ABSTRACT
Polyvinylidene fluoride (PVDF) has been widely studied and applied in separation membranes due to its high thermal and chemical stability and mechanical strength. However, PVDF has strong hydrophobicity, resulting in easy contamination of the membrane surface and fast flux attenuation, so it is necessary to modify the membrane surface to improve its separation selectivity and service life. In this paper, PVDF microporous membrane was used as the matrix material and graphene oxide (GO) as the separation layer material. The GO/Mn3O4/PVDF composite membrane was prepared by layer self-assembly of GO nanosheets, and the functional layer spacing was adjusted by nanometer Mn3O4 intercalation. The prepared composite membrane showed high flux and separation selectivity in the filtration of organic compounds. The results showed that the rejection of methylene blue increased from 34% to 99.5%, and the flux decreased from 3000 L m-2 h-1 to 95 L m-2 h-1 when GO nanosheets covered the PVDF supporting membrane. After the introduction of Mn3O4 nanowires in the GO interlayer, the dye rejection reached 99.9% and the flux reached 612 L m-2 h-1. Compared with the unintercalated composite membranes, the flux of the prepared composite membranes showed good stability in the treatment of methylene blue, and the rejection remained unchanged.
ABSTRACT
To investigate the effects of airway epithelial cells on macrophages chemotaxis and inflammatory cytokine expression under hypoxic conditions. Methods: Human bronchial epithelial cells (HBE) treated with different concentrations (0, 100, 200, 400, 800 μmol/L) of CoCl2 or transfected with HIF-1α siRNA were co-cultured with THP-1-derived M1 macrophages or M2 macrophages. The chemotactic effects on macrophages were analyzed by Transwell assay. The levels of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were detected by ELISA, and HIF-1α or Cav-1 mRNA expression in HBE or macrophages was detected by RT-qPCR. Results: HBE cells promoted macrophages chemotaxis in a time- and concentration-dependent manner. Compared to un-transfected group, the chemotactic ability of HBE transfected with HIF-1α siRNA was significantly weakened (P<0.01). Under the same culture conditions, the chemotaxis of M2 macrophages was greater than that in THP1-derived M1 macrophages. The concentrations of TNF-α, IFN-γ, IL-4, IL-13 and IL-10 in the supernatants of macrophages were increased in a time-and concentration-dependent manner. The concentrations of TNF-α and IFN-γ were increased further after co-culturing for 8 and 12 h; while IL-4, IL-13 and IL-10 concentrations were increased further during 24 h of co-culture. The levels of cytokines in the supernatants of macrophages co-cultured with HBE and transfected with HIF-1α siRNA were significantly lower than those in un-transfected cells (P<0.05 or P<0.01). The reduction of TNF-α or IFN-γ was more obvious. The expression of HIF-1α or Cav-1 mRNA in HBE or macrophages was increased in a concentration-dependent manner after 8 or 12 h co-culture, which was significantly reduced when HBE was transfected with HIF-1α siRNA. Conclusion: Airway epithelial cells can enhance macrophages chemotaxis and pro-inflammatory cytokines expressions under hypoxic condition. HIF-1α and Cav-1 may be the important mediators in these processes.
Subject(s)
Humans , Cell Hypoxia , Chemotaxis , Cytokines , Epithelial Cells , Hypoxia-Inducible Factor 1, alpha Subunit , MacrophagesABSTRACT
AIM: To explore the anticancer function of Shp2 in lung adenocarcinoma A549 cells and the related molecular mechanisms.METHODS: The viability and proliferation of A549 cells treated with Shp2 specific inhibi-tor Phps-1 or cisplatin (DDP) were measured by CCK-8 assay and EdU assay.Annexin V-FITC/PI double staining was ap-plied to detect apoptotic rate of A549 cells with different interventions.The protein levels of caspase-3-17p, Bcl-2, Bax, p-STAT3 /STAT3 and p-ERK/ERK were determined by Western blot.RESULTS: Compared with control group, Phps-1 at the concentration of 20 μmol/L significantly increased the viability of A549 cells after 24 h of treatment ( P <0.05). Meanwhile, the proliferation rate of A549 cells in Phps-1 20 μmol/L group was significant increased compared with control group (P <0.05).The apoptotic rate of A549 cells in DDP treatment group decreased from 13.01% ±2.62% to 3.67%±0.93% after adding Phps-1 (P <0.05).Phps-1 down-regulated the protein levels of caspase-3-17p, Bax and p-ERK, but up-regulated p-STAT3.CONCLUSION: Shp2 is a tumor suppressor in A549 cells, which may be associated with the activation of STAT3 signal pathway.
