Molecular role of TGF-beta, secreted from a new type of CD4+ suppressor T cell, NY4.2, in the prevention of autoimmune IDDM in NOD mice.

Science.gov (United States)

Han, H S; Jun, H S; Utsugi, T; Yoon, J W

1997-06-01

A new type of CD4+ T cell clone (NY4.2) isolated from pancreatic islet-infiltrated lymphocytes of acutely diabetic non-obese diabetic (NOD) mice prevents the development of insulin-dependent diabetes mellitus (IDDM) in NOD mice, as well as the recurrence of autoimmune diabetes in syngeneic islet-transplanted NOD mice. It has been demonstrated that the cytokine TGF-beta, secreted from the cells of this clone, is the substance which prevents autoimmune IDDM. This investigation was initiated to determine the molecular role TGF-beta plays in the prevention of autoimmune IDDM by determining its effect on IL-2-induced signal transduction in Con A-activated NOD mouse splenocytes and HT-2 cells. First, we determined whether TGF-beta, secreted from NY4.2 T cells, inhibits IL-2-dependent T cell proliferation in HT-2 cells (IL-2-dependent T cell line) and NOD splenocytes. We found that TGF-beta suppresses IL-2-dependent T cell proliferation. Second, we determined whether TGF-beta inhibits the activation of Janus kinases (JAKs), as well as signal transducers and activators of transcription (STAT) proteins, involved in an IL-2-induced signalling pathway that normally leads to the proliferation of T cells. We found that TGF-beta inhibited tyrosine phosphorylation of JAK1, JAK3, STAT3 and STAT5 in Con A blasts from NOD splenocytes and HT-2 cells. Third, we examined whether TGF-beta inhibits the cooperation between STAT proteins and mitogen-activated protein kinase (MAPK), especially extracellular signal-regulated kinase 2 (ERK2). We found that TGF-beta inhibited the association of STAT3 and STAT5 with ERK2 in Con A blasts from NOD splenocytes and HT-2 cells. On the basis of these observations, we conclude that TGF-beta may interfere with signal transduction via inhibition of the IL-2-induced JAK/STAT pathway and inhibition of the association of STAT proteins with ERK2 in T cells from NOD splenocytes, resulting in the inhibition of IL-2-dependent T cell proliferation. TGF-beta

Management strategies for autoimmune pancreatitis.

Science.gov (United States)

Kamisawa, Terumi; Takuma, Kensuke; Hara, Seiichi; Tabata, Taku; Kuruma, Sawako; Inaba, Yoshihiko; Gopalakrishna, Rajesh; Egawa, Naoto; Itokawa, Fumihide; Itoi, Takao

2011-10-01

Autoimmune pancreatitis (AIP) is a newly developed concept for a peculiar type of pancreatitis, and at present is recognized as a pancreatic lesion reflecting IgG4-related systemic disease. It is of utmost importance to differentiate AIP from pancreatic cancer to avoid unnecessary surgery. The current management strategies for AIP, including its clinical features, diagnostic criteria, clinical subtypes, steroid therapy and prognosis are discussed, based on our 66 AIP cases and papers searched in PubMed from 1992 to March 2011, using the term 'autoimmune pancreatitis'. A new clinicopathological entity, an 'IgG4-related sclerosing disease' is also mentioned. AIP should be considered in the differential diagnosis in elderly male patients presented with obstructive jaundice and pancreatic mass. Steroids are a standard therapy for AIP, but their regimen including maintenance therapy should be evaluated in prospective trials.

Autoimmune pancreatitis in an 11-year-old boy

International Nuclear Information System (INIS)

Refaat, Rania; Harth, Marc; Proschek, Petra; Lindemayr, Sebastian; Vogl, Thomas J.

2009-01-01

We report a case of histopathologically proven autoimmune pancreatitis in an 11-year-old boy. Abdominal US and MRI showed a focal swelling of the pancreatic head, the latter also showing delayed contrast enhancement. There was diffuse irregular pancreatic duct narrowing, compression of the intrapancreatic common bile duct, and mild proximal biliary dilatation on MR cholangiopancreatography. Laboratory results revealed normal serum IgG and subclass 4 with negative autoimmune antibodies, and slightly elevated carbohydrate antigen 19-9. This highlights the differentiation of autoimmune pancreatitis from pancreatic head cancer and, to a lesser extent, other forms of pancreatitis in children. (orig.)

Autoimmune pancreatitis in an 11-year-old boy

Energy Technology Data Exchange (ETDEWEB)

Refaat, Rania [Johann-Wolfgang-Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Ain Shams University, Department of Diagnostic and Interventional Radiology, Cairo (Egypt); Harth, Marc; Proschek, Petra; Lindemayr, Sebastian; Vogl, Thomas J. [Johann-Wolfgang-Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany)

2009-04-15

We report a case of histopathologically proven autoimmune pancreatitis in an 11-year-old boy. Abdominal US and MRI showed a focal swelling of the pancreatic head, the latter also showing delayed contrast enhancement. There was diffuse irregular pancreatic duct narrowing, compression of the intrapancreatic common bile duct, and mild proximal biliary dilatation on MR cholangiopancreatography. Laboratory results revealed normal serum IgG and subclass 4 with negative autoimmune antibodies, and slightly elevated carbohydrate antigen 19-9. This highlights the differentiation of autoimmune pancreatitis from pancreatic head cancer and, to a lesser extent, other forms of pancreatitis in children. (orig.)

Cystic Lesions in Autoimmune Pancreatitis

Directory of Open Access Journals (Sweden)

Macarena Gompertz

2015-11-01

Full Text Available Autoimmune pancreatitis (AIP can be chronic or recurrent, but frequently completely reversible after steroid treatment. A cystic lesion in AIP is a rare finding, and it can mimic a pancreatic cystic neoplasm. Difficulties in an exact diagnosis interfere with treatment, and surgery cannot be avoided in some cases. We report the history of a 63-year-old male presenting with jaundice and pruritus. AIP was confirmed by imaging and elevated IgG4 blood levels, and the patient completely recovered after corticosteroid therapy. One year later, he presented with a recurrent episode of AIP with elevated IgG4 levels, accompanied by the appearance of multiple intrapancreatic cystic lesions. All but 1 of these cysts disappeared after steroid treatment, but the remaining cyst in the pancreatic head was even somewhat larger 1 year later. Pancreatoduodenectomy was finally performed. Histology showed the wall of the cystic lesion to be fibrotic; the surrounding pancreatic tissue presented fibrosis, atrophy and lymphoplasmacytic infiltration by IgG4-positive cells, without malignant elements. Our case illustrates the rare possibility that cystic lesions can be part of AIP. These pseudocysts appear in the pancreatic segments involved in the autoimmune disease and can be a consequence of the local inflammation or related to ductal strictures. Steroid treatment should be initiated, after which these cysts can completely disappear with recovery from AIP. Surgical intervention may be necessary in some exceptional cases.

Re-exposure to beta cell autoantigens in pancreatic allograft recipients with preexisting beta cell autoantibodies.

Science.gov (United States)

Mujtaba, Muhammad Ahmad; Fridell, Jonathan; Book, Benita; Faiz, Sara; Sharfuddin, Asif; Wiebke, Eric; Rigby, Mark; Taber, Tim

2015-11-01

Re-exposure to beta cell autoantigens and its relevance in the presence of donor-specific antibodies (DSA) in pancreatic allograft recipients is not well known. Thirty-three patients requiring a pancreas transplant were enrolled in an IRB approved study. They underwent prospective monitoring for DSA and beta cell autoantibody (BCAA) levels to GAD65, insulinoma-associated antigen 2 (IA-2), insulin (micro-IAA [mIAA]), and islet-specific zinc transporter isoform-8 (ZnT8). Twenty-five (75.7%) had pre-transplant BCAA. Twenty had a single antibody (mIAA n = 15, GAD65 n = 5); five had two or more BCAA (GAD65 + mIAA n = 2, GAD65 + mIAA+IA-2 n = 2, GA65 + mIAA+IA-2 + ZnT8 = 1). No changes in GAD65 (p > 0.29), IA-2 (>0.16), and ZnT8 (p > 0.07) were observed between pre-transplant and post-transplant at 6 or 12 months. A decrease in mIAA from pre- to post-6 months (p BCAA was observed at one yr. Seven (21.0%) developed de novo DSA. The incidence of DSA was 24% in patients with BCAA vs. 25% in patients without BCAA (p = 0.69). Pancreatic allograft function of patients with vs. without BCAA, and with and without BCAA + DSA was comparable until last follow-up (three yr). Re-exposure to beta cell autoantigens by pancreas transplant may not lead to increased levels or development of new BCAA or pancreatic allograft dysfunction. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Pancreatic endocrine and exocrine function and salivary gland function in autoimmune pancreatitis before and after steroid therapy.

Science.gov (United States)

Kamisawa, Terumi; Egawa, Naoto; Inokuma, Shigeko; Tsuruta, Kouji; Okamoto, Atsutake; Kamata, Noriko; Nakamura, Teruo; Matsukawa, Masakatsu

2003-10-01

Autoimmune pancreatitis (AIP) is a distinct clinical entity in which an autoimmune mechanism may be involved in pathogenesis. To investigate salivary gland function in addition to pancreatic endocrine and exocrine function in patients with AIP, and to determine changes occurring after steroid therapy. Fasting serum glucose levels, oral glucose tolerance tests or glycosylated hemoglobin values were examined in 19 patients with AIP. N-benzoyl-L-tyrosyl-p-aminobenzoic acid excretion test, sialochemistry and parotid gland scintigraphy were performed in 8 patients. Eight patients had evidence of DM. Steroid therapy subsequently improved insulin secretion and glycemic control in 3 of 5 patients treated. Pancreatic exocrine function was reduced in 88% of patients. Impaired pancreatic exocrine function improved after steroid therapy in 3 of 6 patients treated. The 3 patients also showed treatment-related improvement in endocrine function. Concentration of beta2-microglobulin in saliva was significantly raised in patients with AIP compared with controls (P gland dysfunction improved after steroid therapy in all 5 patients treated. Pancreatic endocrine and exocrine and salivary gland function were frequently impaired in patients with AIP, and steroid therapy was occasionally effective for these dysfunctions.

[Autoimmune pancreatitis. Evidence based management guidelines of the Hungarian Pancreatic Study Group].

Science.gov (United States)

Dubravcsik, Zsolt; Farkas, Gyula; Hegyi, Péter; Hritz, István; Kelemen, Dezső; Lásztity, Natália; Morvay, Zita; Oláh, Attila; Pap, Ákos; Párniczky, Andrea; Sahin-Tóth, Miklós; Szentkereszti, Zsolt; Szmola, Richárd; Takács, Tamás; Tiszlavicz, László; Szücs, Ákos; Czakó, László

2015-02-22

Autoimmune pancreatitis is a rare disease which can even mimic pancreatic tumor, however, unlike the latter, it requires not surgical but conservative management. Correct diagnosis and differential diagnosis of autoimmune pancreatitis and treatment of these patients requires up-to-date and evidence based management guidelines. The Hungarian Pancreatic Study Group proposed to prepare an evidence based guideline based on the available international guidelines and evidences. The preparatory and consultation task force appointed by the Hungarian Pancreatic Study Group translated and complemented and/or modified the international guidelines if it was necessary. 29 relevant clinical questions in 4 topics were defined (Basics; Diagnosis; Differential diagnostics; Therapy). Evidence was classified according to the UpToDate(®) grading system. The draft of the guidelines was presented and discussed at the consensus meeting on September 12, 2014. All clinial questions were accepted with almost total (more than 95%) agreement. The present guideline is the first evidence based autoimmune pancreatitis guideline in Hungary. The guideline may provide very important and helpful data for tuition of autoimmune pancreatitis, for everyday practice and for establishing proper finance. Therefore, the authors believe that these guidelines will widely become a basic reference in Hungary.

The Fas pathway is involved in pancreatic beta cell secretory function

DEFF Research Database (Denmark)

Schumann, Desiree M; Maedler, Kathrin; Franklin, Isobel

2007-01-01

Pancreatic beta cell mass and function increase in conditions of enhanced insulin demand such as obesity. Failure to adapt leads to diabetes. The molecular mechanisms controlling this adaptive process are unclear. Fas is a death receptor involved in beta cell apoptosis or proliferation, depending...... on the activity of the caspase-8 inhibitor FLIP. Here we show that the Fas pathway also regulates beta cell secretory function. We observed impaired glucose tolerance in Fas-deficient mice due to a delayed and decreased insulin secretory pattern. Expression of PDX-1, a beta cell-specific transcription factor...... regulating insulin gene expression and mitochondrial metabolism, was decreased in Fas-deficient beta cells. As a consequence, insulin and ATP production were severely reduced and only partly compensated for by increased beta cell mass. Up-regulation of FLIP enhanced NF-kappaB activity via NF...

The potential role of SOCS-3 in the interleukin-1beta-induced desensitization of insulin signaling in pancreatic beta-cells

DEFF Research Database (Denmark)

Emanuelli, Brice; Glondu, Murielle; Filloux, Chantal

2004-01-01

insulin signaling is required for the optimal beta-cell function, we assessed the effect of IL-1beta on the insulin pathway in a rat pancreatic beta-cell line. We show that IL-1beta decreases insulin-induced tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate (IRS...

Pancreatic Beta-Cell Purification by Altering FAD and NAD(PH Metabolism

Directory of Open Access Journals (Sweden)

P. de Vos

2008-07-01

Full Text Available Isolation of primary beta cells from other cells within in the pancreatic islets is of importance for many fields of islet research. However, up to now, no satisfactory method has been developed that gained high numbers of viable beta cells, without considerable alpha-cell contamination. In this study, we investigated whether rat beta cells can be isolated from nonbeta endocrine cells by manipulating the flavin adenine dinucleotide (FAD and nicotinamide-adenine dinucleotide phosphate (NAD(PH autofluorescence. Beta cells were isolated from dispersed islets by flow cytometry, based on their high FAD and NAD(PH fluorescence. To improve beta cell yield and purity, the cellular FAD and NAD(PH contents were altered by preincubation in culture media containing varying amounts of D-glucose and amino acids. Manipulation of the cellular FAD and NAD(PH fluorescence improves beta cell yield and purity after sorting. This method is also a fast and reliable method to measure beta cell functional viability. A conceivable application is assessing beta cell viability before transplantation.

Growth hormone is a growth factor for the differentiated pancreatic beta-cell

DEFF Research Database (Denmark)

Linde, S; Welinder, B S; Billestrup, N

1989-01-01

The regulation of the growth of the pancreatic beta-cell is poorly understood. There are previous indications of a role of GH in the growth and insulin production of the pancreatic islets. In the present study we present evidence for a direct long-term effect of GH on proliferation and insulin...

Reduced Expression of the Liver/Beta-Cell Glucose Transporter Isoform in Glucose-Insensitive Pancreatic Beta Cells of Diabetic Rats

Science.gov (United States)

Thorens, Bernard; Weir, Gordon C.; Leahy, John L.; Lodish, Harvey F.; Bonner-Weir, Susan

1990-09-01

Rats injected with a single dose of streptozocin at 2 days of age develop non-insulin-dependent diabetes 6 weeks later. The pancreatic beta islet cells of these diabetic rats display a loss of glucose-induced insulin secretion while maintaining sensitivity to other secretagogues such as arginine. We analyzed the level of expression of the liver/beta-cell glucose transporter isoform in diabetic islets by immunofluorescence staining of pancreas sections and by Western blotting of islet lysates. Islets from diabetic animals have a reduced expression of this beta-cell-specific glucose transporter isoform and the extent of reduction is correlated with the severity of hyperglycemia. In contrast, expression of this transporter isoform in liver is minimally modified by the diabetes. Thus a decreased expression of the liver/beta-cell glucose transporter isoform in beta cells is associated with the impaired glucose sensing characteristic of diabetic islets; our data suggest that this glucose transporter may be part of the beta-cell glucose sensor.

Glucose-induced lipogenesis in pancreatic beta-cells is dependent on SREBP-1

DEFF Research Database (Denmark)

Sandberg, Maria B; Fridriksson, Jakob; Madsen, Lise

2005-01-01

High concentrations of glucose induce de novo fatty acid synthesis in pancreatic beta-cells and chronic exposure of elevated glucose and fatty acids synergize to induce accumulation of triglycerides, a phenomenon termed glucolipotoxicity. Here we investigate the role of sterol-regulatory element......, de novo fatty acid synthesis and lipid accumulation are induced primarily through sterol-regulatory elements (SREs) and not E-Boxes. Adenoviral expression of a dominant negative SREBP compromises glucose induction of some lipogenic genes and significantly reduces glucose-induction of de novo fatty...... acid synthesis. Thus, we demonstrate for the first time that SREBP activity is necessary for full glucose induction of de novo fatty acid synthesis in pancreatic beta-cells....

Effect on pancreatic beta cells and nerve cells by low let x-ray

Energy Technology Data Exchange (ETDEWEB)

Park, Kwang Hun [Dept. of Nuclear Medicine, Kyungbuk National University Hospital, Daegu (Korea, Republic of); Kim, Kgu Hwan [Dept. of Radiological Technology, Daegu health College, Daegu (Korea, Republic of)

2014-03-15

Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia condition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

A Case of Pancreatic Cancer in the Setting of Autoimmune Pancreatitis with Nondiagnostic Serum Markers

Directory of Open Access Journals (Sweden)

Manju D. Chandrasegaram

2013-01-01

Full Text Available Background. Autoimmune pancreatitis (AIP often mimics pancreatic cancer. The diagnosis of both conditions is difficult preoperatively let alone when they coexist. Several reports have been published describing pancreatic cancer in the setting of AIP. Case Report. The case of a 53-year-old man who presented with abdominal pain, jaundice, and radiological features of autoimmune pancreatitis, with a “sausage-shaped” pancreas and bulky pancreatic head with portal vein impingement, is presented. He had a normal serum IgG4 and only mildly elevated Ca-19.9. Initial endoscopic ultrasound-(EUS- guided fine-needle aspiration (FNA of the pancreas revealed an inflammatory sclerosing process only. A repeat EUS guided biopsy following biliary decompression demonstrated both malignancy and features of autoimmune pancreatitis. At laparotomy, a uniformly hard, bulky pancreas was found with no sonographically definable mass. A total pancreatectomy with portal vein resection and reconstruction was performed. Histology revealed adenosquamous carcinoma of the pancreatic head and autoimmune pancreatitis and squamous metaplasia in the remaining pancreas. Conclusion. This case highlights the diagnostic and management difficulties in a patient with pancreatic cancer in the setting of serum IgG4-negative, Type 2 AIP.

Type 1 autoimmune pancreatitis.

Science.gov (United States)

Zen, Yoh; Bogdanos, Dimitrios P; Kawa, Shigeyuki

2011-12-07

Before the concept of autoimmune pancreatitis (AIP) was established, this form of pancreatitis had been recognized as lymphoplasmacytic sclerosing pancreatitis or non-alcoholic duct destructive chronic pancreatitis based on unique histological features. With the discovery in 2001 that serum IgG4 concentrations are specifically elevated in AIP patients, this emerging entity has been more widely accepted. Classical cases of AIP are now called type 1 as another distinct subtype (type 2 AIP) has been identified. Type 1 AIP, which accounts for 2% of chronic pancreatitis cases, predominantly affects adult males. Patients usually present with obstructive jaundice due to enlargement of the pancreatic head or thickening of the lower bile duct wall. Pancreatic cancer is the leading differential diagnosis for which serological, imaging, and histological examinations need to be considered. Serologically, an elevated level of IgG4 is the most sensitive and specific finding. Imaging features include irregular narrowing of the pancreatic duct, diffuse or focal enlargement of the pancreas, a peri-pancreatic capsule-like rim, and enhancement at the late phase of contrast-enhanced images. Biopsy or surgical specimens show diffuse lymphoplasmacytic infiltration containing many IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis. A dramatic response to steroid therapy is another characteristic, and serological or radiological effects are normally identified within the first 2 or 3 weeks. Type 1 AIP is estimated as a pancreatic manifestation of systemic IgG4-related disease based on the fact that synchronous or metachronous lesions can develop in multiple organs (e.g. bile duct, salivary/lacrimal glands, retroperitoneum, artery, lung, and kidney) and those lesions are histologically identical irrespective of the organ of origin. Several potential autoantigens have been identified so far. A Th2-dominant immune reaction and the activation of regulatory T-cells are assumed

Type 1 autoimmune pancreatitis

Directory of Open Access Journals (Sweden)

Zen Yoh

2011-12-01

Full Text Available Abstract Before the concept of autoimmune pancreatitis (AIP was established, this form of pancreatitis had been recognized as lymphoplasmacytic sclerosing pancreatitis or non-alcoholic duct destructive chronic pancreatitis based on unique histological features. With the discovery in 2001 that serum IgG4 concentrations are specifically elevated in AIP patients, this emerging entity has been more widely accepted. Classical cases of AIP are now called type 1 as another distinct subtype (type 2 AIP has been identified. Type 1 AIP, which accounts for 2% of chronic pancreatitis cases, predominantly affects adult males. Patients usually present with obstructive jaundice due to enlargement of the pancreatic head or thickening of the lower bile duct wall. Pancreatic cancer is the leading differential diagnosis for which serological, imaging, and histological examinations need to be considered. Serologically, an elevated level of IgG4 is the most sensitive and specific finding. Imaging features include irregular narrowing of the pancreatic duct, diffuse or focal enlargement of the pancreas, a peri-pancreatic capsule-like rim, and enhancement at the late phase of contrast-enhanced images. Biopsy or surgical specimens show diffuse lymphoplasmacytic infiltration containing many IgG4+ plasma cells, storiform fibrosis, and obliterative phlebitis. A dramatic response to steroid therapy is another characteristic, and serological or radiological effects are normally identified within the first 2 or 3 weeks. Type 1 AIP is estimated as a pancreatic manifestation of systemic IgG4-related disease based on the fact that synchronous or metachronous lesions can develop in multiple organs (e.g. bile duct, salivary/lacrimal glands, retroperitoneum, artery, lung, and kidney and those lesions are histologically identical irrespective of the organ of origin. Several potential autoantigens have been identified so far. A Th2-dominant immune reaction and the activation of

Progress in diagnosis and treatment of autoimmune pancreatitis

Directory of Open Access Journals (Sweden)

YIN Tao

2015-05-01

Full Text Available Autoimmune pancreatitis (AIP is a special type of chronic pancreatitis that originates from an autoimmune-mediated mechanism. AIP has unique radiological, serological, and histopathological features, often accompanied by peripancreatic lesions. AIP may be easily confused with pancreatic cancer and cholangiocarcinoma. It is necessary to diagnose AIP while integrating a variety of clinical indicators. Steroid therapy should be performed for patients diagnosed with AIP, and surgical treatment can be selected if necessary.

Pancreatic beta-cell overexpression of the glucagon receptor gene results in enhanced beta-cell function and mass

DEFF Research Database (Denmark)

Gelling, Richard W; Vuguin, Patricia M; Du, Xiu Quan

2009-01-01

in vivo, we generated mice overexpressing the Gcgr specifically on pancreatic beta-cells (RIP-Gcgr). In vivo and in vitro insulin secretion in response to glucagon and glucose was increased 1.7- to 3.9-fold in RIP-Gcgr mice compared with controls. Consistent with the observed increase in insulin release...

Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

Directory of Open Access Journals (Sweden)

Kusmiyati Tjahjono DK

2013-04-01

Full Text Available Background The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. Methods A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. Results After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p=0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. Conclusion TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells.

Trans fatty acids increase nitric oxide levels and pancreatic beta-cell necrosis in rats

Directory of Open Access Journals (Sweden)

Kusmiyati Tjahjono DK

2015-12-01

Full Text Available BACKGROUND The prevalence of diabetes in Indonesia is increasing due to various factors, including life style changes such as trans fatty acid (TFA intake. High TFA intake is known to be related to blood lipid profile changes resulting in cardiovascular disorders. This study was to identify the effect of TFA on nitric oxide (NO production and on necrosis of pancreatic beta cells. METHODS A study of randomized pre-test post–test design with control group. Thirty Sprague Dawley rats were divided into 3 groups, i.e. group K (control, group P1 receiving a diet with 5% TFA, and P2 receiving 10% TFA. The intervention was performed for 8 weeks. NO level and pancreatic beta-cell necrosis were analyzed using Pearson’s chi square test. RESULTS After 4 weeks of treatment there was no change in NO levels in group K, but increased NO in P2 (2.6-3.8 ìM. At 8 weeks after treatment, NO levels in groups P1 and P2 increased to 2.6-3.4 ìM and 4.2-14.3 ìM, respectively, while in group K only 2 rats had increased NO levels of 2.8-2.9 ìM. With Pearson’s chi-square test, there was a signifant difference in the proportions of necrotic pancreatic beta cells after 4 weeks and 8 weeks (p= 0.000. No necrosis of beta cells was found in group K, mild necrosis in group P1 (1-25% and moderate necrosis in group P2 (26-50%. CONCLUSION TFA consumption significantly increases NO levels in Sprague Dawley rats and also results in moderate grades of necrosis of pancreatic beta cells

Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

Directory of Open Access Journals (Sweden)

Cedric Cortijo

2012-12-01

Full Text Available Planar cell polarity (PCP refers to the collective orientation of cells within the epithelial plane. We show that progenitor cells forming the ducts of the embryonic pancreas express PCP proteins and exhibit an active PCP pathway. Planar polarity proteins are acquired at embryonic day 11.5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal that tridimensional organization and collective communication of cells are needed in the pancreatic epithelium in order to generate appropriate numbers of endocrine cells.

Role of growth factors in control of pancreatic beta cell mass: focus on betatrophin.

Science.gov (United States)

Levitsky, Lynne L; Ardestani, Goli; Rhoads, David B

2014-08-01

Betatrophin is a newly described hormone, which potently stimulates beta cell replication in mice. This discovery has engendered great hope that it could prove clinically important in the treatment of type 1 and type 2 diabetes. Betatrophin, a 198-amino acid protein secreted by liver and adipose tissue, stimulates growth of pancreatic beta cell mass in insulin-resistant mice. Betatrophin has previously been named RIFL, lipasin, and ANGPLT8, and its salutory effects on lipid metabolism have been described in mouse and human studies. Serum betatrophin levels in humans correlate with improved adipose tissue lipid storage and lower serum triglyceride levels in the fed state, but do not correlate with insulin resistance or carbohydrate tolerance in humans. Betatrophin has not yet been shown to have an effect on beta cell replication in human pancreatic islets. Many endocrine and paracrine factors, of which betatrophin is the newest described, increase beta cell mass in murine models. None of these factors, including betatrophin, have displayed the same activity in clinical studies. This may reflect a profound species difference in beta cell regeneration pathways in mice and humans.

Expression of transient receptor potential ankyrin 1 (TRPA1 and its role in insulin release from rat pancreatic beta cells.

Directory of Open Access Journals (Sweden)

De-Shou Cao

Full Text Available Several transient receptor potential (TRP channels are expressed in pancreatic beta cells and have been proposed to be involved in insulin secretion. However, the endogenous ligands for these channels are far from clear. Here, we demonstrate the expression of the transient receptor potential ankyrin 1 (TRPA1 ion channel in the pancreatic beta cells and its role in insulin release. TRPA1 is an attractive candidate for inducing insulin release because it is calcium permeable and is activated by molecules that are produced during oxidative glycolysis.Immunohistochemistry, RT-PCR, and Western blot techniques were used to determine the expression of TRPA1 channel. Ca²⁺ fluorescence imaging and electrophysiology (voltage- and current-clamp techniques were used to study the channel properties. TRPA1-mediated insulin release was determined using ELISA.TRPA1 is abundantly expressed in a rat pancreatic beta cell line and freshly isolated rat pancreatic beta cells, but not in pancreatic alpha cells. Activation of TRPA1 by allyl isothiocyanate (AITC, hydrogen peroxide (H₂O₂, 4-hydroxynonenal (4-HNE, and cyclopentenone prostaglandins (PGJ₂ and a novel agonist methylglyoxal (MG induces membrane current, depolarization, and Ca²⁺ influx leading to generation of action potentials in a pancreatic beta cell line and primary cultured pancreatic beta cells. Activation of TRPA1 by agonists stimulates insulin release in pancreatic beta cells that can be inhibited by TRPA1 antagonists such as HC030031 or AP-18 and by RNA interference. TRPA1-mediated insulin release is also observed in conditions of voltage-gated Na⁺ and Ca²⁺ channel blockade as well as ATP sensitive potassium (K(ATP channel activation.We propose that endogenous and exogenous ligands of TRPA1 cause Ca²⁺ influx and induce basal insulin release and that TRPA1-mediated depolarization acts synergistically with K(ATP channel blockade to facilitate insulin release.

Beta-endorphin and the immune system--possible role in autoimmune diseases

DEFF Research Database (Denmark)

Mørch, H; Pedersen, B K

1995-01-01

The immune system and the neuroendocrine system are closely interconnected having such means of bidirectional communication and regulation. In this review, a hypothesis is put forward regarding the possible role of beta-endorphins in the pathogenesis of autoimmune diseases: It is suggested...... that the increased cytokine production in immunoinflammatory disorders induces production of beta-endorphins from the pituitary and the lymphocytes; the enhanced level of beta-endorphin causes inhibition of human T helper cell function, which potentially down-regulate the antibody production. Also the beta......-endorphin-induced enhancement of the natural killer cell activity may suppress the B cell function. In addition, beta-endorphin also exerts a direct inhibitory effect on the antibody production. Thus, in autoimmune disorders the enhanced cytokine level may via stimulation of the production of beta-endorphins exert a negative...

Activation of the transcription factor carbohydrate-responsive element-binding protein by glucose leads to increased pancreatic beta cell differentiation in rats.

Science.gov (United States)

Soggia, A; Flosseau, K; Ravassard, P; Szinnai, G; Scharfmann, R; Guillemain, G

2012-10-01

Pancreatic cell development is a tightly controlled process. Although information is available regarding the mesodermal signals that control pancreatic development, little is known about the role of environmental factors such as nutrients, including glucose, on pancreatic development. We previously showed that glucose and its metabolism through the hexosamine biosynthesis pathway (HBP) promote pancreatic endocrine cell differentiation. Here, we analysed the role of the transcription factor carbohydrate-responsive element-binding protein (ChREBP) in this process. This transcription factor is activated by glucose, and has been recently described as a target of the HBP. We used an in vitro bioassay in which pancreatic endocrine and exocrine cells develop from rat embryonic pancreas in a way that mimics in vivo pancreatic development. Using this model, gain-of-function and loss-of-function experiments were undertaken. ChREBP was produced in the endocrine lineage during pancreatic development, its abundance increasing with differentiation. When rat embryonic pancreases were cultured in the presence of glucose or xylitol, the production of ChREBP targets was induced. Concomitantly, beta cell differentiation was enhanced. On the other hand, when embryonic pancreases were cultured with inhibitors decreasing ChREBP activity or an adenovirus producing a dominant-negative ChREBP, beta cell differentiation was reduced, indicating that ChREBP activity was necessary for proper beta cell differentiation. Interestingly, adenovirus producing a dominant-negative ChREBP also reduced the positive effect of N-acetylglucosamine, a substrate of the HBP acting on beta cell differentiation. Our work supports the idea that glucose, through the transcription factor ChREBP, controls beta cell differentiation from pancreatic progenitors.

Measuring phospholipase D activity in insulin-secreting pancreatic beta-cells and insulin-responsive muscle cells and adipocytes.

Science.gov (United States)

Cazzolli, Rosanna; Huang, Ping; Teng, Shuzhi; Hughes, William E

2009-01-01

Phospholipase D (PLD) is an enzyme producing phosphatidic acid and choline through hydrolysis of phosphatidylcholine. The enzyme has been identified as a member of a variety of signal transduction cascades and as a key regulator of numerous intracellular vesicle trafficking processes. A role for PLD in regulating glucose homeostasis is emerging as the enzyme has recently been identified in events regulating exocytosis of insulin from pancreatic beta-cells and also in insulin-stimulated glucose uptake through controlling GLUT4 vesicle exocytosis in muscle and adipose tissue. We present methodologies for assessing cellular PLD activity in secretagogue-stimulated insulin-secreting pancreatic beta-cells and also insulin-stimulated adipocyte and muscle cells, two of the principal insulin-responsive cell types controlling blood glucose levels.

Enhancing pancreatic Beta-cell regeneration in vivo with pioglitazone and alogliptin.

Directory of Open Access Journals (Sweden)

Hao Yin

Full Text Available Pancreatic beta-cells retain limited ability to regenerate and proliferate after various physiologic triggers. Identifying therapies that are able to enhance beta-cell regeneration may therefore be useful for the treatment of both type 1 and type 2 diabetes.In this study we investigated endogenous and transplanted beta-cell regeneration by serially quantifying changes in bioluminescence from beta-cells from transgenic mice expressing firefly luciferase under the control of the mouse insulin I promoter. We tested the ability of pioglitazone and alogliptin, two drugs developed for the treatment of type 2 diabetes, to enhance beta-cell regeneration, and also defined the effect of the immunosuppression with rapamycin and tacrolimus on transplanted islet beta mass.Pioglitazone is a stimulator of nuclear receptor peroxisome proliferator-activated receptor gamma while alogliptin is a selective dipeptidyl peptidase IV inhibitor. Pioglitazone alone, or in combination with alogliptin, enhanced endogenous beta-cell regeneration in streptozotocin-treated mice, while alogliptin alone had modest effects. In a model of syngeneic islet transplantation, immunosuppression with rapamycin and tacrolimus induced an early loss of beta-cell mass, while treatment with insulin implants to maintain normoglycemia and pioglitazone plus alogliptin was able to partially promote beta-cell mass recovery.These data highlight the utility of bioluminescence for serially quantifying functional beta-cell mass in living mice. They also demonstrate the ability of pioglitazone, used either alone or in combination with alogliptin, to enhance regeneration of endogenous islet beta-cells as well as transplanted islets into recipients treated with rapamycin and tacrolimus.

Autoimmune Pancreatitis.

Science.gov (United States)

Majumder, Shounak; Takahashi, Naoki; Chari, Suresh T

2017-07-01

Autoimmune pancreatitis (AIP) is a chronic fibroinflammatory disease of the pancreas that belongs to the spectrum of immunoglobulin G-subclass4-related diseases (IgG4-RD) and typically presents with obstructive jaundice. Idiopathic duct-centric pancreatitis (IDCP) is a closely related but distinct disease that mimics AIP radiologically but manifests clinically most commonly as recurrent acute pancreatitis in young individuals with concurrent inflammatory bowel disease. IgG4 levels are often elevated in AIP and normal in IDCP. Histologically, lymphoplasmacytic acinar inflammation and storiform fibrosis are seen in both. In addition, the histologic hallmark of IDCP is the granulocyte epithelial lesion: intraluminal and intraepithelial neutrophils in medium-sized and small ducts with or without granulocytic acinar inflammation often associated with destruction of ductal architecture. Initial treatment of both AIP and IDCP is with oral corticosteroids for duration of 4 weeks followed by a gradual taper. Relapses are common in AIP and relatively uncommon in IDCP, a relatively rare disease for which the natural history is not well understood. For patients with relapsing AIP, treatment with immunomodulators and more recently rituximab has been recommended. Although rare instances of pancreaticobiliary malignancy has been reported in patients with AIP, overall the lifetime risk of developing pancreatic cancer does not appear to be elevated.

Restoring Mitochondrial Function: A Small Molecule-mediated Approach to Enhance Glucose Stimulated Insulin Secretion in Cholesterol Accumulated Pancreatic beta cells

Science.gov (United States)

Asalla, Suman; Girada, Shravan Babu; Kuna, Ramya S.; Chowdhury, Debabrata; Kandagatla, Bhaskar; Oruganti, Srinivas; Bhadra, Utpal; Bhadra, Manika Pal; Kalivendi, Shasi Vardhan; Rao, Swetha Pavani; Row, Anupama; Ibrahim, A.; Ghosh, Partha Pratim; Mitra, Prasenjit

2016-06-01

Dyslipidemia, particularly the elevated serum cholesterol levels, aggravate the pathophysiology of type 2 diabetes. In the present study we explored the relationship between fasting blood sugar and serum lipid parameters in human volunteers which revealed a significant linear effect of serum cholesterol on fasting blood glucose. Short term feeding of cholesterol enriched diet to rodent model resulted in elevated serum cholesterol levels, cholesterol accumulation in pancreatic islets and hyperinsulinemia with modest increase in plasma glucose level. To explore the mechanism, we treated cultured BRIN-BD11 pancreatic beta cells with soluble cholesterol. Our data shows that cholesterol treatment of cultured pancreatic beta cells enhances total cellular cholesterol. While one hour cholesterol exposure enhances insulin exocytosis, overnight cholesterol accumulation in cultured pancreatic beta cells affects cellular respiration, and inhibits Glucose stimulated insulin secretion. We further report that (E)-4-Chloro-2-(1-(2-(2,4,6-trichlorophenyl) hydrazono) ethyl) phenol (small molecule M1) prevents the cholesterol mediated blunting of cellular respiration and potentiates Glucose stimulated insulin secretion which was abolished in pancreatic beta cells on cholesterol accumulation.

Autoimmune pancreatitis: case series and review of the literature.

Science.gov (United States)

Shakov, Rada; DePasquale, Joseph R; Elfarra, Hossam; Spira, Robert S

2009-01-01

Autoimmune pancreatitis (AuP) is a chronic pancreatic inflammation secondary to an underlying autoimmune mechanism. After early reports of a particular type of pancreatitis associated with hypergammaglobulinemia, others asserted that there is an autoimmune mechanism involved in some patients with chronic pancreatitis. In 1995 AuP was first described as a distinct clinical entity. Since then, there have been many documented cases of AuP in Japan, and now, perhaps due to increased awareness, more cases are being reported in Europe and the United States. Herein we present our experience with 3 cases of AuP and we review the relevant literature. These 3 cases demonstrate the difficulties that exist in making the diagnosis of AuP and the impact that the diagnosis can have on patient management.

EPConDB: a web resource for gene expression related to pancreatic development, beta-cell function and diabetes.

Science.gov (United States)

Mazzarelli, Joan M; Brestelli, John; Gorski, Regina K; Liu, Junmin; Manduchi, Elisabetta; Pinney, Deborah F; Schug, Jonathan; White, Peter; Kaestner, Klaus H; Stoeckert, Christian J

2007-01-01

EPConDB (http://www.cbil.upenn.edu/EPConDB) is a public web site that supports research in diabetes, pancreatic development and beta-cell function by providing information about genes expressed in cells of the pancreas. EPConDB displays expression profiles for individual genes and information about transcripts, promoter elements and transcription factor binding sites. Gene expression results are obtained from studies examining tissue expression, pancreatic development and growth, differentiation of insulin-producing cells, islet or beta-cell injury, and genetic models of impaired beta-cell function. The expression datasets are derived using different microarray platforms, including the BCBC PancChips and Affymetrix gene expression arrays. Other datasets include semi-quantitative RT-PCR and MPSS expression studies. For selected microarray studies, lists of differentially expressed genes, derived from PaGE analysis, are displayed on the site. EPConDB provides database queries and tools to examine the relationship between a gene, its transcriptional regulation, protein function and expression in pancreatic tissues.

Effect of iron on pancreatic beta cell function and insulin resistance ...

African Journals Online (AJOL)

Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: ...

Autoimmune pancreatitis - the story so far

International Nuclear Information System (INIS)

Jackson, S.

2015-01-01

Full text: Learning objectives: to learn about the main imaging diagnostic findings of AIP and the International Consensus Diagnostic Criteria (ICDC); to understand the best strategies for distinguishing AIP from pancreatic cancer; to emphasise the central role of radiology in the era of “clinical decision making” Autoimmune Pancreatitis (AIP) was first described in 1961 and represents a rare form of immune mediated chronic pancreatitis which is characterised by a marked infiltration of lymphocytes and plasma cells into pancreatic tissue. Whilst the majority of cases present with diffuse gland involvement, approximately 30% of patient’s demonstrate either segmental or focal involvement of the pancreas. Clinical presentation is very variable with patients describing a range of symptoms. Imaging plays a central role in the diagnosis and management of AIP and knowledge of the radiological appearances, which can vary significantly due to the various degrees of fibrosis and inflammatory infiltrate, is critical. Cardinal features include focal or diffuse pancreatic enlargement with the loss of normal lobular architecture. Post contrast enhancement features of the pancreas may also be useful. In addition, pancreatic duct involvement as demonstrated by single or multiple focal strictures with limited more proximal dilatation is common as well as infiltration of the common bile duct.Whilst multimodality appearances may suggest a diagnosis of AIP correlation with clinical history, serology and histopathology is mandatory in order to accurately diagnose atypical cases

Maternal obesity accelerates fetal pancreatic beta-cell but not alpha-cell development in sheep: prenatal consequences.

Science.gov (United States)

Ford, Stephen P; Zhang, Liren; Zhu, Meijun; Miller, Myrna M; Smith, Derek T; Hess, Bret W; Moss, Gary E; Nathanielsz, Peter W; Nijland, Mark J

2009-09-01

Maternal obesity affects offspring weight, body composition, and organ function, increasing diabetes and metabolic syndrome risk. We determined effects of maternal obesity and a high-energy diet on fetal pancreatic development. Sixty days prior to breeding, ewes were assigned to control [100% of National Research Council (NRC) recommendations] or obesogenic (OB; 150% NRC) diets. At 75 days gestation, OB ewes exhibited elevated insulin-to-glucose ratios at rest and during a glucose tolerance test, demonstrating insulin resistance compared with control ewes. In fetal studies, ewes ate their respective diets from 60 days before to 75 days after conception when animals were euthanized under general anesthesia. OB and control ewes increased in body weight by approximately 43% and approximately 6%, respectively, from diet initiation until necropsy. Although all organs were heavier in fetuses from OB ewes, only pancreatic weight increased as a percentage of fetal weight. Blood glucose, insulin, and cortisol were elevated in OB ewes and fetuses on day 75. Insulin-positive cells per unit pancreatic area were 50% greater in fetuses from OB ewes as a result of increased beta-cell mitoses rather than decreased programmed cell death. Lambs of OB ewes were born earlier but weighed the same as control lambs; however, their crown-to-rump length was reduced, and their fat mass was increased. We conclude that increased systemic insulin in fetuses from OB ewes results from increased glucose exposure and/or cortisol-induced accelerated fetal beta-cell maturation and may contribute to premature beta-cell function loss and predisposition to obesity and metabolic disease in offspring.

The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

International Nuclear Information System (INIS)

Woynillowicz, Amanda K.; Raha, Sandeep; Nicholson, Catherine J.; Holloway, Alison C.

2012-01-01

The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

Energy Technology Data Exchange (ETDEWEB)

Woynillowicz, Amanda K. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Raha, Sandeep [Department of Pediatrics, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Holloway, Alison C., E-mail: hollow@mcmaster.ca [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada)

2012-11-15

The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

Regulation of Pancreatic Beta Cell Stimulus-Secretion Coupling by microRNAs

Directory of Open Access Journals (Sweden)

Jonathan L. S. Esguerra

2014-11-01

Full Text Available Increased blood glucose after a meal is countered by the subsequent increased release of the hypoglycemic hormone insulin from the pancreatic beta cells. The cascade of molecular events encompassing the initial sensing and transport of glucose into the beta cell, culminating with the exocytosis of the insulin large dense core granules (LDCVs is termed “stimulus-secretion coupling.” Impairment in any of the relevant processes leads to insufficient insulin release, which contributes to the development of type 2 diabetes (T2D. The fate of the beta cell, when exposed to environmental triggers of the disease, is determined by the possibility to adapt to the new situation by regulation of gene expression. As established factors of post-transcriptional regulation, microRNAs (miRNAs are well-recognized mediators of beta cell plasticity and adaptation. Here, we put focus on the importance of comprehending the transcriptional regulation of miRNAs, and how miRNAs are implicated in stimulus-secretion coupling, specifically those influencing the late stages of insulin secretion. We suggest that efficient beta cell adaptation requires an optimal balance between transcriptional regulation of miRNAs themselves, and miRNA-dependent gene regulation. The increased knowledge of the beta cell transcriptional network inclusive of non-coding RNAs such as miRNAs is essential in identifying novel targets for the treatment of T2D.

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

Energy Technology Data Exchange (ETDEWEB)

Pavlikova, Nela, E-mail: nela.pavlikova@lf3.cuni.cz [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Smetana, Pavel [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic); Halada, Petr [Laboratory of Molecular Structure Characterization, Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague (Czech Republic); Kovar, Jan [Department of Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague (Czech Republic)

2015-10-15

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells

International Nuclear Information System (INIS)

Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

2015-01-01

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. - Highlights: • Epidemiologic studies connect pollution with incidence of diabetes mellitus. • We explored the effect of DDT and DDE on protein expression in the NES2Y pancreatic beta cell line. • One month exposure to three sublethal concentrations of DDT and DDE was employed. • Expression of alpha-enolase, actin

Chronic antidiabetic sulfonylureas in vivo: reversible effects on mouse pancreatic beta-cells.

Directory of Open Access Journals (Sweden)

Maria Sara Remedi

2008-10-01

Full Text Available Pancreatic beta-cell ATP-sensitive potassium (K ATP channels are critical links between nutrient metabolism and insulin secretion. In humans, reduced or absent beta-cell K ATP channel activity resulting from loss-of-function K ATP mutations induces insulin hypersecretion. Mice with reduced K ATP channel activity also demonstrate hyperinsulinism, but mice with complete loss of K ATP channels (K ATP knockout mice show an unexpected insulin undersecretory phenotype. Therefore we have proposed an "inverse U" hypothesis to explain the response to enhanced excitability, in which excessive hyperexcitability drives beta-cells to insulin secretory failure without cell death. Many patients with type 2 diabetes treated with antidiabetic sulfonylureas (which inhibit K ATP activity and thereby enhance insulin secretion show long-term insulin secretory failure, which we further suggest might reflect a similar progression.To test the above hypotheses, and to mechanistically investigate the consequences of prolonged hyperexcitability in vivo, we used a novel approach of implanting mice with slow-release sulfonylurea (glibenclamide pellets, to chronically inhibit beta-cell K ATP channels. Glibenclamide-implanted wild-type mice became progressively and consistently diabetic, with significantly (p < 0.05 reduced insulin secretion in response to glucose. After 1 wk of treatment, these mice were as glucose intolerant as adult K ATP knockout mice, and reduction of secretory capacity in freshly isolated islets from implanted animals was as significant (p < 0.05 as those from K ATP knockout animals. However, secretory capacity was fully restored in islets from sulfonylurea-treated mice within hours of drug washout and in vivo within 1 mo after glibenclamide treatment was terminated. Pancreatic immunostaining showed normal islet size and alpha-/beta-cell distribution within the islet, and TUNEL staining showed no evidence of apoptosis.These results demonstrate that

Inflammatory stress of pancreatic beta cells drives release of extracellular heat-shock protein 90α.

Science.gov (United States)

Ocaña, Gail J; Pérez, Liliana; Guindon, Lynette; Deffit, Sarah N; Evans-Molina, Carmella; Thurmond, Debbie C; Blum, Janice S

2017-06-01

A major obstacle in predicting and preventing the development of autoimmune type 1 diabetes (T1D) in at-risk individuals is the lack of well-established early biomarkers indicative of ongoing beta cell stress during the pre-clinical phase of disease. Recently, serum levels of the α cytoplasmic isoform of heat-shock protein 90 (hsp90) were shown to be elevated in individuals with new-onset T1D. We therefore hypothesized that hsp90α could be released from beta cells in response to cellular stress and inflammation associated with the earliest stages of T1D. Here, human beta cell lines and cadaveric islets released hsp90α in response to stress induced by treatment with a combination of pro-inflammatory cytokines including interleukin-1β, tumour necrosis factor-α and interferon-γ. Mechanistically, hsp90α release was found to be driven by cytokine-induced endoplasmic reticulum stress mediated by c-Jun N-terminal kinase (JNK), a pathway that can eventually lead to beta cell apoptosis. Cytokine-induced beta cell hsp90α release and JNK activation were significantly reduced by pre-treating cells with the endoplasmic reticulum stress-mitigating chemical chaperone tauroursodeoxycholic acid. The hsp90α release by cells may therefore be a sensitive indicator of stress during inflammation and a useful tool in assessing therapeutic mitigation of cytokine-induced cell damage linked to autoimmunity. © 2017 John Wiley & Sons Ltd.

The zinc transporter ZNT3 co-localizes with insulin in INS-1E pancreatic beta cells and influences cell survival, insulin secretion capacity, and ZNT8 expression

DEFF Research Database (Denmark)

Smidt, Kamille; Larsen, Agnete; Brønden, Andreas

2016-01-01

Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage in the granu......Zinc trafficking in pancreatic beta cells is tightly regulated by zinc transporting (ZNTs) proteins. The role of different ZNTs in the beta cells is currently being clarified. ZNT8 transports zinc into insulin granules and is critical for a correct insulin crystallization and storage...

Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

Science.gov (United States)

Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

2015-10-01

Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

Drp1 guarding of the mitochondrial network is important for glucose-stimulated insulin secretion in pancreatic beta cells

Energy Technology Data Exchange (ETDEWEB)

Reinhardt, Florian; Schultz, Julia; Waterstradt, Rica; Baltrusch, Simone, E-mail: simone.baltrusch@med.uni-rostock.de

2016-06-10

Mitochondria form a tubular network in mammalian cells, and the mitochondrial life cycle is determined by fission, fusion and autophagy. Dynamin-related protein 1 (Drp1) has a pivotal role in these processes because it alone is able to constrict mitochondria. However, the regulation and function of Drp1 have been shown to vary between cell types. Mitochondrial morphology affects mitochondrial metabolism and function. In pancreatic beta cells mitochondrial metabolism is a key component of the glucose-induced cascade of insulin secretion. The goal of the present study was to investigate the action of Drp1 in pancreatic beta cells. For this purpose Drp1 was down-regulated by means of shDrp1 in insulin-secreting INS1 cells and mouse pancreatic islets. In INS1 cells reduced Drp1 expression resulted in diminished expression of proteins regulating mitochondrial fusion, namely mitofusin 1 and 2, and optic atrophy protein 1. Diminished mitochondrial dynamics can therefore be assumed. After down-regulation of Drp1 in INS1 cells and spread mouse islets the initially homogenous mitochondrial network characterised by a moderate level of interconnections shifted towards high heterogeneity with elongated, clustered and looped mitochondria. These morphological changes were found to correlate directly with functional alterations. Mitochondrial membrane potential and ATP generation were significantly reduced in INS1 cells after Drp1down-regulation. Finally, a significant loss of glucose-stimulated insulin secretion was demonstrated in INS1 cells and mouse pancreatic islets. In conclusion, Drp1 expression is important in pancreatic beta cells to maintain the regulation of insulin secretion. -- Highlights: •Down-regulation of Drp1 in INS1 cells reduces mitochondrial fusion protein expression. •Mitochondrial membrane potential in INS1 cells is diminished after Drp1 down-regulation. •Mitochondria become elongated after down-regulation of Drp1 in beta cells. •Down-regulation of

Do immunotherapy and beta cell replacement play a synergistic role in the treatment of type 1 diabetes?

Science.gov (United States)

Li, Dong-Sheng; Warnock, Garth L; Tu, Han-Jun; Ao, Ziliang; He, Zehua; Lu, Hong; Dai, Long-Jun

2009-10-07

Type 1 diabetes (T1D) is the result of the autoimmune response against pancreatic insulin-producing ss-cells. Its ultimate consequence is beta-cell insufficiency-mediated dysregulation of blood glucose control. In terms of T1D treatment, immunotherapy addresses the cause of T1D, mainly through re-setting the balance between autoimmunity and regulatory mechanisms. Regulatory T cells play an important role in this immune intervention. An alternative T1D treatment is beta-cell replacement, which can reverse the consequence of the disease by replacing destroyed beta-cells in the diabetic pancreas. The applicable insulin-producing cells can be directly obtained from islet transplantation or generated from other cell sources such as autologous adult stem cells, embryonic stem cells, and induced pluripotent stem cells. In this review, we summarize the recent research progress and analyze the possible advantages and disadvantages of these two therapeutic options especially focusing on the potential synergistic effect on T1D treatment. Exploring the optimal combination of immunotherapy and beta-cell replacement will pave the way to the most effective cure for this devastating disease.

Abdominal ultrasonogram of autoimmune pancreatitis: Five cases of pancreatic lesions accompanied by Sjögren syndrome.

Science.gov (United States)

Yoshizaki, Hideo; Takeuchi, Kazuo; Okuda, Chikao; Honjyo, Hajime; Yamamoto, Takatugu; Kora, Tetuo; Takamori, Yoriyuki

2002-09-01

The concept of autoimmune pancreatitis has recently been established, and ultrasonographic findings we obtained from five cases consistent with autoimmune pancreatitis are reported here. Case 1, a 77-year-old man, was admitted complaining of loss of body weight. Serum hepatobiliary enzymes and γ-globulin levels were elevated, and antinuclear antibody was positive, Abdominal ultrasonography showed dilatation of the intrahepatic bile duct, wall thickening of the common bile duct and hypoechoic swelling of the pancreatic head and body. ERCP revealed multiple stenosis of the intra-and extra-hepatic bile ducts, and diffuse irregular narrowing of the main pancreatic duct. The patient complained of thirst, and the minor salivary gland was examined histologically. Our diagnosis was Sjögren syndrome accompanied by sclerosing cholangitis and a pancreatic lesion. Obstructive jaundice also developed, and PTCD was therefore performed. Both the pancreatic swelling and multiple stenosis of the bile duct improved after steroids were administered. Case 2, a 71-year-old man, was admitted with jaundice. Abdominal ultrasonography showed hypoechoic swelling of the pancreas. ERCP showed stenosis of the common bile duct in the pancreatic head region and diffuse irregular narrowing of the main pancreatic duct. Histological examination of the minor salivary gland suggested Sjögren syndrome. Steroids were therefore administered because the presence of both hyper-γ-globulinemia and positive antinuclear antibody suggested involvement of the autoimmune mechanism. Steroid therapy improved the jaundice as well as the findings from the cholangiograms and pancreatograms. We also encountered three similar cases, all consistent with the concept of autoimmune pancreatitis. The ultrasonographic findings of the pancreatic lesion (1) showed them as homogeneous and markedly hypoechoic areas and, (2) visualized the main pancreatic duct in the lesion, which facilitated a differential diagnosis of the

Do we really need to differentiate mesenchymal stem cells into insulin-producing cells for attenuation of the autoimmune responses in type 1 diabetes: immunoprophylactic effects of precursors to insulin-producing cells.

Science.gov (United States)

Sharma, Anshu; Rani, Rajni

2017-07-12

Type 1 diabetes (T1D) is a multifactorial autoimmune disorder where pancreatic beta cells are lost before the clinical manifestations of the disease. Administration of mesenchymal stem cells (MSCs) or MSCs differentiated into insulin-producing cells (IPCs) have yielded limited success when used therapeutically. We have evaluated the immunoprophylactic potentials of precursors to insulin-producing cells (pIPCs) and IPCs in nonobese diabetic (NOD) mice to ask a basic question: do we need to differentiate MSCs into IPCs or will pIPCs suffice to attenuate autoimmune responses in T1D? Bone marrow-derived MSCs from Balb/c mice were characterized following the International Society for Cellular Therapy (ISCT) guidelines. MSCs cultured in high-glucose media for 11 to 13 passages were characterized for the expression of pancreatic lineage genes using real-time polymerase chain reaction. Expression of the PDX1 gene in pIPCs was assessed using Western blot and fluorescence-activated cell sorting (FACS). Triple-positive MSCs were differentiated into IPCs using a three-step protocol after sorting them for cell surface markers, i.e. CD29, CD44, and SCA-1. Nonobese diabetic mice were administered pIPCs, IPCs, or phosphate-buffered saline (PBS) into the tail vein at weeks 9 or 10 and followed-up for 29-30 weeks for fasting blood glucose levels. Two consecutive blood sugar levels of more than 250 mg/dl were considered diabetic. MSCs grown in high-glucose media for 11 to 13 passages expressed genes of the pancreatic lineage such as PDX1, beta2, neurogenin, PAX4, Insulin, and glucagon. Furthermore, Western blot and FACS analysis for PDX-1, a transcription factor necessary for beta cell maturation, confirmed that these cells were precursors of insulin-producing cells (pIPCs). NOD mice administered with pIPCs were better protected from developing diabetes with a protective efficacy of 78.4% (p cells seem to have better potential to arrest autoimmune response in type 1 diabetes when

Intracellular serotonin modulates insulin secretion from pancreatic beta-cells by protein serotonylation.

Directory of Open Access Journals (Sweden)

Nils Paulmann

2009-10-01

Full Text Available While serotonin (5-HT co-localization with insulin in granules of pancreatic beta-cells was demonstrated more than three decades ago, its physiological role in the etiology of diabetes is still unclear. We combined biochemical and electrophysiological analyses of mice selectively deficient in peripheral tryptophan hydroxylase (Tph1-/- and 5-HT to show that intracellular 5-HT regulates insulin secretion. We found that these mice are diabetic and have an impaired insulin secretion due to the lack of 5-HT in the pancreas. The pharmacological restoration of peripheral 5-HT levels rescued the impaired insulin secretion in vivo. These findings were further evidenced by patch clamp experiments with isolated Tph1-/- beta-cells, which clearly showed that the secretory defect is downstream of Ca(2+-signaling and can be rescued by direct intracellular application of 5-HT via the clamp pipette. In elucidating the underlying mechanism further, we demonstrate the covalent coupling of 5-HT by transglutaminases during insulin exocytosis to two key players in insulin secretion, the small GTPases Rab3a and Rab27a. This renders them constitutively active in a receptor-independent signaling mechanism we have recently termed serotonylation. Concordantly, an inhibition of such activating serotonylation in beta-cells abates insulin secretion. We also observed inactivation of serotonylated Rab3a by enhanced proteasomal degradation, which is in line with the inactivation of other serotonylated GTPases. Our results demonstrate that 5-HT regulates insulin secretion by serotonylation of GTPases within pancreatic beta-cells and suggest that intracellular 5-HT functions in various microenvironments via this mechanism in concert with the known receptor-mediated signaling.

[Factors causing damage and destruction of beta-cells of the islets of Langerhans in the pancreas].

Science.gov (United States)

Anděl, Michal; Němcová, Vlasta; Pavlíková, Nela; Urbanová, Jana; Cecháková, Marie; Havlová, Andrea; Straková, Radka; Večeřová, Livia; Mandys, Václav; Kovář, Jan; Heneberg, Petr; Trnka, Jan; Polák, Jan

2014-09-01

Insulin secretion in patients with manifested diabetes mellitus tends to disappear months to decades after the diagnosis, which is a clear sign of a gradual loss of pancreatic islet beta-cells. In our sample of 30 type 2 diabetic patients, whose disease manifested between 30 and 45 years of age, about a half have retained or even increased insulin secretion 30 years later, while the other half exhibit a much diminished or lost insulin secretion. Factors that can damage or destroy beta-cells can be divided into the following groups: Metabolic factors: hyperglycemia and glucotoxicity, lipotoxicity, hypoxia, reactive oxygen species; Pharmacological factors: antimicrobial medication pentamidine, SSRI antidepressants; Factors related to impaired insulin secretion: MODY type diabetes; Environmental toxic factors: rat poison Vacor, streptozotocin, polychlorinated and polybrominated hydrocarbons; Disorders of the exocrine pancreas: tumor infiltration, fibrous infiltration, chronic pancreatitis, cystic fibrosis; Infections, inflammation, autoimmunity, viral factors: Coxsackie viruses, H1N1 influenza, enteroviruses. We are currently working on finding other factors leading to beta-cell damage, studying their effect on apoptosis and necrosis and looking for possible protective factors to prevent this damage. We our increasing knowledge about the mechanisms of beta-cell damage and destruction we come ever closer to suggest measures for their prevention. In this review we offer a brief and simplified summary of some of the findings related to this area.Key words: pancreatic islet beta-cells of Langerhans - factors damaging or destroying beta-cells - insulin secretion.

Review Article: Diagnosis and Management of Igg4 Autoimmune Pancreatitis

OpenAIRE

Ahmed Salem; Diaa Hamouda; Alyssa Parian

2015-01-01

Autoimmune pancreatitis (AIP) is a rare form of chronic pancreatitis that has only recently been recognized as a separate type of pancreatitis in the last two decades. The histopathological features of this distinct form of pancreatitis was first described as early as 1961 when the French Henry Sarles.

Activation of the Wnt/β-catenin pathway in pancreatic beta cells during the compensatory islet hyperplasia in prediabetic mice

International Nuclear Information System (INIS)

Maschio, D.A.; Oliveira, R.B.; Santos, M.R.; Carvalho, C.P.F.; Barbosa-Sampaio, H.C.L.; Collares-Buzato, C.B.

2016-01-01

The Wnt/β-catenin signaling pathway, also known as the canonical Wnt pathway, plays a role in cell proliferation and differentiation in several tissues/organs. It has been recently described in humans a relationship between type 2 diabetes (T2DM) and mutation in the gene encoding the transcription factor TCF7L2 associated to the Wnt/β-catenin pathway. In the present study, we demonstrated that hyperplastic pancreatic islets from prediabetic mice fed a high-fat diet (HFD) for 60 d displayed nuclear translocation of active β-catenin associated with significant increases in protein content and gene expression of β-catenin as well as of cyclins D1, D2 and c-Myc (target genes of the Wnt pathway) but not of Tcf7l2 (the transcription factor). Meanwhile, these alterations were not observed in pancreatic islets from 30 d HFD-fed mice, that do not display significant beta cell hyperplasia. These data suggest that the Wnt/β-catenin pathway is activated in pancreatic islets during prediabetes and may play a role in the induction of the compensatory beta cell hyperplasia observed at early phase of T2DM. - Highlights: • Exposure to high-fat diet for 60 days induced prediabetes and beta cell mass expansion. • Hyperplastic pancreatic islets displayed nuclear translocation of active β-catenin. • Hyperplastic islets showed increased expression of target genes of the Wnt/β-catenin pathway. • Wnt/β-catenin pathway is activated during compensatory beta cell hyperplasia in mice.

PARP-1 and YY1 are important novel regulators of CXCL12 gene transcription in rat pancreatic beta cells.

Directory of Open Access Journals (Sweden)

Jelena Marković

Full Text Available Despite significant progress, the molecular mechanisms responsible for pancreatic beta cell depletion and development of diabetes remain poorly defined. At present, there is no preventive measure against diabetes. The positive impact of CXCL12 expression on the pancreatic beta cell prosurvival phenotype initiated this study. Our aim was to provide novel insight into the regulation of rat CXCL12 gene (Cxcl12 transcription. The roles of poly(ADP-ribose polymerase-1 (PARP-1 and transcription factor Yin Yang 1 (YY1 in Cxcl12 transcription were studied by examining their in vitro and in vivo binding affinities for the Cxcl12 promoter in a pancreatic beta cell line by the electrophoretic mobility shift assay and chromatin immunoprecipitation. The regulatory activities of PARP-1 and YY1 were assessed in transfection experiments using a reporter vector with a Cxcl12 promoter sequence driving luciferase gene expression. Experimental evidence for PARP-1 and YY1 revealed their trans-acting potential, wherein PARP-1 displayed an inhibitory, and YY1 a strong activating effect on Cxcl12 transcription. Streptozotocin (STZ-induced general toxicity in pancreatic beta cells was followed by changes in Cxcl12 promoter regulation. PARP-1 binding to the Cxcl12 promoter during basal and in STZ-compromised conditions led us to conclude that PARP-1 regulates constitutive Cxcl12 expression. During the early stage of oxidative stress, YY1 exhibited less affinity toward the Cxcl12 promoter while PARP-1 displayed strong binding. These interactions were accompanied by Cxcl12 downregulation. In the later stages of oxidative stress and intensive pancreatic beta cell injury, YY1 was highly expressed and firmly bound to Cxcl12 promoter in contrast to PARP-1. These interactions resulted in higher Cxcl12 expression. The observed ability of PARP-1 to downregulate, and of YY1 to upregulate Cxcl12 promoter activity anticipates corresponding effects in the natural context where the

Nuclear import of glucokinase in pancreatic beta-cells is mediated by a nuclear localization signal and modulated by SUMOylation.

Science.gov (United States)

Johansson, Bente Berg; Fjeld, Karianne; Solheim, Marie Holm; Shirakawa, Jun; Zhang, Enming; Keindl, Magdalena; Hu, Jiang; Lindqvist, Andreas; Døskeland, Anne; Mellgren, Gunnar; Flatmark, Torgeir; Njølstad, Pål Rasmus; Kulkarni, Rohit N; Wierup, Nils; Aukrust, Ingvild; Bjørkhaug, Lise

2017-10-15

The localization of glucokinase in pancreatic beta-cell nuclei is a controversial issue. Although previous reports suggest such a localization, the mechanism for its import has so far not been identified. Using immunofluorescence, subcellular fractionation and mass spectrometry, we present evidence in support of glucokinase localization in beta-cell nuclei of human and mouse pancreatic sections, as well as in human and mouse isolated islets, and murine MIN6 cells. We have identified a conserved, seven-residue nuclear localization signal ( 30 LKKVMRR 36 ) in the human enzyme. Substituting the residues KK 31,32 and RR 35,36 with AA led to a loss of its nuclear localization in transfected cells. Furthermore, our data indicates that SUMOylation of glucokinase modulates its nuclear import, while high glucose concentrations do not significantly alter the enzyme nuclear/cytosolic ratio. Thus, for the first time, we provide data in support of a nuclear import of glucokinase mediated by a redundant mechanism, involving a nuclear localization signal, and which is modulated by its SUMOylation. These findings add new knowledge to the functional role of glucokinase in the pancreatic beta-cell. Copyright © 2017 Elsevier B.V. All rights reserved.

Fifteen-Year-Old Male with Type 2 Autoimmune Pancreatitis: An Argument for Endoscopy

Directory of Open Access Journals (Sweden)

Nathan T. Kolasinski

2017-05-01

Full Text Available Type 2 autoimmune pancreatitis, an increasingly recognized etiology of pancreatitis in patients less than 20 years old, has characteristically been diagnosed with the histological finding of duct-centric pancreatitis in a patient who lacks elevated serum immunoglobulin G4. We present the case of a nonobese 15-year-old male, without any chronic medical conditions, who presented with the chief complaint of abdominal pain. The laboratory study results were remarkable for a lipase level of 5,419 U/L and a γ-glutamyl transferase level of 373 U/L. Magnetic resonance cholangiopancreatography revealed delayed contrast enhancement of the pancreas, diffuse parenchymal enlargement, and lack of normal lobulation. The patient’s serum immunoglobulin G4 level was found to be 66 mg/dL, which was within normal limits and supportive of a diagnosis of type 2 autoimmune pancreatitis. Despite the absence of intestinal complaints, the patient underwent subsequent endoscopy due to the correlation of type 2 autoimmune pancreatitis with inflammatory bowel disease that has been described in recent literature. Pan-colonic mild colitis was visualized, and the patient began treatment with steroids, to which he quickly responded. Performing endoscopy on this patient allowed for confident initiation of early therapy for both autoimmune pancreatitis and inflammatory bowel disease, and may have limited further surgical intervention and disease progression. For these reasons, this case highlights the utility of endoscopy in pediatric patients with suspected type 2 autoimmune pancreatitis, even in the absence of intestinal symptoms.

Islet-selectivity of G-protein coupled receptor ligands evaluated for PET imaging of pancreatic {beta}-cell mass

Energy Technology Data Exchange (ETDEWEB)

Cline, Gary W., E-mail: gary.cline@yale.edu [Yale University School of Medicine (United States); Zhao, Xiaojian [Yale University School of Medicine (United States); Jakowski, Amy B.; Soeller, Walter C.; Treadway, Judith L. [Pfizer Global Research and Development, Pfizer Inc., Groton CT (United States)

2011-09-02

Highlights: {yields} We screened G-protein coupled receptors for imaging pancreatic. {yields} Database mining and immunohistochemistry identified GPCRs enriched in {beta}-cells. {yields} In vitro and in vivo assays were used to determine exocrine vs endocrine specificity. {yields} GPCR candidates for imaging of {beta}-cell mass are Prokineticin-1R, mGluR5, and GLP-1R. -- Abstract: A critical unmet need exists for methods to quantitatively measure endogenous pancreatic {beta}-cell mass (BCM) for the clinical evaluation of therapies to prevent or reverse loss of BCM and diabetes progression. Our objective was to identify G-protein coupled receptors (GPCRs) that are expressed with a high degree of specificity to islet {beta}-cells for receptor-targeted imaging of BCM. GPCRs enriched in pancreatic islets relative to pancreas acinar and hepatic tissue were identified using a database screen. Islet-specific expression was confirmed by human pancreas immunohistochemistry (IHC). In vitro selectivity assessment was determined from the binding and uptake of radiolabeled ligands to the rat insulinoma INS-1 832/13 cell line and isolated rat islets relative to the exocrine pancreas cell-type, PANC-1. Tail-vein injections of radioligands into rats were used to determine favorable image criteria of in vivo biodistribution to the pancreas relative to other internal organs (i.e., liver, spleen, stomach, and lungs). Database and IHC screening identified four candidate receptors for further in vitro and in vivo evaluation for PET imaging of BCM: prokineticin-1 receptor (PK-1R), metabotropic glutamate receptor type-5 (mGluR5), neuropeptide Y-2 receptor (NPY-2R), and glucagon-like peptide 1 receptor (GLP-1R). In vitro specificity ratios gave the following receptor rank order: PK-1R > GLP-1R > NPY-2R > mGluR5. The biodistribution rank order of selectivity to the pancreas was found to be PK-1R > VMAT2 {approx} GLP-1R > mGluR5. Favorable islet selectivity and biodistribution

The long-term impact of autoimmune pancreatitis on pancreatic function, quality of life, and life expectancy

NARCIS (Netherlands)

Buijs, Jorie; Cahen, Djuna L.; Van Heerde, Marianne J.; Rauws, Erik A.; De Buy Wenniger, Lucas J Maillette; Hansen, Bettina E.; Biermann, Katharina; Verheij, Joanne; Vleggaar, FP; Brink, Menno A.; Beuers, Ulrich H W; Van Buuren, Henk R.; Bruno, Marco J.

2015-01-01

Objective: To evaluate the long-termoutcome of autoimmune pancreatitis. Methods: Patients with at least 2 years of follow-up were included. Information was collected regarding disease characteristics, treatment outcome, diagnosedmalignancies, andmortality. In addition, pancreatic function and

Autoimmune pancreatitis in Japan: overview and perspective.

Science.gov (United States)

Shimosegawa, Tooru; Kanno, Atsushi

2009-01-01

Since the rediscovery and definition of autoimmune pancreatitis (AIP) by Yoshida et al. in 1995, the disease has been attracting attention because of its unique clinical features and practical issues. This disease shows very impressive imaging findings, serological changes, and characteristic histopathology. It occurs most commonly in elderly males with painless jaundice or mild abdominal pain; resemblance in imaging findings between AIP and pancreatobiliary cancers poses an important practical issue of differentiation. With increasing recognition of AIP and accumulation of cases, another important feature of this disease has been revealed, i.e., association of extrapancreatic organ involvements. Initially misunderstood because it can be accompanied by other autoimmune disorders, such as Sjögren's syndrome or primary sclerosing cholangitis (PSC), AIP is now known to be associated with unique types of sialadenitis and cholangitis distinct from Sjögren's syndrome or PSC. Now the concept of "IgG4-related sclerosing disease" has become widely accepted and the list of organs involved continues to increase. With worldwide recognition, an emerging issue is the clinical definition of other possible types of autoimmune-related pancreatitis called "idiopathic duct-centric chronic pancreatitis (IDCP)" and "AIP with granulocyte epithelial lesion (GEL)" and their relation to AIP with lymphoplasmacytic sclerosing pancreatitis (LPSP). The time has arrived to establish clinical diagnostic criteria of AIP based on international consensus and to discuss regional and racial differences in the clinicopathological features of AIP. Consensus guidelines are also required for the ideal use of steroids in the treatment of AIP to suppress recurrence efficiently with minimal side effects. There are many issues to be settled in AIP; international collaboration of experts in the pancreas field is necessary to clarify the entire picture of this unique and important disease.

Autoimmune pancreatitis in Japan. Overview and perspective

International Nuclear Information System (INIS)

Shimosegawa, Tooru; Kanno, Atsushi

2009-01-01

Since the rediscovery and definition of autoimmune pancreatitis (AIP) by Yoshida et al. in 1995, the disease has been attracting attention because of its unique clinical features and practical issues. This disease shows very impressive imaging findings, serological changes, and characteristic histopathology. It occurs most commonly in elderly males with painless jaundice or mild abdominal pain; resemblance in imaging findings between AIP and pancreatobiliary cancers poses an important practical issue of differentiation. With increasing recognition of AIP and accumulation of cases, another important feature of this disease has been revealed, id est (i.e.), association of extrapancreatic organ involvements. Initially misunderstood because it can be accompanied by other autoimmune disorders, such as Sjogren's syndrome or primary sclerosing cholangitis (PSC), AIP is now known to be associated with unique types of sialadenitis and cholangitis distinct from Sjogren's syndrome or PSC. Now the concept of 'IgG4-related sclerosing disease' has become widely accepted and the list of organs involved continues to increase. With worldwide recognition, an emerging issue is the clinical definition of other possible types of autoimmune-related pancreatitis called 'idiopathic duct-centric chronic pancreatitis (IDCP)' and AIP with granulocyte epithelial lesion (GEL)' and their relation to AIP with lymphoplasmacytic sclerosing pancreatitis (LPSP). The time has arrived to establish clinical diagnostic criteria of AIP based on international consensus and to discuss regional and racial differences in the clinicopathological features of AIP. Consensus guidelines are also required for the ideal use of steroids in the treatment of AIP to suppress recurrence efficiently with minimal side effects. There are many issues to be settled in AIP; international collaboration of experts in the pancreas field is necessary to clarify the entire picture of this unique and important disease. (author)

Development of biomarker specific of pancreatic beta cells (incretin radiolabelled) for image of beta functional mass in diabetic and obese: study in animal model

International Nuclear Information System (INIS)

Seo, Daniele

2017-01-01

Increased prevalence of obesity worldwide, has become a vast concern, stimulating investigations focusing prevention and therapy of this condition. The association of type 2 diabetes or insulin resistance aggravates the prognosis of obesity. Even patients successfully submitted to bariatric or metabolic surgery, may not be cured of diabetes, as improvement of circulating values of glucose and insulin not necessarily reflects recovery of pancreatic beta cell mass. There is no consensus about how to estimate beta cell mass in vivo. Available tools suffer from low sensitivity and specificity, often being as well cumbersome and expensive. Radiolabeled incretins, such as glucagon-like-peptide 1 (GLP-1) analogs, seem to be promising options for the measurement of beta cell mass in diabetes and insulinoma. The objective of this study was the development of two conjugates of GLP-1 analog, radiolabeled with 99m Technetium, as a noninvasive imaging method for the estimation of pancreatic beta cell mass, in the presence of obesity. Animal models were selected, including hyperlipidic diet-induced obesity, diet restricted obesity, and as controls, alloxan diabetes. Results indicated that both radiotracers achieved over 97% radiochemical yield. The most successful product was 99m Tc-HYNIC-βAla-Exendin-4. Low beta cell mass uptake occurred in diet-induced obesity. Diet-restricted obesity, with substantial shedding of excess body weight, was followed by remarkable decrease of fasting blood glucose, however beta cell mass uptake was only mildly improved. Future studies are recommended in obesity, type 2 diabetes, and dieting, including bariatric and metabolic operations. (author)

Increased androgen levels in rats impair glucose-stimulated insulin secretion through disruption of pancreatic beta cell mitochondrial function.

Science.gov (United States)

Wang, Hongdong; Wang, Xiaping; Zhu, Yunxia; Chen, Fang; Sun, Yujie; Han, Xiao

2015-11-01

Although insulin resistance is recognized to contribute to the reproductive and metabolic phenotypes of polycystic ovary syndrome (PCOS), pancreatic beta cell dysfunction plays an essential role in the progression from PCOS to the development of type 2 diabetes. However, the role of insulin secretory abnormalities in PCOS has received little attention. In addition, the precise changes in beta cells and the underlying mechanisms remain unclear. In this study, we therefore attempted to elucidate potential mechanisms involved in beta cell alterations in a rat model of PCOS. Glucose-induced insulin secretion was measured in islets isolated from DHT-treated and control rats. Oxygen consumption rate (OCR), ATP production, and mitochondrial copy number were assayed to evaluate mitochondrial function. Glucose-stimulated insulin secretion is significantly decreased in islets from DHT-treated rats. On the other hand, significant reductions are observed in the expression levels of several key genes involved in mitochondrial biogenesis and in mitochondrial OCR and ATP production in DHT-treated rat islets. Meanwhile, we found that androgens can directly impair beta cell function by inducing mitochondrial dysfunction in vitro in an androgen receptor dependent manner. For the first time, our study demonstrates that increased androgens in female rats can impair glucose-stimulated insulin secretion partly through disruption of pancreatic beta cell mitochondrial function. This work has significance for hyperandrogenic women with PCOS: excess activation of the androgen receptor by androgens may provoke beta cell dysfunction via mitochondrial dysfunction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

DEFF Research Database (Denmark)

Martens, Geert A; Jiang, Lei; Hellemans, Karine H

2011-01-01

The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

The Long-Term Impact of Autoimmune Pancreatitis on Pancreatic Function, Quality of Life, and Life Expectancy

NARCIS (Netherlands)

J. Buijs (Jan); D.L. Cahen (Djuna); M. van Heerde (Marianne); Rauws, EA; L.J.M. De Buy Wenniger (Lucas J. Maillette); B.E. Hansen (Bettina); K. Biermann (Katharina); J. Verheij (Joanne); F.P. Vleggaar (Frank); M.A. Brink (Menno); U. Beuers (Ulrich); H.R. van Buuren (Henk); M.J. Bruno (Marco)

2015-01-01

textabstractObjective To evaluate the long-term outcome of autoimmune pancreatitis. Methods Patients with at least 2 years of follow-up were included. Information was collected regarding disease characteristics, treatment outcome, diagnosed malignancies, and mortality. In addition, pancreatic

Vanadyl Sulfate Treatment Stimulates Proliferation and Regeneration of Beta Cells in Pancreatic Islets

Directory of Open Access Journals (Sweden)

Samira Missaoui

2014-01-01

Full Text Available We examined the effects of vanadium sulfate (VOSO4 treatment at 5 and 10 mg/kg for 30 days on endocrine pancreas activity and histology in nondiabetic and STZ-induced diabetic rats. In diabetic group, blood glucose levels significantly increased while insulinemia level markedly decreased. At the end of treatment, VOSO4 at a dose of 10 mg/Kg normalized blood glucose level in diabetic group, restored insulinemia, and significantly improved insulin sensitivity. VOSO4 also increased in a dose-dependent manner the number of insulin immunopositive beta cells in pancreatic islets of nondiabetic rats. Furthermore, in the STZ-diabetic group, the decrease in the number of insulin immunopositive beta cells was corrected to reach the control level mainly with the higher dose of vanadium. Therefore, VOSO4 treatment normalized plasma glucose and insulin levels and improved insulin sensitivity in STZ-experimental diabetes and induced beta cells proliferation and/or regeneration in normal or diabetic rats.

Activation of transmembrane bile acid receptor TGR5 stimulates insulin secretion in pancreatic {beta} cells

Energy Technology Data Exchange (ETDEWEB)

Kumar, Divya P.; Rajagopal, Senthilkumar; Mahavadi, Sunila [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Mirshahi, Faridoddin [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Grider, John R. [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Murthy, Karnam S., E-mail: skarnam@vcu.edu [Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA (United States); Sanyal, Arun J., E-mail: asanyal@mcvh-vcu.edu [Division of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA (United States)

2012-10-26

Highlights: Black-Right-Pointing-Pointer G protein coupled receptor TGR5 is expressed in mouse and human islets. Black-Right-Pointing-Pointer TGR5 is coupled to activation of Gs and Ca{sup 2+} release via cAMP/Epac/PLC-{epsilon} pathway. Black-Right-Pointing-Pointer Activation of TGR5 by bile salts and selective ligands causes insulin secretion. Black-Right-Pointing-Pointer TGR5 could be a potential therapeutic target to treat diabetes. -- Abstract: Bile acids act as signaling molecules and stimulate the G protein coupled receptor, TGR5, in addition to nuclear farnesoid X receptor to regulate lipid, glucose and energy metabolism. Bile acid induced activation of TGR5 in the enteroendocrine cells promotes glucagon like peptide-1 (GLP-1) release, which has insulinotropic effect in the pancreatic {beta} cells. In the present study, we have identified the expression of TGR5 in pancreatic {beta} cell line MIN6 and also in mouse and human pancreatic islets. TGR5 selective ligands, oleanolic acid (OA) and INT-777 selectively activated G{alpha}{sub s} and caused an increase in intracellular cAMP and Ca{sup 2+}. OA and INT-777 also increased phosphoinositide (PI) hydrolysis and the increase was blocked by NF449 (a selective G{alpha}{sub s} inhibitor) or (U73122) (PI hydrolysis inhibitor). OA, INT-777 and lithocholic acid increased insulin release in MIN6 and human islets and the increase was inhibited by treatment with NF449, (U73122) or BAPTA-AM (chelator of calcium), but not with myristoylated PKI (PKA inhibitor), suggesting that the release is dependent on G{sub s}/cAMP/Ca{sup 2+} pathway. 8-pCPT-2 Prime -O-Me-cAMP, a cAMP analog, which activates Epac, but not PKA also stimulated PI hydrolysis. In conclusion, our study demonstrates that the TGR5 expressed in the pancreatic {beta} cells regulates insulin secretion and highlights the importance of ongoing therapeutic strategies targeting TGR5 in the control of glucose homeostasis.

Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

DEFF Research Database (Denmark)

Martens, Geert A; Jiang, Lei; Hellemans, Karine H

2011-01-01

The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...

The Long-Term Impact of Autoimmune Pancreatitis on Pancreatic Function, Quality of Life, and Life Expectancy

NARCIS (Netherlands)

Buijs, Jorie; Cahen, Djuna L.; van Heerde, Marianne J.; Rauws, Erik A.; de Buy Wenniger, Lucas J. Maillette; Hansen, Bettina E.; Biermann, Katharina; Verheij, Joanne; Vleggaar, Frank P.; Brink, Menno A.; Beuers, Ulrich H. W.; van Buuren, Henk R.; Bruno, Marco J.

2015-01-01

To evaluate the long-term outcome of autoimmune pancreatitis. Patients with at least 2 years of follow-up were included. Information was collected regarding disease characteristics, treatment outcome, diagnosed malignancies, and mortality. In addition, pancreatic function and quality of life were

STAT5 activity in pancreatic beta-cells influences the severity of diabetes in animal models of type 1 and 2 diabetes

DEFF Research Database (Denmark)

Jackerott, Malene; Møldrup, Annette; Thams, Peter

2006-01-01

Pancreatic beta-cell growth and survival and insulin production are stimulated by growth hormone and prolactin through activation of the transcription factor signal transducer and activator of transcription (STAT)5. To assess the role of STAT5 activity in beta-cells in vivo, we generated transgen...... and type 2 diabetes....... reduced beta-cell proliferation at 6 months of age. The inhibitory effect of high-fat diet or leptin on insulin secretion was diminished in isolated islets from RIP-DNSTAT5 mice compared with wild-type islets. Upon multiple low-dose streptozotocin treatment, RIP-DNSTAT5 mice exhibited higher plasma...... of glucose tolerance, whereas RIP-CASTAT5 mice were more glucose tolerant and less hyperleptinemic than wild-type mice. Although the pancreatic insulin content and relative beta-cell area were increased in high-fat diet-fed RIP-DNSTAT5 mice compared with wild-type or RIP-CASTAT5 mice, RIP-DNSTAT5 mice showed...

Aberrant accumulation of the diabetes autoantigen GAD65 in Golgi membranes in conditions of ER stress and autoimmunity

DEFF Research Database (Denmark)

Phelps, Edward A; Cianciaruso, Chiara; Michael, Iacovos P

2016-01-01

Pancreatic islet beta cells are particularly susceptible to endoplasmic reticulum (ER) stress, which is implicated in beta cell dysfunction and loss during the pathogenesis of type 1 diabetes (T1D). The peripheral membrane protein GAD65 is an autoantigen in human T1D. GAD65 synthesizes GABA......, an important autocrine and paracrine signaling molecule and a survival factor in islets. We show that ER stress in primary beta cells perturbs the palmitoylation cycle controlling GAD65 endomembrane distribution, resulting in aberrant accumulation of the palmitoylated form in trans-Golgi membranes...... release from stressed and/or damaged beta cells, triggering autoimmunity....

Renal involvement in patients with autoimmune pancreatitis: Ultrasound findings

International Nuclear Information System (INIS)

Sasiwimonphan, Kewalee; Gorman, Brian; Kawashima, Akira; Chari, Suresh T.; Takahashi, Naoki

2012-01-01

Objective: The purpose of our study was to retrospectively evaluate the ultrasound findings of renal involvement in patients with autoimmune pancreatitis. Methods: 15 patients with autoimmune pancreatitis (15 male, 0 female, mean age 66 years old, range 44–85) who had renal involvement documented on CT or MR and had abdominal ultrasound within 1 month were included. Ultrasound images were retrospectively reviewed for presence or absence of renal involvement. Shape and echogenicity of the renal lesions were recorded. Results: In 8 out of 15 patients, at least one renal lesion was identified on ultrasound with a total of 9 kidneys. In 7 kidneys, lesions appeared as ill-defined, non-mass like areas of decreased echogenicity. Three lesions showed associated irregular lobular thickening of the renal parenchyma with bulging contour and 1 showed focal area of parenchymal loss. In 2 kidneys, the lesions were seen as solitary or multiple hypoechoic mass-like areas. Ill-defined, non-mass like lesions on ultrasound corresponded to well-circumscribed wedge-shaped lesions in all but one case on CT or MR. Mass-like lesions on ultrasound corresponded to well-circumscribed round lesions on CT or MR. Conclusion: Most common ultrasound findings of renal involvement in patients with autoimmune pancreatitis were ill-defined area of decreased echogenicity.

Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.

Science.gov (United States)

Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire

2009-04-01

Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.

Advances in treatment of autoimmune pancreatitis

Directory of Open Access Journals (Sweden)

LI Ji

2013-07-01

Full Text Available Autoimmune pancreatitis (AIP is a type of chronic pancreatitis characterized by an autoimmune inflammatory process. Treatment protocols for AIP are still evolving. According to the articles about AIP treatment in recent years, the indications for steroid therapy include specific clinical manifestations (jaundice, abdominal pain, etc., markedly abnormal imaging findings, and extrapancreatic organ involvement. The initial dose of steroid (prednisone is usually 0.6 mg·kg-1·d-1 or 30-40 mg/d; after 3 weeks to 1 month of treatment with the initial dose, the dose is decreased by 5-10 mg every 1-2 weeks until it drops to 2.5-5 mg/d; this dose is maintained for 6 months to 3 years. No consensus has been reached on the adverse effect of steroid on diabetes mellitus complicating AIP. Immunosuppressive agents should be used for the patients with disease relapses or with important extrapancreatic organs involved. Rituximab might become one of the therapies for refractory AIP. Although some patients achieved remission after surgical treatment, surgery is still not recommended as a routine treatment protocol due to the complications after surgery.

Hypermethylation of MST1 in IgG4-related autoimmune pancreatitis and rheumatoid arthritis

Energy Technology Data Exchange (ETDEWEB)

Fukuhara, Takataro; Tomiyama, Takashi [Division of Gastroenterology and Hepatology, The Third Department of Internal Medicine, JST CREST, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan); Yasuda, Kaneki [Department of Urology and Andrology, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan); Ueda, Yoshihiro [Department of Molecular Genetics, Institute of Biomedical Science, and JST CREST, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan); Ozaki, Yoshio; Son, Yonsu; Nomura, Shosaku [Department of the First Department of Internal Medicine, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan); Uchida, Kazushige; Okazaki, Kazuichi [Division of Gastroenterology and Hepatology, The Third Department of Internal Medicine, JST CREST, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan); Kinashi, Tatsuo, E-mail: kinashi@takii.kmu.ac.jp [Department of Molecular Genetics, Institute of Biomedical Science, and JST CREST, Kansai Medical University, 2-5-1 Shin-machi, Hirakata, Osaka 573-1010 (Japan)

2015-08-07

The serine/threonine kinase Mst1 plays important roles in the control of immune cell trafficking, proliferation, and differentiation. Previously, we reported that Mst1 was required for thymocyte selection and regulatory T-cell functions, thereby the prevention of autoimmunity in mice. In humans, MST1 null mutations cause T-cell immunodeficiency and hypergammaglobulinemia with autoantibody production. RASSF5C(RAPL) is an activator of MST1 and it is frequently methylated in some tumors. Herein, we investigated methylation of the promoter regions of MST1 and RASSF5C(RAPL) in leukocytes from patients with IgG4-related autoimmune pancreatitis (AIP) and rheumatoid arthritis (RA). Increased number of CpG methylation in the 5′ region of MST1 was detected in AIP patients with extrapancreatic lesions, whereas AIP patients without extrapancreatic lesions were similar to controls. In RA patients, we detected a slight increased CpG methylation in MST1, although the overall number of methylation sites was lower than that of AIP patients with extrapancreatic lesions. There were no significant changes of the methylation levels of the CpG islands in the 5′ region of RASSF5C(RAPL) in leukocytes from AIP and RA patients. Consistently, we found a significantly down-regulated expression of MST1 in regulatory T cells of AIP patients. Our results suggest that the decreased expression of MST1 in regulatory T cells due to hypermethylation of the promoter contributes to the pathogenesis of IgG4-related AIP. - Highlights: • Mst1 controls immune cells trafficking, cell proliferation and differentiation. • Autoimmune pancreatitis (AIP) is an idiopathic pancreatitis affecting multiple organs. • Decreased MST1 expression and increased CpG methylation of promoter of MST1 in AIP. • Slight increased CpG methylation of MST1 in rheumatoid arthritis patients. • MST1 contributes pathogenesis of IgG4-related AIP.

Hypermethylation of MST1 in IgG4-related autoimmune pancreatitis and rheumatoid arthritis

International Nuclear Information System (INIS)

Fukuhara, Takataro; Tomiyama, Takashi; Yasuda, Kaneki; Ueda, Yoshihiro; Ozaki, Yoshio; Son, Yonsu; Nomura, Shosaku; Uchida, Kazushige; Okazaki, Kazuichi; Kinashi, Tatsuo

2015-01-01

The serine/threonine kinase Mst1 plays important roles in the control of immune cell trafficking, proliferation, and differentiation. Previously, we reported that Mst1 was required for thymocyte selection and regulatory T-cell functions, thereby the prevention of autoimmunity in mice. In humans, MST1 null mutations cause T-cell immunodeficiency and hypergammaglobulinemia with autoantibody production. RASSF5C(RAPL) is an activator of MST1 and it is frequently methylated in some tumors. Herein, we investigated methylation of the promoter regions of MST1 and RASSF5C(RAPL) in leukocytes from patients with IgG4-related autoimmune pancreatitis (AIP) and rheumatoid arthritis (RA). Increased number of CpG methylation in the 5′ region of MST1 was detected in AIP patients with extrapancreatic lesions, whereas AIP patients without extrapancreatic lesions were similar to controls. In RA patients, we detected a slight increased CpG methylation in MST1, although the overall number of methylation sites was lower than that of AIP patients with extrapancreatic lesions. There were no significant changes of the methylation levels of the CpG islands in the 5′ region of RASSF5C(RAPL) in leukocytes from AIP and RA patients. Consistently, we found a significantly down-regulated expression of MST1 in regulatory T cells of AIP patients. Our results suggest that the decreased expression of MST1 in regulatory T cells due to hypermethylation of the promoter contributes to the pathogenesis of IgG4-related AIP. - Highlights: • Mst1 controls immune cells trafficking, cell proliferation and differentiation. • Autoimmune pancreatitis (AIP) is an idiopathic pancreatitis affecting multiple organs. • Decreased MST1 expression and increased CpG methylation of promoter of MST1 in AIP. • Slight increased CpG methylation of MST1 in rheumatoid arthritis patients. • MST1 contributes pathogenesis of IgG4-related AIP

Involvement of interleukin 1 and interleukin 1 antagonist in pancreatic beta-cell destruction in insulin-dependent diabetes mellitus

DEFF Research Database (Denmark)

Mandrup-Poulsen, T; Zumsteg, U; Reimers, J

1993-01-01

In this review we propose that the balance between the action of interleukin 1 (IL-1) and its natural antagonist IL-1ra on the level of the insulin-producing pancreatic beta-cell may play a decisive role in the pathogenesis of insulin-dependent diabetes mellitus (IDDM). We argue that IL-1...... potentiated by other cytokines (tumor necrosis factor alpha, interferon gamma) is an important effector molecule involved in both early and late events in the immune-mediated process that leads to beta-cell destruction and IDDM. We also point out that surprisingly high molar excesses of IL-1ra over IL-1...... are necessary to block the action of IL-1 on islet beta-cells compared to islet alpha-cells in vitro and in animals. We suggest that the selectivity of beta-cell destruction in IDDM may be conferred on several levels: (1) homing of beta-cell antigen specific T cells, (2) targeted delivery of cytokines...

Selective destruction of mouse islet beta cells by human T lymphocytes in a newly-established humanized type 1 diabetic model

Energy Technology Data Exchange (ETDEWEB)

Zhao, Yong, E-mail: yongzhao@uic.edu [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Guo, Chengshan; Hwang, David; Lin, Brian; Dingeldein, Michael; Mihailescu, Dan; Sam, Susan; Sidhwani, Seema [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Zhang, Yongkang [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Jain, Sumit [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Skidgel, Randal A. [Department of Pharmacology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Prabhakar, Bellur S. [Department of Immunology and Microbiology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Mazzone, Theodore [Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612 (United States); Holterman, Mark J. [Department of Surgery, University of Illinois at Chicago, Chicago, IL 60612 (United States)

2010-09-03

Research highlights: {yields} Establish a human immune-mediated type 1 diabetic model in NOD-scid IL2r{gamma}{sup null} mice. {yields} Using the irradiated diabetic NOD mouse spleen mononuclear cells as trigger. {yields} The islet {beta} cells were selectively destroyed by infiltrated human T cells. {yields} The model can facilitate translational research to find a cure for type 1 diabetes. -- Abstract: Type 1 diabetes (T1D) is caused by a T cell-mediated autoimmune response that leads to the loss of insulin-producing {beta} cells. The optimal preclinical testing of promising therapies would be aided by a humanized immune-mediated T1D model. We develop this model in NOD-scid IL2r{gamma}{sup null} mice. The selective destruction of pancreatic islet {beta} cells was mediated by human T lymphocytes after an initial trigger was supplied by the injection of irradiated spleen mononuclear cells (SMC) from diabetic nonobese diabetic (NOD) mice. This resulted in severe insulitis, a marked loss of total {beta}-cell mass, and other related phenotypes of T1D. The migration of human T cells to pancreatic islets was controlled by the {beta} cell-produced highly conserved chemokine stromal cell-derived factor 1 (SDF-1) and its receptor C-X-C chemokine receptor (CXCR) 4, as demonstrated by in vivo blocking experiments using antibody to CXCR4. The specificity of humanized T cell-mediated immune responses against islet {beta} cells was generated by the local inflammatory microenvironment in pancreatic islets including human CD4{sup +} T cell infiltration and clonal expansion, and the mouse islet {beta}-cell-derived CD1d-mediated human iNKT activation. The selective destruction of mouse islet {beta} cells by a human T cell-mediated immune response in this humanized T1D model can mimic those observed in T1D patients. This model can provide a valuable tool for translational research into T1D.

Pathway decision-making strategies for generating pancreatic beta-cells: systems biology or hit and miss?

Science.gov (United States)

Jensen, Jan

2007-08-01

Method selection strategies to achieve beta-cell differentiation from human embryonic stem cells are reviewed. Expectations are high for an embryonic stem cell derived cellular replacement method to cure diabetes, and recent observations indicate that mature beta-cells can be derived from human embryonic stem cells. In terms of the translational setting, however, we are not there yet; conversion of embryonic stem cells to fully mature beta-cells is not effective and does not provide an exclusive beta-cell population as the end-product. Studies emphasize that expecting development of a 'magic media bullet' that promotes endocrine fate is rather optimistic; consecutive administration of signaling inducers, carefully provided to mimic normal development, is more likely to succeed. To accomplish this task we need better understanding of the extracellular signaling pathways that drive progressive endodermal fate choices throughout development. Knowledge of cell-intrinsic control of fate assignments in pancreas is growing rapidly. Nevertheless, insufficient information regarding morphogen codes that operate in endoderm and pancreas is hindering development of better, directed differentiation schema of uncommitted embryonic stem cells toward endodermal, pancreatic, and subsequent endocrine specific fates. A systematic approach to defining morphogen codes in developing endoderm and pancreas appears timely and justified.

Antioxidant and regulatory role of mitochondrial uncoupling protein UCP2 in pancreatic beta-cells

Czech Academy of Sciences Publication Activity Database

Ježek, Petr; Olejár, Tomáš; Smolková, Katarína; Ježek, Jan; Dlasková, Andrea; Plecitá-Hlavatá, Lydie; Zelenka, Jaroslav; Špaček, Tomáš; Engstová, Hana; Reguera Pajuelo, David; Jabůrek, Martin

2014-01-01

Roč. 63, Suppl.1 (2014), S73-S91 ISSN 0862-8408 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GAP305/12/1247; GA ČR(CZ) GPP304/10/P204; GA MŠk(CZ) EE2.3.30.0025 Institutional support: RVO:67985823 Keywords : mitochondria * uncoupling protein UCP2 * pancreatic beta-cells * reactive oxygen species * glucose-stimulated insulin secretion Subject RIV: EA - Cell Biology Impact factor: 1.293, year: 2014

EX4 stabilizes and activates Nrf2 via PKCδ, contributing to the prevention of oxidative stress-induced pancreatic beta cell damage

Energy Technology Data Exchange (ETDEWEB)

Kim, Mi-Hwi; Kim, Eung-Hwi [College of Pharmacy, Gachon Institute of Pharmaceutical Science, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Jung, Hye Seung [Department of Internal Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Yang, Dongki [Department of Physiology, Gachon University College of Medicine, Incheon (Korea, Republic of); Park, Eun-Young, E-mail: parkey@mokpo.ac.kr [College of Pharmacy, Natural Medicine Research Institute, Mokpo National University, Muan-gun, Jeonnam (Korea, Republic of); Jun, Hee-Sook, E-mail: hsjun@gachon.ac.kr [College of Pharmacy, Gachon Institute of Pharmaceutical Science, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Yeonsu-ku, Incheon (Korea, Republic of); Gachon Medical Research Institute, Gil Hospital, Incheon (Korea, Republic of)

2017-01-15

Oxidative stress in pancreatic beta cells can inhibit insulin secretion and promote apoptotic cell death. Exendin-4 (EX4), a glucagon-like peptide-1 receptor agonist, can suppress beta cell apoptosis, improve beta cell function and protect against oxidative damage. In this study, we investigated the molecular mechanisms for antioxidative effects of EX4 in pancreatic beta cells. INS-1 cells, a rat insulinoma cell line, were pretreated with EX4 and exposed to palmitate or H{sub 2}O{sub 2}. Reactive oxygen species (ROS) production, and glutathione and insulin secretion were measured. The mRNA and protein expression levels of antioxidant genes were examined. The level of nuclear factor erythroid 2-related factor 2 (Nrf2), its binding to antioxidant response element (ARE), and its ubiquination in the presence of EX4 were determined. The Nrf2 signaling pathway was determined using rottlerin (protein kinase [PK]Cδ inhibitor), H89 (PKA inhibitor) and LY294002 (phosphatidylinositide 3-kinase [PI3K] inhibitor). EX4 treatment decreased ROS production, recovered cellular glutathione levels and insulin secretion in the presence of oxidative stress in INS-1 cells. The expression levels of glutamate-cysteine ligase catalytic subunit and heme oxygenase-1 were increased by EX4 treatment. EX4 promoted Nrf2 translocation, ARE binding activity and enhanced stabilization of Nrf2 by inhibition of ubiquitination. Knockdown of Nrf2 abolished the effect of EX4 on increased insulin secretion. Inhibition of PKCδ attenuated Nrf2 translocation and antioxidative gene expression by EX4 treatment. We suggest that EX4 activates and stabilizes Nrf2 through PKCδ activation, contributing to the increase of antioxidant gene expression and consequently improving beta cell function in the presence of oxidative stress. - Highlights: • EX4 protects against oxidative stress-induced pancreatic beta cell dysfunction. • EX4 increases antioxidant gene expression. • Antioxidative effect of EX4 is

EX4 stabilizes and activates Nrf2 via PKCδ, contributing to the prevention of oxidative stress-induced pancreatic beta cell damage

International Nuclear Information System (INIS)

Kim, Mi-Hwi; Kim, Eung-Hwi; Jung, Hye Seung; Yang, Dongki; Park, Eun-Young; Jun, Hee-Sook

2017-01-01

Oxidative stress in pancreatic beta cells can inhibit insulin secretion and promote apoptotic cell death. Exendin-4 (EX4), a glucagon-like peptide-1 receptor agonist, can suppress beta cell apoptosis, improve beta cell function and protect against oxidative damage. In this study, we investigated the molecular mechanisms for antioxidative effects of EX4 in pancreatic beta cells. INS-1 cells, a rat insulinoma cell line, were pretreated with EX4 and exposed to palmitate or H 2 O 2 . Reactive oxygen species (ROS) production, and glutathione and insulin secretion were measured. The mRNA and protein expression levels of antioxidant genes were examined. The level of nuclear factor erythroid 2-related factor 2 (Nrf2), its binding to antioxidant response element (ARE), and its ubiquination in the presence of EX4 were determined. The Nrf2 signaling pathway was determined using rottlerin (protein kinase [PK]Cδ inhibitor), H89 (PKA inhibitor) and LY294002 (phosphatidylinositide 3-kinase [PI3K] inhibitor). EX4 treatment decreased ROS production, recovered cellular glutathione levels and insulin secretion in the presence of oxidative stress in INS-1 cells. The expression levels of glutamate-cysteine ligase catalytic subunit and heme oxygenase-1 were increased by EX4 treatment. EX4 promoted Nrf2 translocation, ARE binding activity and enhanced stabilization of Nrf2 by inhibition of ubiquitination. Knockdown of Nrf2 abolished the effect of EX4 on increased insulin secretion. Inhibition of PKCδ attenuated Nrf2 translocation and antioxidative gene expression by EX4 treatment. We suggest that EX4 activates and stabilizes Nrf2 through PKCδ activation, contributing to the increase of antioxidant gene expression and consequently improving beta cell function in the presence of oxidative stress. - Highlights: • EX4 protects against oxidative stress-induced pancreatic beta cell dysfunction. • EX4 increases antioxidant gene expression. • Antioxidative effect of EX4 is mediated by

Autoimmune gastro-pancreatitis with anti-protein disulfide isomerase-associated 2 autoantibody in Aire-deficient BALB/cAnN mice.

Directory of Open Access Journals (Sweden)

Hironori Kurisaki

Full Text Available Although the autoimmune regulator (Aire knockout (KO mouse model has been reported to present various organ-specific autoimmune diseases depending on genetic background, autoimmune pancreatitis in mice of BALB/c background has not yet been reported. Here, we report that Aire KO mice with BALB/cAnN background showed significant lymphoid cell infiltration in the pancreas and stomach. To examine whether the phenotype in the pancreas and stomach is due to autoimmune reaction associated with autoantibody production, indirect immunofluorescence staining followed by Western blot analysis was performed. Consequently, the autoantibody against pancreas and stomach was detected in the sera of Aire KO mice, and the target antigen of the autoantibody was identified as protein disulfide isomerase-associated 2 (Pdia2, which was reported to be expressed preferentially in the pancreas and stomach. Thus, Aire KO mice of BALB/cAnN background can serve as a useful animal model for autoimmune gastro-pancreatitis with anti-Pdia2 autoantibody production.

Autoimmune gastro-pancreatitis with anti-protein disulfide isomerase-associated 2 autoantibody in Aire-deficient BALB/cAnN mice.

Science.gov (United States)

Kurisaki, Hironori; Nagao, Yukihiro; Nagafuchi, Seiho; Mitsuyama, Masao

2013-01-01

Although the autoimmune regulator (Aire) knockout (KO) mouse model has been reported to present various organ-specific autoimmune diseases depending on genetic background, autoimmune pancreatitis in mice of BALB/c background has not yet been reported. Here, we report that Aire KO mice with BALB/cAnN background showed significant lymphoid cell infiltration in the pancreas and stomach. To examine whether the phenotype in the pancreas and stomach is due to autoimmune reaction associated with autoantibody production, indirect immunofluorescence staining followed by Western blot analysis was performed. Consequently, the autoantibody against pancreas and stomach was detected in the sera of Aire KO mice, and the target antigen of the autoantibody was identified as protein disulfide isomerase-associated 2 (Pdia2), which was reported to be expressed preferentially in the pancreas and stomach. Thus, Aire KO mice of BALB/cAnN background can serve as a useful animal model for autoimmune gastro-pancreatitis with anti-Pdia2 autoantibody production.

Inter-domain tagging implicates caveolin-1 in insulin receptor trafficking and Erk signaling bias in pancreatic beta-cells

Directory of Open Access Journals (Sweden)

Tobias Boothe

2016-05-01

Full Text Available Objective: The role and mechanisms of insulin receptor internalization remain incompletely understood. Previous trafficking studies of insulin receptors involved fluorescent protein tagging at their termini, manipulations that may be expected to result in dysfunctional receptors. Our objective was to determine the trafficking route and molecular mechanisms of functional tagged insulin receptors and endogenous insulin receptors in pancreatic beta-cells. Methods: We generated functional insulin receptors tagged with pH-resistant fluorescent proteins between domains. Confocal, TIRF and STED imaging revealed a trafficking pattern of inter-domain tagged insulin receptors and endogenous insulin receptors detected with antibodies. Results: Surprisingly, interdomain-tagged and endogenous insulin receptors in beta-cells bypassed classical Rab5a- or Rab7-mediated endocytic routes. Instead, we found that removal of insulin receptors from the plasma membrane involved tyrosine-phosphorylated caveolin-1, prior to trafficking within flotillin-1-positive structures to lysosomes. Multiple methods of inhibiting caveolin-1 significantly reduced Erk activation in vitro or in vivo, while leaving Akt signaling mostly intact. Conclusions: We conclude that phosphorylated caveolin-1 plays a role in insulin receptor internalization towards lysosomes through flotillin-1-positive structures and that caveolin-1 helps bias physiological beta-cell insulin signaling towards Erk activation. Author Video: Author Video Watch what authors say about their articles Keywords: Insulin receptor internalization, Insulin resistance, Pancreatic islet beta-cells, Autocrine insulin signaling

Tissue-specific methylation of human insulin gene and PCR assay for monitoring beta cell death.

Directory of Open Access Journals (Sweden)

Mohamed I Husseiny

Full Text Available The onset of metabolic dysregulation in type 1 diabetes (T1D occurs after autoimmune destruction of the majority of pancreatic insulin-producing beta cells. We previously demonstrated that the DNA encoding the insulin gene is uniquely unmethylated in these cells and then developed a methylation-specific PCR (MSP assay to identify circulating beta cell DNA in streptozotocin-treated mice prior to the rise in blood glucose. The current study extends to autoimmune non-obese diabetic (NOD mice and humans, showing in NOD mice that beta cell death occurs six weeks before the rise in blood sugar and coincides with the onset of islet infiltration by immune cells, demonstrating the utility of MSP for monitoring T1D. We previously reported unique patterns of methylation of the human insulin gene, and now extend this to other human tissues. The methylation patterns of the human insulin promoter, intron 1, exon 2, and intron 2 were determined in several normal human tissues. Similar to our previous report, the human insulin promoter was unmethylated in beta cells, but methylated in all other tissues tested. In contrast, intron 1, exon 2 and intron 2 did not exhibit any tissue-specific DNA methylation pattern. Subsequently, a human MSP assay was developed based on the methylation pattern of the insulin promoter and human islet DNA was successfully detected in circulation of T1D patients after islet transplantation therapy. Signal levels of normal controls and pre-transplant samples were shown to be similar, but increased dramatically after islet transplantation. In plasma the signal declines with time but in whole blood remains elevated for at least two weeks, indicating that association of beta cell DNA with blood cells prolongs the signal. This assay provides an effective method to monitor beta cell destruction in early T1D and in islet transplantation therapy.

[Membranous nephropathy associated to autoimmune thyroiditis, chronic pancreatitis and suprarrenal insufficiency].

Science.gov (United States)

Merino, J L; Fernández Lucas, M; Teruel, J L; Valer, P; Moreira, V; Arambarri, M; Ortuño, J

2004-01-01

A 33 year old female was admitted to the hospital to study aedema and bocio, A nephrotic syndrome was diagnosed and the renal biopsy demonstrated membranous glomerulonephritis, stage II. She was also diagnosed of Hashimoto's autoinmmune thyroiditis: TSH (41.5 uUl/ml), T4 (0.07 ng/dl), antithyroglobuline (1/2560) and antimicrosome (1/6400). Four year latter she was diagnosed of autoinmmune pancreatitis, without evidence of diabetes mellitus or exocrine pancreatic insufficiency. Eight years latter she was diagnosed of primary autoimmune suprarrenal insufficiency: basal cortisol: 2.7 mcg/dl, post ACTH estimulated cortisol: 5.6 mcg/dl, antinuclear antibody (1/160) and antiparietal (1/320). We present a pluriglandular autoimmune syndrome with membranous glomerulonephritis, thyroiditis, pancreatitis and suprarrenal insufficiency. To the best of our knowledge this complex syndrome has not been previously described.

Sirt1 regulates insulin secretion by repressing UCP2 in pancreatic beta cells.

Directory of Open Access Journals (Sweden)

Laura Bordone

2006-02-01

Full Text Available Sir2 and insulin/IGF-1 are the major pathways that impinge upon aging in lower organisms. In Caenorhabditis elegans a possible genetic link between Sir2 and the insulin/IGF-1 pathway has been reported. Here we investigate such a link in mammals. We show that Sirt1 positively regulates insulin secretion in pancreatic beta cells. Sirt1 represses the uncoupling protein (UCP gene UCP2 by binding directly to the UCP2 promoter. In beta cell lines in which Sirt1 is reduced by SiRNA, UCP2 levels are elevated and insulin secretion is blunted. The up-regulation of UCP2 is associated with a failure of cells to increase ATP levels after glucose stimulation. Knockdown of UCP2 restores the ability to secrete insulin in cells with reduced Sirt1, showing that UCP2 causes the defect in glucose-stimulated insulin secretion. Food deprivation induces UCP2 in mouse pancreas, which may occur via a reduction in NAD (a derivative of niacin levels in the pancreas and down-regulation of Sirt1. Sirt1 knockout mice display constitutively high UCP2 expression. Our findings show that Sirt1 regulates UCP2 in beta cells to affect insulin secretion.

Human beta-cell precursors mature into functional insulin-producing cells in an immunoisolation device: implications for diabetes cell therapies.

Science.gov (United States)

Lee, Seung-Hee; Hao, Ergeng; Savinov, Alexei Y; Geron, Ifat; Strongin, Alex Y; Itkin-Ansari, Pamela

2009-04-15

Islet transplantation is limited by the need for chronic immunosuppression and the paucity of donor tissue. As new sources of human beta-cells are developed (e.g., stem cell-derived tissue), transplanting them in a durable device could obviate the need for immunosuppression, while also protecting the patient from any risk of tumorigenicity. Here, we studied (1) the survival and function of encapsulated human beta-cells and their progenitors and (2) the engraftment of encapsulated murine beta-cells in allo- and autoimmune settings. Human islets and human fetal pancreatic islet-like cell clusters were encapsulated in polytetrafluorethylene devices (TheraCyte) and transplanted into immunodeficient mice. Graft survival and function was measured by immunohistochemistry, circulating human C-peptide levels, and blood glucose levels. Bioluminescent imaging was used to monitor encapsulated neonatal murine islets. Encapsulated human islet-like cell clusters survived, replicated, and acquired a level of glucose responsive insulin secretion sufficient to ameliorate hyperglycemia in diabetic mice. Bioluminescent imaging of encapsulated murine neonatal islets revealed a dynamic process of cell death followed by regrowth, resulting in robust long-term allograft survival. Further, in the non-obese diabetic (NOD) mouse model of type I diabetes, encapsulated primary beta-cells ameliorated diabetes without stimulating a detectable T-cell response. We demonstrate for the first time that human beta-cells function is compatible with encapsulation in a durable, immunoprotective device. Moreover, our study suggests that encapsulation of beta-cells before terminal differentiation will be a successful approach for new cell-based therapies for diabetes, such as those derived from stem cells.

The Role of Oxidative Stress and Hypoxia in Pancreatic Beta-Cell Dysfunction in Diabetes Mellitus.

Science.gov (United States)

Gerber, Philipp A; Rutter, Guy A

2017-04-01

Metabolic syndrome is a frequent precursor of type 2 diabetes mellitus (T2D), a disease that currently affects ∼8% of the adult population worldwide. Pancreatic beta-cell dysfunction and loss are central to the disease process, although understanding of the underlying molecular mechanisms is still fragmentary. Recent Advances: Oversupply of nutrients, including glucose and fatty acids, and the subsequent overstimulation of beta cells, are believed to be an important contributor to insulin secretory failure in T2D. Hypoxia has also recently been implicated in beta-cell damage. Accumulating evidence points to a role for oxidative stress in both processes. Although the production of reactive oxygen species (ROS) results from enhanced mitochondrial respiration during stimulation with glucose and other fuels, the expression of antioxidant defense genes is unusually low (or disallowed) in beta cells. Not all subjects with metabolic syndrome and hyperglycemia go on to develop full-blown diabetes, implying an important role in disease risk for gene-environment interactions. Possession of common risk alleles at the SLC30A8 locus, encoding the beta-cell granule zinc transporter ZnT8, may affect cytosolic Zn 2+ concentrations and thus susceptibility to hypoxia and oxidative stress. Loss of normal beta-cell function, rather than total mass, is increasingly considered to be the major driver for impaired insulin secretion in diabetes. Better understanding of the role of oxidative changes, its modulation by genes involved in disease risk, and effects on beta-cell identity may facilitate the development of new therapeutic strategies to this disease. Antioxid. Redox Signal. 26, 501-518.

MRI findings of pancreatic lymphoma and autoimmune pancreatitis: A comparative study

Energy Technology Data Exchange (ETDEWEB)

Ishigami, Kousei, E-mail: Ishigamikousei@aol.co [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Tajima, Tsuyoshi; Nishie, Akihiro; Ushijima, Yasuhiro [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Fujita, Nobuhiro [Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University (Japan); Asayama, Yoshiki; Kakihara, Daisuke; Irie, Hiroyuki [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan); Ito, Tetsuhide; Igarashi, Hisato [Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University (Japan); Nakamura, Masafumi [Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582 (Japan)

2010-06-15

Purpose: To clarify whether there are differences in MRI findings between pancreatic lymphomas and autoimmune pancreatitis (AIP). Materials and methods: MRI of 8 patients with pancreatic lymphomas and 21 patients with AIP were retrospectively reviewed. For multifocal pancreatic lymphomas (n = 2) and AIP (n = 4), the largest 2 lesions were evaluated. Ten pancreatic lymphomas and 25 AIP were compared on three bases: the signal intensity on T2-weighted images, internal homogeneity, and presence or absence of capsule-like rim. In 8 lymphomas and 19 AIP, the enhancement pattern on dynamic MRI was compared, as well. Results: On T2-weighted images, pancreatic lymphomas comprised 5, 5 and 4 lesions with low (iso), slightly high, and moderately high intensity, respectively, while the numbers for AIP were 14, 10, and 1 (P < 0.01). Nine of 10 (90%) lymphomas appeared homogenous, and 11 of 25 (44%) AIP were homogenous (P < 0.05). A capsule-like rim was present in 9 of 25 (36%) AIP, but was not seen in lymphomas (P < 0.05). On dynamic MRI, 18 of 19 (94.7%) AIP showed persistent (n = 5) or delayed enhancement (n = 13), and 6 of 8 (75%) lymphomas showed low intensity without delayed enhancement (P < 0.001). Conclusion: MRI findings for pancreatic lymphomas and AIP were significantly different, which may be helpful for the differential diagnosis of these two diseases.

Islet Cells Serve as Cells of Origin of Pancreatic Gastrin-Positive Endocrine Tumors.

Science.gov (United States)

Bonnavion, Rémy; Teinturier, Romain; Jaafar, Rami; Ripoche, Doriane; Leteurtre, Emmanuelle; Chen, Yuan-Jia; Rehfeld, Jens F; Lepinasse, Florian; Hervieu, Valérie; Pattou, François; Vantyghem, Marie-Christine; Scoazec, Jean-Yves; Bertolino, Philippe; Zhang, Chang Xian

2015-10-01

The cells of origin of pancreatic gastrinomas remain an enigma, since no gastrin-expressing cells are found in the normal adult pancreas. It was proposed that the cellular origin of pancreatic gastrinomas may come from either the pancreatic cells themselves or gastrin-expressing cells which have migrated from the duodenum. In the current study, we further characterized previously described transient pancreatic gastrin-expressing cells using cell lineage tracing in a pan-pancreatic progenitor and a pancreatic endocrine progenitor model. We provide evidence showing that pancreatic gastrin-expressing cells, found from embryonic day 12.5 until postnatal day 7, are derived from pancreatic Ptf1a(+) and neurogenin 3-expressing (Ngn3(+)) progenitors. Importantly, the majority of them coexpress glucagon, with 4% coexpressing insulin, indicating that they are a temporary subpopulation of both alpha and beta cells. Interestingly, Men1 disruption in both Ngn3 progenitors and beta and alpha cells resulted in the development of pancreatic gastrin-expressing tumors, suggesting that the latter developed from islet cells. Finally, we detected gastrin expression using three human cohorts with pancreatic endocrine tumors (pNETs) that have not been diagnosed as gastrinomas (in 9/34 pNETs from 6/14 patients with multiple endocrine neoplasia type 1, in 5/35 sporadic nonfunctioning pNETs, and in 2/20 sporadic insulinomas), consistent with observations made in mouse models. Our work provides insight into the histogenesis of pancreatic gastrin-expressing tumors. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

E2-2 Dependent Plasmacytoid Dendritic Cells Control Autoimmune Diabetes.

Directory of Open Access Journals (Sweden)

Lisbeth Hansen

Full Text Available Autoimmune diabetes is a consequence of immune-cell infiltration and destruction of pancreatic β-cells in the islets of Langerhans. We analyzed the cellular composition of the insulitic lesions in the autoimmune-prone non-obese diabetic (NOD mouse and observed a peak in recruitment of plasmacytoid dendritic cells (pDCs to NOD islets around 8-9 weeks of age. This peak coincides with increased spontaneous expression of type-1-IFN response genes and CpG1585 induced production of IFN-α from NOD islets. The transcription factor E2-2 is specifically required for the maturation of pDCs, and we show that knocking out E2-2 conditionally in CD11c+ cells leads to a reduced recruitment of pDCs to pancreatic islets and reduced CpG1585 induced production of IFN-α during insulitis. As a consequence, insulitis has a less aggressive expression profile of the Th1 cytokine IFN-γ and a markedly reduced diabetes incidence. Collectively, these observations demonstrate a disease-promoting role of E2-2 dependent pDCs in the pancreas during autoimmune diabetes in the NOD mouse.

Adult Human Pancreatic Islet Beta-Cells Display Limited Turnover and Long Lifespan as Determined by In-Vivo Thymidine Analog Incorporation and Radiocarbon Dating

Energy Technology Data Exchange (ETDEWEB)

Perl, S; Kushner, J A; Buchholz, B A; Meeker, A K; Stein, G M; Hsieh, M; Kirby, M; Pechhold, S; Liu, E H; Harlan, D M; Tisdale, J F

2010-03-15

Diabetes mellitus results from an absolute or relative deficiency of insulin producing pancreatic beta-cells. The adult human beta-cell's turnover rate remains unknown. We employed novel techniques to examine adult human islet beta-cell turnover and longevity in vivo. Subjects enrolled in NIH clinical trials received thymidine analogues [iododeoxyuridine (IdU) or bromodeoxyuridine (BrdU)] 8-days to 4-years prior to death. Archival autopsy samples from ten patients (aged 17-74 years) were employed to assess beta-cell turnover by scoring nuclear analog labeling within insulin staining cells. Human adult beta-cell longevity was determined by estimating the cells genomic DNA integration of atmospheric carbon-14 ({sup 14}C). DNA was purified from pancreatic islets isolated from cadaveric donors; whole islet prep DNA was obtained from a 15 year old donor, and purified beta-cell DNA was obtained from two donors (age 48 and 80 years). {sup 14}C levels were then determined using accelerator mass spectrometry (AMS). Cellular 'birth date' was determined by comparing the subject's DNA {sup 14}C content relative to a well-established {sup 14}C atmospheric prevalence curve. In the two subjects less than age 20 years, 1-2% of the beta-cell nuclei co-stained for BrdU/IdU. No beta-cell nuclei co-stained in the eight patients more than 30 years old. Consistent with the BrdU/IdU turnover data, beta-cell DNA {sup 14}C content indicated the cells 'birth date' occurred within the subject's first 30 years of life. Under typical circumstances, adult human beta-cells and their cellular precursors are established by young adulthood.

Autoimmune Pancreatitis Can Transform Into Chronic Features Similar to Advanced Chronic Pancreatitis With Functional Insufficiency Following Severe Calcification.

Science.gov (United States)

Kanai, Keita; Maruyama, Masahiro; Kameko, Fumiko; Kawasaki, Kenji; Asano, Junpei; Oguchi, Takaya; Watanabe, Takayuki; Ito, Tetsuya; Muraki, Takashi; Hamano, Hideaki; Matsumoto, Akihiro; Arakura, Norikazu; Kawa, Shigeyuki

2016-09-01

Because several studies for autoimmune pancreatitis (AIP) have revealed pancreatic calcification resembling that in chronic pancreatitis (CP), we sought to clarify whether AIP could transform into chronic features similar to advanced CP with severe pancreatic dysfunction. Pancreatic functions of 92 AIP patients, 47 definite CP patients, and 30 healthy controls were assessed by fecal elastase-1 concentration (FEC), fasting immunoreactive insulin (IRI), and homeostatic model assessment (HOMA)-R. The 92 AIP patients included 17 (18%) with severe calcification (SC) and 75 without. The FEC levels in AIP and CP patients were significantly lower than that in controls. Exocrine insufficiency defined as FEC less than 200 μg/g was 39% in AIP without SC, 56% in AIP with SC, and 74% in CP. Fasting IRI and C-peptide reactivity values in CP were significantly lower than those in AIP, with no significant differences between AIP subgroups. The prevalence of endocrine insufficiency according to fasting IRI less than 5.0 μU/mL was 26% in AIP without SC, 31% in AIP with SC, and 59% in CP, respectively. HOMA-R values were significantly higher in all AIP groups than in CP. Autoimmune pancreatitis can transform into a state of pancreatic insufficiency after calcification that is less severe than that in definite CP.

Pancreatic beta cell function increases in a linear dose-response manner following exercise training in adults with prediabetes

DEFF Research Database (Denmark)

Malin, Steven K; Solomon, Thomas; Blaszczak, Alecia

2013-01-01

While some studies suggest that a linear dose-response relationship exists between exercise and insulin sensitivity, the exercise dose required to enhance pancreatic beta-cell function is unknown. Thirty-five older, obese adults with prediabetes underwent a progressive 12-week supervised exercise...

Renal lesions associated with autoimmune pancreatitis: CT findings

International Nuclear Information System (INIS)

Triantopoulou, Charikleia; Maniatis, Petros; Siafas, Ioannis; Papailiou, John; Malachias, George; Anastopoulos, John

2010-01-01

Background: Autoimmune pancreatitis (AIP) is a chronic inflammatory condition characterized by IgG4-positive plasma cells. Recent evidence suggests that it is a systemic disease affecting various organs. Tubulointerstitial nephritis has been reported in association with AIP. Purpose: To investigate the incidence and types of renal involvement in patients with AIP. Material and Methods: Eighteen patients with no history of renal disease and a diagnosis of AIP (on the basis of histopathologic findings or a combination of characteristic imaging features, increased serum IgG4 levels, and response to steroid treatment) were included. All patients underwent computed tomography (CT) imaging and follow-up ranged from 6 months to 2 years. CT images were reviewed for the presence of renal lesions. Results: Seven patients had renal involvement (38.8%). None of the lesions was visible on non-contrast-enhanced CT scan. Parenchymal lesions appeared as multiple nodules showing decreased enhancement (four cases). Pyelonephritis, lymphoma, and metastases were considered in the differential diagnosis. An ill-defined low-attenuation mass-like lesion was found in one patient, while diffuse thickening of the renal pelvis wall was evident in the last two cases. Renal lesions regressed in all patients after steroid treatment, the larger one leaving a fibrous cortical scar. Conclusion: Different types of renal lesions in patients with AIP are relatively common, appearing as multiple nodules with decreased enhancement. These findings support the proposed concept of an IgG4-related systemic disease. Autoimmune disease should be suspected in cases of renal involvement in association with pancreatic focal or diffuse enlargement.

Renal lesions associated with autoimmune pancreatitis: CT findings

Energy Technology Data Exchange (ETDEWEB)

Triantopoulou, Charikleia; Maniatis, Petros; Siafas, Ioannis; Papailiou, John (CT and Radiology Dept., ' Konstantopouleion' General Hospital, Athens (Greece)), e-mail: ctriantopoulou@gmail.com; Malachias, George; Anastopoulos, John (Radiology Dept., ' Sismanogleio' General Hospital, Athens (Greece))

2010-07-15

Background: Autoimmune pancreatitis (AIP) is a chronic inflammatory condition characterized by IgG4-positive plasma cells. Recent evidence suggests that it is a systemic disease affecting various organs. Tubulointerstitial nephritis has been reported in association with AIP. Purpose: To investigate the incidence and types of renal involvement in patients with AIP. Material and Methods: Eighteen patients with no history of renal disease and a diagnosis of AIP (on the basis of histopathologic findings or a combination of characteristic imaging features, increased serum IgG4 levels, and response to steroid treatment) were included. All patients underwent computed tomography (CT) imaging and follow-up ranged from 6 months to 2 years. CT images were reviewed for the presence of renal lesions. Results: Seven patients had renal involvement (38.8%). None of the lesions was visible on non-contrast-enhanced CT scan. Parenchymal lesions appeared as multiple nodules showing decreased enhancement (four cases). Pyelonephritis, lymphoma, and metastases were considered in the differential diagnosis. An ill-defined low-attenuation mass-like lesion was found in one patient, while diffuse thickening of the renal pelvis wall was evident in the last two cases. Renal lesions regressed in all patients after steroid treatment, the larger one leaving a fibrous cortical scar. Conclusion: Different types of renal lesions in patients with AIP are relatively common, appearing as multiple nodules with decreased enhancement. These findings support the proposed concept of an IgG4-related systemic disease. Autoimmune disease should be suspected in cases of renal involvement in association with pancreatic focal or diffuse enlargement.

Glucocorticoids Inhibit Basal and Hormone-Induced Serotonin Synthesis in Pancreatic Beta Cells.

Directory of Open Access Journals (Sweden)

Moina Hasni Ebou

Full Text Available Diabetes is a major complication of chronic Glucocorticoids (GCs treatment. GCs induce insulin resistance and also inhibit insulin secretion from pancreatic beta cells. Yet, a full understanding of this negative regulation remains to be deciphered. In the present study, we investigated whether GCs could inhibit serotonin synthesis in beta cell since this neurotransmitter has been shown to be involved in the regulation of insulin secretion. To this aim, serotonin synthesis was evaluated in vitro after treatment with GCs of either islets from CD1 mice or MIN6 cells, a beta-cell line. We also explored the effect of GCs on the stimulation of serotonin synthesis by several hormones such as prolactin and GLP 1. We finally studied this regulation in islet in two in vivo models: mice treated with GCs and with liraglutide, a GLP1 analog, and mice deleted for the glucocorticoid receptor in the pancreas. We showed in isolated islets and MIN6 cells that GCs decreased expression and activity of the two key enzymes of serotonin synthesis, Tryptophan Hydroxylase 1 (Tph1 and 2 (Tph2, leading to reduced serotonin contents. GCs also blocked the induction of serotonin synthesis by prolactin or by a previously unknown serotonin activator, the GLP-1 analog exendin-4. In vivo, activation of the Glucagon-like-Peptide-1 receptor with liraglutide during 4 weeks increased islet serotonin contents and GCs treatment prevented this increase. Finally, islets from mice deleted for the GR in the pancreas displayed an increased expression of Tph1 and Tph2 and a strong increased serotonin content per islet. In conclusion, our results demonstrate an original inhibition of serotonin synthesis by GCs, both in basal condition and after stimulation by prolactin or activators of the GLP-1 receptor. This regulation may contribute to the deleterious effects of GCs on beta cells.

Diffusion-weighted magnetic resonance imaging in autoimmune pancreatitis

International Nuclear Information System (INIS)

Taniguchi, Takao; Kobayashi, Hisato; Nishikawa, Koji; Iida, Etsushi; Michigami, Yoshihiro; Morimoto, Emiko; Yamashita, Rikiya; Miyagi, Ken; Okamoto, Motozumi

2009-01-01

The aim of this study was to investigate the usefulness of diffusion-weighted magnetic resonance imaging (DWI MRI) for the diagnosis and evaluation of autoimmune pancreatitis (AIP). A total of 4 consecutive patients with AIP, 5 patients with chronic alcoholic pancreatitis (CP), and 13 patients without pancreatic disease (controls) were studied. DWI was performed in the axial plane with spin-echo echo-planar imaging single-shot sequence. Apparent diffusion coefficients (ADCs) were measured in circular regions of interest in the pancreas. In AIP patients, abdominal MRI was performed before, and 2-4 weeks after steroid treatment. Follow-up study was performed chronologically for up to 11 months in two patients. The correlation between ADCs of the pancreas and the immunoglobulin G4 (IgG4) index (serum IgG4 value/serum IgG4 value before steroid treatment) was evaluated. In the AIP patients, DWI of the pancreas showed high signal intensity, and the ADCs of the pancreas (mean±standard deviation (SD): 0.97±0.18 x 10 -3 mm 2 /s) were significantly lower than those in patients with CP (1.45±0.10 x 10 -3 mm 2 /s) or the controls (1.45±0.16 x 10 -3 mm 2 /s) (Mann-Whitney U-test, P s =-0.80, P<0.05). Autoimmune pancreatitis showed high signal intensity on DWI, which improved after steroid treatment. ADCs reflected disease activity. Thus, diffusion-weighted MRI might be useful for diagnosing AIP, determining the affected area, and evaluating the effect of treatment. (author)

Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass

Directory of Open Access Journals (Sweden)

Vivas Yurena

2011-12-01

Full Text Available Abstract Background The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Results Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Conclusions Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.

Immunoglobulin G4-related disease: autoimmune pancreatitis and extrapancreatic manifestations

Directory of Open Access Journals (Sweden)

Daniel Alvarenga Fernandes

2016-04-01

Full Text Available Abstract We present a case of immunoglobulin G4 (IgG4-related disease with pancreatic and extrapancreatic involvement, including the biliary and renal systems. Given the importance of imaging methods for the diagnosis of IgG4-related disease and its differentiation from pancreatic adenocarcinoma, we emphasize important abdominal computed tomography and magnetic resonance imaging findings related to this recently recognized systemic autoimmune disease.

Effects of methyl mercury exposure on pancreatic beta cell development and function.

Science.gov (United States)

Schumacher, Lauren; Abbott, Louise C

2017-01-01

Methyl mercury is an environmental contaminant of worldwide concern. Since the discovery of methyl mercury exposure due to eating contaminated fish as the underlying cause of the Minamata disaster, the scientific community has known about the sensitivity of the developing central nervous system to mercury toxicity. Warnings are given to pregnant women and young children to limit consumption of foods containing methyl mercury to protect the embryonic, fetal and postnatally developing central nervous system. However, evidence also suggests that exposure to methyl mercury or various forms of inorganic mercury may also affect development and function of other organs. Numerous reports indicate a worldwide increase in diabetes, particularly type 2 diabetes. Quite recently, methyl mercury has been shown to have adverse effects on pancreatic beta (β) cell development and function, resulting in insulin resistance and hyperglycemia and may even lead to the development of diabetes. This review discusses possible mechanisms by which methyl mercury exposure may adversely affect pancreatic β cell development and function, and the role that methyl mercury exposure may have in the reported worldwide increase in diabetes, particularly type 2 diabetes. While additional information is needed regarding associations between mercury exposure and specific mechanisms of the pathogenesis of diabetes in the human population, methyl mercury's adverse effects on the body's natural sources of antioxidants suggest that one possible therapeutic strategy could involve supplementation with antioxidants. Thus, it is important that additional investigation be undertaken into the role of methyl mercury exposure and reduced pancreatic β cell function. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Diagnostic Dilemma in a Patient with Jaundice: How to Differentiate between Autoimmune Pancreatitis, Primary Sclerosing Cholangitis and Pancreas Carcinoma

Directory of Open Access Journals (Sweden)

Matthias Buechter

2012-04-01

Full Text Available A 68-year-old male patient was referred to our institution in May 2011 for a suspected tumor in the pancreatic head with consecutive jaundice. Using magnetic resonance imaging, further differentiation between chronic inflammation and a malignant process was not possible with certainty. Apart from cholestasis, laboratory studies showed increased values for CA 19-9 to 532 U/ml (normal <37 U/ml and hypergammaglobulinemia (immunoglobulin G, IgG of 19.3% (normal 8.0–15.8% with an elevation of the IgG4 subtype to 2,350 mg/l (normal 52–1,250 mg/l. Endoscopic retrograde cholangiopancreatography revealed a prominent stenosis of the distal ductus hepaticus communis caused by pancreatic head swelling and also a bihilar stenosis of the main hepatic bile ducts. Cytology demonstrated inflammatory cells without evidence of malignancy. Under suspicion of autoimmune pancreatitis with IgG4-associated cholangitis, immunosuppressive therapy with steroids and azathioprine was started. Follow-up endoscopic retrograde cholangiopancreatography after 3 months displayed regressive development of the diverse stenoses. Jaundice had disappeared and blood values had returned to normal ranges. Moreover, no tumor of the pancreatic head was present in the magnetic resonance control images. Due to clinical and radiological similarities but a consecutive completely different prognosis and therapy, it is of fundamental importance to differentiate between pancreatic cancer and autoimmune pancreatitis. Especially, determination of serum IgG4 levels and associated bile duct lesions induced by inflammation should clarify the diagnosis of autoimmune pancreatitis and legitimate immunosuppressive therapy.

Calcium Co-regulates Oxidative Metabolism and ATP Synthase-dependent Respiration in Pancreatic Beta Cells

Science.gov (United States)

De Marchi, Umberto; Thevenet, Jonathan; Hermant, Aurelie; Dioum, Elhadji; Wiederkehr, Andreas

2014-01-01

Mitochondrial energy metabolism is essential for glucose-induced calcium signaling and, therefore, insulin granule exocytosis in pancreatic beta cells. Calcium signals are sensed by mitochondria acting in concert with mitochondrial substrates for the full activation of the organelle. Here we have studied glucose-induced calcium signaling and energy metabolism in INS-1E insulinoma cells and human islet beta cells. In insulin secreting cells a surprisingly large fraction of total respiration under resting conditions is ATP synthase-independent. We observe that ATP synthase-dependent respiration is markedly increased after glucose stimulation. Glucose also causes a very rapid elevation of oxidative metabolism as was followed by NAD(P)H autofluorescence. However, neither the rate of the glucose-induced increase nor the new steady-state NAD(P)H levels are significantly affected by calcium. Our findings challenge the current view, which has focused mainly on calcium-sensitive dehydrogenases as the target for the activation of mitochondrial energy metabolism. We propose a model of tight calcium-dependent regulation of oxidative metabolism and ATP synthase-dependent respiration in beta cell mitochondria. Coordinated activation of matrix dehydrogenases and respiratory chain activity by calcium allows the respiratory rate to change severalfold with only small or no alterations of the NAD(P)H/NAD(P)+ ratio. PMID:24554722

Ins1 Cre knock-in mice for beta cell-specific gene recombination

OpenAIRE

Thorens Bernard; Tarussio David; Maestro Miguel Angel; Maestro Miguel Angel; Rovira Meritxell; Rovira Meritxell; Heikkilä Eija; Ferrer Jorge; Ferrer Jorge; Ferrer Jorge

2013-01-01

Aims/hypothesis Pancreatic beta cells play a central role in the control of glucose homeostasis by secreting insulin to stimulate glucose uptake by peripheral tissues. Understanding the molecular mechanisms that control beta cell function and plasticity has critical implications for the pathophysiology and therapy of major forms of diabetes. Selective gene inactivation in pancreatic beta cells, using the Cre-lox system, is a powerful approach to assess the role of particular genes in beta cel...

Autoimmune pancreatitis: An illustrated guide to diagnosis

International Nuclear Information System (INIS)

Proctor, R.D.; Rofe, C.J.; Bryant, T.J.C.; Hacking, C.N.; Stedman, B.

2013-01-01

Autoimmune pancreatitis (AIP) remains one of the rarer forms of pancreatitis but has become increasingly well recognized and widely diagnosed as it is an important differential, particularly due to the dramatic response to appropriate therapy. It is now best considered as part of a multisystem disease and the notion of “IgG4-related systemic sclerosing disease” has become widely recognized as the number of extra-pancreatic associations of AIP grows. More recently AIP has been classified into two subtypes: lymphoplasmacytic sclerosing pancreatitis (LPSP) and idiopathic duct-centric pancreatitis (IDCP) with distinct geographical, age and sex distributions for the two subtypes, in addition to different pathological characteristics. The role of imaging is crucial in AIP and should be considered in conjunction with clinical, serological, and histopathological findings to make the diagnosis. Radiologists are uniquely placed to raise the possibility of AIP and aid the exclusion of significant differentials to allow the initiation of appropriate management and avoidance of unnecessary intervention. Radiological investigation may reveal a number of characteristic imaging findings in AIP but appearances can vary considerably and the focal form of AIP may appear as a pancreatic mass, imitating pancreatic carcinoma. This review will illustrate typical and atypical appearances of AIP on all imaging modes. Emphasis will be placed on the imaging features that are likely to prove useful in discriminating AIP from other causes prior to histopathological confirmation. In addition, examples of relevant differential diagnoses are discussed and illustrated

Glucagon-like peptide-1 counteracts the detrimental effects of Advanced Glycation End-Products in the pancreatic beta cell line HIT-T 15

International Nuclear Information System (INIS)

Puddu, A.; Storace, D.; Durante, A.; Odetti, P.; Viviani, G.L.

2010-01-01

Research highlights: → GLP-1 prevents AGEs-induced cell death. → GLP-1 prevents AGEs-induced oxidative stress. → GLP-1 ameliorated AGEs-induced cell dysfunction. → GLP-1 attenuates AGEs-induced RAGE increment. → GLP-1 counteracts AGEs-induced pancreatic cell death and dysfunction. -- Abstract: Advanced Glycation End-Products (AGEs), a group of compounds resulting from the non-enzymatic reaction of reducing sugars with the free amino group of proteins, are implicated in diabetic complications. We previously demonstrated that exposure of the pancreatic islet cell line HIT-T 15 to high concentrations of AGEs significantly decreases cell proliferation and insulin secretion, and affects transcription factors regulating insulin gene transcription. The glucagon-like peptide-1 (GLP-1) is an incretin hormone that increases proinsulin biosynthesis, stimulates insulin secretion, and improves pancreatic beta-cell viability. The aim of this work was to investigate the effects of GLP-1 on the function and viability of HIT-T 15 cells cultured with AGEs. HIT-T 15 cells were cultured for 5 days in presence of AGEs alone, or supplemented with 10 nmol/l GLP-1. Cell viability, insulin secretion, redox balance, and expression of the AGEs receptor (RAGE) were then determined. The results showed that GLP-1 protected beta cell against AGEs-induced cell death preventing both apoptosis and necrosis. Moreover, addition of GLP-1 to the AGEs culture medium restored the redox balance, improved the responsiveness to glucose, and attenuated AGEs-induced RAGE expression. These findings provide evidence that GLP-1 protects beta cells from the dangerous effects of AGEs.

What are the potential benefits of clinical beta-cell imaging in diabetes mellitus?

Science.gov (United States)

Göke, Burkhard

2010-05-01

Previously, studies of the endocrine pancreatic beta-cell were mainly performed ex vivo by morphological means. This data supported the analysis of pathophysiological changes in the pancreatic islet during insults such as diabetes mellitus. Metabolic testing of the pancreatic islet by assaying hormone parameters such als plasma insulin or C-peptide combined with more or less sophisticated calculations allowed conclusions about states of insulin resistance or secretory failure. It also allowed certain correlations of endocrine function with beta-cell mass. Today, with firmer pathophysiological concepts about beta-cell failure, modern protocols of islet transplantation, and drugs on the market coming with promises of preservation or even expansion of beta-cell mass in diabetes mellitus it has become very attractive to search for tools measuring beta-cell mass, if possible even repeatingly in the same organism in vivo. From a clinical point of view, the potential of pancreatic beta-cell mass imaging technologies is looked upon with high expectations. Methodologically, the decisive question is whether it is likely that future beta-cell imaging will provide significant advantages over the metabolic methods already in hand. With new in vivo tools, studies of beta-cell mass and function may offer even new approaches stratifying patients to anti-diabetic therapies.

Role of transcription factor KLF11 and its diabetes-associated gene variants in pancreatic beta cell function

Science.gov (United States)

Neve, Bernadette; Fernandez-Zapico, Martin E.; Ashkenazi-Katalan, Vered; Dina, Christian; Hamid, Yasmin H.; Joly, Erik; Vaillant, Emmanuel; Benmezroua, Yamina; Durand, Emmanuelle; Bakaher, Nicolas; Delannoy, Valerie; Vaxillaire, Martine; Cook, Tiffany; Dallinga-Thie, Geesje M.; Jansen, Hans; Charles, Marie-Aline; Clément, Karine; Galan, Pilar; Hercberg, Serge; Helbecque, Nicole; Charpentier, Guillaume; Prentki, Marc; Hansen, Torben; Pedersen, Oluf; Urrutia, Raul; Melloul, Danielle; Froguel, Philippe

2005-01-01

KLF11 (TIEG2) is a pancreas-enriched transcription factor that has elicited significant attention because of its role as negative regulator of exocrine cell growth in vitro and in vivo. However, its functional role in the endocrine pancreas remains to be established. Here, we report, for the first time, to our knowledge, the characterization of KLF11 as a glucose-inducible regulator of the insulin gene. A combination of random oligonucleotide binding, EMSA, luciferase reporter, and chromatin immunoprecipitation assays shows that KLF11 binds to the insulin promoter and regulates its activity in beta cells. Genetic analysis of the KLF11 gene revealed two rare variants (Ala347Ser and Thr220Met) that segregate with diabetes in families with early-onset type 2 diabetes, and significantly impair its transcriptional activity. In addition, analysis of 1,696 type 2 diabetes mellitus and 1,776 normoglycemic subjects show a frequent polymorphic Gln62Arg variant that significantly associates with type 2 diabetes mellitus in North European populations (OR = 1.29, P = 0.00033). Moreover, this variant alters the corepressor mSin3A-binding activity of KLF11, impairs the activation of the insulin promoter and shows lower levels of insulin expression in pancreatic beta cells. In addition, subjects carrying the Gln62Arg allele show decreased plasma insulin after an oral glucose challenge. Interestingly, all three nonsynonymous KLF11 variants show increased repression of the catalase 1 promoter, suggesting a role in free radical clearance that may render beta cells more sensitive to oxidative stress. Thus, both functional and genetic analyses reveal that KLF11 plays a role in the regulation of pancreatic beta cell physiology, and its variants may contribute to the development of diabetes. PMID:15774581

Cocoa Phenolic Extract Protects Pancreatic Beta Cells against Oxidative Stress

Directory of Open Access Journals (Sweden)

Laura Bravo

2013-07-01

Full Text Available Diabetes mellitus is associated with reductions in glutathione, supporting the critical role of oxidative stress in its pathogenesis. Antioxidant food components such as flavonoids have a protective role against oxidative stress-induced degenerative and age-related diseases. Flavonoids constitute an important part of the human diet; they can be found in most plant foods, including green tea, grapes or cocoa and possess multiple biological activities. This study investigates the chemo-protective effect of a cocoa phenolic extract (CPE containing mainly flavonoids against oxidative stress induced by tert-butylhydroperoxide (t-BOOH on Ins-1E pancreatic beta cells. Cell viability and oxidative status were evaluated. Ins-1E cells treatment with 5–20 μg/mL CPE for 20 h evoked no cell damage and did not alter ROS production. Addition of 50 μM t-BOOH for 2 h increased ROS and carbonyl groups content and decreased reduced glutathione level. Pre-treatment of cells with CPE significantly prevented the t-BOOH-induced ROS and carbonyl groups and returned antioxidant defences to adequate levels. Thus, Ins-1E cells treated with CPE showed a remarkable recovery of cell viability damaged by t-BOOH, indicating that integrity of surviving machineries in the CPE-treated cells was notably protected against the oxidative insult.

Stevioside improves pancreatic beta-cell function during glucotoxicity via regulation of acetyl-CoA carboxylase.

Science.gov (United States)

Chen, Jianguo; Jeppesen, Per Bendix; Nordentoft, Iver; Hermansen, Kjeld

2007-06-01

Chronic hyperglycemia is detrimental to pancreatic beta-cells, causing impaired insulin secretion and beta-cell turnover. The characteristic secretory defects are increased basal insulin secretion (BIS) and a selective loss of glucose-stimulated insulin secretion (GSIS). Several recent studies support the view that the acetyl-CoA carboxylase (ACC) plays a pivotal role for GSIS. We have shown that stevioside (SVS) enhances insulin secretion and ACC gene expression. Whether glucotoxicity influences ACC and whether this action can be counteracted by SVS are not known. To investigate this, we exposed isolated mouse islets as well as clonal INS-1E beta-cells for 48 h to 27 or 16.7 mM glucose, respectively. We found that 48-h exposure to high glucose impairs GSIS from mouse islets and INS-1E cells, an effect that is partly counteracted by SVS. The ACC dephosphorylation inhibitor okadaic acid (OKA, 10(-8) M), and 5-aminoimidazole-4-carboxamide-1-beta-d-ribofuranoside (AICAR, 10(-4) M), an activator of 5'-AMP protein kinase that phosphorylates ACC, eliminated the beneficial effect of SVS. 5-Tetrade-cyloxy-2-furancarboxylic acid (TOFA), the specific ACC inhibitor, blocked the effect of SVS as well. During glucotoxity, ACC gene expression, ACC protein, and phosphorylated ACC protein were increased in INS-1E beta-cells. SVS pretreatment further increased ACC gene expression with strikingly elevated ACC activity and increased glucose uptake accompanied by enhanced GSIS. Our studies show that glucose is a potent stimulator of ACC and that SVS to some extent counteracts glucotoxicity via increased ACC activity. SVS possesses the potential to alleviate negative effects of glucotoxicity in beta-cells via a unique mechanism of action.

Histone deacetylases 1 and 3 but not 2 mediate cytokine-induced beta cell apoptosis in INS-1 cells and dispersed primary islets from rats and are differentially regulated in the islets of type 1 diabetic children

DEFF Research Database (Denmark)

Lundh, M; Christensen, D P; Damgaard Nielsen, M

2012-01-01

onset, HDAC1 was upregulated in beta cells whereas HDAC2 and -3 were downregulated in comparison with five paediatric controls. CONCLUSIONS/INTERPRETATION: These data demonstrate non-redundant functions of islet class I HDACs and suggest that targeting HDAC1 and HDAC3 would provide optimal protection......AIMS/HYPOTHESIS: Histone deacetylases (HDACs) are promising pharmacological targets in cancer and autoimmune diseases. All 11 classical HDACs (HDAC1-11) are found in the pancreatic beta cell, and HDAC inhibitors (HDACi) protect beta cells from inflammatory insults. We investigated which HDACs...... of HDAC1, -2 and -3 rescued INS-1 cells from inflammatory damage. Small hairpin RNAs against HDAC1 and -3, but not HDAC2, reduced pro-inflammatory cytokine-induced beta cell apoptosis in INS-1 and primary rat islets. The protective properties of specific HDAC knock-down correlated with attenuated cytokine...

From Pathogenesis, Clinical Manifestation, and Diagnosis to Treatment: An Overview on Autoimmune Pancreatitis

Directory of Open Access Journals (Sweden)

Ou Cai

2017-01-01

Full Text Available Autoimmune pancreatitis (AIP is a special type of chronic pancreatitis which is autoimmune mediated. The international consensus diagnostic criteria (ICDC 2011 proposed two types of AIP: type I is associated with histological pattern of lymphoplasmacytic sclerosing pancreatitis (LPSP, characterized by serum IgG4 elevation, whereas type 2 is named idiopathic duct-centric pancreatitis (IDCP, with granulocytic epithelial lesion (GEL and immunoglobulin G4 (IgG4 negative. The pathogenic mechanism is unclear now; based on genetic factors, disease specific or related antigens, innate and adaptive immunity may be involved. The most common clinical manifestations of AIP are obstructive jaundice and upper abdominal pain. The diagnosis can be made by a combination of parenchymal and ductal imaging, serum IgG4 concentrations, pancreatic histology, extrapancreatic disease, and glucocorticoid responsiveness according to ICDC 2011. Because of the clinical and imaging similarities with pancreatic cancer, general work-up should be done carefully to exclude pancreatic malignant tumor before empirical trial of glucocorticoid treatment. Glucocorticoid is the most common drug for AIP to induce remission, while there still exists controversy on steroid maintenance and treatment for relapse. Further studies should be done to identify more specific serum biomarkers for AIP, the pathogenic mechanisms, and the treatment for relapse.

Successful treatment of pediatric IgG4 related systemic disease with mycophenolate mofetil: case report and a review of the pediatric autoimmune pancreatitis literature

Directory of Open Access Journals (Sweden)

Cron Randy Q

2011-01-01

Full Text Available Abstract Autoimmune pancreatitis is frequently associated with elevated serum and tissue IgG4 levels in the adult population, but there are few reports of pediatric autoimmune pancreatitis, and even fewer reports of IgG4 related systemic disease in a pediatric population. The standard of care treatment in adults is systemic corticosteroids with resolution of symptoms in most cases; however, multiple courses of corticosteroids are occasionally required and some patients require long term corticosteroids. In these instances, steroid sparing disease modify treatments are in demand. We describe a 13-year-old girl with IgG4 related systemic disease who presented with chronic recurrent autoimmune pancreatitis resulting in surgical intervention for obstructive hyperbilirubinemia and chronic corticosteroid treatment. In addition, she developed fibrosing medianstinitis as part of her IgG4 related systemic disease. She was eventually successfully treated with mycophenolate mofetil allowing for discontinuation of corticosteroids. This is the first reported use of mycophenolate mofetil for IgG4 related pancreatitis. Although autoimmune pancreatitis as part of IgG4 related systemic disease is rarely reported in pediatrics, autoimmune pancreatitis is also characterized as idiopathic fibrosing pancreatitis. All pediatric autoimmune pancreatitis cases reported in the world medical literature were identified via a PUBMED search and are reviewed herein. Twelve reports of pediatric autoimmune pancreatitis were identified, most of which were treated with corticosteroids or surgical approaches. Most case reports failed to report IgG4 levels, so it remains unclear how commonly IgG4 related autoimmune pancreatitis occurs during childhood. Increased evaluation of IgG4 levels in patients with autoimmune pancreatitis may shed further light on the association of IgG4 with pancreatitis and the underlying pathophysiology.

Type 1 diabetes and polyglandular autoimmune syndrome: A review

Science.gov (United States)

Hansen, Martin P; Matheis, Nina; Kahaly, George J

2015-01-01

Type 1 diabetes (T1D) is an autoimmune disorder caused by inflammatory destruction of the pancreatic tissue. The etiopathogenesis and characteristics of the pathologic process of pancreatic destruction are well described. In addition, the putative susceptibility genes for T1D as a monoglandular disease and the relation to polyglandular autoimmune syndrome (PAS) have also been well explored. The incidence of T1D has steadily increased in most parts of the world, especially in industrialized nations. T1D is frequently associated with autoimmune endocrine and non-endocrine diseases and patients with T1D are at a higher risk for developing several glandular autoimmune diseases. Familial clustering is observed, which suggests that there is a genetic predisposition. Various hypotheses pertaining to viral- and bacterial-induced pancreatic autoimmunity have been proposed, however a definitive delineation of the autoimmune pathomechanism is still lacking. In patients with PAS, pancreatic and endocrine autoantigens either colocalize on one antigen-presenting cell or are expressed on two/various target cells sharing a common amino acid, which facilitates binding to and activation of T cells. The most prevalent PAS phenotype is the adult type 3 variant or PAS type III, which encompasses T1D and autoimmune thyroid disease. This review discusses the findings of recent studies showing noticeable differences in the genetic background and clinical phenotype of T1D either as an isolated autoimmune endocrinopathy or within the scope of polyglandular autoimmune syndrome. PMID:25685279

PED/PEA-15 inhibits hydrogen peroxide-induced apoptosis in Ins-1E pancreatic beta-cells via PLD-1.

Directory of Open Access Journals (Sweden)

Francesca Fiory

Full Text Available The small scaffold protein PED/PEA-15 is involved in several different physiologic and pathologic processes, such as cell proliferation and survival, diabetes and cancer. PED/PEA-15 exerts an anti-apoptotic function due to its ability to interfere with both extrinsic and intrinsic apoptotic pathways in different cell types. Recent evidence shows that mice overexpressing PED/PEA-15 present larger pancreatic islets and increased beta-cells mass. In the present work we investigated PED/PEA-15 role in hydrogen peroxide-induced apoptosis in Ins-1E beta-cells. In pancreatic islets isolated from Tg(PED/PEA-15 mice hydrogen peroxide-induced DNA fragmentation was lower compared to WT islets. TUNEL analysis showed that PED/PEA-15 overexpression increases the viability of Ins-1E beta-cells and enhances their resistance to apoptosis induced by hydrogen peroxide exposure. The activity of caspase-3 and the cleavage of PARP-1 were markedly reduced in Ins-1E cells overexpressing PED/PEA-15 (Ins-1E(PED/PEA-15. In parallel, we observed a decrease of the mRNA levels of pro-apoptotic genes Bcl-xS and Bad. In contrast, the expression of the anti-apoptotic gene Bcl-xL was enhanced. Accordingly, DNA fragmentation was higher in control cells compared to Ins-1E(PED/PEA-15 cells. Interestingly, the preincubation with propranolol, an inhibitor of the pathway of PLD-1, a known interactor of PED/PEA-15, responsible for its deleterious effects on glucose tolerance, abolishes the antiapoptotic effects of PED/PEA-15 overexpression in Ins-1E beta-cells. The same results have been obtained by inhibiting PED/PEA-15 interaction with PLD-1 in Ins-1E(PED/PEA-15. These results show that PED/PEA-15 overexpression is sufficient to block hydrogen peroxide-induced apoptosis in Ins-1E cells through a PLD-1 mediated mechanism.

Characterization of the distal promoter of the human pyruvate carboxylase gene in pancreatic beta cells.

Directory of Open Access Journals (Sweden)

Ansaya Thonpho

Full Text Available Pyruvate carboxylase (PC is an enzyme that plays a crucial role in many biosynthetic pathways in various tissues including glucose-stimulated insulin secretion. In the present study, we identify promoter usage of the human PC gene in pancreatic beta cells. The data show that in the human, two alternative promoters, proximal and distal, are responsible for the production of multiple mRNA isoforms as in the rat and mouse. RT-PCR analysis performed with cDNA prepared from human liver and islets showed that the distal promoter, but not the proximal promoter, of the human PC gene is active in pancreatic beta cells. A 1108 bp fragment of the human PC distal promoter was cloned and analyzed. It contains no TATA box but possesses two CCAAT boxes, and other putative transcription factor binding sites, similar to those of the distal promoter of rat PC gene. To localize the positive regulatory region in the human PC distal promoter, 5'-truncated and the 25-bp and 15-bp internal deletion mutants of the human PC distal promoter were generated and used in transient transfections in INS-1 832/13 insulinoma and HEK293T (kidney cell lines. The results indicated that positions -340 to -315 of the human PC distal promoter serve as (an activator element(s for cell-specific transcription factor, while the CCAAT box at -71/-67, a binding site for nuclear factor Y (NF-Y, as well as a GC box at -54/-39 of the human PC distal promoter act as activator sequences for basal transcription.

Are genetic variants in the platelet-derived growth factor [beta] gene associated with chronic pancreatitis?

Science.gov (United States)

Muddana, Venkata; Park, James; Lamb, Janette; Yadav, Dhiraj; Papachristou, Georgios I; Hawes, Robert H; Brand, Randall; Slivka, Adam; Whitcomb, David C

2010-11-01

Platelet-derived growth factor [beta] (PDGF-[beta]) is a major signal in proliferation and matrix synthesis through activated pancreatic stellate cells, leading to fibrosis of the pancreas. Recurrent acute pancreatitis (RAP) seems to predispose to chronic pancreatitis (CP) in some patients but not others. We tested the hypothesis that 2 known PDGF-[beta] polymorphisms are associated with progression from RAP to CP. We also tested the hypothesis that PDGF-[beta] polymorphisms in combination with environmental risk factors such as alcohol and smoking are associated with CP. Three hundred eighty-two patients with CP (n = 176) and RAP (n = 206) and 251 controls were evaluated. Platelet-derived growth factor [beta] polymorphisms +286 A/G (rs#1800818) seen in 5'-UTR and +1135 A/C (rs#1800817) in first intron were genotyped using single-nucleotide polymorphism polymerase chain reaction approach and confirmed by DNA sequencing. The genotypic frequencies for PDGF-[beta] polymorphisms in positions +286 and +1135 were found to be similar in controls and patients with RAP and CP. There was no difference in genotypic frequencies among RAP, CP, and controls in subjects in the alcohol and smoking subgroups. Known variations in the PDGF-[beta] gene do not have a significant effect on promoting or preventing fibrogenesis in pancreatitis. Further evaluation of this important pathway is warranted.

Activation of PPAR{delta} up-regulates fatty acid oxidation and energy uncoupling genes of mitochondria and reduces palmitate-induced apoptosis in pancreatic {beta}-cells

Energy Technology Data Exchange (ETDEWEB)

Wan, Jun; Jiang, Li; Lue, Qingguo; Ke, Linqiu [Department of Endocrinology, West China Hospital of Sichuan University, 37 Guoxue Lane, Chengdu, Sichuan 610041 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, Sichuan University, No. 14, 3rd Section, Renmin South Road, Chengdu, Sichuan 610041 (China); Tong, Nanwei, E-mail: buddyjun@hotmail.com [Department of Endocrinology, West China Hospital of Sichuan University, 37 Guoxue Lane, Chengdu, Sichuan 610041 (China)

2010-01-15

Recent evidence indicates that decreased oxidative capacity, lipotoxicity, and mitochondrial aberrations contribute to the development of insulin resistance and type 2 diabetes. The goal of this study was to investigate the effects of peroxisome proliferator-activated receptor {delta} (PPAR{delta}) activation on lipid oxidation, mitochondrial function, and insulin secretion in pancreatic {beta}-cells. After HIT-T15 cells (a {beta}-cell line) were exposed to high concentrations of palmitate and GW501516 (GW; a selective agonist of PPAR{delta}), we found that administration of GW increased the expression of PPAR{delta} mRNA. GW-induced activation of PPAR{delta} up-regulated carnitine palmitoyltransferase 1 (CPT1), long-chain acyl-CoA dehydrogenase (LCAD), pyruvate dehydrogenase kinase 4 (PDK4), and uncoupling protein 2 (UCP2); alleviated mitochondrial swelling; attenuated apoptosis; and reduced basal insulin secretion induced by increased palmitate in HIT cells. These results suggest that activation of PPAR{delta} plays an important role in protecting pancreatic {beta}-cells against aberrations caused by lipotoxicity in metabolic syndrome and diabetes.

Enrichment of putative pancreatic progenitor cells from mice by sorting for prominin1 (CD133) and platelet-derived growth factor receptor beta.

Science.gov (United States)

Hori, Yuichi; Fukumoto, Miki; Kuroda, Yoshikazu

2008-11-01

Success in islet transplantation-based therapies for type 1 diabetes mellitus and an extreme shortage of pancreatic islets have motivated recent efforts to develop renewable sources of islet-replacement tissue. Although pancreatic progenitor cells hold a promising potential, only a few attempts have been made at the prospective isolation of pancreatic stem/progenitor cells, because of the lack of specific markers and the development of effective cell culture methods. We found that prominin1 (also known as CD133) recognized the undifferentiated epithelial cells, whereas platelet-derived growth factor receptor beta (PDGFRbeta) was expressed on the mesenchymal cells in the mouse embryonic pancreas. We then developed an isolation method for putative stem/progenitor cells by flow cytometric cell sorting and characterized their potential for differentiation to pancreatic tissue using both in vitro and in vivo protocols. Flow cytometry and the subsequent reverse transcription-polymerase chain reaction and microarray analysis revealed pancreatic epithelial progenitor cells to be highly enriched in the prominin1(high)PDGFRbeta(-) cell population. During in vivo differentiation, these cell populations were able to differentiate into endocrine, exocrine, and ductal tissues, including the formation of an insulin-producing cell cluster. We established the prospective isolation of putative pancreatic epithelial progenitor cells by sorting for prominin1 and PDGFRbeta. Since this strategy is based on the cell surface markers common to human and rodents, these findings may lead to the development of new strategies to derive transplantable islet-replacement tissues from human pancreatic stem/progenitor cells. Disclosure of potential conflicts of interest is found at the end of this article.

Production of pancreatic hormone-expressing endocrine cells from human embryonic stem cells.

Science.gov (United States)

D'Amour, Kevin A; Bang, Anne G; Eliazer, Susan; Kelly, Olivia G; Agulnick, Alan D; Smart, Nora G; Moorman, Mark A; Kroon, Evert; Carpenter, Melissa K; Baetge, Emmanuel E

2006-11-01

Of paramount importance for the development of cell therapies to treat diabetes is the production of sufficient numbers of pancreatic endocrine cells that function similarly to primary islets. We have developed a differentiation process that converts human embryonic stem (hES) cells to endocrine cells capable of synthesizing the pancreatic hormones insulin, glucagon, somatostatin, pancreatic polypeptide and ghrelin. This process mimics in vivo pancreatic organogenesis by directing cells through stages resembling definitive endoderm, gut-tube endoderm, pancreatic endoderm and endocrine precursor--en route to cells that express endocrine hormones. The hES cell-derived insulin-expressing cells have an insulin content approaching that of adult islets. Similar to fetal beta-cells, they release C-peptide in response to multiple secretory stimuli, but only minimally to glucose. Production of these hES cell-derived endocrine cells may represent a critical step in the development of a renewable source of cells for diabetes cell therapy.

AAV-mediated pancreatic overexpression of Igf1 counteracts progression to autoimmune diabetes in mice.

Science.gov (United States)

Mallol, Cristina; Casana, Estefania; Jimenez, Veronica; Casellas, Alba; Haurigot, Virginia; Jambrina, Claudia; Sacristan, Victor; Morró, Meritxell; Agudo, Judith; Vilà, Laia; Bosch, Fatima

2017-07-01

Type 1 diabetes is characterized by autoimmune destruction of β-cells leading to severe insulin deficiency. Although many improvements have been made in recent years, exogenous insulin therapy is still imperfect; new therapeutic approaches, focusing on preserving/expanding β-cell mass and/or blocking the autoimmune process that destroys islets, should be developed. The main objective of this work was to test in non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, the effects of local expression of Insulin-like growth factor 1 (IGF1), a potent mitogenic and pro-survival factor for β-cells with immunomodulatory properties. Transgenic NOD mice overexpressing IGF1 specifically in β-cells (NOD-IGF1) were generated and phenotyped. In addition, miRT-containing, IGF1-encoding adeno-associated viruses (AAV) of serotype 8 (AAV8-IGF1-dmiRT) were produced and administered to 4- or 11-week-old non-transgenic NOD females through intraductal delivery. Several histological, immunological, and metabolic parameters were measured to monitor disease over a period of 28-30 weeks. In transgenic mice, local IGF1 expression led to long-term suppression of diabetes onset and robust protection of β-cell mass from the autoimmune insult. AAV-mediated pancreatic-specific overexpression of IGF1 in adult animals also dramatically reduced diabetes incidence, both when vectors were delivered before pathology onset or once insulitis was established. Transgenic NOD-IGF1 and AAV8-IGF1-dmiRT-treated NOD animals had much less islet infiltration than controls, preserved β-cell mass, and normal insulinemia. Transgenic and AAV-treated islets showed less expression of antigen-presenting molecules, inflammatory cytokines, and chemokines important for tissue-specific homing of effector T cells, suggesting IGF1 modulated islet autoimmunity in NOD mice. Local expression of Igf1 by AAV-mediated gene transfer counteracts progression to diabetes in NOD mice. This study suggests a

Pancreatic duct abnormalities in focal autoimmune pancreatitis: MR/MRCP imaging findings

Energy Technology Data Exchange (ETDEWEB)

Negrelli, Riccardo; Manfredi, Riccardo; Pedrinolla, Beatrice; Boninsegna, Enrico; Ventriglia, Anna; Mehrabi, Sara; Pozzi Mucelli, Roberto [G.B. Rossi University Hospital, University of Verona, Department of Radiology, Verona (Italy); Frulloni, Luca [Universita di Verona, Department of Gastroenterology, Policlinico G.B. Rossi, Verona (Italy)

2014-08-09

To evaluate the magnetic resonance (MR) imaging-MR cholangiopancreatographic (MRCP) findings of focal forms of autoimmune pancreatitis (AIP) to describe ductal involvement at diagnosis. MR examinations of 123 patients affected by AIP were analysed. We included 26 patients who satisfied International Consensus Diagnostic Criteria and were suffering from focal AIP. Image analysis included: site of parenchymal enlargement, main pancreatic duct (MPD) diameter, MPD stenosis, stricture length, presence of upstream dilation within the stricture, signal intensity, and pancreatic enhancement. Signal intensity abnormalities were localized in the head in 10/26 (38.5 %) and in the body-tail in 16/26 (61.5 %) patients. MRCP showed a single MPD stenosis in 12/26 (46.1 %) and multiple MPD stenosis in 14/26 (53.8 %) patients, without a dilation of the upstream MPD (mean: 3.83 mm). Lesions showed hypointensity on T1-weighted images in all patients, and hyperintensity on T2-weighted images in 22/26 (84.6 %) patients. The affected parenchyma was hypovascular during the arterial phase in 25/26 (96.2 %) patients with contrast retention. MR-MRCP are effective techniques for the diagnosis of AIP showing the loss of the physiological lobulation and the typical contrastographic appearance. The presence of multiple, long stenoses without an upstream MPD dilation at MRCP suggests the diagnosis of AIP, and can be useful in differential diagnosis of pancreatic adenocarcinoma. (orig.)

IL-8 Expression in Granulocytic Epithelial Lesions of Idiopathic Duct-centric Pancreatitis (Type 2 Autoimmune Pancreatitis).

Science.gov (United States)

Ku, Yuna; Hong, Seung-Mo; Fujikura, Kohei; Kim, Sung Joo; Akita, Masayuki; Abe-Suzuki, Shiho; Shiomi, Hideyuki; Masuda, Atsuhiro; Itoh, Tomoo; Azuma, Takeshi; Kim, Myung-Hwan; Zen, Yoh

2017-08-01

Type 2 autoimmune pancreatitis (type 2 AIP) develops in isolation or sometimes in association with ulcerative colitis. Its diagnosis requires the histologic confirmation of granulocytic epithelial lesions (GELs) with no diagnostic biomarker currently available. This study aimed to elucidate the tissue expression of cytokines and their diagnostic value in this condition. In quantitative polymerase chain reaction for multiple cytokines using tissue-derived mRNA, the expression level of interleukin (IL)-8 was markedly higher in type 2 AIP than in type 1 AIP (Ppancreatitis adjacent to pancreatic cancers (peritumoral pancreatitis) exhibited IL-8 expression in the epithelium (3/12; 25%) and inflammatory cells (10/12; 83%), expression levels were significantly lower than those in type 2 AIP (Ppancreatitis with 92% sensitivity and 92% to 100% specificity. Furthermore, CD3/IL-8-coexpressing lymphocytes were almost restricted to type 2 AIP. Interestingly, a similar pattern of IL-8 expression was also observed in colonic biopsies of ulcerative colitis. In conclusion, the overexpression of IL-8 may underlie the development of GELs in type 2 AIP, and IL-8 immunostaining or IL-8/CD3 double staining may become an ancillary method for its diagnosis. The similar expression pattern of IL-8 in ulcerative colitis also suggests a pathogenetic link between the 2 conditions.

Progenitor potential of nkx6.1-expressing cells throughout zebrafish life and during beta cell regeneration.

Science.gov (United States)

Ghaye, Aurélie P; Bergemann, David; Tarifeño-Saldivia, Estefania; Flasse, Lydie C; Von Berg, Virginie; Peers, Bernard; Voz, Marianne L; Manfroid, Isabelle

2015-09-02

In contrast to mammals, the zebrafish has the remarkable capacity to regenerate its pancreatic beta cells very efficiently. Understanding the mechanisms of regeneration in the zebrafish and the differences with mammals will be fundamental to discovering molecules able to stimulate the regeneration process in mammals. To identify the pancreatic cells able to give rise to new beta cells in the zebrafish, we generated new transgenic lines allowing the tracing of multipotent pancreatic progenitors and endocrine precursors. Using novel bacterial artificial chromosome transgenic nkx6.1 and ascl1b reporter lines, we established that nkx6.1-positive cells give rise to all the pancreatic cell types and ascl1b-positive cells give rise to all the endocrine cell types in the zebrafish embryo. These two genes are initially co-expressed in the pancreatic primordium and their domains segregate, not as a result of mutual repression, but through the opposite effects of Notch signaling, maintaining nkx6.1 expression while repressing ascl1b in progenitors. In the adult zebrafish, nkx6.1 expression persists exclusively in the ductal tree at the tip of which its expression coincides with Notch active signaling in centroacinar/terminal end duct cells. Tracing these cells reveals that they are able to differentiate into other ductal cells and into insulin-expressing cells in normal (non-diabetic) animals. This capacity of ductal cells to generate endocrine cells is supported by the detection of ascl1b in the nkx6.1:GFP ductal cell transcriptome. This transcriptome also reveals, besides actors of the Notch and Wnt pathways, several novel markers such as id2a. Finally, we show that beta cell ablation in the adult zebrafish triggers proliferation of ductal cells and their differentiation into insulin-expressing cells. We have shown that, in the zebrafish embryo, nkx6.1+ cells are bona fide multipotent pancreatic progenitors, while ascl1b+ cells represent committed endocrine precursors. In

Risk factors for pancreatic stone formation in autoimmune pancreatitis over a long-term course.

Science.gov (United States)

Maruyama, Masahiro; Arakura, Norikazu; Ozaki, Yayoi; Watanabe, Takayuki; Ito, Tetsuya; Yoneda, Suguru; Maruyama, Masafumi; Muraki, Takashi; Hamano, Hideaki; Matsumoto, Akihiro; Kawa, Shigeyuki

2012-05-01

Autoimmune pancreatitis (AIP) has the potential to progress to a chronic state that forms pancreatic stones. The aim of this study was to clarify the risk factors underlying pancreatic stone formation in AIP. Sixty-nine patients with AIP who had been followed for at least 3 years were enrolled for evaluation of clinical and laboratory factors as well as computed tomography and endoscopic retrograde cholangiopancreatography findings. During the course of this study, increased or de novo stone formation was seen in 28 patients, who were defined as the stone-forming group. No stones were observed in 32 patients, who were defined as the non-stone-forming group. Nine patients who had stones at diagnosis but showed no change during the course of this study were excluded from our cohort. Univariate analysis revealed no significant differences in clinical or laboratory factors associated with AIP-specific inflammation between the two groups. However, pancreatic head swelling (P = 0.006) and narrowing of both Wirsung's and Santorini's ducts in the pancreatic head region (P = 0.010) were significantly more frequent in the stone-forming group. Furthermore, multivariate analysis identified Wirsung and Santorini duct narrowing at diagnosis as a significant independent risk factor for pancreatic stone formation (OR 4.4, P = 0.019). A primary risk factor for pancreatic stone formation in AIP was narrowing of both Wirsung's and Santorini's ducts, which most presumably led to pancreatic juice stasis and stone development.

A Patient with Autoimmune Pancreatitis Type 1 with Previously Known Lymphadenopathy, Both in the Context of IgG4-related Disease

OpenAIRE

Alidjan, Fazil M.; Karim, Faiz; Verdijk, Rob M.; van Esser, Joost W.; van Heerde, Marianne J.

2015-01-01

Patient: Male, 62 Final Diagnosis: Auto-immune pancreatitis Symptoms: Jaundice ? lymfadenopathy Medication: ? Clinical Procedure: Laboratory ? imaging Specialty: Gastroenterology and Hepatology Objective: Unusual clinical course Background: Autoimmune pancreatitis (AIP) is an important clinical pathologic concept of IgG-4-related disease. AIP is a rare cause of chronic pancreatitis, characterized by a fibroinflammatory process by lymphoplasmacytic infiltrates, storiform fibrosis, obliterative...

Differentiation between autoimmune pancreatitis and pancreatic carcinoma based on endoscopic retrograde cholangiopancreatography findings

International Nuclear Information System (INIS)

Nishino, Takayoshi; Oyama, Hiroyasu; Shiratori, Keiko; Toki, Fumitake

2010-01-01

We have reviewed the endoscopic retrograde cholangiopancreatography (ERCP) images of patients with autoimmune pancreatitis (AIP) and pancreatic carcinoma (Pca) in an attempt to identify findings that would facilitate making a differential diagnosis between AIP and Pca. The study cohort consisted of 39 patients diagnosed with AIP and 62 patients diagnosed with Pca. The ERCP findings in the pancreatic duct and biliary tract were compared between the two groups. The ERCP images revealed that AIP patients had a higher prevalence of narrowing of the main pancreatic duct (MPD) for ≥3 cm of its length and a higher prevalence for the presence of side branches in the narrowed portion of the MPD than Pca patients (p 5 cm of its length and the presence of side branches. Among our patient cohort, the ERCP findings in terms of the length of the narrowed portion of the MPD, the presence of side branches, and maximal diameter of the upstream MPD enabled differential diagnosis between AIP and Pca in most of the cases. However, it must be borne in mind that some Pca patients have ERCP findings similar to those of AIP patients. (author)

Exocrine and endocrine pancreatic function in 21 patients suffering from autoimmune pancreatitis before and after steroid treatment.

Science.gov (United States)

Frulloni, Luca; Scattolini, Chiara; Katsotourchi, Anna Maria; Amodio, Antonio; Gabbrielli, Armando; Zamboni, Giuseppe; Benini, Luigi; Vantini, Italo

2010-01-01

Autoimmune pancreatitis (AIP) responds rapidly and dramatically to steroid therapy. The aim of this study was to evaluate pancreatic exocrine and endocrine function in patients suffering from AIP both before and after steroid therapy. Fecal elastase 1 and diabetes were evaluated before steroid therapy and within 1 month of its suspension in 21 patients (13 males and 8 females, mean age 43 +/- 16.5 years) diagnosed as having AIP between 2006 and 2008. At clinical onset, fecal elastase 1 was 107 +/- 126 microg/g stool. Thirteen patients (62%) showed severe pancreatic insufficiency (insufficiency (100-200 microg/g stool), while 4 (19%) had normal pancreatic function (>200 microg/g stool). Before steroids, diabetes was diagnosed in 5 patients (24%), all of whom had very low levels of fecal elastase 1 (endocrine pancreatic insufficiency at clinical onset. These insufficiencies improve after steroid therapy. Copyright 2010 S. Karger AG, Basel.

Diabetic Hyperglycemia: Link to Impaired Glucose Transport in Pancreatic β Cells

Science.gov (United States)

Unger, Roger H.

1991-03-01

Glucose uptake into pancreatic β cells by means of the glucose transporter GLUT-2, which has a high Michaelis constant, is essential for the normal insulin secretory response to hyperglycemia. In both autoimmune and nonautoimmune diabetes, this glucose transport is reduced as a consequence of down-regulation of the normal β-cell transporter. In autoimmune diabetes, circulating immunoglobulins can further impair this glucose transport by inhibiting functionally intact transporters. Insights into mechanisms of the unresponsiveness of β cells to hyperglycemia may improve the management and prevention of diabetes.

Mechanisms of pancreatic beta-cell growth and regeneration

DEFF Research Database (Denmark)

Nielsen, Jens Høiriis

1989-01-01

Information about the mechanism of beta-cell growth and regeneration may be obtained by studies of insulinoma cells. In the present study the growth and function of the rat insulinoma cell lines RINm5F and 5AH were evaluated by addition of serum, hormones, and growth factors. It was found...... of insulin mRNA content showed that the insulinoma cells only contained about 2% of that of normal rat beta-cells. These results are discussed in relation to the role of growth factors, oncogenes, and differentiation in the growth and regeneration of beta-cells....... that transferrin is the only obligatory factor whereas growth hormone, epidermal growth factor, fibroblast growth factor, and TRH had modulating effects. A heat-labile heparin binding serum factor which stimulated thymidine incorporation but not cell proliferation was demonstrated in human serum. Measurements...

SIRT6-mediated transcriptional suppression of Txnip is critical for pancreatic beta cell function and survival in mice.

Science.gov (United States)

Qin, Kunhua; Zhang, Ning; Zhang, Zhao; Nipper, Michael; Zhu, Zhenxin; Leighton, Jake; Xu, Kexin; Musi, Nicolas; Wang, Pei

2018-04-01

Better understanding of how genetic and epigenetic components control beta cell differentiation and function is key to the discovery of novel therapeutic approaches to prevent beta cell dysfunction and failure in the progression of type 2 diabetes. Our goal was to elucidate the role of histone deacetylase sirtuin 6 (SIRT6) in beta cell development and homeostasis. Sirt6 endocrine progenitor cell conditional knockout and beta cell-specific knockout mice were generated using the Cre-loxP system. Mice were assayed for islet morphology, glucose tolerance, glucose-stimulated insulin secretion and susceptibility to streptozotocin. Transcriptional regulatory functions of SIRT6 in primary islets were evaluated by RNA-Seq analysis. Reverse transcription-quantitative (RT-q)PCR and immunoblot were used to verify and investigate the gene expression changes. Chromatin occupancies of SIRT6, H3K9Ac, H3K56Ac and active RNA polymerase II were evaluated by chromatin immunoprecipitation. Deletion of Sirt6 in pancreatic endocrine progenitor cells did not affect endocrine morphology, beta cell mass or insulin production but did result in glucose intolerance and defective glucose-stimulated insulin secretion in mice. Conditional deletion of Sirt6 in adult beta cells reproduced the insulin secretion defect. Loss of Sirt6 resulted in aberrant upregulation of thioredoxin-interacting protein (TXNIP) in beta cells. SIRT6 deficiency led to increased acetylation of histone H3 lysine residue at 9 (H3K9Ac), acetylation of histone H3 lysine residue at 56 (H3K56Ac) and active RNA polymerase II at the promoter region of Txnip. SIRT6-deficient beta cells exhibited a time-dependent increase in H3K9Ac, H3K56Ac and TXNIP levels. Finally, beta cell-specific SIRT6-deficient mice showed increased sensitivity to streptozotocin. Our results reveal that SIRT6 suppresses Txnip expression in beta cells via deacetylation of histone H3 and plays a critical role in maintaining beta cell function and viability

Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with {sup 68}Ga-DOTA-octreotide: A potential PET tracer for beta cell mass measurement

Energy Technology Data Exchange (ETDEWEB)

Sako, Takeo [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Senda, Michio [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan); Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017 (Japan); Watanabe, Yasuyoshi, E-mail: yywata@riken.jp [Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047 (Japan)

2013-12-06

Highlights: •PET images showed high uptake of {sup 68}Ga-DOTA-octreotide in the normal pancreas. •{sup 68}Ga-DOTA-octreotide specifically binds to somatostatin receptors in the pancreas. •The pancreatic uptake of {sup 68}Ga-DOTA-octreotide was decreased in the diabetic rats. •{sup 68}Ga-DOTA-octreotide could be a candidate PET probe to measure the beta cell mass. -- Abstract: Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with {sup 68}Gallium ({sup 68}Ga). After intravenous injection of {sup 68}Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that {sup 68}Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of {sup 68}Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with {sup 68}Ga-DOTA-octreotide could be a potential tool for evaluating BCM.

Pancreatic beta cells express two autoantigenic forms of glutamic acid decarboxylase, a 65-kDa hydrophilic form and a 64-kDa amphiphilic form which can be both membrane-bound and soluble

DEFF Research Database (Denmark)

Christgau, S; Schierbeck, H; Aanstoot, H J

1991-01-01

The 64-kDa pancreatic beta-cell autoantigen, which is a target of autoantibodies associated with early as well as progressive stages of beta-cell destruction, resulting in insulin-dependent diabetes (IDDM) in humans, has been identified as the gamma-aminobutyric acid-synthesizing enzyme glutamic...... acid decarboxylase. We have identified two autoantigenic forms of this protein in rat pancreatic beta-cells, a Mr 65,000 (GAD65) hydrophilic and soluble form of pI 6.9-7.1 and a Mr 64,000 (GAD64) component of pI 6.7. GAD64 is more abundant than GAD65 and has three distinct forms with regard to cellular...

The putative imidazoline receptor agonist, harmane, promotes intracellular calcium mobilisation in pancreatic beta-cells.

Science.gov (United States)

Squires, Paul E; Hills, Claire E; Rogers, Gareth J; Garland, Patrick; Farley, Sophia R; Morgan, Noel G

2004-10-06

beta-Carbolines (including harmane and pinoline) stimulate insulin secretion by a mechanism that may involve interaction with imidazoline I(3)-receptors but which also appears to be mediated by actions that are additional to imidazoline receptor agonism. Using the MIN6 beta-cell line, we now show that both the imidazoline I(3)-receptor agonist, efaroxan, and the beta-carboline, harmane, directly elevate cytosolic Ca(2+) and increase insulin secretion but that these responses display different characteristics. In the case of efaroxan, the increase in cytosolic Ca(2+) was readily reversible, whereas, with harmane, the effect persisted beyond removal of the agonist and resulted in the development of a repetitive train of Ca(2+)-oscillations whose frequency, but not amplitude, was concentration-dependent. Initiation of the Ca(2+)-oscillations by harmane was independent of extracellular calcium but was sensitive to both dantrolene and high levels (20 mM) of caffeine, suggesting the involvement of ryanodine receptor-gated Ca(2+)-release. The expression of ryanodine receptor-1 and ryanodine receptor-2 mRNA in MIN6 cells was confirmed using reverse transcription-polymerase chain reaction (RT-PCR) and, since low concentrations of caffeine (1 mM) or thimerosal (10 microM) stimulated increases in [Ca(2+)](i), we conclude that ryanodine receptors are functional in these cells. Furthermore, the increase in insulin secretion induced by harmane was attenuated by dantrolene, consistent with the involvement of ryanodine receptors in mediating this response. By contrast, the smaller insulin secretory response to efaroxan was unaffected by dantrolene. Harmane-evoked changes in cytosolic Ca(2+) were maintained by nifedipine-sensitive Ca(2+)-influx, suggesting the involvement of L-type voltage-gated Ca(2+)-channels. Taken together, these data imply that harmane may interact with ryanodine receptors to generate sustained Ca(2+)-oscillations in pancreatic beta-cells and that this effect

Leucine metabolism in regulation of insulin secretion from pancreatic beta cells

OpenAIRE

Yang, Jichun; Chi, Yujing; Burkhardt, Brant R.; Guan, Youfei; Wolf, Bryan A

2010-01-01

Leucine, a the branched-chain amino acids that must be supplied in daily diet, plays an important role in controlling protein synthesis and regulating cell metabolism in various cell types. In pancreatic β cells, leucine acutely stimulates insulin secretion by serving as both metabolic fuel and allosteric activator of glutamate dehydrogenase to enhance glutaminolysis. Leucine has also been shown to regulate gene transcription and protein synthesis in pancreatic islet β cells via both mTOR-dep...

Progress in molecular nuclear medicine imaging of pancreatic beta cells

International Nuclear Information System (INIS)

Wu Haifei; Yin Hongyan; Liu Shuai; Zhang Yifan

2010-01-01

Diabetes mellitus is a common and frequently occurring disease which seriously threaten the health of human beings. Type 1 and type 2 diabetes respectively results from being destroyed and insufficient beta-cell mass. The associated symptoms appear until 50%-60% decrease of beta-cell mass. Because pancreas is deeply located in the body, with few beta-cell mass, the current methods of clinical diagnosis are invasive and late. So diagnosis of metabolism disease of beta-cell early non-invasively becomes more and more popular, imaging diagnosis of diabetes mellitus becomes the focus of researches, but how to estimate the mass of beta-cell still an important subject in imaging technology. (authors)

Pancreatitis autoinmune asociada a fibrosis retroperitoneal: evolución tras dos años de seguimiento Autoimmune pancreatitis associated with retroperitoneal fibrosis: outcome after 24 months of follow-up

Directory of Open Access Journals (Sweden)

M. Romero

2008-10-01

Full Text Available Introducción: la pancreatitis autoinmune es un tipo de pancreatitis crónica caracterizado por un infiltrado linfoplasmocitario y una elevación de IgG e IgG4, que se ha descrito asociada a diversas manifestaciones extrapancreáticas y enfermedades autoinmunes, lo cual apoya la teoría de un mecanismo autoinmune fisiopatólogico de base. Caso clínico: presentamos el caso de un varón que debutó simultáneamente con una pancreatitis autoinmune asociada a fibrosis retroperitoneal y lesión de la vía biliar extrapancreática, con respuesta total tras tratamiento con corticoides durante 4 meses y ausencia de recurrencia tras 24 meses de seguimiento. Discusión: la pancreatitis autoinmune es un tipo de pancreatitis crónica que probablemente forme parte de un proceso sistémico autoinmune, cuyas manifestaciones extrapancreáticas más frecuentes son la fibrosis retroperitoneal y las lesiones de la vía biliar extrapancreática. Su correcto diagnóstico e inicio precoz del tratamiento puede favorecer la resolución completa de las lesiones, principalmente en los casos de bajo grado de actividad, con menor probabilidad de recurrencia.Introduction: autoimmune pancreatitis is a kind of chronic pancreatitis characterized by the presence of lymphoplasmacytic infiltration and severely elevated serum IgG and IgG4, which has been associated to many extrapancreatic lesions and other autoimmune disorders, leading to the theory of an autoimmune mechanism involved in the pathogenesis of this disease. Case report: we report the case of a man who simultaneously presented with autoimmune pancreatitis associated with retroperitonal fibrosis, and a lesion of the extrapancreatic bile duct, with total response to corticosteroid treatment for 4 moths and absence of recurrence after 24 months of follow-up. Discussion: autoimmune pancreatitis is a kind of chronic pancreatitis that is probably a part of a systemic autoinmune disease, with retroperitoneal fibrosis and

Transplantation of Human Pancreatic Endoderm Cells Reverses Diabetes Post Transplantation in a Prevascularized Subcutaneous Site

Directory of Open Access Journals (Sweden)

Andrew R. Pepper

2017-06-01

Full Text Available Beta-cell replacement therapy is an effective means to restore glucose homeostasis in select humans with autoimmune diabetes. The scarcity of “healthy” human donor pancreata restricts the broader application of this effective curative therapy. “β-Like” cells derived from human embryonic stem cells (hESC, with the capacity to secrete insulin in a glucose-regulated manner, have been developed in vitro, with limitless capacity for expansion. Here we report long-term diabetes correction in mice transplanted with hESC-derived pancreatic endoderm cells (PECs in a prevascularized subcutaneous site. This advancement mitigates chronic foreign-body response, utilizes a device- and growth factor-free approach, facilitates in vivo differentiation of PECs into glucose-responsive insulin-producing cells, and reliably restores glycemic control. Basal and stimulated human C-peptide secretion was detected throughout the study, which was abolished upon graft removal. Recipient mice demonstrated physiological clearance of glucose in response to metabolic challenge and safely retrieved grafts contained viable glucose regulatory cells.

The islet beta-cell: fuel responsive and vulnerable.

Science.gov (United States)

Nolan, Christopher J; Prentki, Marc

2008-10-01

The pancreatic beta-cell senses blood nutrient levels and is modulated by neurohormonal signals so that it secretes insulin according to the need of the organism. Nutrient sensing involves marked metabolic activation, resulting in the production of coupling signals that promote insulin biosynthesis and secretion. The beta-cell's high capacity for nutrient sensing, however, necessitates reduced protection to nutrient toxicity. This potentially explains why in susceptible individuals, chronic fuel surfeit results in beta-cell failure and type 2 diabetes. Here we discuss recent insights into first, the biochemical basis of beta-cell signaling in response to glucose, amino acids and fatty acids, and second, beta-cell nutrient detoxification. We emphasize the emerging role of glycerolipid/fatty acid cycling in these processes.

Nonoverlapping roles of PD-1 and FoxP3 in maintaining immune tolerance in a novel autoimmune pancreatitis mouse model.

Science.gov (United States)

Zhang, Baihao; Chikuma, Shunsuke; Hori, Shohei; Fagarasan, Sidonia; Honjo, Tasuku

2016-07-26

PD-1 (programmed-death 1), an immune-inhibitory receptor required for immune self-tolerance whose deficiency causes autoimmunity with variable severity and tissue specificity depending on other genetic factors, is expressed on activated T cells, including the transcription factor FoxP3(+) Treg cells known to play critical roles in maintaining immune tolerance. However, whether PD-1 expression by the Treg cells is required for their immune regulatory function, especially in autoimmune settings, is still unclear. We found that mice with partial FoxP3 insufficiency developed early-onset lympho-proliferation and lethal autoimmune pancreatitis only when PD-1 is absent. The autoimmune phenotype was rescued by the transfer of FoxP3-sufficient T cells, regardless of whether they were derived from WT or PD-1-deficient mice, indicating that Treg cells dominantly protect against development of spontaneous autoimmunity without intrinsic expression of PD-1. The absence of PD-1 combined with partial FoxP3 insufficiency, however, led to generation of ex-FoxP3 T cells with proinflammatory properties and expansion of effector/memory T cells that contributed to the autoimmune destruction of target tissues. Altogether, the results suggest that PD-1 and FoxP3 work collaboratively in maintaining immune tolerance mostly through nonoverlapping pathways. Thus, PD-1 is modulating the activation threshold and maintaining the balance between regulatory and effector T cells, whereas FoxP3 is sufficient for dominant regulation through maintaining the integrity of the Treg function. We suggest that genetic or environmental factors that even moderately affect the expression of both PD-1 and FoxP3 can cause life-threatening autoimmune diseases by disrupting the T-cell homeostasis.

Fetal pancreatic beta-cell function in pregnancies complicated by maternal diabetes mellitus: relationship to fetal acidemia and macrosomia.

Science.gov (United States)

Salvesen, D R; Brudenell, J M; Proudler, A J; Crook, D; Nicolaides, K H

1993-05-01

Our purpose was to investigate the relationship between fetal pancreatic beta-cell function and fetal acidemia and macrosomia in pregnancies complicated by maternal diabetes mellitus. A cross-sectional study at the Harris Birthright Research Centre for Fetal Medicine, London, was performed. In 32 pregnancies complicated by maternal diabetes mellitus cordocentesis was performed at 36 to 39 weeks' gestation for the measurement of umbilical venous blood pH, PO2, PCO2, lactate, and glucose concentration; plasma insulin immunoreactivity; and insulin/glucose ratio. A reference range for plasma insulin and insulin/glucose ratio was constructed by studying fetal blood samples from 80 women who did not have diabetes mellitus. Mean umbilical venous blood pH was significantly lower and plasma insulin immunoreactivity and insulin/glucose ratio were significantly higher than the appropriate normal mean for gestation. There were significant associations between (1) maternal and fetal blood glucose concentrations (r = 0.95, p < 0.0001), (2) fetal blood glucose and plasma insulin immunoreactivity (r = 0.57, p < 0.01), (3) fetal plasma insulin immunoreactivity and blood pH (r = -0.39, p < 0.05), and (4) fetal insulin/glucose ratio and degree of macrosomia (r = 0.76, p < 0.0001). Fetal pancreatic beta-cell hyperplasia is implicated in the pathogenesis of both fetal acidemia and macrosomia.

Positron emission tomography study on pancreatic somatostatin receptors in normal and diabetic rats with 68Ga-DOTA-octreotide: a potential PET tracer for beta cell mass measurement.

Science.gov (United States)

Sako, Takeo; Hasegawa, Koki; Nishimura, Mie; Kanayama, Yousuke; Wada, Yasuhiro; Hayashinaka, Emi; Cui, Yilong; Kataoka, Yosky; Senda, Michio; Watanabe, Yasuyoshi

2013-12-06

Diabetes mellitus (DM) is a metabolic disorder characterized by hyperglycemia, and the loss or dysfunction of pancreatic beta cells has been reported before the appearance of clinical symptoms and hyperglycemia. To evaluate beta cell mass (BCM) for improving the detection and treatment of DM at earlier stages, we focused on somatostatin receptors that are highly expressed in the pancreatic beta cells, and developed a positron emission tomography (PET) probe derived from octreotide, a metabolically stable somatostatin analog. Octreotide was conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), a chelating agent, and labeled with (68)Gallium ((68)Ga). After intravenous injection of (68)Ga-DOTA-octreotide, a 90-min emission scan of the abdomen was performed in normal and DM model rats. The PET studies showed that (68)Ga-DOTA-octreotide radioactivity was highly accumulated in the pancreas of normal rats and that the pancreatic accumulation was significantly reduced in the rats administered with an excess amount of unlabeled octreotide or after treatment with streptozotocin, which was used for the chemical induction of DM in rats. These results were in good agreement with the ex vivo biodistribution data. These results indicated that the pancreatic accumulation of (68)Ga-DOTA-octreotide represented specific binding to the somatostatin receptors and reflected BCM. Therefore, PET imaging with (68)Ga-DOTA-octreotide could be a potential tool for evaluating BCM. Copyright © 2013 Elsevier Inc. All rights reserved.

Role of transcription factor KLF11 and its diabetes-associated gene variants in pancreatic beta cell function

DEFF Research Database (Denmark)

Neve, Bernadette; Fernandez-Zapico, Martin E; Ashkenazi-Katalan, Vered

2005-01-01

in beta cells. Genetic analysis of the KLF11 gene revealed two rare variants (Ala347Ser and Thr220Met) that segregate with diabetes in families with early-onset type 2 diabetes, and significantly impair its transcriptional activity. In addition, analysis of 1,696 type 2 diabetes mellitus and 1......,776 normoglycemic subjects show a frequent polymorphic Gln62Arg variant that significantly associates with type 2 diabetes mellitus in North European populations (OR = 1.29, P = 0.00033). Moreover, this variant alters the corepressor mSin3A-binding activity of KLF11, impairs the activation of the insulin promoter...... and shows lower levels of insulin expression in pancreatic beta cells. In addition, subjects carrying the Gln62Arg allele show decreased plasma insulin after an oral glucose challenge. Interestingly, all three nonsynonymous KLF11 variants show increased repression of the catalase 1 promoter, suggesting...

Pancreatic differentiation of Pdx1-GFP reporter mouse induced pluripotent stem cells.

Science.gov (United States)

Porciuncula, Angelo; Kumar, Anujith; Rodriguez, Saray; Atari, Maher; Araña, Miriam; Martin, Franz; Soria, Bernat; Prosper, Felipe; Verfaillie, Catherine; Barajas, Miguel

2016-12-01

Efficient induction of defined lineages in pluripotent stem cells constitutes the determinant step for the generation of therapeutically relevant replacement cells to potentially treat a wide range of diseases, including diabetes. Pancreatic differentiation has remained an important challenge in large part because of the need to differentiate uncommitted pluripotent stem cells into highly specialized hormone-secreting cells, which has been shown to require a developmentally informed step-by-step induction procedure. Here, in the framework of using induced pluripotent stem cells (iPSCs) to generate pancreatic cells for pancreatic diseases, we have generated and characterized iPSCs from Pdx1-GFP transgenic mice. The use of a GFP reporter knocked into the endogenous Pdx1 promoter allowed us to monitor pancreatic induction based on the expression of Pdx1, a pancreatic master transcription factor, and to isolate a pure Pdx1-GFP + population for downstream applications. Differentiated cultures timely expressed markers specific to each stage and end-stage progenies acquired a rather immature beta-cell phenotype, characterized by polyhormonal expression even among cells highly expressing the Pdx1-GFP reporter. Our findings highlight the utility of employing a fluorescent protein reporter under the control of a master developmental gene in order to devise novel differentiation protocols for relevant cell types for degenerative diseases such as pancreatic beta cells for diabetes. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

On the coherent behavior of pancreatic beta cell clusters

Energy Technology Data Exchange (ETDEWEB)

Loppini, Alessandro, E-mail: a.loppini@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Capolupo, Antonio, E-mail: capolupo@sa.infn.it [Physics Department, University of Salerno, Fisciano, 84084 (Italy); Cherubini, Christian, E-mail: c.cherubini@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); International Center for Relativistic Astrophysics, University Campus Bio-Medico, Via A. del Portillo 21, I-00128, Rome (Italy); Gizzi, Alessio, E-mail: a.gizzi@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Bertolaso, Marta, E-mail: m.bertolaso@unicampus.it [Faculty of Engineering and Institute of Philosophy of Scientific and Technological Practice, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); Filippi, Simonetta, E-mail: s.filippi@unicampus.it [Nonlinear Physics and Mathematical Modeling Lab, University Campus Bio-Medico, Via A. del Portillo 21, I-00128 Rome (Italy); International Center for Relativistic Astrophysics, University Campus Bio-Medico, Via A. del Portillo 21, I-00128, Rome (Italy); Vitiello, Giuseppe, E-mail: vitiello@sa.infn.it [Physics Department, University of Salerno, Fisciano, 84084 (Italy)

2014-09-12

Beta cells in pancreas represent an example of coupled biological oscillators which via communication pathways, are able to synchronize their electrical activity, giving rise to pulsatile insulin release. In this work we numerically analyze scale free self-similarity features of membrane voltage signal power density spectrum, through a stochastic dynamical model for beta cells in the islets of Langerhans fine tuned on mouse experimental data. Adopting the algebraic approach of coherent state formalism, we show how coherent molecular domains can arise from proper functional conditions leading to a parallelism with “phase transition” phenomena of field theory. - Highlights: • Beta cells in pancreas are coupled oscillators able to synchronize their activity. • We analyze scale free self-similarity features for beta cells. • We adopt the algebraic approach of coherent state formalism. • We show that coherent molecular domains arise from functional conditions.

The Importance of REST for Development and Function of Beta Cells

DEFF Research Database (Denmark)

Martin, David; Grapin-Botton, Anne

2017-01-01

that are crucial for both neuronal and pancreatic endocrine function, through the recruitment of multiple transcriptional and epigenetic co-regulators. REST targets include genes encoding transcription factors, proteins involved in exocytosis, synaptic transmission or ion channeling, and non-coding RNAs. REST......Beta cells are defined by the genes they express, many of which are specific to this cell type, and ensure a specific set of functions. Beta cells are also defined by a set of genes they should not express (in order to function properly), and these genes have been called forbidden genes. Among...... these, the transcriptional repressor RE-1 Silencing Transcription factor (REST) is expressed in most cells of the body, excluding most populations of neurons, as well as pancreatic beta and alpha cells. In the cell types where it is expressed, REST represses the expression of hundreds of genes...

Retroperitoneal disorders associated with IgG4-related autoimmune pancreatitis

OpenAIRE

Hara, Noboru; Kawaguchi, Makoto; Takeda, Keisuke; Zen, Yoh

2014-01-01

IgG4-related autoimmune pancreatitis is frequently accompanied by relevant lesions in the genitourinary tract and retroperitoneal organs, which cause various clinical problems, ranging from non-specific back pain or bladder outlet obstruction to renal failure. The diagnosis of IgG4-related retroperitoneal fibrosis requires a multidisciplinary approach, including serological tests, histological examination, imaging analysis, and susceptibility to steroid therapy. Radiological examinations are ...

Role of bone marrow cells in the development of pancreatic fibrosis in a rat model of pancreatitis induced by a choline-deficient/ethionine-supplemented diet

Energy Technology Data Exchange (ETDEWEB)

Akita, Shingo; Kubota, Koji [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Kobayashi, Akira, E-mail: kbys@shinshu-u.ac.jp [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Misawa, Ryosuke; Shimizu, Akira; Nakata, Takenari; Yokoyama, Takahide [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Takahashi, Masafumi [Center for Molecular Medicine Division of Bioimaging Sciences, Jichi Medical University, 3311-1 Yakushiji, Shimono, Tochigi 329-0498 (Japan); Miyagawa, Shinichi [Department of Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan)

2012-04-20

Highlights: Black-Right-Pointing-Pointer BMC-derived PSCs play a role in a rat CDE diet-induced pancreatitis model. Black-Right-Pointing-Pointer BMC-derived PSCs contribute mainly to the early stage of pancreatic fibrosis. Black-Right-Pointing-Pointer BMC-derived activated PSCs can produce PDGF and TGF {beta}1. -- Abstract: Bone marrow cell (BMC)-derived myofibroblast-like cells have been reported in various organs, including the pancreas. However, the contribution of these cells to pancreatic fibrosis has not been fully discussed. The present study examined the possible involvement of pancreatic stellate cells (PSCs) originating from BMCs in the development of pancreatic fibrosis in a clinically relevant rat model of acute pancreatitis induced by a choline-deficient/ethionine-supplemented (CDE) diet. BMCs from female transgenic mice ubiquitously expressing green fluorescent protein (GFP) were transplanted into lethally irradiated male rats. Once chimerism was established, acute pancreatitis was induced by a CDE diet. Chronological changes in the number of PSCs originating from the donor BMCs were examined using double immunofluorescence for GFP and markers for PSCs, such as desmin and alpha smooth muscle actin ({alpha}SMA), 1, 3 and 8 weeks after the initiation of CDE feeding. We also used immunohistochemical staining to evaluate whether the PSCs from the BMCs produce growth factors, such as platelet-derived growth factor (PDGF) and transforming growth factor (TGF) {beta}1. The percentage of BMC-derived activated PSCs increased significantly, peaking after 1 week of CDE treatment (accounting for 23.3 {+-} 0.9% of the total population of activated PSCs) and then decreasing. These cells produced both PDGF and TGF{beta}1 during the early stage of pancreatic fibrosis. Our results suggest that PSCs originating from BMCs contribute mainly to the early stage of pancreatic injury, at least in part, by producing growth factors in a rat CDE diet-induced pancreatitis model.

Basophils activated via TLR signaling may contribute to pathophysiology of type 1 autoimmune pancreatitis.

Science.gov (United States)

Yanagawa, Masato; Uchida, Kazushige; Ando, Yugo; Tomiyama, Takashi; Yamaguchi, Takashi; Ikeura, Tsukasa; Fukui, Toshiro; Nishio, Akiyoshi; Uemura, Yoshiko; Miyara, Takayuki; Okamoto, Hiroyuki; Satoi, Souhei; Okazaki, Kazuichi

2018-03-01

Pathophysiology of type 1 autoimmune pancreatitis (AIP) is still unclear. We previously reported that M2 macrophages might play an important role in type 1 AIP. Recently, it has been reported that basophils regulate differentiation to M2 macrophages. In this study, we investigated basophils from the pancreatic tissue and peripheral blood of individuals with type 1 AIP. By using immunohistochemistry, we investigated basophils in pancreatic tissue from 13 patients with type 1 AIP and examined expression of toll-like receptors (TLRs) by these cells. Additionally, we obtained peripheral blood samples from 27 healthy subjects, 40 patients with type 1 AIP, 8 patients with alcoholic chronic pancreatitis, 10 patients with bronchial asthma, and 10 patients with atopic dermatitis, and analyzed activation of basophils by stimulating them with ligands of TLR1-9. We also compared TLR expression in basophils from the tissue and blood samples. Basophils were detected in pancreatic tissues from 10 of 13 patients with type 1 AIP. Flow cytometric analysis revealed that the ratios of basophils activated by TLR4 stimulation in type 1 AIP (9.875 ± 1.148%) and atopic dermatitis (11.768 ± 1.899%) were significantly higher than those in healthy subjects (5.051 ± 0.730%; P pathophysiology of type 1 AIP.

Beta-cell lines derived from transgenic mice expressing a hybrid insulin gene-oncogene

DEFF Research Database (Denmark)

Efrat, S; Linde, S; Kofod, Hans

1988-01-01

Three pancreatic beta-cell lines have been established from insulinomas derived from transgenic mice carrying a hybrid insulin-promoted simian virus 40 tumor antigen gene. The beta tumor cell (beta TC) lines maintain the features of differentiated beta cells for about 50 passages in culture. The ...... both to immortalize a rare cell type and to provide a selection for the maintenance of its differentiated phenotype....

Distinct pathophysiological cytokine profiles for discrimination between autoimmune pancreatitis, chronic pancreatitis, and pancreatic ductal adenocarcinoma.

Science.gov (United States)

Ghassem-Zadeh, Sahar; Gaida, Matthias M; Szanyi, Szilard; Acha-Orbea, Hans; Frossard, Jean-Louis; Hinz, Ulf; Hackert, Thilo; Strobel, Oliver; Felix, Klaus

2017-06-02

Discriminating between autoimmune pancreatitis (AIP), chronic pancreatitis (CP), and pancreatic ductal adenocarcinoma (PDAC) can be challenging. In this retrospective study, levels of serum and tissue cytokines were analyzed as part of the clinical strategy for the preoperative differentiation between AIP and PDAC. The identification of differential cytokine profiles may help to prevent unnecessary surgical resection and allow optimal treatment of these pathologies. To compare the cytokine profiles of AIP, CP, and PDAC patients, serum and pancreatic tissue homogenates were subjected to multiplex analysis of 17 inflammatory mediators. In total, serum from 73 patients, composed of 29 AIP (14 AIP-1 and 15 AIP-2), 17 CP, and 27 PDAC, and pancreatic tissue from 36 patients, including 12 AIP (six AIP-1 and six AIP-2), 12 CP, and 12 PDAC, were analyzed. Comparing AIP and PDAC patients' serum, significantly higher concentrations were found in AIP for interleukins IL-1β, IL-7, IL-13, and granulocyte colony-stimulating factor (G-CSF). G-CSF also allowed discrimination of AIP from CP. Furthermore, once AIP was divided into subtypes, significantly higher serum levels for IL-7 and G-CSF were measured in both subtypes of AIP and in AIP-2 for IL-1β when compared to PDAC. G-CSF and TNF-α were also significantly differentially expressed in tissue homogenates between AIP-2 and PDAC. The cytokines IL-1β, IL-7, and G-CSF can be routinely measured in patients' serum, providing an elegant and non-invasive approach for differential diagnosis. G-CSF is a good candidate to supplement the currently known serum markers in predictive tests for AIP and represents a basis for a combined blood test to differentiate AIP and particularly AIP-2 from PDAC, enhancing the possibility of appropriate treatment.

Chronology of endocrine differentiation and beta-cell neogenesis.

Science.gov (United States)

Miyatsuka, Takeshi

2016-01-01

Diabetes is a chronic and incurable disease, which results from absolute or relative insulin insufficiency. Therefore, pancreatic beta cells, which are the only type of cell that expresses insulin, is considered to be a potential target for the cure of diabetes. Although the findings regarding beta-cell neogenesis during pancreas development have been exploited to induce insulin-producing cells from non-beta cells, there are still many hurdles towards generating fully functional beta cells that can produce high levels of insulin and respond to physiological signals. To overcome these problems, a solid understanding of pancreas development and beta-cell formation is required, and several mouse models have been developed to reveal the unique features of each endocrine cell type at distinct developmental time points. Here I review our understanding of pancreas development and endocrine differentiation focusing on recent progresses in improving temporal cell labeling in vivo.

Histological evaluation of obliterative phlebitis for the diagnosis of autoimmune pancreatitis.

Science.gov (United States)

Miyabe, Katsuyuki; Notohara, Kenji; Nakazawa, Takahiro; Hayashi, Kazuki; Naitoh, Itaru; Okumura, Fumihiro; Shimizu, Shuya; Yoshida, Michihiro; Yamashita, Hiroaki; Takahashi, Satoru; Ohara, Hirotaka; Joh, Takashi

2014-04-01

Obliterative phlebitis is a useful pathological finding for the diagnosis of lymphoplasmacytic sclerosing pancreatitis (LPSP), or type 1 autoimmune pancreatitis. The present study evaluated histological findings of obliterative phlebitis, including the significance of adding Elastica van Gieson stain (EVG) in comparison with other pancreatic conditions. Specimens of LPSP (n = 18), chronic pancreatitis (CP; n = 24), and pancreatic ductal adenocarcinoma (PDA; n = 45) were enrolled. Obliterative venous lesions (OVLs), defined as the presence of inflammatory cells and/or fibrosis inside the tunica adventitia, were counted and compared between hematoxylin and eosin stain (H&E) and EVG. OVLs were classified into three types: OVL-1, lymphoplasmacytic infiltration and fibrosis against a loose textured background; OVL-2, dense fibrosis with minimal or no lymphoplasmacytic infiltration; and OVL-3, densely packed lymphoplasmacytic infiltration without fibrosis. OVL type and OVL size were compared between disease groups. OVL counts in LPSP, CP, and PDA were significantly higher with EVG than with H&E (p < 0.001). OVL-1 was most common in LPSP (H&E 92.4 %, EVG 79.8 %), and was identified in almost all cases of LPSP, but was less common in CP and PDA. Maximum diameter and OVL count in 1 cm(2) of OVL-1 were high for LPSP. Maximum diameter of OVL-1 ≥150 μm was observed in 17 LPSP, 0 CP, and 1 PDA cases (sensitivity 94.4 %, specificity 98.6 %). Additional EVG is useful for excluding conditions mimicking OVL-1 or detecting OVL in small specimens. The presence of OVL-1 with diameter ≥150 μm is highly diagnostic for LPSP.

Pancreatic β-cells activate a JunB/ATF3-dependent survival pathway during inflammation

DEFF Research Database (Denmark)

Gurzov, E N; Barthson, J; Marhfour, I

2012-01-01

Destruction of insulin-producing pancreatic β-cells by local autoimmune inflammation is a hallmark of type 1 diabetes. Histochemical analysis of pancreases from non-obese diabetic mice indicated activation of the transcription factor JunB/AP-1 (activator protein-1) after autoimmune infiltration......-cells and human islet cells against pro-inflammatory mediators. These results were confirmed in genetically modified islets derived from Ubi-JunB transgenic mice. Our findings identify ATF3 as a novel downstream target of JunB in the survival mechanism of β-cells under inflammatory stress....

Effect of atorvastatin on pancreatic Beta-cell function and insulin resistance in type 2 diabetes mellitus patients: a randomized pilot study.

Science.gov (United States)

Goyal, Aman; Singh, Surender; Tandon, Nikhil; Gupta, Nandita; Gupta, Yogendra Kumar

2014-12-01

Statins are commonly used for the management of dyslipidemia in type 2 diabetes mellitus patients. We hypothesized that atorvastatin could modulate the beta-cell function by altering the levels of proapoptotic and antiapoptotic lipoproteins and could also have an effect on insulin resistance. The aim of the present pilot study was to assess the effect of atorvastatin 10 mg on pancreatic beta-cell function and insulin resistance in patients with hyperlipidemia and type 2 diabetes by using the homeostasis model assessment-2 (HOMA2) index. Fifty-one type 2 diabetes patients receiving oral antidiabetes drugs, not taking statins, with baseline low-density lipoprotein cholesterol between 2.6 mmol/L and 4.1 mmol/L were included. Forty-three patients (21 in placebo group and 22 in atorvastatin group) completed the study and were taken up for final analysis. Fasting blood samples were obtained at baseline and at 12 weeks to determine levels of blood glucose, lipid profile, insulin, C-peptide and glycosylated hemoglobin (A1C). Atorvastatin nonsignificantly increased fasting serum insulin (+14.29%, p=0.18), accompanied by marginal nonsignificant increases in fasting plasma glucose and A1C. There was a decrease in HOMA2 percent beta-cell function (-2.9%, p=0.72) and increase in HOMA2 insulin resistance (+14%, p=0.16) in the atorvastatin group as compared with baseline, but the difference was not statistically significant. Atorvastatin in the dose used failed to produce significant change in pancreatic beta-cell function and insulin resistance in type 2 diabetes patients as assessed by the HOMA2 index. The possible explanations include absence of lipotoxicity at prevailing levels of dyslipidemia at baseline or inadequacy of statin dose used in the study. (Clinical Trials Registry-India: CTRI/2008/091/000099). Copyright © 2014 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Autoimmune pancreatitis. An update

International Nuclear Information System (INIS)

Helmberger, T.

2016-01-01

Autoimmune pancreatitis (AIP) is a rare disease, the pathophysiological understanding of which has been greatly improved over the last years. The most common form, type 1 AIP belongs to the IgG4-related diseases and must be distinguished from type 2 AIP, which is a much rarer entity associated with chronic inflammatory bowel disease. Clinically, there is an overlap with pancreatic cancer. Imaging and further criteria, such as serological and histological parameters are utilized for a differentiation between both entities in order to select the appropriate therapy and to avoid the small but ultimately unnecessary number of pancreatectomies. The diagnostics of AIP are complex, whereby the consensus criteria of the International Association of Pancreatology have become accepted as the parameters for discrimination. These encompass five cardinal criteria and one therapeutic criterion. By applying these criteria AIP can be diagnosed with a sensitivity of 84.9 %, a specificity of 100 % and an accuracy of 93.8 %. The diagnosis of AIP is accomplished by applying several parameters of which two relate to imaging. As for the routine diagnostics of the pancreas these are ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). Important for the differential diagnosis is the exclusion of signs of local and remote tumor spread for which CT and MRI are established. The essential diagnostic parameter of histology necessitates sufficient sample material, which cannot usually be acquired by a fine needle biopsy. CT or MRI are the reference standard methods for identification of the optimal puncture site and imaging-assisted (TruCut) biopsy. In patients presenting with unspecific upper abdominal pain, painless jaundice combined with the suspicion of a pancreatic malignancy in imaging but a mismatch of secondary signs of malignancy, AIP should also be considered as a differential diagnosis. As the diagnosis of AIP only partially relies on imaging radiologists also

Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.

Directory of Open Access Journals (Sweden)

Holger A Russ

Full Text Available Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, attempts at expanding human islet cells in tissue culture result in loss of beta-cell phenotype. Using a lineage-tracing approach we provided evidence for massive proliferation of beta-cell-derived (BCD cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT. Epigenetic analyses indicate that key beta-cell genes maintain open chromatin structure in expanded BCD cells, although they are not transcribed. Here we investigated whether BCD cells can be redifferentiated into beta-like cells.Redifferentiation conditions were screened by following activation of an insulin-DsRed2 reporter gene. Redifferentiated cells were characterized for gene expression, insulin content and secretion assays, and presence of secretory vesicles by electron microscopy. BCD cells were induced to redifferentiate by a combination of soluble factors. The redifferentiated cells expressed beta-cell genes, stored insulin in typical secretory vesicles, and released it in response to glucose. The redifferentiation process involved mesenchymal-epithelial transition, as judged by changes in gene expression. Moreover, inhibition of the EMT effector SLUG (SNAI2 using shRNA resulted in stimulation of redifferentiation. Lineage-traced cells also gave rise at a low rate to cells expressing other islet hormones, suggesting transition of BCD cells through an islet progenitor-like stage during redifferentiation.These findings demonstrate for the first time that expanded dedifferentiated beta cells can be induced to redifferentiate in culture. The findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug

Fetal and neonatal nicotine exposure in Wistar rats causes progressive pancreatic mitochondrial damage and beta cell dysfunction.

Directory of Open Access Journals (Sweden)

Jennifer E Bruin

Full Text Available Nicotine replacement therapy (NRT is currently recommended as a safe smoking cessation aid for pregnant women. However, fetal and neonatal nicotine exposure in rats causes mitochondrial-mediated beta cell apoptosis at weaning, and adult-onset dysglycemia, which we hypothesize is related to progressive mitochondrial dysfunction in the pancreas. Therefore in this study we examined the effect of fetal and neonatal exposure to nicotine on pancreatic mitochondrial structure and function during postnatal development. Female Wistar rats were given saline (vehicle control or nicotine bitartrate (1 mg/kg/d via subcutaneous injection for 2 weeks prior to mating until weaning. At 3-4, 15 and 26 weeks of age, oral glucose tolerance tests were performed, and pancreas tissue was collected for electron microscopy, enzyme activity assays and islet isolation. Following nicotine exposure mitochondrial structural abnormalities were observed beginning at 3 weeks and worsened with advancing age. Importantly the appearance of these structural defects in nicotine-exposed animals preceded the onset of glucose intolerance. Nicotine exposure also resulted in significantly reduced pancreatic respiratory chain enzyme activity, degranulation of beta cells, elevated islet oxidative stress and impaired glucose-stimulated insulin secretion compared to saline controls at 26 weeks of age. Taken together, these data suggest that maternal nicotine use during pregnancy results in postnatal mitochondrial dysfunction that may explain, in part, the dysglycemia observed in the offspring from this animal model. These results clearly indicate that further investigation into the safety of NRT use during pregnancy is warranted.

Regulation of Pancreatic β Cell Mass by Cross-Interaction between CCAAT Enhancer Binding Protein β Induced by Endoplasmic Reticulum Stress and AMP-Activated Protein Kinase Activity.

Directory of Open Access Journals (Sweden)

Tomokazu Matsuda

Full Text Available During the development of type 2 diabetes, endoplasmic reticulum (ER stress leads to not only insulin resistance but also to pancreatic beta cell failure. Conversely, cell function under various stressed conditions can be restored by reducing ER stress by activating AMP-activated protein kinase (AMPK. However, the details of this mechanism are still obscure. Therefore, the current study aims to elucidate the role of AMPK activity during ER stress-associated pancreatic beta cell failure. MIN6 cells were loaded with 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide (AICAR and metformin to assess the relationship between AMPK activity and CCAAT enhancer binding protein β (C/EBPβ expression levels. The effect of C/EBPβ phosphorylation on expression levels was also investigated. Vildagliptin and metformin were administered to pancreatic beta cell-specific C/EBPβ transgenic mice to investigate the relationship between C/EBPβ expression levels and AMPK activity in the pancreatic islets. When pancreatic beta cells are exposed to ER stress, the accumulation of the transcription factor C/EBPβ lowers the AMP/ATP ratio, thereby decreasing AMPK activity. In an opposite manner, incubation of MIN6 cells with AICAR or metformin activated AMPK, which suppressed C/EBPβ expression. In addition, administration of the dipeptidyl peptidase-4 inhibitor vildagliptin and metformin to pancreatic beta cell-specific C/EBPβ transgenic mice decreased C/EBPβ expression levels and enhanced pancreatic beta cell mass in proportion to the recovery of AMPK activity. Enhanced C/EBPβ expression and decreased AMPK activity act synergistically to induce ER stress-associated pancreatic beta cell failure.

[Relationship between the expression of beta-cat, cyclin D1 and c-myc and the occurance and biological behavior of pancreatic cancer].

Science.gov (United States)

Li, Yu-jun; Ji, Xiang-rui

2003-06-01

To study the relationship between the abnormal expression of beta-catenin (beta-cat) and the high expressions of cyclin D1 and c-myc and the occurance, proliferation, infiltration, metastasis and prognosis of pancreatic cancer, and to provide rational basis for the clinical diagnosis and treatment. Immunohistochemical PicTure trade mark was used to examine the expressions of beta-cat, cyclin D1 and c-myc in 47 cases of the cancerous tissue of pancreas, 12 cases of the pancreatic intraepithelial neoplasia and 10 cases of normal tissue of pancreas, respectively. Pancreatic cancer proliferation cell nuclear antigen (PCNA) was also tested as the index of the extent of proliferation of the pancreatic cancer. beta-cat was expressed normally in the 10 cases of the normal pancreatic tissue, while cyclin D1 and c-myc were negative. The expression rates of beta-cat, cyclin D1 and c-myc in the tissues of the pancreatic intraepithelial neoplasia and the pancreatic cancer had no significant difference [6/12 and 68.1% (32/47), 6/12 and 74.5% (35/47), 5/12 and 70.2% (33/47) respectively;P values were all more than 0.05]. The abnormal expression rate of beta-cat was significantly correlated to the metastasis of the pancreatic cancer and the one-year survival rate (both P 0.05). The expression rate of cyclin D1 was correlated with the proliferation of the pancreatic cancer and the extent of differentiation (both P 0.05). The expression rate of c-myc was not correlated with the size, the extent of proliferation, infiltration, metastasis, or one-year survival rate (both P > 0.05), but closely with the proliferation activity of the cancerous tissue of pancreas (P < 0.05). The abnormal expression of beta-cat and the high expressions of cyclin D1 and c-myc had a parallel relationship with the pancreatic intraepithelial neoplasia and pancreatic cancer (both P < 0.05, gamma = 1.000, 0.845, 0.437, 0.452). The abnormal expression of beta-cat activates cyclin D1 and c-myc, and results in the

Role of the mitochondria in immune-mediated apoptotic death of the human pancreatic β cell line βLox5.

Directory of Open Access Journals (Sweden)

Yaíma L Lightfoot

Full Text Available Mitochondria are indispensable in the life and death of many types of eukaryotic cells. In pancreatic beta cells, mitochondria play an essential role in the secretion of insulin, a hormone that regulates blood glucose levels. Unregulated blood glucose is a hallmark symptom of diabetes. The onset of Type 1 diabetes is preceded by autoimmune-mediated destruction of beta cells. However, the exact role of mitochondria has not been assessed in beta cell death. In this study, we examine the role of mitochondria in both Fas- and proinflammatory cytokine-mediated destruction of the human beta cell line, βLox5. IFNγ primed βLox5 cells for apoptosis by elevating cell surface Fas. Consequently, βLox5 cells were killed by caspase-dependent apoptosis by agonistic activation of Fas, but only after priming with IFNγ. This beta cell line undergoes both apoptotic and necrotic cell death after incubation with the combination of the proinflammatory cytokines IFNγ and TNFα. Additionally, both caspase-dependent and -independent mechanisms that require proper mitochondrial function are involved. Mitochondrial contributions to βLox5 cell death were analyzed using mitochondrial DNA (mtDNA depleted βLox5 cells, or βLox5 ρ(0 cells. βLox5 ρ(0 cells are not sensitive to IFNγ and TNFα killing, indicating a direct role for the mitochondria in cytokine-induced cell death of the parental cell line. However, βLox5 ρ(0 cells are susceptible to Fas killing, implicating caspase-dependent extrinsic apoptotic death is the mechanism by which these human beta cells die after Fas ligation. These data support the hypothesis that immune mediators kill βLox5 cells by both mitochondrial-dependent intrinsic and caspase-dependent extrinsic pathways.

Transgenic overexpression of active calcineurin in beta-cells results in decreased beta-cell mass and hyperglycemia.

Directory of Open Access Journals (Sweden)

Ernesto Bernal-Mizrachi

2010-08-01

Full Text Available Glucose modulates beta-cell mass and function through an initial depolarization and Ca(2+ influx, which then triggers a number of growth regulating signaling pathways. One of the most important downstream effectors in Ca(2+ signaling is the calcium/Calmodulin activated serine threonine phosphatase, calcineurin. Recent evidence suggests that calcineurin/NFAT is essential for beta-cell proliferation, and that in its absence loss of beta-cells results in diabetes. We hypothesized that in contrast, activation of calcineurin might result in expansion of beta-cell mass and resistance to diabetes.To determine the role of activation of calcineurin signaling in the regulation of pancreatic beta-cell mass and proliferation, we created mice that expressed a constitutively active form of calcineurin under the insulin gene promoter (caCn(RIP. To our surprise, these mice exhibited glucose intolerance. In vitro studies demonstrated that while the second phase of Insulin secretion is enhanced, the overall insulin secretory response was conserved. Islet morphometric studies demonstrated decreased beta-cell mass suggesting that this was a major component responsible for altered Insulin secretion and glucose intolerance in caCn(RIP mice. The reduced beta-cell mass was accompanied by decreased proliferation and enhanced apoptosis.Our studies identify calcineurin as an important factor in controlling glucose homeostasis and indicate that chronic depolarization leading to increased calcineurin activity may contribute, along with other genetic and environmental factors, to beta-cell dysfunction and diabetes.

Planar Cell Polarity Controls Pancreatic Beta Cell Differentiation and Glucose Homeostasis

DEFF Research Database (Denmark)

Cortijo, Cedric; Gouzi, Mathieu; Tissir, Fadel

2012-01-01

glucose clearance. Loss of Celsr2 and 3 leads to a reduction of Jun phosphorylation in progenitors, which, in turn, reduces beta cell differentiation from endocrine progenitors. These results highlight the importance of the PCP pathway in cell differentiation in vertebrates. In addition, they reveal.......5 synchronously to apicobasal polarization of pancreas progenitors. Loss of function of the two PCP core components Celsr2 and Celsr3 shows that they control the differentiation of endocrine cells from polarized progenitors, with a prevalent effect on insulin-producing beta cells. This results in a decreased...

Pancreatic stellate cells enhance stem cell-like phenotypes in pancreatic cancer cells

International Nuclear Information System (INIS)

Hamada, Shin; Masamune, Atsushi; Takikawa, Tetsuya; Suzuki, Noriaki; Kikuta, Kazuhiro; Hirota, Morihisa; Hamada, Hirofumi; Kobune, Masayoshi; Satoh, Kennichi; Shimosegawa, Tooru

2012-01-01

Highlights: ► Pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. ► Pancreatic cancer cells co-cultured with PSCs showed enhanced spheroid formation. ► Expression of stem cell-related genes ABCG2, Nestin and LIN28 was increased. ► Co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. ► This study suggested a novel role of PSCs as a part of the cancer stem cell niche. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Recent studies have identified that a portion of cancer cells, called “cancer stem cells”, within the entire cancer tissue harbor highly tumorigenic and chemo-resistant phenotypes, which lead to the recurrence after surgery or re-growth of the tumor. The mechanisms that maintain the “stemness” of these cells remain largely unknown. We hypothesized that PSCs might enhance the cancer stem cell-like phenotypes in pancreatic cancer cells. Indirect co-culture of pancreatic cancer cells with PSCs enhanced the spheroid-forming ability of cancer cells and induced the expression of cancer stem cell-related genes ABCG2, Nestin and LIN28. In addition, co-injection of PSCs enhanced tumorigenicity of pancreatic cancer cells in vivo. These results suggested a novel role of PSCs as a part of the cancer stem cell niche.

Lysine deacetylase inhibition prevents diabetes by chromatin-independent immunoregulation and beta-cell protection

NARCIS (Netherlands)

Christensen, D.P.; Gysemans, C.; Lundh, M.; Dahllof, M.S.; Noesgaard, D.; Schmidt, S.F.; Mandrup, S; Birkbak, N.; Workman, C.T.; Piemonti, L.; Blaabjerg, L.; Monzani, V.; Fossati, G.; Mascagni, P.; Paraskevas, S.; Aikin, R.A.; Billestrup, N.; Grunnet, L.G.; Dinarello, C.A.; Mathieu, C.; Mandrup-Poulsen, T.

2014-01-01

Type 1 diabetes is due to destruction of pancreatic beta-cells. Lysine deacetylase inhibitors (KDACi) protect beta-cells from inflammatory destruction in vitro and are promising immunomodulators. Here we demonstrate that the clinically well-tolerated KDACi vorinostat and givinostat revert diabetes

Development of biomarker specific of pancreatic beta cells (incretin radiolabelled) for image of beta functional mass in diabetic and obese: study in animal model; Desenvolvimento de biomarcador específico de células beta pancreáticas (incretina radiomarcada) para imagem da massa beta funcional em diabéticos e obesos: estudo em modelo animal

Energy Technology Data Exchange (ETDEWEB)

Seo, Daniele

2017-07-01

Increased prevalence of obesity worldwide, has become a vast concern, stimulating investigations focusing prevention and therapy of this condition. The association of type 2 diabetes or insulin resistance aggravates the prognosis of obesity. Even patients successfully submitted to bariatric or metabolic surgery, may not be cured of diabetes, as improvement of circulating values of glucose and insulin not necessarily reflects recovery of pancreatic beta cell mass. There is no consensus about how to estimate beta cell mass in vivo. Available tools suffer from low sensitivity and specificity, often being as well cumbersome and expensive. Radiolabeled incretins, such as glucagon-like-peptide 1 (GLP-1) analogs, seem to be promising options for the measurement of beta cell mass in diabetes and insulinoma. The objective of this study was the development of two conjugates of GLP-1 analog, radiolabeled with {sup 99m} Technetium, as a noninvasive imaging method for the estimation of pancreatic beta cell mass, in the presence of obesity. Animal models were selected, including hyperlipidic diet-induced obesity, diet restricted obesity, and as controls, alloxan diabetes. Results indicated that both radiotracers achieved over 97% radiochemical yield. The most successful product was {sup 99m}Tc-HYNIC-βAla-Exendin-4. Low beta cell mass uptake occurred in diet-induced obesity. Diet-restricted obesity, with substantial shedding of excess body weight, was followed by remarkable decrease of fasting blood glucose, however beta cell mass uptake was only mildly improved. Future studies are recommended in obesity, type 2 diabetes, and dieting, including bariatric and metabolic operations. (author)

Redox Homeostasis in Pancreatic beta Cells

Czech Academy of Sciences Publication Activity Database

Ježek, Petr; Dlasková, Andrea; Plecitá-Hlavatá, Lydie

2012-01-01

Roč. 2012, č. 2012 (2012), s. 932838 ISSN 1942-0900 R&D Projects: GA ČR(CZ) GAP302/10/0346; GA ČR(CZ) GPP304/10/P204 Institutional support: RVO:67985823 Keywords : beta cells * reactive oxygen species homeostasis * mitochondria Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 3.393, year: 2012

Carriers of loss-of-function mutations in EXT display impaired pancreatic beta-cell reserve due to smaller pancreas volume.

Directory of Open Access Journals (Sweden)

Sophie J Bernelot Moens

Full Text Available Exotosin (EXT proteins are involved in the chain elongation step of heparan sulfate (HS biosynthesis, which is intricately involved in organ development. Loss of function mutations (LOF in EXT1 and EXT2 result in hereditary exostoses (HME. Interestingly, HS plays a role in pancreas development and beta-cell function, and genetic variations in EXT2 are associated with an increased risk for type 2 diabetes mellitus. We hypothesized that loss of function of EXT1 or EXT2 in subjects with hereditary multiple exostoses (HME affects pancreatic insulin secretion capacity and development. We performed an oral glucose tolerance test (OGTT followed by hyperglycemic clamps to investigate first-phase glucose-stimulated insulin secretion (GSIS in HME patients and age and gender matched non-affected relatives. Pancreas volume was assessed with magnetic resonance imaging (MRI. OGTT did not reveal significant differences in glucose disposal, but there was a markedly lower GSIS in HME subjects during hyperglycemic clamp (iAUC HME: 0.72 [0.46-1.16] vs. controls 1.53 [0.69-3.36] nmol·l-1·min-1, p<0.05. Maximal insulin response following arginine challenge was also significantly attenuated (iAUC HME: 7.14 [4.22-10.5] vs. controls 10.2 [7.91-12.70] nmol·l-1·min-1 p<0.05, indicative of an impaired beta-cell reserve. MRI revealed a significantly smaller pancreatic volume in HME subjects (HME: 72.0±15.8 vs. controls 96.5±26.0 cm3 p = 0.04. In conclusion, loss of function of EXT proteins may affect beta-cell mass and insulin secretion capacity in humans, and render subjects at a higher risk of developing type 2 diabetes when exposed to environmental risk factors.

Transcriptomic profiling of pancreatic alpha, beta and delta cell populations identifies delta cells as a principal target for ghrelin in mouse islets

DEFF Research Database (Denmark)

Adriaenssens, Alice E; Svendsen, Berit; Lam, Brian Y H

2016-01-01

cytometry and analysed by RNA sequencing. The role of the ghrelin receptor was validated by imaging delta cell calcium concentrations using islets with delta cell restricted expression of the calcium reporter GCaMP3, and in perfused mouse pancreases. RESULTS: A database was constructed of all genes...... expressed in alpha, beta and delta cells. The gene encoding the ghrelin receptor, Ghsr, was highlighted as being highly expressed and enriched in delta cells. Activation of the ghrelin receptor raised cytosolic calcium levels in primary pancreatic delta cells and enhanced somatostatin secretion in perfused...... pancreases, correlating with a decrease in insulin and glucagon release. The inhibition of insulin secretion by ghrelin was prevented by somatostatin receptor antagonism. CONCLUSIONS/INTERPRETATION: Our transcriptomic database of genes expressed in the principal islet cell populations will facilitate...

Pancreatic stellate cells promote epithelial-mesenchymal transition in pancreatic cancer cells

International Nuclear Information System (INIS)

Kikuta, Kazuhiro; Masamune, Atsushi; Watanabe, Takashi; Ariga, Hiroyuki; Itoh, Hiromichi; Hamada, Shin; Satoh, Kennichi; Egawa, Shinichi; Unno, Michiaki; Shimosegawa, Tooru

2010-01-01

Research highlights: → Recent studies have shown that pancreatic stellate cells (PSCs) promote the progression of pancreatic cancer. → Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and scattered, fibroblast-like appearance. → PSCs decreased the expression of epithelial markers but increased that of mesenchymal markers, along with increased migration. → This study suggests epithelial-mesenchymal transition as a novel mechanism by which PSCs contribute to the aggressive behavior of pancreatic cancer cells. -- Abstract: The interaction between pancreatic cancer cells and pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, is receiving increasing attention. There is accumulating evidence that PSCs promote the progression of pancreatic cancer by increasing cancer cell proliferation and invasion as well as by protecting them from radiation- and gemcitabine-induced apoptosis. Because epithelial-mesenchymal transition (EMT) plays a critical role in the progression of pancreatic cancer, we hypothesized that PSCs promote EMT in pancreatic cancer cells. Panc-1 and SUIT-2 pancreatic cancer cells were indirectly co-cultured with human PSCs isolated from patients undergoing operation for pancreatic cancer. The expression of epithelial and mesenchymal markers was examined by real-time PCR and immunofluorescent staining. The migration of pancreatic cancer cells was examined by scratch and two-chamber assays. Pancreatic cancer cells co-cultured with PSCs showed loose cell contacts and a scattered, fibroblast-like appearance. The expression of E-cadherin, cytokeratin 19, and membrane-associated β-catenin was decreased, whereas vimentin and Snail (Snai-1) expression was increased more in cancer cells co-cultured with PSCs than in mono-cultured cells. The migration of pancreatic cancer cells was increased by co-culture with PSCs. The PSC-induced decrease of E-cadherin expression was not altered by treatment with anti

Effect of Associated Autoimmune Diseases on Type 1 Diabetes Mellitus Incidence and Metabolic Control in Children and Adolescents

Directory of Open Access Journals (Sweden)

Aleksandra Krzewska

2016-01-01

Full Text Available Type 1 diabetes mellitus (T1DM is one of the most common chronic diseases developing in childhood. The incidence of the disease in children increases for unknown reasons at a rate from 3 to 5% every year worldwide. The background of T1DM is associated with the autoimmune process of pancreatic beta cell destruction, which leads to absolute insulin deficiency and organ damage. Complex interactions between environmental and genetic factors contribute to the development of T1DM in genetically predisposed patients. The T1DM-inducing autoimmune process can also affect other organs, resulting in development of additional autoimmune diseases in the patient, thereby impeding diabetes control. The most common T1DM comorbidities include autoimmune thyroid diseases, celiac disease, and autoimmune gastritis; additionally, diabetes can be a component of PAS (Polyglandular Autoimmune Syndrome. The aim of this review is to assess the prevalence of T1DM-associated autoimmune diseases in children and adolescents and their impact on the course of T1DM. We also present suggestions concerning screening tests.

Autoimmune pancreatitis type-1 associated with intraduct papillary mucinous neoplasm: report of two cases.

Science.gov (United States)

Vaquero, Eva C; Salcedo, Maria T; Cuatrecasas, Míriam; De León, Hannah; Merino, Xavier; Navarro, Salvador; Ginès, Angels; Abu-Suboh, Monder; Balsells, Joaquim; Fernández-Cruz, Laureano; Molero, Xavier

2014-01-01

Chronic pancreatitis lesions usually embrace both intraduct papillary mucinous neoplasm (IPMN) and pancreatic ductal adenocarcinoma (PDAC). Patients at genetically-determined high risk of PDAC often harbor IPMN and/or chronic pancreatitis, suggesting IPMN, chronic pancreatitis and PDAC may share pathogenetic mechanisms. Chronic autoimmune pancreatitis (AIP) may also herald PDAC. Concurrent IPMN and AIP have been reported in few patients. Here we describe two patients with IPMN who developed type-1 AIP fulfilling the Honolulu and Boston diagnostic criteria. AIP diffusively affected the whole pancreas, as well as peripancreatic lymph nodes and the gallbladder. Previous pancreatic resection of focal IPMN did not show features of AIP. One of the patients carried a CFTR class-I mutation. Of notice, serum IgG4 levels gradually decreased to normal values after IPMN excision. Common risk factors to IPMN and AIP may facilitate its coincidental generation. Copyright © 2014 IAP and EPC. Published by Elsevier B.V. All rights reserved.

IgG4-related disease: with emphasis on the biopsy diagnosis of autoimmune pancreatitis and sclerosing cholangitis.

Science.gov (United States)

Detlefsen, Sönke; Klöppel, Günter

2018-04-01

In 2011, chronic fibroinflammatory processes occurring simultaneously or metachronously in various organs and associated with elevated IgG4 serum levels and/or tissue infiltration with IgG4-positive plasma cells have been recognized as manifestations of a systemic disorder called IgG4-related disease (IgG4-RD). The histologic key findings are lymphoplasmacytic infiltration rich in IgG4-positive plasma cells combined with storiform fibrosis and obliterative phlebitis. Among the organs mainly affected by IgG4-RD are the pancreas and the extrahepatic bile ducts. The pancreatic and biliary alterations have been described under the terms autoimmune pancreatitis (AIP) and sclerosing cholangitis, respectively. These diseases are currently more precisely called IgG4-related pancreatitis (or type 1 AIP to distinguish it from type 2 AIP that is unrelated to IgG4-RD) and IgG4-related sclerosing cholangitis (IgG4-related SC). Clinically and grossly, both diseases commonly imitate pancreatic and biliary adenocarcinoma, tumors that are well known for their dismal prognosis. As IgG4-RD responds to steroid treatment, making a resection of a suspected tumor unnecessary, a biopsy is often required to establish the preoperative diagnosis. This review discusses the morphologic spectrum of IgG4-related pancreatitis and IgG4-related SC and focuses on the biopsy relevant histologic features for the diagnosis and differential diagnosis of these diseases.

Hybrid kappa\\lambda antibody is a new serological marker to diagnose autoimmune pancreatitis and differentiate it from pancreatic cancer.

Science.gov (United States)

Hao, Mingju; Li, Wenli; Yi, Lang; Yu, Songlin; Fan, Gaowei; Lu, Tian; Yang, Xin; Wang, Guojing; Zhang, Dong; Ding, Jiansheng; Zhang, Kuo; Zhang, Rui; Lin, Guigao; Han, Yanxi; Wang, Lunan; Li, Jinming

2016-06-08

The only generally accepted serological marker currently used for the diagnosis of autoimmune pancreatitis (AIP) is IgG4. Our aim was mainly to determine whether hybrid κ\\λ antibody can help to diagnose AIP and to differentiate it from pancreatic cancer. We established an enzyme-linked immunosorbent assay (ELISA) system to measure the levels of hybrid κ\\λ antibodies in human sera. Sera were obtained from 338 patients, including 61 with AIP, 74 with pancreatic cancer, 50 with acute pancreatitis, 40 with ordinary chronic pancreatitis, 15 with miscellaneous pancreatic diseases, and 98 with normal pancreas. Our study showed levels of hybrid κ\\λ antibodies in the AIP group were significantly higher than in the non-AIP group (P < 0.001). The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the diagnosis of AIP were 80.3%, 91%, 66.2% and 95.5% respectively. Furthermore, the combined measurement of serum hybrid κ\\λ antibody and IgG4 tended to increase the sensitivity although the difference was not statistically significant (90.2% vs. 78.7%, P = 0.08), compared to measurement of IgG4 alone. Our findings suggest that hybrid κ\\λ antibody could be a new serological marker to diagnose AIP and differentiate it from pancreatic cancer.

The physiology of rodent beta-cells in pancreas slices.

Science.gov (United States)

Rupnik, M

2009-01-01

Beta-cells in pancreatic islets form complex syncytia. Sufficient cell-to-cell electrical coupling seems to ensure coordinated depolarization pattern and insulin release that can be further modulated by rich innervation. The complex structure and coordinated action develop after birth during fast proliferation of the endocrine tissue. These emergent properties can be lost due to various reasons later in life and can lead to glucose intolerance and diabetes mellitus. Pancreas slice is a novel method of choice to study the physiology of beta-cells still embedded in their normal cellulo-social context. I present major advantages, list drawbacks and provide an overview on recent advances in our understanding of the physiology of beta-cells using the pancreas slice approach.

Protein-Mediated Interactions of Pancreatic Islet Cells

Directory of Open Access Journals (Sweden)

Paolo Meda

2013-01-01

Full Text Available The islets of Langerhans collectively form the endocrine pancreas, the organ that is soley responsible for insulin secretion in mammals, and which plays a prominent role in the control of circulating glucose and metabolism. Normal function of these islets implies the coordination of different types of endocrine cells, noticeably of the beta cells which produce insulin. Given that an appropriate secretion of this hormone is vital to the organism, a number of mechanisms have been selected during evolution, which now converge to coordinate beta cell functions. Among these, several mechanisms depend on different families of integral membrane proteins, which ensure direct (cadherins, N-CAM, occludin, and claudins and paracrine communications (pannexins between beta cells, and between these cells and the other islet cell types. Also, other proteins (integrins provide communication of the different islet cell types with the materials that form the islet basal laminae and extracellular matrix. Here, we review what is known about these proteins and their signaling in pancreatic β-cells, with particular emphasis on the signaling provided by Cx36, given that this is the integral membrane protein involved in cell-to-cell communication, which has so far been mostly investigated for effects on beta cell functions.

Cdk5 inhibitory peptide (CIP inhibits Cdk5/p25 activity induced by high glucose in pancreatic beta cells and recovers insulin secretion from p25 damage.

Directory of Open Access Journals (Sweden)

Ya-Li Zheng

Full Text Available Cdk5/p25 hyperactivity has been demonstrated to lead to neuron apoptosis and degenerations. Chronic exposure to high glucose (HG results in hyperactivity of Cdk5 and reduced insulin secretion. Here, we set out to determine whether abnormal upregulation of Cdk5/p25 activity may be induced in a pancreatic beta cell line, Min6 cells. We first confirmed that p25 were induced in overexpressed p35 cells treated with HG and increased time course dependence. Next, we showed that no p25 was detected under short time HG stimulation (4-12 hrs, however was detectable in the long exposure in HG cells (24 hrs and 48 hrs. Cdk5 activity in the above cells was much higher than low glucose treated cells and resulted in more than 50% inhibition of insulin secretion. We confirmed these results by overexpression of p25 in Min6 cells. As in cortical neurons, CIP, a small peptide, inhibited Cdk5/p25 activity and restored insulin secretion. The same results were detected in co-infection of dominant negative Cdk5 (DNCdk5 with p25. CIP also reduced beta cells apoptosis induced by Cdk5/p25. These studies indicate that Cdk5/p25 hyperactivation deregulates insulin secretion and induces cell death in pancreatic beta cells and suggests that CIP may serve as a therapeutic agent for type 2 diabetes.

Knowledge Gaps in Rodent Pancreas Biology: Taking Human Pluripotent Stem Cell-Derived Pancreatic Beta Cells into Our Own Hands.

Science.gov (United States)

Santosa, Munirah Mohamad; Low, Blaise Su Jun; Pek, Nicole Min Qian; Teo, Adrian Kee Keong

2015-01-01

In the field of stem cell biology and diabetes, we and others seek to derive mature and functional human pancreatic β cells for disease modeling and cell replacement therapy. Traditionally, knowledge gathered from rodents is extended to human pancreas developmental biology research involving human pluripotent stem cells (hPSCs). While much has been learnt from rodent pancreas biology in the early steps toward Pdx1(+) pancreatic progenitors, much less is known about the transition toward Ngn3(+) pancreatic endocrine progenitors. Essentially, the later steps of pancreatic β cell development and maturation remain elusive to date. As a result, the most recent advances in the stem cell and diabetes field have relied upon combinatorial testing of numerous growth factors and chemical compounds in an arbitrary trial-and-error fashion to derive mature and functional human pancreatic β cells from hPSCs. Although this hit-or-miss approach appears to have made some headway in maturing human pancreatic β cells in vitro, its underlying biology is vaguely understood. Therefore, in this mini-review, we discuss some of these late-stage signaling pathways that are involved in human pancreatic β cell differentiation and highlight our current understanding of their relevance in rodent pancreas biology. Our efforts here unravel several novel signaling pathways that can be further studied to shed light on unexplored aspects of rodent pancreas biology. New investigations into these signaling pathways are expected to advance our knowledge in human pancreas developmental biology and to aid in the translation of stem cell biology in the context of diabetes treatments.

IFN-beta inhibits T cell activation capacity of central nervous system APCs

DEFF Research Database (Denmark)

Teige, Ingrid; Liu, Yawei; Issazadeh-Navikas, Shohreh

2006-01-01

We have previously investigated the physiological effects of IFN-beta on chronic CNS inflammation and shown that IFN-beta(-/-) mice develop a more severe experimental autoimmune encephalomyelitis than their IFN-beta(+/-) littermates. This result was shown to be associated with a higher activation...... state of the glial cells and a higher T cell cytokine production in the CNS. Because this state suggested a down-regulatory effect of IFN-beta on CNS-specific APCs, these results were investigated further. We report that IFN-beta pretreatment of astrocytes and microglia (glial cells) indeed down......-modulate their capacity to activate autoreactive Th1 cells. First, we investigated the intrinsic ability of glial cells as APCs and report that glial cells prevent autoreactive Th1 cells expansion while maintaining Ag-specific T cell effector functions. However, when the glial cells are treated with IFN-beta before...

β-Cell regeneration through the transdifferentiation of pancreatic cells: Pancreatic progenitor cells in the pancreas.

Science.gov (United States)

Kim, Hyo-Sup; Lee, Moon-Kyu

2016-05-01

Pancreatic progenitor cell research has been in the spotlight, as these cells have the potential to replace pancreatic β-cells for the treatment of type 1 and 2 diabetic patients with the absence or reduction of pancreatic β-cells. During the past few decades, the successful treatment of diabetes through transplantation of the whole pancreas or isolated islets has nearly been achieved. However, novel sources of pancreatic islets or insulin-producing cells are required to provide sufficient amounts of donor tissues. To overcome this limitation, the use of pancreatic progenitor cells is gaining more attention. In particular, pancreatic exocrine cells, such as duct epithelial cells and acinar cells, are attractive candidates for β-cell regeneration because of their differentiation potential and pancreatic lineage characteristics. It has been assumed that β-cell neogenesis from pancreatic progenitor cells could occur in pancreatic ducts in the postnatal stage. Several studies have shown that insulin-producing cells can arise in the duct tissue of the adult pancreas. Acinar cells also might have the potential to differentiate into insulin-producing cells. The present review summarizes recent progress in research on the transdifferentiation of pancreatic exocrine cells into insulin-producing cells, especially duct and acinar cells.

Glucose activates prenyltransferases in pancreatic islet {beta}-cells

Energy Technology Data Exchange (ETDEWEB)

Goalstone, Marc [Department of Medicine, University of Colorado, VA Medical Center, Denver, CO 80220 (United States); Kamath, Vasudeva [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States); Kowluru, Anjaneyulu, E-mail: akowluru@med.wayne.edu [Department of Pharmaceutical Sciences, Wayne State University, VA Medical Center, Detroit, MI 48201 (United States)

2010-01-01

A growing body of evidence implicates small G-proteins [e.g., Cdc42 and Rac1] in glucose-stimulated insulin secretion [GSIS] in the islet {beta}-cell. These signaling proteins undergo post-translational modifications [e.g., prenylation] at their C-terminal cysteine residue and appear to be essential for the transport and fusion of insulin-containing secretory granules with the plasma membrane and the exocytotic secretion of insulin. However, potential regulation of the prenylating enzymes by physiological insulin secretogues [e.g., glucose] has not been investigated thus far. Herein, we report immunological localization, sub-cellular distribution and regulation of farnesyltransferases [FTases] and geranylgeranyltransferase [GGTase] by glucose in insulin-secreting INS 832/13 {beta}-cells and normal rat islets. Our findings suggest that an insulinotropic concentration of glucose [20 mM] markedly stimulated the expression of the {alpha}-subunits of FTase/GGTase-1, but not the {beta}-subunits of FTase or GGTase-1 without significantly affecting the predominantly cytosolic distribution of these holoenzymes in INS 832/13 cells and rodent islets. Under these conditions, glucose significantly stimulated [2.5- to 4.0-fold over basal] the activities of both FTase and GGTase-1 in both cell types. Together, these findings provide the first evidence to suggest that GSIS involves activation of the endogenous islet prenyltransferases by glucose, culminating in the activation of their respective G-protein substrates, which is necessary for cytoskeletal rearrangement, vesicular transport, fusion and secretion of insulin.

Pancreatic beta-cell lipotoxicity induced by overexpression of hormone-sensitive lipase

DEFF Research Database (Denmark)

Winzell, Maria Sörhede; Svensson, Håkan; Enerbäck, Sven

2003-01-01

Lipid perturbations associated with triglyceride overstorage in beta-cells impair insulin secretion, a process termed lipotoxicity. To assess the role of hormone-sensitive lipase, which is expressed and enzymatically active in beta-cells, in the development of lipotoxicity, we generated transgenic...... mice overexpressing hormone-sensitive lipase specifically in beta-cells. Transgenic mice developed glucose intolerance and severely blunted glucose-stimulated insulin secretion when challenged with a high-fat diet. As expected, both lipase activity and forskolin-stimulated lipolysis was increased...

Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

Energy Technology Data Exchange (ETDEWEB)

Kover, Karen, E-mail: kkover@cmh.edu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States); Tasch, James; Hager, Melissa [Kansas City University Medical Biosciences, Kansas City, MO (United States); Clements, Mark; Moore, Wayne V. [Division of Endocrine/Diabetes, Children' s Mercy Hospital & Clinics, Kansas City, MO 64108 (United States); University of Missouri-Kansas City School of Medicine, Kansas City, MO 64108 (United States)

2015-06-19

Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H{sub 2}O{sub 2} assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H{sub 2}O{sub 2} levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose

Osteocalcin protects pancreatic beta cell function and survival under high glucose conditions

International Nuclear Information System (INIS)

Kover, Karen; Yan, Yun; Tong, Pei Ying; Watkins, Dara; Li, Xiaoyu; Tasch, James; Hager, Melissa; Clements, Mark; Moore, Wayne V.

2015-01-01

Diabetes is characterized by progressive beta cell dysfunction and loss due in part to oxidative stress that occurs from gluco/lipotoxicity. Treatments that directly protect beta cell function and survival in the diabetic milieu are of particular interest. A growing body of evidence suggests that osteocalcin, an abundant non-collagenous protein of bone, supports beta cell function and proliferation. Based on previous gene expression data by microarray, we hypothesized that osteocalcin protects beta cells from glucose-induced oxidative stress. To test our hypothesis we cultured isolated rat islets and INS-1E cells in the presence of normal, high, or high glucose ± osteocalcin for up to 72 h. Oxidative stress and viability/mitochondrial function were measured by H 2 O 2 assay and Alamar Blue assay, respectively. Caspase 3/7 activity was also measured as a marker of apoptosis. A functional test, glucose stimulated insulin release, was conducted and expression of genes/protein was measured by qRT-PCR/western blot/ELISA. Osteocalcin treatment significantly reduced high glucose-induced H 2 O 2 levels while maintaining viability/mitochondrial function. Osteocalcin also significantly improved glucose stimulated insulin secretion and insulin content in rat islets after 48 h of high glucose exposure compared to untreated islets. As expected sustained high glucose down-regulated gene/protein expression of INS1 and BCL2 while increasing TXNIP expression. Interestingly, osteocalcin treatment reversed the effects of high glucose on gene/protein expression. We conclude that osteocalcin can protect beta cells from the negative effects of glucose-induced oxidative stress, in part, by reducing TXNIP expression, thereby preserving beta cell function and survival. - Highlights: • Osteocalcin reduces glucose-induced oxidative stress in beta cells. • Osteocalcin preserves beta cell function and survival under stress conditions. • Osteocalcin reduces glucose-induced TXNIP

Resolution of alloimmunization and refractory autoimmune hemolytic anemia in a multi-transfused beta-thalassemia major patient

Directory of Open Access Journals (Sweden)

Joseph Philip

2014-01-01

Full Text Available Beta-thalassemia is one of the most prevalent autosomal disorders, which affect more than 400,000 newborn per year worldwide. In India, the carrier rate of beta-thalassemia varies from 3-17%. The overall rate of alloimmunization in thalassemia patients has been reported to be 5-30% in the world, which is mostly contributed by the alloimmunization to minor blood group antigen. Among Asians, the incidence of red cell alloimmunization is 22%. The recommended treatment for beta-thalassemia major is regular blood transfusion every 3 to 4 weeks. The development of anti-red cell antibodies (alloantibodies and/or autoantibodies can significantly complicate transfusion therapy. Alloantibodies are commonly associated with red cell hemolysis. Red cell autoantibodies appear less frequently, but they can result in clinical hemolysis called autoimmune hemolytic anemia (AIHA, and in difficulty in cross-matching blood. Patients with autoantibodies may have a higher transfusion rate and often require immunosuppressive drugs or alternative treatments including intravenous immunoglobulin (IVIg and rituximab (anti-CD20 monoclonal antibody.

Hypoglycemic and beta cell protective effects of andrographolide analogue for diabetes treatment

Directory of Open Access Journals (Sweden)

Larrick James W

2009-07-01

Full Text Available Abstract Background While all anti-diabetic agents can decrease blood glucose level directly or indirectly, few are able to protect and preserve both pancreatic beta cell mass and their insulin-secreting functions. Thus, there is an urgent need to find an agent or combination of agents that can lower blood glucose and preserve pancreatic beta cells at the same time. Herein, we report a dual-functional andrographolide-lipoic acid conjugate (AL-1. The anti-diabetic and beta cell protective activities of this novel andrographolide-lipoic acid conjugate were investigated. Methods In alloxan-treated mice (a model of type 1 diabetes, drugs were administered orally once daily for 6 days post-alloxan treatment. Fasting blood glucose and serum insulin were determined. Pathologic and immunohistochemical analysis of pancreatic islets were performed. Translocation of glucose transporter subtype 4 in soleus muscle was detected by western blot. In RIN-m cells in vitro, the effect of AL-1 on H2O2-induced damage and reactive oxidative species production stimulated by high glucose and glibenclamide were measured. Inhibition of nuclear factor kappa B (NF-κB activation induced by IL-1β and IFN-γ was investigated. Results In alloxan-induced diabetic mouse model, AL-1 lowered blood glucose, increased insulin and prevented loss of beta cells and their dysfunction, stimulated glucose transport protein subtype 4 (GLUT4 membrane translocation in soleus muscles. Pretreatment of RIN-m cells with AL-1 prevented H2O2-induced cellular damage, quenched glucose and glibenclamide-stimulated reactive oxidative species production, and inhibited cytokine-stimulated NF-κB activation. Conclusion We have demonstrated that AL-1 had both hypoglycemic and beta cell protective effects which translated into antioxidant and NF-κB inhibitory activity. AL-1 is a potential new anti-diabetic agent.

Dynamics and Synchrony of Pancreatic beta-cells and Islets

DEFF Research Database (Denmark)

Pedersen, Morten Gram

2006-01-01

description of these processes and their interactions would provide important input in the search for a better treatment of the disease. The thesis describes several aspects of mathematical modeling of beta-cells relevant for the understanding of glucose stimulated insulin secretion. It consists...... and the synchronized behavior of many coupled beta-cells as well as to the synchrony of islets. Rather than developing new biophysical models, the thesis investigates existing models, their integration and simplifications, and analyzed the corresponding dynamics, in order to use these models for investigating...

Morphological and immunohistochemical comparison of intrapancreatic nerves between chronic pancreatitis and type 1 autoimmune pancreatitis.

Science.gov (United States)

Kato, Kota; Ikeura, Tsukasa; Yanagawa, Masato; Tomiyama, Takashi; Fukui, Toshiro; Uchida, Kazushige; Takaoka, Makoto; Nishio, Akiyoshi; Uemura, Yoshiko; Satoi, Sohei; Yamada, Hisao; Okazaki, Kazuichi

The abdominal pain associated with chronic pancreatitis (CP) may be related to the increased number and size of intrapancreatic nerves. On the other hand, patients with type 1 autoimmune pancreatitis (AIP) rarely suffer from the pain syndrome, and there are no previous studies concerning the histopathological findings of intrapancreatic nerves in patients with type 1 AIP. The current study is aimed at investigating the differences in the histopathological and immunohistochemical findings of intrapancreatic nerves in patients with CP and type 1 AIP. Neuroanatomical differences between CP and type 1 AIP were assessed by immunostaining with a pan-neuronal marker, protein gene product 9.5 (PGP9.5). The number (neural density) and area (neural hypertrophy) of PGP9.5-immunopositive nerves were quantitatively analyzed. Furthermore, the expression of nerve growth factor (NGF), and a high affinity receptor for NGF, tyrosine kinase receptor A (TrkA), was assessed by immunohistochemistry. Both neural density and hypertrophy were significantly greater in pancreatic tissue samples from patients with CP than those with normal pancreas or type 1 AIP. NGF expression was stronger in type 1 AIP than in CP, whereas TrkA expression in type 1 AIP was poorer than in CP. Although CP and type 1 AIP are both characterized by the presence of sustained pancreatic inflammation, they are different in terms of the density and hypertrophy of intrapancreatic nerve fibers. It is possible that this may be related to the difference in the activity of the NGF/TrkA-pathway between the two types of pancreatitis. Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.

Differentiation of focal-type autoimmune pancreatitis from pancreatic carcinoma: assessment by multiphase contrast-enhanced CT

Energy Technology Data Exchange (ETDEWEB)

Furuhashi, Naohiro; Suzuki, Kojiro; Sakurai, Yusuke; Naganawa, Shinji [Nagoya University Graduate School of Medicine, Department of Radiology, Nagoya (Japan); Ikeda, Mitsuru [Nagoya University Graduate School of Medicine, Department of Radiological Technology, Nagoya (Japan); Kawai, Yuichi [Japanese Red Cross Nagoya Daiichi Hospital, Department of Diagnostic Radiology, Nagoya (Japan)

2015-05-01

To evaluate the utility of multiphase contrast-enhanced computed tomography (CT) findings alone and in combination for differentiating focal-type autoimmune pancreatitis (f-AIP) from pancreatic carcinoma (PC). The study group comprised 22 f-AIP lesions and 61 PC lesions. Two radiologists independently evaluated CT findings. Frequencies of findings were compared between f-AIP and PC. Statistical, univariate and multivariate analyses were performed. Homogeneous enhancement during the portal phase (AIP, 59 % vs. PC, 3 %; P < 0.001), dotted enhancement during the pancreatic phase (50 % vs. 7 %; P < 0.001), duct-penetrating sign (46 % vs. 2 %; P < 0.001), enhanced duct sign (36 % vs. 2 %; P < 0.001) and capsule-like rim (46 % vs. 3 %; P < 0.001) were more frequently observed in AIP. Ring-like enhancement during the delayed phase (5 % vs. 46 %; P < 0.001) and peripancreatic strands with a length of at least 10 mm (5 % vs. 39 %; P = 0.001) were more frequently observed in PC. AIP was identified with 82 % sensitivity and 98 % specificity using four of these seven findings. Multivariate analysis revealed significant differences in dotted enhancement (P = 0.004), duct-penetrating sign (P < 0.001) and capsule-like rim (P = 0.007). The combination of CT findings may allow improvements in differentiating f-AIP from PC. (orig.)

Insulin autoimmune syndrome: case report

Directory of Open Access Journals (Sweden)

Rodrigo Oliveira Moreira

Full Text Available CONTEXT: Insulin autoimmune syndrome (IAS, Hirata disease is a rare cause of hypoglycemia in Western countries. It is characterized by hypoglycemic episodes, elevated insulin levels, and positive insulin antibodies. Our objective is to report a case of IAS identified in South America. CASE REPORT: A 56-year-old Caucasian male patient started presenting neuroglycopenic symptoms during hospitalization due to severe trauma. Biochemical evaluation confirmed hypoglycemia and abnormally high levels of insulin. Conventional imaging examinations were negative for pancreatic tumor. Insulin antibodies were above the normal range. Clinical remission of the episodes was not achieved with verapamil and steroids. Thus, a subtotal pancreatectomy was performed due to the lack of response to conservative treatment and because immunosuppressants were contraindicated due to bacteremia. Histopathological examination revealed diffuse hypertrophy of beta cells. The patient continues to have high insulin levels but is almost free of hypoglycemic episodes.

Adipose Tissue-Derived Mesenchymal Stem Cells Exert In Vitro Immunomodulatory and Beta Cell Protective Functions in Streptozotocin-Induced Diabetic Mice Model

Directory of Open Access Journals (Sweden)

Hossein Rahavi

2015-01-01

Full Text Available Regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs might be applied for type 1 diabetes mellitus (T1DM treatment. Thus, we proposed in vitro assessment of adipose tissue-derived MSCs (AT-MSCs immunomodulation on autoimmune response along with beta cell protection in streptozotocin- (STZ- induced diabetic C57BL/6 mice model. MSCs were extracted from abdominal adipose tissue of normal mice and cultured to proliferate. Diabetic mice were prepared by administration of multiple low-doses of streptozotocin. Pancreatic islets were isolated from normal mice and splenocytes prepared from normal and diabetic mice. Proliferation, cytokine production, and insulin secretion assays were performed in coculture experiments. AT-MSCs inhibited splenocytes proliferative response to specific (islet lysate and nonspecific (PHA triggers in a dose-dependent manner (P<0.05. Decreased production of proinflammatory cytokines, such as IFN-γ, IL-2, and IL-17, and increased secretion of regulatory cytokines such as TGF-β, IL-4, IL-10, and IL-13 by stimulated splenocytes were also shown in response to islet lysate or PHA stimulants (P<0.05. Finally, we demonstrated that AT-MSCs could effectively sustain viability as well as insulin secretion potential of pancreatic islets in the presence of reactive splenocytes (P<0.05. In conclusion, it seems that MSCs may provide a new horizon for T1DM cell therapy and islet transplantation in the future.

Profile of blood glucose and ultrastucture of beta cells pancreatic islet in alloxan compound induced rats

Directory of Open Access Journals (Sweden)

I Nyoman Suarsana

2010-06-01

Full Text Available Diabetes is marked by elevated levels of blood glucose, and progressive changes of the structure of pancreatic islet histopathology. The objective of this research was to analyse the glucose level and histophatological feature in pancreatic islet in alloxan compound induced rats. A total of ten male Spraque Dawley rats of 2 months old were used in this study. The rats were divided into two groups: (1 negative control group (K-, and (2 positif induced alloxan group (diabetic group =DM. The rats were induced by a single dose intraperitonial injection of alloxan compound 120 mg/kg of body weight. The treatment was conducted for 28 days. Blood glucose levels of rats were analysed at 0, 4, 7, 14, 21, and 28 days following treatment. At the end of the experiment, rats were sacrificed by cervical dislocation. Pancreas was collected for analysis of histopathological study by Immunohistochemical technique, and ultrastructural study using transmission electron microscope (TEM. The result showed that Langerhans islet of diabetic rat (rat of DM group showed a marked reduction of size, number of Langerhans islet of diabetic rat decrease, and characterized by hyperglycemic condition. By using TEM, beta cells of DM group showed the rupture of mitochondrial membrane, the lost of cisternal structure of inner membrane of mitocondria, reduction of insulin secretory granules, linkage between cells acinar with free Langerhans islet, and the caryopicnotic of nucleus.

A Rare Multifocal Pattern of Type 2 Autoimmune Pancreatitis with Negative IgG4: A Potential Diagnostic Pitfall That May Mimic Multifocal Pancreatic Adenocarcinoma

Directory of Open Access Journals (Sweden)

Partha Hota

2018-02-01

Full Text Available Autoimmune pancreatitis (AIP is an increasingly recognized form of acute pancreatitis characterized by obstructive jaundice with a rapid and dramatic treatment response to steroid therapy. Recently, AIP has been divided into two distinct phenotypes: lymphoplasmocytic sclerosing pancreatitis AIP (type 1 and idiopathic duct-centric pancreatitis AIP (type 2; each of which have their own distinct demographics, diagnostic criteria, and histopathological features. We report, to the best of our knowledge, the first case of a multifocal pattern of type 2 AIP characterized with both CT and MR imaging. This rare imaging pattern of AIP may mimic the appearance of more worrisome malignant etiologies such as multifocal pancreatic adenocarcinoma or lymphoma, with overlapping imaging characteristics potentially complicating or delaying diagnosis. Therefore, recognition of this atypical pattern of AIP and avoidance of this potential diagnostic pitfall is crucial.

Alterations in integrin expression modulates invasion of pancreatic cancer cells.

LENUS (Irish Health Repository)

Walsh, Naomi

2009-01-01

BACKGROUND: Factors mediating the invasion of pancreatic cancer cells through the extracellular matrix (ECM) are not fully understood. METHODS: In this study, sub-populations of the human pancreatic cancer cell line, MiaPaCa-2 were established which displayed differences in invasion, adhesion, anoikis, anchorage-independent growth and integrin expression. RESULTS: Clone #3 displayed higher invasion with less adhesion, while Clone #8 was less invasive with increased adhesion to ECM proteins compared to MiaPaCa-2. Clone #8 was more sensitive to anoikis than Clone #3 and MiaPaCa-2, and displayed low colony-forming efficiency in an anchorage-independent growth assay. Integrins beta 1, alpha 5 and alpha 6 were over-expressed in Clone #8. Using small interfering RNA (siRNA), integrin beta1 knockdown in Clone #8 cells increased invasion through matrigel and fibronectin, increased motility, decreased adhesion and anoikis. Integrin alpha 5 and alpha 6 knockdown also resulted in increased motility, invasion through matrigel and decreased adhesion. CONCLUSION: Our results suggest that altered expression of integrins interacting with different extracellular matrixes may play a significant role in suppressing the aggressive invasive phenotype. Analysis of these clonal populations of MiaPaCa-2 provides a model for investigations into the invasive properties of pancreatic carcinoma.

[Associations of insulin resistance and pancreatic beta-cell function with plasma glucose level in type 2 diabetes].

Science.gov (United States)

Nian, Xiaoping; Sun, Gaisheng; Dou, Chunmei; Hou, Hongbo; Fan, Xiuping; Yu, Hongmei; Ma, Ling; He, Bingxian

2002-06-10

To investigate the influence of insulin resistance and pancreatic beta-cell function on plasma glucose level in type 2 diabetes so as to provide theoretical basis for reasonable selection of hypoglycemic agents. The plasma non-specific insulin (NSINS), true insulin (TI) and glucose in eight-one type 2 diabetics, 38 males and 43 females, with a mean age of 53 years, were examined 0, 30, 60 and 120 minutes after they had 75 grams of instant noodles. The patients were divided into two groups according to their fasting plasma glucose (FPG): group A (FPG = 8.89 mmol/L). The insulin resistance was evaluated by HOMA-IR, the beta-cell function was evaluated by HOMA-beta formula and the formula deltaI(30)/deltaG(30) = (deltaI(30)-deltaI(0))/(deltaG(30)-deltaG(0)). The insulin area under curve (INSAUC) was evaluated by the formula INSAUC=FINS/2+INS(30)+INS(60)+INS(120)/2. The mean FPG was 6.23 mmol/L in group A and 12.6 mmol/L in group B. PG2H was 11.7 mmol/L in group A and 19.2 mmol/L in group B. The TI levels in group B at 0, 30, 60, 120 min during standard meal test were significantly higher than those in group A: 6.15 +/- 1.06 vs 4.77 +/- 1.06, 9.76 +/- 1.1 vs 5.88 +/- 1.1,14.68 +/- 1.11 vs 6.87 +/- 1.1 and 17.13 +/- 1.12 vs 8.0 +/- 1.1 microU/dl (all P< 0.01). The NSINS showed the same trend. The insulin resistance in group B was 1.5 times that in group A. With the insulin resistance adjusted, the beta cell function in group A was 5 to 6 times that in group B. The INSAUC in group A was 1.66 times larger than that in group B, especially the INSAUC for true insulin (2 times larger). The contribution of insulin resistance and beta cell function to PG2H was half by half in group A and 1:8 in group B. beta cell function calculated by insulin (Homa-beta) explained 41% of the plasma glucose changes in group A and 54% of the plasma glucose changes in group B. The contribution of insulin deficiency to plasma glocose was 3.3.times that of insulin resistance in group A and was 9

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

International Nuclear Information System (INIS)

Kawai, Yuichi; Suzuki, Kojiro; Itoh, Shigeki; Takada, Akira; Mori, Yoshine; Naganawa, Shinji

2012-01-01

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the “enhanced duct sign”, for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Autoimmune pancreatitis: Assessment of the enhanced duct sign on multiphase contrast-enhanced computed tomography

Energy Technology Data Exchange (ETDEWEB)

Kawai, Yuichi, E-mail: kawai.yuichi@a.mbox.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Suzuki, Kojiro, E-mail: kojiro@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Itoh, Shigeki, E-mail: shigeito@nagoya-1st.jrc.or.jp [Department of Diagnostic Radiology, Japan Red Cross Nagoya Daiichi Hospital, 3-35 Michishita-cho, Nakamura-ku, Nagoya 453-8511 (Japan); Takada, Akira, E-mail: takadaa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Mori, Yoshine, E-mail: yoshine@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Naganawa, Shinji, E-mail: naganawa@med.nagoya-u.ac.jp [Department of Radiology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan)

2012-11-15

Purpose: To assess the usefulness of the computed tomography (CT) finding of main pancreatic duct (MPD) wall enhancement, termed the 'enhanced duct sign', for diagnosis of autoimmune pancreatitis (AIP) in comparison with diagnosis of pancreatic carcinoma and chronic pancreatitis. Materials and methods: Two radiologists independently evaluated the presence or absence of the enhanced duct sign on multiphase contrast-enhanced CT in patients with AIP (n = 55), pancreatic carcinoma (n = 50), and chronic pancreatitis (n = 50). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of AIP were calculated. In patients demonstrating the enhanced duct sign, additional findings were evaluated by consensus. Results: The enhanced duct sign was more frequently observed in patients with AIP (37/55, 67%) than in patients with pancreatic carcinoma (5/50, 10%) or chronic pancreatitis (0/50, 0%) (P < 0.05). The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the finding were 0.67, 0.95, 0.85, 0.88, and 0.84, respectively. In AIP, the lumen within the enhanced duct was completely or partially invisible in 29 of 37 (78%) patients, and the enhanced duct was observed within the affected pancreatic parenchyma in 35 of 37 (95%) patients. In pancreatic carcinoma, the lumen within the enhanced duct was visible in all patients (5/5, 100%), and the enhanced duct was observed downstream of the tumor (5/5, 100%). Conclusion: The enhanced duct sign is highly specific of AIP.

Visualizing pancreatic {beta}-cell mass with [{sup 11}C]DTBZ

Energy Technology Data Exchange (ETDEWEB)

Simpson, Norman Ray [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Souza, Fabiola [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Witkowski, Piotr [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Maffei, Antonella [Institute of Genetics and Biophysics ' Adriano Buzzati-Traverso' , CNR, Naples 80131 (Italy); Raffo, Anthony [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Herron, Alan [Center for Comparative Medicine and The Department of Pathology, Baylor College of Medicine, Houston, TX 77030 (United States); Kilbourn, Michael [Department of Radiology, University of Michigan, Ann Arbor, MI 48109-0638 (United States); Jurewicz, Agata [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Herold, Kevan [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States); Liu, Eric [Diabetes Branch, NIDDK, National Institutes of Health, Bethesda, MD 20854 (United States); Hardy, Mark Adam [Department of Medicine, Columbia University Medical School, New York, NY 10032 (United States); Van Heertum, Ronald [Department of Radiology, Columbia University Medical School, New York, NY 10032 (United States); Harris, Paul Emerson [Department of Surgery, Columbia University Medical School, New York, NY 10032 (United States)]. E-mail: peh1@columbia.edu

2006-10-15

{beta}-Cell mass (BCM) influences the total amount of insulin secreted, varies by individual and by the degree of insulin resistance, and is affected by physiologic and pathologic conditions. The islets of Langerhans, however, appear to have a reserve capacity of insulin secretion and, overall, assessments of insulin and blood glucose levels remain poor measures of BCM, {beta}-cell function and progression of diabetes. Thus, novel noninvasive determinations of BCM are needed to provide a quantitative endpoint for novel therapies of diabetes, islet regeneration and transplantation. Built on previous gene expression studies, we tested the hypothesis that the targeting of vesicular monoamine transporter 2 (VMAT2), which is expressed by {beta} cells, with [{sup 11}C]dihydrotetrabenazine ([{sup 11}C]DTBZ), a radioligand specific for VMAT2, and the use of positron emission tomography (PET) can provide a measure of BCM. In this report, we demonstrate decreased radioligand uptake within the pancreas of Lewis rats with streptozotocin-induced diabetes relative to their euglycemic historical controls. These studies suggest that quantitation of VMAT2 expression in {beta} cells with the use of [{sup 11}C]DTBZ and PET represents a method for noninvasive longitudinal estimates of changes in BCM that may be useful in the study and treatment of diabetes.

Subclassification of autoimmune pancreatitis: a histologic classification with clinical significance.

Science.gov (United States)

Deshpande, Vikram; Gupta, Rajib; Sainani, Nisha; Sahani, Dushyant V; Virk, Renu; Ferrone, Cristina; Khosroshahi, Arezou; Stone, John H; Lauwers, Gregory Y

2011-01-01

Autoimmune pancreatitis (AIP) is a chronic inflammatory disease of the pancreas. Examination of pancreatic resection specimens from patients with AIP has shown that there are 2 subclasses of this disease. However, there is no widely accepted pathologic classification scheme and the clinical significance of such a classification remains to be established. In this study, we revisited the subclassification of AIP and examine whether this provides clinically and prognostically meaningful information. We evaluated 29 pancreatic resection specimens from patients with AIP. Demographic, clinical, and imaging data were recorded, as was evidence of extrapancreatic manifestations. In addition to a detailed and semiquantitative histologic evaluation, immunohistochemistry for IgG4 was performed on pancreatic and extrapancreatic tissues. We also evaluated 48 consecutive cases of chronic pancreatitis, not otherwise specified. The resected specimens could readily be subclassified into 2 subtypes: type 1 (n=11) and type 2 (n=18). In comparison with patients with type 2 disease, patients with type 1 disease were significantly more likely to be males (P=0.09), older (P=0.02), and present with jaundice (P=0.01), and less likely to be associated with abdominal pain (P=0.04). On imaging, the pancreatic tail cut-off sign was exclusively seen in patients with type 2 disease (4 of 10 cases). Hypercellular inflamed interlobular stroma was unique to type 1 pattern (91%), whereas significant ductal injury in the form of microabscesses and ductal ulceration was almost exclusively seen in type 2 pattern (78%). Eight of 10 patients with a type 1 pattern had evidence of a systemic disease. Three patients with type 2 disease had recurrent episodes of pancreatitis after their pancreatic resection. In comparison with the cohort of chronic pancreatitis, not otherwise specified, type 2 AIP cases were less likely to be associated with a history of alcohol abuse, and showed significantly more foci of

TGF-{beta}1 increases invasiveness of SW1990 cells through Rac1/ROS/NF-{kappa}B/IL-6/MMP-2

Energy Technology Data Exchange (ETDEWEB)

Binker, Marcelo G. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina); Binker-Cosen, Andres A. [CBRHC Research Center, Buenos Aires (Argentina); Gaisano, Herbert Y. [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); Cosen, Rodica H. de [CBRHC Research Center, Buenos Aires (Argentina); Cosen-Binker, Laura I., E-mail: laura.cosen.binker@utoronto.ca [Departments of Medicine and Physiology, University of Toronto, Toronto, Ontario, Canada M5S 1A8 (Canada); CBRHC Research Center, Buenos Aires (Argentina)

2011-02-04

Research highlights: {yields} Rac1 mediates TGF-{beta}1-induced SW1990 invasion through MMP-2 secretion and activation. {yields} NADPH-generated ROS act downstream of Rac1 in TGF-{beta}1-challenged SW1990 cells. {yields} TGF-{beta}1-stimulated ROS activate NF-{kappa}B in SW1990 cells. {yields} NF{kappa}B-induced IL-6 release is required for secretion and activation of MMP-2 in SW1990 cells. -- Abstract: Human pancreatic cancer invasion and metastasis have been found to correlate with increased levels of active matrix metalloproteinase 2 (MMP-2). The multifunctional cytokine transforming growth factor beta 1 (TGF-{beta}1) has been shown to increase both secretion of MMP-2 and invasion by several pancreatic cancer cell types. In the present study, we investigated the signaling pathway involved in TGF-{beta}1-promoted MMP-2 secretion and invasion by human pancreatic cancer cells SW1990. Using specific inhibitors, we found that stimulation of these tumor cells with TGF-{beta}1 induced secretion and activation of the collagenase MMP-2, which was required for TGF-{beta}1-stimulated invasion. Our results also indicate that signaling events involved in TGF-{beta}1-enhanced SW1990 invasiveness comprehend activation of Rac1 followed by generation of reactive oxygen species through nicotinamide adenine dinucleotide phosphate-oxidase, activation of nuclear factor-kappa beta, release of interleukin-6, and secretion and activation of MMP-2.

Do post-translational beta cell protein modifications trigger type 1 diabetes?

DEFF Research Database (Denmark)

Størling, Joachim; Overgaard, Anne Julie; Brorsson, Caroline Anna

2013-01-01

beta cell-specific neo-epitopes. We suggest that the current paradigm of type 1 diabetes as a classical autoimmune disease should be reconsidered since the immune response may not be directed against native beta cell proteins. A modified model for the pathogenetic events taking place in islets leading...... diabetes exists in the published literature. Furthermore, we report that cytokines change the expression levels of several genes encoding proteins involved in PTM processes in human islets, and that there are type 1 diabetes-associated polymorphisms in a number of these. In conclusion, data from...... the literature and presented experimental data support the notion that PTM of beta cell proteins may be involved in triggering beta cell destruction in type 1 diabetes. If the beta cell antigens recognised by the immune system foremost come from modified proteins rather than native ones, the concept of type 1...

Repeated Gene Transfection Impairs the Engraftment of Transplanted Porcine Neonatal Pancreatic Cells

Directory of Open Access Journals (Sweden)

Min Koo Seo

2011-02-01

Full Text Available BackgroundPreviously, we reported that neonatal porcine pancreatic cells transfected with hepatocyte growth factor (HGF gene in an Epstein-Barr virus (EBV-based plasmid (pEBVHGF showed improved proliferation and differentiation compared to those of the control. In this study, we examined if pancreatic cells transfected repeatedly with pEBVHGF can be successfully grafted to control blood glucose in a diabetes mouse model.MethodsNeonatal porcine pancreatic cells were cultured as a monolayer and were transfected with pEBVHGF every other day for a total of three transfections. The transfected pancreatic cells were re-aggregated and transplanted into kidney capsules of diabetic nude mice or normal nude mice. Blood glucose level and body weight were measured every other day after transplantation. The engraftment of the transplanted cells and differentiation into beta cells were assessed using immunohistochemistry.ResultsRe-aggregation of the pancreatic cells before transplantation improved engraftment of the cells and facilitated neovascularization of the graft. Right before transplantation, pancreatic cells that were transfected with pEBVHGF and then re-aggregated showed ductal cell marker expression. However, ductal cells disappeared and the cells underwent fibrosis in a diabetes mouse model two to five weeks after transplantation; these mice also did not show controlled blood glucose levels. Furthermore, pancreatic cells transplanted into nude mice with normal blood glucose showed poor graft survival regardless of the type of transfected plasmid (pCEP4, pHGF, or pEBVHGF.ConclusionFor clinical application of transfected neonatal porcine pancreatic cells, further studies are required to develop methods of overcoming the damage for the cells caused by repeated transfection and to re-aggregate them into islet-like structures.

Calcium has a permissive role in interleukin-1beta-induced c-jun N-terminal kinase activation in insulin-secreting cells

DEFF Research Database (Denmark)

Størling, Joachim; Zaitsev, Sergei V; Kapelioukh, Iouri L

2005-01-01

The c-jun N-terminal kinase (JNK) signaling pathway mediates IL-1beta-induced apoptosis in insulin-secreting cells, a mechanism relevant to the destruction of pancreatic beta-cells in type 1 and 2 diabetes. However, the mechanisms that contribute to IL-1beta activation of JNK in beta-cells are la...

A Simple Matter of Life and Death—The Trials of Postnatal Beta-Cell Mass Regulation

Directory of Open Access Journals (Sweden)

Elena Tarabra

2012-01-01

Full Text Available Pancreatic beta-cells, which secrete the hormone insulin, are the key arbiters of glucose homeostasis. Defective beta-cell numbers and/or function underlie essentially all major forms of diabetes and must be restored if diabetes is to be cured. Thus, the identification of the molecular regulators of beta-cell mass and a better understanding of the processes of beta-cell differentiation and proliferation may provide further insight for the development of new therapeutic targets for diabetes. This review will focus on the principal hormones and nutrients, as well as downstream signalling pathways regulating beta-cell mass in the adult. Furthermore, we will also address more recently appreciated regulators of beta-cell mass, such as microRNAs.

Response gene to complement-32 enhances metastatic phenotype by mediating transforming growth factor beta-induced epithelial-mesenchymal transition in human pancreatic cancer cell line BxPC-3

Directory of Open Access Journals (Sweden)

Zhu Liang

2012-03-01

Full Text Available Abstract Background Response gene to complement-32 (RGC-32 is comprehensively expressed in many kinds of tissues and has been reported to be expressed abnormally in different kinds of human tumors. However, the role of RGC-32 in cancer remains controversial and no reports have described the effect of RGC-32 in pancreatic cancer. The present study investigated the expression of RGC-32 in pancreatic cancer tissues and explored the role of RGC-32 in transforming growth factor-beta (TGF-β-induced epithelial-mesenchymal transition (EMT in human pancreatic cancer cell line BxPC-3. Methods Immunohistochemical staining of RGC-32 and E-cadherin was performed on specimens from 42 patients with pancreatic cancer, 12 with chronic pancreatitis and 8 with normal pancreas. To evaluate the role of RGC-32 in TGF-β-induced EMT in pancreatic cancer cells, BxPC-3 cells were treated with TGF-β1, and RGC-32 siRNA silencing and gene overexpression were performed as well. The mRNA expression and protein expression of RGC-32 and EMT markers such E-cadherin and vimentin were determined by quantitative reverse transcription-PCR (qRT-PCR and western blot respectively. Finally, migration ability of BxPC-3 cells treated with TGF-β and RGC-32 siRNA transfection was examined by transwell cell migration assay. Results We found stronger expression of RGC-32 and higher abnormal expression rate of E-cadherin in pancreatic cancer tissues than those in chronic pancreatitis tissues and normal pancreatic tissues. Immunohistochemical analysis revealed that both RGC-32 positive expression and E-cadherin abnormal expression in pancreatic cancer were correlated with lymph node metastasis and TNM staging. In addition, a significant and positive correlation was found between positive expression of RGC-32 and abnormal expression of E-cadherin. Furthermore, in vitro, we found sustained TGF-β stimuli induced EMT and up-regulated RGC-32 expression in BxPC-3 cells. By means of si

Towards consistent generation of pancreatic lineage progenitors from human pluripotent stem cells.

Science.gov (United States)

Rostovskaya, Maria; Bredenkamp, Nicholas; Smith, Austin

2015-10-19

Human pluripotent stem cells can in principle be used as a source of any differentiated cell type for disease modelling, drug screening, toxicology testing or cell replacement therapy. Type I diabetes is considered a major target for stem cell applications due to the shortage of primary human beta cells. Several protocols have been reported for generating pancreatic progenitors by in vitro differentiation of human pluripotent stem cells. Here we first assessed one of these protocols on a panel of pluripotent stem cell lines for capacity to engender glucose sensitive insulin-producing cells after engraftment in immunocompromised mice. We observed variable outcomes with only one cell line showing a low level of glucose response. We, therefore, undertook a systematic comparison of different methods for inducing definitive endoderm and subsequently pancreatic differentiation. Of several protocols tested, we identified a combined approach that robustly generated pancreatic progenitors in vitro from both embryo-derived and induced pluripotent stem cells. These findings suggest that, although there are intrinsic differences in lineage specification propensity between pluripotent stem cell lines, optimal differentiation procedures may consistently direct a substantial fraction of cells into pancreatic specification. © 2015 The Authors.

CT findings in autoimmune pancreatitis: assessment using multiphase contrast-enhanced multisection CT

Energy Technology Data Exchange (ETDEWEB)

Suzuki, K., E-mail: Kojiro@med.nagoya-u.ac.j [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan); Itoh, S. [Department of Radiology, Nagoya Hirokoji Clinic, Nagoya (Japan); Nagasaka, T. [Departments of Medical Technology, Nagoya University School of Health Science, Nagoya (Japan); Ogawa, H.; Ota, T.; Naganawa, S. [Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya (Japan)

2010-09-15

Aim: To assess the spectrum of findings using multiphase contrast-enhanced computed tomography (CT) in patients with autoimmune pancreatitis (AIP). Materials and methods: Fifty patients (four female and 46 male, mean age 65 years) were retrospectively identified from consecutive patients with abnormal CT findings of the pancreas and negative work-up for known causes. These patients had at least one finding supporting the diagnosis of AIP: serological abnormality, histopathological abnormality, or response to steroid. Two radiologists evaluated multiphase contrast-enhanced CT images in consensus. Results: The pancreas showed diffuse enlargement (n = 16; 32%), focal enlargement (n = 18; 36%), or no enlargement (n = 16; 32%). Forty-nine (98%) patients showed abnormal contrast enhancement in the affected pancreatic parenchyma, including hypoattenuation during the pancreatic phase (n = 45; 90%) and hyperattenuation during the delayed phase (n = 39; 87%). The following findings were also seen in the pancreas: a capsule-like rim (n = 24; 48%); no visualization of the main pancreatic duct lumen (n = 48; 96%); ductal enhancement (n = 26; 52%); upstream dilatation of the main pancreatic duct (n = 27; 54%); upstream atrophy of the pancreatic parenchyma (n = 27; 54%); calcification (n = 7; 14%); and cysts (n = 5; 10%). Forty-two (84%) patients showed one or more of the following extrapancreatic findings: biliary duct or gallbladder abnormality (n = 40; 80%); peripancreatic (n = 8; 16%) or para-aortic (n = 10; 20%) soft-tissue proliferation; and renal involvement (n = 15; 30%). Conclusion: Patients with AIP presented with a variety of CT findings in the pancreas and the extrapancreatic organs. The present study highlights pancreatic ductal enhancement in a subset of patients with AIP.

Alkali pH directly activates ATP-sensitive K+ channels and inhibits insulin secretion in beta-cells.

Science.gov (United States)

Manning Fox, Jocelyn E; Karaman, Gunce; Wheeler, Michael B

2006-11-17

Glucose stimulation of pancreatic beta-cells is reported to lead to sustained alkalization, while extracellular application of weak bases is reported to inhibit electrical activity and decrease insulin secretion. We hypothesize that beta-cell K(ATP) channel activity is modulated by alkaline pH. Using the excised patch-clamp technique, we demonstrate a direct stimulatory action of alkali pH on recombinant SUR1/Kir6.2 channels due to increased open probability. Bath application of alkali pH similarly activates native islet beta-cell K(ATP) channels, leading to an inhibition of action potentials, and hyperpolarization of membrane potential. In situ pancreatic perfusion confirms that these cellular effects of alkali pH are observable at a functional level, resulting in decreases in both phase 1 and phase 2 glucose-stimulated insulin secretion. Our data are the first to report a stimulatory effect of a range of alkali pH on K(ATP) channel activity and link this to downstream effects on islet beta-cell function.

Combined treatment with lisofylline and exendin-4 reverses autoimmune diabetes

International Nuclear Information System (INIS)

Yang Zandong; Chen Meng; Carter, Jeffrey D.; Nunemaker, Craig S.; Garmey, James C.; Kimble, Sarah D.; Nadler, Jerry L.

2006-01-01

Type 1 diabetes mellitus (T1DM) is an autoimmune disease leading to near complete pancreatic β-cell destruction. New evidence suggests that β-cell regeneration is possible, but ongoing autoimmune damage prevents restoration of β-cell mass. We tested the hypothesis that simultaneously blocking autoimmune cytokine damage and supplying a growth-promoting stimulus for β-cells would provide a novel approach to reverse T1DM. Therefore, in this study we combined lisofylline to suppress autoimmunity and exendin-4 to enhance β-cell proliferation for treating autoimmune-mediated diabetes in the non-obese diabetic (NOD) mouse model. We found that this combined therapy effectively reversed new-onset diabetes within a week of therapy, and even maintained euglycemia up to 145 days after treatment withdrawal. The therapeutic effect of this regimen was associated with improved β-cell metabolism and insulin secretion, while reducing β-cell apoptosis. It is possible that such combined therapy could become a new strategy to defeat T1DM in humans

Suppressor of cytokine signalling (SOCS)-3 protects beta cells against IL-1beta-mediated toxicity through inhibition of multiple nuclear factor-kappaB-regulated proapoptotic pathways

DEFF Research Database (Denmark)

Karlsen, Allan Ertman; Heding, P E; Frobøse, H

2004-01-01

The proinflammatory cytokine IL-1beta induces apoptosis in pancreatic beta cells via pathways dependent on nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinase, and protein kinase C. We recently showed suppressor of cytokine signalling (SOCS)-3 to be a natural negative feedback reg...... regulator of IL-1beta- and IFN-gamma-mediated signalling in rat islets and beta cell lines, preventing their deleterious effects. However, the mechanisms underlying SOCS-3 inhibition of IL-1beta signalling and prevention against apoptosis remain unknown....

A Case of Autoimmune Pancreatitis Presenting as a Deterioration in Glycaemic Control in a Patient with Pre-Existing Type 2 Diabetes

LENUS (Irish Health Repository)

Forde, H

2017-05-01

Autoimmune pancreatitis (AIP) was first described in 1961 and accounts for 5-6% of cases of chronic pancreatitis, though the prevalence is increasing with increasing awareness of the disease1,2. There are two types of autoimmune pancreatitis with different clinical and pathological features. Type 1 AIP is an IgG4 related disease and tends to occur in elderly patients in the 7th decade, with a male preponderance3. Type 1 AIP is associated with other organ involvement and commonly affects the biliary system3. In contrast, Type 2 AIP occurs in patients in the 5th-6th decade of life and other organ involvement is uncommon3. Both types of AIP respond well to steroids with reported remission rates of 99% and 92% for Type 1 and Type 2 AIP respectively4.\\r\

Reprogramming of various cell types to a beta-like state by Pdx1, Ngn3 and MafA.

Directory of Open Access Journals (Sweden)

Ersin Akinci

Full Text Available The three transcription factors, PDX1, NGN3 and MAFA, are very important in pancreatic development. Overexpression of these three factors can reprogram both pancreatic exocrine cells and SOX9-positive cells of the liver into cells resembling pancreatic beta cells. In this study we investigate whether other cell types can be reprogrammed. Eight cell types are compared and the results are consistent with the idea that reprogramming occurs to a greater degree for developmentally related cells (pancreas, liver than for other types, such as fibroblasts. Using a line of mouse hepatocyte-derived cells we screened 13 compounds for the ability to increase the yield of reprogrammed cells. Three are active and when used in combination they can increase the yield of insulin-immunopositive cells by a factor of six. These results should contribute to the eventual ability to develop a new cure for diabetes based on the ability to reprogram other cells in the body to a beta cell phenotype.

PDX1, Neurogenin-3, and MAFA: critical transcription regulators for beta cell development and regeneration

Directory of Open Access Journals (Sweden)

Yaxi Zhu

2017-11-01

Full Text Available Abstract Transcription factors regulate gene expression through binding to specific enhancer sequences. Pancreas/duodenum homeobox protein 1 (PDX1, Neurogenin-3 (NEUROG3, and V-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MAFA are transcription factors critical for beta cell development and maturation. NEUROG3 is expressed in endocrine progenitor cells and controls islet differentiation and regeneration. PDX1 is essential for the development of pancreatic exocrine and endocrine cells including beta cells. PDX1 also binds to the regulatory elements and increases insulin gene transcription. Likewise, MAFA binds to the enhancer/promoter region of the insulin gene and drives insulin expression in response to glucose. In addition to those natural roles in beta cell development and maturation, ectopic expression of PDX1, NEUROG3, and/or MAFA has been successfully used to reprogram various cell types into insulin-producing cells in vitro and in vivo, such as pancreatic exocrine cells, hepatocytes, and pluripotent stem cells. Here, we review biological properties of PDX1, NEUROG3, and MAFA, and their applications and limitations for beta cell regenerative approaches. The primary source literature for this review was acquired using a PubMed search for articles published between 1990 and 2017. Search terms include diabetes, insulin, trans-differentiation, stem cells, and regenerative medicine.

Can pancreatic duct-derived progenitors be a source of islet regeneration?

Energy Technology Data Exchange (ETDEWEB)

Xia, Bing [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Zhan, Xiao-Rong, E-mail: xiaorongzhan@sina.com [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yi, Ran [Department of Endocrinology, First Hospital of Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China); Yang, Baofeng [Department of Pharmacology, State Key Laboratory of Biomedicine and Pharmacology, Harbin Medical University, Harbin, Hei Long Jiang Province 150001 (China)

2009-06-12

The regenerative process of the pancreas is of interest because the main pathogenesis of diabetes mellitus is an inadequate number of insulin-producing {beta}-cells. The functional mass of {beta}-cells is decreased in type 1 diabetes, so replacing missing {beta}-cells or triggering their regeneration may allow for improved type 1 diabetes treatment. Therefore, expansion of the {beta}-cell mass from endogenous sources, either in vivo or in vitro, represents an area of increasing interest. The mechanism of islet regeneration remains poorly understood, but the identification of islet progenitor sources is critical for understanding {beta}-cell regeneration. One potential source is the islet proper, via the dedifferentiation, proliferation, and redifferentiation of facultative progenitors residing within the islet. Neogenesis, or that the new pancreatic islets can derive from progenitor cells present within the ducts has been reported, but the existence and identity of the progenitor cells have been debated. In this review, we focus on pancreatic ductal cells, which are islet progenitors capable of differentiating into islet {beta}-cells. Islet neogenesis, seen as budding of hormone-positive cells from the ductal epithelium, is considered to be one mechanism for normal islet growth after birth and in regeneration, and has suggested the presence of pancreatic stem cells. Numerous results support the neogenesis hypothesis, the evidence for the hypothesis in the adult comes primarily from morphological studies that have in common the production of damage to all or part of the pancreas, with consequent inflammation and repair. Although numerous studies support a ductal origin for new islets after birth, lineage-tracing experiments are considered the 'gold standard' of proof. Lineage-tracing experiments show that pancreatic duct cells act as progenitors, giving rise to new islets after birth and after injury. The identification of differentiated pancreatic ductal

Foodborne cereulide causes beta-cell dysfunction and apoptosis.

Directory of Open Access Journals (Sweden)

Roman Vangoitsenhoven

Full Text Available To study the effects of cereulide, a food toxin often found at low concentrations in take-away meals, on beta-cell survival and function.Cell death was quantified by Hoechst/Propidium Iodide in mouse (MIN6 and rat (INS-1E beta-cell lines, whole mouse islets and control cell lines (HepG2 and COS-1. Beta-cell function was studied by glucose-stimulated insulin secretion (GSIS. Mechanisms of toxicity were evaluated in MIN6 cells by mRNA profiling, electron microscopy and mitochondrial function tests.24 h exposure to 5 ng/ml cereulide rendered almost all MIN6, INS-1E and pancreatic islets apoptotic, whereas cell death did not increase in the control cell lines. In MIN6 cells and murine islets, GSIS capacity was lost following 24 h exposure to 0.5 ng/ml cereulide (P<0.05. Cereulide exposure induced markers of mitochondrial stress including Puma (p53 up-regulated modulator of apoptosis, P<0.05 and general pro-apoptotic signals as Chop (CCAAT/-enhancer-binding protein homologous protein. Mitochondria appeared swollen upon transmission electron microscopy, basal respiration rate was reduced by 52% (P<0.05 and reactive oxygen species increased by more than twofold (P<0.05 following 24 h exposure to 0.25 and 0.50 ng/ml cereulide, respectively.Cereulide causes apoptotic beta-cell death at low concentrations and impairs beta-cell function at even lower concentrations, with mitochondrial dysfunction underlying these defects. Thus, exposure to cereulide even at concentrations too low to cause systemic effects appears deleterious to the beta-cell.

[Diagnostic utility of endoscopic ultrasonography elastography and contrast-enhanced harmonic endoscopic ultrasonography in a patient with type 2 autoimmune pancreatitis].

Science.gov (United States)

Yokode, Masataka; Shiomi, Hideyuki; Itai, Ryosuke; Mikami, Sakae; Yamashita, Yukimasa; Nakano, Ryota; Ezaki, Takeshi; Masuda, Atsuhiro; Zen, Yoh

2018-01-01

A referring hospital diagnosed a 57-year-old man with a pancreatic head mass. The initial endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) was inconclusive because of the small sample size. Endoscopic ultrasonography elastography (EUS-EG) and contrast-enhanced harmonic endoscopic ultrasonography (CE-EUS), conducted at our institute, raised the possibility of mass-forming pancreatitis or autoimmune pancreatitis (AIP). A repeat EUS-FNA revealed inflammatory changes, including a neutrophilic duct injury suggestive of type 2 AIP. The pancreatic lesion responded well to the steroid therapy. The present case suggests that EUS-EG and CE-EUS may be useful for diagnostic exclusion of pancreatic cancers, and the combined use of EUS-EG and CE-EUS, with EUS-FNA, may help characterize inflammatory pancreatic lesions.

Modulation of Autoimmune T-Cell Memory by Stem Cell Educator Therapy: Phase 1/2 Clinical Trial.

Science.gov (United States)

Delgado, Elias; Perez-Basterrechea, Marcos; Suarez-Alvarez, Beatriz; Zhou, Huimin; Revuelta, Eva Martinez; Garcia-Gala, Jose Maria; Perez, Silvia; Alvarez-Viejo, Maria; Menendez, Edelmiro; Lopez-Larrea, Carlos; Tang, Ruifeng; Zhu, Zhenlong; Hu, Wei; Moss, Thomas; Guindi, Edward; Otero, Jesus; Zhao, Yong

2015-12-01

Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease that causes a deficit of pancreatic islet β cells. The complexities of overcoming autoimmunity in T1D have contributed to the challenges the research community faces when devising successful treatments with conventional immune therapies. Overcoming autoimmune T cell memory represents one of the key hurdles. In this open-label, phase 1/phase 2 study, Caucasian T1D patients (N = 15) received two treatments with the Stem Cell Educator (SCE) therapy, an approach that uses human multipotent cord blood-derived multipotent stem cells (CB-SCs). SCE therapy involves a closed-loop system that briefly treats the patient's lymphocytes with CB-SCs in vitro and returns the "educated" lymphocytes (but not the CB-SCs) into the patient's blood circulation. This study is registered with ClinicalTrials.gov, NCT01350219. Clinical data demonstrated that SCE therapy was well tolerated in all subjects. The percentage of naïve CD4(+) T cells was significantly increased at 26 weeks and maintained through the final follow-up at 56 weeks. The percentage of CD4(+) central memory T cells (TCM) was markedly and constantly increased at 18 weeks. Both CD4(+) effector memory T cells (TEM) and CD8(+) TEM cells were considerably decreased at 18 weeks and 26 weeks respectively. Additional clinical data demonstrated the modulation of C-C chemokine receptor 7 (CCR7) expressions on naïve T, TCM, and TEM cells. Following two treatments with SCE therapy, islet β-cell function was improved and maintained in individuals with residual β-cell function, but not in those without residual β-cell function. Current clinical data demonstrated the safety and efficacy of SCE therapy in immune modulation. SCE therapy provides lasting reversal of autoimmune memory that could improve islet β-cell function in Caucasian subjects. Obra Social "La Caixa", Instituto de Salud Carlos III, Red de Investigación Renal, European Union FEDER Funds, Principado de

GTP- and GDP-Dependent Rab27a Effectors in Pancreatic Beta-Cells.

Science.gov (United States)

Yamaoka, Mami; Ishizaki, Toshimasa; Kimura, Toshihide

2015-01-01

Small guanosine triphosphatases (GTPases) participate in a wide variety of cellular functions including proliferation, differentiation, adhesion, and intracellular transport. Conventionally, only the guanosine 5'-triphosphate (GTP)-bound small GTPase interacts with effector proteins, and the resulting downstream signals control specific cellular functions. Therefore, the GTP-bound form is regarded as active, and the focus has been on searching for proteins that bind the GTP form to look for their effectors. The Rab family small GTPase Rab27a is highly expressed in some secretory cells and is involved in the control of membrane traffic. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in pancreatic beta-cells. In the basal state, GTP-bound Rab27a controls insulin secretion at pre-exocytic stages via its GTP-dependent effectors. We previously identified novel guanosine 5'-diphosphate (GDP)-bound Rab27-interacting proteins. Interestingly, GDP-bound Rab27a controls endocytosis of the secretory membrane via its interaction with these proteins. We also demonstrated that the insulin secretagogue glucose converts Rab27a from its GTP- to GDP-bound forms. Thus, GTP- and GDP-bound Rab27a regulate pre-exocytic and endocytic stages in membrane traffic, respectively. Since the physiological importance of GDP-bound GTPases has been largely overlooked, we consider that the investigation of GDP-dependent effectors for other GTPases is necessary for further understanding of cellular function.

Paracrine GABA and insulin regulate pancreatic alpha cell proliferation in a mouse model of type 1 diabetes.

Science.gov (United States)

Feng, Allen L; Xiang, Yun-Yan; Gui, Le; Kaltsidis, Gesthika; Feng, Qingping; Lu, Wei-Yang

2017-06-01

This study aimed to elucidate the mechanism of increased proliferation of alpha cells in recent-onset type 1 diabetes. Pancreatic beta cells express GAD and produce γ-aminobutyric acid (GABA), which inhibits alpha cell secretion of glucagon. We explored the roles of GABA in alpha cell proliferation in conditions corresponding to type 1 diabetes in a mouse model and in vitro. Type 1 diabetes was induced by injecting the mice with streptozotocin (STZ). Some of the STZ-injected mice were treated with GABA (10 mg/kg daily) for 12 days. Isolated pancreatic islets were treated with STZ or STZ together with GABA for 2 days. The effects of GABA treatment on STZ-induced alpha cell proliferation in vivo and in vitro were assessed. The effect of muscimol, a GABA receptor agonist, on αTC1-6 cell proliferation was also examined. STZ injection substantially decreased levels of GAD, GABA and insulin in pancreatic beta cells 12 h after injection; this was followed by an upsurge of phosphorylated mechanistic target of rapamycin (p-mTOR) in the alpha cells at day 1, and a significant increase in alpha cell mass at day 3. Treating STZ-injected mice with GABA largely restored the immunodetectable levels of insulin and GAD in the beta cells and significantly decreased the number of aldehyde dehydrogenase 1 family, member A3 (ALDH1a3)-positive cells, alpha cell mass and hyperglucagonaemia. STZ treatment also increased alpha cell proliferation in isolated islets, which was reversed by co-treatment with GABA. Muscimol, together with insulin, significantly lowered the level of cytosolic Ca 2+ and p-mTOR, and decreased the proliferation rate of αTC1-6 cells. GABA signalling critically controls the alpha cell population in pancreatic islets. Low intraislet GABA may contribute to alpha cell hyperplasia in early type 1 diabetes.

Antibody Response to Serpin B13 Induces Adaptive Changes in Mouse Pancreatic Islets and Slows Down the Decline in the Residual Beta Cell Function in Children with Recent Onset of Type 1 Diabetes Mellitus.

Science.gov (United States)

Kryvalap, Yury; Lo, Chi-Wen; Manuylova, Ekaterina; Baldzizhar, Raman; Jospe, Nicholas; Czyzyk, Jan

2016-01-01

Type 1 diabetes mellitus (T1D) is characterized by a heightened antibody (Ab) response to pancreatic islet self-antigens, which is a biomarker of progressive islet pathology. We recently identified a novel antibody to clade B serpin that reduces islet-associated T cell accumulation and is linked to the delayed onset of T1D. As natural immunity to clade B arises early in life, we hypothesized that it may influence islet development during that time. To test this possibility healthy young Balb/c male mice were injected with serpin B13 mAb or IgG control and examined for the number and cellularity of pancreatic islets by immunofluorescence and FACS. Beta cell proliferation was assessed by measuring nucleotide analog 5-ethynyl-2'-deoxyuridine (5-EdU) incorporation into the DNA and islet Reg gene expression was measured by real time PCR. Human studies involved measuring anti-serpin B13 autoantibodies by Luminex. We found that injecting anti-serpin B13 monoclonal Ab enhanced beta cell proliferation and Reg gene expression, induced the generation of ∼80 pancreatic islets per animal, and ultimately led to increase in the beta cell mass. These findings are relevant to human T1D because our analysis of subjects just diagnosed with T1D revealed an association between baseline anti-serpin activity and slower residual beta cell function decline in the first year after the onset of diabetes. Our findings reveal a new role for the anti-serpin immunological response in promoting adaptive changes in the endocrine pancreas and suggests that enhancement of this response could potentially help impede the progression of T1D in humans. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Regulatory T-cells and autoimmunity.

LENUS (Irish Health Repository)

Ni Choileain, Niamh

2012-02-03

Approximately 20% of the population is affected by autoimmune or inflammatory diseases mediated by an abnormal immune response. A characteristic feature of autoimmune disease is the selective targeting of a single cell type, organ or tissue by certain populations of autoreactive T-cells. Examples of such diseases include rheumatoid arthritis, insulin-dependent diabetes mellitus, and systemic lupus erythematosus (SLE), all of which are characterized by chronic inflammation, tissue destruction and target organ malfunction. Although strong evidence links most autoimmune diseases to specific genes, considerable controversy prevails regarding the role of regulatory T-cell populations in the disease process. These cells are now also believed to play a key role in mediating transplantation tolerance and inhibiting the induction of tumor immunity. Though the concept of therapeutic immune regulation aimed at treating autoimmune pathology has been validated in many animal models, the development of strategies for the treatment of human autoimmune disorders remains in its infancy. The main obstacles to this include the conflicting findings of different model systems, as well as the contrasting functions of regulatory T-cells and cytokines involved in the development of such disorders. This review examines the role of regulatory T-cells in the pathogenesis of autoimmunity and describes the therapeutic potential of these cells for the prevention of immune-mediated pathologies in the future. Although much remains to be learned about such pathologies, a clearer understanding of the mechanisms by which regulatory T-cells function will undoubtedly lead to exciting new possibilities for immunotherapeutics.

Co-culture of neural crest stem cells (NCSC and insulin producing beta-TC6 cells results in cadherin junctions and protection against cytokine-induced beta-cell death.

Directory of Open Access Journals (Sweden)

Anongnad Ngamjariyawat

Full Text Available PURPOSE: Transplantation of pancreatic islets to Type 1 diabetes patients is hampered by inflammatory reactions at the transplantation site leading to dysfunction and death of insulin producing beta-cells. Recently we have shown that co-transplantation of neural crest stem cells (NCSCs together with the islet cells improves transplantation outcome. The aim of the present investigation was to describe in vitro interactions between NCSCs and insulin producing beta-TC6 cells that may mediate protection against cytokine-induced beta-cell death. PROCEDURES: Beta-TC6 and NCSC cells were cultured either alone or together, and either with or without cell culture inserts. The cultures were then exposed to the pro-inflammatory cytokines IL-1β and IFN-γ for 48 hours followed by analysis of cell death rates (flow cytometry, nitrite production (Griess reagent, protein localization (immunofluorescence and protein phosphorylation (flow cytometry. RESULTS: We observed that beta-TC6 cells co-cultured with NCSCs were protected against cytokine-induced cell death, but not when separated by cell culture inserts. This occurred in parallel with (i augmented production of nitrite from beta-TC6 cells, indicating that increased cell survival allows a sustained production of nitric oxide; (ii NCSC-derived laminin production; (iii decreased phospho-FAK staining in beta-TC6 cell focal adhesions, and (iv decreased beta-TC6 cell phosphorylation of ERK(T202/Y204, FAK(Y397 and FAK(Y576. Furthermore, co-culture also resulted in cadherin and beta-catenin accumulations at the NCSC/beta-TC6 cell junctions. Finally, the gap junction inhibitor carbenoxolone did not affect cytokine-induced beta-cell death during co-culture with NCSCs. CONCLUSION: In summary, direct contacts, but not soluble factors, promote improved beta-TC6 viability when co-cultured with NCSCs. We hypothesize that cadherin junctions between NCSC and beta-TC6 cells promote powerful signals that maintain beta-cell

IgG4-related retroperitoneal fibrosis and sclerosing cholangitis independent of autoimmune pancreatitis. A recurrent case after a 5-year history of spontaneous remission.

Science.gov (United States)

Miura, Hideaki; Miyachi, Yasutaka

2009-07-06

A new clinicopathological concept of IgG4-related sclerosing disease affecting various organs has recently been proposed in relation to autoimmune pancreatitis. This report describes the case of IgG4-related retroperitoneal fibrosis and sclerosing cholangitis independent of autoimmune pancreatitis, which recurred after a long period of spontaneous remission. An 80-year-old Japanese man presented with obstructive jaundice owing to a hepatic hilum bile duct stricture. Coincidentally, a soft tissue mass surrounding the abdominal aorta, suggesting retroperitoneal fibrosis, was identified. Unexpectedly, spontaneous regression of obstructive jaundice together with retroperitoneal fibrosis occurred. The presence of high serum IgG4 concentrations measured later led us to consider a possible association with autoimmune pancreatitis; however, there were no clinical features confirming autoimmune pancreatitis. After a 5-year history of spontaneous clinical remission, there was an elevation of serum IgG4 levels and renal dysfunction owing to bilateral hydronephrosis caused by a reemergence of the retroperitoneal mass. Evaluation by endoscopic retrograde cholangiopancreatography revealed a biliary stricture, suggesting sclerosing cholangitis which was observed without the presence of any pancreatic duct abnormality. The subsequent excellent results obtained using steroid therapy, namely the decrease in serum IgG4 levels and the regression of the retroperitoneal mass, strongly suggested that the present case was an IgG4-related sclerosing disease. Aside from high serum IgG4 concentrations, markedly elevated levels of serum IgE was found retrospectively, although the clinical significance remains unknown. When we encounter fibrotic diseases of unknown etiology, we should measure serum IgG4 concentrations and monitor the disease activity over long periods even after achieving clinical remission.

Diabetes mellitus in Tropical Chronic Pancreatitis Is Not Just a Secondary Type of Diabetes

OpenAIRE

Rossi, L.; Parvin, S.; Hassan, Z.; Hildebrand, P.; Keller, U.; Ali, L.; Beglinger, C.; Azad Khan, A. K.; Whitcomb, David C.; Gyr, N.

2004-01-01

AIMS: In chronic calcific pancreatitis of the tropics, etiology and relationship to developing diabetes mellitus are unknown. Some consider these cases a straightforward secondary type of diabetes, while others suggest selective beta-cell impairment. Testing pancreatic function, we investigated whether selective beta-cell impairment triggers diabetes associated with tropical pancreatitis. METHODS: At a Bangladeshi research institute, 8 chronic tropical pancreatitis and no diabetes mellitus su...

The enteroinsular axis and endocrine pancreatic function in chronic alcohol consumers: evidence for early beta-cell hypofunction.

Science.gov (United States)

Patto, R J; Russo, E K; Borges, D R; Neves, M M

1993-09-01

Chronic alcohol consumers may have, as judged by functional criteria, exocrine as well as endocrine pancreatic dysfunction, the latter represented by a decreased insulin response to an oral glucose load. To investigate whether this decreased insulin response was due to an ethanol-induced beta-cell dysfunction or to an ethanol-induced dysfunction of the enteroinsular axis, we determined glucose, insulin, and C-peptide plasma concentrations following an oral and an intravenous glucose load in 16 healthy volunteer nonalcohol consumers and in 10 chronic alcohol consumers. In each group, total integrated response for glucose did not significantly change whether glucose was given orally or intravenously, indicating isoglycemic glucose loads. The total integrated response values for insulin in the alcoholic group following both glucose loads as well as C-peptide plasma concentrations were significantly lower than in the control group. Moreover, in both groups the insulin TIR values following the oral glucose load were significantly greater than the values obtained following the intravenous glucose load, indicating an incretin effect. These results indicate that the decreased insulin response observed in alcoholics was not caused by a dysfunction of the enteroinsular axis because it also occurred following an intravenous glucose load, but by an ethanol-induced beta-cell dysfunction because C-peptide and insulin were proportionally decreased in this group.

Tight Junctions, Intestinal Permeability, and Autoimmunity Celiac Disease and Type 1 Diabetes Paradigms

Science.gov (United States)

Visser, Jeroen; Rozing, Jan; Sapone, Anna; Lammers, Karen; Fasano, Alessio

2010-01-01

Autoimmune diseases are characterized by tissue damage and loss of function due to an immune response that is directed against specific organs. This review is focused on celiac disease (CD), an autoimmune enteropathy, and type 1 diabetes (T1D), a hyperglycosaemia caused by a destructive autoimmune process targeting the insulin-producing pancreatic islet cells. Even if environmental factors and genetic susceptibility are clearly involved in the pathogenesis of autoimmunity, for most autoimmune disorders there is no or little knowledge about the causing agent or genetic makeup underlying the disease. In this respect, CD represents a unique autoimmune disorder because a close genetic association with HLA-DQ2 or HLA-DQ8 haplotypes and, more importantly, the environmental trigger (the gliadin fraction of gluten-containing grains wheat, barley, and rye) are known. Conversely, the trigger for autoimmune destruction of pancreatic ß cells in T1D is unclear. Interestingly, recent data suggest that gliadin is also involved in the pathogenesis of T1D. There is growing evidence that increased intestinal permeability plays a pathogenic role in various autoimmune diseases including CD and T1D. Therefore, we hypothesize that besides genetic and environmental factors, loss of intestinal barrier function is necessary to develop autoimmunity. In this review, each of these components will be briefly reviewed. PMID:19538307

NK cell autoreactivity and autoimmune diseases

Directory of Open Access Journals (Sweden)

Alessandro ePoggi

2014-02-01

Full Text Available Increasing evidences have pointed out the relevance of Natural Killer (NK cells in organ specific and systemic autoimmune diseases. NK cells bear a plethora of activating and inhibiting receptors that can play a role in regulating reactivity with autologous cells. The activating receptors recognize natural ligands upregulated on virus-infected or stressed or neoplastic cells. Of note, several autoimmune diseases are thought to be linked to viral infections as one of the first event in inducing autoimmunity. Also, it is conceivable that autoimmunity can be triggered when a dysregulation of innate immunity occurs, activating T and B lymphocytes to react with self-components. This would imply that NK cells can play a regulatory role during adaptive immunity; indeed, innate lymphoid cells (ILC, comprising the classical CD56+ NK cells, have a role in maintaining or alterating tissue homeostasis secreting protective and/or proinflammatory cytokines. In addition, NK cells display activating receptors involved in natural cytotoxicity and the activating isoforms of receptors for HLA class I that can interact with healthy host cells and induce damage without any evidence of viral infection or neoplastic-induced alteration. In this context, the interrelationship among ILC, extracellular matrix components and mesenchymal stromal cells can be considered a key point for the control of homeostasis. Herein, we summarize evidences for a role of NK cells in autoimmune diseases and will give a point of view of the interplay between NK cells and self-cells in triggering autoimmunity.

Role of MicroRNAs in Islet Beta-Cell Compensation and Failure during Diabetes

Directory of Open Access Journals (Sweden)

Valérie Plaisance

2014-01-01

Full Text Available Pancreatic beta-cell function and mass are markedly adaptive to compensate for the changes in insulin requirement observed during several situations such as pregnancy, obesity, glucocorticoids excess, or administration. This requires a beta-cell compensation which is achieved through a gain of beta-cell mass and function. Elucidating the physiological mechanisms that promote functional beta-cell mass expansion and that protect cells against death, is a key therapeutic target for diabetes. In this respect, several recent studies have emphasized the instrumental role of microRNAs in the control of beta-cell function. MicroRNAs are negative regulators of gene expression, and are pivotal for the control of beta-cell proliferation, function, and survival. On the one hand, changes in specific microRNA levels have been associated with beta-cell compensation and are triggered by hormones or bioactive peptides that promote beta-cell survival and function. Conversely, modifications in the expression of other specific microRNAs contribute to beta-cell dysfunction and death elicited by diabetogenic factors including, cytokines, chronic hyperlipidemia, hyperglycemia, and oxidized LDL. This review underlines the importance of targeting the microRNA network for future innovative therapies aiming at preventing the beta-cell decline in diabetes.

Pancreatitis autoinmune: pseudotumor inflamatorio, afectación multifocal, hipertensión portal y evolución a largo plazo Autoimmune pancreatitis: inflammatory pseudotumor, multifocal fibrosclerosis, portal hypertension, and long-term outcome

Directory of Open Access Journals (Sweden)

J. L. Beristain

2008-10-01

Full Text Available La pancreatitis autoinmune es una enfermedad recientemente caracterizada y que en la actualidad constituye un reto diagnóstico especialmente su diferenciación con el cáncer de páncreas. Su evolución a largo plazo es poco conocida, presentándose un caso estudiado a lo largo de 14 años y mostrando su evolución clínica, bioquímica y morfológica. Paciente mujer de 54 años que debuta con un cuadro de ictericia obstructiva y molestias abdominales inespecíficas y constatación en la TAC de un aumento de la cabeza del páncreas, todo ello sugestivo de neoplasia de páncreas. Fue intervenida evidenciándose un aumento difuso de todo el páncreas descartándose malignidad intraoperatoriamente, realizando únicamente colecistectomía y coledocoduodenostomía, quedando diagnosticada entonces como pancreatitis crónica. Durante los años posteriores fueron apareciendo diferentes procesos autoinmunes como asma, sialoadenitis y colangitis esclerosante secundaria, así como episodios recurrentes de ictericia e insuficiencia pancreática endocrina y exocrina. La aparición de estas complicaciones y la detección de niveles séricos elevados de IgG4 y de anticuerpos antianhidrasa carbónica II condujo a la reevaluación de la histología inicial concluyendo finalmente con el diagnóstico de pancreatitis autoinmune al evidenciarse una infiltración linfocitaria y plasmacitaria IgG4+, así como fibrosis y flebitis obliterativa. En los últimos años se ha añadido a las anteriores complicaciones una fibrosis retroperitoneal con hipertensión portal, varices esofágicas y esplenomegalia.Autoimmune pancreatitis is a recently characterized disease that still constitutes a diagnostic challenge, especially regarding differential diagnosis from neoplasia. Long-term outcome is poorly known. We herein report a case of a patient with autoimmune pancreatitis and 14 years of follow-up, and show its clinical, biochemical, and morphological characteristics. A 54

Exosomes Derived From Pancreatic Stellate Cells: MicroRNA Signature and Effects on Pancreatic Cancer Cells.

Science.gov (United States)

Takikawa, Tetsuya; Masamune, Atsushi; Yoshida, Naoki; Hamada, Shin; Kogure, Takayuki; Shimosegawa, Tooru

2017-01-01

Pancreatic stellate cells (PSCs) interact with pancreatic cancer cells in the tumor microenvironment. Cell constituents including microRNAs may be exported from cells within membranous nanovesicles termed exosomes. Exosomes might play a pivotal role in intercellular communication. This study aimed to clarify the microRNA signature of PSC-derived exosomes and their effects on pancreatic cancer cells. Exosomes were prepared from the conditioned medium of immortalized human PSCs. MicroRNAs were prepared from the exosomes and their source PSCs, and the microRNA expression profiles were compared by microarray. The effects of PSC-derived exosomes on proliferation, migration, and the mRNA expression profiles were examined in pancreatic cancer cells. Pancreatic stellate cell-derived exosomes contained a variety of microRNAs including miR-21-5p. Several microRNAs such as miR-451a were enriched in exosomes compared to their source PSCs. Pancreatic stellate cell-derived exosomes stimulated the proliferation, migration and expression of mRNAs for chemokine (C - X - C motif) ligands 1 and 2 in pancreatic cancer cells. The stimulation of proliferation, migration, and chemokine gene expression by the conditioned medium of PSCs was suppressed by GW4869, an exosome inhibitor. We clarified the microRNA expression profile in PSC-derived exosomes. Pancreatic stellate cell-derived exosomes might play a role in the interactions between PSCs and pancreatic cancer cells.

In vitro modeling of human pancreatic duct epithelial cell transformation defines gene expression changes induced by K-ras oncogenic activation in pancreatic carcinogenesis.

Science.gov (United States)

Qian, Jiaying; Niu, Jiangong; Li, Ming; Chiao, Paul J; Tsao, Ming-Sound

2005-06-15

Genetic analysis of pancreatic ductal adenocarcinomas and their putative precursor lesions, pancreatic intraepithelial neoplasias (PanIN), has shown a multistep molecular paradigm for duct cell carcinogenesis. Mutational activation or inactivation of the K-ras, p16(INK4A), Smad4, and p53 genes occur at progressive and high frequencies in these lesions. Oncogenic activation of the K-ras gene occurs in >90% of pancreatic ductal carcinoma and is found early in the PanIN-carcinoma sequence, but its functional roles remain poorly understood. We show here that the expression of K-ras(G12V) oncogene in a near diploid HPV16-E6E7 gene immortalized human pancreatic duct epithelial cell line originally derived from normal pancreas induced the formation of carcinoma in 50% of severe combined immunodeficient mice implanted with these cells. A tumor cell line established from one of these tumors formed ductal cancer when implanted orthotopically. These cells also showed increased activation of the mitogen-activated protein kinase, AKT, and nuclear factor-kappaB pathways. Microarray expression profiling studies identified 584 genes whose expression seemed specifically up-regulated by the K-ras oncogene expression. Forty-two of these genes have been reported previously as differentially overexpressed in pancreatic cancer cell lines or primary tumors. Real-time PCR confirmed the overexpression of a large number of these genes. Immunohistochemistry done on tissue microarrays constructed from PanIN and pancreatic cancer samples showed laminin beta3 overexpression starting in high-grade PanINs and occurring in >90% of pancreatic ductal carcinoma. The in vitro modeling of human pancreatic duct epithelial cell transformation may provide mechanistic insights on gene expression changes that occur during multistage pancreatic duct cell carcinogenesis.

Genetically Engineered Islets and Alternative Sources of Insulin-Producing Cells for Treating Autoimmune Diabetes: Quo Vadis?

Directory of Open Access Journals (Sweden)

Feng-Cheng Chou

2012-01-01

Full Text Available Islet transplantation is a promising therapy for patients with type 1 diabetes that can provide moment-to-moment metabolic control of glucose and allow them to achieve insulin independence. However, two major problems need to be overcome: (1 detrimental immune responses, including inflammation induced by the islet isolation/transplantation procedure, recurrence autoimmunity, and allorejection, can cause graft loss and (2 inadequate numbers of organ donors. Several gene therapy approaches and pharmaceutical treatments have been demonstrated to prolong the survival of pancreatic islet grafts in animal models; however, the clinical applications need to be investigated further. In addition, for an alternative source of pancreatic β-cell replacement therapy, the ex vivo generation of insulin-secreting cells from diverse origins of stem/progenitor cells has become an attractive option in regenerative medicine. This paper focuses on the genetic manipulation of islets during transplantation therapy and summarizes current strategies to obtain functional insulin-secreting cells from stem/progenitor cells.

Expansion of Adult Human Pancreatic Tissue Yields Organoids Harboring Progenitor Cells with Endocrine Differentiation Potential

Directory of Open Access Journals (Sweden)

Cindy J.M. Loomans

2018-03-01

Full Text Available Summary: Generating an unlimited source of human insulin-producing cells is a prerequisite to advance β cell replacement therapy for diabetes. Here, we describe a 3D culture system that supports the expansion of adult human pancreatic tissue and the generation of a cell subpopulation with progenitor characteristics. These cells display high aldehyde dehydrogenase activity (ALDHhi, express pancreatic progenitors markers (PDX1, PTF1A, CPA1, and MYC, and can form new organoids in contrast to ALDHlo cells. Interestingly, gene expression profiling revealed that ALDHhi cells are closer to human fetal pancreatic tissue compared with adult pancreatic tissue. Endocrine lineage markers were detected upon in vitro differentiation. Engrafted organoids differentiated toward insulin-positive (INS+ cells, and circulating human C-peptide was detected upon glucose challenge 1 month after transplantation. Engrafted ALDHhi cells formed INS+ cells. We conclude that adult human pancreatic tissue has potential for expansion into 3D structures harboring progenitor cells with endocrine differentiation potential. : In the context of β cell replacement therapy for diabetes, de Koning and colleagues describe a 3D culture platform that supports ex vivo expansion of human pancreatic tissue as organoids. These organoids harbor a subpopulation of ALDHhi cells that display proliferative capacity and can differentiate to an endocrine fate. Keywords: pancreas, organoid, human, ALDH, endocrine differentiation, beta cells, insulin, progenitor, fetal, diabetes

Insulinotropic and anti-inflammatory effects of rosiglitazone in experimental autoimmune diabetes.

Science.gov (United States)

Awara, Wageh M; el-Sisi, Alaa E; el-Refaei, Mohamed; el-Naa, Mona M; el-Desoky, Karima

2005-01-01

Cytokines and nitric oxide (NO) are involved in the pathogenesis of autoimmune diabetes mellitus (DM). Rosiglitazone is an insulin-sensitizing drug that is a ligand for the nuclear receptor peroxisome proliferator-activated receptor-gamma (PPAR-gamma). The anti-inflammatory and immunomodulating properties of PPAR-gamma have been documented. The aim of this study is to investigate the effectiveness of rosiglitazone in autoimmune DM and to clarify the possible mechanism(s) involved. Autoimmune DM was induced in adult male Balb/c mice by co-administration of cyclosporin A and multiple low doses of streptozotocin. Diabetic mice were treated daily with rosiglitazone (7 mg/kg, p.o.) for 21 days. Blood glucose level (BGL), serum insulin level and pancreatic levels of tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and NO were measured. Histopathological examination and immunohistochemical determination of CD4 and CD8 T lymphocytes in the pancreatic islets were performed. In addition, analysis of pancreatic protein expression was carried out. The results showed that rosiglitazone treatment resulted in a significant decrease in the BGL and the pancreatic levels of TNF-alpha, IFN-gamma and NO compared to diabetic mice. The serum insulin level was significantly increased after rosiglitazone treatment compared to diabetic mice. The destroyed pancreatic islets were regenerated and became free from both CD4 and CD8 T cells after treatment. Furthermore, many changes in pancreatic protein expression were observed. These results suggest that rosiglitazone has a beneficial effect in the treatment of autoimmune diabetes, an effect that seemed to be a secondary consequence of its anti-inflammatory and immunomodulating properties and might be reflected at the level of protein expression.

Treatment of autoimmune pancreatitis with the anecdotes of the first report.

Science.gov (United States)

Kamisawa, Terumi; Takeuchi, Tadashi

2012-01-01

The first case that led researchers to put forward a new concept of autoimmune pancreatitis (AIP) was treated with steroids by gastroenterologists in Tokyo Women's Medical University. It is important to differentiate AIP from pancreatic cancer before treatment with steroids is started. Today, steroids are standard therapy for AIP worldwide. In the Japanese consensus guidelines, steroid therapy is indicated for symptomatic AIP. After management of glucose levels and obstructive jaundice, oral prednisolone is initiated at 0.6 mg/kg/day for 2-4 weeks and is gradually tapered to a maintenance dose of 2.5-5 mg/day over 2-3 months. To prevent relapse, maintenance therapy with low-dose prednisolone is used. For relapsed AIP, readministration or increased doses of steroids are effective. The presence of proximal bile duct stenosis and elevated serum IgG4 levels may be predictive of relapse of AIP. It is necessary to verify the validity of the Japanese regimen of steroid therapy for AIP. The necessity, drugs, and duration of maintenance therapy for AIP need to be clarified by prospective studies.

D-saccharic acid-1,4-lactone ameliorates alloxan-induced diabetes mellitus and oxidative stress in rats through inhibiting pancreatic beta-cells from apoptosis via mitochondrial dependent pathway

Energy Technology Data Exchange (ETDEWEB)

Bhattacharya, Semantee [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Manna, Prasenjit [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India); Gachhui, Ratan [Department of Life Sciences and Biotechnology, Jadavpur University, 188, Raja S C Mullick Road, Kolkata 700 032 (India); Sil, Parames C., E-mail: parames@bosemain.boseinst.ac.in [Division of Molecular Medicine, Bose Institute, P-1/12, CIT Scheme VII M, Kolkata-700054 (India)

2011-12-15

Oxidative stress plays a vital role in diabetic complications. To suppress the oxidative stress mediated damage in diabetic pathophysiology, a special focus has been given on naturally occurring antioxidants present in normal diet. D-saccharic acid 1,4-lactone (DSL), a derivative of D-glucaric acid, is present in many dietary plants and is known for its detoxifying and antioxidant properties. The aim of the present study was to evaluate the beneficial role of DSL against alloxan (ALX) induced diabetes in the pancreas tissue of Swiss albino rats. A dose-dependent study for DSL (20-120 mg/kg body weight) was carried out to find the effective dose of the compound in ALX-induced diabetic rats. ALX exposure elevated the blood glucose, glycosylated Hb, decreased the plasma insulin and disturbed the intra-cellular antioxidant machineries whereas oral administration of DSL at a dose of 80 mg/kg body weight restored these alterations close to normal. Investigating the mechanism of the protective activity of DSL we observed that it prevented the pancreatic {beta}-cell apoptosis via mitochondria-dependent pathway. Results showed decreased mitochondrial membrane potential, enhanced cytochrome c release in the cytosol and reciprocal regulation of Bcl-2 family proteins in the diabetic rats. These events were also found to be associated with increased level of Apaf-1, caspase 9, and caspase 3 that ultimately led to pancreatic {beta}-cell apoptosis. DSL treatment, however, counteracted these changes. In conclusion, DSL possesses the capability of ameliorating the oxidative stress in ALX-induced diabetes and thus could be a promising approach in lessening diabetic complications. Highlights: Black-Right-Pointing-Pointer Oxidative stress is suggested as a key event in the pathogenesis of diabetes. Black-Right-Pointing-Pointer D-saccharic acid 1,4-lactone (DSL) reduces the alloxan-induced diabetes mellitus. Black-Right-Pointing-Pointer DSL normalizes cellular antioxidant machineries

Considerations for Defining Cytokine Dose, Duration, and Milieu That Are Appropriate for Modeling Chronic Low-Grade Inflammation in Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Craig S. Nunemaker

2016-01-01

Full Text Available Proinflammatory cytokines have been implicated in the pathophysiology of both type 1 diabetes (T1D and type 2 diabetes (T2D. T1D is an autoimmune disease involving the adaptive immune system responding to pancreatic beta-cells as antigen-presenting cells. This attracts immune cells that surround pancreatic islets (insulitis and secrete cytokines, such as IL-1beta, IFN-gamma, and TNF-alpha, in close proximity to pancreatic beta-cells. In contrast, there is little evidence for such a focused autoimmune response in T2D. Instead, the innate immune system, which responds to cellular damage and pathogens, appears to play a key role. There are three major sources of proinflammatory cytokines that may impact islet/beta-cell function in T2D: (1 from islet cells, (2 from increased numbers of intraislet macrophages/immune cells, and (3 from increased circulating levels of proinflammatory cytokines due to obesity, presumably coming from inflamed adipose tissue. These differences between T1D and T2D are reflected by significant differences in the cytokine concentration, duration, and milieu. This review focuses on chronic versus acute cytokine action, cytokine concentrations, and cytokine milieu from the perspective of the pancreatic islet in T2D. We conclude that new cytokine models may be needed to reflect the pathophysiology of T2D more effectively than what are currently employed.

Central infusion of leptin improves insulin resistance and suppresses beta-cell function, but not beta-cell mass, primarily through the sympathetic nervous system in a type 2 diabetic rat model.

Science.gov (United States)

Park, Sunmin; Ahn, Il Sung; Kim, Da Sol

2010-06-05

We investigated whether hypothalamic leptin alters beta-cell function and mass directly via the sympathetic nervous system (SNS) or indirectly as the result of altered insulin resistant states. The 90% pancreatectomized male Sprague Dawley rats had sympathectomy into the pancreas by applying phenol into the descending aorta (SNSX) or its sham operation (Sham). Each group was divided into two sections, receiving either leptin at 300ng/kgbw/h or artificial cerebrospinal fluid (aCSF) via intracerebroventricular (ICV) infusion for 3h as a short-term study. After finishing the infusion study, ICV leptin (3mug/kg bw/day) or ICV aCSF (control) was infused in rats fed 30 energy % fat diets by osmotic pump for 4weeks. At the end of the long-term study, glucose-stimulated insulin secretion and islet morphometry were analyzed. Acute ICV leptin administration in Sham rats, but not in SNSX rats, suppressed the first- and second-phase insulin secretion at hyperglycemic clamp by about 48% compared to the control. Regardless of SNSX, the 4-week administration of ICV leptin improved glucose tolerance during oral glucose tolerance tests and insulin sensitivity at hyperglycemic clamp, compared to the control, while it suppressed second-phase insulin secretion in Sham rats but not in SNSX rats. However, the pancreatic beta-cell area and mass were not affected by leptin and SNSX, though ICV leptin decreased individual beta-cell size and concomitantly increased beta-cell apoptosis in Sham rats. Leptin directly decreases insulin secretion capacity mainly through the activation of SNS without modulating pancreatic beta-cell mass.

Induction of insulin secretion in engineered liver cells by nitric oxide

Directory of Open Access Journals (Sweden)

Özcan Sabire

2007-10-01

Full Text Available Abstract Background Type 1 Diabetes Mellitus results from an autoimmune destruction of the pancreatic beta cells, which produce insulin. The lack of insulin leads to chronic hyperglycemia and secondary complications, such as cardiovascular disease. The currently approved clinical treatments for diabetes mellitus often fail to achieve sustained and optimal glycemic control. Therefore, there is a great interest in the development of surrogate beta cells as a treatment for type 1 diabetes. Normally, pancreatic beta cells produce and secrete insulin only in response to increased blood glucose levels. However in many cases, insulin secretion from non-beta cells engineered to produce insulin occurs in a glucose-independent manner. In the present study we engineered liver cells to produce and secrete insulin and insulin secretion can be stimulated via the nitric oxide pathway. Results Expression of either human insulin or the beta cell specific transcription factors PDX-1, NeuroD1 and MafA in the Hepa1-6 cell line or primary liver cells via adenoviral gene transfer, results in production and secretion of insulin. Although, the secretion of insulin is not significantly increased in response to high glucose, treatment of these engineered liver cells with L-arginine stimulates insulin secretion up to three-fold. This L-arginine-mediated insulin release is dependent on the production of nitric oxide. Conclusion Liver cells can be engineered to produce insulin and insulin secretion can be induced by treatment with L-arginine via the production of nitric oxide.

Insulin Resistance and Impaired Pancreatic β-Cell Function in Adult Offspring of Women With Diabetes in Pregnancy

DEFF Research Database (Denmark)

Kelstrup, Louise; Damm, Peter; Mathiesen, Elisabeth R

2013-01-01

Context:Offspring of women with diabetes during pregnancy have increased risk of glucose intolerance in adulthood, but the underlying mechanisms are unknown.Objective:We aimed to investigate effects of intrauterine hyperglycemia on insulin secretion and - action in adult offspring of mothers...... a standard oral glucose tolerance test (120 minutes, 75 gram glucose). Pancreatic beta-cell function taking the prevailing insulin sensitivity into account was estimated by disposition indices.Results:Both groups of offspring exposed during pregnancy to either maternal gestational diabetes or type 1 diabetes.......005).Conclusion:Reduced insulin sensitivity as well as impaired pancreatic beta cell function may contribute to the increased risk of glucose intolerance among adult offspring born to women with diabetes during pregnancy....

IgG4-Seronegative Autoimmune Pancreatitis and Sclerosing Cholangitis

Directory of Open Access Journals (Sweden)

Allon Kahn

2015-01-01

Full Text Available IgG4-related disease is a relatively novel clinical entity whose gastrointestinal manifestations include type 1 autoimmune pancreatitis (AIP and IgG4-associated sclerosing cholangitis. The presence of elevated serum IgG4 is suggestive but not essential for the diagnosis of type 1 AIP and is a pervasive feature of the proposed diagnostic criteria. The differential diagnosis of type 1 AIP includes malignant conditions, emphasizing the importance of a deliberate, comprehensive evaluation. Management of patients with a suggestive clinical presentation, but without serum IgG4 elevation, is difficult. Here we present three cases of IgG4-seronegative AIP and sclerosing cholangitis that responded to empiric steroid therapy and discuss approach considerations. These cases demonstrate the value of meticulous application of existing diagnostic algorithms to achieve a clinical diagnosis and avoid surgical intervention.

Oxidative Metabolism Genes Are Not Responsive to Oxidative Stress in Rodent Beta Cell Lines

Directory of Open Access Journals (Sweden)

Faer Morrison

2012-01-01

Full Text Available Altered expression of oxidative metabolism genes has been described in the skeletal muscle of individuals with type 2 diabetes. Pancreatic beta cells contain low levels of antioxidant enzymes and are particularly susceptible to oxidative stress. In this study, we explored the effect of hyperglycemia-induced oxidative stress on a panel of oxidative metabolism genes in a rodent beta cell line. We exposed INS-1 rodent beta cells to low (5.6 mmol/L, ambient (11 mmol/L, and high (28 mmol/L glucose conditions for 48 hours. Increases in oxidative stress were measured using the fluorescent probe dihydrorhodamine 123. We then measured the expression levels of a panel of 90 oxidative metabolism genes by real-time PCR. Elevated reactive oxygen species (ROS production was evident in INS-1 cells after 48 hours (P<0.05. TLDA analysis revealed a significant (P<0.05 upregulation of 16 of the 90 genes under hyperglycemic conditions, although these expression differences did not reflect differences in ROS. We conclude that although altered glycemia may influence the expression of some oxidative metabolism genes, this effect is probably not mediated by increased ROS production. The alterations to the expression of oxidative metabolism genes previously observed in human diabetic skeletal muscle do not appear to be mirrored in rodent pancreatic beta cells.

Pancreas-Specific Sirt1-Deficiency in Mice Compromises Beta-Cell Function without Development of Hyperglycemia.

Science.gov (United States)

Pinho, Andreia V; Bensellam, Mohammed; Wauters, Elke; Rees, Maxine; Giry-Laterriere, Marc; Mawson, Amanda; Ly, Le Quan; Biankin, Andrew V; Wu, Jianmin; Laybutt, D Ross; Rooman, Ilse

2015-01-01

Sirtuin 1 (Sirt1) has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear. This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1Cre; Sirt1ex4F/F mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas. We found that in the Pdx1Cre; Sirt1ex4F/F mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2a2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r) as well as a marked down regulation of endoplasmic reticulum (ER) chaperones that participate in the Unfolded Protein Response (UPR) pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP) cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas. This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncovered a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted.

Pancreas-Specific Sirt1-Deficiency in Mice Compromises Beta-Cell Function without Development of Hyperglycemia.

Directory of Open Access Journals (Sweden)

Andreia V Pinho

Full Text Available Sirtuin 1 (Sirt1 has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear.This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1Cre; Sirt1ex4F/F mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas.We found that in the Pdx1Cre; Sirt1ex4F/F mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2a2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r as well as a marked down regulation of endoplasmic reticulum (ER chaperones that participate in the Unfolded Protein Response (UPR pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas.This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncovered a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted.

Efficient Generation of Glucose-Responsive Beta Cells from Isolated GP2+ Human Pancreatic Progenitors

Directory of Open Access Journals (Sweden)

Jacqueline Ameri

2017-04-01

Full Text Available Stem cell-based therapy for type 1 diabetes would benefit from implementation of a cell purification step at the pancreatic endoderm stage. This would increase the safety of the final cell product, allow the establishment of an intermediate-stage stem cell bank, and provide a means for upscaling β cell manufacturing. Comparative gene expression analysis revealed glycoprotein 2 (GP2 as a specific cell surface marker for isolating pancreatic endoderm cells (PECs from differentiated hESCs and human fetal pancreas. Isolated GP2+ PECs efficiently differentiated into glucose responsive insulin-producing cells in vitro. We found that in vitro PEC proliferation declines due to enhanced expression of the cyclin-dependent kinase (CDK inhibitors CDKN1A and CDKN2A. However, we identified a time window when reducing CDKN1A or CDKN2A expression increased proliferation and yield of GP2+ PECs. Altogether, our results contribute tools and concepts toward the isolation and use of PECs as a source for the safe production of hPSC-derived β cells.

Pancreatic beta-cell function is a stronger predictor of changes in glycemic control after an aerobic exercise intervention than insulin sensitivity

DEFF Research Database (Denmark)

Solomon, Thomas; Malin, Steven K; Karstoft, Kristian

2013-01-01

glucose-stimulated insulin secretion (GSIS), and disposition index (DI) were measured following 12-16-weeks of aerobic exercise training. Regression analyses were used to identify relationships between variables.ResultsFollowing training, 86% of subjects increased VO2max and lost weight. HbA1c, fasting......ContextUnderstanding inter-subject variability in glycemic control following exercise training will help individualize treatment.ObjectiveTo determine whether this variability is related to training-induced changes in insulin sensitivity or pancreatic beta-cell function.Design, Setting....... Training increased first- and second-phase DI in 83% and 74% of subjects. Training-induced changes in glycemic control were related to changes in GSIS (P...

Lactate overrides central nervous but not beta-cell glucose sensing in humans.

Science.gov (United States)

Schmid, Sebastian M; Jauch-Chara, Kamila; Hallschmid, Manfred; Oltmanns, Kerstin M; Peters, Achim; Born, Jan; Schultes, Bernd

2008-12-01

Lactate has been shown to serve as an alternative energy substrate in the central nervous system and to interact with hypothalamic glucose sensors. On the background of marked similarities between central nervous and beta-cell glucose sensing, we examined whether lactate also interacts with pancreatic glucose-sensing mechanisms in vivo. The effects of intravenously infused lactate vs placebo (saline) on central nervous and pancreatic glucose sensing were assessed during euglycemic and hypoglycemic clamp experiments in 10 healthy men. The release of neuroendocrine counterregulatory hormones during hypoglycemia was considered to reflect central nervous glucose sensing, whereas endogenous insulin secretion as assessed by serum C-peptide levels served as an indicator of pancreatic beta-cell glucose sensing. Lactate infusion blunted the counterregulatory hormonal responses to hypoglycemia, in particular, the release of epinephrine (P = .007) and growth hormone (P = .004), so that higher glucose infusion rates (P = .012) were required to maintain the target blood glucose levels. In contrast, the decrease in C-peptide concentrations during the hypoglycemic clamp remained completely unaffected by lactate (P = .60). During euglycemic clamp conditions, lactate infusion did not affect the concentrations of C-peptide and of counterregulatory hormones, with the exception of norepinephrine levels that were lower during lactate than saline infusion (P = .049) independently of the glycemic condition. Data indicate that glucose sensing of beta-cells is specific to glucose, whereas glucose sensing at the central nervous level can be overridden by lactate, reflecting the brain's ability to rely on lactate as an alternative major energy source.

Interactions between the metabolism of L-leucine and D-glucose in the pancreatic. beta. -cells

Energy Technology Data Exchange (ETDEWEB)

Gylfe, E; Sehlin, J [Umeaa Univ. (Sweden). Dept. of Histology

1976-01-01

..beta..-cell-rich pancreatic islets microdissected from obese-hyperglycemic mice were used to study interactions between the metabolism of L-leucine and D-glucose. L-leucine reduced the islet content of aspartic acid whereas D-glucose, when added to L-leucine-incubated islets, increased the contents of aspartic acid and ..gamma..-aminobutyric acid (GABA). D-glucose also increased the incorporation of L-leucine carbon into aspartic acid, GABA and glutamic acid, suggesting stimulation of a malate shuttle mechanism. When expressed per mole of the individual amino acids, the incorporation of L-leucine carbon into GABA was 2.5 - 4 times higher than into glutamic acid indicating intracellular compartmentation of the latter amino acid. Both L-leucine and D-leucine stimulated /sup 14/CO/sub 2/ production from /sup 14/C-labelled D-glucose. L-leucine did not affect /sup 3/H/sub 2/O production from tritiated D-glucose. The present data do not indicate a role of other amino acids or D-glucose in L-leucine-stimulated insulin release.

Protective role of complement C3 against cytokine-mediated beta cell apoptosis

DEFF Research Database (Denmark)

Dos Santos, R. S.; Marroqui, L.; Grieco, F. A.

2017-01-01

Background and aims: Type 1 diabetes is a chronic autoimmune disease characterized by pancreatic islet inflammation and β-cell destruction by pro-inflammatory cytokines and other mediators. The complement system, a major component of the immune system, has been recently shown to also act in metab...... in metabolic organs, such as liver, adipose tissue, and pancreas. In the present study we identified complement C3 as an important hub of a cytokine-modified complement network in human islets and characterized the role of C3 in β-cell survival....

Plasticity of adult human pancreatic duct cells by neurogenin3-mediated reprogramming.

Directory of Open Access Journals (Sweden)

Nathalie Swales

Full Text Available AIMS/HYPOTHESIS: Duct cells isolated from adult human pancreas can be reprogrammed to express islet beta cell genes by adenoviral transduction of the developmental transcription factor neurogenin3 (Ngn3. In this study we aimed to fully characterize the extent of this reprogramming and intended to improve it. METHODS: The extent of the Ngn3-mediated duct-to-endocrine cell reprogramming was measured employing genome wide mRNA profiling. By modulation of the Delta-Notch signaling or addition of pancreatic endocrine transcription factors Myt1, MafA and Pdx1 we intended to improve the reprogramming. RESULTS: Ngn3 stimulates duct cells to express a focused set of genes that are characteristic for islet endocrine cells and/or neural tissues. This neuro-endocrine shift however, is incomplete with less than 10% of full duct-to-endocrine reprogramming achieved. Transduction of exogenous Ngn3 activates endogenous Ngn3 suggesting auto-activation of this gene. Furthermore, pancreatic endocrine reprogramming of human duct cells can be moderately enhanced by inhibition of Delta-Notch signaling as well as by co-expressing the transcription factor Myt1, but not MafA and Pdx1. CONCLUSIONS/INTERPRETATION: The results provide further insight into the plasticity of adult human duct cells and suggest measurable routes to enhance Ngn3-mediated in vitro reprogramming protocols for regenerative beta cell therapy in diabetes.

Treatment of Autoimmune Pancreatitis with the Anecdotes of the First Report

Directory of Open Access Journals (Sweden)

Terumi Kamisawa

2012-01-01

Full Text Available The first case that led researchers to put forward a new concept of autoimmune pancreatitis (AIP was treated with steroids by gastroenterologists in Tokyo Women’s Medical University. It is important to differentiate AIP from pancreatic cancer before treatment with steroids is started. Today, steroids are standard therapy for AIP worldwide. In the Japanese consensus guidelines, steroid therapy is indicated for symptomatic AIP. After management of glucose levels and obstructive jaundice, oral prednisolone is initiated at 0.6 mg/kg/day for 2–4 weeks and is gradually tapered to a maintenance dose of 2.5–5 mg/day over 2-3 months. To prevent relapse, maintenance therapy with low-dose prednisolone is used. For relapsed AIP, readministration or increased doses of steroids are effective. The presence of proximal bile duct stenosis and elevated serum IgG4 levels may be predictive of relapse of AIP. It is necessary to verify the validity of the Japanese regimen of steroid therapy for AIP. The necessity, drugs, and duration of maintenance therapy for AIP need to be clarified by prospective studies.

Gatekeepers of pancreas: TEAD and YAP

OpenAIRE

Rodríguez Seguí, Santiago Andrés; Bessa, José

2017-01-01

The pancreas hosts some of the most debilitating and deadly diseases, including pancreatic cancer and diabetes mellitus. In autoimmune diabetes, for example, there is a massive destruction of the insulin producing cells of the pancreas. Pancreatic developmental defects can also result in a deficit of this cell type. To revert these important pancreatic diseases, researchers are currently trying to artificially generate insulin producing beta-cells for implantation and, in this way, suppress i...

Chronic Pancreatitis.

Science.gov (United States)

Stram, Michelle; Liu, Shu; Singhi, Aatur D

2016-12-01

Chronic pancreatitis is a debilitating condition often associated with severe abdominal pain and exocrine and endocrine dysfunction. The underlying cause is multifactorial and involves complex interaction of environmental, genetic, and/or other risk factors. The pathology is dependent on the underlying pathogenesis of the disease. This review describes the clinical, gross, and microscopic findings of the main subtypes of chronic pancreatitis: alcoholic chronic pancreatitis, obstructive chronic pancreatitis, paraduodenal ("groove") pancreatitis, pancreatic divisum, autoimmune pancreatitis, and genetic factors associated with chronic pancreatitis. As pancreatic ductal adenocarcinoma may be confused with chronic pancreatitis, the main distinguishing features between these 2 diseases are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

MicroRNA-29b modulates innate and antigen-specific immune responses in mouse models of autoimmunity.

Directory of Open Access Journals (Sweden)

Apolline Salama

Full Text Available In addition to important regulatory roles in gene expression through RNA interference, it has recently been shown that microRNAs display immune stimulatory effects through direct interaction with receptors of innate immunity of the Toll-like receptor family, aggravating neuronal damage and tumour growth. Yet no evidence exists on consequences of microRNA immune stimulatory actions in the context of an autoimmune disease. Using microRNA analogues, we here show that pancreatic beta cell-derived microRNA sequences induce pro-inflammatory (TNFa, IFNa, IL-12, IL-6 or suppressive (IL-10 cytokine secretion by primary mouse dendritic cells in a sequence-dependent manner. For miR-29b, immune stimulation in RAW264.7 macrophages involved the endosomal Toll-like receptor-7, independently of the canonical RNA interference pathway. In vivo, the systemic delivery of miR-29b activates CD11b+B220- myeloid and CD11b-B220+ plasmacytoid dendritic cells and induces IFNa, TNFa and IL-6 production in the serum of recipient mice. Strikingly, in a murine model of adoptive transfer of autoimmune diabetes, miR-29b reduces the cytolytic activity of transferred effector CD8+ T-cells, insulitis and disease incidence in a single standalone intervention. Endogenous miR-29b, spontaneously released from beta-cells within exosomes, stimulates TNFa secretion from spleen cells isolated from diabetes-prone NOD mice in vitro. Hence, microRNA sequences modulate innate and ongoing adaptive immune responses raising the question of their potential role in the breakdown of tolerance and opening up new applications for microRNA-based immune therapy.

Pancreatic Fat Is Associated With Metabolic Syndrome and Visceral Fat but Not Beta-Cell Function or Body Mass Index in Pediatric Obesity.

Science.gov (United States)

Staaf, Johan; Labmayr, Viktor; Paulmichl, Katharina; Manell, Hannes; Cen, Jing; Ciba, Iris; Dahlbom, Marie; Roomp, Kirsten; Anderwald, Christian-Heinz; Meissnitzer, Matthias; Schneider, Reinhard; Forslund, Anders; Widhalm, Kurt; Bergquist, Jonas; Ahlström, Håkan; Bergsten, Peter; Weghuber, Daniel; Kullberg, Joel

2017-03-01

Adolescents with obesity have increased risk of type 2 diabetes and metabolic syndrome (MetS). Pancreatic fat has been related to these conditions; however, little is known about associations in pediatric obesity. The present study was designed to explore these associations further. We examined 116 subjects, 90 with obesity. Anthropometry, MetS, blood samples, and oral glucose tolerance tests were assessed using standard techniques. Pancreatic fat fraction (PFF) and other fat depots were quantified using magnetic resonance imaging. The PFF was elevated in subjects with obesity. No association between PFF and body mass index-standard deviation score (BMI-SDS) was found in the obesity subcohort. Pancreatic fat fraction correlated to Insulin Secretion Sensitivity Index-2 and Homeostatic Model Assessment of Insulin Resistance in simple regression; however, when using adjusted regression and correcting for BMI-SDS and other fat compartments, PFF correlated only to visceral adipose tissue and fasting glucose. Highest levels of PFF were found in subjects with obesity and MetS. In adolescents with obesity, PFF is elevated and associated to MetS, fasting glucose, and visceral adipose tissue but not to beta-cell function, glucose tolerance, or BMI-SDS. This study demonstrates that conclusions regarding PFF and its associations depend on the body mass features of the cohort.

Efficient Generation of NKX6-1+ Pancreatic Progenitors from Multiple Human Pluripotent Stem Cell Lines

Directory of Open Access Journals (Sweden)

M. Cristina Nostro

2015-04-01

Full Text Available Human pluripotent stem cells (hPSCs represent a renewable source of pancreatic beta cells for both basic research and therapeutic applications. Given this outstanding potential, significant efforts have been made to identify the signaling pathways that regulate pancreatic development in hPSC differentiation cultures. In this study, we demonstrate that the combination of epidermal growth factor (EGF and nicotinamide signaling induces the generation of NKX6-1+ progenitors from all hPSC lines tested. Furthermore, we show that the size of the NKX6-1+ population is regulated by the duration of treatment with retinoic acid, fibroblast growth factor 10 (FGF10, and inhibitors of bone morphogenetic protein (BMP and hedgehog signaling pathways. When transplanted into NOD scid gamma (NSG recipients, these progenitors differentiate to give rise to exocrine and endocrine cells, including monohormonal insulin+ cells. Together, these findings provide an efficient and reproducible strategy for generating highly enriched populations of hPSC-derived beta cell progenitors for studies aimed at further characterizing their developmental potential in vivo and deciphering the pathways that regulate their maturation in vitro.

Serum Immunoglobulin G4 in Discriminating Autoimmune Pancreatitis From Pancreatic Cancer: A Diagnostic Meta-analysis.

Science.gov (United States)

Dai, Cong; Cao, Qin; Jiang, Min; Sun, Ming-Jun

2018-03-01

Differentiation between autoimmune pancreatitis (AIP) and pancreatic cancer (PC) is a clinical challenge. Emerging published data on the accuracy of serum immunoglobulin G4 (IgG4) for the differential diagnosis between AIP and PC are inconsistent. The objective of our study was to perform a meta-analysis evaluating the clinical utility of serum IgG4 in the differential diagnosis between AIP and PC. We performed a systematic literature search of multiple electronic databases. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. Random-effects model was used to summarize the diagnostic odds ratio and other measures of accuracy. Eleven studies comprising 523 AIP patients and 771 PC patients were included in the meta-analysis. The summary estimates for serum IgG4 in distinguishing AIP from PC were as follows: diagnostic odds ratio, 57.30 (95% confidence interval [CI], 23.17-141.67); sensitivity, 0.72 (95% CI, 0.68-0.76); specificity, 0.93 (95% CI, 0.91-0.94). The area under the curve of serum IgG4 in distinguishing AIP from PC was 0.9200. Our meta-analysis found that serum IgG4 has high specificity and relatively low sensitivity in the differential diagnosis between AIP and PC. Therefore, serum IgG4 is useful in distinguishing AIP from PC.

cPLA2alpha-evoked formation of arachidonic acid and lysophospholipids is required for exocytosis in mouse pancreatic beta-cells

DEFF Research Database (Denmark)

Juhl, Kirstine; Høy, Marianne; Olsen, Hervør L

2003-01-01

Using capacitance measurements, we investigated the effects of intracellularly applied recombinant human cytosolic phospholipase A2 (cPLA2alpha) and its lipolytic products arachidonic acid and lysophosphatidylcholine on Ca2+-dependent exocytosis in single mouse pancreatic beta-cells. cPLA2alpha...... from 70-80 to 280-300. cPLA2alpha-stimulated exocytosis was antagonized by the specific cPLA2 inhibitor AACOCF3. Ca2+-evoked exocytosis was reduced by 40% in cells treated with AACOCF3 or an antisense oligonucleotide against cPLA2alpha. The action of cPLA2alpha was mimicked by a combination...... of arachidonic acid and lysophosphatidylcholine (470% stimulation) in which each compound alone doubled the exocytotic response. Priming of insulin-containing secretory granules has been reported to involve Cl- uptake through ClC-3 Cl- channels. Accordingly, the stimulatory action of cPLA2alpha was inhibited...

Stress proteins, autoimmunity, and autoimmune disease.

Science.gov (United States)

Winfield, J B; Jarjour, W N

1991-01-01

At birth, the immune system is biased toward recognition of microbial antigens in order to protect the host from infection. Recent data suggest that an important initial line of defense in this regard involves autologous stress proteins, especially conserved peptides of hsp60, which are presented to T cells bearing gamma delta receptors by relatively nonpolymorphic class lb molecules. Natural antibodies may represent a parallel B cell mechanism. Through an evolving process of "physiological" autoreactivity and selection by immunodominant stress proteins common to all prokaryotes, B and T cell repertoires expand during life to meet the continuing challenge of infection. Because stress proteins of bacteria are homologous with stress proteins of the host, there exists in genetically susceptible individuals a constant risk of autoimmune disease due to failure of mechanisms for self-nonself discrimination. That stress proteins actually play a role in autoimmune processes is supported by a growing body of evidence which, collectively, suggests that autoreactivity in chronic inflammatory arthritis involves, at least initially, gamma delta cells which recognize epitopes of the stress protein hsp60. Alternate mechanisms for T cell stimulation by stress proteins undoubtedly also exist, e.g., molecular mimicry of the DR beta third hypervariable region susceptibility locus for rheumatoid arthritis by a DnaJ stress protein epitope in gram-negative bacteria. While there still is confusion with respect to the most relevant stress protein epitopes, a central role for stress proteins in the etiology of arthritis appears likely. Furthermore, insight derived from the work thus far in adjuvant-induced arthritis already is stimulating analyses of related phenomena in autoimmune diseases other than those involving joints. Only limited data are available in the area of humoral autoimmunity to stress proteins. Autoantibodies to a number of stress proteins have been identified in SLE and

Dendritic Cells Promote Pancreatic Viability in Mice with Acute Pancreatitis

Science.gov (United States)

Bedrosian, Andrea S.; Nguyen, Andrew H.; Hackman, Michael; Connolly, Michael K.; Malhotra, Ashim; Ibrahim, Junaid; Cieza-Rubio, Napoleon E.; Henning, Justin R.; Barilla, Rocky; Rehman, Adeel; Pachter, H. Leon; Medina-Zea, Marco V.; Cohen, Steven M.; Frey, Alan B.; Acehan, Devrim; Miller, George

2011-01-01

Background & Aims Acute pancreatitis increases morbidity and mortality from organ necrosis by mechanisms that are incompletely understood. Dendritic cells (DCs) can promote or suppress inflammation, depending on their subtype and context. We investigated the roles of DC in development of acute pancreatitis. Methods Acute pancreatitis was induced in CD11c.DTR mice using caerulein or L-arginine; DCs were depleted by administration of diphtheria toxin. Survival was analyzed using Kaplan-Meier analysis. Results Numbers of MHC II+CD11c+DC increased 100-fold in pancreas of mice with acute pancreatitis, to account for nearly 15% of intra-pancreatic leukocytes. Intra-pancreatic DC acquired an immune phenotype in mice with acute pancreatitis; they expressed higher levels of MHC II and CD86 and increased production of interleukin-6, membrane cofactor protein (MCP)-1, and tumor necrosis factor (TNF)-α. However, rather than inducing an organ-destructive inflammatory process, DC were required for pancreatic viability; the exocrine pancreas died in mice that were depleted of DC and challenged with caerulein or L-arginine. All mice with pancreatitis that were depleted of DC died from acinar cell death within 4 days. Depletion of DC from mice with pancreatitis resulted in neutrophil infiltration and increased levels of systemic markers of inflammation. However, the organ necrosis associated with depletion of DC did not require infiltrating neutrophils, activation of NF-κB, or signaling by mitogen-activated protein kinase or TNF-α. Conclusions DC are required for pancreatic viability in mice with acute pancreatitis and might protect organs against cell stress. PMID:21801698

A Patient with Autoimmune Pancreatitis Type 1 with Previously Known Lymphadenopathy, Both in the Context of IgG4-related Disease.

Science.gov (United States)

Alidjan, Fazil M; Karim, Faiz; Verdijk, Rob M; van Esser, Joost W; van Heerde, Marianne J

2015-11-05

Autoimmune pancreatitis (AIP) is an important clinical pathologic concept of IgG-4-related disease. AIP is a rare cause of chronic pancreatitis, characterized by a fibroinflammatory process by lymphoplasmacytic infiltrates, storiform fibrosis, obliterative phlebitis, and increased IgG4+ plasma cells, leading to dysfunction of the pancreas. Affected patients with AIP frequently have disease affecting other organs or sites with similar histologic changes, elevated IgG4+ plasma cell infiltrate, and good response to corticosteroid therapy. These diseases often are not limited to the pancreas and the pancreas may not be involved at all. We report a 62-year-old man with obstructive jaundice with pre-existent submandibular lymphadenopathy. Diagnosis of AIP was based on diagnostic criteria by the HISORT-criteria in combination with elevated IgG-4 serum levels. CT revealed a focal enlargement of the head of the pancreas, as well as mesenteric peripancreatic and mediastinal lymphadenopathy. He was treated with high-dose steroid in combination with azathioprine and showed good clinical response. We report a case with pre-existent submandibular lymphadenopathy and obstructive jaundice based on AIP type 1, both in the context of IgG4-related disease.

Bone morphogenetic protein 4 inhibits insulin secretion from rodent beta cells through regulation of calbindin1 expression and reduced voltage-dependent calcium currents

DEFF Research Database (Denmark)

Christensen, Gitte L.; Jacobsen, Maria L. B.; Wendt, Anna

2015-01-01

AIMS/HYPOTHESIS: Type 2 diabetes is characterised by progressive loss of pancreatic beta cell mass and function. Therefore, it is of therapeutic interest to identify factors with the potential to improve beta cell proliferation and insulin secretion. Bone morphogenetic protein 4 (BMP4) expression...

Pancreatic effect of andrographolide isolated from Andrographis paniculata (Burm. f.) Nees.

Science.gov (United States)

Nugroho, Agung Endro; Rais, Ichwan Ridwan; Setiawan, Iwan; Pratiwi, Pramita Yuli; Hadibarata, Tony; Tegar, Maulana; Pramono, Suwidjiyo

2014-01-01

Andrographis paniculata (Burm. f.) Nees is a plant that originates from India and grows widely to Southeast which used for several purposes mainly as treatment of diabetes mellitus so the aim of this study was evaluate andrographolide for its pancreatic effect in neonatal streptozotocin (STZ)-induced diabetic rats, a model of type 2 diabetic rats. Diabetic condition was induced with an intraperitoneal injection of 90 mg kg(-1) streptozotocin in two-day-old rats. After three months, the neonatal STZ-induced diabetic rats were treated with andrographolide or andrographolide-enriched extract of A. paniculata (AEEAP) for 8 consecutive days. Pancreatic effect was evaluated by estimating mainly the preprandial and postprandial blood glucose levels and other parameters such as morphology of pancreatic islet, beta cells density and morphology and immunohistochemically pancreatic insulin. Andrographolide significantly (p < 0.05) decreased the levels of blood glucose and improved diabetic rat islet and beta cells. However, AEEAP exhibited moderate hypoglycaemic effects on the blood glucose levels. Moderate changes in beta cells were observed after AEEAP treatment. They could restore decreasing of pancreatic insulin contents. Based on these results andrographolide and AEEAP exhibited pancreatic actions in neonatal STZ-induced diabetic rats. The activity of andrographolide was more effective than this of AEEAP.

Zinc as a paracrine effector in pancreatic islet cell death.

Science.gov (United States)

Kim, B J; Kim, Y H; Kim, S; Kim, J W; Koh, J Y; Oh, S H; Lee, M K; Kim, K W; Lee, M S

2000-03-01

Because of a huge amount of Zn2+ in secretory granules of pancreatic islet beta-cells, Zn2+ released in certain conditions might affect the function or survival of islet cells. We studied potential paracrine effects of endogenous Zn2+ on beta-cell death. Zn2+ induced insulinoma/islet cell death in a dose-dependent manner. Chelation of released endogenous Zn2+ by CaEDTA significantly decreased streptozotocin (STZ)-induced islet cell death in an in vitro culture system simulating in vivo circumstances but not in the conventional culture system. Zn2+ chelation in vivo by continuous CaEDTA infusion significantly decreased the incidence of diabetes after STZ administration. N-(6-methoxy-quinolyl)-para-toluene-sulfonamide staining revealed that Zn2+ was densely deposited in degenerating islet cells 24 h after STZ treatment, which was decreased by CaEDTA infusion. We show here that Zn2+ is not a passive element for insulin storage but an active participant in islet cell death in certain conditions, which in time might contribute to the development of diabetes in aged people.

Extreme Beta-Cell Deficiency in Pancreata of Dogs with Canine Diabetes.

Directory of Open Access Journals (Sweden)

Emily J Shields

Full Text Available The pathophysiology of canine diabetes remains poorly understood, in part due to enigmatic clinical features and the lack of detailed histopathology studies. Canine diabetes, similar to human type 1 diabetes, is frequently associated with diabetic ketoacidosis at onset or after insulin omission. However, notable differences exist. Whereas human type 1 diabetes often occurs in children, canine diabetes is typically described in middle age to elderly dogs. Many competing theories have been proposed regarding the underlying cause of canine diabetes, from pancreatic atrophy to chronic pancreatitis to autoimmune mediated β-cell destruction. It remains unclear to what extent β-cell loss contributes to canine diabetes, as precise quantifications of islet morphometry have not been performed. We used high-throughput microscopy and automated image processing to characterize islet histology in a large collection of pancreata of diabetic dogs. Diabetic pancreata displayed a profound reduction in β-cells and islet endocrine cells. Unlike humans, canine non-diabetic islets are largely comprised of β-cells. Very few β-cells remained in islets of diabetic dogs, even in pancreata from new onset cases. Similarly, total islet endocrine cell number was sharply reduced in diabetic dogs. No compensatory proliferation or lymphocyte infiltration was detected. The majority of pancreata had no evidence of pancreatitis. Thus, canine diabetes is associated with extreme β-cell deficiency in both new and longstanding disease. The β-cell predominant composition of canine islets and the near-total absence of β-cells in new onset elderly diabetic dogs strongly implies that similar to human type 1 diabetes, β-cell loss underlies the pathophysiology of canine diabetes.

Dimethyl sulfoxide inhibits spontaneous diabetes and autoimmune recurrence in non-obese diabetic mice by inducing differentiation of regulatory T cells

International Nuclear Information System (INIS)

Lin, Gu-Jiun; Sytwu, Huey-Kang; Yu, Jyh-Cherng; Chen, Yuan-Wu; Kuo, Yu-Liang; Yu, Chiao-Chi; Chang, Hao-Ming; Chan, De-Chuan; Huang, Shing-Hwa

2015-01-01

Type 1 diabetes mellitus (T1D) is caused by the destruction of insulin-producing β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective therapeutic strategy for T1D. However, the survival of islet grafts can be disrupted by recurrent autoimmunity. Dimethyl sulfoxide (DMSO) is a solvent for organic and inorganic substances and an organ-conserving agent used in solid organ transplantations. DMSO also exerts anti-inflammatory, reactive oxygen species scavenger and immunomodulatory effects and therefore exhibits therapeutic potential for the treatment of several human inflammatory diseases. In this study, we investigated the therapeutic potential of DMSO in the inhibition of autoimmunity. We treated an animal model of islet transplantation (NOD mice) with DMSO. The survival of the syngeneic islet grafts was significantly prolonged. The population numbers of CD8, DC and Th1 cells were decreased, and regulatory T (Treg) cell numbers were increased in recipients. The expression levels of IFN-γ and proliferation of T cells were also reduced following DMSO treatment. Furthermore, the differentiation of Treg cells from naive CD4 T cells was significantly increased in the in vitro study. Our results demonstrate for the first time that in vivo DMSO treatment suppresses spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Treg cells. - Highlights: • We report a therapeutic potential of DMSO in autoimmune diabetes. • DMSO exhibits an immune modulatory effect. • DMSO treatment increases regulatory T cell differentiation. • The increase in STAT5 signaling pathway explains the effect of DMSO in Tregs

Dimethyl sulfoxide inhibits spontaneous diabetes and autoimmune recurrence in non-obese diabetic mice by inducing differentiation of regulatory T cells

Energy Technology Data Exchange (ETDEWEB)

Lin, Gu-Jiun [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Sytwu, Huey-Kang [Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan, ROC (China); Yu, Jyh-Cherng [Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Chen, Yuan-Wu [School of Dentistry, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of Oral and Maxillofacial Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Kuo, Yu-Liang [Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC (China); School of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, ROC (China); Yu, Chiao-Chi [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Chang, Hao-Ming; Chan, De-Chuan [Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China); Huang, Shing-Hwa, E-mail: h610129@gmail.com [Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan, ROC (China); Department of General Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC (China)

2015-01-15

Type 1 diabetes mellitus (T1D) is caused by the destruction of insulin-producing β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective therapeutic strategy for T1D. However, the survival of islet grafts can be disrupted by recurrent autoimmunity. Dimethyl sulfoxide (DMSO) is a solvent for organic and inorganic substances and an organ-conserving agent used in solid organ transplantations. DMSO also exerts anti-inflammatory, reactive oxygen species scavenger and immunomodulatory effects and therefore exhibits therapeutic potential for the treatment of several human inflammatory diseases. In this study, we investigated the therapeutic potential of DMSO in the inhibition of autoimmunity. We treated an animal model of islet transplantation (NOD mice) with DMSO. The survival of the syngeneic islet grafts was significantly prolonged. The population numbers of CD8, DC and Th1 cells were decreased, and regulatory T (Treg) cell numbers were increased in recipients. The expression levels of IFN-γ and proliferation of T cells were also reduced following DMSO treatment. Furthermore, the differentiation of Treg cells from naive CD4 T cells was significantly increased in the in vitro study. Our results demonstrate for the first time that in vivo DMSO treatment suppresses spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Treg cells. - Highlights: • We report a therapeutic potential of DMSO in autoimmune diabetes. • DMSO exhibits an immune modulatory effect. • DMSO treatment increases regulatory T cell differentiation. • The increase in STAT5 signaling pathway explains the effect of DMSO in Tregs.

Effect of long-term transfusion therapy on the glycometabolic status and pancreatic beta cell function in patients with beta Thalassemia major

Directory of Open Access Journals (Sweden)

Kamalakshi G Bhat

2014-01-01

Full Text Available Background: Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major. Design: This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT, and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model was used to calculate the beta cell function and insulin resistance index. Results: Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113. Fasting insulin (P = 0.001, ferritin (P = 0.001, and ALT (P = 0.001 levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001 as also the beta cell function (P = 0.001. With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus. Conclusion: Impaired glucose tolerance (IGT and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

Rising intracellular zinc by membrane depolarization and glucose in insulin-secreting clonal HIT-T15 beta cells.

Science.gov (United States)

Slepchenko, Kira G; Li, Yang V

2012-01-01

Zinc (Zn(2+)) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30-60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

Role of pancreatic polypeptide as a market of transplanted insulin-producing fetal pig cells.

Science.gov (United States)

Tuch, B E; Tabiin, M T; Casamento, F M; Yao, M; Georges, P; Amaratunga, A; Pinto, A N

2001-01-01

Transplantation of insulin-producing fetal pancreatic tissue into diabetic recipients has been shown to normalize blood glucose levels after several months. This time period is required for the growth and maturation of the fetal tissue so insulin levels cannot be used as a marker of graft function while the beta-cell is immature. Therefore, we have examined the use of another pancreatic endocrine hormone, pancreatic polypeptide (PP), to monitor graft function. The cell that produces this hormone has been shown to be the first mature endocrine cell in the fetal pancreas. Fetal pig pancreatic tissue, both in the form of 1 mm3 explants and islet-like cell clusters (ICCs), was transplanted into immunodeficient SCID mice and the levels of PP and insulin were measured in plasma and in the graft for up to 12 weeks. PP was detected in the untransplanted explants (0.58 pmol/mg) and ICCs (0.06 pmol/ICC) and the PP to insulin ratio was 2.7% and 5.8%, respectively. PP (but not porcine C-peptide, a marker of insulin secretion) was detectable in the plasma of SCID mice from 4 days to 3 weeks after transplantation, but not thereafter. The highest values were obtained at 4 days to 1 week. In the grafted tissue PP and insulin were present at all time points and the ratio of PP to insulin was 59%, 87%, 75%, 56%, 7%, 8%, and 7% at 4 days, 1, 2, 3, 6, 9, and 12 weeks, respectively. The decline in PP levels 3 weeks after transplantation was associated with beta-cell development in the graft. PP was also secreted by fetal pig pancreatic explants transplanted into diabetic NOD/SCID mice, with plasma levels measurable in the first week after the tissue was grafted. In immunocompetent BALB/c mice transplanted with the tissue, PP was detectable in plasma for 2 days after transplantation but not at 4 days, when cellular rejection commenced, or thereafter. We conclude that plasma PP levels can be used as a marker of the viability of fetal porcine pancreatic tissue in the first 3 weeks after

Restoration of CFTR Activity in Ducts Rescues Acinar Cell Function and Reduces Inflammation in Pancreatic and Salivary Glands of Mice.

Science.gov (United States)

Zeng, Mei; Szymczak, Mitchell; Ahuja, Malini; Zheng, Changyu; Yin, Hongen; Swaim, William; Chiorini, John A; Bridges, Robert J; Muallem, Shmuel

2017-10-01

Sjögren's syndrome and autoimmune pancreatitis are disorders with decreased function of salivary, lacrimal glands, and the exocrine pancreas. Nonobese diabetic/ShiLTJ mice and mice transduced with the cytokine BMP6 develop Sjögren's syndrome and chronic pancreatitis and MRL/Mp mice are models of autoimmune pancreatitis. Cystic fibrosis transmembrane conductance regulator (CFTR) is a ductal Cl -  channel essential for ductal fluid and HCO 3 - secretion. We used these models to ask the following questions: is CFTR expression altered in these diseases, does correction of CFTR correct gland function, and most notably, does correcting ductal function correct acinar function? We treated the mice models with the CFTR corrector C18 and the potentiator VX770. Glandular, ductal, and acinar cells damage, infiltration, immune cells and function were measured in vivo and in isolated duct/acini. In the disease models, CFTR expression is markedly reduced. The salivary glands and pancreas are inflamed with increased fibrosis and tissue damage. Treatment with VX770 and, in particular, C18 restored salivation, rescued CFTR expression and localization, and nearly eliminated the inflammation and tissue damage. Transgenic overexpression of CFTR exclusively in the duct had similar effects. Most notably, the markedly reduced acinar cell Ca 2+ signaling, Orai1, inositol triphosphate receptors, Aquaporin 5 expression, and fluid secretion were restored by rescuing ductal CFTR. Our findings reveal that correcting ductal function is sufficient to rescue acinar cell function and suggests that CFTR correctors are strong candidates for the treatment of Sjögren's syndrome and pancreatitis. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

An Abbreviated Protocol for In Vitro Generation of Functional Human Embryonic Stem Cell-Derived Beta-Like Cells

DEFF Research Database (Denmark)

Massumi, Mohammad; Pourasgari, Farzaneh; Nalla, Amarnadh

2016-01-01

developed an abbreviated five-stage protocol (25-30 days) to generate human Embryonic Stem Cell-Derived Beta-like Cells (ES-DBCs). We showed that Geltrex, as an extracellular matrix, could support the generation of ES-DBCs more efficiently than that of the previously described culture systems......The ability to yield glucose-responsive pancreatic beta-cells from human pluripotent stem cells in vitro will facilitate the development of the cell replacement therapies for the treatment of Type 1 Diabetes. Here, through the sequential in vitro targeting of selected signaling pathways, we have...... positive cells, 1% insulin and glucagon positive cells and 30% insulin and NKX6.1 co-expressing cells. Functionally, ES-DBCs were responsive to high glucose in static incubation and perifusion studies, and could secrete insulin in response to successive glucose stimulations. Mitochondrial metabolic flux...

Deletion of glutamate dehydrogenase in beta-cells abolishes part of the insulin secretory response not required for glucose homeostasis

DEFF Research Database (Denmark)

Carobbio, Stefania; Frigerio, Francesca; Rubi, Blanca

2009-01-01

Insulin exocytosis is regulated in pancreatic ss-cells by a cascade of intracellular signals translating glucose levels into corresponding secretory responses. The mitochondrial enzyme glutamate dehydrogenase (GDH) is regarded as a major player in this process, although its abrogation has not been...... tested yet in animal models. Here, we generated transgenic mice, named betaGlud1(-/-), with ss-cell-specific GDH deletion. Our results show that GDH plays an essential role in the full development of the insulin secretory response. In situ pancreatic perfusion revealed that glucose-stimulated insulin...... secretion was reduced by 37% in betaGlud1(-/-). Furthermore, isolated islets with either constitutive or acute adenovirus-mediated knock-out of GDH showed a 49 and 38% reduction in glucose-induced insulin release, respectively. Adenovirus-mediated re-expression of GDH in betaGlud1(-/-) islets fully restored...

Immunoglobulin G4 (IgG4)-positive plasma cell infiltration is associated with the clinicopathologic traits and prognosis of pancreatic cancer after curative resection.

Science.gov (United States)

Liu, Qiaofei; Niu, Zheyu; Li, Yuan; Wang, Mengyi; Pan, Boju; Lu, Zhaohui; Liao, Quan; Zhao, Yupei

2016-08-01

Interactions between pancreatic cancer cells and inflammatory cells play crucial roles in the biological behavior of pancreatic cancer. Abundant infiltration of immunoglobulin G4 (IgG4)-positive plasma cells in the pancreas is the most significant feature of autoimmune pancreatitis; however, the clinical significance of IgG4-positive plasma cell infiltration in pancreatic cancer has not previously been reported. Herein, we analyzed intratumoral and peritumoral infiltrations of IgG4-positive plasma cells in 95 pancreatic cancer cases after curative resection. The correlations between IgG4-positive plasma cell infiltration and the clinicopathologic traits and overall survival of pancreatic cancer were investigated. IgG4-positive plasma cells were found in 86 % of tumor tissue samples compared with 69 % of peritumoral tissue samples (P = 0.0063). The high-level infiltration of intratumoral IgG4-positive plasma cells was positively correlated with poor histological grade (P = 0.017). The high-level infiltration of intratumoral IgG4-positive plasma cells was significantly correlated with worse prognosis (P = 0.01) in multivariate analysis. We further found that intratumoral M2-polarized tumor-associated macrophages (TAMs) were positively, linearly correlated with IgG4-positive plasma cells. In conclusion, IgG4-positive plasma cell infiltration is correlated with the clinicopathologic traits and overall survival of pancreatic cancer. High-level intratumoral infiltration of IgG4-positive plasma cells is an independent predictor for poor overall survival in pancreatic cancer patients after curative resection. Intratumoral M2-polarized TAMs probably induce IgG4-positive plasma cells.

Therapeutic Potential of Invariant Natural Killer T Cells in Autoimmunity

Directory of Open Access Journals (Sweden)

Luc Van Kaer

2018-03-01

Full Text Available Tolerance against self-antigens is regulated by a variety of cell types with immunoregulatory properties, such as CD1d-restricted invariant natural killer T (iNKT cells. In many experimental models of autoimmunity, iNKT cells promote self-tolerance and protect against autoimmunity. These findings are supported by studies with patients suffering from autoimmune diseases. Based on these studies, the therapeutic potential of iNKT cells in autoimmunity has been explored. Many of these studies have been performed with the potent iNKT cell agonist KRN7000 or its structural variants. These findings have generated promising results in several autoimmune diseases, although mechanisms by which iNKT cells modulate autoimmunity remain incompletely understood. Here, we will review these preclinical studies and discuss the prospects for translating their findings to patients suffering from autoimmune diseases.

TYK2, a Candidate Gene for Type 1 Diabetes, Modulates Apoptosis and the Innate Immune Response in Human Pancreatic β-Cells

DEFF Research Database (Denmark)

Marroqui, Laura; Dos Santos, Reinaldo Sousa; Fløyel, Tina

2015-01-01

histocompatibility complex (MHC) class I proteins, a hallmark of early β-cell inflammation in type 1 diabetes. Importantly, TYK2 inhibition prevented PIC-induced β-cell apoptosis via the mitochondrial pathway of cell death. The present findings suggest that TYK2 regulates apoptotic and proinflammatory pathways...... in pancreatic β-cells via modulation of IFNα signaling, subsequent increase in MHC class I protein, and modulation of chemokines such as CXCL10 that are important for recruitment of T cells to the islets.......Pancreatic β-cells are destroyed by an autoimmune attack in type 1 diabetes. Linkage and genome-wide association studies point to >50 loci that are associated with the disease in the human genome. Pathway analysis of candidate genes expressed in human islets identified a central role for interferon...

Inflammation increases cells expressing ZSCAN4 and progenitor cell markers in the adult pancreas

Science.gov (United States)

Azuma, Sakiko; Yokoyama, Yukihiro; Yamamoto, Akiko; Kyokane, Kazuhiro; Niida, Shumpei; Ishiguro, Hiroshi; Ko, Minoru S. H.

2013-01-01

We have recently identified the zinc finger and SCAN domain containing 4 (Zscan4), which is transiently expressed and regulates telomere elongation and genome stability in mouse embryonic stem (ES) cells. The aim of this study was to examine the expression of ZSCAN4 in the adult pancreas and elucidate the role of ZSCAN4 in tissue inflammation and subsequent regeneration. The expression of ZSCAN4 and other progenitor or differentiated cell markers in the human pancreas was immunohistochemically examined. Pancreas sections of alcoholic or autoimmune pancreatitis patients before and under maintenance corticosteroid treatment were used in this study. In the adult human pancreas a small number of ZSCAN4-positive (ZSCAN4+) cells are present among cells located in the islets of Langerhans, acini, ducts, and oval-shaped cells. These cells not only express differentiated cell markers for each compartment of the pancreas but also express other tissue stem/progenitor cell markers. Furthermore, the number of ZSCAN4+ cells dramatically increased in patients with chronic pancreatitis, especially in the pancreatic tissues of autoimmune pancreatitis actively regenerating under corticosteroid treatment. Interestingly, a number of ZSCAN4+ cells in the pancreas of autoimmune pancreatitis returned to the basal level after 1 yr of maintenance corticosteroid treatment. In conclusion, coexpression of progenitor cell markers and differentiated cell markers with ZSCAN4 in each compartment of the pancreas may indicate the presence of facultative progenitors for both exocrine and endocrine cells in the adult pancreas. PMID:23599043

T cells to a dominant epitope of GAD65 express a public CDR3 motif.

Science.gov (United States)

Quinn, Anthony; McInerney, Marcia; Huffman, Donald; McInerney, Brigid; Mayo, Stella; Haskins, Kathryn; Sercarz, Eli

2006-06-01

Non-obese diabetic (NOD) mice spontaneously develop autoimmune diabetes, and serve as a model for type 1 diabetes (T1D) and natural autoimmunity. T cell responses to the pancreatic islet antigen glutamic acid decarboxylase 65 (GAD65) can be detected in the spleens of young prediabetic NOD mice, which display a unique MHC class II molecule. Here, we report that a distinct TcR beta chain and CDR3 motif are utilized by all NOD mice in response to a dominant determinant on GAD65, establishing a public repertoire in the spontaneous autoimmunity to an important islet cell antigen. GAD65 530-543 (p530)-reactive T cells preferentially utilize the Vbeta4, Dbeta2.1 and Jbeta2.7 gene segments, with a CDR3 that is characterized by a triad of amino acids, DWG, preceded by a polar residue. In addition, we used CDR3 length spectratyping, CDR3-specific reverse transcriptase-PCR and direct TcR sequencing to show that the TcR beta chain structural patterns associated with p530-specific T cells consistently appeared in the islets of young NOD mice with insulitis, but not in the inflamed islets of streptozotocin-treated C57BL/6 mice, or in inflamed NOD salivary glands. To our knowledge, this is the first report to demonstrate that a public T cell repertoire is used in spontaneous autoimmunity to a dominant self-determinant. These findings suggest that defined clonotypes and repertoires may be preferentially selected in haplotypes predisposed to spontaneous autoimmunity.

The role of polyunsaturated fatty acids (n-3 PUFAs) on the pancreatic β-cells and insulin action.

Science.gov (United States)

Baynes, Habtamu Wondifraw; Mideksa, Seifu; Ambachew, Sintayehu

2018-03-14

Polyunsaturated Fatty acids have multiple effects in peripheral tissues and pancreatic beta cell function. The n-3 Polyunsaturated Fatty acids prevent and reverse high-fat-diet induced adipose tissue inflammation and insulin resistance. Insulin secretion is stimulated by glucose, amino acids, and glucagon- like peptide-1 in tissue containing high levels of n-3 Polyunsaturated Fatty acids than lower level of n-3 Polyunsaturated Fatty acids. Also, n-3 Polyunsaturated Fatty acids led to decreased production of prostaglandin, which in turn contributed to the elevation of insulin secretion. N-3 polyunsaturated fatty acids prevent cytokine-induced cell death in pancreatic islets. Supplementation of n-3 Polyunsaturated Fatty acids for human subjects prevent beta cell destruction and insulin resistance. It also enhances insulin secretion, reduction in lipid profiles and glucose concentration particularly in type II diabetes patients. Therefore there should be a focus on the treatment mechanism of insulin related obesity and diabetes by n-3 polyunsaturated fatty acids.

Chronic pancreatitis.

Science.gov (United States)

Kleeff, Jorg; Whitcomb, David C; Shimosegawa, Tooru; Esposito, Irene; Lerch, Markus M; Gress, Thomas; Mayerle, Julia; Drewes, Asbjørn Mohr; Rebours, Vinciane; Akisik, Fatih; Muñoz, J Enrique Domínguez; Neoptolemos, John P

2017-09-07

Chronic pancreatitis is defined as a pathological fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathological responses to parenchymal injury or stress. Potential causes can include toxic factors (such as alcohol or smoking), metabolic abnormalities, idiopathic mechanisms, genetics, autoimmune responses and obstructive mechanisms. The pathophysiology of chronic pancreatitis is fairly complex and includes acinar cell injury, acinar stress responses, duct dysfunction, persistent or altered inflammation, and/or neuro-immune crosstalk, but these mechanisms are not completely understood. Chronic pancreatitis is characterized by ongoing inflammation of the pancreas that results in progressive loss of the endocrine and exocrine compartment owing to atrophy and/or replacement with fibrotic tissue. Functional consequences include recurrent or constant abdominal pain, diabetes mellitus (endocrine insufficiency) and maldigestion (exocrine insufficiency). Diagnosing early-stage chronic pancreatitis is challenging as changes are subtle, ill-defined and overlap those of other disorders. Later stages are characterized by variable fibrosis and calcification of the pancreatic parenchyma; dilatation, distortion and stricturing of the pancreatic ducts; pseudocysts; intrapancreatic bile duct stricturing; narrowing of the duodenum; and superior mesenteric, portal and/or splenic vein thrombosis. Treatment options comprise medical, radiological, endoscopic and surgical interventions, but evidence-based approaches are limited. This Primer highlights the major progress that has been made in understanding the pathophysiology, presentation, prevalence and management of chronic pancreatitis and its complications.

Pathogenesis of chronic pancreatitis: a comprehensive update and a look into the future.

Science.gov (United States)

Andersson, Roland; Tingstedt, Bobby; Xia, Jinglin

2009-01-01

Chronic pancreatitis is a relatively frequent condition usually caused by alcoholic abuse but also due to recurrent gallstone disease, metabolic endocrine disorders and haemochromatosis, among others. Specific types such as hereditary and autoimmune pancreatitis should be particularly kept in mind and emphasized, as they require specific treatment and attention. The possibility to identify gene mutations has also increased and this is likely to decrease the overall total number of "idiopathic" chronic pancreatitis cases. Pancreatic stellate cells have been identified as potential key players in the progression of chronic pancreatitis and the development of fibrogenesis, which are activated either during repeated attacks of necro-inflammation or directly by toxic factors. The inhibition or modulation of pancreatic stellate cells could represent a way of potential intervention in patients with chronic pancreatitis in the future.

Rac1-NADPH oxidase signaling promotes CD36 activation under glucotoxic conditions in pancreatic beta cells.

Science.gov (United States)

Elumalai, Suma; Karunakaran, Udayakumar; Lee, In Kyu; Moon, Jun Sung; Won, Kyu Chang

2017-04-01

We recently reported that cluster determinant 36 (CD36), a fatty acid transporter, plays a pivotal role in glucotoxicity-induced β-cell dysfunction. However, little is known about how glucotoxicity influences CD36 expression. Emerging evidence suggests that the small GTPase Rac1 is involved in the pathogenesis of beta cell dysfunction in type 2 diabetes (T2D). The primary objective of the current study was to determine the role of Rac1 in CD36 activation and its impact on β-cell dysfunction in diabetes mellitus. To address this question, we subjected INS-1 cells and human beta cells (1.1B4) to high glucose conditions (30mM) in the presence or absence of Rac1 inhibition either by NSC23766 (Rac1 GTPase inhibitor) or small interfering RNA. High glucose exposure in INS-1 and human beta cells (1.1b4) resulted in the activation of Rac1 and induced cell apoptosis. Rac1 activation mediates NADPH oxidase (NOX) activation leading to elevated ROS production in both cells. Activation of the Rac1-NOX complex by high glucose levels enhanced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. The inhibition of Rac1 by NSC23766 inhibited NADPH oxidase activity and ROS generation induced by high glucose concentrations in INS-1 & human 1.1b4 beta cells. Inhibition of Rac1-NOX complex activation by NSC23766 significantly reduced CD36 expression in INS-1 and human 1.1b4 beta cell membrane fractions. In addition, Rac1 inhibition by NSC23766 significantly reduced high glucose-induced mitochondrial dysfunction. Furthermore, NADPH oxidase inhibition by VAS2870 also attenuated high glucose-induced ROS generation and cell apoptosis. These results suggest that Rac1-NADPH oxidase dependent CD36 expression contributes to high glucose-induced beta cell dysfunction and cell death. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Involvement of hypothalamus autoimmunity in patients with autoimmune hypopituitarism: role of antibodies to hypothalamic cells.

Science.gov (United States)

De Bellis, A; Sinisi, A A; Pane, E; Dello Iacovo, A; Bellastella, G; Di Scala, G; Falorni, A; Giavoli, C; Gasco, V; Giordano, R; Ambrosio, M R; Colao, A; Bizzarro, A; Bellastella, A

2012-10-01

Antipituitary antibodies (APA) but not antihypothalamus antibodies (AHA) are usually searched for in autoimmune hypopituitarism. Our objective was to search for AHA and characterize their hypothalamic target in patients with autoimmune hypopituitarism to clarify, on the basis of the cells stained by these antibodies, the occurrence of autoimmune subclinical/clinical central diabetes insipidus (CDI) and/or possible joint hypothalamic contribution to their hypopituitarism. We conducted a cross-sectional cohort study. Ninety-five APA-positive patients with autoimmune hypopituitarism, 60 without (group 1) and 35 with (group 2) lymphocytic hypophysitis, were studied in comparison with 20 patients with postsurgical hypopituitarism and 50 normal subjects. AHA by immunofluorescence and posterior pituitary function were evaluated; then AHA-positive sera were retested by double immunofluorescence to identify the hypothalamic cells targeted by AHA. AHA were detected at high titer in 12 patients in group 1 and in eight patients in group 2. They immunostained arginine vasopressin (AVP)-secreting cells in nine of 12 in group 1 and in four of eight in group 2. All AVP cell antibody-positive patients presented with subclinical/clinical CDI; in contrast, four patients with GH/ACTH deficiency but with APA staining only GH-secreting cells showed AHA targeting CRH- secreting cells. The occurrence of CDI in patients with lymphocytic hypophysitis seems due to an autoimmune hypothalamic involvement rather than an expansion of the pituitary inflammatory process. To search for AVP antibody in these patients may help to identify those of them prone to develop an autoimmune CDI. The detection of AHA targeting CRH-secreting cells in some patients with GH/ACTH deficiency but with APA targeting only GH-secreting cells indicates that an autoimmune aggression to hypothalamus is jointly responsible for their hypopituitarism.

A human beta cell line with drug inducible excision of immortalizing transgenes

Science.gov (United States)

Benazra, Marion; Lecomte, Marie-José; Colace, Claire; Müller, Andreas; Machado, Cécile; Pechberty, Severine; Bricout-Neveu, Emilie; Grenier-Godard, Maud; Solimena, Michele; Scharfmann, Raphaël; Czernichow, Paul; Ravassard, Philippe

2015-01-01

Objectives Access to immortalized human pancreatic beta cell lines that are phenotypically close to genuine adult beta cells, represent a major tool to better understand human beta cell physiology and develop new therapeutics for Diabetes. Here we derived a new conditionally immortalized human beta cell line, EndoC-βH3 in which immortalizing transgene can be efficiently removed by simple addition of tamoxifen. Methods We used lentiviral mediated gene transfer to stably integrate a tamoxifen inducible form of CRE (CRE-ERT2) into the recently developed conditionally immortalized EndoC βH2 line. The resulting EndoC-βH3 line was characterized before and after tamoxifen treatment for cell proliferation, insulin content and insulin secretion. Results We showed that EndoC-βH3 expressing CRE-ERT2 can be massively amplified in culture. We established an optimized tamoxifen treatment to efficiently excise the immortalizing transgenes resulting in proliferation arrest. In addition, insulin expression raised by 12 fold and insulin content increased by 23 fold reaching 2 μg of insulin per million cells. Such massive increase was accompanied by enhanced insulin secretion upon glucose stimulation. We further observed that tamoxifen treated cells maintained a stable function for 5 weeks in culture. Conclusions EndoC βH3 cell line represents a powerful tool that allows, using a simple and efficient procedure, the massive production of functional non-proliferative human beta cells. Such cells are close to genuine human beta cells and maintain a stable phenotype for 5 weeks in culture. PMID:26909308

LGR5 and Nanog identify stem cell signature of pancreas beta cells which initiate pancreatic cancer.

Science.gov (United States)

Amsterdam, Abraham; Raanan, Calanit; Schreiber, Letizia; Polin, Nava; Givol, David

2013-04-05

Pancreas cancer, is the fourth leading cause of cancer death but its cell of origin is controversial. We compared the localization of stem cells in normal and cancerous pancreas using antibodies to the stem cell markers Nanog and LGR5. Here we show, for the first time, that LGR5 is expressed in normal pancreas, exclusively in the islets of Langerhans and it is co-localized, surprisingly, with Nanog and insulin in clusters of beta cells. In cancerous pancreas Nanog and LGR5 are expressed in the remaining islets and in all ductal cancer cells. We observed insulin staining among the ductal cancer cells, but not in metastases. This indicates that the islet's beta cells, expressing LGR5 and Nanog markers are the initiating cells of pancreas cancer, which migrated from the islets to form the ductal cancerous tissue, probably after mutation and de-differentiation. This discovery may facilitate treatment of this devastating cancer. Copyright © 2013 Elsevier Inc. All rights reserved.

Intermittent fasting preserves beta-cell mass in obesity-induced diabetes via the autophagy-lysosome pathway.

Science.gov (United States)

Liu, Haiyan; Javaheri, Ali; Godar, Rebecca J; Murphy, John; Ma, Xiucui; Rohatgi, Nidhi; Mahadevan, Jana; Hyrc, Krzysztof; Saftig, Paul; Marshall, Connie; McDaniel, Michael L; Remedi, Maria S; Razani, Babak; Urano, Fumihiko; Diwan, Abhinav

2017-01-01

Obesity-induced diabetes is characterized by hyperglycemia, insulin resistance, and progressive beta cell failure. In islets of mice with obesity-induced diabetes, we observe increased beta cell death and impaired autophagic flux. We hypothesized that intermittent fasting, a clinically sustainable therapeutic strategy, stimulates autophagic flux to ameliorate obesity-induced diabetes. Our data show that despite continued high-fat intake, intermittent fasting restores autophagic flux in islets and improves glucose tolerance by enhancing glucose-stimulated insulin secretion, beta cell survival, and nuclear expression of NEUROG3, a marker of pancreatic regeneration. In contrast, intermittent fasting does not rescue beta-cell death or induce NEUROG3 expression in obese mice with lysosomal dysfunction secondary to deficiency of the lysosomal membrane protein, LAMP2 or haplo-insufficiency of BECN1/Beclin 1, a protein critical for autophagosome formation. Moreover, intermittent fasting is sufficient to provoke beta cell death in nonobese lamp2 null mice, attesting to a critical role for lysosome function in beta cell homeostasis under fasting conditions. Beta cells in intermittently-fasted LAMP2- or BECN1-deficient mice exhibit markers of autophagic failure with accumulation of damaged mitochondria and upregulation of oxidative stress. Thus, intermittent fasting preserves organelle quality via the autophagy-lysosome pathway to enhance beta cell survival and stimulates markers of regeneration in obesity-induced diabetes.

Developmental programming of polycystic ovary syndrome (PCOS): prenatal androgens establish pancreatic islet α/β cell ratio and subsequent insulin secretion.

Science.gov (United States)

Ramaswamy, S; Grace, C; Mattei, A A; Siemienowicz, K; Brownlee, W; MacCallum, J; McNeilly, A S; Duncan, W C; Rae, M T

2016-06-06

Exogenous androgenic steroids applied to pregnant sheep programmes a PCOS-like phenotype in female offspring. Via ultrasound guidance we applied steroids directly to ovine fetuses at d62 and d82 of gestation, and examined fetal (day 90 gestation) and postnatal (11 months old) pancreatic structure and function. Of three classes of steroid agonists applied (androgen - Testosterone propionate (TP), estrogen - Diethystilbesterol (DES) and glucocorticoid - Dexamethasone (DEX)), only androgens (TP) caused altered pancreatic development. Beta cell numbers were significantly elevated in prenatally androgenised female fetuses (P = 0.03) (to approximately the higher numbers found in male fetuses), whereas alpha cell counts were unaffected, precipitating decreased alpha:beta cell ratios in the developing fetal pancreas (P = 0.001), sustained into adolescence (P = 0.0004). In adolescence basal insulin secretion was significantly higher in female offspring from androgen-excess pregnancies (P = 0.045), and an exaggerated, hyperinsulinaemic response to glucose challenge (P = 0.0007) observed, whereas prenatal DES or DEX treatment had no effects upon insulin secretion. Postnatal insulin secretion correlated with beta cell numbers (P = 0.03). We conclude that the pancreas is a primary locus of androgenic stimulation during development, giving rise to postnatal offspring whose pancreas secreted excess insulin due to excess beta cells in the presence of a normal number of alpha cells.

Lysine deacetylases are produced in pancreatic beta cells and are differentially regulated by proinflammatory cytokines

DEFF Research Database (Denmark)

Lundh, M; Christensen, D P; Rasmussen, D N

2010-01-01

Cytokine-induced beta cell toxicity is abrogated by non-selective inhibitors of lysine deacetylases (KDACs). The KDAC family consists of 11 members, namely histone deacetylases HDAC1 to HDAC11, but it is not known which KDAC members play a role in cytokine-mediated beta cell death. The aim...

Simultaneous characterization of pancreatic stellate cells and other pancreatic components within three-dimensional tissue environment during chronic pancreatitis

Science.gov (United States)

Hu, Wenyan; Fu, Ling

2013-05-01

Pancreatic stellate cells (PSCs) and other pancreatic components that play a critical role in exocrine pancreatic diseases are generally identified separately by conventional studies, which provide indirect links between these components. Here, nonlinear optical microscopy was evaluated for simultaneous characterization of these components within a three-dimensional (3-D) tissue environment, primarily based on multichannel detection of intrinsic optical emissions and cell morphology. Fresh rat pancreatic tissues harvested at 1 day, 7 days, and 28 days after induction of chronic pancreatitis were imaged, respectively. PSCs, inflammatory cells, blood vessels, and collagen fibers were identified simultaneously. The PSCs at day 1 of chronic pancreatitis showed significant enlargement compared with those in normal pancreas (ppancreatic components coincidently within 3-D pancreatic tissues. It is a prospect for intravital observation of dynamic events under natural physiological conditions, and might help uncover the key mechanisms of exocrine pancreatic diseases, leading to more effective treatments.

Pancreatic Islet Cell Transplantation

Science.gov (United States)

Warnock, Garth L.; Rajotte, Ray V.

1992-01-01

Transplantation of insulin-producing tissue offers a physiologic approach to restoration of glycemic control. Whereas transplantation of vascularized pancreatic grafts has recently achieved encouraging results, pancreatic islet cell transplantation holds the promise of low morbidity and reduced requirements for agressive immunosuppression for recipients. Islet cell transplantation was recently demonstrated to induce euglycemia with insulin independence. Imagesp1656-a PMID:21221366

Rising Intracellular Zinc by Membrane Depolarization and Glucose in Insulin-Secreting Clonal HIT-T15 Beta Cells

Directory of Open Access Journals (Sweden)

Kira G. Slepchenko

2012-01-01

Full Text Available Zinc (Zn2+ appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30–60 mM was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

Palmitate activates autophagy in INS-1E β-cells and in isolated rat and human pancreatic islets.

Directory of Open Access Journals (Sweden)

Luisa Martino

Full Text Available We have investigated the in vitro effects of increased levels of glucose and free fatty acids on autophagy activation in pancreatic beta cells. INS-1E cells and isolated rat and human pancreatic islets were incubated for various times (from 2 to 24 h at different concentrations of glucose and/or palmitic acid. Then, cell survival was evaluated and autophagy activation was explored by using various biochemical and morphological techniques. In INS-1E cells as well as in rat and human islets, 0.5 and 1.0 mM palmitate markedly increased autophagic vacuole formation, whereas high glucose was ineffective alone and caused little additional change when combined with palmitate. Furthermore, LC3-II immunofluorescence co-localized with that of cathepsin D, a lysosomal marker, showing that the autophagic flux was not hampered in PA-treated cells. These effects were maintained up to 18-24 h incubation and were associated with a significant decline of cell survival correlated with both palmitate concentration and incubation time. Ultrastructural analysis showed that autophagy activation, as evidenced by the occurrence of many autophagic vacuoles in the cytoplasm of beta cells, was associated with a diffuse and remarkable swelling of the endoplasmic reticulum. Our results indicate that among the metabolic alterations typically associated with type 2 diabetes, high free fatty acids levels could play a role in the activation of autophagy in beta cells, through a mechanism that might involve the induction of endoplasmic reticulum stress.

Stabilization of beta-catenin induces pancreas tumor formation.

Science.gov (United States)

Heiser, Patrick W; Cano, David A; Landsman, Limor; Kim, Grace E; Kench, James G; Klimstra, David S; Taketo, Maketo M; Biankin, Andrew V; Hebrok, Matthias

2008-10-01

beta-Catenin signaling within the canonical Wnt pathway is essential for pancreas development. However, the pathway is normally down-regulated in the adult organ. Increased cytoplasmic and nuclear localization of beta-catenin can be detected in nearly all human solid pseudopapillary neoplasms (SPN), a rare tumor with low malignant potential. Conversely, pancreatic ductal adenocarcinoma (PDA) accounts for the majority of pancreatic tumors and is among the leading causes of cancer death. Whereas activating mutations within beta-catenin and other members of the canonical Wnt pathway are rare, recent reports have implicated Wnt signaling in the development and progression of human PDA. Here, we sought to address the role of beta-catenin signaling in pancreas tumorigenesis. Using Cre/lox technology, we conditionally activated beta-catenin in a subset of murine pancreatic cells in vivo. Activation of beta-catenin results in the formation of large pancreatic tumors at a high frequency in adult mice. These tumors resemble human SPN based on morphologic and immunohistochemical comparisons. Interestingly, stabilization of beta-catenin blocks the formation of pancreatic intraepithelial neoplasia (PanIN) in the presence of an activating mutation in Kras that is known to predispose individuals to PDA. Instead, mice in which beta-catenin and Kras are concurrently activated develop distinct ductal neoplasms that do not resemble PanIN lesions. These results demonstrate that activation of beta-catenin is sufficient to induce pancreas tumorigenesis. Moreover, they indicate that the sequence in which oncogenic mutations are acquired has profound consequences on the phenotype of the resulting tumor.

Imaging dynamics of CD11c+ cells and Foxp3+ cells in progressive autoimmune insulitis in the NOD mouse model of type 1 diabetes

DEFF Research Database (Denmark)

Schmidt-Christensen, Anja; Hansen, Lisbeth; Ilegems, Erwin

2013-01-01

the endocrine pancreas during initiation and progression of insulitis in the NOD mouse. Individual, ACE-transplanted islets of Langerhans were longitudinally and repetitively imaged by stereomicroscopy and two-photon microscopy to follow fluorescently labelled leucocyte subsets. Results We demonstrate that......, in spite of the immune privileged status of the eye, the ACE-transplanted islets develop infiltration and beta cell destruction, recapitulating the autoimmune insulitis of the pancreas, and exemplify this by analysing reporter cell populations expressing green fluorescent protein under the Cd11c or Foxp3......Aims/hypothesis The aim of this study was to visualise the dynamics and interactions of the cells involved in autoimmune-driven inflammation in type 1 diabetes. Methods We adopted the anterior chamber of the eye (ACE) transplantation model to perform non-invasive imaging of leucocytes infiltrating...

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

International Nuclear Information System (INIS)

Ji, S.Q.; Cao, J.; Zhang, Q.Y.; Li, Y.Y.; Yan, Y.Q.; Yu, F.X.

2013-01-01

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

Energy Technology Data Exchange (ETDEWEB)

Ji, S.Q.; Cao, J. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Zhang, Q.Y.; Li, Y.Y. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China); Yan, Y.Q. [Department of Liver Surgery I, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai (China); Yu, F.X. [Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital, Wenzhou Medical College, Wenzhou (China)

2013-09-27

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitro and the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis.

Pancreatic Cancer-Derived Exosomes Cause Paraneoplastic β-cell Dysfunction.

Science.gov (United States)

Javeed, Naureen; Sagar, Gunisha; Dutta, Shamit K; Smyrk, Thomas C; Lau, Julie S; Bhattacharya, Santanu; Truty, Mark; Petersen, Gloria M; Kaufman, Randal J; Chari, Suresh T; Mukhopadhyay, Debabrata

2015-04-01

Pancreatic cancer frequently causes diabetes. We recently proposed adrenomedullin as a candidate mediator of pancreatic β-cell dysfunction in pancreatic cancer. How pancreatic cancer-derived adrenomedullin reaches β cells remote from the cancer to induce β-cell dysfunction is unknown. We tested a novel hypothesis that pancreatic cancer sheds adrenomedullin-containing exosomes into circulation, which are transported to β cells and impair insulin secretion. We characterized exosomes from conditioned media of pancreatic cancer cell lines (n = 5) and portal/peripheral venous blood of patients with pancreatic cancer (n = 20). Western blot analysis showed the presence of adrenomedullin in pancreatic cancer-exosomes. We determined the effect of adrenomedullin-containing pancreatic cancer exosomes on insulin secretion from INS-1 β cells and human islets, and demonstrated the mechanism of exosome internalization into β cells. We studied the interaction between β-cell adrenomedullin receptors and adrenomedullin present in pancreatic cancer-exosomes. In addition, the effect of adrenomedullin on endoplasmic reticulum (ER) stress response genes and reactive oxygen/nitrogen species generation in β cells was shown. Exosomes were found to be the predominant extracellular vesicles secreted by pancreatic cancer into culture media and patient plasma. Pancreatic cancer-exosomes contained adrenomedullin and CA19-9, readily entered β cells through caveolin-mediated endocytosis or macropinocytosis, and inhibited insulin secretion. Adrenomedullin in pancreatic cancer exosomes interacted with its receptor on β cells. Adrenomedullin receptor blockade abrogated the inhibitory effect of exosomes on insulin secretion. β cells exposed to adrenomedullin or pancreatic cancer exosomes showed upregulation of ER stress genes and increased reactive oxygen/nitrogen species. Pancreatic cancer causes paraneoplastic β-cell dysfunction by shedding adrenomedullin(+)/CA19-9(+) exosomes into

Regulatory dendritic cells in autoimmunity: A comprehensive review.

Science.gov (United States)

Liu, Juan; Cao, Xuetao

2015-09-01

Dendritic cells (DCs) are professional antigen-presenting cells (APC) with significant phenotypic heterogeneity and functional plasticity. DCs play crucial roles in initiating effective adaptive immune responses for elimination of invading pathogens and also in inducing immune tolerance toward harmless components to maintain immune homeostasis. The regulatory capacity of DCs depends on their immature state and distinct subsets, yet not restricted to the immature state and one specialized subset. The tolerogenicity of DC is controlled by a complex network of environmental signals and cellular intrinsic mechanisms. Regulatory DCs play an important role in the maintenance of immunological tolerance via the induction of T cell unresponsiveness or apoptosis, and generation of regulatory T cells. DCs play essential roles in driving autoimmunity via promoting the activation of effector T cells such as T helper 1 and T helper 17 cells, and/or suppressing the generation of regulatory T cells. Besides, a breakdown of DCs-mediated tolerance due to abnormal environmental signals or breakdown of intrinsic regulatory mechanisms is closely linked with the pathogenesis of autoimmune diseases. Novel immunotherapy taking advantage of the tolerogenic potential of regulatory DCs is being developed for treatment of autoimmune diseases. In this review, we will describe the current understanding on the generation of regulatory DC and the role of regulatory DCs in promoting tolerogenic immune responses and suppressing autoimmune responses. The emerging roles of DCs dysfunction in the pathogenesis of autoimmune diseases and the potential application of regulatory DCs in the treatment of autoimmune diseases will also be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of fetal and neonatal environment on beta cell function and development of diabetes

DEFF Research Database (Denmark)

Nielsen, Jens H; Haase, Tobias N; Jaksch, Caroline

2014-01-01

on the beta cells in both the mother and the fetus and how various conditions like diabetes, obesity, overnutrition and undernutrition during and after pregnancy may influence the ability of the offspring to adapt to changes in insulin demand later in life. The influence of environmental factors including...... that the intrauterine environment during pregnancy has an impact on the gene expression that may persist until adulthood and cause metabolic diseases like obesity and type 2 diabetes. As the pancreatic beta cells are crucial in the regulation of metabolism this article will describe the influence of normal pregnancy...... nutrients and gut microbiota on appetite regulation, mitochondrial activity and the immune system that may affect beta cell growth and function directly and indirectly is discussed. The possible role of epigenetic changes in the transgenerational transmission of the adverse programming may be the most...

Elevation of serum IgG4 in Western patients with autoimmune sclerosing pancreatocholangitis: a word of caution.

Science.gov (United States)

Hochwald, Steven N; Hemming, Alan W; Draganov, Peter; Vogel, Stephen B; Dixon, Lisa R; Grobmyer, Stephen R

2008-04-01

Autoimmune pancreatocholangitis is characterized by sclerosing inflammation of the biliary tree or pancreatic duct and can mimic pancreaticobiliary malignancy. Serum immunoglobin (Ig) G4 values seem to be helpful in distinguishing autoimmune pancreatocholangitis from pancreatic malignancy in the Japanese population; however, its significance in the Western population has not been well studied. We report a retrospective analysis of 7 consecutive patients with autoimmune pancreatocholangitis and compare them to 23 patients with pancreatic malignancy. Clinical presentation, diagnostic tests, and preoperative IgG4 levels were reviewed in all patients. Presence of autoimmune pancreatocholangitis or pancreatic malignancy was determined by pathologic analysis in all patients and reviewed by a single pathologist. In all patients, autoimmune pancreatocholangitis manifested in a similar fashion to pancreatic malignancy. Median IgG4 levels were far lower in pancreatic cancer patients with localized, resectable disease (24 mg/dL), locally advanced disease (24 mg/dL), and metastatic disease (28 mg/dL) as compared with patients with autoimmune pancreatocholangitis (142 mg/dL, P 100 mg/dL. In contrast, all patients with autoimmune pancreatitis or cholangitis had levels >100 mg/dL. However, in five of these seven patients, IgG4 levels were below the upper limits of normal. Autoimmune pancreatocholangitis mimics pancreatobiliary malignancy. Serum IgG4 values seem to be helpful in distinguishing autoimmune pancreatocholangitis from malignancy in the Western population. However, absolute values seem to be lower in the United States compared with Japan. The upper limit of normal as reported in laboratories in the United States may not be useful in identifying abnormally high IgG4 values. A new upper limit of normal may need to be defined because IgG subclass determinations are being used more frequently in Western patients with biliary obstruction.

Curcumin Modulates Pancreatic Adenocarcinoma Cell-Derived Exosomal Function

Science.gov (United States)

Osterman, Carlos J. Diaz; Lynch, James C.; Leaf, Patrick; Gonda, Amber; Ferguson Bennit, Heather R.; Griffiths, Duncan; Wall, Nathan R.

2015-01-01

Pancreatic cancer has the highest mortality rates of all cancer types. One potential explanation for the aggressiveness of this disease is that cancer cells have been found to communicate with one another using membrane-bound vesicles known as exosomes. These exosomes carry pro-survival molecules and increase the proliferation, survival, and metastatic potential of recipient cells, suggesting that tumor-derived exosomes are powerful drivers of tumor progression. Thus, to successfully address and eradicate pancreatic cancer, it is imperative to develop therapeutic strategies that neutralize cancer cells and exosomes simultaneously. Curcumin, a turmeric root derivative, has been shown to have potent anti-cancer and anti-inflammatory effects in vitro and in vivo. Recent studies have suggested that exosomal curcumin exerts anti-inflammatory properties on recipient cells. However, curcumin’s effects on exosomal pro-tumor function have yet to be determined. We hypothesize that curcumin will alter the pro-survival role of exosomes from pancreatic cancer cells toward a pro-death role, resulting in reduced cell viability of recipient pancreatic cancer cells. The main objective of this study was to determine the functional alterations of exosomes released by pancreatic cancer cells exposed to curcumin compared to exosomes from untreated pancreatic cancer cells. We demonstrate, using an in vitro cell culture model involving pancreatic adenocarcinoma cell lines PANC-1 and MIA PaCa-2, that curcumin is incorporated into exosomes isolated from curcumin-treated pancreatic cancer cells as observed by spectral studies and fluorescence microscopy. Furthermore, curcumin is delivered to recipient pancreatic cancer cells via exosomes, promoting cytotoxicity as demonstrated by Hoffman modulation contrast microscopy as well as AlamarBlue and Trypan blue exclusion assays. Collectively, these data suggest that the efficacy of curcumin may be enhanced in pancreatic cancer cells through

Urtica Dioica Distillate Regenerates Pancreatic Beta Cells in Streptozotocin-Induced Diabetic Rats

Science.gov (United States)

Gohari, Ali; Noorafshan, Ali; Akmali, Masoumeh; Zamani-Garmsiri, Fahimeh; Seghatoleslam, Atefeh

2018-01-01

Background Urtica dioica is known as an anti-hyperglycemic plant. Urtica dioica distillate (UD) is a traditional Iranian drink, locally known as “aragh gazaneh”. In spite of its widespread consumption in Iran, according to traditional Iranian medicine, there is no scientific report on the usefulness of UD for diabetic patients. This survey was designed to evaluate its protective effects for the recovery from diabetes by determining the serum insulin, blood glucose, volume of pancreatic islets, and the number and volume of β-cells in diabetic rats. Methods A total of 48 Sprague-Dawley male rats (200-250 g) were randomly distributed into 6 groups (n=8), including non-diabetic plus distilled water (DW), non-diabetic plus UD, diabetic plus DW, diabetic plus UD, diabetic plus insulin, and diabetic plus glibenclamide. DW, UD, and glibenclamide were administered via intragastric gavage and insulin was injected subcutaneously. After four weeks of experiments, blood samples were collected for serum insulin and blood glucose assay. Pancreas was also evaluated using stereological method. The SPSS software was used for statistical analysis. Kruskal-Wallis, repeated measurements, and Mann-Whitney U test were applied for comparisons between the groups. Results The treatment of diabetic rats with UD reduced the blood glucose dramatically (P<0.001) and increased serum insulin levels significantly (P=0.03) in comparison to the diabetic plus DW rats. Treatment with UD did not affect the mean β-cell volumes in the diabetic rats when compared to the diabetic plus DW rats, but the islet volumes and β-cell numbers were significantly recovered. Conclusion UD treatment in diabetic rats improves hyperglycemia by partially restoring plasma insulin levels. The data suggest that UD prevents islet atrophy and/or regenerate pancreatic β-cells. PMID:29749986

Double negative (CD3+ 4- 8- TCR alphabeta splenic cells from young NOD mice provide long-lasting protection against type 1 diabetes.

Directory of Open Access Journals (Sweden)

Beverly Duncan

2010-07-01

Full Text Available Double negative CD3(+4(-8(- TCR alphabeta splenic cells (DNCD3 can suppress the immune responses to allo and xenografts, infectious agents, tumors, and some autoimmune disorders. However, little is known about their role in autoimmune diabetes, a disease characterized by the reduction of insulin production subsequent to destruction of pancreatic beta-cells by a polyclonal population of self-reactive T-cells. Herein, we analyzed the function and phenotype of DNCD3 splenic cells in young NOD mice predisposed to several autoimmune disorders among which, the human-like autoimmune diabetes.DNCD3 splenic cells from young NOD mice (1 provided long-lasting protection against diabetes transfer in NOD/Scid immunodeficient mice, (2 proliferated and differentiated in the spleen and pancreas of NOD/Scid mice and pre-diabetic NOD mice into IL-10-secreting T(R-1 like cells in a Th2-like environment, and (3 their anti-diabetogenic phenotype is CD3(+(CD4(-CD8(-CD28(+CD69(+CD25(low Foxp3(- iCTLA-4(-TCR alphabeta(+ with a predominant Vbeta13 gene usage.These findings delineate a new T regulatory component in autoimmune diabetes apart from that of NKT and CD4(+CD25(high Foxp3(+T-regulatory cells. DNCD3 splenic cells could be potentially manipulated towards the development of autologous cell therapies in autoimmune diabetes.