Study of renal tubular epithelial cells transformations in rat tubulointerstitial fibrosis / 中华肾脏病杂志

ABSTRACT

Objective To observe the phenotypic changes between renal tubular epithelial cells and mesenchymal cells in rat tubulointerstitial fibrosis(TIF) .Methods The renal tubulointerstitial fibrosis models of Wistar rats were established by gavage with excessive adenine. The morphological changes of model kidney were observed by light microscopy, electron microscopy, polarizing microscopy. The?-smooth muscle actin(a-SMA), vimentin, and keratin were examined by immunohistochemistry staining. While the proliferating cell nuclear antigen (PCNA) was also assessed. Results There were many 2, 8-dioxyadenine crystals derived from the metabolite of adenine to deposit in the renal tubules, which induced the injury. Tubular epithelial cells degeneration and regeneration, loss of renal tubules, mononuclear cells infiltration in renal interstitium and the accumulation of extracellular matrix protein were observed. Both ?-SMA and vimentin were positive in some of renal tubules. And consecutive sections of immunohistochemical staining showed that the area of distribution of a-SMA positive cells was almost the same area as that of vimentin positive cells. Polarizing microscopy results showed that there was a mass of interstitial collagen ( Ⅲ and Ⅰ) accumulation. And electron microscopy examination proved that epithelial cells invaded into the renal interstitium. Conclusion There is tubular epithelial cells-myofibroblasts transdifferentiation in the process of TIF, and which plays a key role in the accumulation of extracellular matrix.