Differential expression profiles of circulating microRNAs in newborns associated to maternal pregestational overweight and obesity.

BACKGROUND: The perinatal environment has a role in the establishment of altered metabolic and inflammatory responses, and could be modulated by microRNAs regulating immune and metabolic processes. OBJECTIVE: To analyze the expression profile of four circulating microRNAs and cytokine serum concentrations in neonates born to overweight and obese women. METHODS: Pregnant women were included and grouped by pregestational body mass index (21 with normal weight, 10 overweight and 10 obese women). A peripheral blood sample was obtained from newborn infants and used to determine circulating miRNAs expression and cytokine serum concentrations. RESULTS: There were significant differences in the expression of three microRNAs between newborns of pregestational obese women and newborns from pregestational normal weight women: miR-155 (p = 0.03), miR-181a (p = 0.02) and miR-221 (p = 0.04). A significant reduction in IL-1ß (p = 0.005) expression was also found in newborns of overweight women; although this cytokine was also diminished in newborns of obese women, this was not statistically significant. An association between IL-1ß concentrations and miR-146a and miR-221 expression was also observed. CONCLUSIONS: Expression of miR-155, miR-181a and miR-221 differs in infants born to obese women compared with infants born to normal weight women. Changes in microRNA expression could participate in the epigenetic foetal programming of metabolic disorders in children born to obese women.

Induction of transcription factors, miRNAs and cytokines involved in T lymphocyte differentiation in BCG-vaccinated subjects.

The BCG vaccine induces a Th1 phenotype, which is essential for protection against Mycobacterium tuberculosis. However, the effects of BCG vaccination over time on the T helper subpopulation and the microRNAs involved in adulthood have not been studied. In the present study, we explored the involvement of microRNAs, transcription factors and multifunctional cytokines in BCG vaccination by examining their levels both before and after vaccination of healthy adults. Peripheral blood mononuclear cells were obtained at 0, 2 and 6 months after vaccination. Cells were cultured in the presence or absence of ESAT-6 and CFP-10 or M. tuberculosis filtrate. The expression levels of miRNAs and transcription factors were evaluated using qRT-PCR. Cytokine production in supernatants and serum samples was evaluated using ELISA. Multifunctional CD4+ T cells were analyzed using multiparametric flow cytometry. We observed a decrease in the expression levels of T-BET, GATA3 and FOXP3 at 2 months and miR-146a, miR-326 and miR-155 at 6 months after receiving the vaccine. In the supernatant, the production of IL-17 was increased after 6 months, with both stimuli. In contrast, IL-10, TNF-α and IFN-γ increased at 2 months. In the serum, high levels of IL-10 were found after 2 months compared to time 0 and 6 months. The production of multifunctional cells that expressed the cytokine profiles CD4+TNF-α+IFN-γ-IL-10-, CD4+TNF-α+IL-1IFN-γ-, CD4+IL-10+IFN-γ-TNF-α- and CD4+IL-17+IFN-γ- predominantly increased after 2 months with and without the stimulus. Correlation analysis revealed a negative association between FOXP3 and miR-155 (r=-0.5120, p=0.0176) and between IL-17 and miR-326 (r=-0.5832, p=0.0364). This study is the first to demonstrate roles for microRNAs, transcription factors and cytokines in the T helper differentiation lineage and to describe the possible mechanism by which their expression is modulated by the presence of the BCG vaccine in adulthood. In conclusion, our results suggest that the BCG vaccine induces a modulation in transcription factors and miRNAs with high production of multifunctional cells CD4+TNF-α+IL-10+IFN-γ-.

Interferon regulatory factor 3 as key element of the interferon signature in plasmacytoid dendritic cells from systemic lupus erythematosus patients: novel genetic associations in the Mexican mestizo population.

Many genetic studies have found an association between interferon regulatory factors (IRF) single nucleotide polymorphisms (SNPs) and systemic lupus erythematosus (SLE); however, specific dendritic cell (DC) alterations have not been assessed. The aim of the present study was to address the expression of IRF3 and IRF5 on different DC subsets from SLE patients, as well as their association with interferon (IFN)-α production and novel SNPs. For the genetic association analyses, 156 SLE patients and 272 healthy controls from the Mexican mestizo population were included. From these, 36 patients and 36 controls were included for functional analysis. Two IRF3 SNPs - rs2304206 and rs2304204 - were determined. We found an increased percentage of circulating pDC in SLE patients in comparison to controls (8.04 ± 1.48 versus 3.35 ± 0.8, P = 0.032). We also observed enhanced expression of IRF3 (64 ± 6.36 versus 36.1 ± 5.57, P = 0.004) and IRF5 (40 ± 5.25 versus 22.5 ± 2.6%, P = 0.010) restricted to this circulating pDC subset from SLE patients versus healthy controls. This finding was associated with higher IFN-α serum levels in SLE (160.2 ± 21 versus 106.1 ± 14 pg/ml, P = 0.036). Moreover, the IRF3 rs2304206 polymorphism was associated with increased susceptibility to SLE [odds ratio (OR), 95% confidence interval (CI) = 2.401 (1.187-4.858), P = 0.021] as well as enhanced levels of serum type I IFN in SLE patients who were positive for dsDNA autoantibodies. The IRF3 rs2304204 GG and AG genotypes conferred decreased risk for SLE. Our findings suggest that the predominant IRF3 expression on circulating pDC is a key element for the increased IFN-α activation based on the interplay between the rs2304206 gene variant and the presence of dsDNA autoantibodies in Mexican mestizo SLE patients.

Arsenic and fluoride co-exposure affects the expression of apoptotic and inflammatory genes and proteins in mononuclear cells from children.

Humans may be exposed to arsenic (As) and fluoride (F) through water consumption. However, the interaction between these two elements and gene expression in apoptosis or inflammatory processes in children has not been thoroughly investigated. Herein, the expression of cIAP-1, XIAP, TNF-α, ENA-78, survivin, CD25, and CD40 was evaluated by RT-PCR. Additionally, the surface expression of CD25, CD40, and CD40L on peripheral blood mononuclear cells was analyzed by flow cytometry, and TNF-α was measured by Western blotting. This study examined 72 children aged 6-12 years who were chronically exposed to As (154.2µg/L) and F (5.3mg/L) in drinking water and in food cooked with the same water. The urine concentrations of As (6.9-122.4µg/L) were positively correlated with the urine concentrations of F (1.0-8.8mg/L) (r(2)=0.413, p<0.0001). The CD25 gene expression levels and urine concentrations of As and F were negatively correlated, though the CD40 expression levels were negatively correlated only with the As concentration. Age and height influenced the expression of cIAP-1, whereas XIAP expression was correlated only with age. Additionally, there was a lower percentage of CD25- and CD40-positive cells in the group of 6- to 8-year-old children exposed to the highest concentrations of both As and F when compared to the 9- to 12-year-old group (CD25: 0.7±0.8 vs. 1.1±0.9, p<0.0014; CD40: 16.0±7.0 vs. 21.8±5.8, p<0.0003). PHA-stimulated lymphocytes did not show any changes in the induction of CD25, CD69, or CD95. In summary, high concentrations of As and F alter the expression patterns of CD25 and CD40 at both the genetic and protein levels. These changes could decrease immune responses in children exposed to As and F.

Dysregulated miR-155 expression in peripheral blood mononuclear cells from patients with type 2 diabetes.

MicroRNAs (miRNAs) are involved in gene regulation of several physiological processes. Alterations in the concentrations of miRNAs may result in cancer and autoimmune diseases. In cells of the immune system, miRNA expression is regulated by several cytokines and this expression is related to the inflammatory process. In the present work we evaluated miR-155 and miR-146a levels in peripheral blood mononuclear cells (PBMC) from patients with type 2 diabetes (T2D).We analysed the expression of miRNAs in PBMC from T2D patients (n=20) and control subjects (n=20) using real-time PCR. The quantity of IL-1ß and IL-6 in culture supernatants was measured by ELISA.The basal expression of miR-155 and miR-146a in patients with T2D was decreased compared to control subjects and associated with age, gender and metabolic control but not with the therapeutic treatment used. We found significant correlations between the basal expression of miR-155 and miR-146a with HbA1c, Glucose and BMI, as well as of miR-155 expression stimulated by LPS with the values of TG, HbA1c, Glucose and BMI. Additionally, we detected an altered distribution of miR-155 and miR-146a expression related with HbA1c, glucose and BMI using the analysis of a three dimensional association of variables in the group of T2D patients.Downregulated levels of miR-155 could play an important role in the pathogenesis of T2D due to their relationship with metabolic control.

Human papillomavirus immunization is associated with increased expression of different innate immune regulatory receptors.

Human papillomavirus (HPV) is able to inhibit the secretion of gamma interferon (IFN-γ) and the expression of some immune innate cell receptors. Immunoglobulin-like transcript 2 (ILT2) is a regulatory receptor that seems to participate in the pathogenesis of viral infections. We have studied the expression and function of ILT2 and the expression of other NK cell receptors in 23 healthy women before and after immunization with the quadrivalent HPV (type 6/11/16/18) vaccine (Gardasil). Receptor expression was analyzed by flow cytometry in freshly isolated peripheral blood mononuclear cells as well as after in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine. In addition, the regulatory function of ILT2 on cell proliferation and IFN-γ production was analyzed. We found a significant increase in the expression of ILT2 by NK and CD3(+) CD56(+) lymphocytes and monocytes after quadrivalent HPV (type 6/11/16/18) vaccine immunization. In addition, the in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine also increased the proportion of CD3(-) CD56(+) ILT2(+) NK cells. Although the inhibitory function of ILT2 on cell proliferation was enhanced after HPV immunization, the in vitro engagement of this receptor did not affect the synthesis of IFN-γ induced by HPV. Finally, a significant increase in the expression of NKG2D, NKp30, and NKp46 by NK and CD3(+) CD56(+) lymphocytes was detected after quadrivalent HPV (type 6/11/16/18) vaccine immunization. Our data indicate that HPV immunization is associated with significant changes in the expression and function of different innate immune receptors, including ILT2, which may participate in the protective effect of HPV vaccines.

Exposure to indoor air pollutants (polycyclic aromatic hydrocarbons, toluene, benzene) in Mexican indigenous women.

UNLABELLED: Indoor air pollution is considered to be a serious public health issue in Mexico; therefore, more studies regarding this topic are necessary. In this context, we assessed exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds in: (i) women who use firewood combustion (indoor) for cooking and heating using traditional open fire; (ii) women who use firewood combustion (outdoor) for cooking and heating using traditional open fire; and (iii) women who use LP gas as the principal energy source. We studied 96 healthy women in San Luis Potosi, México. Urine samples were collected, and analyses of the following urinary exposure biomarkers were performed by high-performance liquid chromatography: 1-hydroxypyrene (1-OHP), trans, trans-muconic acid, and hippuric acid (HA). The highest levels of 1-OHP, trans, trans-muconic acid, and HA were found in communities where women were exposed to indoor biomass combustion smoke (or products; geometric mean ± s.d., 3.98 ± 5.10 µmol/mol creatinine; 4.81 ± 9.60 µg/l 1-OHP; 0.87 ± 1.78 mg/g creatinine for trans, trans-muconic acid; and 1.14 ± 0.91 g/g creatinine for HA). Our findings indicate higher exposure levels to all urinary exposure biomarkers studied in women who use indoor firewood combustion for cooking and heating (using traditional open fire). PRACTICAL IMPLICATIONS: High mean levels of 1-hydroxypyrene, t,t-muconic acid, and hippuric acid were found in women who use firewood combustion (indoor) for cooking and heating using traditional open fire and taking into account that millions of women and children in Mexico are living in scenarios similar to those studied in this report, the assessment of health effects in women and children exposed to polycyclic aromatic hydrocarbons and volatile organic compounds is urgently needed. Moreover, it is immediately necessary an intervention program to reduce exposure.

Regulatory T Cells in children with intestinal parasite infection.

Chronic intestinal parasite infection can induce both persistent immune activation and defective responsiveness of T cells. This study aimed to assess the number and function of T regulatory (Treg) cells in children with intestinal parasite infection. We have studied the peripheral blood from 93 children, 53 of them parasitized with protozoa, helminths, or both; the remainder were non parasitized, healthy controls. The number and function of CD4(+) CD25(high) and CD4(+) Foxp3(+) cells were similar in parasitized and control children. In contrast, there was a significant increase in the levels of CD3(+) CD69(+), CD4(+) CTLA-4(+), and CD8(+) CD28(-) T cells in helminth infected children. Moreover, some of these patients showed a diminished response to CD3/CD28 stimulation in comparison with the control children. Our data strongly suggest that whilst Treg cells are not affected by intestinal parasite infection, CD3(+) CD69(+), CD4(+) CTLA-4(+) and CD8(+) CD28(-) lymphocytes may play an important, but as yet undetermined role in the diminished immune competence observed in parasitized children.

Effect of arsenic on regulatory T cells.

INTRODUCTION: Arsenic (As) affects the function and survival of lymphocytes, and some arsenic compounds exert a relevant antineoplastic effect. We have explored the effect of As on T regulatory cells. RESULTS AND DISCUSSION: In vitro experiments with peripheral blood mononuclear cells from healthy subjects showed that low concentrations of As tended to increase the number of natural T regulatory (nTreg) lymphocytes, whereas concentrations >5.0 muM had an opposite effect. Furthermore, rats exposed to As showed redistribution of nTreg cells, and As administration to rats with experimental allergic encephalomyelitis increased the levels of nTreg cells in spleen and diminished the severity of this condition. On the other hand, in 47 apparently healthy subjects chronically exposed to As, we found significant inverse correlation between urinary As levels and the number and function of nTreg lymphocytes. Although most of these individuals showed enhanced levels of apoptotic lymphocytes in peripheral blood, with a diminution of mitochondrial membrane potential, no significant correlation between these parameters and urinary As was detected. CONCLUSION: Our data indicate that As seems to have a relevant and complex effect on nTreg cells.