Development and characterization of islet‐derived mesenchymal stem cells from clinical grade neonatal porcine cryopreserved islets

Abstract

AbstractBackgroundPorcine tissues display a great potential as donor tissues in xenotransplantation, including cell therapy. Cryopreserving clinical grade porcine tissue and using it as a source for establishing therapeutic cells should be advantageous for transportation and scheduled manufacturing of MSCs. Of note, we previously performed encapsulated porcine islet transplantation for the treatment of unstable type 1 diabetes mellitus in the clinical setting. It has been reported that co‐transplantation of islets and Mesenchymal stem cells (MSCs) enhanced efficacy. We assume that co‐transplantation of porcine islets and porcine islet‐derived MSCs could improve the efficacy of clinical islet xenotransplantation.MethodsMSCs were established from fresh and cryopreserved non‐clinical grade neonatal porcine islets and bone marrow (termed non‐clinical grade npISLET‐MSCs and npBM‐MSCs, respectively), as well as from cryopreserved clinical grade neonatal porcine islets (termed clinical grade npISLET‐MSCs). Subsequently, the cell proliferation rate and diameter, surface marker expression, adipogenesis, osteogenesis, and colony‐forming efficiency of the MSCs were assessed.ResultsCell proliferation rate and diameter did not differ between clinical grade and non‐clinical grade npISLET‐MSCs. However, non‐clinical grade npBM‐MSCs were significantly shorter and smaller than both npISLET‐MSCs (p < 0.05). MSC markers (CD29, CD44, and CD90) were strongly expressed in clinical grade npISLET‐MSCs and non‐clinical grade npISLET‐MSCs and npBM‐MSCs. The expression of MSC‐negative markers CD31, CD34, and SLA‐DR was low in all MSCs. Clinical grade npISLET‐MSCs derived from adipose and osteoid tissues were positive for Oil Red and alkaline phosphatase staining. The results of colony‐forming assay were not significantly different between clinical grade npISLET‐MSCs and non‐clinical grade npBM‐MSCs.ConclusionThe method described herein was successful in of developing clinical grade npISLET‐MSCs from cryopreserved islets. Cryopreserved clinical grade porcine islets could be an excellent stable source of MSCs for cell therapy.