Modulation of Glucose Consumption and Uptake in HepG2 Cells by Aqueous Extracts from the Coelomic Fluid of the Edible Holothuria tubulosa Sea Cucumber.

The cell-free aqueous extract from the coelomic fluid of Holothuria tubulosa was prepared and examined for its glucose-lowering effect on HepG2 cells in vitro. In particular, employing a combination of cytochemical, flow cytometric, PCR, and protein blot techniques, we evaluated its role on glucose internalization and storage and on the upregulation and surface translocation of the two glucose transporters GLUT-2 and -4. The changes in expression, synthesis, and/or activation of the GLUT2-related transcription factor hepatocyte nuclear factor-1 alpha (HNF1α) and the GLUT-4-translocation regulatory factors insulin receptor substrate-1 (IRS-1) and AKT were also studied. Our results showed the improved glucose response by HepG2 cells, leading to an evident increase in glucose consumption/uptake and glycogen storage upon exposure. Moreover, the extract induced molecular reprogramming involving the upregulation of (i) IRS1 gene expression, (ii) the transcription and translation levels of HNF1α, AKT, and GLUT-4, (iii) the phosphorylation level of AKT, (iv) the synthesis of GLUT-2 protein, and (v) the translocation of GLUT-2 and -4 transporters onto the plasma membrane. Cumulatively, our results suggest that the coelomic fluid extract from H. tubulosa can be taken into consideration for the development of novel treatment agents against diabetes mellitus.

Identification of Variants Responsible for Monogenic Forms of Diabetes in Brazil.

Monogenic forms of diabetes mellitus may affect a significant number of patients of this disease, and it is an important molecular cause to be investigated. However, studies of the genetic causes of monogenic diabetes, especially in populations with mixed ethnic backgrounds, such as the one in Brazil, are scarce. The aim of this study was to screen several genes associated with monogenic diabetes in fifty-seven Brazilian patients with recurrence of the disease in their families and thirty-four relatives. Inclusion criteria were: Age of onset ≤ 40 years old, BMI < 30 kg/m², at least two affected generations and negative anti-GAD and anti-IA2 antibodies. MODY genes HNF4A, GCK, HNF1A, HNF1B, NEUROD1, KLF11, PAX4, INS, KCNJ11, and MT-TL1 were sequenced by Sanger sequencing. We identified a total of 20 patients with variants, 13 GCK-MODY, four HNF1A-MODY, and one variant in each of the following genes, HNF4A, HNF1B and MT-TL1. Segregation analysis was performed in 13 families. Four variants were novel, two in GCK (p.(Met115Val) [c.343A>G] and p.(Asp365GlufsTer95) [c.1094_1095insGCGA]) and two in HNF1A (p.(Tyr163Ter) [c.489C>G] and p.(Val380CysfsTer39) [c.1136_1137insC]). Here we highlight the importance of screening for monogenic diabetes in admixed populations.

PDX1-MODY: A rare missense mutation as a cause of monogenic diabetes.

Maturity-Onset Diabetes of the Young type 4 is a rare form of diabetes mellitus, caused by mutations in the PDX1 gene. However, only a few mutations in this gene have been associated as a cause of monogenic diabetes up to date. It makes difficult to create a clinical manifestation profile of this disease and, consequently, to improve the therapeutic management for these patients. Here we report a normal weight woman, diagnosed with diabetes mellitus at 27 years old, during her first pregnancy. At the time of the recruitment, she was 40 years old and had a body mass index of 23.9 kg/m2, glycated hemoglobin level of 9.6%, and fasting plasma glucose (FPG) of 254 mg/dL. She presented no diabetic complications and she was being treated with insulin. She reported a family history of diabetes mellitus characteristic of an autosomal dominant mode of inheritance. Molecular analysis of the PDX1 gene revealed the missense variant c.532G > A (p.(Glu178Lys)) segregating from the patient to her son, reported as diabetic. It was absent in her healthy daughter. The c.532G > A seems to be a rare variant, absent in human variants databases, and among 86 normoglycemic controls. Eight in silico algorithms classified this variant as probably pathogenic. Additionally, analysis of the evolutionary conservation showed the glutamic acid in the position 178 of PDX-1 protein as conserved among several species. Our findings reinforce the importance of screening rare MODY genes among families with suspicion of monogenic diabetes to help better understand the clinical manifestations of this disease.

Identification of the First PAX4-MODY Family Reported in Brazil.

PURPOSE: The aim of this study was to sequence the coding region of the PAX4 gene in a Brazilian cohort with clinical manifestations of monogenic diabetes. PATIENTS AND METHODS: This study included 31 patients with autosomal dominant history of diabetes, age at diagnosis ≤40 years, BMI <30 kg/m2, and no mutations in GCK or HNF1A, HNF4A, and HNF1B. Screening of the PAX4 coding region was performed by Sanger sequencing. In silico algorithms were used to assess the potential impact of amino acid substitutions on protein structure and function. Additionally, PAX4-MODY family members and 158 control subjects without diabetes were analyzed for the identified mutation. RESULTS: The molecular analysis of PAX4 has detected one missense mutation, p.Arg164Gln (c.491G>A), segregating with diabetes in a large Brazilian family. The mutation was absent among the control group. The index case is a woman diagnosed at 32 years of age with polyneuropathy and treated with insulin. She did not present diabetic renal disease or retinopathy. Family members with the PAX4 p.Arg164Gln mutation have a heterogeneous clinical manifestation and treatment response, with age at diagnosis ranging from 24 years to 50 years. CONCLUSION: To the best of our knowledge, this is the first study to report a PAX4-MODY family in Brazil. The age of PAX4-MODY diagnosis in the Brazilian family seems to be higher than the classical criteria for MODY. Our results reinforce the importance of screening large monogenic diabetes families for the understanding of the clinical manifestations of rare forms of diabetes for the specific and personalized treatment.

MODY probability calculator for GCK and HNF1A screening in a multiethnic background population

ABSTRACT Objective We aimed to identify the frequency of monogenic diabetes, which is poorly studied in multiethnic populations, due to GCK or HNF1A mutations in patients with suggestive clinical characteristics from the Brazilian population, as well as investigate if the MODY probability calculator (MPC) could help patients with their selection. Subjects and methods Inclusion criteria were patients with DM diagnosed before 35 years; body mass index < 30 kg/m2; negative autoantibodies; and family history of DM in two or more generations. We sequenced HNF1A in 27 patients and GCK in seven subjects with asymptomatic mild fasting hyperglycemia. In addition, we calculated MODY probability with MPC. Results We identified 11 mutations in 34 patients (32.3%). We found three novel mutations. In the GCK group, six cases had mutations (85.7%), and their MODY probability on MPC was higher than 50%. In the HNF1A group, five of 27 individuals had mutations (18.5%). The MPC was higher than 75% in 11 subjects (including all five cases with HNF1A mutations). Conclusion Approximately one third of the studied patients have GCK or HNF1A mutations. Inclusion criteria included efficiency in detecting patients with GCK mutations but not for HNF1A mutations (< 20%). MPC was helpful in narrowing the number of candidates for HNF1A screening.

MODY probability calculator for GCK and HNF1A screening in a multiethnic background population.

Objective We aimed to identify the frequency of monogenic diabetes, which is poorly studied in multiethnic populations, due to GCK or HNF1A mutations in patients with suggestive clinical characteristics from the Brazilian population, as well as investigate if the MODY probability calculator (MPC) could help patients with their selection. Subjects and methods Inclusion criteria were patients with DM diagnosed before 35 years; body mass index < 30 kg/m2; negative autoantibodies; and family history of DM in two or more generations. We sequenced HNF1A in 27 patients and GCK in seven subjects with asymptomatic mild fasting hyperglycemia. In addition, we calculated MODY probability with MPC. Results We identified 11 mutations in 34 patients (32.3%). We found three novel mutations. In the GCK group, six cases had mutations (85.7%), and their MODY probability on MPC was higher than 50%. In the HNF1A group, five of 27 individuals had mutations (18.5%). The MPC was higher than 75% in 11 subjects (including all five cases with HNF1A mutations). Conclusion Approximately one third of the studied patients have GCK or HNF1A mutations. Inclusion criteria included efficiency in detecting patients with GCK mutations but not for HNF1A mutations (< 20%). MPC was helpful in narrowing the number of candidates for HNF1A screening.

The first case of NEUROD1-MODY reported in Latin America.

BACKGROUND: MODY-NEUROD1 is a rare form of monogenic diabetes caused by mutations in Neuronal differentiation 1 (NEUROD1). Until now, only a few cases of MODY-NEUROD1 have been reported worldwide and the real contribution of mutations in NEUROD1 in monogenic diabetes and its clinical impact remain unclear. METHODS: Genomic DNA was isolated from peripheral blood lymphocytes of 25 unrelated Brazilians patients with clinical characteristics suggestive of monogenic diabetes and the screening of the entire coding region of NEUROD1 was performed by Sanger sequencing. RESULTS: We identified one novel frameshift deletion (p.Phe256Leufs*2) in NEUROD1 segregating in an autosomal dominant inheritance fashion. Almost 20 years after the first report of NEUROD1-MODY, only a few families in Europe and Asia had shown mutations in NEUROD1 as the cause of monogenic diabetes. CONCLUSION: To our knowledge, we described the first case of NEUROD1-MODY in a Latin American family.

Adrenal ganglioneuroma.

Adrenal incidentalomas (AI) are unsuspected adrenal masses discovered during investigation of unrelated diseases, and are increasing in frequency. The majority of the AI is non-secretory adenomas, although it can also represent primary or metastatic malignant neoplasia. However, less frequent diseases should not be forgotten in the differential diagnosis. We describe a case of a young woman with an adrenal mass without clinical or laboratorial signs of hormonal hyperfunction. Diagnosis was performed after an episode of acute pyelonephritis in which the imaging study was carried out in order to exclude local complications. During the surgical procedure, the fish flesh aspect of the mass raised the suspicion of a neurogenic tumor, which was diagnosed in the histophatological analysis. The patient presented the most common manifestation of adrenal ganglioneuroma, an incidentaloma.

Adrenal ganglioneuroma / Ganglioneuroma de adrenal

Adrenal incidentalomas (AI) are unsuspected adrenal masses discovered during investigation of unrelated diseases, and are increasing in frequency. The majority of the AI is non-secretory adenomas, although it can also represent primary or metastatic malignant neoplasia. However, less frequent diseases should not be forgotten in the differential diagnosis. We describe a case of a young woman with an adrenal mass without clinical or laboratorial signs of hormonal hyperfunction. Diagnosis was performed after an episode of acute pyelonephritis in which the imaging study was carried out in order to exclude local complications. During the surgical procedure, the fish flesh aspect of the mass raised the suspicion of a neurogenic tumor, which was diagnosed in the histophatological analysis. The patient presented the most common manifestation of adrenal ganglioneuroma, an incidentaloma.

Incidentalomas adrenais (IA) são massas descobertas ao acaso na investigação de distúrbios não relacionados a patologias das glândulas adrenais e tem se tornado cada vez mais frequentes. A maioria dos casos é constituída por adenomas não secretores, embora possa também representar uma neoplasia maligna primária ou metastática. Porém, no diagnóstico diferencial, doenças menos prevalentes não podem ser esquecidas. Relatamos um caso de massa adrenal em mulher jovem, sem sinais de hiperfunção clínica ou laboratorial. O diagnóstico foi feito após episódio de pielonefrite aguda, em que o exame de imagem foi realizado para excluir complicações locais. Durante a abordagem cirúrgica, o aspecto em carne de peixe da lesão fez suscitar a hipótese de uma lesão de origem neural, a qual foi prontamente definida pelo exame histopatológico. A paciente se apresentava com a manifestação mais comum do ganglioneuroma de adrenal, um incidentaloma.