Longitudinal large-scale changes in maternal circulating microRNAs associated with gestation-related compartments, fetal sex, and growth during and post-pregnancy.

Circulating microRNAs (c-miRNAs) during pregnancy could provide information regarding the functional status of the mother and fetus. However, it remains unclear which pregnancy-related processes are actually reflected by changes c-miRNAs. Here, we used large-scale c-miRNA profiling of maternal plasma during and post-pregnancy, and compared it with that of non-pregnant women. Fetal growth measurements and fetal sex data were used to identify associated changes in these transcripts. Surprisingly, c-miRNA subpopulations with prominent expression in maternal/fetal compartments (placenta, amniotic fluid, umbilical cord plasma and breast milk) were found to be under-expressed in circulation throughout pregnancy relative to non-pregnant plasma profiles. Furthermore, we found a bias in global c-miRNA expression in association with fetal sex right from the first trimester, in addition to a specific c-miRNA signature of fetal growth. Our results demonstrate the existence of specific temporal changes in c-miRNA populations associated with specific pregnancy-related compartments and processes, including fetal sex, and growth.

DNA Methylation Variability in a Single Locus of the RXRα Promoter from Umbilical Vein Blood at Term Pregnancy.

DNA methylation status of RXRα gene promoter has been correlated with maternal diet during early pregnancy, and associated with offspring's adiposity and bone mineral content. In adult life, increased methylation of RXRα promoter region is associated with myocardium pathologies. Early growth response proteins (EGR) are zinc finger transcription factors associated with several cellular pathways such as inflammation, apoptosis, and cardiopathies. DNA-binding sequences of EGR proteins have been reported in the RXRα gene promoter using chromatin immunoprecipitation methods. Here, we used correlations between the maternal pre-pregnancy body mass index (p-BMI), gestational weight gain (GWG), and birth weight (BW) as indirect indicators of the maternal nutritional status as modifier of DNA methylation in the offspring. DNA methylation status from newborns' umbilical vein blood in full-term pregnancy was evaluated in a short sequence (116 pb) of the RXRα gene promoter that contains the elements of response sequence for EGR proteins. Fifty-three bisulfite-modified DNA samples were assessed through methyl-sensitive high-resolution melting (MS-HRM) analysis. To validate the results, we directly sequenced MS-HRM samples to confirm the presence of CpG-methylated positions. In addition, the RXRα protein levels in extracts of umbilical vein blood were evaluated by western blot. We found differential methylation in a specific locus of the RXRα promoter surrounding the EGR-binding sequence; however, no correlation was found with the level of RXRα protein expression. Variability in the methylation status of the RXRα promoter near the EGR transcription factor binding site in newborn cord blood provides controversial epigenetic insights into RXRα regulation via EGR proteins.

Developmental programming-ageing effects in muscle strength of obese rat offspring in a sex-dependent manner.

Maternal obesity programs the offspring to metabolic dysfunction. However, the effects of maternal obesity on skeletal muscle programming and ageing have been little explored. To determine if maternal obesity is a detriment to the progress of age-related muscle strength loss in the offspring (F1), we evaluated the indicators of muscle strength, adiposity, and metabolism at young adult and senior adult ages of maternal obesity F1 (MOF1) males and females from a high-fat diet-induced maternal obesity model in rat. Controls were agematched siblings whose mothers were fed a standard maternal diet (CF1). Combinatorial data analysis was performed with body weight (BW), forelimb grip strength (FGS), FGS adjusted with BW, body fat, adiposity index, and serum triacylglycerols, cholesterol, glucose, insulin, and homeostatic model assessment for insulin resistance variables, to identify discriminant traits of variation among F1 groups. During ageing, maternal obesity caused glucose and cholesterol metabolic dysfunctions in male F1, whereas adiposity-associated skeletal strength loss and fatty acid alterations were present in female offspring. In conclusion, offspring programming-ageing effects due to maternal obesity impact metabolism and skeletal muscle strength loss at later ages in a sex-dependent manner.

Cervicovaginal Cytokines to Predict the Onset of Normal and Preterm Labor: a Pseudo-longitudinal Study.

Inflammatory processes associated with human parturition are still not completely understood, not only because the gap between inflammation and the onset of labor has been difficult to study but also because of the limited knowledge about the role of cervicovaginal fluid (CVF) cytokines during the sequence of labor. We aimed to determine whether CVF cytokines could predict the onset of normal and preterm labor. Chemokines and proinflammatory and anti-inflammatory cytokines in CVF were measured in a pseudo-longitudinal manner in healthy women between 12 and 41 weeks gestation with intact fetal membranes before and during the first stage of labor. Women were grouped into five stages, from the absence of uterine activity and cervical changes to regular uterine contractions with cervix dilation > 3 cm (active phase of labor). Of 144 women with spontaneous labor, 96 gave birth at term, 48 gave birth preterm, and both groups displayed similar cytokine concentrations. We found positive correlations between proinflammatory cytokines and the initial sequence of labor, using individual cytokines and score-based data by principal component analysis (IFN-γ, TNF-α, IL-1ß, IL-6) as dependent variables. The risk of labor onset increased as the concentrations of IL-6 increased (hazard ratio = 202.09, 95% confidence interval = 24.57-1662.49, P < 0.001). The IL-6 concentration predicted the onset of labor within 12 days of sampling (area under the time-dependent ROC curve = 0.785, 95% confidence interval = 0.693-0.877). Here, we showed that regardless of gestational age, the onset of labor could be predicted by the IL-6 concentration in the CVF, since the initial sequence of spontaneous labor displayed an inflammatory response expressed by the increase in proinflammatory cytokines.

Hyperglycemia induces early upregulation of the calcium sensor KChIP3/DREAM/calsenilin in the rat retina.

Hyperglycemia alters the tight control of intracellular calcium dynamics in retinal cells and may lead to the development of diabetic retinopathy. The potassium channel interacting protein 3 (KChIP3) also known as DREAM (Downstream Regulatory Element Antagonist Modulator) or calsenilin (KChIP3/DREAM/calsenilin), a member of the neuronal calcium sensor protein family, is expressed in Müller glial cells and upregulated under high glucose experimental culture conditions. Here, we analyzed the expression and function of KChIP3 in the retina of streptozotocin induced diabetic Long Evans rats by immunofluorescence confocal microscopy, western blot, co-immunoprecipitation, whole cell patch clamp recording on isolated cells and KChIP3 gene silencing by RNA interference. Three weeks after streptozotocin application, KChIP3 was increased throughout the different retinal layers and this process was not linked to augmented apoptosis. KChIP3 co-immunoprecipitated with voltage gated K(+) channels of the K(V)4.2-4.3 subtype in retinal extracts from control and hyperglycemic rats. Electrophysiological analysis showed that control cells did not express A type (K(V)4-mediated) K(+) currents but most of the cells from streptozotocin treated retinas displayed macroscopic currents with an inactivating component sensitive to 4-AP, suggesting the persistence of the A type currents at early times after treatment. siRNA analysis in Müller cells cultures grown under high glucose experimental conditions corroborated that, when the expression of KChIP3 is 50% reduced, the number of cells expressing A type currents decreases significantly. Together these data suggest an altered expression and function of KChIP3 after streptozotocin induced hyperglycemia that might help explain some pathological alterations in early diabetic retinopathy.

Sex-differential RXRα gene methylation effects on mRNA and protein expression in umbilical cord of the offspring rat exposed to maternal obesity.

Maternal obesity (MO) induces negative consequences in the offspring development. Adiposity phenotype is associated with maternal diet at early pregnancy and DNA methylation marks in the RXRα promotor at birth. Glucocorticoids play an important role in the regulation of metabolism through the activation of nuclear hormone receptors such as the RXRα protein. The aim of the study was to analyze steroid hormone changes at the end of pregnancy in the obese mother and RXRα gene methylation in the umbilical cord. For this purpose, in a well-established MO model, female Wistar rats were fed either standard chow (controls: C) or high-fat obesogenic diet (MO) before and during pregnancy to evaluate at 19 days of gestation (19 dG): 1) maternal concentration of circulating steroid hormones in MO and C groups, 2) maternal and fetal weights, 3) analysis of correlation between hormones concentration and maternal and fetal weights, 4) DNA methylation status of a single locus of RXRα gene near the early growth response (EGR-1) protein DNA binding site, and 5) RXRα mRNA and protein expressions in umbilical cords. Our results demonstrate that at 19 dG, MO body weight before and during pregnancy was higher than C; MO progesterone and corticosterone serum concentrations were higher and estradiol lower than C. There were not differences in fetal weight between male and female per group, therefore averaged data was used; MO fetal weight was lower than C. Positive correlations were found between progesterone and corticosterone with maternal weight, and estradiol with fetal weight, while negative correlation was observed between corticosterone and fetal weight. Additionally, male umbilical cords from MO were hypermethylated in RXRα gene compared to male C group, without differences in the female groups; mRNA and protein expression of RXRα were decreased in F1 male but not in female MO compared to C. In conclusion, MO results in dysregulation of circulating steroid hormones of the obese mothers and low fetal weight in the F1, modifying DNA methylation of RXRα gene as well as RXRα mRNA and protein expression in the umbilical cord in a sex-dependent manner.

Expression and high glucose-mediated regulation of K+ channel interacting protein 3 (KChIP3) and KV4 channels in retinal Müller glial cells.

Normal vision depends on the correct function of retinal neurons and glia and it is impaired in the course of diabetic retinopathy. Müller cells, the main glial cells of the retina, suffer morphological and functional alterations during diabetes participating in the pathological retinal dysfunction. Recently, we showed that Müller cells express the pleiotropic protein potassium channel interacting protein 3 (KChIP3), an integral component of the voltage-gated K(+) channels K(V)4. Here, we sought to analyze the role of KChIP3 in the molecular mechanisms underlying hyperglycemia-induced phenotypic changes in the glial elements of the retina. The expression and function of KChIp3 was analyzed in vitro in rat Müller primary cultures grown under control (5.6 mM) or high glucose (25 mM) (diabetic-like) conditions. We show the up-regulation of KChIP3 expression in Müller cell cultures under high glucose conditions and demonstrate a previously unknown interaction between the K(V)4 channel and KChIP3 in Müller cells. We show evidence for the expression of a 4-AP-sensitive transient outward voltage-gated K(+) current and an alteration in the inactivation of the macroscopic outward K(+) currents expressed in high glucose-cultured Müller cells. Our data support the notion that induction of KChIP3 and functional changes of K(V)4 channels in Müller cells could exert a physiological role in the onset of diabetic retinopathy.

Susceptibility for Some Infectious Diseases in Patients With Diabetes: The Key Role of Glycemia.

Uncontrolled diabetes results in several metabolic alterations including hyperglycemia. Indeed, several preclinical and clinical studies have suggested that this condition may induce susceptibility and the development of more aggressive infectious diseases, especially those caused by some bacteria (including Chlamydophila pneumoniae, Haemophilus influenzae, and Streptococcus pneumoniae, among others) and viruses [such as coronavirus 2 (CoV2), Influenza A virus, Hepatitis B, etc.]. Although the precise mechanisms that link glycemia to the exacerbated infections remain elusive, hyperglycemia is known to induce a wide array of changes in the immune system activity, including alterations in: (i) the microenvironment of immune cells (e.g., pH, blood viscosity and other biochemical parameters); (ii) the supply of energy to infectious bacteria; (iii) the inflammatory response; and (iv) oxidative stress as a result of bacterial proliferative metabolism. Consistent with this evidence, some bacterial infections are typical (and/or have a worse prognosis) in patients with hypercaloric diets and a stressful lifestyle (conditions that promote hyperglycemic episodes). On this basis, the present review is particularly focused on: (i) the role of diabetes in the development of some bacterial and viral infections by analyzing preclinical and clinical findings; (ii) discussing the possible mechanisms by which hyperglycemia may increase the susceptibility for developing infections; and (iii) further understanding the impact of hyperglycemia on the immune system.

Simultaneous evaluation of metabolomic and inflammatory biomarkers in children with different body mass index (BMI) and waist-to-height ratio (WHtR).

Metabolic disturbances and systemic pro-inflammatory changes have been reported in children with obesity. However, it is unclear the time-sequence of metabolic or inflammatory modifications during children obesity evolution. Our study aimed to quantify simultaneously metabolomic and inflammatory biomarkers in serum from children with different levels of adiposity. For this purpose, a cross-sectional study was used to perform targeted metabolomics and inflammatory cytokines measurements. Serum samples from children between six to ten years old were analyzed using either body mass index (BMI) or waist-to-height ratio (WHtR) classifications. One hundred and sixty-eight school-aged children were included. BMI classification in children with overweight or obesity showed altered concentrations of glucose and amino acids (glycine and tyrosine). Children classified by WHtR exhibited imbalances in amino acids (glycine, valine, and tyrosine) and lipids (triacyl glycerides and low-density lipoprotein) compared to control group. No differences in systemic inflammation biomarkers or in the prevalence of other results were found in these children. Abnormal arterial blood pressure was found in 32% of children with increased adiposity. In conclusion, obesity in school-aged children is characterized by significant metabolic modifications that are not accompanied by major disturbances in circulating concentrations of inflammatory biomarkers.

Influence of pre-pregnancy body mass index (p-BMI) and gestational weight gain (GWG) on DNA methylation and protein expression of obesogenic genes in umbilical vein.

Understanding the regulatory mechanisms that affect obesogenic genes expression in newborns is essential for early prevention efforts, but they remain unclear. Our study aimed to explore whether the maternal p-BMI and GWG were associated with regulatory single-locus DNA methylation in selected obesogenic genes. For this purpose, DNA methylation was assayed by Methylation-Sensitive High Resolution Melting (MS-HRM) technique and Sanger allele-bisulfite sequencing in fifty samples of umbilical vein to evaluate glucosamine-6-phosphate deaminase 2 (GNPDA2), peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α), and leptin receptor (LEPR) genes. Correlations between DNA methylation levels and indicators of maternal nutritional status were carried out. Western blotting was used to evaluate protein expression in extracts of the same samples. Results indicated that GNPDA2 and PGC1α genes have the same level of DNA methylation in all samples; however, a differential DNA methylation of LEPR gene promoter was found, correlating it with GWG and this correlation is unaffected by maternal age or unhealthy habits. Furthermore, leptin receptor (Lep-Rb) was upregulated in samples that showed the lowest levels of DNA methylation. This study highlights the association between poor GWG and adjustments on obesogenic genes expression in newborn tissues with potential consequences for development of obesity in the future.

D-Serine/N-methyl-D-aspartate receptor signaling decreases DNA-binding activity of the transcriptional repressor DREAM in Müller glia from the retina.

In the adult retina, N-methyl-D-aspartate (NMDA) neurotoxicity induces Müller cell reactive gliosis which is characterized by changes in gene expression that lead to proliferation and affect retinal physiology. The amino acid D-serine is synthesized in Müller cells and modulates these processes acting as a coagonist of NMDA receptors. We have found that the transcription factor DREAM (downstream regulatory element antagonist modulator), which acts as a transcriptional repressor by binding as a tetramer to regulatory elements located in the promoter region of target genes, is expressed in these cells and that its DNA-binding activity is modulated by NMDA receptor activation. Consistently, immunocytochemical analysis demonstrates that NMDA receptor activation induces changes in the nuclear localization of this transcription factor. DREAM is a pleiotropic transcription factor capable to repress and activate genes involved in several physiological events in different tissues. These results link, for the first time, this transcription factor with NMDA-receptor activation. Given the relevance of glutamatergic transmission in the retina and the remarkable functional plasticity of Müller cells, these findings support the notion that the NMDA receptor-dependent modulation of DREAM activity could play a role in relevant physiological processes ranging from retinal response to injury to differentiation capacity of retinal progenitor cells.

Development of Primer Pairs from Molecular Typing of Rabies Virus Variants Present in Mexico.

Nucleoprotein (N) gene from rabies virus (RABV) is a useful sequence target for variant studies. Several specific RABV variants have been characterized in different mammalian hosts such as skunk, dog, and bats by using anti-nucleocapsid monoclonal antibodies (MAbs) via indirect fluorescent antibody (IFA) test, a technique not available in many laboratories in Mexico. In the present study, a total of 158 sequences of N gene from RABV were used to design eight pairs of primers (four external and four internal primers), for typing four different RABV variants (dog, skunk, vampire bat, and nonhematophagous bat) which are most common in Mexico. The results indicate that the primer and the typing variant from the brain samples, submitted to nested and/or real-time PCR, are in agreement in all four singleplex reactions, and the designed primer pairs are an alternative for use in specific variant RABV typing.