Long-term exercise training down-regulates m6A RNA demethylase FTO expression in the hippocampus and hypothalamus: an effective intervention for epigenetic modification.

BACKGROUND: Exercise boosts the health of some brain parts, such as the hippocampus and hypothalamus. Several studies show that long-term exercise improves spatial learning and memory, enhances hypothalamic leptin sensitivity, and regulates energy balance. However, the effect of exercise on the hippocampus and hypothalamus is not fully understood. The study aimed to find epigenetic modifications or changes in gene expression of the hippocampus and hypothalamus due to exercise. METHODS: Male C57BL/6 mice were randomly divided into sedentary and exercise groups. All mice in the exercise group were subjected to treadmill exercise 5 days per week for 1 h each day. After the 12-week exercise intervention, the hippocampus and hypothalamus tissue were used for RNA-sequencing or molecular biology experiments. RESULTS: In both groups, numerous differentially expressed genes of the hippocampus (up-regulated: 53, down-regulated: 49) and hypothalamus (up-regulated: 24, down-regulated: 40) were observed. In the exercise group, increased level of N6-methyladenosine (m6A) was observed in the hippocampus and hypothalamus (p < 0.05). Furthermore, the fat mass and obesity-associated gene (FTO) of the hippocampus and hypothalamus were down-regulated in the exercise group (p < 0.001). In addition, the Fto co-expression genes of the mouse brain were studied and analyzed using database to determine the potential roles of exercise-downregulated FTO in the brain. CONCLUSION: The findings demonstrate that long-term exercise might elevates the levels of m6A-tagged transcripts in the hippocampus and hypothalamus via down-regulation of FTO. Hence, exercise might be an effective intervention for epigenetic modification.

FTO is a transcriptional repressor to auto-regulate its own gene and potentially associated with homeostasis of body weight.

Fat mass and obesity-associated (FTO) protein is a ferrous ion (Fe2+)/2-oxoglutarate (2-OG)-dependent demethylase preferentially catalyzing m6A sites in RNA. The FTO gene is highly expressed in the hypothalamus with fluctuation in response to various nutritional conditions, which is believed to be involved in the control of whole body metabolism. However, the underlying mechanism in response to different nutritional cues remains poorly understood. Here we show that ketogenic diet-derived ketone body ß-hydroxybutyrate (BHB) transiently increases FTO expression in both mouse hypothalamus and cultured cells. Interestingly, the FTO protein represses Fto promoter activity, which can be offset by BHB. We then demonstrate that FTO binds to its own gene promoter, and Fe2+, but not 2-OG, impedes this binding and increases FTO expression. The BHB-induced occupancy of the promoter by FTO influences the assembly of the basal transcriptional machinery. Importantly, a loss-of-function FTO mutant (I367F), which induces a lean phenotype in FTOI367F mice, exhibits augmented binding and elevated potency to repress the promoter. Furthermore, FTO fails to bind to its own promoter that promotes FTO expression in the hypothalamus of high-fat diet-induced obese and 48-h fasting mice, suggesting a disruption of the stable expression of this gene. Taken together, this study uncovers a new function of FTO as a Fe2+-sensitive transcriptional repressor dictating its own gene switch to form an auto-regulatory loop that may link with the hypothalamic control of body weight.

Screening for Neuraminidase Inhibitory Activity in Traditional Chinese Medicines Used to Treat Influenza.

OBJECTIVE: To screen for influenza virus neuraminidase inhibition and to provide a reference for the clinical treatment of influenza using traditional Chinese medicines (TCM). In this study, 421 crude extracts (solubilized with petroleum ether, ethanol, ethyl acetate, and aqueous solvents) were obtained from 113 TCM. The medicine extracts were then reacted with oseltamivir, using 2'-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid (MUNANA) as the substrate, to determine influenza virus neuraminidase activity using a standard fluorimetric assay. It was found that Chinese medicine extracts from Pyrola calliantha, Cynanchum wilfordii, Balanophora involucrata and Paeonia delavayi significantly inhibited neuraminidase activity at a concentration of 40 µg/mL. Dose-dependent inhibitory assays also revealed significant inhibition. The IC50 range of the TCM extracts for influenza virus neuraminidase was approximately 12.66-34.85 µg/mL, respectively. Some Chinese medicines have clear anti-influenza viral effects that may play an important role in the treatment of influenza through the inhibition of viral neuraminidase. The results of this study demonstrated that plant medicines can serve as a useful source of neuraminidase (NA) inhibitors and further investigation into the pharmacologic activities of these extracts is warranted.

[Correlation of Ca2+ current features of nasopharyngeal carcinoma cells with different metastatic potentiality to their moving abilities].

BACKGROUND & OBJECTIVE: The metastatic potentiality of malignancies is closely associated with their biological dynamic properties, which are affected by intracellular Ca2+ current activity. This study was to investigate the correlation of Ca2+ current features of sub-clonal nasopharyngeal carcinoma (NPC) cell lines 5-8F and 6-10B with different metastatic potentiality to their moving abilities. METHODS: 5-8F cells, with higher metastatic potentiality, and 6-10B cells, with lower metastatic potentiality, were cultured with herbal medicine-containing serum, which holds significant metastasis-inhibiting effect on tumor cells. Cell proliferation was assessed by MTT assay. The expression of nm23-H1 was detected by Western blot. Intracellular Ca2+ current features were detected with patch clamp technique in a whole cell recording way, while cell moving ability was determined by streak culturing assay. RESULTS: The expression of nm23-H1 was significantly lower in 5-8F cells than in 6-10B cells (2.3+/-0.2 vs. 2.9+/-0.4). The Ca2+ release-activated Ca2+ influx current (ICRAC) was significantly lower in 5-8F cells than in 6-10B cells [(-1.39+/-0.36) nA vs. (-0.66+/-0.40) nA, P < 0.05]. The number of cells moved across the streak was significantly higher in 5-8F cells than in 6-10B cells (350+/-3 vs. 246+/-1, P< 0.05). When cultured with herbal medicine-containing serum, no significant difference in proliferation was found between 5-8F cells and 6-10B cells; the expression of nm23-H1 was significantly higher in 5-8F cells than in 6-10B cells(3.9+/-0.1 vs.1.0+/-0.1,P<0.05)û the ICRAC was decreased to (-1.27+/-0.35) nA in 5-8F cells and decreased to (-0.37+/-0.23) nA in 6-10B cell, and the inhibition rate was significantly higher in 5-8F cells than in 6-10B cells [(1.90+/-0.47)% vs. (0.46+/-0.12)%, P < 0.05]û the number of cells moved across the streak was significantly lower in 5-8F cells than in 6-10B cells (94+/-6 vs. 229+/-6, P < 0.05). CONCLUSIONS: There are significant differences in nm23-H1 protein expression, ICRAC level and cell moving ability between 5-8F and 6-10B cells. Medicine intervention could inhibit Ca2+ current and moving ability of 5-8F cells, and meanwhile increase the nm23-H1 activity.

[Correlation between TCM syndrome type and intracranial aggressive potentiality of untreated nasopharyngeal carcinoma].

OBJECTIVE: To investigate the correlation between TCM syndrome type and intracranial aggressive potentiality of untreated nasopharyngeal carcinoma (NPC). METHODS: Sixty untreated NPC patients of different syndrome types were treated conventionally and followed up for over one year. Correlation between the TCM syndrome type differentiated at the first consultation and the intracranial aggressive potentiality of the primary focus of NPC were analyzed. RESULTS: The incidence of intracranial aggression was significantly higher in patients with Qi-Yin deficiency type than that in those with other two syndrome types during the follow-up period (P < 0.01). CONCLUSION: The intracranial aggessive rate in the untreated NPC patients of Qi-Yin deficiency type was higher than in those of either Qi and blood coagulation type or fire-toxin stagnation type.