Alterations of the glomerular podocytes in puromycin aminonucleoside [PAN] EXPE rimental nephrosis in adult male albino mice an ultrastructural and immunofluorescence study

ABSTRACT

Advances in molecular genetics have led to the discovery of specialized protein molecules endowed in podocytes as responsible for proteinuria. However, the precise function and the molecular interactions among these proteins remain unclear. The present work was done to verify immunohistochemically the glomerular localization of nephrin and podocin in normal and experimental protein uric animal models, and to correlate tile findings with the ultrastructural alterations. Forty adult male albino mice were used and divided into five groups, the first group was the control and the other four groups were the experimental. Animals of the experimental groups received a single intravenous injection of puromycin aminonucleoside [PAN], and were sacrificed at 1, 2, 10 days and 3 weeks post-injection respectively. Nephrin and podocin localization was assessed by immnunofluorescence microscopy using polyclonal antibodies against nephrin and podocin, while morphological changes were determined by electron microscopy. Normal kidney sections showed a consistently linear staining pattern for both nephrin and podocin, whereas, sections from PAN-treated animals, showed a granular labelling pattern as well as marked loss of both proteins. Ultrastructurally, swelling, fusion and even complete effacement of the foot processes, and loss of the slit diaphragms were observed. The present study showed that nephrin and podocin distribution was altered in PAN-treated rats, and this occurred in parallel with foot process effacement. Nephrin and podocin labelling returned to normal with improved resolution of the effacement