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Abstract: TH-OR078

Cell-Based Therapy and Podocyte Cell Fusion Rescue Type IV Collagen Composition in Alport Syndrome

Session Information

Category: Glomerular Diseases

  • 1201 Glomerular Diseases: Fibrosis and Extracellular Matrix


  • Lebleu, Valerie, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States
  • Alge, Joseph, Baylor College of Medicine, Houston, Texas, United States
  • Lovisa, Sara, MD Anderson Cancer Center, Houston, Texas, United States
  • Kim, Jiha, North Dakota State University, Fargo, North Dakota, United States
  • Chen, Yang, UT-MD Anderson Cancer Center, Houston, Texas, United States
  • Kanasaki, Keizo, Kanazawa Medical University, Kahoku, ISHIKAWA, Japan
  • Teng, Yingqi, Beijing Reciproca Pharmaceuticals Co. Ltd., Beijing, China
  • Gerami-Naini, Behzad, Tufts University, Boston, Massachusetts, United States
  • Sugimoto, Hikaru, MD Anderson Cancer Center, Houston, Texas, United States
  • Kato, Noritoshi, Nagoya University, Nagoya, Japan
  • Revuelta, Ignacio, Hospital Clinic. Barcelona, Barcelona, Spain
  • Miller, Caroline A., Indiana University, Indianapolis, Indiana, United States
  • Grau, Nicole, Heidelberg University Hospital, Heidelberg, Germany
  • Sleeman, Jonathan, Heidelberg University, Mannheim, Germany
  • Rafii, Shahin, Cornell, New York, New York, United States
  • Kalluri, Raghu, University of Texas MD Anderson Cancer Center, Houston, Texas, United States

Loss of function mutations in the genes encoding either of the three chains of type IV collagen forming the a3/a4/a5 protomer (COL4A3,COL4A4, and/or COL4A5genes) in Alport syndrome (AS) compromise the glomerular basement membrane (GBM) integrity and filtration function. Potential cure relies on restoring the missing chain(s) of type IV collagen; and cell-based therapies successfully delayed renal failure in mouse models of AS (Col4a3KO).


To guide the development of cell-based therapies for AS, novel genetically engineered mouse models (GEMMs) were generated and used to define which glomerular cell(s) presents with rate-limiting function in GBM type IV collagen synthesis.


In the new GEMMs, conditional deletion of Col4a3gene (Col4a3cKO), following its breeding with a constitutively expressed Cre-recombinase transgene (CMV-Cre), proved functional and phenocopied the renal disease observed in Col4a3KO mice. Using endothelial cells (Cdh5-Cre) and podocytes (Podocin-Cre) transgenics, we find that podocytes, in contrast with endothelial cells, are requisite for functional type IV collagen GBM composition in AS. Exogenously administered cells (bone marrow derived-, embryonic, and induced-pluripotent stem cells (iPSC)) rescue the renal phenotype in AS mice by restoring a functional GBM a3/a4/a5 type IV collagen composition. Using lineage-tracing genetic strategies, we uncovered that cell-based therapies ensues from the formation of a heterokaryon with recipient podocytes and rescues GBM type IV collagen composition in AS mice.


Such fusion-dependent tissue regeneration was associated with TGFb1-dependent genetic reprogramming of the injured kidney glomerular cells and required de novo synthesis of the missing type IV collagen by the fused stem cells. These experiments highlight cell fusion as a mechanistic driver of stem cell-induced tissue regeneration.