Omega-3-Supplemented Fat Diet Drives Immune Metabolic Response in Visceral Adipose Tissue by Modulating Gut Microbiota in a Mouse Model of Obesity.

Obesity is a chronic, relapsing, and multifactorial disease characterized by excessive accumulation of adipose tissue (AT), and is associated with inflammation mainly in white adipose tissue (WAT) and an increase in pro-inflammatory M1 macrophages and other immune cells. This milieu favors the secretion of cytokines and adipokines, contributing to AT dysfunction (ATD) and metabolic dysregulation. Numerous articles link specific changes in the gut microbiota (GM) to the development of obesity and its associated disorders, highlighting the role of diet, particularly fatty acid composition, in modulating the taxonomic profile. The aim of this study was to analyze the effect of a medium-fat-content diet (11%) supplemented with omega-3 fatty acids (D2) on the development of obesity, and on the composition of the GM compared with a control diet with a low fat content (4%) (D1) over a 6-month period. The effect of omega-3 supplementation on metabolic parameters and the modulation of the immunological microenvironment in visceral adipose tissue (VAT) was also evaluated. Six-weeks-old mice were adapted for two weeks and then divided into two groups of eight mice each: a control group D1 and the experimental group D2. Their body weight was recorded at 0, 4, 12, and 24 weeks post-differential feeding and stool samples were simultaneously collected to determine the GM composition. Four mice per group were sacrificed on week 24 and their VAT was taken to determine the immune cells phenotypes (M1 or M2 macrophages) and inflammatory biomarkers. Blood samples were used to determine the glucose, total LDL and HDL cholesterol LDL, HDL and total cholesterol, triglycerides, liver enzymes, leptin, and adiponectin. Body weight measurement showed significant differences at 4 (D1 = 32.0 ± 2.0 g vs. D2 = 36.2 ± 4.5 g, p-value = 0.0339), 12 (D1 = 35.7 ± 4.1 g vs. D2 = 45.3 ± 4.9 g, p-value = 0.0009), and 24 weeks (D1 = 37.5 ± 4.7 g vs. D2 = 47.9 ± 4.7, p-value = 0.0009). The effects of diet on the GM composition changed over time: in the first 12 weeks, α and ß diversity differed considerably according to diet and weight increase. In contrast, at 24 weeks, the composition, although still different between groups D1 and D2, showed changes compared with previous samples, suggesting the beneficial effects of omega-3 fatty acids in D2. With regard to metabolic analysis, the results did not reveal relevant changes in biomarkers in accordance with AT studies showing an anti-inflammatory environment and conserved structure and function, which is in contrast to reported findings for pathogenic obesity. In conclusion, the results suggest that the constant and sustained administration of omega-3 fatty acids induced specific changes in GM composition, mainly with increases in Lactobacillus and Ligilactobacillus species, which, in turn, modulated the immune metabolic response of AT in this mouse model of obesity.

Efectividad de la metformina en pacientes con diabetes tipo II según variantes en el gen SLC22A1 / Effectiveness of Metformin in patients with type II diabetes related to variants in the SLC22A1 gene / Eficácia de Metformina em doentes com diabetes tipo II, relacionado com variantes do gene SLC22A1

La diabetes mellitus tipo II (DM II) es una enfermedad que afecta una gran cantidad de individuos. Un medicamento empleado en el tratamiento de los pacientes es la metformina. Este medicamento es transportado al interior de los hepatocitos por un transportador codificado por el gen SLC22A1. Variantes en el gen con actividad reducida pueden disminuir la cantidad de metformina disponible en el hígado y reducir la respuesta terapéutica. Se propuso evaluar diferentes parámetros bioquímicos en relación a la dosis de metformina y la presencia de variantes en el transportador. Se estudiaron 103 pacientes mayores de 18 años con diagnóstico de DM II, tratados con 1700 mg/día de metformina por más de 6 meses. Se analizaron 5 polimorfismos en el gen SLC22A1, glucemia, HbA1c, función hepática, perfil lipídico y renal. Los niveles de HbA1c y de glucemia fueron más elevados en los pacientes que presentaban los polimorfismos R61C, G401S, M420del y G465R aunque la diferencia fue estadísticamente significativa sólo para la HbA1c en los pacientes que presentaban las variantes M420del y G465R (p=0,0273 y 0,0018, respectivamente). La presencia de polimorfismos con actividad reducida en el gen SLC22A1 afecta los niveles de glucemia y de HbA1c en pacientes con DM II cuando son tratados con metformina.

Diabetes mellitus type II (DM II) is a disease that affects a large number of individuals. One of the drugs used for the treatment is metformin. Metformin is delivered into hepatocytes by a transporter encoded by the SLC22A1 gene. Gene variants with reduced activity may decrease the amount of metformin available in the liver and reduce the therapeutic response. Various biochemical parameters were evaluated in relation to the metformin dose and the presence of transporter variants. A total of 103 patients older than 18 diagnosed with DM II who were treated with 1700 mg/day of metformin for more than six months were studied. Five polymorphisms in the SLC22A1 gene were analyzed as well as glycemia, HbA1c level, liver function, and lipid and kidney profiles. HbA1c and glycemia levels were higher in patients with the R61C, G401S, M420del and G465R polymorphisms; although the difference was statistically significant only for HbA1c in patients with the M420del and G465R variants (p=0.0273 and 0.0018, respectively). Polymorphisms with reduced activity in the SLC22A1 gene affect blood glucose levels and HbA1c in patients with DM II when they are treated with metformin.

O diabetes mellitus tipo II (DM II) é uma doença que afeta uma grande quantidade de indivíduos. Um medicamento utilizado no tratamento dos doentes é a metformina. Esse medicamento é transportado no interior dos hepatócitos por um transportador codificado pelo gene SLC22A1. Variantes no gene com atividade reduzida podem diminuir a quantidade de Metformina disponível no fígado e reduzir a resposta terapêutica. Propôs-se avaliar diferentes parâmetros bioquímicos em relação à dose da metformina e à presença de variantes no transportador. Foram estudados 103 pacientes maiores de 18 anos com diagnóstico de DM II tratados com 1700 mg/dia de metformina por mais de 6 meses. Foram analisados 5 polimorfismos no gene SLC22A1; glicemia, HbA1c, função hepática, perfil lipídico e renal. Os níveis de HbA1c e de glicemia foram superiores em doentes que apresentavam os polimorfismos R61C, G401S, M420del e G465R; embora a diferença seja estatisticamente significativa apenas para o HbA1c nos doentes que apresentavam as variantes M420del e G465R (p=0,0273 e 0,0018; respectivamente). A presença de polimorfismos com atividade reduzida no gene SLC22A1 afeta os níveis da glicemia e do HbA1c em doentes com DM II quando são tratados com metformina.

Efectividad de la metformina en pacientes con diabetes tipo II según variantes en el gen SLC22A1 / Effectiveness of Metformin in patients with type II diabetes related to variants in the SLC22A1 gene / Eficácia de Metformina em doentes com diabetes tipo II, relacionado com variantes do gene SLC22A1

La diabetes mellitus tipo II (DM II) es una enfermedad que afecta una gran cantidad de individuos. Un medicamento empleado en el tratamiento de los pacientes es la metformina. Este medicamento es transportado al interior de los hepatocitos por un transportador codificado por el gen SLC22A1. Variantes en el gen con actividad reducida pueden disminuir la cantidad de metformina disponible en el hígado y reducir la respuesta terapéutica. Se propuso evaluar diferentes parámetros bioquímicos en relación a la dosis de metformina y la presencia de variantes en el transportador. Se estudiaron 103 pacientes mayores de 18 años con diagnóstico de DM II, tratados con 1700 mg/día de metformina por más de 6 meses. Se analizaron 5 polimorfismos en el gen SLC22A1, glucemia, HbA1c, función hepática, perfil lipídico y renal. Los niveles de HbA1c y de glucemia fueron más elevados en los pacientes que presentaban los polimorfismos R61C, G401S, M420del y G465R aunque la diferencia fue estadísticamente significativa sólo para la HbA1c en los pacientes que presentaban las variantes M420del y G465R (p=0,0273 y 0,0018, respectivamente). La presencia de polimorfismos con actividad reducida en el gen SLC22A1 afecta los niveles de glucemia y de HbA1c en pacientes con DM II cuando son tratados con metformina.(AU)

Diabetes mellitus type II (DM II) is a disease that affects a large number of individuals. One of the drugs used for the treatment is metformin. Metformin is delivered into hepatocytes by a transporter encoded by the SLC22A1 gene. Gene variants with reduced activity may decrease the amount of metformin available in the liver and reduce the therapeutic response. Various biochemical parameters were evaluated in relation to the metformin dose and the presence of transporter variants. A total of 103 patients older than 18 diagnosed with DM II who were treated with 1700 mg/day of metformin for more than six months were studied. Five polymorphisms in the SLC22A1 gene were analyzed as well as glycemia, HbA1c level, liver function, and lipid and kidney profiles. HbA1c and glycemia levels were higher in patients with the R61C, G401S, M420del and G465R polymorphisms; although the difference was statistically significant only for HbA1c in patients with the M420del and G465R variants (p=0.0273 and 0.0018, respectively). Polymorphisms with reduced activity in the SLC22A1 gene affect blood glucose levels and HbA1c in patients with DM II when they are treated with metformin.(AU)

O diabetes mellitus tipo II (DM II) é uma doenþa que afeta uma grande quantidade de indivíduos. Um medicamento utilizado no tratamento dos doentes é a metformina. Esse medicamento é transportado no interior dos hepatócitos por um transportador codificado pelo gene SLC22A1. Variantes no gene com atividade reduzida podem diminuir a quantidade de Metformina disponível no fígado e reduzir a resposta terapÛutica. Prop¶s-se avaliar diferentes parÔmetros bioquímicos em relaþÒo O dose da metformina e O presenþa de variantes no transportador. Foram estudados 103 pacientes maiores de 18 anos com diagnóstico de DM II tratados com 1700 mg/dia de metformina por mais de 6 meses. Foram analisados 5 polimorfismos no gene SLC22A1; glicemia, HbA1c, funþÒo hepática, perfil lipídico e renal. Os níveis de HbA1c e de glicemia foram superiores em doentes que apresentavam os polimorfismos R61C, G401S, M420del e G465R; embora a diferenþa seja estatisticamente significativa apenas para o HbA1c nos doentes que apresentavam as variantes M420del e G465R (p=0,0273 e 0,0018; respectivamente). A presenþa de polimorfismos com atividade reduzida no gene SLC22A1 afeta os níveis da glicemia e do HbA1c em doentes com DM II quando sÒo tratados com metformina.(AU)

Distribution of polymorphisms in cytochrome P450 2B6, histocompatibility complex P5, chemokine coreceptor 5, and interleukin 28B genes in inhabitants from the central area of Argentina.

AIMS: The selection of the most appropriate treatment for several diseases relies on a number of factors such as environment, age, gender, and nutrition. Additionally, the contribution of different genetic polymorphisms to treatment efficacy has been largely recognized. The lack of information on the pharmacogenetic profile of our population prompted us to analyze the frequency of polymorphisms known to be relevant to achieve treatment efficacy with different therapeutic agents in viral infectious diseases, such as Hepatitis C and AIDS. RESULTS: The allelic frequencies for the wild-type variant of the genes analyzed were cytochrome P450 2B6 (CYP2B6; rs3745274; 516G) 0.618 (95% confidence interval [CI]: 0.523, 0.711), chemokine coreceptor 5 (CCR5; rs333) 0.961 (95% CI: 0.942, 0.98), histocompatibility complex P5 (HCP5; rs2395029; 335T) 0.971 (95% CI: 0.937, 1), and interleukin 28B (IL28B; rs12979860; 12007005C) 0.656 (95% CI: 0.564, 0.747), respectively. CONCLUSIONS: Our data indicate that the genetic profile of the population studied is similar to that reported for other Caucasian populations, with only slight differences for CYP2B6. Noteworthy, the considerable number of patients carrying CYP2B6 (516T) and IL28B (12007005T) alleles underlies the importance of considering pharmacogenetic testing before starting drug therapy protocols to prevent toxicity and/or lack of effectiveness in AIDS or hepatitis C virus infections.

Genetic profiling of GSTP1, DPYD, FCGR2A, FCGR3A and CCND1 genes in an Argentinian population.

OBJECTIVES: To determine the frequencies of relevant allelic variants in oncology for the GSTP1, DPYD, FCGR2A, FCGR3A and CCND1 genes in a population from Central Argentina. To compare the allelic distribution found with the frequencies reported for other ethnic groups. DESIGN AND METHODS: Genotyping was carried out in a total of 102 unrelated Argentinian subjects. FCGR3A (rs396991) was detected using allele specific polymerase chain reaction (PCR) assay, while GSTP1 (rs1695), DPYD (rs3918290), FCGR2A (rs1801274) and CCND1 (rs9344) variants were assessed by PCR-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The allele frequencies for GSTP*1B, DPYD*2A, FCGR2A (131R), FCGR3A (158F) and CCND1 (870G) in Argentinians were 0.35, 0.005, 0.41, 0.77 and 0.47, respectively. CONCLUSIONS: We found that the Argentinian population tested resembles other Caucasians populations, especially Spaniards; yet the differences in allele distribution with other Caucasian groups, uncover population admixture with native Amerindian and other ethnic groups, consistent with the well documented immigration flows landing Argentina from several countries.

Development of a method to control the RNA extraction and reverse transcription steps for the detection of dengue virus present in human blood samples.

AIMS: Molecular biology techniques based on the detection of genomic sequences by reverse transcription combined with polymerase chain reaction (PCR) have enabled the detection of different RNA viruses in serum or plasma samples. Since the dengue epidemic outbreak declared in Argentina in 2009, numerous patients' samples were analyzed for the acute phase of infection. One of the main methodological drawbacks is the lack of internal control to measure the effectiveness of the viral extraction and reverse transcription process. In this article, we propose to standardize a molecular method to detect beta actin (ß-Act) and glucose 6 phosphate dehydrogenase (G6PDH) complementary DNAs (cDNAs) present in patient's plasma/serum, as a control process. RESULTS: RNA extraction, reverse transcription, and PCRs for human G6PDH, ß-Act, and the dengue virus genome were performed. cDNA fragments for ß-Act and G6PDH were amplified for all samples, regardless of the presence or absence of viral RNA. CONCLUSIONS: Amplification of ß-Act and G6PDH cDNAs can be used as a control for the extraction and reverse transcription processes during dengue virus detection. This could also be a useful method for controlling the above steps when infections caused by other RNA viruses are studied, even if another methodology is employed, such as real-time PCR.

Rapid HCP5 single-nucleotide polymorphism genotyping: a simple allele-specific PCR method for prediction of hypersensitivity reaction to Abacavir.

BACKGROUND: The most important factor limiting the success of an antiretroviral therapy is toxicity. The HLA-B*5701 allele is predictive of hypersensitivity reaction to Abacavir, and this gene is in a perfect linkage disequilibrium with the rs2395029 SNP present in the HCP5 gene. METHODS: Genomic DNA was extracted from blood obtained from 201 unrelated healthy Argentinean volunteers. The DNA was subjected to an allele-specific PCR method. Sequencing was performed to validate the test results. RESULTS: We were successful to amplify specific fragment of interest from the DNA samples. The method is easy, specific and reproducible. CONCLUSIONS: The application of this methodology is a rapid and simple method to detect the HCP5 polymorphism (rs2395029) previous to administration of Abacavir in patients with HIV infection.

A simple allele-specific polymerase chain reaction method to detect the Gly143Glu polymorphism in the human carboxylesterase 1 gene: importance of genotyping for pharmacogenetic treatment.

Human carboxylesterases 1 and 2 (CES1 and CES2) catalyze the hydrolysis of many exogenous compounds. Alterations in CES sequences could lead to variability in both the inactivation of drugs and the activation of prodrugs. The human CES1 gene encodes for the enzyme carboxylesterase 1, a serine esterase governing both metabolic deactivation and activation of numerous therapeutic agents. Some of theses drugs are the antiviral oseltamivir used to treat some types of influenza infections and the methylphenidate employed in the treatment of patients with attention deficit. The Gly143Glu polymorphism in CES1 gene has been shown to reduce enzyme activity. The aim of the present study was to develop an easy and cheap method to detect this polymorphism. For this, we studied a group of people from Córdoba, a Mediterranean area from Argentina. Our results show that our methodology could detect the presence of this polymorphism with a frequency around 1.8%, only in the heterozygote form. These results could be relevant to patients before the treatment with some drugs where the CES1 enzyme is involved.

Anomalous surface distribution of glycosyl phosphatidyl inositol-anchored proteins in neurons lacking acid sphingomyelinase.

Acid sphingomyelinase (ASM) converts sphingomyelin (SM) into ceramide. Mutations in the ASM gene cause the mental retardation syndrome Niemann Pick type A (NPA), characterized as a lysosomal disorder because of the SM accumulation in these organelles. We here report that neurons from mice lacking ASM (ASMKO) present increased plasma membrane SM levels evident in detergent-resistant membranes. Paralleling this lipidic alteration, GPI-anchored proteins show an aberrant distribution in both axons and dendrites instead of the axonal enrichment observed in neurons from wild-type mice. Trafficking analysis suggests that this is due to defective internalization from dendrites. Increasing the SM content in wild-type neurons mimics these defects, whereas SM reduction in ASMKO neurons prevents their occurrence. Moreover, expression of active RhoA, which membrane attachment is affected by SM accumulation, rescues internalization rates in ASMKO neurons. These data unveil an unexpected role for ASM in neuronal plasma membrane organization and trafficking providing insight on the molecular mechanisms involved. They also suggest that deficiencies in such processes could be key pathological events in NPA disease.

Proper axonal distribution of PrP(C) depends on cholesterol-sphingomyelin-enriched membrane domains and is developmentally regulated in hippocampal neurons.

Defects in cellular localization and trafficking seem to facilitate the conversion of PrP(C) into the disease-associated form, PrP(Sc). Still, it is not clear to which membrane compartments PrP(C) localizes in hippocampal neurons a population most affected in the prion disease. We here show that in developing hippocampal neurons in culture PrP(C) is equally distributed to all neurites yet enriched in growth cones. By contrast, in fully mature neurons PrP(C) is restricted to axons. The axonal distribution in mature stages is paralleled by the increased partitioning of PrP(C) into detergent-resistant cholesterol-sphingolipid-rich domains (DRMs). Consistent with a cause-effect mechanism, disruption of DRMs by sphingolipid or cholesterol depletion leads to the non-polarized distribution and impaired endocytosis of PrP(C). These results indicate that DRMs are essential for proper trafficking and distribution of PrP(C) at late stages of neuronal differentiation and that its function, at least in hippocampus, is restricted to the axonal domain.

Plasmin deficiency in Alzheimer's disease brains: causal or casual?

Substantial recent evidence suggests that defects in amyloid peptide degradation can be at the base of cases of sporadic Alzheimer's disease (AD). Among the discovered brain enzymes with the capacity to degrade amyloid peptide, the serine protease plasmin acquires special physiological relevance because of its low levels in areas of AD human brains with a high susceptibility to amyloid plaque accumulation. In this article we comment on a series of observations supporting the fact that plasmin paucity in the brain is not simply a secondary event in the disease but rather a primary defect in certain cases of sporadic AD. We also refer to recent data pointing to alterations in raft membrane domains and diminished membrane cholesterol as the underlying cause. Finally, we discuss the possibility that plasmin deficiency in the brain could lead to AD symptomatology because of amyloid aggregation and the triggering of cell death signaling cascades.

Raft disorganization leads to reduced plasmin activity in Alzheimer's disease brains.

The serine protease plasmin can efficiently degrade amyloid peptide in vitro, and is found at low levels in the hippocampus of patients with Alzheimer's disease (AD). The cause of such paucity remains unknown. We show here that the levels of total brain plasminogen and plasminogen-binding molecules are normal in these brain samples, yet plasminogen membrane binding is greatly reduced. Biochemical analysis reveals that the membranes of these brains have a mild, still significant, cholesterol reduction compared to age-matched controls, and anomalous raft microdomains. This was reflected by the loss of raft-enriched proteins, including plasminogen-binding and -activating molecules. Using hippocampal neurons in culture, we demonstrate that removal of a similar amount of membrane cholesterol is sufficient to induce raft disorganization, leading to reduced plasminogen membrane binding and low plasmin activity. These results suggest that brain raft alterations may contribute to AD by rendering the plasminogen system inefficient.

Astrocytic but not neuronal increased expression and redistribution of parkin during unfolded protein stress.

Parkin is a ubiquitin ligase that facilitates proteasomal protein degradation and is involved in a common autosomal recessive form of Parkinson's disease. Its expression is part of the unfolded protein response in cell lines where its overexpression protects against unfolded protein stress. How parkin expression is regulated in brain primary cells under stress situations is however, less well established. Here, the cellular and subcellular localization of parkin under basal conditions and during unfolded protein stress was investigated in primary cultures of rat astrocytes and hippocampal neurons. Immunofluorescense microscopy and biochemical analysis demonstrated that parkin is mainly associated with the endoplasmic reticulum (ER) in hippocampal neurons while it is associated with Golgi membranes, the nuclei and light vesicles in astrocytes. The constitutive parkin expression was high in neurons as compared with astrocytes. However, unfolded protein stress elicited a selective increase in astrocytic parkin expression and a change in distribution, whereas neuronal parkin remained largely unmodified. The cell specific differences argue in favour of different cellular binding sites and substrates for the protein and a pathogenic role for astrocytes in Parkinson's disease caused by parkin dysfunction.