title: HMGB1 Is Increased by CFTR Loss of Function, Is Lowered by Insulin, and Increases In Vivo at Onset of CFRD.
abstract: BACKGROUND
  Cystic fibrosis-related diabetes (CFRD) is associated with worsening of inflammation and infections, and the beginning of insulin treatment is debated.
  
  
  OBJECTIVE
  To verify high-mobility group box 1 protein (HMGB1) levels in CF patients according to glucose tolerance state, and analyze relationships with insulin secretion and resistance. To verify, in an in vitro model, whether HMGB1 gene expression and protein content were affected by insulin administration and whether these changes were dependent on CF transmembrane conductance regulator (CFTR) loss of function.
  
  
  METHODS
  Forty-three patients in stable clinical conditions and 35 age- and sex-matched controls were enrolled. Glucose tolerance was established in patients based on a 5 point oral glucose tolerance test (OGTT). Fasting glucose to insulin ratio (FGIR), HOMA-IR index, whole-body insulin sensitivity index (WIBISI), and the areas under the curve for glucose (AUCG) and insulin (AUCI) were calculated. HMGB1 was assayed in serum, in cell lysates and conditioned media using a specific ELISA kit. For the in vitro study we used CFBE41o- cells, homozygous for the F508del mutation, and 16HBE14o- as non-CF control. HMGB1 gene expression was studied by real-time RT-PCR. Cells were stimulated with insulin at 2.5 and 5 ng/mL. The CFTR inhibitor 172 and CFTR gene silencing were used to induce CFTR loss of function in 16HBE14o- cells.
  
  
  RESULTS
  HMGB1 levels were increased at onset of CFRD (5.04 ± 1.2 vs 2.7 ± 0.3 ng/mL in controls; P < .05) and correlated with FGIR (R = +0.43; P = .038), and AUCI (R = +0.43; P = .013). CFTR loss of function in the 16HBE14o- cells increased HMGB1 and was lowered by insulin.
  
  
  CONCLUSIONS
  HMGB1 was increased in CF patients with deranging glucose metabolism and showed relationships with indexes of glucose metabolism. The increase in HMGB1 was related to CFTR loss of function, and insulin lowered HMGB1. Further research is required to verify whether HMGB1 could potentially be a candidate marker of onset of CFRD and to establish when to start insulin treatment.
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Montanini
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cirillo
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Arianna
authors.initials: A
authors.lastname: Smerieri
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Pisi
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Giardino
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: d'Apolito
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Spaggiari
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Bernasconi
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Amarri
authors.affiliation: Department of Pediatrics (L.M., A.S., G.P., C.S., S.B.), University Hospital of Parma, 43126 Parma, Italy; Department of Pediatrics (F.C., S.A., M.E.S.), Istituto di Ricovero e Cura a Carattere Scientifico-Arcispedale Santa Maria Nuova, 42123 Reggio Emilia, Italy; and Department of Clinical and Experimental Medicine (I.G, M.d.), University of Foggia, University Hospital of Foggia, 71122, Foggia, Italy.
authors.forename: Maria Elisabeth
authors.initials: ME
authors.lastname: Street
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001786:Blood Glucose / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D002648:Child; D003550:Cystic Fibrosis / Q000150:complications / Q000235:genetics* / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000502:physiology; D003920:Diabetes Mellitus / Q000235:genetics* / Q000378:metabolism; D005260:Female; D024243:HMGB1 Protein / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D034622:RNA Interference / Q000502:physiology; D034741:RNA, Small Interfering / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; C505032:CFTR protein, human; D024243:HMGB1 Protein; C585491:HMGB1 protein, human; D007328:Insulin; D034741:RNA, Small Interfering; D019005:Cystic Fibrosis Transmembrane Conductance Regulator