title: The Choice of Enzyme for Human Pancreas Digestion is a Critical Factor for Increasing the Success of Islet Isolation.
abstract: BACKGROUND
  We evaluated three commercially available enzymes for pancreatic digestion by comparing key parameters during the islet isolation process, as well as islet quality post-isolation.
  
  
  METHODS
  Retrospectively compared and analyzed islet isolations from pancreata using three different enzyme groups: Liberase HI (n=63), Collagenase NB1/Neutral Protease (NP) (n=43), and Liberase Mammalian Tissue Free Collagenase/Thermolysin (MTF C/T) (n=115). A standardized islet isolation and purification method was used. Islet quality assessment was carried out using islet count, viability,in vitroglucose-stimulated insulin secretion (GSIS), glucose-stimulated oxygen consumption rate (ΔOCR), andin vivotransplantation model in mice.
  
  
  RESULTS
  Donor characteristics were not significantly different among the three enzyme groups used in terms of age, sex, hospital stay duration, cause of death, body mass index (BMI), hemoglobin A1c (HbA1c), cold ischemia time (CIT), and pancreas weight. Digestion efficacy (percentage of digested tissue by weight) was significantly higher in the Liberase MTF C/T group (73.5 ± 1.5 %) when compared to the Liberase HI group (63.6 ± 2.3 %) (p<0.001) and the Collagenase NB1/NP group (61.7 ± 2.9%) (p<0.001). The stimulation index for GSIS was significantly higher in the Liberase MTF C/T group (5.3 ± 0.5) as compared to the Liberase HI (2.9 ± 0.2) (p<0.0001) and the Collagenase NB1/NP (3.6 ± 2.9) (p=0.012) groups. Furthermore, the Liberase MTF C/T enzymes showed the highest success rate of transplantation in diabetic NOD Scid mice (65%), which was significantly higher than the Liberase HI (42%, p=0.001) and the Collagenase NB1/NP enzymes (41%, p<0.001).
  
  
  CONCLUSIONS
  Liberase MTF C/T is superior to Liberase HI and Collagenase NB1/NP in terms of digestion efficacy and glucose-stimulated insulin secretionin vitro. Moreover, Liberase MTF C/T had a significantly higher success rate of transplantation in diabetic NOD Scid mice compared to Liberase HI and Collagenase NB1/NP enzymes.
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Meirigeng
authors.initials: M
authors.lastname: Qi
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Luis
authors.initials: L
authors.lastname: Valiente
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Brian
authors.initials: B
authors.lastname: McFadden
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Keiko
authors.initials: K
authors.lastname: Omori
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Shiela
authors.initials: S
authors.lastname: Bilbao
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Jemily
authors.initials: J
authors.lastname: Juan
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rawson
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Stephen
authors.initials: S
authors.lastname: Scott
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Kevin
authors.initials: K
authors.lastname: Ferreri
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mullen
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Mohamed
authors.initials: M
authors.lastname: El-Shahawy
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Donald
authors.initials: D
authors.lastname: Dafoe
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Fouad
authors.initials: F
authors.lastname: Kandeel
authors.affiliation: Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolism Research Institute, Beckman Research Institute of the City of Hope.
authors.forename: Ismail H
authors.initials: IH
authors.lastname: Al-Abdullah