Plasticity and Aggregation of Juvenile Porcine Islets in Modified Culture: Preliminary Observations.
Diabetes is a major health problem worldwide, and there is substantial interest in developing xenogeneic islet transplantation as a potential treatment. The potential to relieve the demand on an inadequate supply of human pancreata is dependent upon the efficiency of techniques for isolating and culturing islets from the source pancreata. Porcine islets are favored for xenotransplantation, but mature pigs (>2 years) present logistic and economic challenges, and young pigs (3-6 months) have not yet proven to be an adequate source. In this study, islets were isolated from 20 juvenile porcine pancreata (~3 months; 25 kg Yorkshire pigs) immediately following procurement or after 24 h of hypothermic machine perfusion (HMP) preservation. The resulting islet preparations were characterized using a battery of tests during culture in silicone rubber membrane flasks. Islet biology assessment included oxygen consumption, insulin secretion, histopathology, and in vivo function. Islet yields were highest from HMP-preserved pancreata (2,242 ± 449 IEQ/g). All preparations comprised a high proportion (>90%) of small islets (<100 μm), and purity was on average 63 ± 6%. Morphologically, islets appeared as clusters on day 0, loosely disaggregated structures at day 1, and transitioned to aggregated structures comprising both exocrine and endocrine cells by day 6. Histopathology confirmed both insulin and glucagon staining in cultures and grafts excised after transplantation in mice. Nuclear staining (Ki-67) confirmed mitotic activity consistent with the observed plasticity of these structures. Metabolic integrity was demonstrated by oxygen consumption rates = 175 ± 16 nmol/min/mg DNA, and physiological function was intact by glucose stimulation after 6-8 days in culture. In vivo function was confirmed with blood glucose control achieved in nearly 50% (8/17) of transplants. Preparation and culture of juvenile porcine islets as a source for islet transplantation require specialized conditions. These immature islets undergo plasticity in culture and form fully functional multicellular structures. Further development of this method for culturing immature porcine islets is expected to generate small pancreatic tissue-derived organoids termed "pancreatites," as a therapeutic product from juvenile pigs for xenotransplantation and diabetes research.
Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, USA.|Sylvatica Biotech, LLC, N. Charleston, SC, USA.
Bradley P
BP
Weegman
Sylvatica Biotech, LLC, N. Charleston, SC, USA.|Tissue Testing Technologies, LLC, N. Charleston, SC, USA.|Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA.
Michael J
MJ
Taylor
Tissue Testing Technologies, LLC, N. Charleston, SC, USA.|LifePoint, Inc., Charleston, SC, USA.
Simona C
SC
Baicu
Department of Surgery, University of Minnesota, Minneapolis, MN, USA.
Kate
K
Mueller
Veterinary Population Medicine Department, University of Minnesota, St. Paul, MN, USA.
Timothy D
TD
O'brien
Wilson Wolf Manufacturing, New Brighton, MN, USA.
John
J
Wilson
Department of Surgery, University of Arizona, Tucson, AZ, USA.
Klearchos K
KK
Papas
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000473:pathology / Q000628:therapy; D005934:Glucagon / Q000378:metabolism; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000473:pathology; D016381:Islets of Langerhans Transplantation; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D018613:Microscopy, Confocal; D009924:Organ Culture Techniques; D010101:Oxygen Consumption; D010179:Pancreas / Q000166:cytology* / Q000473:pathology; D013552:Swine; D014183:Transplantation, Heterologous
D001786:Blood Glucose; D007328:Insulin; D019394:Ki-67 Antigen; D005934:Glucagon
Diabetes; Islet culture; Islet transplantation; Porcine islets; Xenotransplantation