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INTRODUCTION: The metabolic syndrome (MetS) is a cluster of abnormalities related to cardiovascular disease (CVD). Circulating miRNAs (c-miRNAs) are non-coding RNAs associated with different phenotypes, some of them integrating the MetS. The aim of the study was to compare the c-miRNAs profile in plasma between women with MetS and controls and explore their possible association with dysregulation of metabolic pathways. METHODS: The study was conducted in two phases. At the screening phase, miRNA composition in fasting plasma was compared between 8 participants with MetS and 10 healthy controls, using microarray technology. The validation phase included the analysis by qRT-PCR of 10 selected c-miRNAs in an independent sample (n = 29). RESULTS: We found 21 c-miRNAs differentially expressed between cases and controls. The concentration in plasma of the c-miRNAs hsa-miR-1260a, hsa-miR-4514, and hsa-miR-4687-5p were also correlated with risk factors for CVD. Differences of hsa-miR-1260a between cases and controls were validated using qRT-PCR (fold-change = 7.0; p = 0.003). CONCLUSION: The signature of plasma c-miRNAs differed between women with MetS and controls. The identified miRNAs regulate pathways related to the MetS such as insulin resistance and adipokine activity. The role of c-miR-1260a in the MetS remains to be elucidated.

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Our group built a genetic risk score (GRS) of the plasma triglyceride (TG) response to an omega-3 (n-3) fatty acid (FA) supplementation in Caucasian Canadians that explained 21.53% of the TG variance. The objective was to refine the GRS by fine mapping and to test its association with the TG response in young Mexican adults. A total of 191 participants underwent a 6-week n-3 FA supplementation providing 2.7g/day of docosahexaenoic and eicosapentaenoic acids. Using quantitative polymerase chain reaction (PCR), 103 single-nucleotide polymorphisms (SNPs) were genotyped. A stepwise regression adjusted for age, sex, and body mass index (BMI) was used to select the strongest SNPs to include in the genetic risk model. A GRS was calculated from the sum of at-risk alleles. The contribution of the GRS to the TG response was assessed by ANCOVA with age, sex, and BMI included in the model. Several differences in allele frequency were observed between Canadians and Mexicans. Five lead SNPs were included in the genetic risk model, in which the GRS accounted for 11.01% of the variance of the TG response (p < 0.0001). These findings highlight the important contribution of genetic factors to the heterogeneity of the TG response to an n-3 FA supplementation among Mexicans.

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BACKGROUND: Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. RESULTS: RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. CONCLUSIONS: RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.

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BACKGROUND: Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. RESULTS: RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. CONCLUSIONS: RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.

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BACKGROUND/AIM: Genetic variation in apolipoprotein E (ApoE) has a key role in lipid metabolism. However, its contribution to the amount and distribution of body fat is under investigation. The aim of this study was to analyze the association between genetic variation in ApoE and obesity-related traits in Mexican school children. MATERIAL AND METHODS: Anthropometric, body composition and physical activity measures were conducted using standard methods in 300 children (177 girls/123 boys) who fulfilled the inclusion criteria. DNA was isolated from saliva. ApoE genotypes were analyzed by allelic discrimination. The association between variation in ApoE and anthropometric and body composition measures was investigated using the General Linear Model. RESULTS: The mean±SD values for age, body mass index (BMI) and waist circumference (WC) were 9.05±0.80 years, 19.01±3.83 and 67.98±10.97 cm, respectively. Approximately 46% of the participants were overweight or obese. A significant association between ApoE isoforms and WC was found after controlling for age, sex and the percentage of physical activity (p=0.025). Significant main effects were found for vigorous physical activity and light physical activity influencing the adiposity-related BMI (p<0.001) and WC (p=0.044), respectively. CONCLUSIONS: Variation in ApoE and physical activity intensity were associated with adiposity-related phenotypes in Mexican school children.

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BACKGROUND: In 2002 Takamatsu and co-workers described the human DSCR9 gene and observed that it was transcriptionally active in human testicular tissue, but no protein was identified as a product of this transcript. Similar results were obtained in chimpanzee tissue. This gene has not been detected in species other than primates, suggesting that DSCR9 is exclusively found in these mammals. RESULTS: We report evidence of DSCR9 expression in placenta, testis and kidney of baboon (Papio hamadryas). We used primers specific for DSCR9 to amplify transcripts through reverse transcription (RT) coupled to polymerase chain reaction (PCR). Furthermore, PCR was used to amplify the complete DSCR9 gene from genomic DNA from three baboons. We amplified and sequenced five overlapping segments that were assembled into the 3284 bp baboon DSCR9 gene, including the putative promoter and the entire transcriptional unit (5'-UTR, CDS and 3'-UTR). CONCLUSIONS: The baboon DSCR9 gene is highly similar to the human counterpart. The isolated transcripts from baboon tissues (placenta, testis and kidney) of three different baboons correspond to the human orthologous gene.

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La obesidad es la acumulación excesiva de tejido adiposo, consecuencia del desequilibrio energético. Los cambios en la disponibilidad y características de los alimentos y en la actividad física en las últimas décadas han dado lugar a que la ingestión de energía exceda al gasto. Esta tendencia se observa en todos los grupos de edad y en numerosos países. La respuesta a estos cambios ambientales que afectan a la dieta y actividad física es variada, y ciertos individuos y poblaciones parecen tener mayor predisposición al desarrollo de la obesidad y de sus comorbilidades. En la obesidad, en etapas tempranas de la vida, es importante diferenciar la obesidad ocasionada por anormalidades genéticas de aquellas formas comunes. Numerosas alteraciones genéticas se caracterizan por la obesidad. En algunos casos mutaciones en un solo gen, pueden tener un efecto importante sobre el índice de masa corporal (IMC). Este manuscrito presenta los aspectos genéticos de formas poco frecuentes y comunes de obesidad, con especial interés en la población infantil. También presenta diferentes abordajes metodológicos empleados en investigaciones sobre la genética de la obesidad y la variación en el IMC, incluyendo estudios de asociación de genes candidatos, barrido del genoma, asociación del genoma y estudios de perfil transcripcional. Actualmente, la obesidad se considera una enfermedad compleja con bagaje poligénico. Algunos alelos han sido asociados a la obesidad común y el IMC; sin embargo, los efectos observados son modestos y se requieren replicaciones en diferentes poblaciones para confirmar el efecto de estas variantes y establecer los mecanismos que explican su contribución a la obesidad.

Obesity is the excessive deposition of adipose tissue resulting of energy imbalance. The changes in food availability and characteristics, as well as the decrease in physical activity during the last decades have favored the energy imbalance causing that energy intake exceeds energy expenditure. This trend has been observed in all age groups across different countries. The response to environmental changes affecting diet and physical activity is widely diverse and certain subjects and populations seem to be more prone to develop obesity and its related comorbidities. In early onset obesity it is important to differentiate between obesity due to rare genetic abnormalities from the common forms. Numerous genetic abnormalities are characterized by obesity. In some cases, single gene mutations can have a very important effect on body mass index (BMI). The present manuscript addresses the rare and common forms of obesity with special regard to observations in children. It also discusses different methodological approaches currently used for the study of genetic factors influencing common obesity or variation in BMI, including the candidate gene approach, genome scan, genome-wide association studies and gene expression studies. Nowadays obesity is considered a complex disease with a polygenic background. Some gene variants have been associated with common obesity and variation in BMI. However, the effects observed seem to be minor and replications in different populations are required to confirm the effect of the identified alleles and to establish the mechanisms that explain their contribution to obesity.