Three-dimensional scaffolds reduce islet amyloid formation and enhance survival and function of cultured human islets.
Islet transplantation provides a promising approach for treatment of type 1 diabetes mellitus. Amyloid formation and loss of extracellular matrix are two nonimmune factors contributing to death of isolated human islets. We tested the effects of two types of three-dimensional scaffolds, collagen matrix (CM) and fibroblast-populated collagen matrix (FPCM), on amyloid formation, viability, and function of isolated islets. Islets from cadaveric donors were cultured in FPCM, CM, or two-dimensional plate (2D) for 7 days. After 7 days, compared with the 2D culture condition, CM and FPCM markedly reduced amyloid formation of cultured islets and decreased apoptotic β-cell rate by ∼75%. IL-1β and Fas levels were also reduced in scaffold-embedded islets. Furthermore, β/α cell ratios were increased by ∼18% and ∼36% in CM- and FPCM-embedded islets, respectively. Insulin content and insulin response to elevated glucose were also enhanced by both three-dimensional scaffolds. Moreover, culture in CM and FPCM (but not 2D) preserved insulin, GLUT-2, and PDX-1 mRNA expression. FPCM-embedded islets had significantly higher insulin response and lower amyloid formation than CM-embedded islets. These findings suggest that three-dimensional scaffolds reduce amyloid formation and improve viability and function of human islets in vitro, and that CM and fibroblasts have additive effects in enhancing islet function and reducing amyloid formation. Using this strategy is likely to improve outcome in human islet transplantation.
Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
Yun
Y
Zhang
Reza B
RB
Jalili
Garth L
GL
Warnock
Ziliang
Z
Ao
Lucy
L
Marzban
Aziz
A
Ghahary
D000682:Amyloid / Q000378:metabolism*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002452:Cell Count; D004789:Enzyme Activation; D005786:Gene Expression Regulation; D050416:Glucagon-Secreting Cells / Q000378:metabolism / Q000473:pathology; D051273:Glucose Transporter Type 2 / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000201:enzymology / Q000473:pathology; D053583:Interleukin-1beta / Q000378:metabolism; D007515:Islets of Langerhans / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D046509:Tissue Culture Techniques / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*; D014022:Tissue Survival; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
D000682:Amyloid; C491901:FAS protein, human; D051273:Glucose Transporter Type 2; D018398:Homeodomain Proteins; D007328:Insulin; D053583:Interleukin-1beta; D012333:RNA, Messenger; C495680:SLC2A2 protein, human; D015534:Trans-Activators; D019014:fas Receptor; C084010:pancreatic and duodenal homeobox 1 protein; D053148:Caspase 3