title: Defective lymphocyte caspase-3 expression in type 1 diabetes mellitus.
abstract: OBJECTIVE
  Activation-induced cell death (AICD) is a major mechanism in the regulation of peripheral tolerance and its impairment can determine the development of autoimmunity. In the present study, in order to evaluate the role of caspase-3 in type 1 diabetes mellitus (T1DM) AICD, caspase-3 expression was analyzed in peripheral blood lymphocytes from 37 new onset T1DM patients and from 36 normal control subjects (NC) in resting conditions and after anti-Fas-triggered apoptosis.
  
  
  METHODS
  Caspase-3 expression was determined by semiquantitative RT-PCR and Western blot. Apoptosis was induced in activated lymphocytes by anti-Fas monoclonal antibody and quantified by flow cytometry and morphological analysis.
  
  
  RESULTS
  Caspase-3 mRNA expression was reduced in resting lymphocytes in 18/37 T1DM patients and in 1/36 NC (P < 0.01). Patients studied for both Fas-mediated AICD and caspase-3 mRNA expression revealed that a reduced caspase-3 mRNA expression in resting lymphocytes occurred in all patients showing resistance to Fas-mediated apoptosis (T1DM vs NC, P < 0.02) with the exception of 3 patients who exhibited normal caspase-3 expression levels. Caspase-3 protein analysis confirmed mRNA data and showed an impaired expression of caspase-3 active form in T1DM subjects compared with NC.
  
  
  CONCLUSIONS
  Our data show that defective expression and function of caspase-3 in peripheral lymphocytes of T1DM patients may contribute to the development of AICD resistance in type 1 diabetes.
authors.affiliation: Department of Clinical Sciences-Endocrinology, University La Sapienza, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Vendrame
authors.forename: Carmela
authors.initials: C
authors.lastname: Santangelo
authors.forename: Roberta
authors.initials: R
authors.lastname: Misasi
authors.forename: Sabrina
authors.initials: S
authors.lastname: Dionisi
authors.forename: Chiara
authors.initials: C
authors.lastname: Gizzi
authors.forename: Massimo
authors.initials: M
authors.lastname: Realacci
authors.forename: Daniele
authors.initials: D
authors.lastname: Grassetti
authors.forename: Umberto
authors.initials: U
authors.lastname: Di Mario
authors.forename: Francesco
authors.initials: F
authors.lastname: Dotta
mesh_terms: D000293:Adolescent; D000328:Adult; D017209:Apoptosis / Q000502:physiology*; D053148:Caspase 3; D020169:Caspases / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000201:enzymology*; D005260:Female; D006801:Humans; D015151:Immunoblotting; D008213:Lymphocyte Activation; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000201:enzymology*; D019014:fas Receptor / Q000096:biosynthesis / Q000097:blood
chemical_list: D012333:RNA, Messenger; D019014:fas Receptor; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases