-AB and BB possibly existing in porcine serum, notably p24, p36 and p54, which are consistent with differing stages of posttranslational processing and maturation of PDGF. Densitometry analysis confirmed antibody array results showing significant decrease in PDGF-AB and PDGF-BB expression levels in post OVX animals compared to intact female swine. Our ongoing experiments aim at isolating and verifying specific bands, and analysis of the expression levels and autophosphorylation of PDGF receptors alpha and beta in different vascular compartments.Molecular Imaging Progra

Systemic and local changes in PDGF system associated with post ovariectomy microvascular remodeling in pigs [abstract]

Abstract only availablePrevious studies in our group demonstrated that terminal microvascular networks in dura mater of ovariectomized (OVX) pigs undergo significant remodeling characterized by a decrease in microvessel density, capillary rarefaction, and increase in blood vessel permeability. It was postulated that post OVX vascular remodeling is estrogen-dependent and could involve changes in the expression of relevant growth factors and receptors on both systemic and local levels. Systemically, comparison of growth factors and receptors in serum of intact female (IF) and OVX pigs using antibody array revealed most robust changes in expression levels of platelet-derived growth factors (PDGF) -AB and -BB, both of which are potent regulators of growth and survival in vascular tissue. These results were corroborated by Western blot analysis using monoclonal antibody directed against the B chain of PDGF, which recognizes both PDGF-AB and -BB. Densitometry analysis confirmed antibody array results showing a significant decrease in PDGF-AB and -BB expression levels in post OVX animals compared to IF swine. Lower levels of circulating PDGF could translate into a weakened response of systemic repair mechanisms during vascular damage in OVX animals. On a tissue level, however, two months post OVX there was a significant increase in local PDGF expression in OVX animals compared to IF swine accompanied by a corresponding increase in phosphorylation of PDGF receptor alpha. Our current hypothesis is that hypoxic stromal responses, triggered by initial microvessel loss in OVX animals, activate PDGF/VEGF system in an attempt to restore microvasculature via angiogenic processes. Ongoing studies are aimed at identifying other factors and pathways involved in the regulation of post OVX vascular remodeling.Life Sciences Undergraduate Research Opportunity Progra