Zhen-Yu Li

Xuzhou Medical College, Suchow, Jiangsu Sheng, China

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Publications (43)14.04 Total impact

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    ABSTRACT: Beta-catenin is a key regulator of leukemia stem cell maintenance and drug resistance. Herein, we investigated the protective effects of the stromal cell-mediated VE-cadherin-β-catenin signal on Ph+ leukemia cells during imatinib treatment. We found stromal cells could desensitize imatinib and up-regulate VE-cadherin expression on Ph+ leukemia cells (K562 and SUP-B15 cells), which further stabilized and activated β-catenin. Knockdown of VE-cadherin with shRNA diminished the β-catenin protein and partly resensitized Ph+ leukemia cells to imatinib despite the presence of stromal cells, suggesting VE-cadherin is a potential target in the treatment of Ph+ leukemia.
    Leukemia Research. 10/2014;
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    ABSTRACT: Arginine kinase (AK) is a key enzyme in cellular energy metabolism of invertebrates. There are two conserved amino acid residues D14 and R138 in dimeric AK which form inter-subunit hydrogen bond. In S. japonicus AK, mutations in these residues caused pronounced loss of activity, conformational changes and distinct substrate synergism alteration. Mutations (R138G, R138A and D14G) abolished D14 and R138 interaction disrupted the structure or conformation of S. japonicus AK. These R138G, R138A and D14G mutations changed their native assembles of dimeric AK and caused them in a partially unfolded state. The partially unfolded state of these mutant AKs made them prone to aggregate under environmental stress. The D14E/R138K and R138K mutant AKs showed similar characteristics to those of WT AK for forming the interaction which could replacement roles of D14 and R138 interaction. These results suggested that D14 and R138 interaction is involved in AK's activity, substrate synergism and structural stability.
    International journal of biological macromolecules 02/2014; · 2.37 Impact Factor
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    ABSTRACT: To explore gene expression of NANOG in T-cell acute lymphoblastic leukemia (T-ALL) cell lines and the effects of NANOG gene down-regulation on apoptosis of leukemia cells. Real-time PCR (RT-PCR) and Western blot were used to detect the expression level of NANOG gene and protein in MOLT-4, CCRF-HSB2 and Jurkat cells. To test the efficiency of RNA interference, MOLT-4 cells were firstly infected by lentiviral vectors, which were successfully constructed with NANOG specific shRNA. NANOG expression levels were subsequently re-evaluated by RT-PCR and Western blot. The percentages of early apoptotic cells (Annexin V⁺/7-AAD⁻) and late apoptotic cells (Annexin V⁺/7-AAD⁺) were analyzed by flow cytometry. The expression of apoptosis-related genes was also detected. Both NANOG gene and protein expression was positive in MOLT-4 and CCRF-HSB2 cells. The lentiviral vectors pLB-shNANOG-1, pLB-shNANOG-2, and pLB-shcontrol were successfully constructed, as evidenced by the viral titers (1.83-3.12)×10⁸ IU/ml. The experimental data on infection of MOLT-4 cells with such lentiviral vectors revealed that both shRNA interfering sequences (shNANOG-1 and shNANOG-2) could stably down-regulate NANOG gene and protein expressions. The percentages of early apoptotic cells in groups of shNANOG-1[(8.06±1.61)%]and shNANOG-2[(5.67±1.59)%]were significantly increased as compared to that of MOLT-4 group[(1.13±0.40)%]or sh-control [(1.15±0.49)%](P<0.05). However, no statistical difference among them was observed for late apoptotic cells (P>0.05). The gene expression of TP53, PMAIP1, and CASP9 of either shNANOG-1 or shNANOG-2 group was augmented as compared to that of MOLT-4 group or sh-control (P<0.05). Reversely, a significant down-regulation of Bcl-2 gene expression was observed (P<0.05). NANOG can be expressed in various human T-ALL cell lines. Down-regulation of NANOG can trigger leukemia cellular apoptosis through mitochondria-dependent apoptosis pathway.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 12/2013; 34(12):1001-5.
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    ABSTRACT: This study was purposed to explore the cellular source of IL-22 in graft versus host disease (GVHD) mouse following allo-geneic bone marrow transplantation. BALB/c and C57BL/6 mice were used as recipients and donors, respectively. GVHD model was established by irradiated BABL/c mice inoculated with mixed suspension of C57BL/6 bone marrow cells and splenic lymphocytes. The mice were divided into normal group(normal), total body irradiated group(TBI), bone marrow cell-transplanted group(BMT), and the combination of bone marrow cell and splenic lymphocytes-induced GVHD group(BS). The level of IL-22 in plasma was detected by ELISA. The cellular source of IL-22 and IL-22(+) subsets were detected by flow cytometry. The results showed that compared with normal mice, the level of IL-22 in plasma from BS mice was the highest(P < 0.01). All the lymphocytes of spleen, lymph nodes and peripheral blood from BS mice could produce IL-22, in which the percentage of IL-22(+)CD4(+) T cell was higher than that of IL-22(+)CD8(+) T cells. Not only Th22 cells but also Th1 and Th17 cells were the cellular source of IL-22 in GVHD mice. It is concluded that the high level of IL-22 has been found in mice with GVHD, which mainly originates from IFN-γ(-)IL-17(-)IL-22(+) Th22 cells.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 11/2013; 21(6):1526-9.
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    ABSTRACT: This study was aimed to investigate the effect of Wnt/β-catenin signaling pathway on the biologic behavior of mouse bone marrow mesenchymal stem cells(mBM-MSC) by constructing a RNAi lentiviral vector specific to β-catenin. Three pairs of shRNA coding sequences directed against different sites of β-catenin mRNA were designed and were linked into lentiviral vector plasmid PLB for constructing the PLB-β-catenin/shRNA1, PLB-β-catenin/shRNA2 and PLB-β-catenin/ shRNA3. Those plasimds and lentiviral packaging plasimds were co-transfected into the packaging cells 293FT, then the virus particles were collected and the viral titer was assayed after concentration, and these viral particles were infected to MSC. The flow cytometry was used to sort GFP (+)cells, Western blot and RT-PCR were used to verify the inhibitory effect of those cells on expression of β-catenin gene in cells, CCK-8 method was used to detect the cell proliferation level, Annexin-V/7-AAD was used to determine the cell apoptosis after interference, the cell scratch and transwell tests were used to detect the migration capalbility of MSC. The results showed that the efficient inhibition of β-catenin mRNA and protein expression, and the suppression of MSC proliferation were observed in group of PLB-β-catenin/shRNA2(inteference group), while there was no significant changes of MSC proliferation between negative group(PLB group) and the normal group (control group). The flow cytometric detection indicated that after induced by serum starvation for 72 h, the apoptosis of MSC increased in inteference group, but there was no difference between PLB and control groups(P > 0.05). The cell scratch and transwell tests demonstrated that the migration capability of MSC in inteference group dicreased significantly, while the migration capability of MSC in control group was not changed obvi-ously. It is concluded that the constructed specific RNAi lentivirus can effectively inhibit the expression of β-catenin gene, decrease expression level of β-catenin mRNA and protein. The Wnt/β-catenin signaling pathway plays an important role in biological behavior of BM-MSC.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 11/2013; 21(6):1546-51.
  • Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 09/2013; 34(9):804-806.
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    ABSTRACT: To investigate the effects of immature dendritic cells(imDC)expressing chemokine receptor-7(CCR7) on acute graft-versus-host disease(aGVHD) in allogeneic bone marrow transped (allo-BMT) mouse model. We constructed the lentiviral vectors carrying mouse CCR7 gene and infect imDC effectively in vitro. GVHD model was established with C57BL/6(H-2b)donor mice and BALB/c (H-2d) recipient mice. After irradiation, recipients were injected with donor bone marrow and spleen cells along with CCR7-modified dendritic cells. Mice were randomized into irradiation, transplant control, pXZ9-imDC(empty vector control) and CCR7-imDC groups. Survival, GVHD score, histopathological analysis and plasma levels of inflammatory cytokines were observed. The mean survival in irradiation, transplantation, pXZ9-imDC and CCR7-imDC groups were(8.20±1.48)d,(12.20±2.78)d, (20.70±6.01)d and (27.5±7.55)d respectively. The survival in CCR7- imDC group was significantly improved compared with other groups(P<0.05). GVHD scores in transplantation, pXZ9-imDC and CCR7-imDC groups were (6.90±1.66),(5.60±0.97) and (4.10±1.79) respectively. CCR7-imDC group had significantly lower GVHD score and minor tissue damages shown by histopathological analysis than the other groups. Plasma IFN-γ level increased and reached the peak at +10 day in transplant group, while it gradually decreased in pXZ9-imDC and CCR7-imDC groups, and then reached the nadir at +20 day post-allo-BMT, with the lowest level in CCR7-imDC group(P<0.01). Plasma IL-4 decreased in transplant group, while it gradually increased in pXZ9-imDC and CCR7-imDC groups and reached the highest level at + 10 day in CCR7- imDC group(P<0.01). The 95%-100% of H-2b positive cells in recipient mice on + 30 day post-allo-BMT demonstrated the complete donor- type implantation. Genetically modified immature DC by CCR7 gene could alleviate damages by GVHD and prolong survival of recipient mice after allo-BMT.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 09/2013; 34(9):782-787.
  • Yan-Jie Li, Zhen-Yu Li, Kai-Lin Xu
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    ABSTRACT: The studies in recent years have found that miRNA play an important role in various biological functions, such as cell differentiation, proliferation, apoptosis, migration, and survival. Many studies considered the abnormally expressed miRNA as significant regulator in the pathogenesis, progression and metastasis of malignant tumors. miRNA can funcion as oncogenes or tumor suppressors by regulating post-transcriptional factors effecting multi pathways and may even represent target for therapies. This review summarizes the current advancement about the roles of miRNA in the biology of multiple myeloma (MM), including focuses on miRNA signatures relevant to MM, functions of critical miRNA in the mechanisms and development of MM behind their deregulation, the role in the drug-resistance and perspective of their expression in MM.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 09/2013; 21(5):1318-25.
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    ABSTRACT: To investigate the sensitivity of imatinib mesylate (IM) on Sup-B15 Ph⁺ acute lymphoblastic leukemia (ALL) cells knockdown of VE-cadherin (CD144), and to further explore its mechanism. CD144 in Sup-B15 leukemia cells was stably knockdowned via lentivirus-mediated RNA interference (named as Sup-B15/shVEC). The inhibitory effects of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were measured by CCK-8 test, and the apoptosis of those cells was determined by AnnexinV/7-AAD dyeing using flow cytomery, the percentage of CD34⁺CD38⁻ leukemia cells also by flow cytomtery. ALDH1 mRNA levels were detected by real-time RT-PCR, and protein levels of CD144, CD133, Bcr-abl and β-catenin by Western blot. IM treatment presented inhibitory effects on Sup-B15/shVEC and Sup-B15 leukemia cells at multiple concentrations of IM. The IC50 of IM on Sup-B15/shVEC and Sup-B15 leukemia cells were 25.1μmol/L and 18.7μmol/L, respectively (P<0.05). After 48h of 20 μmol/L IM treatment, the percentages of apoptosis cell in Sup-B15/shVEC cells and Sup-B15 cell were (13.52±2.06)% and (3.03±0.72) %, respectively (P<0.05). The percentage of CD34⁺CD38⁻ cells in Sup-B15 cells was significantly higher than in Sup-B15/shVEC cells [(2.39±0.28)% vs (0.96±0.07)%, P<0.05). As compared to Sup-B15 cells, the transcription of ALDH1 in Sup-B15/shVEC was remarkably downregulated, and the CD133 protein level was also downregulated in Sup-B15/shVEC cells. Both cytoplamic and nucleic β-catenin protein levels (but not for Bcr-abl levels) decreased in Sup-B15/shVEC cells as compare to Sup-B15 cells. Knockdown of CD144 sensitized Sup-B15 Ph+ ALL cells to IM. The possible mechanisms underlying this phenomenon might be via inhibiting β-catenin nucleic translocation and facilitating β-catenin degradation.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 06/2013; 34(6):522-526.
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    ABSTRACT: To investigate the change of CD4⁺CD25(high)CD127(low) regulatory T cells (Tregs) percentage in patients with primary immune thrombocytopenia (ITP) treated by different methods. One hundred and thirty-eight newly diagnosed adult ITP patients (57 male, median age 40 years, range 18-70 years) were enrolled in this study, who were randomisedly separated into three regiment groups, namely prednisolone (PSL, 1.5 mg/kg for 2-4 weeks and subsequently stepwise reduction) group enrolled 49 patients, dexamethasone [(one course of high-dose dexamethasone (HDD) 40 mg/day, d1-4] 45 patients, and rituximab plus HDD (rituximab 100 mg on days 7, 14, 21, 28 and HDD) group 44 patients. Peripheral blood was taken in ITP patients of each group before treatment, 14 d and 28 d after treatment. The percentages of CD4⁺CD25(high)CD127(low) Tregs in 30 healthy controls and 138 patients were analyzed by flow cytometry. Overall response (OR) rates of PSL, HDD and R+HDD groups at day 28 were 69.4%, 66.7% and 79.5% respectively with no difference. After the following 12 months, sustained response (SR) was more pronounced in R+HDD group compared to the other two groups (R+HDD vs PSL: 66.7% vs 37.8%, P<0.05; R+HDD vs HDD: 66.7% vs 22.7%, P<0.05). The percentage of CD4⁺CD25(high)CD127(low) Tregs in peripheral blood of ITP patients [(1.67±0.70)%] was significantly lower than in healthy control group; After treatment, the percentages of Tregs in peripheral blood of patients both at day 14 and 28 in R+HDD group remarkably decreased compared with before treatment [(4.28±1.09)% vs (1.68±0.68)%, P<0.05; (4.44±0.63)% vs (1.68±0.68)%]. The percentages of Tregs at day 14 in both other two groups decreased notably compared with before treatment. But the Tregs levels measured at day 28 in PSL and HDD groups were similar with before treatment. The percentage of CD4⁺CD25(high)CD127(low) Tregs in peripheral blood of ITP patients was lower than healthy individual. The higher SR of patients treated by R+HDD was related to its ability to up-regulate the percentage of CD4⁺CD25(high)CD127(low) Tregs.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 06/2013; 34(6):478-481.
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    ABSTRACT: OBJECTIVE: To compare the efficacy and safety of low-dose rituximab combined with different dosage of glucocorticoids for immune thrombocytopenia (ITP). METHODS: Seventy-four patients (35 male, median age 34 years, range 18-70 years) including 60 newly-diagnosed, 6 persistent, 5 chronic and 3 refractory patients were enrolled in this study, and separated into control (36 cases) and experimental (38 cases) groups according to the dosage of glucocorticoids. Patients in both groups received dexamethasone 40 mg/day on days 1-4, followed by rituximab 100 mg on days 7, 14, 21, 28. The patients in experimental group also received decrements of prednisone 60, 30, 20, 10 mg/day on days 5-7, 8-14, 15-21, 22-28. The initial, long-term efficacy and safety were evaluated. RESULTS: Platelet counts of all patients at day 4 remarkably increased, with the median platelet count from 11(1-26)×10⁹/L to 84(23-132)×10⁹/L in control group, and 10(2-20)×10⁹/L to 80(22-115)×10⁹/L in experimental group;the platelet counts of patients at day 14 in experimental group [163(19-262)×10⁹/L] was higher than that of control group [98(18-238)×10⁹/L] (P<0.05). The overall response (OR) rates at day 28 in experimental group (84.21%) was significantly higher than that of control group (66.67%, P=0.03). There was no significant difference of sustained response (SR) rates in two groups (63.89%vs 65.79%, 58.33%vs 60.53%, P>0.05) at six and twelve months follow-up points. Both groups showed similar incidence of adverse events, and no patients discontinued the treatment due to side effects. CONCLUSION: Low-dose rituximab and glucocorticoids was an effective method for ITP patients, and maintenance treatment with decrements of prednisone contributed to improving earlier CR rate.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2013; 34(5):409-412.
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    ABSTRACT: OBJECTIVE: To construct mouse CXC chemokine receptor type 4 (Cxcr4) gene overexpressing lentiviral vector and to evaluate its biological effect on mouse mesenchymal stem cells (MSCs). METHODS: Cxcr4 gene was amplified and subcloned into pCR-Blunt vector. Cxcr4 gene and enhanced green fluorescent protein (EGFP) gene expressed bicistronic recombinant lentiviral vector LV-CXCR4-IRES-EGFP and control vector LV-IRES-EGFP were constructed, respectively. Both plasmids were co-transfected into 293FT packaging cell line with packaging plasmid pSPAX2 and enveloping plasmid pMD.2G using Lipofectamine 2000 to produce lentiviral virus, respectively. The recombinant viruses were harvested and the virus titer was determined by limiting dilution. Mouse MSCs were infected with viral supernatant. EGFP expression was visualized using fluorescence microscope and efficiency of infection was determined by flow cytometry (FCM). Cell counting kit-8 (CCK-8) was applied in mixed lymphocyte reaction (MLR) to evaluate the suppressive effect of MSCs on mice splenocyte proliferation in vitro. Wound healing ability of MSCs was measured by scratch experiment and migration capacity by a chemotaxis assay using a transwell assay. RESULTS: The Cxcr4 fragment was amplified by reverse transcription polymerase chain reaction (RT-PCR) and verified by DNA sequencing. The restriction enzyme digestion experiment demonstrated that the recombinant lentiviral vector LV-CXCR4-IRES-EGFP and the control vector LV-IRES-EGFP were successfully constructed. Expression of CXCR4 was detected by fluorescence microscopy, which indicated that the lentiviral particles expressing CXCR4 were packaged. Furthermore,expression of EGFP were detected by fluorescence microscopy in MSCs after infection and the expression of CXCR4 protein on MSCs surface in CXCR4-MSC group was significantly increased comparing to those in the control group(P<0.05).CXCR4-MSCs group and the control group were (90.3±3.37)% and (1.53±0.34)%, respectively. Meanwhile, overexpression of CXCR4 had no effect on their capacity of immune regulation when co-cultured with splenocyte(P>0.05). Moreover, overexpression of CXCR4 can not only accelerated the wound healing after scratch, but also enhanced the migration ability of cells in the transwell induced by high concentration of SDF-1 in a dose-dependent manner compared with the EGFP control group. CONCLUSION: The CXCR4 expressing lentiviral vector LV-CXCR4-IRES-EGFP was successfully constructed. The lentiviral vector can not only efficiently infect mouse MSCs, but also stably express CXCR4 in MSCs. The MSCs modified with CXCR4 have biological characteristic in vitro.
    Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 05/2013; 34(5):440-444.
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    ABSTRACT: This study was aimed to construct the targeting AATF shRNA eukaryotic expression vector and establish the stably transfected U937 cell lines. The sequence of AATF mRNA was obtained from GenBank. After excluding homeology, three plasmid expression vectors coding shRNA targeting 228 ∼ 249, 303 ∼ 324 and 443 ∼ 464 of AATF gene sequence were synthesized. Two terminals of shRNA carried BamHI and HindIII restriction sites. The selected nucleotides were cloned into the plasmid pSilencer 3.1-H1 neo respectively, and the resultant recombinant plasmids were named as pSA-1, pSA-2, pSA-3. The sequences of the recombinant plasmids were identified by DNA sequencing. The recombinant plasmids were transfected into the cell line U937 by electroporation with Neon(TM) Transfection System. The transfected cells were persistently screened under G418 (500 mg/L), and isolated with a limited dilution for 8 weeks. The inhibition of AATF mRNA and protein expression was respectively detected by RT-PCR and Western blot. The results indicated that RNAi eukaryotic expression vectors targeting AATF had correct reading frame and nucleotide sequence. Real-time PCR revealed that AATF shRNA effectively silenced mRNA expression of AATF. Western blot analysis found that AATF shRNA obviously suppressed protein expression of AATF (P < 0.05). It is concluded that the shRNA eukaryotic expression vector has been successfully constucted which can inhibit the expression of AATF, and the establishment of stably transfected U937 cell lines provide a original route for exploring the mechanism of AATF in human Leukemia further.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 05/2013; 21(3):567-570.
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    ABSTRACT: This study was purposed to investigate the B7-H3 expression in multiple myeloma cell lines and CD138 cells of patients with multiple myeloma, and explore its clinical significance. Three myeloma cell lines (RPMI8226, U266 and H929) were used. Forty-five patients with multiple myeloma were enrolled in the study. The expression of B7-H3 was detected by flow cytometry and RT-PCR. The relationship between B7-H3 and clinical prognostic factor was analyzed. The results showed that (1)In myeloma cell lines, high expression of B7-H3 was seen in RPMI8226 (92.30 ± 1.1)% and U266 (79.03 ± 1.2)% but not in H929 cell line (4.26 ± 0.2)%. (2) Exogenous IL-6 had no effect on upregulation of B7-H3 in myeloma cell lines. (3) In multiple myeloma patients, the proportions of B7-H3 positive cells in newly diagnosed, remission and relapsed patients were (48.58 ± 33.593)%, (22.16 ± 18.853)%, and (57.65 ± 28.296)%, respectively. The difference between the newly diagnosed and remission patients, and remission and relapsed patients was significant (P = 0.023, P = 0.004). (4)High B7-H3 expression was correlated with high numbers of bone destruction and high levels of serum calcium (P = 0.027, P = 0.046, respectively). It is concluded that the relation of B7-H3 molecule expression with prognosis of multiple myeloma may be negative, but with degree of bone destuction is positive, thus the high expression of B7-H3 may correlated with disease progression and bone destruction of patients with multiple myeloma.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 05/2013; 21(3):637-642.
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    ABSTRACT: Homeobox genes encode the class of transcription factors in vertebrates and are found in clusters called A, B, C, and D on four separate chromosomes. HOXA9 gene is part of the cluster A on chromosome 7 and encodes a DNA-binding transcription factor which may regulate gene expression, morphogenesis, and differentiation. The objective of this study was to determine the HOXA9 gene expression in acute myeloid leukemia (AML). For this purpose, semi-quantitative reverse transcriptase-polymerase chain reaction was used to measure HOXA9 gene expression in human erythroleukemia (HEL) cell line and bone marrow mononuclear cells from 54 AML patients and 20 healthy individuals. The data show that HOXA9 mRNA expression was negative in 20 healthy individuals but was positive in HEL cells and in 22 out of 54 (40.74 %) AML patients. The complete remission rate (45.45 %) of the patients who expressed the gene was significantly lower than that (71.86 %) in patients who did not express the gene after chemotherapy. Therefore, it was concluded that HOXA9 gene might be involved in the pathogenesis of AML and played as a worse prognostic factor in AML.
    Cell biochemistry and biophysics 04/2013; · 3.34 Impact Factor
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    ABSTRACT: Abstract Janus kinase 2 (JAK2) is an important mediator of cytokine receptors signaling and plays key roles in the hematopoietic and immune responses. The acquired JAK2 R683G (S) somatic mutations are detected in 15% of B-cell acute lymphoblastic leukemia (B-ALL) patients and presumed to be a biomarker for B-ALL. However, how JAK2 R683G (S) mutations caused B-ALL is still unclear. Our results indicated that the E627 and R683 interaction played vital roles in JAK2 auto-inhibition. Mutations (R683S, R683G and E627A) disrupting this interaction led to JAK2 constitutive activation. While, mutations (R683K, E627D) restoring this interaction decreased its activity. Furthermore, spectroscopic experiments implied that disruption of the E627 and R683 interaction abolished the JH1/JH2 domains interactions and forced JH1 domain into the open, active conformation. Mutations abolishing this interaction promoted the proliferation of Ba/F3 cells. These results herein may provide clues in understanding the mechanism of JAK2 R683G (S) mutations caused B-ALL.
    Leukemia & lymphoma 03/2013; · 2.61 Impact Factor
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    ABSTRACT: Creatine kinase (CK) is a key enzyme for cellular energy metabolism, catalyzing the reversible phosphoryl transfer from phosphocreatine to ADP in vertebrates. Due to its important physiological functions, the acquired CK somatic mutations are closely correlated to diseases. In this study, the E79G point mutation was identified in two acute myocardial infarction patients with muscle CK activity deficiency. The crystal structure of CK indicates that the E79 and K138 interaction plays key roles in sustaining the recognition between N- terminal and C-terminal domains. Mutations of these residues caused pronounced loss of activity, conformational changes and distinct substrate synergism alteration. Moreover, spectroscopic spectra experiments suggested that mutations disrupting this hydrogen bond impaired the secondary and tertiary structure of CK. Meanwhile, protein folding experiments implied that mutations lead them to the partially unfolded state which made them easier to be inactivated and unfolded under environmental stresses. Furthermore, this partially unfolded state upon environmental stresses might gradually decrease the CK level in the patients. Thus, these results might provide clues in the mechanism of CK deficiency diseases.
    International journal of biological macromolecules 12/2012; · 2.37 Impact Factor
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    ABSTRACT: The aim of this study was to detect the expression of interleukin-22 (IL-22) and relative CD4(+) T cell subsets in untreated adult patients with immune thrombocytopenia (ITP), and to explore their roles in the pathogenesis of ITP. Fourty adult active ITP patients were enrolled in this study and 40 healthy subjects were taken as control. Plasma IL-22 level was quantified by ELISA. The percentages of Th1, Th17 and Th22 cells in peripheral blood were determined by flow cytometry. The Pearson correlation test was used to evaluate correlations between IL-22 level and Th1 cells, Th17 cells and Th22 cell percentages. The results showed that the plasma IL-22 levels in untreated ITP patients [(364.12 ± 94.22) pg/ml] were significantly higher than that in healthy controls (P < 0.001). The percentages of both Th1 [(18.92 ± 6.03)%] and Th22 [(2.28 ± 0.51)%] cells in ITP patients were elevated as compared to healthy controls (P < 0.05). Elevated plasma concentration of IL-22 positively correlated to the percentages of Th1 (r = 0.42, P = 0.022) and Th22 (r = 0.40, P = 0.030) cells in untreated ITP patients. The percentage of Th17 cells was not significantly different between untreated patients and normal controls, and there was no statistical correlation between the IL-22 level and the percentage of Th17 cells in active ITP patients. It is concluded that elevated IL-22 level correlates to Th1 and Th22 cells percentage, which may play a synergistic effect in the immunopathogenesis of ITP, while Thl7 cells may not be associated with the occurence of active ITP.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 11/2012; 20(6):1432-5.
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    ABSTRACT: Janus kinase 2 (JAK2) is an important mediator of cytokine receptor signaling and plays a key role in the hematopoietic and immune responses. The acquired JAK2 C618R somatic mutation is detected in a subset of myeloproliferative disorders (MPDs) patients and presumed to be a biomarker for MPDs. However, how JAK2 C618R mutation causes MPDs is still unclear. Our results indicate that the amino acid residue E543 in JAK2 C618R is indispensable for its constitutive activation. When the glutamic acid at this position was mutated to alanine (E543A) in the JAK2 C618R, its activity significantly decreased. However when the glutamic acid was mutated to the acidic amino acid, aspartic acid, JAK2 C618R activity changed little. These results suggest that there is an interaction between the amino acid residue R618 and E543, and that this interaction is crucial to sustain the constitutive activation of JAK2 C618R. More importantly, the E543 single mutation had no effects on the function of wild type JAK2 (WT JAK2). This study suggests that the amino acid residue E543 might be a potential target for specific inhibitors to treat MPDs caused by the JAK2 C618R mutation.
    Archives of Biochemistry and Biophysics 08/2012; 528(1):57-66. · 3.37 Impact Factor
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    ABSTRACT: This study was aimed to propagate and identify the prdm1 gene-knockouted mice, so as to lay the foundation for studying Blimp-1 protein. Two kinds of transgenic homozygous mice with B6.prdm1(flox/flox) and B6.Lck-Cre were feeded and propagated; after succesful propagating, the first passage mice were obtained; after the first passage mice were copulated once again, the genotypes were obtained as follows: B6. prdm1(wild/wild). Lck-Cre, B6. prdm1(wild/wild), B6.prdm1(flox/flox). Lck-Cre, B6.prdm1(flox/wild). Lck-Cre, B6.prdm1(flox/flox), B6. prdm1(flox/wild). The genomic DNA of second passage mice was extracted, the Cre and loxp gene fragments were amplified by PCR, then the size of Cre and loxp genomic DNA were detected by agarose gel electrophoresis. The mice with B6.prdm1(flow/flox). Lek-Cre were used as conditionally prdm1-knockouted mice, B6.prdm1(flox/wild). Lck-Cre mice, B6.prdm1(flox/flox) and B6 mice were used as controls. The spleen T lymphocytes and B lymphocytes were sorted by using magnetic beads, the blimp-1 target protein was identified by Western blot. The results showed that the two trensgenetic homozygous mice had the ability to reproduce, and the separation ratio of second passage mice generated from propagation of their offspring cach other meet Mendelian laws, and the prdm1 gene-knockouted mice also could successfully obtained. It is concluded that the application of Cre-loxp system may successfully obtain plentiful prdm1 gene-knockouted mice.
    Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology 07/2012; 20(4):985-8.