T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and prolif...T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and proliferation are calciumdependent.A rise of cytoplasmic free Ca2+ quickly following activation with CD3 McAb is mainly due to intracellular mobilization of Ca2+,while lymphocyte proliferation needs both intracellular mobilization of Ca2+ as well as influx of extracellular Ca2+, It was confirmed that CTX sensitive G protein plays a role in regulating T cell proliferation by pretreatment with CTX suppressing lymphocyte H-TdR incorporation obviously.PLC and PKC inhibitor neomycin and P.S.S could also decrease T cell proliferation.展开更多
Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low e...Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low expression of the signal transducer and activator of transcription 3（STAT3） gene may promote the occurrence of neurodegenerative diseases to some extent. To clarify the roles of the NLRP3 inflammasome and STAT3 expression in oxidative stress,（1） SHSY5 Y cells were incubated with 1 mM H2 O2 to induce oxidative stress injury, and the expression of human-cell-specific signal transduction, STAT3-shRNA silencing signal transduction and STAT3 were detected. Cells were pretreated with Ca2＋ chelator BAPATA-AM（0.1 mM） for 30 minutes as a control.（2） Western blot assay was used to analyze the expression of caspase-1, NLRP3, signal transduction and STAT3. Enzyme-linked immunosorbent assay was used to analyze interleukin-1β levels. Flow cytometry was carried out to calculate the number of apoptotic cells. We found that H2 O2 treatment activated NLRP3 inflammasomes and decreased phosphorylation of signal transduction and STAT3 serine 727. BAPTA-AM pretreatment abolished the H2 O2-induced activation of NLRP3 inflammasomes, caspase-1 expression, interleukin-1β expression and apoptosis in SHSY5 Y cells, and had no effect in cells with downregulated STAT3 expression by RNAi. The findings suggest that downregulation of signal transduction and STAT3 expression may enhance the oxidative stress mediated by NLRP3, which may not depend on the Ca2^＋ signaling pathway.展开更多
The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be larg...The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.展开更多
文摘T cell activation and proliferation via CD3-TCR complex were investigated by lymphocyte DNA synthesis in vitro.Several interfering factors were also discussed.The result indicated that lymphocyte activation and proliferation are calciumdependent.A rise of cytoplasmic free Ca2+ quickly following activation with CD3 McAb is mainly due to intracellular mobilization of Ca2+,while lymphocyte proliferation needs both intracellular mobilization of Ca2+ as well as influx of extracellular Ca2+, It was confirmed that CTX sensitive G protein plays a role in regulating T cell proliferation by pretreatment with CTX suppressing lymphocyte H-TdR incorporation obviously.PLC and PKC inhibitor neomycin and P.S.S could also decrease T cell proliferation.
基金supported by Department of Science and Technology in Guizhou Province of China,No.Basic [2016]1131(to QianKe-He to HB)+2 种基金Department of Health and Family Planning Commission in Guizhou Province of China,No.2015-326(to HB)Less Developed Regions of the National Natural Science Foundation of China,No.81560482the Research Foundation for Creative Research Groups of Education Bureau of Guizhou Province of China,No.KY[2016]033(to QFZ)
文摘Activated nucleotide binding to the oligonucleotide receptor protein 3（NLRP3） inflammasome is possibly involved in the pathogenesis of Alzheimer＇s disease through oxidative stress and neurogenic inflammation. Low expression of the signal transducer and activator of transcription 3（STAT3） gene may promote the occurrence of neurodegenerative diseases to some extent. To clarify the roles of the NLRP3 inflammasome and STAT3 expression in oxidative stress,（1） SHSY5 Y cells were incubated with 1 mM H2 O2 to induce oxidative stress injury, and the expression of human-cell-specific signal transduction, STAT3-shRNA silencing signal transduction and STAT3 were detected. Cells were pretreated with Ca2＋ chelator BAPATA-AM（0.1 mM） for 30 minutes as a control.（2） Western blot assay was used to analyze the expression of caspase-1, NLRP3, signal transduction and STAT3. Enzyme-linked immunosorbent assay was used to analyze interleukin-1β levels. Flow cytometry was carried out to calculate the number of apoptotic cells. We found that H2 O2 treatment activated NLRP3 inflammasomes and decreased phosphorylation of signal transduction and STAT3 serine 727. BAPTA-AM pretreatment abolished the H2 O2-induced activation of NLRP3 inflammasomes, caspase-1 expression, interleukin-1β expression and apoptosis in SHSY5 Y cells, and had no effect in cells with downregulated STAT3 expression by RNAi. The findings suggest that downregulation of signal transduction and STAT3 expression may enhance the oxidative stress mediated by NLRP3, which may not depend on the Ca2^＋ signaling pathway.
文摘The native Goα was purified from bovine brain cortex and palmitoylated in vitro. The in vitro palmitoylation site was the same as that in vivo. The internal palmitoylation of purified native Goα was found to be largely maintained. The apparent palmitoylation ratio was significantly increased after the Goα was treated with DTT. The GTPγS binding characteristic of Goα was not influenced by palmitoylation, however, the affinity for LUVs was increased dramatically. The in vitro palmitoylation model of Goα provides a better basis for studying the functional role of G protein palmitoylation in signal transduction.
