[The Effect of Matrix Remodeling Associated 7 (MXRA7) Expression on the Biological Function of SHI-1 Cells].

OBJECTIVE: To express matrix remodeling associated 7 (MXRA7) in the human acute myeloid leukemia SHI-1 cell line and to assess the role of MXRA7 in the biological function of SHI-1 cells. METHODS: The full-length cDNA sequence of human MXRA7 was synthesized and subcloned into the lentivirus shuttle vector pRRL-Venus. SHI-1 cells were transfected with the lentivirus which was packaged with 293T cells. The YFP-positive cells were sorted by flow cytometry and the stable cell lines were obtained by expanded culture. The expression and distribution of MXRA7 in SHI-1 cells were verified by real-time qPCR, Western blot and laser confocal techniques. Cell proliferation and cell cycle were measured by flow cytometry, and apoptosis was determined by Annexin V and 7-AAD staining. The expression of apoptosis related proteins were detected by Western blot. RESULTS: The stable SHI-1 cell line overexpressing MXRA7 was established successfully. Laser confocal analysis confirmed that MXRA7 was expressed in the cytoplasm of SHI-1 cells. Compared with the control cell line, the overexpression of MXRA7 showed no effect on the cell proliferation and cell cycle, but reduced the percentage of apoptosis cells induced by methotrexate. Moreover, the expression of BCL-2 protein was increased by overexpression of MXRA7, which can inhibit cell apoptosis. CONCLUSION: The SHI-1 stable cell line overexpressing MXRA7 was established successfully, and MXRA7 could inhibit drug-induced apoptosis through increasing the expression of BCL-2 protein.

Nuclear Factor-κB Signaling Mediates Antimony-induced Astrocyte Activation.

OBJECTIVE: Antimony (Sb) has recently been identified as a novel nerve poison, although the cellular and molecular mechanisms underlying its neurotoxicity remain unclear. This study aimed to assess the effects of the nuclear factor kappa B (NF-κB) signaling pathway on antimony-induced astrocyte activation. METHODS: Protein expression levels were detected by Western blotting. Immunofluorescence, cytoplasmic and nuclear fractions separation were used to assess the distribution of p65. The expression of protein in brain tissue sections was detected by immunohistochemistry. The levels of mRNAs were detected by Quantitative real-time polymerase chain reaction (qRT-PCR) and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Antimony exposure triggered astrocyte proliferation and increased the expression of two critical protein markers of reactive astrogliosis, inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP), indicating that antimony induced astrocyte activation in vivo and in vitro. Antimony exposure consistently upregulated the expression of inflammatory factors. Moreover, it induced the NF-κB signaling, indicated by increased p65 phosphorylation and translocation to the nucleus. NF-κB inhibition effectively attenuated antimony-induced astrocyte activation. Furthermore, antimony phosphorylated TGF-ß-activated kinase 1 (TAK1), while TAK1 inhibition alleviated antimony-induced p65 phosphorylation and subsequent astrocyte activation. CONCLUSION: Antimony activated astrocytes by activating the NF-κB signaling pathway.