Vascular endothelial growth factor-A and transforminggrowth factor-β1 expression in postmenopausal osteoporosis:a histological and immunohistochemical study

BackgroundVascular endothelial growth factor (VEGF) plays an important role in boneangiogenesis, whereas transforming growth factor-β1 (TGF-β1) modulates bonedifferentiation, matrix formation, and cytokine expression.Aim of the workThe aim of the study was to assess the immune expression of VEGF and TGF-β1 incells lining the bone trabeculae among postmenopausal women in relation to bonehistomorphometry and their association with osteoporosis.Patients and methodsA total of 30 postmenopausal women were recruited for the study. Bone mineraldensity was measured using DEXA. On the basis of the results of the DEXA scan,they were divided as follows: group I comprised 14 (46.7%) women with normalbone mineral density; group II comprised five (16.7%) women with osteopenia; andgroup III comprised 11 (36.7%) women with osteoporosis. Iliac crest bone biopsywas taken from each of them. Histomorphometrical study was carried out using H Estain to evaluate the trabecular microarchitecture in addition to immunohistochemistryfor both VEGF and TGF-β1.ResultsHistomorphometric analysis was statistically and significantly different among thethree groups. The area percentage of both TGF-β1 protein and VEGF expressionin cells lining the bone trabeculae was statistically and significantly lower in theosteoporotic group compared with the other two groups. A statistically significantnegative correlation was found between age and menopause duration and TGF-β1only. A significant positive correlation was found between trabecular bone thicknessand both VEGF (r=0.762, P=0.000) and TGF-β1 (r=0.785, P=0.000). Regressionanalysis showed only VEGF (t=2.537, P=0.018), and not TGF-β1 (t=0.326,P=0.747), to have independent association with trabecular bone thickness.ConclusionThe results of the current study support that VEGF and TGF-β1 may contribute to thepathogenesis of postmenopausal osteoporosis. Further studies on the role of bothTGF-β1 and VEGF in postmenopausal osteoporotic patients will be helpful to clarifythe etiopathogenesis and treatment of postmenopausal osteoporosis.