Gain-of-function variants in NLRP1 protect against the development of diabetic kidney disease: NLRP1 inflammasome role in metabolic stress sensing?

Although inflammasome plays a well-known role in animal models of renal injury, limited studies in humans are available, and its participation in diabetic kidney disease (DKD) remains unknown. Aim of this study was to elucidate the contribution of inflammasome genetics in the development of DKD in type-1 diabetes (T1D). The association of functional variants in inflammasome genes with DKD was assessed by multivariate analysis in a retrospective and in a prospective cohort. NLRP1 rs2670660 and rs11651270 polymorphisms were significantly associated with a decrease risk to develop DKD (padj<0.01), and rs11651270 also with a lower risk of new renal events during follow-up (padj=0.01). Supporting these findings, diabetes metabolites (glycated albumin and high glucose) were able to modulate NLRP1 expression. This study is the first to suggest a protective role of NLRP1 in DKD, highlighting an emerging role of NLRP1 as a homeostatic factor against metabolic stress.

In type 2 diabetes mellitus glycated albumin alters macrophage gene expression impairing ABCA1-mediated cholesterol efflux.

Advanced glycation end products (AGE) are elevated in diabetes mellitus (DM) and predict the development of atherosclerosis. AGE-albumin induces oxidative stress, which is linked to a reduction in ABCA-1 and cholesterol efflux. We characterized the glycation level of human serum albumin (HSA) isolated from poorly controlled DM2 (n = 11) patients compared with that of control (C, n = 12) individuals and determined the mechanism by which DM2-HSA can interfere in macrophage lipid accumulation. The HSA glycation level was analyzed by MALDI/MS. Macrophages were treated for 18 h with C- or DM2-HSA to measure the (14) C-cholesterol efflux, the intracellular lipid accumulation and the cellular ABCA-1 protein content. Agilent arrays (44000 probes) were used to analyze gene expression, and the differentially expressed genes were validated by real-time RT-PCR. An increased mean mass was observed in DM2-HSA compared with C-HSA, reflecting the condensation of at least 5 units of glucose. The cholesterol efflux mediated by apo AI, HDL3 , and HDL2 was impaired in DM2-HSA-treated cells, which was related to greater intracellular lipid accumulation. DM2-HSA decreased Abcg1 mRNA expression by 26%. Abca1 mRNA was unchanged, although the final ABCA-1 protein content decreased. Compared with C-HAS-treated cells, NADPH oxidase 4 mRNA expression increased in cells after DM2-HSA treatment. Stearoyl-Coenzyme A desaturase 1, janus kinase 2, and low density lipoprotein receptor mRNAs were reduced by DM2-HSA. The level of glycation that occurs in vivo in DM2-HSA-treated cells selectively alters macrophage gene expression, impairing cholesterol efflux and eliciting intracellular lipid accumulation, which contribute to atherogenesis, in individuals with DM2.

Dual effect of advanced glycation end products in pancreatic islet apoptosis.

BACKGROUND: Loss of ß-cell function hastens deterioration of metabolic control in type 2 diabetes patients. Besides amyloid deposit and glucolipotoxicity, advanced glycation end products (AGEs) acting through their receptors (RAGE) seem to contribute to this process by promoting islet apoptosis. In order to investigate the role of AGEs in ß-cell deterioration, we evaluated the temporal and dose effects of AGE compounds on apoptosis rate, reactive oxygen species generation and expression of pro-apoptotic and anti-apoptotic genes in cultured islets. METHODS: Rat pancreatic islets were exposed or not for 24, 48, 72 and 96 h to albumin modified by glycoaldehyde. Apoptosis, reactive oxygen species and superoxide content and NADPH oxidase activity were evaluated as well as RNA expression of the genes Ager (codes for RAGE), Bax, Bcl2 and Nfkb1. RESULTS: In 24 and 48 h, glycoaldehyde elicited a decrease in apoptosis rate in comparison with the control condition concomitantly with a reduction in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In contrast, after 72 and 96 h, glycoaldehyde promoted an increase in apoptosis rate concomitantly with an increase in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In 24 h, glycoaldehyde elicited a decrease in the islet content of reactive oxygen species, whereas after 48 and 72 h, it promoted an opposite effect, increasing superoxide generation. The NADPH oxidase inhibitor VAS2870 attenuated superoxide production, implicating NADPH oxidase as an important source of reactive oxygen species in islets exposed to AGEs. CONCLUSIONS: Albumin modified by glycoaldehyde exerted a dual effect in cultured pancreatic islets, being protective against apoptosis after short exposure but pro-apoptotic after prolonged exposure.

Advanced glycated albumin isolated from poorly controlled type 1 diabetes mellitus patients alters macrophage gene expression impairing ABCA-1-mediated reverse cholesterol transport.

BACKGROUND: We evaluated the effects of albumin isolated from control individuals and from patients with poorly controlled type 1 diabetes mellitus on macrophage gene expression and on reverse cholesterol transport. METHODS: Serum albumin was purified from control subjects (n = 12) and from patients with poorly controlled type 1 diabetes mellitus (n = 13). (14)C-cholesterol-labelled J774 macrophages treated with albumin were employed to measure cholesterol efflux mediated by apo A-I, HDL(3) or HDL(2), the intracellular lipid accumulation and the cellular ABCA-1 protein content. Agilent arrays (44000 probes) were used to analyse gene expression. Several differentially expressed genes were validated by real-time reverse transcription-PCR using TaqMan Two Step RT-PCR. RESULTS: Levels of glycation-modified and (carboxymethyl)lysine-modified albumin were higher in diabetic patients than in control subjects. Apo A-I-mediated and HDL(2)-mediated cellular cholesterol efflux were impaired in macrophages treated with albumin from diabetic patients in comparison with control albumin-treated cells, which was attributed to the reduction in ABCA-1 protein content. Even in the presence of cholesterol acceptors, a higher level of intracellular lipid was observed in macrophages exposed to albumin from diabetic individuals in comparison with the control. The reduction in ABCA-1 content was associated with enhanced expression of stearoyl CoA desaturase 1 and decreased expression of janus kinase 2, which were induced by albumin from patients with type 1 diabetes mellitus. CONCLUSIONS: (Carboxymethyl)lysine-modified albumin isolated from poorly controlled type 1 diabetic patients impairs ABCA-1-mediated reverse cholesterol transport and elicits intracellular lipid accumulation, possibly contributing to atherosclerosis.

Cardiovascular risk and mortality in end-stage renal disease patients undergoing dialysis: sleep study, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life: a prospective, double blind, randomized controlled clinical trial.

BACKGROUND: Chronic kidney disease (CKD) is one of the most serious public health problems. The increasing prevalence of CKD in developed and developing countries has led to a global epidemic. The hypothesis proposed is that patients undergoing dialysis would experience a marked negative influence on physiological variables of sleep and autonomic nervous system activity, compromising quality of life. METHODS/DESIGN: A prospective, consecutive, double blind, randomized controlled clinical trial is proposed to address the effect of dialysis on sleep, pulmonary function, respiratory mechanics, upper airway collapsibility, autonomic nervous activity, depression, anxiety, stress and quality of life in patients with CKD. The measurement protocol will include body weight (kg); height (cm); body mass index calculated as weight/height(2); circumferences (cm) of the neck, waist, and hip; heart and respiratory rates; blood pressures; Mallampati index; tonsil index; heart rate variability; maximum ventilatory pressures; negative expiratory pressure test, and polysomnography (sleep study), as well as the administration of specific questionnaires addressing sleep apnea, excessive daytime sleepiness, depression, anxiety, stress, and quality of life. DISCUSSION: CKD is a major public health problem worldwide, and its incidence has increased in part by the increased life expectancy and increasing number of cases of diabetes mellitus and hypertension. Sleep disorders are common in patients with renal insufficiency. Our hypothesis is that the weather weight gain due to volume overload observed during interdialytic period will influence the degree of collapsibility of the upper airway due to narrowing and predispose to upper airway occlusion during sleep, and to investigate the negative influences of haemodialysis in the physiological variables of sleep, and autonomic nervous system, and respiratory mechanics and thereby compromise the quality of life of patients. TRIAL REGISTRATION: The protocol for this study is registered with the Brazilian Registry of Clinical Trials (ReBEC RBR-7yhr4w and World Health Organization under Universal Trial Number UTN: U1111-1127-9390 [http://www.ensaiosclinicos.gov.br/rg/RBR-7yhr4w/]).

Association of genetic variants in the promoter region of genes encoding p22phox (CYBA) and glutamate cysteine ligase catalytic subunit (GCLC) and renal disease in patients with type 1 diabetes mellitus.

BACKGROUND: Oxidative stress is recognized as a major pathogenic factor of cellular damage caused by hyperglycemia. NOX/NADPH oxidases generate reactive oxygen species and NOX1, NOX2 and NOX4 isoforms are expressed in kidney and require association with subunit p22phox (encoded by the CYBA gene). Increased expression of p22phox was described in animal models of diabetic nephropathy. In the opposite direction, glutathione is one of the main endogenous antioxidants whose plasmatic concentrations were reported to be reduced in diabetes patients. The aim of the present investigation was to test whether functional single nucleotide polymorphisms (SNPs) in genes involved in the generation of NADPH-dependent O2•⁻ (-675 T → A in CYBA, unregistered) and in glutathione metabolism (-129 C → T in GCLC [rs17883901] and -65 T → C in GPX3 [rs8177412]) confer susceptibility to renal disease in type 1 diabetes patients. METHODS: 401 patients were sorted into two groups according to the presence (n = 104) or absence (n = 196) of overt diabetic nephropathy or according to glomerular filtration rate (GFR) estimated by Modification of Diet in Renal Disease (MDRD) equation: ≥ 60 mL (n = 265) or < 60 mL/min/1.73 m² (n = 136) and were genotyped. RESULTS: No differences were found in the frequency of genotypes between diabetic and non-diabetic subjects. The frequency of GFR < 60 mL/min was significantly lower in the group of patients carrying CYBA genotypes T/A+A/A (18.7%) than in the group carrying the T/T genotype (35.3%) (P = 0.0143) and the frequency of GFR < 60 mL/min was significantly higher in the group of patients carrying GCLC genotypes C/T+T/T (47.1%) than in the group carrying the C/C genotype (31.1%) (p = 0.0082). Logistic regression analysis identified the presence of at least one A allele of the CYBA SNP as an independent protection factor against decreased GFR (OR = 0.38, CI95% 0.14-0.88, p = 0.0354) and the presence of at least one T allele of the GCLC rs17883901 SNP as an independent risk factor for decreased GFR (OR = 2.40, CI95% 1.27-4.56, p = 0.0068). CONCLUSIONS: The functional SNPs CYBA -675 T → A and GCLC rs17883901, probably associated with cellular redox imbalances, modulate the risk for renal disease in the studied population of type 1 diabetes patients and require validation in additional cohorts.

Genes differentially expressed in prolactinomas responsive and resistant to dopamine agonists.

BACKGROUND/AIMS: Prolactin (PRL) secretion and its gene expression are inhibited by dopamine. Prolactinomas are the most common secreting pituitary adenomas, and dopamine agonists (DA) are the first choice for their treatment. However, a subset of patients is resistant to DA. As the mechanisms involved in DA resistance are not fully understood, the aim of this study was to obtain new insights regarding the molecular differences between the prolactinomas that are responsive to DA and those that are resistant. METHODS: Tumor tissue samples were collected from 17 patients who harbored prolactinomas, which were classified as responsive or resistant according to their clinical and laboratorial reaction to DA. The expression of 6 genes was evaluated by real-time polymerase chain reaction: dopamine receptor type 2 (DRD(2)), nerve growth factor-beta (NGFB) and its receptor (NGFR), estrogen receptor-alpha (ERA), estrogen receptor-beta (ERB) and the pituitary tumor transforming gene (PTTG). RESULTS: Median DRD(2) and NGFR expression in responsive patients was significantly higher than in resistant ones (p = 0.029 and p = 0.020, respectively). Moreover, the expressions of DRD(2) and NGFR were positively correlated with PRL decrease during treatment (r = 0.66, p = 0.005 and r = 0.57, p = 0.044, respectively). Furthermore, ERB expression was positively correlated to PTTG expression (r = 0.68, p = 0.032) and negatively correlated to NGFB expression (r = -0.75, p = 0.02). CONCLUSIONS: DRD(2) and NGFR expressions are related to the responsiveness of prolactinoma to DA. However, PTTG, ERB and ERA expressions are not. Also ERB, ERA and PTTG expressions did not present a clear correlation to tumor aggressiveness. Furthermore, the response of prolactinomas to DA should be viewed as a spectrum ranging from the most responsive to the most resistant ones.

Acromegaly: correlation between expression of somatostatin receptor subtypes and response to octreotide-lar treatment.

About one-third of acromegalics are resistant to the clinically available somatostatin analogs (SA). The resistance is related to density reduction or different expression of somatostatin receptor subtypes (SSTR). This study analyzes SSTR's expression in somatotrophinomas, comparing to SA response, hormonal levels, and tumor volume. We analyzed 39 somatotrophinomas; 49% were treated with SA. The most expressed SSTR was SSTR5, SSTR3, SSTR2, SSTR1, and SSTR4, respectively. SSTR1 and SSTR2 had higher expression in patients that had normalized GH and IGF-I. SSTR3 was more expressed in patients with tumor reduction. There was a positive correlation between the percentage of tumor reduction and SSTR1, SSTR2 and SSTR3 expression. Also, a positive correlation between SSTR2 mRNA expression and the immunohistochemical reactivity of SSTR2 was found. Our study confirmed the association between the SA response to GH and IGF-I and the SSTR2. Additionally, this finding was also demonstrated in relation to SSTR1.

Diabetes induces tri-methylation at lysine 9 of histone 3 at Slc2a4 gene in skeletal muscle: A new target to improve glycemic control.

Expression of the glucose transporter GLUT4, encoded by Slc2a4 gene, is reduced in both type 1 and type 2 diabetes (T1D and T2D), contributing to glycemic impairment. The present study investigated epigenetic regulations at the Slc2a4 promoter in skeletal muscle of T1D- and T2D-like experimental models. Slc2a4/GLUT4 repression was observed in T1D and T2D and that was reversed by insulin and resveratrol treatments, respectively. In both T1D-like and T2D-like animals, tri-methylation at lysine 9 of histone 3 (H3K9me3) increased in the Slc2a4 enhancer segment, whereas MEF2A/D binding into this segment was reduced; all effects were reversed by respective treatments. This study reveals that increased H3K9me3 in the Slc2a4 promoter enhancer segment contributes to reduce GLUT4 expression in skeletal muscle and to worse glycemic control in diabetes, pointing to the H3K9me3 of Slc2a4 promoter as a potential target for development of new approaches for treating diabetes.

Serpin peptidase inhibitor clade A member 1 as a potential marker for malignancy in insulinomas.

PURPOSE: The biological behavior of insulinomas cannot be predicted based on histopathologic criteria in which the diagnosis of malignancy is confirmed by the presence of metastases. In this study, microarray and quantitative real-time reverse transcription-PCR were applied to identify differentially expressed genes between malignant and nonmalignant insulinomas to search for useful biomarkers to recognize the metastatic potential of insulinomas. EXPERIMENTAL DESIGN: Code Link human bioarrays were used to analyze differences in approximately 20,000 genes between six well-differentiated endocrine tumors of benign behavior compared with one well-differentiated endocrine carcinoma (WDEC) and three metastases of endocrine carcinomas (MEC). Quantitative real-time reverse transcription-PCR was used to validate differential expressions of five genes in a series of 35 sporadic insulinomas. Serpin peptidase inhibitor clade A member 1 (SERPINA1; alpha-1-antitrypsin) expression, identified as up-regulated in malignant insulinomas, was also evaluated by immunohistochemistry. RESULTS: Analysis of microarray data resulted in 230 differentially expressed genes. Gene Ontology analysis identified serine-type endopeptidase activity and serine-type endopeptidase inhibitor activity as pathways presenting significant differential expression. Protease serine 2 and complement factor B (from serine-type endopeptidase activity pathway) were respectively confirmed as up-regulated in well-differentiated endocrine tumors of benign behavior (WDET) and in WDEC/MEC. Angiotensinogen and SERPINA1 (from serine-type endopeptidase inhibitor activity pathway) were confirmed as up-regulated in WDEC/MEC. SERPINA1 was shown to be expressed in 85.7% of malignant versus 14.3% of nonmalignant insulinomas by immunohistochemistry. CONCLUSIONS: Our data are consistent to the possibility that SERPINA1 is a marker of malignancy in insulinomas. Given the widespread availability of antibody anti-alpha-1-antitrypsin in pathology services, SERPINA1 expression evaluation might be of clinical utility in recognizing patients more likely to develop an aggressive presentation.

A Prospective Randomized Controlled Trial of the Metabolic Effects of Sleeve Gastrectomy with Transit Bipartition.

PURPOSE: To compare the effects of the sleeve gastrectomy with transit bipartition (SG + TB) procedure with standard medical therapy (SMT) in mildly obese patients with type II diabetes (T2D). METHODS: This is a prospective, randomized, controlled trial. Twenty male adults, ≤ 65 years old, with T2D, body mass index (BMI) > 28 kg/m2 and < 35 kg/m2, and HbA1c level > 8% were randomized to SG + TB or to SMT. Outcomes were the remission in the metabolic and cardiovascular risk variables up to 24 months. RESULTS: At 24 months, SG + TB group showed a significant decrease in HbaA1c values (9.3 ± 2.1 versus 5.5 ± 1.1%, P = < 0.05) whereas SMT group maintained similar levels from baseline (8.0 ± 1.5 versus 8.3 ± 1.1%, P = NS). BMI values were lower in the SG + TB group (25.3 ± 2.8 kg/m2 versus 30.9 ± 2.5 kg/m2; P = < 0.001). At 24 months, none patient in SG + TB group needed medications for hyperlipidemia/hypertension. HDL-cholesterol levels increased in the SG + TB group (33 ± 8 to 45 ± 15 mg/dL, P < 0.001). After 24 months, the area under the curve (AUC) of GLP1 increased and in the SG + TB group and the AUC of the GIP concentrations was lower in the SG + TB group than in the SMT. At 3 months, SG + TB group showed a marked increase in FGF19 levels (74.1 ± 45.8 to 237.3 ± 234 pg/mL; P = 0.001). CONCLUSIONS: SG + TB is superior to SMT and was associated with a better metabolic and cardiovascular profile.

Dietary advanced glycated end-products and medicines influence the expression of SIRT1 and DDOST in peripheral mononuclear cells from long-term type 1 diabetes patients.

Quantitative polymerase chain reaction was employed to quantify expression of two genes coding for advanced glycation end-product receptors [RAGE ( AGER) and AGER1 ( DDOST)] and of the gene coding the deacetylase SIRT1 ( SIRT1) in peripheral blood mononuclear cells from type 1 diabetes patients without [Group A, n = 35; 28.5 (24-39) years old; median (interquartile interval)] or with at least one microvascular complication [Group B, n = 117; 34.5 (30-42) years old]; 31 healthy controls were also included. In a subgroup of 48 patients, daily advanced glycation end-products intake before blood collection was assessed. Lower expression of DDOST was found in patients than in controls after adjustment for sex, age, use of statins, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Higher expressions of AGER, DDOST and SIRT1 were observed in Group A. Stratifying by complications, AGER and DDOST expressions were higher in those without retinopathy and without diabetic kidney disease, respectively, compared to patients with these complications. Patients using statins or angiotensin receptor blockers presented higher expression of DDOST. Expression of SIRT1 was higher in patients consuming ≥12,872 KU daily of advanced glycation end-products. Although AGER, DDOST and SIRT1 are differently expressed in peripheral blood mononuclear cells from type 1 diabetes patients with and without microvascular complications, they are also influenced by dietary advanced glycation end-products and by statins and angiotensin receptor blockers.

PTTG expression in different experimental and human prolactinomas in relation to dopaminergic control of lactotropes.

BACKGROUND: Pituitary tumor transforming gene (pttg) is a novel oncogene that is expressed at higher level in most of the tumors analyzed to date compared to normal tissues. Nevertheless, its expression in prolactinomas and its relation with the pituitary dopamine receptor 2 (D2R) are not well defined. We sought to determine the pituitary level of pttg in three different experimental models of prolactinomas with altered dopaminergic control of the pituitary: the dopaminergic D2R knockout female mouse, the estrogen-treated rat, and the senescent female rat. These three models shared the characteristics of increased pituitary weight, hyperprolactinemia, lactotrope hyperplasia and reduced or absent dopaminergic action at the pituitary level. We also studied samples from human macroprolactinomas, which were characterized as responsive or resistant to dopamine agonist therapy. RESULTS: When compared to female wild-type mice, pituitaries from female D2R knockout mice had decreased PTTG concentration, while no difference in pttg mRNA level was found. In senescent rats no difference in pituitary PTTG protein expression was found when compared to young rats. But, in young female rats treated with a synthetic estrogen (Diethylstylbestrol, 20 mg) PTTG protein expression was enhanced (P = 0.029). Therefore, in the three experimental models of prolactinomas, pituitary size was increased and there was hyperprolactinemia, but PTTG levels followed different patterns.Patients with macroprolactinomas were divided in those in which dopaminergic therapy normalized or failed to normalize prolactin levels (responsive and resistant, respectively). When pituitary pttg mRNA level was analyzed in these macroprolactinomas, no differences were found. We next analyzed estrogen action at the pituitary by measuring pituitary estrogen receptor alpha levels. The D2R knockout female mice have low estrogen levels and in accordance, pituitary estrogen receptors were increased (P = 0.047). On the other hand, in senescent rats estrogen levels were slightly though not significantly higher, and estrogen receptors were similar between groups. The estrogen-treated rats had high pharmacological levels of the synthetic estrogen, and estrogen receptors were markedly lower than in controls (P < 0.0001). Finally, in patients with dopamine resistant or responsive prolactinomas no significant differences in estrogen receptor alpha levels were found. Therefore, pituitary PTTG was increased only if estrogen action was increased, which correlated with a decrease in pituitary estrogen receptor level. CONCLUSION: We conclude that PTTG does not correlate with prolactin levels or tumor size in animal models of prolactinoma, and its pituitary content is not related to a decrease in dopaminergic control of the lactotrope, but may be influenced by estrogen action at the pituitary level. Therefore it is increased only in prolactinomas generated by estrogen treatment, and not in prolactinomas arising from deficient dopamine control, or in dopamine resistant compared with dopamine responsive human prolactinomas. These results are important in the search for reliable prognostic indicators for patients with pituitary adenomas which will make tumor-specific therapy possible, and help to elucidate the poorly understood phenomenon of pituitary tumorigenesis.

Modulation of hepatic microsomal triglyceride transfer protein (MTP) induced by S-nitroso-N-acetylcysteine in ob/ob mice.

We evaluated the effects of a potent NO donor, S-nitroso-N-acetylcysteine (SNAC), on microsomal triglyceride transfer protein (MTP) expression in ob/ob mice. NAFLD was induced in male ob/ob mice using a methionine-choline deficient diet (MCD) concomitantly with oral SNAC fed solution (n=5) or vehicle (control; n=5) by gavage daily for 4 weeks. Livers were collected for histology and for assessing MTP by RT-qPCR, Western blot, immunohistochemistry and immunogold electron microscopy analyses. Histological analysis showed diffuse macro and microvesicular steatosis, moderate hepatocellular ballooning and moderate inflammatory infiltrate in ob/ob mice fed the MCD diet. With SNAC, mice showed a marked reduction in liver steatosis (p<0.01), in parenchymal inflammation (p=0.02) and in MTP protein immunoexpression in zone III (p=0.05). Moreover, SNAC caused reduction of MTP protein in Western blot analysis (p<0.05). In contrast, MTP mRNA content was significantly higher (p<0.05) in mice receiving SNAC. Immuno-electron microscopy showed MTP localized in the rough endoplasmic reticulum of hepatocytes in both treated and untreated groups. However with SNAC treatment, MTP was also observed surrounding fat globules. Histological improvement mediated by a nitric oxide donor is associated with significantly altered expression and distribution of MTP in this animal model of fatty liver disease. Further studies are in progress to examine possible mechanisms and to develop SNAC as a possible therapy for human fatty liver disease.

Correlation between the components of the insulin-like growth factor I system, nutritional status and visceral leishmaniasis.

The role of the insulin-like growth factor I (IGF-I) system and nutritional status was studied in 241 children from a Brazilian area endemic for visceral leishmaniasis (VL). Thirty-nine children had the active form, 20 were oligosymptomatic, 38 were asymptomatic and 144 were not infected. Serum concentrations of growth hormone (GH), total and free IGF-I and IGF binding-protein 3 (IGFBP3) were measured by radioimmunoassay. Nutritional status was evaluated by anthropometric indicators and biochemical measurements. Total and free IGF-I and IGFBP3 were significantly reduced in the active form. Z scores for total and free IGF-I and for IGFBP3 were found to be significantly lower for active VL and oligosymptomatic individuals than for asymptomatic individuals, but never reached values

Type 2 Diabetes Remission After Roux-en-Y Gastric Bypass: Evidence for Increased Expression of Jejunal Genes Encoding Regenerating Pancreatic Islet-Derived Proteins as a Potential Mechanism.

BACKGROUND: Intestinal expression of regenerating pancreatic islet-derived protein-encoding genes (REG) would be enhanced after Roux-en-Y gastric bypass (RYGB) and would affect postoperative type 2 diabetes remission (T2Dr). METHODS: Intestinal biopsy samples were collected from 20 adult obese women with T2D before and 3 months after RYGB. Levels of REG expression and the gene encoding its putative receptor (EXTL3) were assessed by microarray and validated by quantitative RT-PCR. T2Dr was assessed according to ADA criteria 1 year after RYGB. RESULTS: After RYGB, only patients with T2Dr had significantly increased REG1α and REG3γ expression in the jejunum, as validated by quantitative RT-PCR. CONCLUSIONS: Our data provide support for the hypothesis that increased jejunal expression of REG genes after RYGB affects T2Dr, possibly by playing an endocrine function.

Understanding the barriers and improving care in type 2 diabetes: Brazilian perspective in time to do more in diabetes.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a complex disease, particularly in a continental country like Brazil. We attempted to understand and evaluate the perceptions and routines of Brazilians with T2DM and physicians, compared with other countries. METHODS: We compared the results from a 20-min online survey in Brazil with simultaneously collated data from India, Japan, Spain, UK and USA. RESULTS: In total, 652 adults with T2DM and 337 treating physicians were enrolled, of whom 100 patients and 55 physicians were from Brazil. The numbers of primary care physicians from the five countries were 221 versus 43 in Brazil, diabetes specialists were 61 versus 12. There was disconnect between the opinions of physicians and people with diabetes globally. Further, there were differences between clinical practices in Brazil versus the rest of the world, in many areas Brazilians were performing better. CONCLUSIONS: Communication between patients and physicians should be clearer. There is an urgent need to identify the deficits in education, in order to address the clinical inertia within the diabetes management team. There is a necessity to understand the specific requirements of the Brazilian population in order to contextualise international guidelines and implement local changes in practice.

Tissue-specific methylation profile in obese patients with type 2 diabetes before and after Roux-en-Y gastric bypass.

Eating habits, lifestyles, and exposure to specific environmental factors can greatly impact the risk of developing type 2 diabetes (T2D), influence the genome epigenetically, and affect the expression of genes, including genes related to glycemic control, at any stage of life. The epigenetic mechanism underlying obesity and T2D pathogenesis remains poorly understood. Conventional strategies for the treatment of obesity and its comorbidities often have poor long-term adherence, and pharmacological interventions are limited. Bariatric surgery is the most effective current option to treat severe obesity, and Roux-en-Y gastric bypass (RYGB) is the most applied technique worldwide. Epigenetic changes differ depending on the approach used to treat obesity and its associated comorbidities (clinical or surgical). Compared to primary clinical care, bariatric surgery leads to much greater loss of body weight and higher remission rates of T2D and metabolic syndrome, with methylation profiles in promoter regions of genes in obese individuals becoming similar to those of normal-weight individuals. Bariatric surgery can influence DNA methylation in parallel with changes in gene expression pattern. Changes in clinical biomarkers that reflect improvements in glucose and lipid metabolism after RYGB often occur before major weight loss and are coordinated by surgery-induced changes in intestinal hormones. Therefore, the intestine methylation profile would assist in understanding the mechanisms involved in improved glycemic control after bariatric surgery. The main objectives in this area for the future are to identify epigenetic marks that could be used as early indicators of metabolic risk, and to develop treatments able to delay or even reverse these epigenetic changes. Studies that provide the "human epigenetic profile" will be of considerable value to identify tissue-specific epigenetic signatures and their role in the development of chronic diseases. Further studies should apply methods based on global analysis of the genome to identify methylated sites associated with disease and epigenetic marks associated with the remodeling response to bariatric surgery. This review describes the main epigenetic alterations associated with obesity and T2D and the potential role of RYGB in remodeling these changes.

Gastrointestinal Transcriptomic Response of Metabolic Vitamin B12 Pathways in Roux-en-Y Gastric Bypass.

OBJECTIVES: Vitamin B12 (B12) deficiency after Roux-en-Y gastric bypass (RYGB) is highly prevalent and may contribute to postoperative complications. Decreased production of intrinsic factor owing to gastric fundus removal is thought to have a major role, but other components of B12 metabolism may also be affected. We evaluated changes in the expression levels of multiple B12 pathway-encoding genes in gastrointestinal (GI) tissues to evaluate the potential roles in contributing to post-RYGB B12 deficiency. METHODS: During double-balloon enteroscopy, serial GI biopsies were collected from 20 obese women (age, 46.9±6.2 years; body mass index, 46.5±5.3 kg/m2) with adult-onset type 2 diabetes (fasting plasma glucose ≥126 mg/dl; hemoglobin A1c≥6.5%) before and, at the same site, 3 months after RYGB. Gene expression levels were assessed by the Affymetrix Human GeneChip 1.0 ST microarray. Findings were validated by real-time quantitative PCR (RT-qPCR). RESULTS: Gene expression levels with significant changes (P≤0.05) included: transcobalamin I (TCN1) in remnant (-1.914-fold) and excluded (-1.985-fold) gastric regions; gastric intrinsic factor (GIF) in duodenum (-0.725-fold); and cubilin (CUBN) in duodenum (+0.982-fold), jejunum (+1.311-fold), and ileum (+0.685-fold). Validation by RT-qPCR confirmed (P≤0.05) observed changes for TCN1 in the remnant gastric region (-0.132-fold) and CUBN in jejunum (+2.833-fold). CONCLUSIONS: RYGB affects multiple pathway-encoding genes that may be associated with postoperative B12 deficiency. Decreased TCN1 levels seem to be the main contributing factor. Increased CUBN levels suggest an adaptive genetic reprogramming of intestinal tissue aiming to compensate for impaired intestinal B12 delivery.

Somatostatin receptor subtype 5 (SSTR5) mRNA expression is related to histopathological features of cell proliferation in insulinomas.

Insulinomas are rare endocrine neoplasias that constitute the most frequent islet cell tumours. Somatostatin (SST) analogs are tentatively used to inhibit insulin secretion and control tumour growth in patients with local invasion or inoperative metastasis, but variable responses have been reported. Data regarding somatostatin receptor (SSTR) subtypes expression in insulinomas are conflicting. In this study, we evaluated 16 cases of primary insulinomas (including four primary plurihormonal tumours) and two hepatic metastases. Histopathological and immunohistochemical analysis for some features associated with tumour aggressiveness and semi-quantitative RT-PCR for SSTR1-5 and real-time qPCR for SSTR5 were performed. SSTR subtypes 1, 3, and 5 were expressed in 100%, SSTR2 in 89%, and SSTR4 only in 22% of the insulinomas. SSTR5 mRNA was positively correlated with histopathological features related to tumour aggressiveness (large tumour diameter, well-differentiated endocrine tumour with uncertain behaviour and higher number of cells with nuclear atypia). SSTR5 mRNA expression in primary insulinomas was lower than in primary plurihormonal tumours (P < 0.05). The observed positive correlation between SSTR5 expression and tumour size suggests that the use of SST analogues more specific to SSTR5 in the treatment of insulinomas deserves attention.