Ginsenoside F2-Mediated Intestinal Microbiota and Its Metabolite Propionic Acid Positively Impact the Gut-Skin Axis in Atopic Dermatitis Mice.

Atopic dermatitis (AD) is a complex inflammatory skin disease induced by multiple factors. AD can also cause intestinal inflammation and disorders of the gut microbiota. Ginseng is a kind of edible and medicinal plant; its main active components are ginsenosides. Ginsenosides have a variety of anti-inflammatory effects and regulate the gut microbiota; however, their role in AD and the underlying mechanisms are unclear. In this study, we found that intragastric administration of ginsenoside F2 improved AD-like skin symptoms and reduced inflammatory cell infiltration, serum immunoglobulin E levels, and mRNA expression of inflammatory cytokines in AD mice. 16s rRNA sequencing analysis showed that ginsenoside F2 altered the intestinal microbiota structure and enriched the short-chain fatty acid-producing microbiota in AD mice. Metabolomic analysis revealed that ginsenoside F2 significantly increased the propionic acid (Pa) content of feces and serum in AD mice, which was positively correlated with significant enrichment of Parabacteroides goldsteinii and Lactobacillus plantarum in the intestines. Pa inhibits inflammatory responses in the gut and skin of AD mice through the G-protein-coupled receptor43/NF-κB pathway, thereby improving skin AD symptoms. These results revealed, for the first time, the mechanism by which ginsenoside F2 improves AD through the Pa (a metabolite of intestinal microbiota)-gut-skin axis.

Ginsenoside Rg1 activates brown adipose tissue to counteract obesity in high-fat diet-fed mice by regulating gut microbes and bile acid composition.

Obesity is a global health problem strongly linked to gut microbes and their metabolites. In this study, ginsenoside Rg1 (Rg1) reduced lipid droplet size and hepatic lipid accumulation by activating uncoupling protein 1 expression in brown adipose tissue (BAT), which in turn inhibited high-fat diet (HFD)-induced weight gain in mice. Furthermore, the intestinal flora of mice was altered, the abundance of Lachnoclostridium, Streptococcus, Lactococcus, Enterococcus and Erysipelatoclostridium was upregulated, and the concentrations of fecal bile acids were altered, with cholic acid and taurocholic acid concentrations being significantly increased. In addition, the beneficial effects of Rg1 were eliminated in mice treated with a combination of antibiotics. In conclusion, these results suggest that Rg1 activates BAT to counteract obesity by regulating gut microbes and bile acid composition in HFD-fed mice.

Effects of myostatin gene knockout on porcine extraocular muscles.

Myostatin (MSTN), a negative regulator of skeletal muscle mass, is not well known in extraocular muscles (EOMs). EOMs are specialized skeletal muscles. Hence, in this study, the effect of MSTN on the superior rectus (SR) and superior oblique (SO) of 2-month-old MSTN knockout (MSTN-/-) and wild-type (WT) pigs of the same genotype was investigated. SR (P < 0.01) and SO (P < 0.001) fiber cross-sectional areas of MSTN-/- pigs were significantly larger than those of WT pigs. Compared with WT pigs, MSTN-/- SO displayed a decrease in type I fibers (WT: 27.24%, MSTN-/-: 10.32%, P < 0.001). Type IIb fibers were higher in MSTN-/- pigs than in WT pigs (WT: 30.38%, MSTN-/-: 62.24%, P < 0.001). The trend in SR was the same as that in SO, although the trend in SO was greater than that in SR. The expression of myogenic differentiation factor (MyoD) and myogenic (MyoG) showed a significant increase in MSTN-/- SO (about 2.5-fold and 2-fold, respectively at the gene expression level, about 1.5-fold at the protein level) compared with WT pigs. MSTN plays an important role in the development of EOMs and regulates the muscle fiber type by modulating the gene expression of MyoD and MyoG in pigs.

Gastrodia elata Blume extract improves high-fat diet-induced type 2 diabetes by regulating gut microbiota and bile acid profile.

In this study, we aimed to characterize the anti-type 2 diabetes (T2D) effects of Gastrodia elata Blume extract (GEBE) and determine whether these are mediated through modification of the gut microbiota and bile acids. Mice were fed a high-fat diet (HFD), with or without GEBE, and we found that GEBE significantly ameliorated the HFD-induced hyperglycemia, insulin resistance, and inflammation by upregulating glucose transporter 4 (GLUT4) and inhibiting the toll-like receptor 4-nuclear factor kappa-B signaling pathway in white adipose tissue (WAT). In addition, we found that GEBE increased the abundance of Faecalibaculum and Lactobacillus, and altered the serum bile acid concentrations, with a significant increase in deoxycholic acid. The administration of combined antibiotics to mice to eliminate their intestinal microbiota caused a loss of the protective effects of GEBE. Taken together, these findings suggest that GEBE ameliorates T2D by increasing GLUT4 expression in WAT, remodeling the gut microbiota, and modifying serum bile acid concentrations.

Positive growth of smooth muscle in uterine horns of myostatin homozygous mutant gilt.

Current studies on myostatin (MSTN), a well-known negative regulator of skeletal muscle, studies mainly focus on the its effects on skeletal muscle.However, its effects on smooth muscle are less studied, especially in the uterine horns. To identify the role of MSTN in uterine horn smooth muscle, this study used 6-8-month-old homozygous MSTN mutant (MSTN-/-) gilts in anoestrum as animal models. Histochemical and immunofluorescence staining, western blotting, and RT-qPCR were performed. The results showed that the uteri of the MSTN-/- gilts were morphologically normal, and the uterine horn smooth muscle content was increased (MSTN-/-: 75.19%, Wild type: 51.52%, P < 0.01). In vivo immunofluorescence staining showed that the expression of the uterine horn smooth muscle-specific marker proteins, namely α-smooth muscle actin (ACTA2) and calponin, increased after MSTN knockout (1.41- and 1.21-fold, respectively, P < 0.05). Increased gene expression was also seen in MSTN-/- gilts in vivo for ACTA2 (approximately 2-fold), smooth muscle myosin heavy chain (7.14-fold), myocardin (9.32-fold), and serum response factor (2.17-fold). Protein expression of smooth muscle-specific markers was increased (1.51-fold for ACTA2, 1.57-fold for calponin, P<0.05). MSTN knockout promoted proliferation of the smooth muscle cell and the gene expression of c-kit, a peristaltic marker (2.43-fold, P < 0.05). The results of the in vitro experiments were consistent with those of the in vivo experiments. The present study indicates that MSTN knockout can increase the smooth muscle content of uterine horns, thus providing potential therapeutic targets for pregnancy disorders caused by increased smooth muscle content.

miR-320 regulates myogenesis by targeting growth factor receptor-bound protein-2 and ameliorates myotubes atrophy.

Loss of muscle mass can lead to diseases such as sarcopenia, diabetes, and obesity, which can worsen the quality of life and increase the incidence of disease. Therefore, understanding the mechanism underlying skeletal muscle differentiation is vital to prevent muscle diseases. We previously found that microRNA-320 (miR-320) is highly expressed in the lean muscle-type pigs, but its regulatory role in myogenesis remains unclear. The bioinformatics prediction indicated that miR-320 could bind to the 3 'untranslated region of growth factor receptor-bound protein-2 (Grb2). We hypothesized that miR-320 targets Grb2 to regulate myoblasts differentiation. To verify this, we transfected miR-320 mimic and inhibitor into C2C12 myoblasts to assess the role of miR-320 during myoblasts differentiation. We used real-time qPCR, luciferase reporter assays, and western blotting to confirm that miR-320 directly targets Grb2 to promote myoblasts differentiation. Moreover, by using a dexamethasone-induced atrophic model of myotubes, we discovered that miR-320 promotes the repair of damaged myotubes. Our findings expand understanding of miRNAs and genes related to regulating skeletal muscle differentiation, and provide insight into underlying therapeutic strategies for muscle diseases.