Protective effect of metformin on pulmonary fibrosis caused by paraquat through activating AMP-activated protein kinase pathway / 中华危重病急救医学

OBJECTIVE@#To observe whether metformin (MET) inhibits transforming growth factor-β1 (TGF-β1)/Smad3 signaling pathway by activating adenosine activated protein kinase (AMPK), so as to alleviate the pulmonary fibrosis caused by paraquat (PQ) poisoning in mice.@*METHODS@#Male C57BL/6J mice were randomly divided into the Control group, PQ poisoning model group (PQ group), MET intervention group (PQ+MET group), AMPK agonist group (PQ+AICAR group), and AMPK inhibitor group (PQ+MET+CC group), according to a random number table method. A mouse model of PQ poisoning was established by one-time peritoneal injection of 1 mL PQ solution (20 mg/kg). The Control group was injected with the same volume of normal saline. After 2 hours of modeling, the PQ+MET group was given 2 mL of 200 mg/kg MET solution by gavage, the PQ+AICAR group was given 2 mL of 200 mg/kg AICAR solution by intraperitoneal injection, the PQ+MET+CC group was given 2 mL of 200 mg/kg MET solution by gavage and then 1 mL complex C (CC) solution (20 mg/kg) was intraperitoneally injected, the Control group and PQ group were given 2 mL of normal saline by gavage. The intervention was given once a day for 21 consecutive days. The 21-day survival rate of ten mice in each group was calculated, and the lung tissues of remaining mice were collected at 21 days after modeling. The pathological changes of lung tissues were observed under light microscope after hematoxylin-eosin (HE) staining and Masson staining, and the degree of pulmonary fibrosis was evaluated by Ashcroft score. The content of hydroxyproline in lung tissue and oxidative stress indicators such as malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), phosphorylated AMPK (p-AMPK), TGF-β1 and phosphorylated Smad3 (p-Smad3) in lung tissue were detected by Western blotting.@*RESULTS@#Compared with the Control group, the 21 days survival rate was significantly reduced, lung fibrosis and Ashcroft score were significantly increased in PQ group. In addition, the content of hydroxyproline, MDA and the protein expressions of α-SMA, TGF-β1 and p-Smad3 in lung tissue were significantly increased, while the activity of SOD and the protein expressions of E-cadherin and p-AMPK were significantly decreased in PQ group. Compared with the PQ group, the 21 days survival rates of mice were significantly improved in the PQ+MET group and PQ+AICAR group (70%, 60% vs. 20%, both P < 0.05). The degree of pulmonary fibrosis and the Ashcroft score were significantly reduced (1.50±0.55, 2.00±0.63 vs. 6.67±0.52, both P < 0.05). The content of hydroxyproline and MDA in lung tissue, as well as α-SMA, TGF-β1 and p-Smad3 protein expressions were significantly reduced [hydroxyproline (mg/L): 2.03±0.11, 3.00±0.85 vs. 4.92±0.65, MDA (kU/g): 2.06±1.48, 2.10±1.80 vs. 4.06±1.33, α-SMA/GAPDH: 0.23±0.06, 0.16±0.06 vs. 1.00±0.09, TGF-β1/GAPDH: 0.28±0.03, 0.53±0.05 vs. 0.92±0.06 p-Smad3/GAPDH: 0.52±0.04, 0.69±0.06 vs. 1.11±0.10, all P < 0.05], SOD activity and the protein expressions of E-cadherin and p-AMPK were significantly increased [SOD (μmol/g): 39.76±1.35, 33.03±1.28 vs. 20.08±1.79, E-cadherin/GAPDH: 0.91±0.08, 0.72±0.08 vs. 0.26±0.04, p-AMPK/GAPDH: 0.62±0.04, 0.60±0.01 vs. 0.20±0.04, all P < 0.05]. However, these protective effects of MET were inhibited by the addition of AMPK inhibitor CC solution.@*CONCLUSIONS@#MET can effectively alleviate the degree of pulmonary fibrosis in mice poisoned with PQ, and its mechanism may be related to the activation of AMPK and inhibition of TGF-β1/Smad3 signaling pathway, which can be inhibited by AMPK inhibitor CC.

Platelet-rich Plasma Induces M2 Macrophage Polarization via Regulating AMPK Singling Pathway / 中国实验血液学杂志

OBJECTIVE@#To investigate the role of platelet-rich plasma (PRP) in inducing the M2 macrophage polarization via regulating AMPK singling pathway.@*METHODS@#The expressions of M1 marker CD11c and M2 marker CD206 in macrophages of blank control group, LPS group, LPS+PRP group, and LPS+PRP+Compound C group were detected by flow cytometry. Western blot was used to observe the effects of PRP on the expression of AMPK-mTOR signaling pathway-related proteins at different times (12 h, 18 h and 24 h) after LPS treatment. RNA interference technology was used to silence the expression of AMPK in macrophages, and the expression of TGF-β protein was subsequently examined by Western blot.@*RESULTS@#LPS significantly reduced the expression of CD206 and increased the expression of CD11c (P <0.05). After the addition of PRP, the expression of CD206 was significantly increased (P <0.05), while the expression of CD11c was significantly decreased (P <0.05). Compared with LPS group, PRP treatment significantly increased the expressions of p-AMPK and p-ULK1 proteins at 12 h, 18 h and 24 h, while significantly decreased the expression of p-mTOR protein (P <0.05). After the addition of AMPK inhibitor Compound C, the expression of CD206 was significantly reduced (P <0.05) and the expression of CD11c was significantly increased compared with LPS+PRP group (P <0.05). After silencing the expression of AMPK in macrophages, the promotion effect of PRP on TGF-β was significantly reduced (P <0.05).@*CONCLUSION@#PRP can stimulate the transformation of macrophages to M2 type via AMPK signalling pathway.

Effect of γδ T cells on the Proliferation, Apoptosis and Autophagy of Multiple Myeloma Cells / 中国实验血液学杂志

AbstractObjective: To investigate the effect of γδ T cells on the proliferation, apoptosis and autophagy of multiple myeloma cells.@*METHODS@#Peripheral blood mononuclear cells (PBMNC) were isolated from healthy volunteers, and stimulated with zoledronic acid (Zol) in combination with rhIL-2. Flow cytometry analysis was used to detected the purity of γδ T cells. γδ T cells were collected and co-cultured with RPMI-8226 or U-266 cells at different effector target ratios. The proliferation of RPMI-8226 or U-266 cell lines were detected by CCK-8. Cell cycle and cell apoptosis were detected by flow cytometry and Western blot．The expressions of autophagy-related proteins were detected by Western blot.@*RESULTS@#γδ T cells can be expanded in vitro. γδ T cells could inhibit the proliferation of RPMI-8226 or U-266 cells, induced cell cycle arrest and promoted apoptosis in an effector target-dependent manner. In addition, γδ T cells could induce autophagy of myeloma cells, inhibited the expression of autophagy-related PI3K, P-AKT and P-mTOR, while increased the expression of AMPK and Beclin-1.@*CONCLUSION@#γδ T cells can inhibit the proliferation of RPMI-8226 and U-266 myeloma cells, induce cell cycle arrest, promote apoptosis, and enhance autophagy in vitro. The mechanism may be related to inhibition of PI3K/AKT/mTOR signaling pathway and/or activation of AMPK/Beclin-1 signaling pathway.