Mother's smoking habits affects IL10 methylation but not asthma in Ecuadorian children.

There is no evidence evaluating the IL10 epigenetic upregulation among mestizo children in a high-altitude Andean city in Latin America. OBJECTIVE: To identify polymorphisms and methylation profiles in the IL10 gene associated with asthma in children aged 5 to 11. METHODS: A case-control study was conducted with asthmatic and non-asthmatic children aged 5 to 11 years in Cuenca-Ecuador. Data on allergic diseases and risk factors were collected through a questionnaire for parents. Atopy was measured by skin prick test (SPT) to relevant aeroallergens. Three IL10 single nucleotide polymorphisms were evaluated in all participants, and methylation analysis was performed in 54 participants. Association between risk factors, allergic diseases and genetic factors were estimated using multivariate logistic regression. RESULTS: The results of polymorphisms showed no differences between cases and controls when comparing the SNPs rs3024495, rs3024496, rs1800896 allelic and genotypic frequencies. In the methylation analysis, no differences in the IL10 methylation profile were found between cases and controls; however, the multivariate analysis showed an association between the mother's smoking habits and the IL10 methylation profile. CONCLUSION: Smoking habit could be essential as an environmental exposure factor in regulating gene expression in children with asthma.

Diagnostic evaluation of nCoV-QS, nCoV-QM-N, and nCoV-OM detection kits based on rRT-PCR for detection of SARS-CoV-2 in Ecuador.

Background: Ecuador was harshly impacted by COVID-19, in the region was the epicenter of the pandemic with the highest mortality rates and with the lowest rates of processed samples. Real-time reverse transcription PCR assays are essential to identify and manage the SARS-CoV-2 outbreak. Because of the global emergency, in Ecuador several commercial kits were introduced for use without clinical validation. In this manner, having the need to perform an evaluation with clinical samples before use for population screening. Objective: This study aimed to evaluate the diagnostic performance of the nCoV-QS, nCoV-QM-N, nCoV-OM detection kits lately available in Ecuador, against the LightMix E/RdRp kit using nasopharyngeal swab (NPS) samples. Materials and methods: 198 nasopharyngeal samples were used (66 fresh NPS and 132 RNA stored samples). All samples were analyzed for SARS-CoV-2 with nCoV-QS, nCoV-QM-N, nCoV-OM detection kits and compared the concordance (Cohen's Kappa index, positive percentage agreement and negative percentage agreement) to LightMix E/RdRp as reference detection kit. Results: The 198 samples presented strong concordance (96% nCoV-QM-N, 100% nCoV-OM and 100% nCoV-QS). The individual performance of each gene showed that the nCoV-OM kit had a higher number of samples detected with the ORF3a (52.5%) and N (53.5%) genes. The combined genes demonstrated that ORF3a/N of nCoV-OM and nCoV-QS kits presented a higher percentage of detection with 52.5% and 48.5%, respectively. Finally, the detection rate and cycle threshold were not different between ORF3a, N, and E target genes. Conclusion: The nCoV-QS, nCoV-QM-N, and nCoV-OM Detection kits have comparable diagnostic performance to the emergency approved LightMix E/RdRp kit for SARS-CoV-2 detection in suspected COVID-19 patients.

PPARGC1A promoter DNA-methylation level and glucose metabolism in Ecuadorian women with Turner syndrome.

OBJECTIVES: Reduced gene expression of PPARGC1A in subjects with insulin resistance (IR) has been reported. Insulin resistance occurs early on the course of Turner syndrome (TS). The main objective of this study was to evaluate the relationship between PPARGC1A promoter DNA methylation status in lymphocytes and insulin sensitivity and secretion in Ecuadorian females with TS. METHODS: We examined a cohort of 34 Ecuadorian patients with TS along with a sex-, age- and BMI-matched reference group. All subjects received a standard 75 g oral glucose tolerance test. Insulin resistance and secretion indices were calculated. The PPARGC1A methylated DNA/unmethylated DNA ratio and mitochondrial content (mtDNA/nDNA ratio) were further determined. RESULTS: Notably, the PPARGC1A DNA methylation level was significantly higher in TS subjects than the reference group and correlated with IR indices. Conversely, mitochondrial content was significantly lower in the study group than healthy controls and negatively correlated with the PPARGC1A methylated DNA/unmethylated DNA ratio in TS individuals. PPARGC1A promoter DNA methylation status contributed to 20% of the total variability in Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) independently of BMI or age in TS subjects. CONCLUSIONS: Our collective findings suggest that expression of PPARGC1A and lower mitochondrial number affect the metabolic phenotype in TS subjects.

Most rotavirus strains require the cation-independent mannose-6-phosphate receptor, sortilin-1, and cathepsins to enter cells.

Cathepsins, endosomal acid proteases, are transported from the trans-Golgi network to late endosomes by the mannose-6-phosphate receptor (M6PR). We have previously demonstrated that some rotavirus strains, like UK, Wa, WI61, DS-1, and YM, require the cation-dependent (CD-) M6PR and cathepsins to enter from late endosomes to the cytoplasm in MA104 cells, while other strains, like the simian strain RRV, which enter cells from maturing endosomes, do not. However, the role of other trans-Golgi network-late endosome transporters, such as the cation-independent (CI-) M6PR and sortillin-1, has not been evaluated. In this work, we found that several rotavirus strains that require the CD-M6PR for cell entry are also dependent on CI-M6PR and sortilin-1. Furthermore, we showed that the infectivity of all these rotavirus strains also requires cathepsins to enter not only MA104 cells, but also human intestinal Caco-2 cells. This study identifies sortilin-1 as a novel cell factor necessary for the infectivity of a virus; in addition, our results strongly suggest that cathepsins could be common cell factors needed for the infectivity of most rotavirus strains.

Rotaviruses reach late endosomes and require the cation-dependent mannose-6-phosphate receptor and the activity of cathepsin proteases to enter the cell.

UNLABELLED: Rotaviruses (RVs) enter cells through different endocytic pathways. Bovine rotavirus (BRV) UK uses clathrin-mediated endocytosis, while rhesus rotavirus (RRV) employs an endocytic process independent of clathrin and caveolin. Given the differences in the cell internalization pathway used by these viruses, we tested if the intracellular trafficking of BRV UK was the same as that of RRV, which is known to reach maturing endosomes (MEs) to infect the cell. We found that BRV UK also reaches MEs, since its infectivity depends on the function of Rab5, the endosomal sorting complex required for transport (ESCRT), and the formation of endosomal intraluminal vesicles (ILVs). However, unlike RRV, the infectivity of BRV UK was inhibited by knocking down the expression of Rab7, indicating that it has to traffic to late endosomes (LEs) to infect the cell. The requirement for Rab7 was also shared by other RV strains of human and porcine origin. Of interest, most RV strains that reach LEs were also found to depend on the activities of Rab9, the cation-dependent mannose-6-phosphate receptor (CD-M6PR), and cathepsins B, L, and S, suggesting that cellular factors from the trans-Golgi network (TGN) need to be transported by the CD-M6PR to LEs to facilitate RV cell infection. Furthermore, using a collection of UK × RRV reassortant viruses, we found that the dependence of BRV UK on Rab7, Rab9, and CD-M6PR is associated with the spike protein VP4. These findings illustrate the elaborate pathway of RV entry and reveal a new process (Rab9/CD-M6PR/cathepsins) that could be targeted for drug intervention. IMPORTANCE: Rotavirus is an important etiological agent of severe gastroenteritis in children. In most instances, viruses enter cells through an endocytic pathway that delivers the viral particle to vesicular organelles known as early endosomes (EEs). Some viruses reach the cytoplasm from EEs, where they start to replicate their genome. However, other viruses go deeper into the cell, trafficking from EEs to late endosomes (LEs) to disassemble and reach the cytoplasm. In this work, we show that most RV strains have to traffic to LEs, and the transport of endolysosomal proteases from the Golgi complex to LEs, mediated by the mannose-6-phosphate receptor, is necessary for the virus to exit the vesicular compartment and efficiently start viral replication. We also show that this deep journey into the cell is associated with the virus spike protein VP4. These findings illustrate the elaborate pathway of RV entry that could be used for drug intervention.