title: Increased albumin concentration reduces apoptosis and improves functionality of human islets.
abstract: Providing sufficient islet mass is important for successful islet transplantation. Apoptosis plays a major role in post-isolation islet cell death, and prevention of apoptosis could improve transplant outcomes. The purpose of this study was to determine whether increased concentration of human albumin (HA) in pre-transplantation culture of human islets would reduce apoptosis. Human islets were cultured in CMRL with 1.5 or 5% of HA for 24 h and apoptosis was evaluated indirectly by measuring caspase 3 activity and tetramethylrhodamine-ethyl-ester (TMRE) in dissociated islets. Islet function and viability were evaluated. Islets cultured in higher albumin concentration presented with lower caspase 3 activity (43.9 +/- 3.9 vs. 67.4 +/- 11.1, p = 0.011), and had increased insulin secretory capacity (Stimulation index 3.76 +/- 0.91 vs 1.23 +/- 0.21, p = 0.023). We conclude that an increase in albumin concentration can prevent apoptosis in isolated human islets. These findings may have implications for islet transplant outcomes.
authors.affiliation: Division of Transplantation, Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Barbaro
authors.forename: Joseph
authors.initials: J
authors.lastname: Kuechle
authors.forename: Payam
authors.initials: P
authors.lastname: Salehi
authors.forename: Lisette
authors.initials: L
authors.lastname: Rodriguez
authors.forename: Merigeng
authors.initials: M
authors.lastname: Qi
authors.forename: Antonio
authors.initials: A
authors.lastname: Gangemi
authors.forename: Enrico
authors.initials: E
authors.lastname: Benedetti
authors.forename: José
authors.initials: J
authors.lastname: Oberholzer
mesh_terms: D000418:Albumins / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*
chemical_list: D000418:Albumins; D007328:Insulin; D053148:Caspase 3; D005947:Glucose