YY1 regulates skeletal muscle regeneration through controlling metabolic reprogramming of satellite cells.

Skeletal muscle satellite cells (SCs) are adult muscle stem cells responsible for muscle regeneration after acute or chronic injuries. The lineage progression of quiescent SC toward activation, proliferation, and differentiation during the regeneration is orchestrated by cascades of transcription factors (TFs). Here, we elucidate the function of TF Yin Yang1 (YY1) in muscle regeneration. Muscle-specific deletion of YY1 in embryonic muscle progenitors leads to severe deformity of diaphragm muscle formation, thus neonatal death. Inducible deletion of YY1 in SC almost completely blocks the acute damage-induced muscle repair and exacerbates the chronic injury-induced dystrophic phenotype. Examination of SC revealed that YY1 loss results in cell-autonomous defect in activation and proliferation. Mechanistic search revealed that YY1 binds and represses mitochondrial gene expression. Simultaneously, it also stabilizes Hif1α protein and activates Hif1α-mediated glycolytic genes to facilitate a metabolic reprogramming toward glycolysis which is needed for SC proliferation. Altogether, our findings have identified YY1 as a key regulator of SC metabolic reprogramming through its dual roles in modulating both mitochondrial and glycolytic pathways.

Bushen Yijing Fang Reduces Fall Risk in Late Postmenopausal Women with Osteopenia: A Randomized Double-blind and Placebo-controlled Trial.

Falls in late postmenopausal women with osteopenia usually cause fractures with severe consequences. This 36-month randomized, double-blind and placebo-controlled trial with a 10-year observational follow-up study aimed to investigate the long-term effect of herbal formula Bushen Yijing Fang (BSYJF) on fall risk in the late postmenopausal women with osteopenia. 140 late postmenopausal women (Femoral neck T-score, -2.5~-2 SD) were recruited and randomized to orally receive calcium carbonate 300 mg daily with either BSYJF or placebo for 36 months. The effect was further investigated for another 10-year follow-up. During the 36-month administration, there were 12 falls in BSYJF group and 28 falls in placebo group, respectively, indicating 64% lower risk of falls (RR 0.36 [95% CI, 0.18 to 0.71]; P = 0.004) in BSYJF group. During the 10-year follow-up, 36% lower fall risk (RR 0.64 [95% CI, 0.46 to 0.89]; P = 0.009) was observed in BSYJF group. No significant difference was found in safety profile between two groups. Thirty-six-month administration of BSYJF reduced fall risk with an increase in bone mass, and its latent effect on fall risk was continually observed in the 10-year follow-up in late postmenopausal women with osteopenia. This clinical trial was registered at Chinese clinical trial registry (ChiCTR-IOR-16008942).

[Molecular mechanism of effect of wenban humai granule on stability of atheromatous plaque].

OBJECTIVE: To explore the molecular mechanism of wenban humai granule (WHG) in stabilizing atheromatous plaque, by observing its effect on the collagen degradation and synthesis imbalance manner in the fibrous cap of the plaque. METHODS: Atherosclerosis (AS) rabbit model established by feeding high fat diet. The changes of protein and mRNA expression of macrophage CD68, metalloproteinase-1 (MMP-1), alpha-smooth muscle actin (alpha-SMA) and collagen I (C-I) in model rabbits' neo-genesic intima were determined by immunohistochemical stain and in situ hybridization methods before and after treatment as well as before and after modeling. RESULTS: After being fed with high fat diet for 7 weeks, the protein and mRNA expression of macrophage CD68, MMP-1 in neo-genesic intima of aorta in the model rabbits significantly increased, these changes could be significantly restored after 8 weeks treatment with WHG or simvastatin. At the same time, the expressions of alpha-SMA protein and C-I protein and mRNA slightly increased due to the immigration of SMC in aortic media to neo-genesic intima, these expressions could be further increased after WHG treatment but showed a reducing trend after simvastatin treatment (P < 0.05 and P < 0.01). In the whole course, positive correlation was shown between protein expressions of CD68 and MMP-1 (r = 0.952, P < 0.01) and also between these of alpha-SMA and C-I (r = 0.793, P < 0.01). CONCLUSION: WHG affects the collagen degradation and synthesis imbalance in the fibrous cap of the plaque to stabilize plaque through bi-directional regulation, up-regulating synthesis thesis factors and down-regulating degradation factors, while simvastatin perform its action on plaque stability by down-regulating degradation factors alone.