Abstract Background: Exposure to high altitude environment leads to skeletal muscle atrophy. As a hormone secreted by skeletal muscles after exercise, irisin contributes to promoting muscle regeneration and ameliorating skeletal muscle atrophy, but its role in hypoxia-induced skeletal muscle atrophy is still unclear. Methods & Results: Our results showed that 4 w of hypoxia exposure significantly reduced body weight and gastrocnemius muscle mass of mice, as well as grip strength and the duration time of treadmill exercise. Hypoxia treatment increased HIF-1α expression and decreased both the circulation level of irisin and its precursor protein FNDC5 expression in skeletal muscle. In vitro , CoCl 2 -induced chemical hypoxia and 1% O 2 ambient hypoxia both reduced FNDC5, along with the increase of HIF-1α. Moreover, the decline of area and diameter of myotubes caused by hypoxia were rescued by inhibiting HIF-1α via YC-1. and Conclusions: Collectively, our research indicated that FNDC5/irisin was negatively regulated by HIF-1α and could participate in the regulation of muscle atrophy caused by hypoxia.
Abstract Background The true incidence of acute gastrointestinal illness in China is underrecognized by surveillance systems. The aims of this study were to estimate the incidence and prevalence of self-reported AGI in the community of China, and to investigate sociodemographic and epidemiological determinants of AGI. Methods We conducted a 12-months cross-sectional population-based survey in eight provinces of China during 2014–2015. The survey determined the prevalence and incidence of acute gastrointestinal illness (AGI) in the total permanent resident population in China according to the census of the population in 2010. The random multilevel population sample was stratified by geographic, population, and socioeconomic status. We used a recommended case definition of AGI, with diarrhea (three loose or watery stools) and/or any vomiting in a four-week recall. A face-to-face survey was conducted by selecting the member in the household with the most recent birthday. Results Among 56,704 sampled individuals, 948 (1,134 person-time) fulfilled the case definition; 98.5% reported diarrhea. This corresponds to 2.3% (95% CI:1.9%-2.8%) of an overall standardized four-week prevalence and 0.3 (95% CI: 0.23–0.34) episodes per person-year of annual adjusted incidence rate. There was no significant difference between males and females. The incidence rates were higher among urban residents, and in the spring and summer. In the whole study period, 50% of the cases sought medical care, of which 3.9% were hospitalized and 14.3% provided a biological sample for laboratory identification of the causative agent. Children aged 0–4 and young adults aged 15–24, people living in rural areas and people who traveled frequently had higher prevalence of AGI. Conclusion Results showed that AGI represents a substantial burden in China, and will contribute to the estimation of the global burden of AGI. Complemented with data on the etiologies of AGI, these estimates will form the basis to estimate the burden of foodborne diseases in China.
Abstract This study aims to explore the role of FoxO1 and its acetylation in the alleviation of hypoxia‐induced muscle atrophy by resistance training. Forty male Sprague–Dawley rats were randomly divided into four groups: normoxic control group (C), normoxic resistance training group (R), hypoxic control group (H) and hypoxic resistance training group (HR). Rats in R and HR groups were trained on an incremental weight‐bearing ladder every other day, while those in H and HR groups were kept in an environment containing 12.4% O 2 . After 4 weeks, muscles were collected for analysis. Differentiated L6 myoblasts were analysed in vitro after hypoxia exposure and plasmids transfection (alteration in FoxO1 acetylation). The lean body mass loss, wet weight and fibre cross‐sectional area of extensor digitorum longus of rats were decreased after 4 weeks hypoxia, and the adverse reactions above was reversed by resistance training. At the same time, the increase in hypoxia‐induced autophagy was suppressed, which was accompanied by a decrease in the expression of nuclear FoxO1 and cytoplasmic Ac‐FoxO1 by resistance training. The L6 myotube diameter increased and the expression of autophagic proteins were inhibited under hypoxia via intervening by FoxO1 deacetylation. Overall, resistance training alleviates hypoxia‐induced muscle atrophy by inhibiting nuclear FoxO1 and cytoplasmic Ac‐FoxO1‐mediated autophagy.
To explore the application of multivariate response model with multilevel in the influencing factors of blood pressure.Two response model with three-level was fitted under MLwin 2.02 software.The correlation coefficient between systolic blood pressure (SBP) and diastolic blood pressure (DBP) was 0.949 at region level, and 0.701 at individual level. SBP and DBP level increased with age, while the regression coefficient of age on SBP was significantly higher than on DBP, beta was 0.720 (SBP) and 0.118 (DBP) individually (chi2 = 4284.56, P < 0.001). The DBP and SBP level of male were higher than that of female, while the regression coefficient of gender on DBP was significantly higher than on SBP, beta was 2.208 (SBP) and 3.113 (DBP) individually (chi2 = 31.35, P < 0.001).Multivariate response model with multilevel can be used to analyze the hierarchy structure data, and it is also a good tool to analyze the influencing factors of blood pressure.
Objective Brown adipose tissues (BAT) activation is important for losing weight as its high energy expenditure in Mammalian. Recent studies showed that exercise may also be essential for BAT activation. Uncoupling protein 1 (UCP1), specifically expressed in BAT's mitochondria, uncouples oxidative phosphorylation and dissipates energy from Free Fatty Acids into heat. Activating the Adrenergic Receptor β3 (Adrβ3) provides fuel for mitochondrial heat production and up-regulates Cyclooxygenase 2 (COX2), which is a key factor of UCP1 synthesis. Sympathetic nerve excitement stimulated by exercise can release norepinephrine as a neurotransmitter, which can affect Adrβ3. Brown adipocyte (BAC) is a kind of adipocyte in vitro as a model to study heat production. Isoprenaline Hydrochloride (ISO) is a widely used as an Adrβ agonist. In this research, we tried to figure out the response of BAC to Adrβ3 activations with different time points and whether ISO can be used as a BAC activator.
Methods C3H10T1/2 cells were maintained in a humidified, 37°C, 5% CO2 incubator in DMEM/F12 medium with 10% fetal bovine serum (FBS). For brown adipogenesis, cells were first split into differentiation medium (DMEM/F12 containing 10% FBS, 20nM insulin, 1nM 3,3’5-Triiodo-L-thyronine(T3)) for 4 days, the medium was changed every other day. Confluent cells were treated for 2 days with brown adipose adipogenesis cocktails (differentiation medium containing 2µg/mL dexamethasone, 0.5mM isobutylmethylxanthine (IBMX), 0.125mM indomethacin and 1µM rosiglitazone) on day 4. Then the medium was replaced by differentiation medium and changed every other day. At day 10, the full differentiation adipocytes were treated with 10µM ISO for 0 (as control), 1, 3, 6, 12 and 24 hours. For the lipid droplets staining, the cells were fixed by 4% paraformaldehyde solution then stained with Oil Red O. The cells were harvested and the total cell lysates were extracted for protein analysis after each time point. The UCP1, COX2, and Adrβ3 expression levels were detected by western blot, using Actin as the internal protein. The results were expressed as the mean ± standard error of the mean (SEM). Group comparisons were performed using two-way ANOVA and LSD’s post-hoc tests.
Results After differentiation, the cell shapes converted from fibroblastic to a spherical shape. Dispersed small lipid droplets were observed in the cells. After ISO treatment, the red color after Oil Red Staining became lighter and the size of the lipid droplets turned to smaller. The Adrβ3 protein expressions were 1.00±0.00, 1.34±0.32, 1.07±0.50, 4.65±1.84*, 2.44±0.73, and 3.43±1.09 at 0h, 1h, 3h, 6h, 12h, and 24h after ISO treatment, respectively. After introduced to ISO, the UCP1 expression levels were 1.00±0.00, 1.95±0.39, 2.72±0.57, 5.68±1.82*, 3.49±0.92, and 2.79±1.05 at 0h, 1h, 3h, 6h, 12h, and 24h, respectively. And for COX2, the protein expressions were 1.00±0.00, 2.13±0.67, 1.82±0.33, 4.67±1.82*, 2.88±0.44, and 2.65±0.54, respectively. The * means p ˂ 0.05, compared with oh controls. The proteins expressions were reached to peak after 6 hours ISO treatment from the above results.
Conclusions UCP1 and COX2 protein expressions were increased in BAC according to Adrβ3's expression in different time points, indicating that Adrβ3 may induce adipolysis in BAC and help to burn fat and produce heat.
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