Bone marrow stem cell therapy for renal regeneration after acute tubular necrosis: A dream or a reality?

Bone marrow transplantation and organ transplantation studies suggest that bone marrow cells can differentiate into a variety of non-hematological tissues, including renal cells. The results of a number of experimental animal studies also showed that cell therapy (bone marrow cells (BMCs), hematopoietic stem cells (HSCs), mesenchymal stem cells (MSCs)) might have the potential to rescue animals from organ injuries. However, when BMCs or HSCs were injected into rodents subjected to ischemic or toxin-induced acute tubular necrosis (ATN), the results with regard to whether they could rescue rodents from ATN were inconsistent. The reasons for the conflicting results of BMC or HSC therapy in ATN are unknown, but may be due to the different types of cells injected, number of cells injected, route of injection, or injury model of acute renal failure. It is known that MSCs can contribute to renal tubular regeneration after ATN, although the exact mechanism, either transdifferentiation or effects of paracrine/cytokines, is uncertain. In the future, the most pertinent issue is to determine how MSCs protect the renal tubule from injury, and then to imitate this protective or reparative effect pharmacologically.