Obesity is an increasing public health concern worldwide. According to the latest Organization for Economic Co-operation and Development (OECD) report (2014), the incidence of child obesity in Korea has exceeded the OECD average. To better understand and control this condition, the present study examined the composition of the gut microbial community in normal and obese adolescents. Fecal samples were collected from 67 obese (body mass index [BMI] ≥ 30 kg/m2, or ≥ 99th BMI percentile) and 67 normal (BMI < 25 kg/m2 or < 85th BMI percentile) Korean adolescents aged 13–16 years and subjected to 16S rRNA gene sequencing. Analysis of bacterial composition according to taxonomic rank (genus, family, and phylum) revealed marked differences in the Bacteroides and Prevotella populations in normal and obese samples (p < 0.005) at the genus and family levels; however, there was no difference in the Firmicutes-to-Bacteroidetes (F/B) ratio between normal and obese adolescents samples at the phylum level (F/B normal = 0.50 ± 0.53; F/B obese = 0.56 ± 0.86; p = 0.384). Statistical analysis revealed a significant association between the compositions of several bacterial taxa and child obesity. Among these, Bacteroides and Prevotella showed the most significant association with BMI (p < 0.0001 and 0.0001, respectively). We also found that the composition of Bacteroides was negatively associated with triglycerides (TG), total cholesterol, and high-sensitive C-reactive protein (hs-crp) (p = 0.0049, 0.0023, and 0.0038, respectively) levels, whereas that of Prevotella was positively associated with TG and hs-crp levels (p = 0.0394 and 0.0150, respectively). We then applied the association rule mining algorithm to generate “rules” to identify the association between the populations of multiple bacterial taxa and obesity; these rules were able to discriminate obese from normal states. Therefore, the present study describes a systemic approach to identify the association between bacterial populations in the gut and childhood obesity.

This study aimed to develop a multidisciplinary lifestyle intervention program targeted at children and adolescents with moderate to severe obesity, and assess the additional effects of exercise intervention when compared to usual care. Overall, the 103 enrolled participants were ≥85th percentile of age and sex-specific body mass index (BMI). Participants were divided into groups that received 16 weeks of either usual care or exercise intervention. The BMI z-score of the overall completers decreased by about 0.05 after the 16-week intervention (p = 0.02). After the intervention, only the exercise group had a significantly lower BMI z-score than the baseline score by about 0.1 (p = 0.03), but no significant group by time interaction effects were observed. At the 16-week follow-up, significant group by time interaction effects were observed in percentage body fat (%BF) (β = −1.52, 95%CI = −2.58–−0.45), lean body mass (LM) (β = 1.20, 95%CI = 0.12–2.29), diastolic blood pressure (β = −5.24, 95%CI = −9.66–−0.83), high-sensitivity C-reactive protein (β = −1.67, 95%CI = −2.77–−1.01), and wall sit test score (β = 50.74, 95%CI = 32.30–69.18). We developed a moderate-intensity intervention program that can be sustained in the real-world setting and is practically applicable to both moderate and severe obesity. After interventions, the exercise group had lower %BF and cardiometabolic risk markers, and higher LM and leg muscle strength compared to the usual care group.

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Coxsackievirus B3 (CVB3) is nonenveloped and has a single-stranded positive-sense RNA genome. CVB3 induces myocarditis and ultimately dilated cardiomyopathy. Although there are mounting evidences of an interaction between CVB3 particles and the cellular receptors, coxsackievirus and adenovirus receptor (CAR) and decay-accelerating factor (DAF), very little is known about the mechanisms of internalization and trafficking. In the present study, we used the CVB3 H3 strain, which is CAR-dependent but DAF-independent Woodruff variant and found that during entry, CVB3 particles were colocalized in clathrin, after interacting primarily with CAR, which was not recycled to the plasma membrane. We also found that CVB3 internalization was dependent on the function of dynamin, a large GTPase that has an essential role in endocytosis. Heat-shock cognate protein, Hsc70, which acts as a chaperone in the release of coat proteins from clathrin-coated vesicles (CCV), played a role in CVB3 trafficking processes. Moreover, endosomal acidification was crucial for CVB3 endocytosis. Finally, CVB3 was colocalized in early endosome autoantigen 1 (EEA1) molecules, which are involved in endosome-endosome tethering and fusion. In conclusion, these data together indicate that CVB3 uses clathrin-mediated endocytosis and is transcytosed to early endosomes.

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