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Abstract: Muscle atrophy poses a serious concern to patients inflicted with inflammatory diseases. There is now increasing evidence which suggests a vital role for tumor necrosis factor alpha (TNF-α) in muscle pathology associated with impairment of differentiation and muscle wasting. Resveratrol has been an ascribed inhibitory effect on glucocorticoid-induced muscle atrophy in vitro, but the influence of resveratrol on the growth of C2C12 myotubes exposed to TNF-α remains unclear. The present study aimed to investigate the involvement of TNF-α in the regulation of skeletal muscle hypertrophy and atrophy, and the possibility to interfere with such modulations by means of resveratrol supplementation. For this purpose, C2C12 myotubes were treated with TNF-α in the presence or absence of resveratrol. Myotube treatment with TNF-α contributes to both hyperexpression of the muscle-specific ubiquitin ligase MAFbx and MuRF1, and these alterations are linked to a decrease of anabolic targets (Akt, mTOR, p70S6k and 4E-BP1) and an increase of catabolic targets (FoxO1, FoxO3a, MAFbx and MuRF1). Resveratrol supplementation effectively counteracts TNF-α induced muscle protein loss and reverses declining expression of Akt, mTOR, p70S6K, 4E-BP1and FoxO1, but exerts no influence of FoxO3a expression. Our study demonstrates that resveratrol can reverse the muscle cell atrophy caused by TNF-α through regulation of the Akt/mTOR/FoxO1 signaling pathways, followed by inhibition of the atrophy-related ubiquitin ligase. Our findings suggested that resveratrol could represent a possible strategy to improve muscle mass. [Copyright &y& Elsevier]

• In this work, we firstly found the Shp2 expression in BMSCs was higher in B-ALL patients than in normal donors, especially in relapsed B-ALL patients. • We firstly found Shp2 activation in bone marrow microenvironment upregulated PI3K/AKT phosphorylation to increase VCAM-1 expression. • Shp2 activation in bone marrow microenvironment induced VCR resistance in CCRF-SB cells via VCAM-1/VLA-1 signaling between BMSCs and leukemia cells. • These provided a basis for the study on the effect of Shp2 activity on leukemia cells in the BM microenvironment. B-cell acute lymphoblastic leukemia (B-ALL) is immune to the chemotherapy-induced apoptosis as a result of the protection of bone marrow mesenchymal stromal cells (BMSCs). However, the precise underlying mechanism of such protection remains unclear so far. In this experiment, protein tyrosine phosphatase 2 (Shp2), which was encoded by the PTPN11 gene, was highly expressed in BMSCs of the newly diagnosed and the recurrent B-ALL patients. The plasmid-induced (including Shp2 E76K) Shp2 activation in BMSCs (Shp2-activated BMSCs) markedly increased the BMSCs-mediated resistance of leukemia cells both in vitro and in vivo. Additionally, studies in vitro suggested that, the expression of vascular cell adhesion molecule 1 (VCAM-1) was markedly up-regulated in Shp2-activated BMSCs, and VCAM-1 expression in BMSCs of B-ALL patients was negatively correlated with Shp2 expression. Down-regulation of VCAM-1 in BMSCs using siRNA reversed the resistance of CCRF-SB cells mediated by the Shp2-activated BMSCs. As for the molecular mechanism, the PI3K/AKT pathway mediated the regulation of VCAM-1 by Shp2. Blocking the very late antigen-4 (VLA-4) by antibodies in CCRF-SB cells dramatically reversed the resistance of CCRF-SB cells mediated by the Shp2-activated BMSCs, and decreased the adhesion effects of both CCRF-SB cells and BMSCs. In conclusion, Shp2 activation in BMSCs up-regulates VCAM-1 expression through increasing the PI3K/AKT phosphorylation level, and targeting the VCAM-1/VLA-4 signaling may serve as a clinically relevant mechanism to overcome the BMSCs-mediated chemoresistance of B-ALL cells. [ABSTRACT FROM AUTHOR]

Abstract: Ligustilide, the major component of Angelica sinensis, is also thought to be the most potent bioactive constituent of this plant. Ligustilide has been reported to markedly protect neural tissue against apoptosis. However, little is known regarding ligustilide's anti-apoptosis effect in muscle tissue. The aim of the study was to investigate the anti-apoptosis effects of ligustilide on TNF-α-induced C2C12 cells during differentiation. It was revealed that ligustilide at various concentrations significantly prevented the apoptosis of C2C12 cells incubated in TNF-α as assessed by apoptosis index and DNA fragmentation. Moreover, ligustilide-treated groups exhibited a significant increase in the bcl-2/bax ratio, pro-caspase 3 and pro-caspase 8 compared with the TNF-α-control group in a dose-dependent manner. Meanwhile, ligustilide-treated groups presented a significantly increased level of phosphorylated Akt and suppressed expression of the myogenin protein. Therefore, the findings derived suggested that ligustilide protected C2C12 cells from TNF-α-induced apoptosis during differentiation by reducing apoptosis and inducing cell proliferation. [Copyright &y& Elsevier]