Neurofilaments (NFs) and cytokeratins are both heteropolymers, which assemble into intermediate filaments (IPs) only when other proper IF subunit proteins are expressed simultaneously. To study the assembly property o...Neurofilaments (NFs) and cytokeratins are both heteropolymers, which assemble into intermediate filaments (IPs) only when other proper IF subunit proteins are expressed simultaneously. To study the assembly property of NFs, we constructed two recombinant adenovirus which could express NF-L or NF-M, fused with green fluorescent protein (GFP) respectively. Then they were introduced into vero cells, and expressed fusion protein. Double labels of GFP fluorescence and immunofluorescence staining indicated that NF-L-GFP or GFP-NF-M not only coassembled with endogenous vimentins, but also coassembled with keratins into a cytoplasmic network of filaments.展开更多
Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cyc...Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.展开更多
Although previous studies showed that the principal oncoprotein encoded by Epstein-Barr virus, latent membrane protein 1 (LMP1), could induce the nasopharyngeal carcinoma cells in G2/M phase increased, littleis known ...Although previous studies showed that the principal oncoprotein encoded by Epstein-Barr virus, latent membrane protein 1 (LMP1), could induce the nasopharyngeal carcinoma cells in G2/M phase increased, littleis known about the target molecules and mechanisms. The present study demonstrated that LMP1 couldinduce the accumulation of p53 protein and upregulate its transactivity in a dose dependent manner, whichresulted in the decrease of the kinase activity of cdc2/cyclin B complex and inducing arrest at G2/M phasethrough the activation of NF-kB and AP-1 signaling pathways, and the effect of NF-kB was more obviousthan that of AP-1. This study provided some significant evidence for further elucidating the molecular mechanisms that LMP1 had effects on the surveillance mechanism of cell cycle and promoting the survivalof transformed cells and tumorigenesis.展开更多
To explore the impact of different concentrations of lanthanum chloride （LaC13） on critical components of wear particle-mediated signaling pathways in inflammation and osteoclastogenesis, RAW264.7 cells were natural...To explore the impact of different concentrations of lanthanum chloride （LaC13） on critical components of wear particle-mediated signaling pathways in inflammation and osteoclastogenesis, RAW264.7 cells were naturally divided into eight groups and analyzed by CCK-8 assay, flow cytometry, ELISA, RT-PCR and western blot after treatments. The results showed that three concentrations of LaCI3 had no influence on viability of RAW264.7 cells and down-regulated receptor activator of nuclear factor rd3 （RANK） instead of macrophage colony-stimulating factor receptor （M-CSFR）. Additionally, 2.5 and 10 pmol/L LaC13 could signifi- cantly inhibit gene and protein levels of pro-inflammatory cytokines （tumor necrosis factor-or and interleukin-113, i.e., TNF-ct and IL-113） and NF-r,B/p65, but 100 pmol/L LaC13 did not exert an obvious inflammation-inhibiting effect, and even induced inflamma- tion. In conclusion, these findings demonstrated that LaC13 was able to suppress wear particle-induced inflammation and activation of NF-rd3 in a certain range of concentrations in vitro and mainly decrease the expression of RANK, but not M-CSFR, all of which were generally recognized to play a pivotal role in osteoclastogenesis.展开更多
基金This work was supported by the National Science Found for Distinguished Young Scholars (Grant No. 39425009).
文摘Neurofilaments (NFs) and cytokeratins are both heteropolymers, which assemble into intermediate filaments (IPs) only when other proper IF subunit proteins are expressed simultaneously. To study the assembly property of NFs, we constructed two recombinant adenovirus which could express NF-L or NF-M, fused with green fluorescent protein (GFP) respectively. Then they were introduced into vero cells, and expressed fusion protein. Double labels of GFP fluorescence and immunofluorescence staining indicated that NF-L-GFP or GFP-NF-M not only coassembled with endogenous vimentins, but also coassembled with keratins into a cytoplasmic network of filaments.
基金supported by grants from the Chinese Ministry of Health (2012ZX10001006)the National Natural Science Foundation of China (81271812 and 31370182)+1 种基金111 Project (B08011)the Postgraduate Scholarship Program of the China Scholarship Council
文摘Viral protein R(Vpr) plays an important role in the replication and pathogenesis of Human immunodeficiency virus type 1(HIV-1). Some of the various functions attributed to Vpr, including the induction of G2/M cell cycle arrest, activating the NF-κB pathway, and promoting viral reverse transcription, might be interrelated. To test this hypothesis, a panel of Vpr mutants were investigated for their ability to induce G2/M arrest and to activate the NF-κB pathway. The results showed that the Vpr mutants that failed to activate NF-κB also lost the activity to induce G2/M arrest, which suggests that inducing G2/M arrest via Vpr depends at least partially on the activation of NF-κB. This latter possibility is supported by data showing that knocking down the key factors in the NF-κB pathway – p65, Rel B, IKKα, or IKKβ– partially rescued the G2/M arrest induced by Vpr.Our results suggest that the NF-κB pathway is probably involved in Vpr-induced G2/M cell cycle arrest.
文摘Although previous studies showed that the principal oncoprotein encoded by Epstein-Barr virus, latent membrane protein 1 (LMP1), could induce the nasopharyngeal carcinoma cells in G2/M phase increased, littleis known about the target molecules and mechanisms. The present study demonstrated that LMP1 couldinduce the accumulation of p53 protein and upregulate its transactivity in a dose dependent manner, whichresulted in the decrease of the kinase activity of cdc2/cyclin B complex and inducing arrest at G2/M phasethrough the activation of NF-kB and AP-1 signaling pathways, and the effect of NF-kB was more obviousthan that of AP-1. This study provided some significant evidence for further elucidating the molecular mechanisms that LMP1 had effects on the surveillance mechanism of cell cycle and promoting the survivalof transformed cells and tumorigenesis.
基金supported by National Natural Science Foundation of China(81160222)the Foundation of Health Department of Jiangxi Province(20121044)
文摘To explore the impact of different concentrations of lanthanum chloride （LaC13） on critical components of wear particle-mediated signaling pathways in inflammation and osteoclastogenesis, RAW264.7 cells were naturally divided into eight groups and analyzed by CCK-8 assay, flow cytometry, ELISA, RT-PCR and western blot after treatments. The results showed that three concentrations of LaCI3 had no influence on viability of RAW264.7 cells and down-regulated receptor activator of nuclear factor rd3 （RANK） instead of macrophage colony-stimulating factor receptor （M-CSFR）. Additionally, 2.5 and 10 pmol/L LaC13 could signifi- cantly inhibit gene and protein levels of pro-inflammatory cytokines （tumor necrosis factor-or and interleukin-113, i.e., TNF-ct and IL-113） and NF-r,B/p65, but 100 pmol/L LaC13 did not exert an obvious inflammation-inhibiting effect, and even induced inflamma- tion. In conclusion, these findings demonstrated that LaC13 was able to suppress wear particle-induced inflammation and activation of NF-rd3 in a certain range of concentrations in vitro and mainly decrease the expression of RANK, but not M-CSFR, all of which were generally recognized to play a pivotal role in osteoclastogenesis.
