Objective To explore the effect of the knockdown of transmembrane 9 superfamily protein member 2 (TM9SF2) on the replication of vesicular stomatitis virus (VSV), and investigate its role in the mechanism of antiviral innate immunity. Methods Small interfering RNA (siRNA) was used to knock down the TM9SF2 gene in human non-small cell lung cancer A549 cells. The CCK-8 method was used to assess cell proliferation. A VSV-green fluorescent protein (VSV-GFP) infected cell model was established. The plaque assay was used to measure the viral titer in the supernatant. RT-qPCR and Western blotting were employed to quantify the mRNA and protein levels of VSV genome replication in A549 cells following VSV infection, as well as the expression of interferon β (IFN-β) mRNA and interferon regulatory factor 3 (IRF3) protein phosphorylation following polyinosinic-polycytidylic acid (poly(I:C)) stimulation. Results Compared to the negative control, the knockdown of TM9SF2 exhibited a significant effect, with no observed impact on A549 cell proliferation. The VSV-GFP infected A549 cell model was successfully established. After viral stimulation, fluorescence intensity was reduced following TM9SF2 knockdown, and the mRNA and protein levels of VSV were significantly downregulated. The viral titer of VSV was decreased. After poly(I:C) stimulation, TM9SF2 knockdown significantly upregulated the mRNA level of IFN-β and the phosphorylation level of IRF3 protein. Conclusion The knockdown of TM9SF2 inhibits the replication of vesicular stomatitis virus, and positively regulates the type I interferon signaling pathway, thus enhancing the host's antiviral innate immune response.
Humans ; Virus Replication/genetics* ; Signal Transduction ; Membrane Proteins/metabolism* ; A549 Cells ; Vesiculovirus/physiology* ; Interferon-beta/metabolism* ; Interferon Regulatory Factor-3/genetics* ; Interferon Type I/metabolism* ; Vesicular Stomatitis/immunology* ; Gene Knockdown Techniques ; Vesicular stomatitis Indiana virus/physiology* ; RNA, Small Interfering/genetics*

OBJECTIVE To investigate the effect of eukaryotic translation elongation factor 1A1(eEF1A1)on the replication of vesicular stomatitis virus(VSV)and Herpes simplex virus 1(HSV-1)to identify a potential target for broad-spectrum regulation of viruses.METHODS Small interfering RNA(si-eEF1A)was transfected into human skin fibroblasts(BJ-5ta)to inhibit the expression of eEF1A1,and the negative control group was set up.The transfection efficiency was detected by real-time fluo-rescence quantitative PCR(RT-qPCR)and Western blotting,the cell model of eEF1A1 gene silencing was constructed.The cell model was infected with VSV,the gene copy number and protein expression of VSV in the cells were detected.The cell model was infected with HSV-1,the mRNA and protein expres-sion of HSV-1 in the cells were detected.The cell models were transfected with polyinosinic acid[Poly(I:C)]or sodium deoxyribonucleic acid(HT-DNA),respectively.The mRNA expression of interferon-β(IFN-β),C-X-C Motif Chemokine 10(CXCL10)and interferon-stimulated gene 56(ISG56)were detected by RT-qPCR.The phosphorylation expression of interferon regulatory factor 3(IRF3)and TANK binding kinase 1(TBK1)were detected by Western blotting.RESULT Compared with the negative control group,the mRNA and protein expression of eEF1A1 in the eEF1A1 gene silencing group were signifi-cantly decreased(P<0.01),the cell model of eEF1A1 gene silencing was successfully constructed.Compared with the negative control group,the VSV gene copy number of the eEF1A1 gene silencing group decreased by 70%-80%.The VSV protein expression decreased significantly(P<0.01).The mRNA expression of HSV-1 was decreased by 50%-60%,and the protein expression of HSV-1 was significantly decreased(P<0.01).After stimulation with Poly(I:C)or HT-DNA,compared with the negative control group.there was no significant difference in the mRNA expressions of IFN-β,ISG56 and CXCL10 and the protein phosphorylation expression of IRF3 and TBK1 in the eEF1A1 gene silencing group.CONCLUSION eEF1A1 silencing can inhibit VSV and HSV-1 virus replication,suggesting that eEF1A1 has a potential broad-spectrum regulatory effect on RNA viruses and DNA viruses,and may not recog-nize activated immune pathways through intracellular nucleic acid recognition.

Mutations of the X-linked methyl-CpG-binding protein 2 (MECP2) gene in humans are responsible for most cases of Rett syndrome (RTT), an X-linked progressive neurological disorder. While genome-wide screens in clinical trials have revealed several putative RTT-associated mutations in MECP2, their causal relevance regarding the functional regulation of MeCP2 at the etiologic sites at the protein level requires more evidence. In this study, we demonstrated that MeCP2 was dynamically modified by O-linked-β-N-acetylglucosamine (O-GlcNAc) at threonine 203 (T203), an etiologic site in RTT patients. Disruption of the O-GlcNAcylation of MeCP2 specifically at T203 impaired dendrite development and spine maturation in cultured hippocampal neurons, and disrupted neuronal migration, dendritic spine morphogenesis, and caused dysfunction of synaptic transmission in the developing and juvenile mouse cerebral cortex. Mechanistically, genetic disruption of O-GlcNAcylation at T203 on MeCP2 decreased the neuronal activity-induced induction of Bdnf transcription. Our study highlights the critical role of MeCP2 T203 O-GlcNAcylation in neural development and synaptic transmission potentially via brain-derived neurotrophic factor.
Animals ; Humans ; Methyl-CpG-Binding Protein 2/metabolism* ; Mice ; Neurodevelopmental Disorders/genetics* ; Rett Syndrome/genetics* ; Synaptic Transmission ; Threonine

The aim of this study was to investigate the effect of transmembrane 9 superfamily protein member 2 (TM9SF2) in proliferation and migration of triple negative breast cancer cell line MDA-MB-231.The expression of TM9SF2 in triple negative breast cancer cell line MDA-MB-231 and nontumorigenic mammary epithelial cell line MCF-10A were measured by Western blot. MDA-MB-231 cells were treated with siRNA-TM9SF2 to knock-down the expression of TM9SF2. The effect of silencing TM9SF2 was measured with Western blot.The proliferation of cells was tested by MTS,and the migration was measured with Transwell and wound-healing assay.Proteins related to proliferation (PI3K,AKT,SRC and ERK) and migration (Snail,Slug and N-cadherin) were measured with Western blot.Protein expressions of TM9SF2 was better improved in triple negative breast cancer MDA-MB-231 cell line than MCF-10A.Compared with the control group, the siRNA-TM9SF2 infected group had lower expressions of PI3K, Snail, Slug and N-cadherin, and at the same time phosphorylation of AKT was decreased. The results suggest TM9SF2 can promote the proliferation and metastasis of triple negative breast cancer MDA-MB-231 cell line.