1.Advances of ubiquitin-conjugating pathway in eukaryotes
Chinese Journal of Pathophysiology 1986;0(02):-
A Review] A large quantity of intracellular structural and regulatory proteins can be covalently attached to ubiquitin posttranscriptionally and thus modified. The ubiquitination of proteins serves as targeting signals, making ubiquitinated proteins distributed to different parts of the cells, changing the activities, the interaction between macromolecules and the half-life of proteins. Therefore, ubiquitin conjugation is implicated in numerous metabolic processes in eukaryotes. Ubiquitin conjugates its protein substrates via a cascade reaction. This paper is a review of recent advances in this area.
2.Translesion Synthesis DNA Polymerase: A Novel DNA Polymerase
Progress in Biochemistry and Biophysics 2001;28(1):656-60
although there are many repair pathways in cells, some lesions still escape repair inevitably and remain in genome. In cells, the molecular mechanism of translesion DNA synthesis has been one of the major unsolved problems in DNA repair for a long time. Recently, it was found that the members of a structurally related UmuC/DinB protein superfarnily have DNA polyrnerase function. Unlike the classical replicative DNA polymerases, these newly identified DNA polymerases can carry out translesion DNA synthesis in both error prone/mutagenic and/or error-free ways. It was also found that their functions are conserved from bacteria to human.
3.The antisense block of CROC -1 gene expression makes cells grow slower
Jianming CHEN ; Yingnian YU ; Xingruo CHEN
Chinese Journal of Pathophysiology 2000;0(07):-
AIM:To establish FL- CROC -1 - cell line in which CROC -1 gene expression was blocked and study the role of CROC -1 gene in cell growth. METHODS:The appropriate length cDNA fragment of the recently identified human gene CROC -1 which encodes ubiquitin-conjugating enzyme like protein(Ubc-like protein) was cloned into the reconstructed eukaryotic expression vector pMAMneo-amp - by antisense strategy. The recombinant plasmid which can express CROC -1 antisense RNA was selected by restriction enzyme map analysis. The antisense expression recombinant plasmid pMAM-anti CROC -1 was then transfected into human amnion FL cells by a modified calcium phosphate-mediated transfection procedure and selected with MEM medium containing 400 ?g/mL geneticin. Finally ,the growth rate of the G418 resistant FL- CROC -1 - cell line was determined. RESULTS:When the antisense inhibition of CROC -1 gene expression was induced by dexamethasone, the growth rate of the FL- CROC -1 - cell line was obviously slower as compared with that of the control FL cell and FL-MAMneo cell which was established by transfection of plasmid pMAMneo-amp - ( P
4.Expression of phenylalanine ammonia-lyase cDNA from rice in E. coli BL21DE3
Zhunan CAI ; Yingnian YU ; Jianhong LUO ; Yuli QIAN ; Xiangruo CHEN
Chinese Journal of Pathophysiology 1986;0(01):-
AIM: To study the expression and its kinetics of rice phenylalanine ammonia-lyase gene encoding into E. coli as the basis of treatment for phenylketouria. METHODS: The phenylalanine ammonia-lyase-1-cDNA(rPAL-1-cDNA) from rice was recombined into E. coli high expression vector pET-28c and transformed into E. coli host strain BL21DE3. Engineering bacteria was then inducted by isopropyl-?-D-thiogalactoside (IPTG) for 1, 3, 5, 7 hours, in order to obtain high level expression. RESULTS: After induction, the expression level of fusion protein was 21.40%, 30.60%, 35.40%, 35.43% respectively. The fusion protein exhibited a band of 78 6 kD on SDS-PAGE analysis,but was not found in controls.The target protein was mainly existed in the form of inclusion body. CONCLUSION:Rice PAL gene expressing E. coli was established by gentic engineering technique.
5.Role of the Wnt/β-catenin signaling pathway in regulating the phenotypic transformation of aortic valvular myofibroblasts to osteoblast-like cells
Yingnian SHEN ; Hongjie WANG ; Di CHEN ; Gao XU ; Yongsheng LI
Chinese Journal of Geriatrics 2016;35(2):209-213
Objective To elucidate the role of the Wnt/-catenin signaling pathway in regulating the phenotypic transformation of aortic valvular myofibroblasts to osteoblast-like cells.Methods Cultured primary valvular myofibroblastes isolated from porcine aortic valve leaflets were treated with oxidized low-density lipoprotein (ox-LDL) for different lengths of time:24 h,48 h and 72 h.The Wnt signaling pathway inhibitor Dickkopf-1 (DDK-1) was co-incubated with ox-LDL for 72 h.After cells harvest,the expression of myofibroblastic or osteoblast-like phenotype related markers,a-smooth muscle actin (α-SMA),bone morphogenetic protein 2 (BMP2),alkaline phosphatase (ALP) and corebinding factora-1 (Cbfα 1),was detected by Western blotting.The expression and sub cellular localization of β3-catenin was assessed by immunocytochemistry.Changes of the Wnt/β-catenin signaling pathway and the transformation of aortic valvular myofibroblast to osteoblast-like cells were monitored.Results BMP2,ALP and Cbfa 1 protein expression was not or barely detectable in the control group.However,after ox-LDL treatment,the expression of α SMA,BMP2,ALP and Cbfa 1 increased significantly (each P<0.01) in a time-dependent manner (each P<0.05).Besides,ox-LDL was also able to up-regulate the protein expression of β-catenin in a time-dependent manner (P<0.05) and promoted its nuclear translocation.After DKK-1 treatment,the protein expression of β3 catenin and osteogenesis related markers was down regulated (P<0.05).Conclusions The Wnt/β-catenin signaling pathway may play a crucial role in regulating the transformation of aortic valvular myofibroblasts to an osteoblast like phenotype.
6.Effect of 5F from Pteris semipinnata on expression of Nr1d1 in HO-8910PM cell line.
Taiping HE ; Kefeng WU ; Yingnian LV ; Xianling GONG ; George Gong CHEN ; Nianci LIANG
China Journal of Chinese Materia Medica 2009;34(10):1268-1271
OBJECTIVETo investigate the effects of PsL5F (ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid, an extract from Pteris semipinnata L) on the expression of nuclear receptor subfamily 1, group D, member 1 (Nr1d1) in highly metastatic ovarian carcinoma HO-8910PM cells, and its mechanisms.
METHODMicroarray Chip was used to examine the level of Nr1d1 mRNA expression on HO-8910PM cells treated with PsL5F. Fluorescent quantitative real-time PCR assay and Western blot were performed to verify the effects of PsL5F on Nr1d1 mRNA and protein expression.
RESULTAfter 24 h treatment of 100 micromol x L(-1) PsL5F, the mRNA and protein levels of Nr1d1 in HO-8910PM cells were 35.34 +/- 1.07 and 7.71 +/- 0.43 times compared to those of control group (P < 0.01, P < 0.01), respectively.
CONCLUSIONPsL5F can up-regulate significantly the expression of Nr1d1 in HO-8910PM cells. Antitumor effects and its mechanisms of PsL5F in HO-8910PM cells may be involved in the up-regulation of Nr1d1 expression.
Antineoplastic Agents, Phytogenic ; pharmacology ; Cell Line, Tumor ; Drug Screening Assays, Antitumor ; Female ; Gene Expression ; drug effects ; Humans ; Neoplasm Invasiveness ; Ovarian Neoplasms ; pathology ; Piperidones ; pharmacology ; Pteris ; chemistry ; RNA, Messenger ; drug effects ; metabolism
7.ROS is not involved in induction of cell death by Ent-11 alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid in HepG2 cells.
Li LI ; Kefeng WU ; Yi LIU ; Yingnian LV ; Xianling GONG ; George G CHEN ; Paul LAI ; Nianci LIANG
China Journal of Chinese Materia Medica 2010;35(10):1287-1291
OBJECTIVETo identify the role of reactive oxygen species (ROS) formation on cell death induced by Ent-11alpha-hydroxy-15-oxo-kaur-16-en-19-oic-acid (5F) in HepG2 cells.
METHODMTT assay was used to determine the effect of 5F on proliferation of HepG2 cells, and apoptotic morphological changes were assessed using Hoechst/PI assay. To evaluate intracellular ROS levels, a GENMED kit was used. HepG2 cells were treated with 5F for 24 h or with 1 mmol x L(-1) GSH for 1 h prior to treatment with 5F for 24 h, then cytoplasmic mono- and oligonucleosomes were assessed with Cell Death Detection ELISA kit.
RESULTThe cytotoxicity of 5F on HepG2 cells was elevated with increasing 5F concentrations, as evidenced by the cell viability assay, and the apoptotic changes such as chromatin condensation were confirmed by Hoechst/PI staining. The decrease in ROS generation was observed in HepG2 cells following treatment with 5F. Cytoplasmic mono- and oligonucleosomes induced by 5F were not changed by decreasing basal level of ROS-mediated signaling with GSH. Further more, induction of ROS production by cisplatinum (CDDP) was canceled by treatment with 5F and 5F revealed a additive effect to cell killing by CDDP.
CONCLUSION5F can not only induce apoptosis through non-ROS-depandent pathway, and can abate oxidant stress.
Apoptosis ; drug effects ; Cell Death ; drug effects ; Diterpenes ; toxicity ; Drugs, Chinese Herbal ; toxicity ; Hep G2 Cells ; Humans ; Pteris ; chemistry ; Reactive Oxygen Species ; metabolism
8.Clinical study of the efficacies of ruxolitinib plus low-dose PTCY for acute GVHD prevention after haploidentical transplantation in malignant hematological diseases
Xiaoping LI ; Yu LI ; Lin LIU ; Zhongtao YUAN ; Youcheng WANG ; Yancheng DONG ; Dingsong ZHANG ; Jing FENG ; Yingnian CHEN ; Sanbin WANG
Chinese Journal of Hematology 2024;45(2):128-133
Objective:To investigate and verify a novel acute graft versus host disease (aGVHD) prevention protocol in the context of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) .Methods:Patients who underwent haplo-HSCT in our center between January 2022 and December 2022 were included. All patients received reduced doses of cyclophosphamide, Rabbit anti-human tymoglobulin, ruxolitinib, methotrexate, cyclosporine, and MMF to prevent aGVHD. The transplantation outcomes, complications, and survival rate of all patients were investigated.Results:A total of 52 patients with haplo-HSCT were enrolled, 29 (55.8%) male and 23 (44.2%) female, with a median age of 28 (5-59) years. There were 25 cases of acute myeloid leukemia, 17 cases of acute lymphocyte leukemia, 6 cases of myelodysplastic syndrome, 2 cases of chronic myeloid leukemia and 2 cases of myeloproliferative neoplasms. 98.1% of patients had successful engraftment. The incidence of Ⅱ-Ⅳ aGVHD and Ⅲ-Ⅳ aGVHD was 19.2% (95% CI 8.2% -30.3% ) and 7.7% (95% CI 0.2% -15.2% ), respectively. No patients experienced severe gastrointestinal mucositis. The Epstein-Barr virus and CMV reactivation rates were 40.4% and 21.3%, respectively. 9.6% of patients relapsed during followup, with 1-year overall survival, progression-free survival, and non-relapse mortality rates of 86.5% (95% CI 76.9% -96.1% ), 78.8% (95% CI 67.4% -90.3% ) and 11.5% (95% CI 2.6% –20.5% ), respectively. Conclusion:Ruxolitinib combined with a low dose of PTCY is a safe and effective first-line aGVHD prevention strategy.