Multipotent mesenchymal stromal cells derived from porcine exocrine pancreas improve insulin secretion from juvenile porcine islet cell clusters

Abstract

Neonatal and juvenile porcine islet cell clusters (ICC) present an unlimited source for islet xenotransplantation to treat type 1 diabetes patients. We isolated ICC from pancreata of 14 days old juvenile piglets and characterized their maturation by immunofluorescence and insulin secretion assays. Multipotent mesenchymal stromal cells derived from exocrine tissue of same pancreata (pMSC) were characterized for their differentiation potential and ability to sustain ICC insulin secretion in vitro and in vivo. Isolation of ICC resulted in 142 ± 50 × 103 IEQ per pancreas. Immunofluorescence staining revealed increasing presence of insulin‐positive beta cells between day 9 and 21 in culture and insulin content per 500IEC of ICC increased progressively over time from 1178.4 ± 450 µg/L to 4479.7 ± 1954.2 µg/L from day 7 to 14, P < .001. Highest glucose‐induced insulin secretion by ICC was obtained at day 7 of culture and reached a fold increase of 2.9 ± 0.4 compared to basal. Expansion of adherent cells from the pig exocrine tissue resulted in a homogenous CD90+, CD34−, and CD45− fibroblast‐like cell population and differentiation into adipocytes and chondrocytes demonstrated their multipotency. Insulin release from ICC was increased in the presence of pMSC and dependent on cell‐cell contact (glucose‐induced fold increase: ICC alone: 1.6 ± 0.2; ICC + pMSC + contact: 3.2 ± 0.5, P = .0057; ICC + pMSC no‐contact: 1.9 ± 0.3; theophylline stimulation: alone: 5.4 ± 0.7; pMSC + contact: 8.4 ± 0.9, P = .013; pMSC no‐contact: 5.2 ± 0.7). After transplantation of encapsulated ICC using Ca2+‐alginate (alg) microcapsules into streptozotocin‐induced diabetic and immunocompetent mice, transient normalization of glycemia was obtained up to day 7 post‐transplant, whereas ICC co‐encapsulated with pMSC did not improve glycemia and showed increased pericapsular fibrosis. We conclude that pMSC derived from juvenile porcine exocrine pancreas improves insulin secretion of ICC by direct cell‐cell contact. For transplantation purposes, the use of pMSC to support beta‐cell function will depend on the development of new anti‐fibrotic polymers and/or on genetically modified pigs with lower immunogenicity.

Multipotent Mesenchymal Stromal Cells Interact and Support Islet of Langerhans Viability and Function

“…Co-encapsulation studies using islets versus islets and MSC also showed beneficial effects on islet function (64)(65)(66). Intraperitoneally syngeneic transplantation of co-encapsulated islets and MSCs showed significantly lower glycaemia compared to islets encapsulated alone.…”

“…It is known that Notch1 downregulates the expression of several genes and transcription factors implicated in the development of endocrine cells and insulin ( 72 , 74 ). Juvenile porcine exocrine pancreas-derived MSCs (pMSCs) co-cultured with direct cell to cell contact of juvenile porcine ICCs significantly enhanced beta-cell function, suggesting that cell signaling via adhesion molecules are important ( 57 , 65 ). However, co-encapsulation of such ICCs with pMSCs do not effectively prevent PFO and graft survival was rapidly impaired after transplantation of capsules in immunocompetent mice.…”

“…Therefore, further research is required to enable efficient long-term survival of encapsulated juvenile porcine islets. Possible approaches being evaluation of modified alginate chemical composition ( 75 ) or the use of different anti-fibrotic polymers ( 65 ).…”

Updateon xenotransplantation for May/June 2021

“…To determine what role multipotent MSCs may play in graft function, Montanari et al. co‐cultured juvenile porcine islet cell clusters (ICCs) with porcine‐derived multipotent MSCs (pMSCs) both with and without cell–cell contact using the transwell system 42 . They encapsulated ICCs in Ca‐alg microspheres (MS) both with and without pMSCs and transplanted into diabetic and immunocompetent mice.…”

Two in One: Use of Divalent Manganese Ions as Both Cross-Linking and MRI Contrast Agent for Intrathecal Injection of Hydrogel-Embedded Stem Cells

“…Another attractive feature of manganese (II) ions is their cross-linking ability triggering polymerization of the alginate. Alginates as bioscaffolds have been used to support transplanted cells [ 12 ]. They are biodegradable, of low immunogenicity, and are injectable [ 13 , 14 , 15 , 16 ].…”