Effects of Hippo signaling on anti-oxidative stress of mesenchymal stem cells in vitro / 中华危重病急救医学

ABSTRACT

Objective To explore the effects of Hippo signaling on anti-oxidative stress of mouse marrow mesenchymal stem cells (mMSCs) in vitro. Methods mMSCs derived from C57BL/6 mice were identified using fluorescence-activated cell sorting analysis and the capabilities of osteogenic, chondrogenic and adipogenic differentiation were evaluated. 2-deoxy-D-glucose (2-DG) or XMU-MP-1 was used to modulate Hippo signaling. Oxidative stress was induced by H2O2treatment and the effect of oxidative stress induced by H2O2on survival of mMSCs was evaluated using methyl thiazolyl tetrazolium (MTT) assay. The effect of oxidative stress induced by H2O2on Hippo signaling and the effect of Hippo signaling on capability of anti-oxidative stress of mMSCs were analyzed through apoptosis-regulated proteins (Bcl-2 and Bax) using Western Blot. Results Hippo signaling was activated by 2-DG in a concentration-dependent manner and the effect was most prominent by 5 mmol/L of 2-DG [compared with the blank control group, large tumor suppressor 1 (LATS1) protein (grey value) 2.33±0.25 vs. 0.98±0.03, phosphorylated Yes-associated protein (p-YAP)/YAP protein ratio (grey value) 2.30±0.35 vs. 1.01±0.05, 14-3-3 protein (grey value)2.19±0.40 vs. 0.99±0.04, all P < 0.05]; Hippo signaling was inhibited by 100 nmol/L of XMU-MP-1 [compared with the blank control group, LATS1 protein (grey value) 0.69±0.10 vs. 0.98±0.03, p-YAP/YAP protein ratio (grey value)0.65±0.06 vs. 1.01±0.05, 14-3-3 protein (grey value) 0.75±0.11 vs. 0.99±0.04, all P < 0.05]. Death of mMSCs was induced by H2O2in a concentration-dependent manner and the minimal effective concentration was 0.1 mmol/L [compared with the blank control group, survival rate of mMSCs (81.25±11.85)% vs. (100.44±12.39)%, P < 0.05]. Inhibition of Hippo signaling was induced by H2O2in a concentration-dependent manner and the minimal effective concentration was also 0.1 mmol/L [compared with the blank control group, LATS1 protein (grey value) 0.75±0.06 vs. 1.01±0.09, p-YAP/YAP protein ratio (grey value) 0.69±0.05 vs. 0.98±0.05, both P < 0.05], those effects might associate with reduction of Bcl-2/Bax ratio (grey value 0.48±0.18 vs. 1.06±0.09, P < 0.05). Compared with the treatment of 0.1 mmol/L of H2O2, activation of Hippo signaling by 5 mmol/L of 2-DG [ LATS1 protein (grey value)0.95±0.05 vs. 0.64±0.06, p-YAP/YAP protein ratio (grey value) 0.87±0.03 vs. 0.45±0.16, both P < 0.05] improved survival of mMSCs [(92.80±9.43)% vs. (75.47±9.43)%, P < 0.05] through an increase of Bcl-2/Bax ratio (grey value1.14±0.16 vs. 0.77±0.12, P < 0.05); however, inhibition of Hippo signaling by 100 nmol/L of XMU-MP-1 [ LATS1 protein (grey value) 0.39±0.03 vs. 0.64±0.06, p-YAP/YAP protein ratio (grey value) 0.28±0.04 vs. 0.45±0.16, both P < 0.05] decreased survival of mMSCs [(57.54±4.59)% vs. (75.47±9.43)%, P < 0.05] through an decrease of Bcl-2/Bax ratio (grey value 0.63±0.20 vs. 0.77±0.12, P < 0.05). Compared with normal lung tissue, acute respiratory distress syndrome (ARDS) lung tissue markedly activate Hippo signaling in mMSCs [LATS1 protein (grey value) 1.71± 0.08 vs. 1.00±0.10, p-YAP/YAP protein ratio (grey value) 2.46±0.39 vs. 1.01±0.04, 14-3-3 protein (grey value)2.27±0.52 vs. 1.01±0.08, all P < 0.05]. Conclusion Hippo signaling could affect survival and capability of anti-oxidative stress of mMSCs via modulation of Bcl-2/Bax ratio in vitro.