UPR induces transient burst of apoptosis in islets of early lactating rats through reduced AKT phosphorylation via ATF4/CHOP stimulation of TRB3 expression

Bromati CR, Lellis-Santos C, Yamanaka TS, Nogueira TC, Leonelli M, Caperuto LC, Gorjao R, Leite AR, Anhe GF, Bordin S. UPR induces transient burst of apoptosis in islets of early lactating rats through reduced AKT phosphorylation via ATF4/CHOP stimulation of TRB3 expression. Am J Physiol Regul Integr Comp Physiol 300: R92-R100, 2011. First published November 10, 2010; doi:10.1152/ajpregu.00169.2010.-Endocrine pancreas from pregnant rats undergoes several adaptations that comprise increase in beta-cell number, mass and insulin secretion, and reduction of apoptosis. Lactogens are the main hormones that account for these changes. Maternal pancreas, however, returns to a nonpregnant state just after the delivery. The precise mechanism by which this reversal occurs is not settled but, in spite of high lactogen levels, a transient increase in apoptosis was already reported as early as the 3rd day of lactation (L3). Our results revealed that maternal islets displayed a transient increase in DNA fragmentation at L3, in parallel with decreased RAC-alpha serine/threonine-protein kinase (AKT) phosphorylation (pAKT), a known prosurvival kinase. Wortmannin completely abolished the prosurvival action of prolactin (PRL) in cultured islets. Decreased pAKT in L3-islets correlated with increased Tribble 3 (TRB3) expression, a pseudokinase inhibitor of AKT. PERK and eIF2 alpha phosphorylation transiently increased in islets from rats at the first day after delivery, followed by an increase in immunoglobulin heavy chain-binding protein (BiP), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) in islets from L3 rats. Chromatin immunoprecipitation (ChIP) and Re-ChIP experiments further confirmed increased binding of the heterodimer ATF4/CHOP to the TRB3 promoter in L3 islets. Treatment with PBA, a chemical chaperone that inhibits UPR, restored pAKT levels and inhibited the increase in apoptosis found in L3. Moreover, PBA reduced CHOP and TRB3 levels in beta-cell from L3 rats. Altogether, our study collects compelling evidence that UPR underlies the physiological and transient increase in beta-cell apoptosis after delivery. The UPR is likely to counteract prosurvival actions of PRL by reducing pAKT through ATF4/CHOP-induced TRB3 expression.

Augmentation of insulin secretion by leucine supplementation in malnourished rats: possible involvement of the phosphatidylinositol 3-phosphate kinase/mammalian target protein of rapamycin pathway

A regimen of low-protein diet induces a reduction of pancreatic islet function that is associated with development of metabolic disorders including diabetes and obesity afterward. In the present study, the influence of leucine supplementation on metabolic parameters, insulin secretion to glucose and to amino acids, as well as the levels of proteins that participate in the phosphatidylinositol 3-phosphate kinase (PI3K) pathway was investigated in malnourished rats. Four groups were fed with different diets for 12 weeks: a normal protein diet (17%) without (NP) or with leucine supplementation (NPL) or a low (6%)-protein diet without (LP) or with leucine supplementation (LPL). Leucine was given in the drinking water during the last 4 weeks. As indicated by the intraperitoneal glucose tolerance test, LPL rats exhibited increased glucose tolerance as compared with NPL group. Both NPL and LPL rats had higher circulating insulin levels than controls. The LPL rats also showed increased insulin secretion by pancreatic islets in response to glucose or arginine compared with those observed in islets from LP animals. Glucose oxidation was significantly reduced in NPL, LP, and LPL isolated islets as compared with NP; but no alteration was observed for leucine and glutamate oxidation among the 4 groups. Western blotting analysis demonstrated increased PI3K and mammalian target protein of rapamycin protein contents in LPL compared with LP islets. A significant increase in insulin-induced insulin receptor substrate I associated PI3K activation was also observed in LPL compared with LP islets. These findings indicate that leucine supplementation can augment islet function in malnourished rats and that activation of the PI3K/maminalian target protein of rapamycin pathway may play a role in this process. (C) 2010 Elsevier Inc. All rights reserved.

Antibody-mediated rejection (AMR) after pancreas and pancreas-kidney transplantation

P>Antibody-mediated rejection (AMR) requires specific diagnostic tools and treatment and is associated with lower graft survival. We prospectively screened C4d in pancreas (n = 35, in 27 patients) and kidney (n = 33, in 21 patients) for cause biopsies. Serum amylase and lipase, amylasuria, fasting blood glucose (FBG) and 2-h capillary glucose (CG) were also analysed. We found that 27.3% of kidney biopsies and 43% of pancreatic biopsies showed C4d staining (66.7% and 53.3% diffuse in peritubular and interacinar capillaries respectively). Isolated exocrine dysfunction was the main indication for pancreas biopsy (54.3%) and was followed by both exocrine and endocrine dysfunctions (37.1%) and isolated endocrine dysfunction (8.6%). Laboratorial parameters were comparable between T-cell mediated rejection and AMR: amylase 151.5 vs. 149 U/l (P = 0.075), lipase 1120 vs. 1288.5 U/l (P = 0.83), amylasuria variation 46.5 vs. 61% (P = 0.97), FBG 69 vs. 97 mg/dl (P = 0.20) and 2-h CG maximum 149.5 vs. 197.5 mg/dl (P = 0.49) respectively. Amylasuria values after treatment correlated with pancreas allograft loss (P = 0.015). These data suggest that C4d staining should be routinely investigated when pancreas allograft dysfunction is present because of its high detection rate in cases of rejection.

Acinar cell carcinoma of the pancreas: is the absence of neuroendocrine component related to a more malignant behavior?

Background/Aims: Acinar cell carcinomas are uncommon malignant tumors of the pancreas, accounting for 1-2% of all the cases of exocrine pancreatic tumor. Some authors have estimated acinar cell tumors to be as aggressive as ductal adenocarcinoma of the pancreas whereas other series showed acinar cell tumors to have a favorable clinical outcome. This discrepancy in prognosis may be related to the cellular components of the tumor. Methodology: With the aim to evaluate the possible relationship between the presence of neuroendocrine differentiation and behavior of these tumors, the authors reviewed all patients presenting acinar cell carcinoma of the pancreas in the last 5 years with emphasis in the immunohistochemical evaluation. Results: Four patients presented neuroendocrine differentiation on immunohistochemical evaluation and had a more benign outcome. Two patients without neuroendocrine component had a disseminated disease at presentation. This data suggests that this tumor is less aggressive than ductal adenocarcinoma and even with nodal involvement, long term survival after complete resection can be achieved. Conclusions: It is possible that the absence of neuroendocrine component may be related to a less favorable outcome and adjuvant therapy may be necessary. Due to the rarity of this pancreatic tumor, this relationship remains to be confirmed with a multicentric study including a larger number of patients.

Localization of myosin-Va in subpopulations of cells in rat endocrine organs

Myosin-Va is a Ca2+/calmodulin-regulated unconventional myosin involved in the transport of vesicles, membranous organelles, and macromolecular complexes composed of proteins and mRNA. The cellular localization of myosin-Va has been described in great detail in several vertebrate cell types, including neurons, melanocytes, lymphocytes, auditory tissues, and a number of cultured cells. Here, we provide an immunohistochemical view of the tissue distribution of myosin-Va in the major endocrine organs. Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells. Weak to moderate staining has been detected in steroidogenic cells of the adrenal cortex, ovary, and Leydig cells. Myosin-Va has also been localized to non-endocrine cells, such as the germ cells of the seminiferous epithelium and maturing oocytes and in the intercalated ducts of the exocrine pancreas. These data provide the first systematic description of myosin-Va localization in the major endocrine organs of rat.

Endothelial dysfunction in cardiovascular and endocrine-metabolic diseases: an update

The endothelium plays a vital role in maintaining circulatory homeostasis by the release of relaxing and contracting factors. Any change in this balance may result in a process known as endothelial dysfunction that leads to impaired control of vascular tone and contributes to the pathogenesis of some cardiovascular and endocrine/metabolic diseases. Reduced endothelium-derived nitric oxide (NO) bioavailability and increased production of thromboxane A2, prostaglandin H2 and superoxide anion in conductance and resistance arteries are commonly associated with endothelial dysfunction in hypertensive, diabetic and obese animals, resulting in reduced endothelium-dependent vasodilatation and in increased vasoconstrictor responses. In addition, recent studies have demonstrated the role of enhanced overactivation ofβ-adrenergic receptors inducing vascular cytokine production and endothelial NO synthase (eNOS) uncoupling that seem to be the mechanisms underlying endothelial dysfunction in hypertension, heart failure and in endocrine-metabolic disorders. However, some adaptive mechanisms can occur in the initial stages of hypertension, such as increased NO production by eNOS. The present review focuses on the role of NO bioavailability, eNOS uncoupling, cyclooxygenase-derived products and pro-inflammatory factors on the endothelial dysfunction that occurs in hypertension, sympathetic hyperactivity, diabetes mellitus, and obesity. These are cardiovascular and endocrine-metabolic diseases of high incidence and mortality around the world, especially in developing countries and endothelial dysfunction contributes to triggering, maintenance and worsening of these pathological situations.

Development, implementation, and assessment of a distance module in endocrine physiology

Rangel EM, Mendes IA, Carnio EC, Marchi Alves LM, Godoy S, Crispim JA. Development, implementation, and assessment of a distance module in endocrine physiology. Adv Physiol Educ 34: 70-74, 2010; doi: 10.1152/advan.00070.2009.-This study aimed to develop, implement, and assess a distance module in endocrine physiology in TelEduc for undergraduate nursing students from a public university in Brazil, with a sample size of 44 students. Stage 1 consisted of the development of the module, through the process of creating a distance course by means of the Web. Stage 2 was the planning of the module's practical functioning, and stage 3 was the planning of student evaluations. In the experts' assessment, the module complied with pedagogical and technical requirements most of the time. In the practical functioning stage, 10 h were dedicated for on-site activities and 10 h for distance activities. Most students (93.2%) were women between 19 and 23 yr of age (75%). The internet was the most used means to remain updated for 23 students (59.0%), and 30 students (68.2%) accessed it from the teaching institution. A personal computer was used by 23 students (56.1%), and most of them (58.1%) learned to use it alone. Access to a forum was more dispersed (variation coefficient: 86.80%) than access to chat (variation coefficient: 65.14%). Average participation was 30 students in forums and 22 students in the chat. Students' final grades in the module averaged 8.5 (SD: 1.2). TelEduc was shown to be efficient in supporting the teaching- learning process of endocrine physiology.

Robotic Resection of Intraductal Neoplasm of the Pancreas

Background: Minimally invasive techniques have been revolutionary and provide clinical evidence of decreased morbidity and comparable efficacy to traditional open surgery. Computer-assisted surgical devices have recently been approved for general surgical use. Aim: The aim of this study was to report the first known case of pancreatic resection with the use of a computer-assisted, or robotic, surgical device in Latin America. Patient and Methods: A 37-year-old female with a previous history of radical mastectomy for bilateral breast cancer due to a BRCA2 mutation presented with an acute pancreatitis episode. Radiologic investigation disclosed an intraductal pancreatic neoplasm located in the neck of the pancreas with atrophy of the body and tail. The main pancreatic duct was enlarged. The surgical decision was to perform a laparoscopic subtotal pancreatectomy, using the da Vinci (R) robotic system (Intuitive Surgical, Sunnyvale, CA). Five trocars were used. Pancreatic transection was achieved with vascular endoscopic stapler. The surgical specimen was removed without an additional incision. Results: Operative time was 240 minutes. Blood loss was minimal, and the patient did not receive a transfusion. The recovery was uneventful, and the patient was discharged on postoperative day 4. Conclusions: The subtotal laparoscopic pancreatic resection can safely be performed. The da Vinci robotic system allowed for technical refinements of laparoscopic pancreatic resection. Robotic assistance improved the dissection and control of major blood vessels due to three-dimensional visualization of the operative field and instruments with wrist-type end-effectors.

Primary Hyperparathyroidism as the First Clinical Manifestation of Multiple Endocrine Neoplasia Type 2A in a 5-Year-Old Child

Background: Primary hyperparathyroidism occurs in only 10%-30% of patients with multiple endocrine neoplasia type 2A (MEN2A), rarely as the sole clinical manifestation, and is usually diagnosed after the third decade of life. Summary: A5-year-old girl was referred for prophylactic thyroidectomy as she carried the p.C634R RET mutation. She was clinically asymptomatic, with a normally palpable thyroid and with the cervical region free of lymphadenopathy or other nodules. Preoperative tests revealed hypercalcemia associated with elevation of parathyroid hormone (PTH) (calcium = 11.2mg/dL, calcium ion = 1.48mmol/L, phosphorus = 4.0 mg/dL, alkaline phosphatase = 625U/L, parathyroid hormone (PTH) PTH = 998 pg/mL). A thyroid ultrasound was normal and parathyroid scintigraphy with (99m)Tc-Sestamibi revealed an area of radioconcentration in the upper half of the left thyroid lobe suggesting hyperfunctioning parathyroid tissue. She underwent total thyroidectomy and parathyroidectomy and developed hypocalcemia. The anatomopathological examination showed no histopathological changes in the thyroid tissue and an adenoma of the parathyroid gland, confirming the diagnosis of hyperparathyroidism. Conclusions: Primary hyperparathyroidism can be a precocious manifestation of MEN2A. This case report highlights that asymptomatic hypercalcemia should be scrutinized in children related to patients with MEN2A who carry a mutation in the RET proto-oncogene, especially mutations in the codon 634, before the currently recommended age of 8 years.

Management of Neuroendocrine Tumors: A Meeting of Experts from Latin America

A panel of experts from Latin America convened in Brazil, in May of 2007, for consensus recommendations regarding the management of neuroendocrine tumors ( NETs) of the gastrointestinal tract and pancreas. The recently introduced World Health Organization classification of NETs represents a step forward, but the former classification of carcinoids into foregut, midgut and hindgut is still likely to be useful in the near future. Macroscopic description of the tumor should be followed by light microscopic examination and immunohistochemical staining, whereas other techniques might not be widely available in Latin America. Surgery remains the mainstay of treatment for patients with potentially curable tumors, and adequate selection is paramount in order to optimize treatment results. Regarding systemic therapy, patients with well-differentiated tumors or islet-cell carcinomas may be categorized as having indolent disease, while patients with poorly differentiated, anaplastic, and small-cell carcinomas, or with atypical carcinoids, may be approached initially as having aggressive disease. Somatostatin analogues play a cytostatic role in indolent tumors, and chemotherapy may play a role against other, more aggressive NETs. Obviously, there is an urgent need for novel therapies that are effective against NETs. Copyright (C) 2008 S. Karger AG, Basel

Risk Profiles and Penetrance Estimations in Multiple Endocrine Neoplasia Type 2A Caused by Germline RET Mutations Located in Exon 10

Multiple endocrine neoplasia type 2 is characterized by germline mutations in RET. For exon 10, comprehensive molecular and corresponding phenotypic data are scarce. The International RET Exon 10 Consortium, comprising 27 centers from 15 countries, analyzed patients with RET exon 10 mutations for clinical-risk profiles. Presentation, age-dependent penetrance, and stage at presentation of medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism were studied. A total of 340 subjects from 103 families, age 4-86, were registered. There were 21 distinct single nucleotide germline mutations located in codons 609 (45 subjects), 611 (50), 618 (94), and 620 (151). MTC was present in 263 registrants, pheochromocytoma in 54, and hyperparathyroidism in 8 subjects. Of the patients with MTC, 53% were detected when asymptomatic, and among those with pheochromocytoma, 54%. Penetrance for MTC was 4% by age 10, 25% by 25, and 80% by 50. Codon-associated penetrance by age 50 ranged from 60% (codon 611) to 86% (620). More advanced stage and increasing risk of metastases correlated with mutation in codon position (609-620) near the juxtamembrane domain. Our data provide rigorous bases for timing of premorbid diagnosis and personalized treatment/prophylactic procedure decisions depending on specific RET exon 10 codons affected. Hum Mutat 32:51-58, 2011. (C) 2010 Wiley-Liss, Inc.

Conversion to Sirolimus in Kidney-Pancreas and Pancreas Transplantation

Reports on the use of sirolimus (SRL) in pancreas transplantation are still limited. The aim of this study was to evaluate the outcome of SRL conversion in pancreas transplant patients. Among 247 patients undergoing simultaneous kidney-pancreas or solitary pancreas transplantation, 33 (13%) were converted to SRL. The reasons for conversion were calcineurin inhibitors (CNI) nephrotoxicity (n = 24; 73%), severe neurotoxicity owing to CNI (n = 1; 3%), severe and/or recurrent acute rejection episodes (n = 7; 21.%), gastrointestinal (GI) side effects of mycophenolate mofetil (MMF; n = 5; 15%), and hyperglycemia (n = 4; 12%). Before conversion, all patients were maintained on a CNI, MMF, and low-dose steroids. They were gradually converted to SRL associated with either CNI or MMF withdrawal. Sixty-three percent (n = 15) of patients who were converted owing to CNI nephrotoxicity, showed stable or improved renal function. At 12 months after conversion, serum creatinine levels were significantly decreased in this group (2.2 +/- 0.5 vs 1.6 +/- 0.3 mg/dL; P = .001) and C-peptide values increased (2.9 +/- 1.1.1 vs 3.1 +/- 1.3 nmol/L; P = .01.8). The only patient with leucoencephalopathy showed improved neurologic status after SRL conversion. All patients converted to SRL because of GI side effects of MMF showed improvements, and none of those converted because of hyperglycemia experienced improvement. There were no episodes of acute rejection after conversion. We concluded that conversion to SRL in pancreas transplantation should be considered an important alternative strategy, particularly for CNI nephrotoxicity and neurotoxicity, and in cases of severe diarrhea due to MMF.

Laparoscopic Duodenal-Jejunal Bypass for the Treatment of Duodenal Obstruction Caused by Annular Pancreas: Description of a Surgical Technique

Annular pancreas is a rare congenital anomaly, which is only surgically treated in symptomatic cases. Surgical treatment consists of bypassing the duodenal transit by gastrojejunal or duodenal-jejunal anastomosis. In the absolute majority of published cases, laparotomy is the most widely used access technique. The aim of this article is to report a case of an annular pancreas and describe the technical steps involved in carrying out a laparoscopic duodenal-jejunal anastomosis, for correction of the duodenal obstruction. The patient`s recovery was uneventful; she was discharged on the fourth postoperative day and remained asymptomatic for the 2-year, outpatient follow-up period. Laparoscopic duodenal-jejunal bypass is shown to be feasible and safe, and produce less surgical trauma, when carried out by an experienced surgeon who is duly trained and familiar with the laparoscopic technique.

Solid pseudopapillary neoplasm of the pancreas: distinct patterns of onset, diagnosis, and prognosis for male versus female patients

Background. Solid pseudopapillary neoplasm of the pancreas is a distinctive pancreatic neoplasm with low metastatic potential. This study examines clinical differences and prognosis between male and female Patients. Methods. The medical records of 34 consecutive patients with pancreatic solid pseudopapillaly neoplasms between 1990 and 2006 were reviewed. Whenever feasible, organ-preserving operation was performed. Statistical analysis was performed using chi-square and Student t test. Results. There were 27 women (79%) and seven men (21%) with median age of 23 years. Mean diameter of the tumor was 7 cm. Tumor size tended to be smaller in patients treated in more recent years. Conservative surgery was possible in I I patients including spleen-preserving distal pancreatectomy in 3, central pancreatectomy in 5, and enucleation in 3 patients. Median hospital stay was 11 days, morbidity rate was 62%, including 17 patients with grade A pancreatic fistula, and there was no operative mortality. Mean follow-up time was 84 months. Tumor recurred in 2 patients (6%). Overall late morbidity rate was 12%. At the time of diagnosis, age was ((x) over bar +/- SD) higher among male patients (25 +/- 2 years vs 37 +/- 7 years, P < .05) with no difference in tumor size. The neoplasms were more aggressive in male Patients; therefore, conservative surgery was less likely. There was no correlation between tumor aggressiveness and age of the patient or size of tumor. Conclusion. This is the first single center study to demonstrate that solid pseudopapillary neoplasms in male patients have distinct Patterns Of onset and aggressiveness when compared with female patients. Although valid prognostic criteria are still lacking, it appears that male patients may be best treated by more radical operation and should be observed more closely during follow-up.

Multiple endocrine neoplasia type 1 in Brazil: MEN1 founding mutation, clinical features, and bone mineral density profile

Objective: Only few large families with multiple endocrine neoplasia type 1 (MEN1) have been documented. Here, we aimed to investigate the clinical features of a seven-generation Brazilian pedigree. which included 715 at-risk family members. Design: Genealogical and geographic analysis was used to identify the MEN1 pedigree. Clinical and genetic approach was applied to characterize the phenotypic and genotypic features of the family members. Results: Our genetic data indicated that a founding mutation in the MEN1 gene has occurred in this extended Brazilian family. Fifty family members were diagnosed with MEN1. Very high frequencies of functioning and non-functioning MEN1-related tumors were documented and the prevalence of prolactinoma (29.6%) was similar to that previously described in prolactinoma-variant Burin (32%). In addition, bone mineral density analysis revealed severe osteoporosis (T,-2.87 +/- 0.32) of compact bone (distal radius) in hyperparathyroidism (HPT)/MEN1 patients. while marked bone mineral loss in the lumbar spine (T,-1.95 +/- 0.39). with most cancellous bone, and femoral neck (mixed composition: T,-1.48 +/- 0.27) were also present. Conclusions: In this study, we described clinically and genetically the fifth largest MEN1 family in the literature. Our data confirm previous findings suggesting that prevalence of MEN1-related tumors in large families may differ from reports combining cumulative data of small families. Furthermore. we were able to evaluate the bone status in HPT/MEN1 cases, a subject that has been incompletely approached in the literature. We discussed the bone loss pattern found in our MEN1 patients comparing with that of patients with sporadic primary HPT.