Aims/hypothesis Pancreatic beta cells have highly developed endoplasmic reticulum (ER) due to their role in insulin secretion. Since ER stress has been associated with beta cell dysfunction, we studied several features of beta cell ER in human type 2 diabetes. Methods Pancreatic samples and/or isolated islets from non-diabetic controls (ND) and type 2 diabetes patients were evaluated for insulin secretion, apoptosis (electron microscopy and ELISA), morphometric ER assessment (electron microscopy), and expression of ER stress markers in beta cell prepared by laser capture microdissection and in isolated islets.Results Insulin release was lower and beta cell apoptosis higher in type 2 diabetes than ND islets. ER density volume was significantly increased in type 2 diabetes beta cells. Expression of alpha-mannosidase (also known as mannosidase, alpha, class 1A, member 1) and UDP-glucose glycoprotein glucosyl transferase like 2 (UGCGL2), assessed by microarray and/or real-time reverse transcriptase polymerase chain reaction (RT-PCR), differed between ND and type 2 diabetes beta cells. Expression of immunoglobulin heavy chain binding protein (BiP, also known as heat shock 70 kDa protein 5 [glucose-regulated protein, 78 kDa] [HSPA5]), X-box binding protein 1 (XBP-1, also known as XBP1) and C/EBP homologous protein (CHOP, also known as damage-inducible transcript 3 [DDIT3]) was not higher in type 2 diabetes beta cell or isolated islets cultured at 5.5 mmol/l glucose (microarray and real-time RT-PCR) than in ND samples. When islets were cultured for 24 h at 11

Aims/hypothesis Beta cell loss contributes to type 2 diabetes, with increased apoptosis representing an underlying mechanism. Autophagy, i.e. the physiological degradation of damaged organelles and proteins, may, if altered, be associated with a distinct form of cell death. We studied several features of autophagy in beta cells from type 2 diabetic patients and assessed the role of metabolic perturbation and pharmacological intervention. Methods Pancreatic samples were obtained from organ donors and isolated islets prepared both by collagenase digestion and density gradient centrifugation. Beta cell morphology and morphometry were studied by electron microscopy. Gene expression studies were performed by quantitative RT-PCR. Results Using electron microscopy, we observed more dead beta cells in diabetic (2.24±0.53%) than control (0.66± 0.52%) samples (p < 0.01). Massive vacuole overload (suggesting altered autophagy) was associated with 1.18± 0.54% dead beta cells in type 2 diabetic samples and with 0.36±0.26% in control samples (p<0.05). Density volume of autophagic vacuoles and autophagosomes was significantly higher in diabetic beta cells. Unchanged gene expression of beclin-1 and ATG1 (also known as ULK1), and reduced transcription of LAMP2 and cathepsin B and D was observed in type 2 diabetic islets. Exposure of nondiabetic islets to increased NEFA concentration led to a marked increase of vacuole accumulation, together with enhanced beta cell death, which was associated with decreased LAMP2 expression. Metformin ameliorated autophagy alterations in diabetic beta cells and beta cells exposed to NEFA, a process associated with normalisation of LAMP2 expression. Conclusions/interpretation Beta cells in human type 2 diabetes have signs of altered autophagy, which may contribute to loss of beta cell mass. To preserve beta cell mass in diabetic patients, it may be necessary to target multiple cell-death pathways.

Aims/hypothesis Glucagon-like peptide 1 (GLP-1) is a major incretin, mainly produced by the intestinal L cells, with beneficial actions on pancreatic beta cells. However, while in vivo only very small amounts of GLP-1 reach the pancreas in bioactive form, some observations indicate that GLP-1 may also be produced in the islets. We performed comprehensive morphological, functional and molecular studies to evaluate the presence and various features of a local GLP-1 system in human pancreatic islet cells, including those from type 2 diabetic patients. MethodsThe presence of insulin, glucagon, GLP-1, proconvertase (PC) 1/3 and PC2 was determined in human pancreas by immunohistochemistry with confocal microscopy. Islets were isolated from non-diabetic and type 2 diabetic donors. GLP-1 protein abundance was evaluated by immunoblotting and matrix-assisted laser desorption-ionisation-time of flight (MALDI-TOF) mass spectrometry. Single alpha and beta cell suspensions were obtained by enzymatic dissociation and FACS sorting. Glucagon and GLP-1 release were measured in response to nutrients. Diabetologia (2012) 55:3262-3272 DOI 10.1007/s00125-012-2716 Electronic supplementary material The online version of this article (doi:10.1007/s00125-012-2716-9) contains peer-reviewed but unedited supplementary material, which is available to authorised users. Results Confocal microscopy showed the presence of GLP-1-like and PC1/3 immunoreactivity in subsets of alpha cells, whereas GLP-1 was not observed in beta cells. The presence of GLP-1 in isolated islets was confirmed by immunoblotting, followed by mass spectrometry. Isolated islets and alpha (but not beta) cell fractions released GLP-1, which was regulated by glucose and arginine. PC1/3 (also known as PCSK1) gene expression was shown in alpha cells. GLP-1 release was significantly higher from type 2 diabetic than from nondiabetic isolated islets. Conclusions/interpretation We have shown the presence of a functionally competent GLP-1 system in human pancreatic islets, which resides in alpha cells and might be modulated by type 2 diabetes.

Aims/hypothesisPancreatic islet beta cell failure causes type 2 diabetes in humans. To identify transcriptomic changes in type 2 diabetic islets, the Innovative Medicines Initiative for Diabetes: Improving beta-cell function and identification of diagnostic biomarkers for treatment monitoring in Diabetes (IMIDIA) consortium (www.imidia.org) established a comprehensive, unique multicentre biobank of human islets and pancreas tissues from organ donors and metabolically phenotyped pancreatectomised patients (PPP).MethodsAffymetrix microarrays were used to assess the islet transcriptome of islets isolated either by enzymatic digestion from 103 organ donors (OD), including 84 non-diabetic and 19 type 2 diabetic individuals, or by laser capture microdissection (LCM) from surgical specimens of 103 PPP, including 32 non-diabetic, 36 with type 2 diabetes, 15 with impaired glucose tolerance (IGT) and 20 with recent-onset diabetes (<1 year), conceivably secondary to the pancreatic disorder leading to surgery (type 3c diabetes). Bioinformatics tools were used to (1) compare the islet transcriptome of type 2 diabetic vs non-diabetic OD and PPP as well as vs IGT and type 3c diabetes within the PPP group; and (2) identify transcription factors driving gene co-expression modules correlated with insulin secretion ex vivo and glucose tolerance in vivo. Selected genes of interest were validated for their expression and function in beta cells.ResultsComparative transcriptomic analysis identified 19 genes differentially expressed (false discovery rate ≤0.05, fold change ≥1.5) in type 2 diabetic vs non-diabetic islets from OD and PPP. Nine out of these 19 dysregulated genes were not previously reported to be dysregulated in type 2 diabetic islets. Signature genes included TMEM37, which inhibited Ca2+-influx and insulin secretion in beta cells, and ARG2 and PPP1R1A, which promoted insulin secretion. Systems biology approaches identified HNF1A, PDX1 and REST as drivers of gene co-expression modules correlated with impaired insulin secretion or glucose tolerance, and 14 out of 19 differentially expressed type 2 diabetic islet signature genes were enriched in these modules. None of these signature genes was significantly dysregulated in islets of PPP with impaired glucose tolerance or type 3c diabetes.Conclusions/interpretationThese studies enabled the stringent definition of a novel transcriptomic signature of type 2 diabetic islets, regardless of islet source and isolation procedure. Lack of this signature in islets from PPP with IGT or type 3c diabetes indicates differences possibly due to peculiarities of these hyperglycaemic conditions and/or a role for duration and severity of hyperglycaemia. Alternatively, these transcriptomic changes capture, but may not precede, beta cell failure.Electronic supplementary materialThe online version of this article (10.1007/s00125-017-4500-3) contains peer-reviewed but unedited supplementary material, which is available to authorised users.

Older donors are a growing part of the total donor pool but no definite consensus exists on the limit of age for their acceptance. From November 1998 to January 2003, in a retrospective case-control multicenter study, we compared the outcome of 30 orthotopic liver transplantations (OLTs) with octogenarian donors and of 60 chronologically correlated OLTs performed with donors <40 years. The percentage of refusal was greater among older than younger donors (48.2 vs. 14.3%; p < 0.001). Cold ischemia was significantly shorter in the older than younger groups. Recipients with hepatocarcinoma and older age received octogenarian grafts more frequently. No differences were seen in post-operative complications and 6-month graft and patient survival. However, longterm survival was lower in patients transplanted with octogenarian donors (p = = 0.04). Interestingly, the mortality related to hepatitis C recurrence was greater in patients with octogenarian donors. Accordingly, the long-term survival of HCV-positive patients who received older grafts was lower than those receiving younger grafts (p = = 0.05). Octogenarian livers can be used safely but a careful donor evaluation and a short cold ischemia are required to prevent additional risk factors. However, hepatitis C recurrence is associated with a greater mortality in patients who received octogenarian grafts raising concerns whether to allocate these livers to HCV-positive recipients.

The GONO-FOLFOXIRI regimen allow an R0 surgery in approximately 1 out of 5 unselected patients with initially unresectable metastatic colorectal cancer, and the long-term survival of resected patients is considerable. Neoadjuvant FOLFOXIRI for 3-6 months is safe and not associated with severe liver injury.

Use of very old donors in liver transplantation (LT) is controversial because advanced donor age is associated with a higher risk for graft dysfunction and worse long-term results, especially for hepatitis C virus (HCV)-positive recipients. This was a retrospective, single-center review of primary, ABO-compatible LT performed between 2001 and 2010. Recipients were stratified in four groups based on donor age (<60 years; 60-69 years; 70-79 years and !80 years) and their outcomes were compared. A total of 842 patients were included: 348 (41.3%) with donors <60 years; 176 (20.9%) with donors 60-69 years; 233 (27.7%) with donors 70-79 years and 85 (10.1%) with donors !80 years. There was no difference across groups in terms of early ( 30 days) graft loss, and graft survival at 1 and 5 years was 90.5% and 78.6% for grafts <60 years; 88.6% and 81.3% for grafts 60-69 years; 87.6% and 75.1% for grafts 70-79 years and 84.7% and 77.1% for grafts !80 years (p ¼ 0.065). In the group !80 years, the 5-year graft survival was lower for HCV-positive versus HCV-negative recipients (62.4% vs. 85.6%, p ¼ 0.034). Based on our experience, grafts from donors !80 years may provide favorable results but require appropriate selection and allocation policies.

Aims/hypothesis Previous work has demonstrated that beta cell amount (whether measured as beta cell mass, beta cell volume or insulin-positive area) is decreased in type 2 diabetes; however, recent findings suggest that mechanisms other than death may contribute to beta cell failure in this disease. To better characterise beta cell mass and function in type 2 diabetes, we performed morphological, ultra-structural and functional studies using histological samples and isolated islets. Methods Pancreases from ten non-diabetic (ND) and ten matched type 2 diabetic organ donors were studied by insulin, glucagon and chromogranin A immunocytochemistry and electron microscopy (EM). Glucose-stimulated insulin secretion was assessed using isolated islets and studies were performed using independent ND islet preparations after 24 h exposure to 22.2 mmol/l glucose. Results Immunocytochemistry showed that the fractional islet insulin-positive area was lower in type 2 diabetic islets (54.9± 6.3% vs 72.1±8.7%, p <0.01), whereas glucagon (23.3 ± 5.4% vs 20.2 ± 5.3%) and chromogranin A (86.4±6.1% vs 89.0±5.5%) staining was similar between the two groups. EM showed that the proportion of beta cells in type 2 diabetic islets was only marginally decreased; marked beta cell degranulation was found in diabetic beta cells; these findings were all reproduced after exposing isolated ND islets to high glucose. Glucose-stimulated insulin secretion was 40-50% lower from type 2 diabetic islets ( p <0.01), which again was mimicked by culturing non-diabetic islets in high glucose. Conclusions/interpretation These results suggest that, at least in subgroups of type 2 diabetic patients, the loss of beta cells as assessed so far might be overestimated, possibly due to changes in beta cell phenotype other than death, also contributing to beta cell failure in type 2 diabetes.