title: Insulin degradation by acinar cell proteases creates a dysfunctional environment for human islets before/after transplantation: benefits of α-1 antitrypsin treatment.
abstract: BACKGROUND
  Pancreatic acinar cells are commonly cotransplanted along with islets during auto- and allotransplantations. The aims of this study were to identify how acinar cell proteases cause human islet cell loss before and after transplantation of impure islet preparations and to prevent islet loss and improve function with supplementation of α-1 antitrypsin (A1AT).
  
  
  METHODS
  Acinar cell protease activity, insulin levels, and percent islet loss were measured after culture of pure and impure clinical islet preparations. The effect of proteases on ultrastructure of islets and β-cell insulin granules were examined by transmission electron microscopy. The number of insulin granules and insulin-labeled immunogold particles were counted. The in vivo effect of proteases on islet function was studied by transplanting acinar cells adjacent to islet grafts in diabetic mice. The effects of A1AT culture supplementation on protease activity, insulin levels, and islet function were assessed in pure and impure islets.
  
  
  RESULTS
  Islet loss after culture was significantly higher in impure relative to pure preparations (30% vs. 14%, P<0.04). Lower islet purity was associated with increased protease activity and decreased insulin levels in culture supernatants. Reduced β-cell insulin granules and insulin degradation by proteases were confirmed by transmission electron microscopy. Transplantations in mice showed delayed islet graft function when acinar cells were transplanted adjacent to the islets under the kidney capsule. Supplementation of A1AT to impure islet cultures maintained islet cell mass, restored insulin levels, and preserved islet functional integrity.
  
  
  CONCLUSIONS
  Culture of impure human islet fractions in the presence of A1AT prevents insulin degradation and improves islet recovery.
authors.affiliation: Department of Surgery, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Gopalakrishnan
authors.initials: G
authors.lastname: Loganathan
authors.forename: Rajinder K
authors.initials: RK
authors.lastname: Dawra
authors.forename: Subbiah
authors.initials: S
authors.lastname: Pugazhenthi
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Guo
authors.forename: Sajjad M
authors.initials: SM
authors.lastname: Soltani
authors.forename: Alexander
authors.initials: A
authors.lastname: Wiseman
authors.forename: Mark A
authors.initials: MA
authors.lastname: Sanders
authors.forename: Klearchos K
authors.initials: KK
authors.lastname: Papas
authors.forename: Kumaravel
authors.initials: K
authors.lastname: Velayutham
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Saluja
authors.forename: David E R
authors.initials: DE
authors.lastname: Sutherland
authors.forename: Bernhard J
authors.initials: BJ
authors.lastname: Hering
authors.forename: A N
authors.initials: AN
authors.lastname: Balamurugan
mesh_terms: D061354:Acinar Cells / Q000166:cytology / Q000201:enzymology*; D000818:Animals; D002478:Cells, Cultured; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000601:surgery; D004195:Disease Models, Animal; D006085:Graft Survival / Q000187:drug effects; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007515:Islets of Langerhans / Q000166:cytology / Q000187:drug effects* / Q000503:physiopathology*; D016381:Islets of Langerhans Transplantation / Q000502:physiology*; D008297:Male; D051379:Mice; D008819:Mice, Nude; D010447:Peptide Hydrolases / Q000187:drug effects / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013311:Streptozocin / Q000009:adverse effects; D014183:Transplantation, Heterologous; D016896:Treatment Outcome; D000515:alpha 1-Antitrypsin / Q000494:pharmacology*
chemical_list: D007328:Insulin; D015842:Serine Proteinase Inhibitors; D000515:alpha 1-Antitrypsin; D013311:Streptozocin; D010447:Peptide Hydrolases
references.citation: Curr Diab Rep. 2009 Apr;9(2):100-2
references.pmid: 19323953
references.citation: Transplantation. 1998 Apr 27;65(8):1060-6
references.pmid: 9583866
references.citation: Transplant Proc. 2008 Mar;40(2):355-7
references.pmid: 18374065
references.citation: Int J Cancer. 1999 Jan 29;80(3):431-8
references.pmid: 9935186
references.citation: Transplantation. 1995 Oct 27;60(8):854-60
references.pmid: 7482747
references.citation: Am J Transplant. 2003 Jan;3(1):53-63
references.pmid: 12492711
references.citation: Transplant Proc. 2010 Jul-Aug;42(6):2055-7
references.pmid: 20692406
references.citation: Transplantation. 2010 Jun 15;89(11):1328-35
references.pmid: 20357700
references.citation: Transplant Proc. 2008 Mar;40(2):384-6
references.pmid: 18374076
references.citation: Transplantation. 1986 Feb;41(2):271-4
references.pmid: 3003979
references.citation: N Engl J Med. 1987 Apr 23;316(17):1055-62
references.pmid: 3494198
references.citation: Islets. 2010 May-Jun;2(3):185-9
references.pmid: 21099312
references.citation: Transplantation. 2010 Apr 27;89(8):954-61
references.pmid: 20300051
references.citation: Cell Transplant. 2004;13(6):605-17
references.pmid: 15648731
references.citation: Transplant Proc. 2008 Mar;40(2):390-2
references.pmid: 18374078
references.citation: Diabetologia. 1985 Aug;28(8):485-93
references.pmid: 3902539
references.citation: Pancreas. 2003 Aug;27(2):167-73
references.pmid: 12883266
references.citation: Transplant Proc. 2002 Nov;34(7):2700-1
references.pmid: 12431580
references.citation: Pediatr Diabetes. 2010 Jun;11(4):227-34
references.pmid: 19708905
references.citation: J Surg Res. 1988 Nov;45(5):432-42
references.pmid: 3141720
references.citation: Transplantation. 2008 Dec 27;86(12):1783-8
references.pmid: 19104422
references.citation: Proc Natl Acad Sci U S A. 2008 Oct 21;105(42):16236-41
references.pmid: 18852465
references.citation: J Appl Physiol (1985). 1987 Nov;63(5):2015-23
references.pmid: 3500941
references.citation: Neurosci Lett. 1995 Oct 13;199(1):37-40
references.pmid: 8584221
references.citation: Diabetes Metab Rev. 1996 Jul;12(2):137-50
references.pmid: 8877283
references.citation: J Clin Invest. 1998 Aug 15;102(4):783-91
references.pmid: 9710447
references.citation: Biotechnol Bioeng. 2007 Dec 1;98(5):1071-82
references.pmid: 17497731
references.citation: Cell Biochem Biophys. 2004;40(3 Suppl):49-54
references.pmid: 15289642
references.citation: Transplantation. 2003 Feb 27;75(4):462-6
references.pmid: 12605110
references.citation: Transplant Proc. 1979 Mar;11(1):336-40
references.pmid: 109963
references.citation: J Hepatobiliary Pancreat Surg. 2005;12(3):227-30
references.pmid: 15995811
references.citation: JAMA. 2005 Feb 16;293(7):830-5
references.pmid: 15713772
references.citation: Proc Natl Acad Sci U S A. 2005 Aug 23;102(34):12153-8
references.pmid: 16093309
references.citation: Transplantation. 2001 Aug 27;72(4):565-70
references.pmid: 11544413
references.citation: Eur J Biochem. 1988 Feb 15;172(1):17-25
references.pmid: 3278905
references.citation: Proc Natl Acad Sci U S A. 2005 Sep 6;102(36):12651-2
references.pmid: 16129823
references.citation: J Endocrinol. 1999 Jun;161(3):357-64
references.pmid: 10333538
references.citation: Proc Natl Acad Sci U S A. 2008 Oct 21;105(42):16242-7
references.pmid: 18852471
references.citation: Transpl Int. 2010 Mar 1;23(3):259-65
references.pmid: 19821955
references.citation: Am J Transplant. 2005 Aug;5(8):2037-46
references.pmid: 15996257
references.citation: Transpl Int. 2008 Nov;21(11):1029-35
references.pmid: 18564983
references.citation: Diabetes. 2007 May;56(5):1316-23
references.pmid: 17360983