Phenotype similarities in automatically grouped T2D patients by variation-based clustering of IL-1ß gene expression.

Background: Analyzing longitudinal gene expression data is extremely challenging due to limited prior information, high dimensionality, and heterogeneity. Similar difficulties arise in research of multifactorial diseases such as Type 2 Diabetes. Clustering methods can be applied to automatically group similar observations. Common clinical values within the resulting groups suggest potential associations. However, applying traditional clustering methods to gene expression over time fails to capture variations in the response. Therefore, shape-based clustering could be applied to identify patient groups by gene expression variation in a large time metabolic compensatory intervention. Objectives: To search for clinical grouping patterns between subjects that showed similar structure in the variation of IL-1ß gene expression over time. Methods: A new approach for shape-based clustering by IL-1ß expression behavior was applied to a real longitudinal database of Type 2 Diabetes patients. In order to capture correctly variations in the response, we applied traditional clustering methods to slopes between measurements. Results: In this setting, the application of K-Medoids using the Manhattan distance yielded the best results for the corresponding database. Among the resulting groups, one of the clusters presented significant differences in many key clinical values regarding the metabolic syndrome in comparison to the rest of the data. Conclusions: The proposed method can be used to group patients according to variation patterns in gene expression (or other applications) and thus, provide clinical insights even when there is no previous knowledge on the subject clinical profile and few timepoints for each individual.

Guía práctica para la solicitud de marcadores humorales de autoinmunidad y estudios genéticos en diabetes mellitus / A practical guide to request humoral autoimmunity markers and genetic tests in diabetes mellitus

La diabetes mellitus (DM) es una enfermedad heterogénea que presenta fenotipos clínicos diversos, todos con hiperglucemia. Históricamente se han utilizado cuatro factores para identificar esta diversidad: la edad de inicio, la gravedad de la enfermedad o grado de pérdida de la función de la célula beta, el grado de resistencia a la insulina y la presencia de autoanticuerpos asociados a la enfermedad. Actualmente, los parámetros empleados para clasificar los diferentes tipos de DM dificultan el diagnóstico y tratamiento de los pacientes. Las distintas presentaciones clínicas requieren una clasificación diagnóstica más eficaz para un abordaje terapéutico más preciso, valiéndose del avance de la inmunogenética y la bioquímica clínica. Esta guía está orientada a clasificar con precisión las presentaciones clínicas que a menudo generan incertidumbre dentro de los dos tipos principales de DM.

Diabetes mellitus (DM) is a heterogeneous disease, with diverse clinical phenotypes, all with hyperglycemia. Historically, four factors have been used to identify this diversity: the age at onset, the severity of the disease, that is, the degree of loss of beta cell function and insulin resistance, and the presence of circulating autoantibodies. Currently, the parameters used to classify the different types of DM make it difficult to diagnose and treat patients. The different clinical manifestations require an accurate diagnosis to achieve an effective therapeutic approach through the use of immunogenetics and clinical biochemistry. This practical guide aims to accurately classify the often uncertain clinical presentations within the two main types of diabetes.

Guía práctica para la solicitud de marcadores humorales de autoinmunidad y estudios genéticos en diabetes mellitus / A practical guide to request humoral autoimmunity markers and genetic tests in diabetes mellitus

Resumen La diabetes mellitus (DM) es una enfermedad heterogénea que presenta fenotipos clínicos diversos, todos con hiperglucemia. Históricamente se han utilizado cuatro factores para identificar esta diversidad: la edad de inicio, la gravedad de la enfermedad o grado de pérdida de la función de la célula beta, el grado de resistencia a la insulina y la presencia de autoanticuerpos asociados a la enfermedad. Actualmente, los parámetros empleados para clasificar los diferentes tipos de DM dificultan el diagnóstico y tratamiento de los pacientes. Las distintas presentaciones clínicas requieren una clasificación diagnóstica más eficaz para un abordaje terapéutico más preciso, valiéndose del avance de la inmunogenética y la bioquímica clínica. Esta guía está orientada a clasificar con precisión las presentaciones clínicas que a menudo generan incertidumbre dentro de los dos tipos principales de DM.

Abstract Diabetes mellitus (DM) is a heterogeneous disease, with diverse clinical phenotypes, all with hyperglycemia. Historically, four factors have been used to identify this diversity: the age at onset, the severity of the disease, that is, the degree of loss of beta cell function and insulin resistance, and the presence of circulating autoantibodies. Currently, the parameters used to classify the different types of DM make it difficult to diagnose and treat patients. The different clinical manifestations require an accurate diagnosis to achieve an effective therapeutic approach through the use of immunogenetics and clinical biochemistry. This practical guide aims to accurately classify the often uncertain clinical presentations within the two main types of diabetes.

Telomere Length Differently Associated to Obesity and Hyperandrogenism in Women With Polycystic Ovary Syndrome.

Background: Polycystic Ovary Syndrome (PCOS) often present metabolic disorders and hyperandrogenism (HA), facts that may influence the telomere length (TL). Aims: To compare the absolute TL (aTL) between women with PCOS and control women, and their association with the presence of obesity and HA parameters. Materials and methods: The PCOS group included 170 unrelated women outpatients and the control group, 64 unrelated donor women. Anthropometric, biochemical-clinical parameters and androgen profile were determined. The PCOS patients were divided accordingly to the presence of obesity and androgenic condition. The aTL was determined from peripheral blood leukocytes by Real Time quantitative PCR. Results: Women with PCOS exhibited a significantly longer aTL than controls after age adjustment (p=0.001). A stepwise multivariate linear regression in PCOS women, showed that WC (waist circumference) contributed negatively (b=-0.17) while testosterone levels contributed positively (b=7.24) to aTL. The non-Obese PCOS (noOB-PCOS) presented the longest aTL when compared to controls (p=0.001). Meanwhile, the aTL was significantly higher in the hyperandrogenic PCOS phenotype (HA-PCOS) than in the controls (p=0.001) and non hyperandrogenic PCOS phenotype (NHA-PCOS) (p=0.04). Interestingly, when considering obesity and HA parameters in PCOS, HA exerts the major effect over the aTL as non-obese HA exhibited the lengthiest aTL (23.9 ± 13.13 Kbp). Conversely, the obese NHA patients showed the shortest aTL (16.5 ± 10.59 Kbp). Conclusions: Whilst a shorter aTL could be related to the presence of obesity, a longer aTL would be associated with HA phenotype. These findings suggest a balance between the effect produced by the different metabolic and hormonal components, in PCOS women.

Relationship between the IL-1ß serum concentration, mRNA levels and rs16944 genotype in the hyperglycemic normalization of T2D patients.

To evaluate Interleukin 1-beta (IL-1ß) serum and mononuclear leucocyte mRNA levels, also rs16944 (-511C/T) genotype, in relation to hyperglycemic normalization in Type 2 diabetes (T2D) patients, we recruited 30 individuals recently T2D diagnosed with hyperglycemia studied at basal time and after 6 and 12 months of the normalization treatment. At basal time, the T polymorphic allele of the rs16944 was associated with lower IL-1ß mRNA expression (p = 0.006); and higher glucose level was positive correlated to IL-1ß protein levels (p = 0.015). After treatment, the individuals showed a significant decrease in glucose level (p = 0.003), but they did not express significant changes in the IL-1ß serum levels. Surprisingly, we observed that the greater decreases in glucose level were associated to increased IL-1ß serum levels (p = 0.040). This is the first follow-up study evaluating IL-1ß mRNA expression and serum levels in hyperglycemic T2D individuals and after glycemic normalization treatment. The current results contribute to the knowledge of the relationship between inflammation and glucose metabolism in T2D.

Getting to Know the Gut Microbial Diversity of Metropolitan Buenos Aires Inhabitants.

In recent years, the field of immunology has been revolutionized by the growing understanding of the fundamental role of microbiota in the immune system function. The immune system has evolved to maintain a symbiotic relationship with these microbes. The aim of our study was to know in depth the uncharacterized metagenome of the Buenos Aires (BA) city population and its metropolitan area, being the second most populated agglomeration in the southern hemisphere. For this purpose, we evaluated 30 individuals (age: 35.23 ± 8.26 years and BMI: 23.91 ± 3.4 kg/m2), from the general population of BA. The hypervariable regions V3-V4 of the bacterial 16S gene was sequenced by MiSeq-Illumina system, obtaining 47526 ± 4718 sequences/sample. The dominant phyla were Bacteroidetes, Firmicutes, Proteobacteria, Verrucomicrobia, and Actinobacteria. Additionally, we compared the microbiota of BA with other westernized populations (Santiago de Chile, Rosario-Argentina, United States-Human-microbiome-project, Bologna-Italy) and the Hadza population of hunter-gatherers. The unweighted UniFrac clustered together all westernized populations, leaving the hunter-gatherer population from Hadza out. In particular, Santiago de Chile's population turns out to be the closest to BA's, principally due to the presence of Verrucomicrobiales of the genus Akkermansia. These microorganisms have been proposed as a hallmark of a healthy gut. Finally, westernized populations showed more abundant metabolism related KEEG pathways than hunter-gatherers, including carbohydrate metabolism (amino sugar and nucleotide sugar metabolism), amino acid metabolism (alanine, aspartate and glutamate metabolism), lipid metabolism, biosynthesis of secondary metabolites, and sulfur metabolism. These findings contribute to promote research and comparison of the microbiome in different human populations, in order to develop more efficient therapeutic strategies for the restoration of a healthy dialogue between host and environment.

Metabolically healthy obese individuals present similar chronic inflammation level but less insulin-resistance than obese individuals with metabolic syndrome.

The Metabolic Syndrome (MetS) is a cluster of cardiometabolic risk factors, usually accompanied by the presence of insulin resistance (IR) and a systemic subclinical inflammation state. Metabolically healthy obese (MHO) individuals seem to be protected against cardiometabolic complications. The aim of this work was to characterize phenotypically the low-grade inflammation and the IR in MHO individuals in comparison to obese individuals with MetS and control non obese. We studied two different populations: 940 individuals from the general population of Buenos Aires and 518 individuals from the general population of Venado Tuerto; grouped in three groups: metabolically healthy non-obese individuals (MHNO), MHO and obese individuals with MetS (MSO). Inflammation was measured by the levels of hs-CRP (high-sensitivity C reactive protein), and we found that MHO presented an increase in inflammation when compared with MHNO (Buenos Aires: p<0.001; Venado Tuerto: p<0.001), but they did not differ from MSO. To evaluate IR we analyzed the HOMA (Homoeostatic Model Assessment) values, and we found differences between MHO and MSO (Buenos Aires: p<0.001; Venado Tuerto: p<0.001), but not between MHNO and MHO. In conclusion, MHO group would be defined as a subgroup of obese individuals with an intermediate phenotype between MHNO and MSO individuals considering HOMA, hs-CRP and central obesity.

Presentaciones poco frecuentes de diabetes tipo MODY: el ejemplo de MODY tipo 5 y las formas de novo de MODY tipo 2 / Infrequent presentations of MODY diabetes: the example of MODY type 5 and de novo forms of MODY type 2

La diabetes tipo MODY se produce por alteraciones en genes relacionados con el metabolismo de la célula beta pancreática. El tipo 2 es uno de los más frecuentes y se produce por alteraciones en el gen GCK (glucoquinasa) y el tipo 5 es mucho menos frecuente y se produce por alteraciones en el gen HNF1B (factor nuclear hepático 1B). Se presentan con herencia autosómica dominante, aunque se ha descripto la presencia de mutaciones de novo. El objetivo del trabajo fue buscar mutaciones en el gen GCK en pacientes sin antecedentes familiares pero con características clínicas de MODY2 y mutaciones en el gen HNF1B en pacientes con características clínicas de MODY5 con y sin antecedentes familiares. Para ello a partir de ADN se realizó la secuenciación de cada gen por el método de Sanger o por secuenciación de nueva generación. Como resultado, se hallaron mutaciones en el gen GCK en cuatro pacientes sin antecedentes familiares y mutaciones en el gen del HNF1B en dos pacientes, uno de ellos sin antecedentes familiares. Como conclusión puede afirmarse que las mutaciones de novo en el gen de la GCK son más frecuentes de lo descripto, por lo cual se recomienda el estudio del gen en pacientes con características compatibles aún sin antecedentes familiares. También es importante el estudio del gen HNF1B en pacientes con características típicas ya que deben tratarse no sólo por sus alteraciones renales sino por la diabetes presente; de esta manera se logra un correcto diagnóstico para instaurar el tratamiento más adecuado

Analysis of mutations in the glucokinase gene in people clinically characterized as MODY2 without a family history of diabetes.

BACKGROUND: Maturity-onset diabetes of the young 2 (MODY2) is a form of diabetes that is clinically characterized by early age at onset and mild hyperglycemia, and has a low risk of late complications. It is often underdiagnosed due to its mild symptoms. To date, over 600 different GCK/MODY2 mutations have been reported. Despite only a few de novo mutations having been described, recent studies have reported the detection of a higher frequency of this kind of mutation. Therefore, de novo mutations could be more frequent than previously described. Even though common recommendations regarding the diagnosis of monogenic diabetes include the existence of a strong family history of diabetes, here we describe the study of mutations in two families with a symptomatic individual with clear clinical features of MODY2 but without any family history of diabetes. METHODS: Genetic diagnosis in a group of participants with MODY2 characteristics was carried out by direct sequencing of coding regions of the GCK gene and analysis of mutations found using bioinformatics tools. RESULTS: We found two de novo mutations, one of them novel, constituting 14.29% of all the participants who were phenotyped as MODY2. CONCLUSIONS: The number of mutations in GCK/MODY2 or even other MODY-related genes is undoubtedly underestimated, as accepted criteria for performing genetic tests include family history of the pathology. These cases illustrate the value of analyzing the GCK gene in patients with clinical features of MODY2, even in the absence of family history of the condition as it is essential for establishing the correct treatment.

Análisis de la longitud de los telómeros en obesos metabólicamente sanos / Analysis of telomere length in the metabolically healthy obese

La obesidad es el principal componente del síndrome metabólico (SM) y determina la progresión de la enfermedad a las complicaciones metabólicas. Los individuos obesos metabólicamente sanos (OMS) parecen estar protegidos contra esas complicaciones. La longitud de los telómeros (LT) es un nuevo marcador del envejecimiento celular, que tiene una relación compleja con el SM. El objetivo principal de este estudio fue investigar por primera vez la LT en OMS y estudiar la asociación entre LT y el número de componentes del SM. Se estudió a 398 mujeres con una edad media de 46,76 ± 15,47 años (rango: 18-86 años), que se agruparon en: individuos con normopeso sin ningún componente del SM (NP0), obesos sin SM (OMS) y de acuerdo con el número de componentes de SM en los grupos sin ningún componentes de SM (0), con uno o 2 componentes (1 + 2) y con SM por la presencia de 3 o más componentes (SM). La LT de los OMS no se diferenció de la de los NP0, pero fue significativamente mayor que la de los individuos con SM (p = 0,032). Se observó una disminución de la LT con el aumento progresivo del número de componentes del SM (p = 0,004), en donde el grupo 0 presentó una LT significativamente mayor que los grupos 1 + 2 (p = 0,027) y SM (p = 0,003). Demostramos por primera vez que las mujeres OMS presentan una LT similar a las mujeres NP0 y más larga que aquellas mujeres con SM. Además, confirmamos que la LT se acorta con el aumento en el número de alteraciones del SM.

Obesity is the principal component in Metabolic Syndrome (MetS) and determines the progression of metabolic complications. Metabolically healthy obese individuals (MHO) seem to be protected against those complications. Telomere length (TL), as a novel marker of cellular aging, has a complex relationship with MetS. The principal aim of this study was to investigate TL in MHO, and to study the association between TL and the number of MetS components. A study was conducted on 398 women (mean age: 46.76 ± 15.47 years; range: 18 - 86 years), grouped according to the number of MetS components (0, 1 + 2, MetS), a group of normal-weight individuals with 0 MetS components (NW0), and a group of obese without MetS (MHO). No differences were found in the TL of the MHO group compared to the NW0, but it was significantly higher than that of individuals with MetS (P = .032). A decrease in TL was observed with a progressive increase in the number of MetS components (P = .004), whereas the group of individuals without MetS components had significantly longer TL than the groups with 1 and 2 components (P = .027), and MetS (P = .003). Shorter TL is not associated with MHO, but is related to MetS and with an increased number of metabolic abnormalities.

Functional characterization of TLR4 +3725 G/C polymorphism and association with protection against overweight.

Subclinical low-grade systemic inflammation has been associated with obesity, insulin resistance and metabolic syndrome (MS). Recent studies have highlighted the role of gut microbiota in these disorders. The toll-like receptor 4 (TLR4) plays a key role in the innate immune response activation. We studied two polymorphisms (+3725G/C and 11350G/C) in the 3' untranslated region (3'UTR) of the TLR4 gene that may alter its expression and their association with metabolic disorders related to systemic inflammation. We cloned the 3'UTR into a luciferase reporter system and compared wild-type 3'UTR (WT) and +3725C variant (MUT) constructs luciferase activities. MUT construct reduced the reporter gene activity by 30% compared to WT (P = 0.0001). To evaluate the association between these polymorphisms with biochemical and clinical overweight related variables, we conducted a population cross-sectional study in 966 men of Argentine general population. Considering smoking as a confounding variable that causes systemic inflammation, we studied these possible effects in both, smokers and nonsmokers. The 11350G/C polymorphism was not detected in our sample whereas the CC genotype of +3725 polymorphism was associated with lean subjects (p = 0.011) and higher Adiponectin levels (p = 0.021). Subjects without any NCEP/ATP III MS component were associated with this genotype as well (p = 0.001). These results were strengthened in nonsmokers, in which CC genotype was associated with lean subjects (p = 0.003) and compared with G carriers showed significantly lower BMI (25.53 vs. 28.60 kg/m2; p = 0.023) and waist circumference (89.27 vs. 97.51 cm; p = 0.025). None of these associations were found in smokers. These results showed that +3725C variant has a functional effect down-regulating gene expression and it could be considered as a predictive factor against overweight, particularly in nonsmokers. Considering the role of TLR4 in inflammation, these findings would suggest that the presence of +3725C variant could predict a lower prevalence of chronic metabolic disorders.

HNF1 alpha gene coding regions mutations screening, in a Caucasian population clinically characterized as MODY from Argentina.

INTRODUCTION: There are at least six subtypes of Maturity Onset Diabetes of the Young (MODY) with distinctive genetic causes. MODY 3 is caused by mutations in HNF1A gene, an insulin transcription factor, so mutations in this gene are associated with impaired insulin secretion. MODY 3 prevalence differs according to the population analyzed, but it is one of the most frequent subtypes. Therefore, our aims in this work were to find mutations present in the HNF1A gene and provide information on their prevalence. MATERIAL AND METHODS: Mutations screening was done in a group of 80 unrelated patients (average age 17.1 years) selected by clinical characterization of MODY, by SSCP electrophoresis followed by sequenciation. RESULTS: We found eight mutations, of which six were novel and four sequence variants, which were all novel. Therefore the prevalence of MODY 3 in this group was 10%. Compared clinical data between the non-MODY 3 patients and the MODY 3 diagnosed patients did not show any significant difference. DISCUSSION: Eight patients were diagnosed as MODY 3 and new data about the prevalence of that subtype is provided. Our results contribute to reveal novel mutations, providing new data about the prevalence of that subtype.

Cytotoxic T lymphocyte antigen 4 heterozygous codon 49 A/G dimorphism is associated to latent autoimmune diabetes in adults (LADA).

Autoimmune diabetes is an organ specific and multifactorial disorder with a classical onset as insulin dependent diabetes mellitus (IDDM) and with another form of onset as latent autoimmune diabetes in adults (LADA), which has a slower onset and a later progress to insulin dependency as a result of the beta cells destruction. The cytotoxic T lymphocyte-antigen 4 (CTLA4) has been identified as a susceptible marker of the disease; it is considered a down regulator of T cell function, playing a key role in autoimmunity. We analyzed CTLA4 codon 49 A/G polymorphism in 123 IDDM patients, 63 LADA patients and 168 healthy non-diabetic control individuals. The frequency of the heterozygous A/G genotype in LADA patients was significantly increased compared to IDDM patients (55.6 vs. 39.8%, p = 0.0415). There was no statistical significant difference in the distribution of the A/G dimorphism between autoimmune diabetes patients (LADA or IDDM) and non-diabetic control individuals. HLA DQ region is responsible for the genetic susceptibility to autoimmune diabetes in IDDM patients in about 50% and it has a lower effect in genetic susceptibility in LADA patients. Several other genetic loci are needed to develop autoimmune diabetes in adult patients. Therefore, LADA may be the result of a combined minor risk loci effect in a major risk haplotype.

Variable number of tandem repeats of the insulin gene determines susceptibility to latent autoimmune diabetes in adults.

BACKGROUND: The different clinical presentations of latent autoimmune diabetes in adults (LADA) and type 1 diabetes mellitus may be the result of susceptibility genes in determining the mode of onset. We analyzed the 5' polymorphisms of the insulin mini-satellite region (INS), a variable number of tandem repeats (VNTR) [repeat units; RU]. We evaluated the association of the different INS-VNTR alleles in patient susceptibility to LADA autoimmune diabetes. To our knowledge, this constitutes the first study of this kind performed in a Caucasian population. METHODS: From an group of 160 Argentinean patients previously characterized as having LADA, we selected 44 patients who presented with humoral autoimmunity for genotyping and compared them to 88 patients with type 1 diabetes and 138 healthy individuals. The INS-VNTR allele classes were determined by Southern blotting (class I: 21-44RU; class III: 138-159RU). Subjects with class I alleles were further studied using PCR amplification to determine the exact length of the alleles (short 1S: 22-37RU; medium 1M: 38-41RU; large 1L: 42-43RU). Allelic and genotype frequencies were estimated by chi(2) tests for independence with 2 x 2 contingency tables and the relative risks (RR) were determined using GraphPad InStat software. RESULTS: We observed differential associations among the class I alleles when comparing patients with LADA (80.6%) and type 1 diabetes (81.3%) with the controls (70%; p < 0.005). This increase was largely due to the high frequency of the 1S/S genotype (63.6% LADA vs 37% controls, with a p-value of 0.0019 [p1]; 53.4% type 1 diabetes vs 37% controls, with a p-value of 0.0149 [p2]). Remarkably, all LADA patients genotyped as class I homozygous had the shorter (S) class I allele (100%). Differences in the overall 1S distribution were observed: in LADA the 94.4% of the alleles were equal to or smaller than 35RU, while in patients with type 1 diabetes it was 78.3% and in controls 74.1%. Moreover, the relative risks associated with the 1S/S genotype for patients with LADA showed a substantial increase with respect to those with type 1 diabetes (52%) when we compare them to the controls (1S/S LADA/control, 2.282 [RR1] vs type 1 diabetes/control, 1.497 [RR2]). CONCLUSION: The presence of the 1S allele could be considered a risk factor in LADA patients, as previously reported for type 1 diabetes. The class I INS-VNTR allele in LADA increases genetic susceptibility to disease development.

A novel mutation in exon 5 of the glucokinase gene in an Argentinian family with maturity onset diabetes of the young.

Maturity onset diabetes of the young (MODY) is caused by mutations in at least six different genes, including the glucokinase gene (MODY 2) and genes encoding the tissue-specific transcription factors (MODY 1 and MODY 3-6). To determine the presence of mutations in MODY 2 in four members of a family who have the clinical characteristics of MODY, we performed polymerase chain reaction and single strand conformation polymorphism screening, followed by DNA sequencing. We found a novel mutation which consisted of the deletion of a cytosine in the position 2 of the exon 5 codon 168. This mutation produced a frame shift which determines a stop codon at position 203 in exon 6. The identification of a mutation in glucokinase gene and transcription factor genes in patients with early-onset diabetes confirms the diagnosis of MODY and has important implications for clinical management.