Beneficial effect of recombinant rC1rC2 collagenases on human islet function: Efficacy of low‐dose enzymes on pancreas digestion and yield

• Published in: American journal of transplantation Vol. 18; no. 2; pp. 478 - 485
• Main Authors: Loganathan, Gopalakrishnan, Subhashree, Venugopal, Breite, Andrew G., Tucker, William W., Narayanan, Siddharth, Dhanasekaran, Maheswaran, Mokshagundam, SriPrakash, Green, Michael L., Hughes, Michael G., Williams, Stuart K., Dwulet, Francis E., McCarthy, Robert C., Balamurugan, Appakalai N.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.02.2018
• Subjects: Adult; Animals; Cells, Cultured; Collagen; Collagenase; Collagenases - administration & dosage; Diabetes Mellitus, Experimental - therapy; Enzymes; Female; Humans; Insulin; Insulin - metabolism; islet isolation; islet transplantation; Islets of Langerhans; Islets of Langerhans - cytology; Islets of Langerhans - physiology; Islets of Langerhans Transplantation; Male; Matrix Metalloproteinase 8 - administration & dosage; Mice; Mice, Nude; Pancreas; Pancreas - metabolism; Recombinant Proteins - administration & dosage; Rodents; Scanning electron microscopy; translational research/science; Young Adult; islet transplantation; translational research/science; islet isolation; islets of Langerhans
• ISSN: 1600-6135; 1600-6143
• DOI: 10.1111/ajt.14542

A high number of human islets can be isolated by using modern purified tissue dissociation enzymes; however, this requires the use of >20 Wunsch units (WU)/g of pancreas for digestion. Attempts to reduce this dose have resulted in pancreas underdigestion and poor islet recovery but improved islet function. In this study, we achieved a high number of functional islets using a low dose of recombinant collagenase enzyme mixture (RCEM‐1200 WU rC2 and 10 million collagen‐degrading activity [CDA] U of rC1 containing about 209 mg of collagenase to digest a 100‐g pancreas). The collagenase dose used in these isolations is about 42% of the natural collagenase enzyme mixture (NCEM) dose commonly used to digest a 100‐g pancreas. Low‐dose RCEM was efficient in digesting entire pancreases to obtain higher yield (5535 ± 830 and 2582 ± 925 islet equivalent/g, P < .05) and less undigested tissue (16.7 ± 5% and 37.8 ± 3%, P < .05) compared with low‐dose NCEM (12WU/g). Additionally, low‐dose RCEM islets retained better morphology (confirmed with scanning electron microscopy) and higher in vitro basal insulin release (2391 ± 1342 and 1778 ± 978 μU/mL; P < .05) compared with standard‐dose NCEM. Nude mouse bioassay demonstrated better islet function for low‐dose RCEM (area under the curve [AUC] 24 968) compared with low‐dose (AUC–38 225) or standard‐dose NCEM (AUC–38 685), P < .05. This is the first report indicating that islet function can be improved by using low‐dose rC1rC2 (RCEM). This study evaluates the efficacy of low‐dose recombinant collagenase enzyme mixture and identifies its beneficial effect on human islet yield and function.