Buyang Huanwu decoction improves neural recovery after spinal cord injury in rats through the mTOR signaling pathway and autophagy.

BACKGROUND: Spinal cord injury (SCI) refers to the interruption of the tracts inside the spinal cord caused by various factors. The repair of damaged axons has always been a difficult point in clinical treatment and neuroscience research. The treatment of SCI with Buyang huanwu decoction (BYHWD), a well-known recipe for invigorating Qi (a vital force forming part of any living entity in traditional Chinese culture) and promoting blood circulation, shows a good effect. METHODS: The rubrospinal tract (RST) transection model in rats was established in this study and rats were administrated with low (BL), medium (BM), or high (BH) doses of BYHWD. RESULTS: Compared with the SCI group, BL, BM moderately, and BH significantly improved the motor function of forelimbs and increased the number of red nucleus neurons in SCI rats. As for the possible molecular mechanism, BL, BM moderately, and BH significantly increased mTOR whereas decreased Beclin-1 and LC3 in the red nucleus. CONCLUSION: In conclusion, low, medium, and high doses of BYHWD could promote neural recovery in SCI rats through improving motor function and neuron survival in the red nucleus. The neuroprotective effects of BYHWD might be associated with affecting the mTOR signaling pathway and autophagy.

Decreased miR-29 suppresses myogenesis in CKD.

The mechanisms underlying the muscle wasting that accompanies CKD are not well understood. Animal models suggest that impaired differentiation of muscle progenitor cells may contribute. Expression of the myogenesis-suppressing transcription factor Ying Yang-1 increases in muscle of animals with CKD, but the mechanism underlying this increased expression is unknown. Here, we examined a profile of microRNAs in muscles from mice with CKD and observed downregulation of both microRNA-29a (miR-29a) and miR-29b. Because miR-29 has a complementary sequence to the 3'-untranslated region of Ying Yang-1 mRNA, a decrease in miR-29 could increase Ying Yang-1. We used adenovirus-mediated gene transfer to express miR-29 in C2C12 myoblasts and measured its effect on both Ying Yang-1 and myoblast differentiation. An increase in miR-29 decreased the abundance of Ying Yang-1 and improved the differentiation of myoblasts into myotubes. Similarly, using myoblasts isolated from muscles of mice with CKD, an increase in miR-29 improved differentiation of muscle progenitor cells into myotubes. In conclusion, CKD suppresses miR-29 in muscle, which leads to higher expression of the transcription factor Ying Yang-1, thereby suppressing myogenesis. These data suggest a potential mechanism for the impaired muscle cell differentiation associated with CKD.

Evidence for adipose-muscle cross talk: opposing regulation of muscle proteolysis by adiponectin and Fatty acids.

Illnesses associated with insulin resistance exhibit increases in whole-body protein degradation and amino acid oxidation. However, the mechanisms stimulating muscle catabolism under these conditions are not clear. Because insulin resistance is associated with accumulation of lipids in muscle, we measured protein degradation in muscles of mice fed a high-fat diet. Muscle protein catabolism was accelerated on the high-fat diet, and this was associated with an increase in plasma free fatty acid and a decrease in plasma levels of the adipocyte-derived cytokine adiponectin. To evaluate how free fatty acids influence adiponectin-mediated changes in muscle protein breakdown we examined C2C12 skeletal muscle cells exposed to free fatty acids. Both saturated fatty acids (palmitate) and unsaturated fatty acids (oleate) increased protein degradation (25 and 18%, respectively) in part by activating the E3 ubiquitin ligases. Adenovirus-mediated overexpression of adiponectin blocked fatty acid-induced protein degradation in C2C12 cells. Palmitate activated the E3 ubiquitin ligases by suppressing insulin receptor substrate-1/Akt signaling in the C2C12 muscle cells, whereas adiponectin attenuated the E3 ubiquitin ligase activation by increasing both insulin receptor substrate-1 tyrosine phosphorylation and Akt Ser473 phosphorylation. In related experiments, adiponectin overexpression decreased TNFalpha and IL-6 expression in 3T3-L1 adipocytes, whereas exposure to free fatty acids had the opposite effect. We conclude that the balance between free fatty acids and adiponectin impacts muscle proteolysis in insulin-resistant conditions and suggest a role for adipose tissue-muscle cross talk in diabetes and obesity.