Background：The phosphorylation ofp70S6 kinase （p70S6K） represents an important target for sensitive detection on pharmacodynamic effects of sirolimus,but the methods of assessing p70S6K phosphorylation are still un...Background：The phosphorylation ofp70S6 kinase （p70S6K） represents an important target for sensitive detection on pharmacodynamic effects of sirolimus,but the methods of assessing p70S6K phosphorylation are still unclear.The aim of this study was to investigate p70S6K phosphorylation located down-stream of the mammalian target ofrapamycin （mTOR） pathway in peripheral blood mononuclear cells （PBMCs） of liver transplant patients through different methods.Methods：Seventy-five liver transplant recipients from Beijing Chaoyang Hospital of the Capital Medical University were analyzed in this study.Patients were divided into three groups,patient treated with sirolimus （n =22）,patient treated with tacrolimus （n =30）,patient treated with cyclosporine （n =23）.The p70S6K phosphorylation of PBMCs in patients and healthy control （HC,n =12） were analyzed by phospho-flow cytometry and Western blotting.A correlation analysis of data from phospho-flow cytometry and Western blotting was performed.Intra-assay variability of p70S6K phosphorylation in HC and different patients were measured.Results：Intra-assay variability ofp70S6K phosphorylation in phospho-flow cytometry was from 4.1% to 8.4% and in Western blotting was from 8.2% to 18%.The p70S6K phosphorylation in patients receiving a sirolimus （19.5 ± 7.7） was significantly lower than in HC （50.1 ± 11.3,P 〈 0.001）,tacrolimus （37.7 ± 15.7,P 〈 0.001） or cyclosporine treated patients （41.7 ± 11.7,P 〈 0.001）.The p70S6K phosphorylation in HC （50.1± 11.3） was significantly higher than in tacrolimus （37.7 ± 15.7,P 〈 0.01） or cyclosporine-treated patients （41.7 ± 11.7,P 〈 0.01）.There was correlation between data from phospho-flow cytometry and data from Westem blotting （r =0.88,P 〈 0.001）.Conclusions：The degree of mTOR inhibition by assessing p70S6K phosphorylation was established by phospho-flow cytometry and Westem blotting.Assessment of p70S6K phosphorylation may play an adjunct role to on pharmacody展开更多
The peptide angiotensin IV(Ang IV)is a derivative of angiotensin II.While insulin regulated amino peptidase(IRAP)has been proposed as a potential receptor for Ang IV,the signalling pathways of Ang IV through IRAP rema...The peptide angiotensin IV(Ang IV)is a derivative of angiotensin II.While insulin regulated amino peptidase(IRAP)has been proposed as a potential receptor for Ang IV,the signalling pathways of Ang IV through IRAP remain elusive.We applied high-resolution mass spectrometry to perform a systemic quantitative phosphoproteome of Neura-2A(N2A)cells treated with and without Ang IV us-ing sta ble-isotope labeling by amino acids in cell culture(SILAC),and identifi ed a reduction in the phosphorylation of a major Ser/Thr protein phosphorylase 1(PP1)upon Ang IV treatment.In addition,spinophilin(spn),a PP1 reg-ulatory protein that plays important functions in the neural system,was expressed at higher levels.Immunoblotting revealed decreased phosphorylation of p70S6 kinase(p70S6K)and the major cell cycle modulator retinoblas-toma protein(pRB).These changes are consistent with an observed decrease in cell proliferation.Taken together,our study suggests that Ang IV functions via regulating the activity of PP1.展开更多
文摘Background：The phosphorylation ofp70S6 kinase （p70S6K） represents an important target for sensitive detection on pharmacodynamic effects of sirolimus,but the methods of assessing p70S6K phosphorylation are still unclear.The aim of this study was to investigate p70S6K phosphorylation located down-stream of the mammalian target ofrapamycin （mTOR） pathway in peripheral blood mononuclear cells （PBMCs） of liver transplant patients through different methods.Methods：Seventy-five liver transplant recipients from Beijing Chaoyang Hospital of the Capital Medical University were analyzed in this study.Patients were divided into three groups,patient treated with sirolimus （n =22）,patient treated with tacrolimus （n =30）,patient treated with cyclosporine （n =23）.The p70S6K phosphorylation of PBMCs in patients and healthy control （HC,n =12） were analyzed by phospho-flow cytometry and Western blotting.A correlation analysis of data from phospho-flow cytometry and Western blotting was performed.Intra-assay variability of p70S6K phosphorylation in HC and different patients were measured.Results：Intra-assay variability ofp70S6K phosphorylation in phospho-flow cytometry was from 4.1% to 8.4% and in Western blotting was from 8.2% to 18%.The p70S6K phosphorylation in patients receiving a sirolimus （19.5 ± 7.7） was significantly lower than in HC （50.1 ± 11.3,P 〈 0.001）,tacrolimus （37.7 ± 15.7,P 〈 0.001） or cyclosporine treated patients （41.7 ± 11.7,P 〈 0.001）.The p70S6K phosphorylation in HC （50.1± 11.3） was significantly higher than in tacrolimus （37.7 ± 15.7,P 〈 0.01） or cyclosporine-treated patients （41.7 ± 11.7,P 〈 0.01）.There was correlation between data from phospho-flow cytometry and data from Westem blotting （r =0.88,P 〈 0.001）.Conclusions：The degree of mTOR inhibition by assessing p70S6K phosphorylation was established by phospho-flow cytometry and Westem blotting.Assessment of p70S6K phosphorylation may play an adjunct role to on pharmacody
基金the Knowledge Innovation Project of the Chinese Academy of Sciences(KSCX1-YW-02)the National Natural Science Foundation of China(Grant No.30801416).
文摘The peptide angiotensin IV(Ang IV)is a derivative of angiotensin II.While insulin regulated amino peptidase(IRAP)has been proposed as a potential receptor for Ang IV,the signalling pathways of Ang IV through IRAP remain elusive.We applied high-resolution mass spectrometry to perform a systemic quantitative phosphoproteome of Neura-2A(N2A)cells treated with and without Ang IV us-ing sta ble-isotope labeling by amino acids in cell culture(SILAC),and identifi ed a reduction in the phosphorylation of a major Ser/Thr protein phosphorylase 1(PP1)upon Ang IV treatment.In addition,spinophilin(spn),a PP1 reg-ulatory protein that plays important functions in the neural system,was expressed at higher levels.Immunoblotting revealed decreased phosphorylation of p70S6 kinase(p70S6K)and the major cell cycle modulator retinoblas-toma protein(pRB).These changes are consistent with an observed decrease in cell proliferation.Taken together,our study suggests that Ang IV functions via regulating the activity of PP1.
