Effects of placental-derived mesenchymal stem cells on proliferation and apoptosis mechanisms in chronic kidney disease

Stem cells have many important roles in progression of normal development and adult tissue regeneration. Adult stem cells provide regeneration of life limited stem cells thus permanence of tissues. They can response to injury and regenerate damaged tissues. Mesenchymal stem cells (MSCs) are one of the adult stem cells and they can differentiate into many cell lines and self-renewal. They can differentiate into osteocytes, adipocytes and chondrocytes. Many experiments have shown that placenta can be used as a source of mesenchymal stem cell as well stroma of umblical cord, amnion fluid and amniotic membrane. Recent studies determined the amnion membrane has most of mesenchymal stem cells that can differentiate into osteocyte and adipocyte. The feature of chronic kidney failure (CKF) is lost of kidney functions due to erosion of healty tissue and fibrosis. Following injury, the regenerative capacity of kidney is shown by the replacement of damaged kidney tubules. Recent studies showed that MSCs differentiated to tubular epitelial cells thus renal function and structures renewed. Furthermore, MSCs protect renal function in CKF. They can engraft to kidney and secrete growth factors thus they prevent renal injury. Aristolochic acid (AA) gives rise to CKF. Morphologically, AA is characterized by interstitial fibrosis that causes tubular atrophy. We constituted rat model of CKF by applying AA in this study. 6x10⁵ mesenchymal stem cells that were isolated from amnion membrane transplanted into tail vein of rats. At the end of 30 day and 60 day recovery period, expression of PCNA and Ki67 proliferation markers increased in stem cell groups according to CKF group. Furthermore, expression of PARP-1 apoptosis marker increased in CKF group according to control, stem cell groups and sham group and it was supported with TUNEL. Also p57 that is cell cycle inhibitory protein increased in CKF group when compared to control, stem cell groups and sham groups. In this study, mesenchymal stem cells isolated from human placenta exhibited significant effects on proliferation and apoptosis mechanisms in the chronic kidney failure.