title: The contribution of bone marrow-derived cells to the development of renal interstitial fibrosis.
abstract: Recent evidence suggests that bone marrow (BM)-derived cells may integrate into the kidney, giving rise to functional renal cell types, including endothelial and epithelial cells and myofibroblasts. BM-derived cells can contribute to repair of the renal peritubular capillary (PTC) network following acute ischemic injury. However, the cell fate and regulation of BM-derived cells during the progression of chronic renal disease remains unclear. Using chimeric mice transplanted with enhanced green fluorescent protein (EGFP)-expressing BM, we demonstrate that the number of BM-derived myofibroblasts coincided with the development of fibrosis in a mouse adriamycin (ADR)-induced nephrosis model of chronic, progressive renal fibrosis. Four weeks after ADR injection, increased numbers of BM-derived myofibroblasts were observed in the interstitium of ADR-injected mice. Six weeks after ADR injection, more than 30% of renal alpha-smooth muscle actin (+) (alpha-SMA+) interstitial myofibroblasts were derived from the BM. In addition, BM-derived cells were observed to express the endothelial cell marker CD31 and the myofibroblast marker alpha-SMA. Blockade of p38 mitogen-activated protein kinase (MAPK) and transforming growth factor (TGF)-beta1/Smad2 signaling was found to protect BM-derived PTC endothelial cells and inhibit the number of BM-derived von Willebrand factor (vWF)(+)/EGFP(+)/alpha-SMA(+) cells, EGFP(+)/alpha-SMA(+) cells, and total alpha-SMA(+) cells in ADR-injected mice. Inhibition of the p38 MAPK and TGF-beta1/Smad signaling pathways enhanced PTC repair by decreasing endothelial-myofibroblast transformation, leading to structural and functional renal recovery and the attenuation of renal interstitial fibrosis. Investigation of the signaling pathways that regulate the differentiation and survival of BM-derived cells in a progressive disease setting is vital for the successful development of cell-based therapies for renal repair.
authors.affiliation: Monash Immunology and Stem Cell Laboratories (MISCL), Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Li
authors.forename: James A
authors.initials: JA
authors.lastname: Deane
authors.forename: Naomi V
authors.initials: NV
authors.lastname: Campanale
authors.forename: John F
authors.initials: JF
authors.lastname: Bertram
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Ricardo
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000502:physiology*; D016026:Bone Marrow Transplantation; D002196:Capillaries / Q000503:physiopathology; D017690:Cell Transplantation / Q000379:methods*; D003404:Creatinine / Q000378:metabolism; D005819:Genetic Markers; D007684:Kidney Tubules / Q000098:blood supply; D051379:Mice; D009395:Nephritis, Interstitial / Q000503:physiopathology*; D011507:Proteinuria; D019459:Urothelium / Q000473:pathology
chemical_list: D005819:Genetic Markers; D003404:Creatinine