Expression, purification, and functional verification of recombinant human glycoprotein hormone beta 5/alpha 2 fusion protein in CHO-S cells / 中国药理学通报

Aim To express and purify recombinant hCGH-CTP fusion protein in high-density suspension culture of Chinese hamster ovary cells (CHO-S), and to verify the lipid accumulation effect of rhCGH-CTP on 3T3-L1 mature adipocytes. Methods The recombinant protein expression vector (pcDNA3. 1-rhCGH-CTP) was constructed, achieved by fusing the human glycoprotein hormone beta 5/alpha 2 cDNA with CTP Linker. The expression plasmid was transiently transfected into the suspended CHO-S to express rhCGH-CTP protein and then purified, and the protein biological activity was verified. Intervention with 3T3-L1 mature adipocyte cells for 24 h was performed to detect the changes of intracellular triglyceride (TG) level. Results Western blot results showed that rhCGH-CTP protein was successfully expressed in CHO-S cells, and the yield was up to 715. 4 mg • L~ . The secreted protein was purified by AKTA pure system with higher purity that was up to 90% as identified by SDS-PAGE. In addition, the intracellular cAMP content of mature adipocytes with high expression of TSHR gene significantly increased after intervention with different concentrations of rhCGH-CTP protein by ELISA kit, indicating that rhCGH-CTP protein had biological activity. Oil red 0 staining showed that compared with the control group, the lipid content of mature adipocytes in the intervention groups with different concentrations of rhCGH-CTP protein significantly decreased (P < 0. 05) . Conclusions The rhCGH-CTP protein has been successfully expressed and purified with biological activity, and effectively reduce TG. This research provides an important theoretical basis for further revealing the physiological role of CGH protein and its potential application in clinical practice.

Effect of low concentration of sodium fluoride on osteogenic/odontogenic differentiation of human dental pulp cells / 口腔疾病防治

Objective@#To study the effect of low concentrations of sodium fluoride on the osteogenic/odontogenic differentiation of human dental pulp cells (hDPCs) in vitro.@*Methods@#This study was reviewed and approved by the Ethics Committee. hDPCs were cultured using a modified tissue explant technique in vitro. The effects of different concentrations of sodium fluoride on the proliferation of hDPCs were measured by methylthiazol tetrazolium (MTT) assay. Appropriate concentrations were added to the osteogenic/odontogenic differentiation induction medium, and the cells were induced in vitro. Alizarin red S staining was used to detect the osteoblastic/odontogenic differentiation ability of the cells, and the mRNA expression of the key differentiation factors was detected by RT-qPCR. Moreover, the expression of key molecules of endoplasmic reticulum stress (ERS) was detected by RT-qPCR and Western blot. The data were analyzed with the SPSS 18.0 software package.@*Results@#Low concentration of NaF (0.1 mmol/L) could stimulate cell proliferation in vitro, while a high concentration (5-10 mmol/L) could inhibit cell proliferation (P<0.05). According to the literature and the experimental data, 0.1 mmol/L NaF was selected as the following experimental concentration. The levels of alizarin red S staining were increased after NaF induction of mixed osteogenic/odontogenic differentiation in vitro. The mRNA expression levels of key molecules for osteogenic/odontogenic differentiation, dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP) and osteocalcin (OCN), were increased (P<0.05). The mRNA levels of ERS markers (splicing x-box binding protein-1 (sXBP1), glucose-regulated protein 78 (GRP78) and activating transcription Factor 4 (ATF4) were increased in NaF-treated cells. The protein expression levels of key ER stress molecules (phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-PERK), phosphorylated eukaryotic initiation factor-2α (p-eIF2α) and ATF4) were higher in NaF-treated cells.@*Conclusion@#A low concentration of NaF promotes the osteogenic/odontogenic differentiation of hDPCs and increases the level of ER stress.

Evaluation of biological activity of an eukaryotic expressed anti-H5N1-M1 cell entry single molecule antibody / 中国生物制品学杂志

@#Objective To evaluate the biological activity of a eukaryotic expressed anti-H5N1-M1 cell entry single molecule antibody(TAT-ScFv-mFc). Methods The immune binding activity and affinity of TAT-ScFv-mFc to H5N1-M1 protein were detected by Western blot and localized surface plasmon resonance(LSPR)respectively;The inhibitory effect of TAT-ScFv-mFc on influenza virus H1N1 was detected by CCK-8 assay;The membrane penetration ability of TAT-ScFv-mFc to MDCK cells was verified by immunofluorescence assay. A total of 30 female BALB/c mice were injected with TAT-ScFv-mFc via tail vein,200 μL per mouse. Blood samples were collected at 5,60,120,240 and 360 min after injection. Serum samples were separated and detected for the titers by ELISA,and the half-life of TAT-ScFv-mFc was calculated according to the half-life curve drawn by Origin 2021 software. Results TAT-ScFv-mFc showed specific binding to H5N1-M1 protein with a binding rate constant of 6. 67 × 10~4[1/（M*s）]. The survival rate of MDCK cells infected by H1N1 increased gradually with the increase of TAT-ScFv-mFc concentration in a dose-dependent manner,which obviously inhibited the replication of H1N1. TAT-ScFv-mFc penetrated the cell membrane of MDCK cells in a short time,entered the cell and bound to virus M1protein,thus inhibiting virus replication and assembly. The half-life of TAT-ScFv-mFc in mice was 212 min. Conclusion TAT-ScFv-mFc has good immune binding activity and affinity with H5N1-M1,can effectively inhibit the replication of H1N1,has good penetration ability to MDCK cell membrane,and has a long half-life in mice,which lays a foundation of the drug treatment,vaccine research and preventive treatment of H5N1 infection.

Construction of eukaryotic expression plasmid of human promyelocytic leukemia gene of six transcripts and subcellular location analysis of its recombinant proteins / 中国生物制品学杂志

@#Objective To construct eukaryotic expression plasmids of human promyelocytic leukaemia(hPML) gene of six transcripts and analyze the subcellular location of the recombinant proteins.Methods Primers were designed according to the hPML gene sequences registered in GenBank databases.Six transcripts of hPML gene fragments(hPML Ⅰ,Ⅱ,Ⅳ,Ⅴ,Ⅵ and Ⅶ) were amplified by RT-PCR,which were linked to the eukaryotic expression vector pCAGGS respectively.The obtained eukaryotic expression plasmids of six transcripts of hPML gene were transfected into 293T cells respectively and detected for their protein expression by Western blot,while transfected into Vero cells and detected for their subcellular location by indirect immunofluorescence assay(IFA).Results The target gene fragments of the six eukaryotic expression plasmids were consistent with the hPML gene sequences registered in GenBank.All the six recombinant proteins showed specific binding with Myc antibody,among which the recombinant protein hPML Ⅰ,Ⅱ,Ⅳ,Ⅴ and Ⅵ were located in the nucleus and cytoplasm,while the recombinant protein hPML Ⅶ was mainly located in the cytoplasm,rarely in the nucleus.Conclusion The eukaryotic expression plasmids of six transcripts of hPML gene all can be expressed correctly in mammalian cells,and the expressed recombinant proteins were located in nucleus and cytoplasm simultaneously or mainly in cytoplasm.This study provides an experimental basis for subsequent study on the antiviral and other biological functions of recombinant protein hPML.

Expressions of eukaryotic initiation factor-4B and eukaryotic initiation factor-5A in papillary thyroid carcinoma and their effects on cell proliferation in vitro / 肿瘤研究与临床

Objective:To investigate the expressions of eukaryotic initiation factor-4B (eIF4B) and eukaryotic initiation factor-5A (eIF5A) in papillary thyroid carcinoma tissues, and to analyze their regulatory effects on cell proliferation in vitro.Methods:The clinical data of 61 patients diagnosed with papillary thyroid carcinoma who received surgical resection at Yuncheng Central Hospital from January 2020 to October 2021 were retrospectively analyzed. The postoperative tumor tissues and paracancerous normal thyroid tissues (>1 cm from the margin of the mass) were retained. Immunohistochemistry was used to detect the expressions of eIF4B, eIF5A and proliferating cell nuclear antigen (PCNA) in different tissues. The correlation of eIF4B, eIF5A expressions with the clinicopathological characteristics of patients, and the relationship between eIF4B, eIF5A and PCNA were analyzed. The thyroid cancer cell line SW1736 and normal thyroid cell line HT-ori3 were selected. The expressions of eIF4B mRNA and eIF5A mRNA were detected by using real-ime quantitative polymerase chain reaction (qRT-PCR). After the small interfering RNA (siRNA) of siRNA-eIF4B and siRNA-eIF5A were synthesized, the interfering plasmids were constructed, and SW1736 cells were transfected, siRNA-eIF4B group and siRNA-eIF5A group were obtained; the empty plasmid transfection group and the blank control group without transfection intervention were established. The cell proliferation activity was detected by using CCK-8 assay, and the expression of PCNA mRNA was detected by using qRT-PCR.Results:The positive rates of eIF4B and eIF5A in papillary thyroid cancer tissues were higher than those in paracancerous normal thyroid tissues [65.57% (40/61) vs. 29.51% (18/61), 57.38% (35/61) vs. 9.84% (6/61), P < 0.001]. The positive rates of eIF4B and eIF5A were statistically different in patients with different tumor diameter [>3 cm vs. ≤3 cm: 88.89% (16/18) vs. 55.81% (24/43),77.78% (14/18) vs. 48.84% (21/43), all P < 0.05], lymph node metastasis [with vs. without: 85.00% (17/20) vs. 56.10% (23/41), 80.00% (16/20) vs. 46.34% (19/41), all P < 0.05] and the number of different nodes [multiple vs. single: 86.67% (13/15) vs. 58.70% (27/46), 86.67% (13/15) vs. 47.83% (22/46), all P < 0.05]; there were no statistically significant differences in the positive rates of eIF4B and eIF5A among patients with different age and gender (all P > 0.05). Positive correlation was found between eIF4B score and the positive cell proportion of PCNA ( r = 0.66, P = 0.0324), eIF5A score and the positive cell proportion of PCNA ( r = 0.62, P = 0.024), eIF4B score and eIF5A score ( r = 0.63, P = 0.021). The expression levels of eIF4B mRNA and eIF5A mRNA in thyroid cancer cell line SW1736 cell was higher than that of HT-ori3 cell in normal thyroid (all P < 0.05). The cell proliferation activity of SW1736 and PCNA mRNA expression level in siRNA-eIF4B group and siRNA-eIF5A group were lower than those in the empty vector transfected group and the blank control group (all P < 0.05). Conclusions:eIF4B and eIF5A are expressed elevated in papillary thyroid carcinoma, and both are involved in tumor development and progression. The role of eIF4B and eIF5A may be related to promoting the proliferation of tumor cells.

Eukaryotic expression and biological activity identification of fusion protein ABD-Fc-IL-2 / 中国生物制品学杂志

@#Objective To express the fusion protein ABD-Fc-IL-2 in eukaryotic cells and detect its biological activity. Methods The target gene SP-ABD-Fc-IL-2 was amplified by direct and overlapping PCR,and then ligated to vector pcDNA3. 1(+).The obtained recombinant plasmid pcDNA3. 1/SP-ABD-Fc-IL-2 was transiently transfected into CHO-S cells to express the fusion protein ABD-Fc-IL-2,which was purified by Protein A beads affinity chromatography. The specificity of the purified fusion protein was detected by Western blot,the biological activity was detected by CTLL-2/MTT cell proliferation colourimetry,and the interaction between ABD fragment and human serum albumin(HSA)was detected by pull down/Western blot. Results The recombinant plasmid pcDNA3. 1/SP-ABD-Fc-IL-2 was constructed correctly as identified by restriction analysis and sequencing. The purified fusion protein ABD-Fc-IL-2 showed a purity of 90% and bound specifically to mouse anti-IL-2 monoclonal antibody with the biological activity of 3. 29 × 108IU/mL. The ABD of fusion protein and HSA bound to each other. Conclusion The eukaryotic fusion protein ABD-Fc-IL-2 had high biological activity,which promoted the proliferation of CTLL-2 cells and maintained the binding ability of ABD fragment to HSA.

Role of Eukaryotic Translation Elongation Factor 1 Family Members in the Tumorigenesis and Progression of Lung Adenocarcinoma / 中国医学科学院学报

Objective To investigate the role and mechanism of eukaryotic translation elongation factor 1(EEF1) family members (EEF1D,EEF1A1,and EEF1A2) in lung adenocarcinoma (LUAD) based on public databases.Methods We examined EEF1 member expression levels in human LUAD samples via The Cancer Genome Atlas in the UCSC Xena browser and the Clinical Proteomic Tumor Analysis Consortium.We analyzed the mRNA and protein levels of EEF1D,EEF1A1,and EEF1A2 and their correlations with pathological variables via the Mann-Whitney U test.The Kaplan-Meier curves were established to assess the prognostic values of EEF1D,EEF1A1,and EEF1A2.The single-sample gene set enrichment analysis algorithm was employed to explore the relationship between the expression levels of EEF1 members and tumor immune cell infiltration.Spearman and Pearson correlation analyses were performed to examine the relationship between the expression levels of EEF1 members and those of the genes in the phosphatidylinositol 3-kinase/protein kinase B signaling pathway.The immunohistochemical assay was employed to determine the expression levels of EEF1D,EEF1A1,and EEF1A2 in the LUAD tissue (n=75) and paracancer tissue (n=75) samples.Results The mRNA and protein levels of EEF1D,EEF1A1,and EEF1A2 showed significant differences between tumor and paracancer tissues (all P<0.001).The patients with high protein levels of EEF1A1 showed bad prognosis in terms of overall survival (P=0.039),and those with high protein levels of EEF1A2 showed good prognosis in terms of overall survival (P=0.012).The influence of the mRNA level of EEF1D on prognosis was associated with pathological characteristics.The expression levels of EEF1 members were significantly associated with the infiltration of various immune cells and the expression of key molecules in the phosphatidylinositol 3-kinase/protein kinase B signaling pathway.Conclusion EEF1D,EEF1A1,and EEF1A2 are associated with the progression of LUAD,serving as the candidate prognostic markers for LUAD.

Bovine viral diarrhea virus Erns protein expressed in Chinese hamster ovary cells and its immunogenicity analysis / 生物工程学报

The aim of this study was to produce Erns protein of bovine viral diarrhea virus (BVDV) by using suspensively cultured CHO cells expression system and to analyze the immunogenicity of the purified Erns protein. In this study, the recombinant eukaryotic expression plasmid pcDNA3.1-BVDV-Erns was constructed based on the gene sequence of BVDV-1 NADL strain. The Erns protein was secreted and expressed in cells supernatant after transfecting the recombinant expression plasmid pcDNA3.1-BVDV-Erns into CHO cells. The expression and purification of the Erns protein was analyzed by SDS-PAGE, the reactivity was determined with anti-His monoclonal antibodies and BVDV positive serum with Western blotting. Immunogenicity analysis of the Erns protein was determined after immunizing New Zealand white rabbits, and the serum antibodies were tested by indirect ELISA (iELISA) and indirect immunofluorescence (IFA). The serum neutralizing titer of the immunized rabbits was determined by virus neutralization test. The concentration of the purified Erns protein was up to 0.886 mg/mL by BCA protein quantification kit. The results showed that the Erns protein could be detected with anti-His monoclonal antibodies and anti-BVDV sera. Serum antibodies could be detected by iELISA on the 7th day post-prime immunization, and the antibody level was maintained at a high titer until the 28th day post-immunization. The antibody titer was 1:128 000. Furthermore, the expression of the Erns protein in BVDV-infected MDBK cells could be detected with immunized rabbits sera by IFA. Moreover, antigen-specific neutralizing antibodies of 2.71 log10 was induced in rabbits. In this study, purified BVDV Erns protein was successfully produced using CHO suspension culture system, and the recombinant protein was proved to have a good immunogenicity, which may facilitate the development of BVD diagnosis method and novel subunit vaccine.

Construction and expression of the eukaryotic expression vector of wild-type p27 and lacking the nuclear localization signal p27 / 西安交通大学学报(医学版)

【Objective】 To construct the eukaryotic expression vector carrying the human wild-type p27 and lacking nuclear localization signal p27△NLS coding sequences， and the express them in HEK293T cells， which may contribute to investigating the different locations and roles of p27 in the cytoplasm and nucleus. 【Methods】 Total RNA was prepared from human breast cancer MCF7 cells， and cDNA was obtained by reverse transcription-polymerase chain reaction （RT-PCR）. After amplification of the p27 CDs and non-NLS fragments by PCR， full length p27WT （CDKN1B， NM_004064.5） and p27△NLS coding regions were obtained. PCR products were then subcloned into the eukaryotic expression vector pCMV-Blank. After identification with bacterial PCR， double restriction enzyme digestion and sequencing， they were defined officially as pCMV-p27WT and pCMV-p27△NLS， respectively. The recombinant plasmids were transfected into HEK293T cells by electroporation. After 48 h， the levels of p27 protein in the cytoplasm and nucleus were detected by Western blotting. 【Results】 The sequencing results showed that the sequences of p27WT and p27△NLS inserted into the plasmids were both correctly consistent with that of NM_004064.5. After transfection with pCMV-p27WT， total p27 protein expression was increased and distributed in both the cytoplasm and nucleus of HEK293T cells. After transfection with pCMV-p27△NLS， p27 protein was significantly increased and almost entirely localized in the cytoplasm of HEK293T cells. 【Conclusion】 The eukaryotic expression plasmids of human p27WT and p27△NLS coding sequences were successfully constructed and overexpressed in HEK293T cells. This research may lay a foundation for investigating the biological function of p27 in the cell cycle progression of tumor cells.

Eukaryotic expression and antigen epitope prediction of the LRRC15 protein in excretory secretory antigens of Taenia solium cysticercus / 中国血吸虫病防治杂志

OBJECTIVE@#To conduct eukaryotic expression of the leucine-rich repeat containing 15 (LRRC15), a differentially expressed protein in excretory secretory antigens of Taenia solium cysticercus, and predict its antigen epitope.@*METHODS@#The molecular weight, stability, amino acid sequence composition, isoelectric point and T lymphocyte epitope of the LRRC15 protein were predicted using the bioinformatics online softwares ExPASy-PortParam and Protean. The full-length splicing primers were designed using PCR-based accurate synthesis, and the LRRC15 gene was synthesized. The recombinant pcDNA3.4-LRRC15 plasmid was constructed and transfected into HEK293 cells to express the LRRC15 protein. In addition, the LRRC15 protein was characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting.@*RESULTS@#The recombinant pcDNA3.4-LRRC15 plasmid was successfully constructed, which expressed the target LRRC15 protein with an approximately molecular weight of 70 kDa. Bioinformatics prediction with the ExPASy-PortParam software showed that LRRC15 was a hydrophilic protein, which was consisted of 644 amino acids and had a molecular weight of 69.89 kDa and an isoelectric point of 5.6. The molecular formula of the LRRC15 protein was C3073H4942N846O953S28 and had an instability coefficient is 50.3, indicating that LRRC15 was an instable protein. Bioinformatics prediction with the Protean software showed that the dominant T-cell antigen epitopes were located in 292 to 295, 353 to 361, 521 to 526 and 555 to 564 amino acids of the LRRC15 protein, and the T-cell antigen epitopes with a high hydrophilicity, good flexibility, high surface accessibility and high antigenicity index were found in 122 to 131, 216 to 233, 249 to 254, 333 to 343, 358 to 361, 368 to 372, 384 to 386, 407 to 412, 445 to 450, 469 to 481, 553 to 564, 588 to 594, 607 to 617 and 624 to 639 amino acids. Following transfection of the recombinant pcDNA3.4-LRRC15 plasmid into HEK293 cells, SDS-PAGE and Western blotting identified LRRC15 proteins in cell secretory culture media, cell lysis supernatants and sediments. The LRRC15-His fusion protein was purified from the cell culture medium, and SDS-PAGE identified a remarkable band at approximately 70 kDa, while Western blotting successfully recognized the band of the recombinant LRRC15 protein.@*CONCLUSIONS@#The eukaryotic expression and antigen epitope prediction of the LRRC15 protein in the excretory secretory antigens of T. solium cysticercus have been successfully performed, which provides insights into further understandings of its biological functions.

Therapeutic effects of IL-6 and BAFF fusion protein eukaryotic expression plasmid on animal model of Sj?gren′s syndrome / 中华微生物学和免疫学杂志

Objective:To investigate the effects of a eukaryotic expression plasmid for IL-6 and B-cell activating factor (BAFF) fusion protein on the histopathological changes in salivary and lacrimal glands of non-obese diabetic (NOD) mice with Sj?gren′s syndrome and to elucidate the possible therapeutic mechanism of IL-6/BAFF fusion protein eukaryotic expression plasmid in NOD mice.Methods:The eukaryotic expression plasmid for IL-6/BAFF fusion protein was constructed. After transfecting CHO cells with the plasmid, the expression of IL-6/BAFF fusion protein was detected by Western blot. BALB/c mice were injected with the plasmid every two weeks for three times and the titers of anti-IL-6 and anti-BAFF antibodies were measured by ELISA. Twenty-one NOD mice were randomly divided into three groups (control group, empty vector group and therapy group) by numerical table method. The mice in the therapy group were injected with the IL-6/BAFF fusion protein eukaryotic expression plasmid once a week for six times and the mice in the empty vector group were injected with empty plasmid. The levels of anti-IL-6 and anti-BAFF antibodies as well as cytokines (IL-6, BAFF, INF-γ, IL-10 and IL-17A) in mouse serum samples were detected by ELISA. The proportions of Th17, Treg, Th1 and Th2 cells in mouse splenocytes were measured by flow cytometry. Focal lymphocyte infiltration and pathological changes in the lacrimal and salivary glands of mice were observed under light microscopy after HE staining.Results:The eukaryotic expression plasmid for IL-6/BAFF fusion protein increased the levels of anti-IL-6 and anti-BAFF antibodies in the serum of BALB/c mice ( P<0.05). The levels of anti-IL-6 and anti-BAFF antibodies in the serum of NOD mice in the therapy group increased ( P<0.01), while the expression of IL-6, BAFF, INF-γ, IL-10 and IL-17A in NOD mice in the therapy group was lower than that in the control group and the empty vector group ( P<0.05). The percentages of Treg and Th2 cells in the splenocytes of NOD mice increased after treatment ( P<0.05). Moreover, the eukaryotic expression plasmid for IL-6/BAFF fusion protein significantly improved the irregular size and morphology of glandular vesicles in the lacrimal and salivary glands, reduced the ductal dilatation and decreased the focal lymphocyte infiltration in NOD mice. Conclusions:The eukaryotic expression plasmid for IL-6/BAFF fusion protein induced the production of anti-IL-6 and anti-BAFF antibodies, decreased the expression of inflammatory cytokines, regulated the balance of Th17/Treg and Th1/Th2 cells, improved the irregular alveolar structure and ductal dilation in the lacrimal and salivary glands and reduced the focal lymphocyte infiltration in NOD mice. This study showed that eukaryotic expression plasmid for IL-6/BAFF fusion protein might serve as a potential target for therapeutic targeting of T and B cells.

The proliferation promoting effect of eIF2α on fibroblasts of rheumatoid arthritis synovium / 中华风湿病学杂志

Objective:To observe the expression characteristics of eukaryotic translation initiation factor 2α(eIF2α), and analyze its proliferation regulation effect on fibroblasts of rheumatoid arthritis synovium.Methods:The synovial tissues were collected in patients with rheumatoid arthritis(RA)(40 cases) and osteoarthritis(OA)(40 cases). EIF2α and proliferating cell nuclear antigen(PCNA) were detected by immunohistochemistry method. Fibroblast cell line of rheumatoid arthritis synovium(MH7A) were cultured to establish si-eIF2α group(siRNA-eIF2α plasmid transfection), vector transfection group and blank control group in vitro. PCNA was detected by Western blot method, cell proliferation activity was detected by CCK-8 method. χ2 test was performed on count data, two-sample t-test was performed on quantitative data, one-way analysis of variance (ANOVA) was performed to compare the means of more than two groups, regression equation was calculated by correlation regression analysis. Results:The positive rate of eIF2α was significantly higher in RA synovial fibroblasts than that of OA [52.5%(21/4) vs 20.00%(8/20), χ2=9.14, P=0.003]. Positive correlation was found between eIF2α and PCNA in RA ( Y=0.366 X+2.220, P=0.001) . Compared with blank control group and vector transfection group, cell proliferation activity decreased significantly in si-eIF2α group of MH7A cell line at 72 h [(0.65±0.08) vs (0.96±0.12) vs (1.09±0.06), F=4.52, P=0.022] and 96 h [(1.13±0.14) vs (1.42±0.97) vs (1.56±0.12), F=9.87, P=0.001) , PCNA expression decreased significantly [(0.84±0.15) vs (1.32±0.18) vs (1.28±0.14), F=5.22, P=0.012) . Conclusion:High expression of eIF2α can promote the proliferation of fibroblasts of RA synovium.

Study of endoplasmic reticulum stress in human dental pulp cells induced by oxygen-glucose deprivation culture in vitro / 口腔疾病防治

Objective@#Oxygen-glucose deprivation (OGD) is used to mimic ischemia in vitro to observe whether endoplasmic reticulum (ER) stress is involved in human dental pulp cells (hDPCs) after OGD and to better understand the regulatory mechanism of hDPCs in ischemia.@*Methods@# hDPCs were cultured in glucose-free DMEM and hypoxia (volume fraction 2% O2) to establish an hDPCs OGD model in vitro, which mimics hDPCs ischemia in vitro. hDPCs were divided into a control group (normal culture) and an experimental group (OGD 0 h, 2 h, 4 h and 8 h groups). After pretreatment with OGD for 0, 2, 4 and 8 h, hDPC viability was measured by methylthiazol tetrazolium (MTT) assay. qRT-PCR was used to detect the mRNA expression of ER stress markers [splicing x-box binding protein1 (sXBP1), activating transcription Factor 4 (ATF4) and C/EBP homologous protein (chop)]. Western blot was used to detect the protein expression of ER stress markers [phosphorylated RNA-activated protein kinase-like ER-resident kinase (p-perk) and phosphorylated eukaryotic initiation factor-2α (p-eIF2α)]. @*Results@#Compared with OGD 0 h group, cell viability of hDPCs decreased when exposed to OGD treatment for 2 h, 4 h and 8 h. Compared with the control group, mRNA expressions of ER stress makers (sXBP1, ATF4 and chop) and the protein expressions of ER stress protein markers (p-perk andp-eIF2α) increased in OGD treatment cells after 4 h were higher in OGD cells. The differences were statistically significant (P<0.05).@*Conclusion@#The results indicate that ER stress response is involved in hDPCs in OGD treatment.

Identification and expression analysis of WRKY gene family in eukaryotic algae / 生物工程学报

WRKY is a superfamily of plant-specific transcription factors, playing a critical regulatory role in multiple biological processes such as plant growth and development, metabolism, and responses to biotic and abiotic stresses. Although WRKY genes have been characterized in a variety of higher plants, little is known about them in eukaryotic algae, which are close to higher plants in evolution. To fully characterize algal WRKY family members, we carried out multiple sequence alignment, phylogenetic analysis, and conserved domain prediction to identify the WRKY genes in the genomes of 30 algal species. A total of 24 WRKY members were identified in Chlorophyta, whereas no WRKY member was detected in Rhodophyta, Glaucophyta, or Bacillariophyta. The 24 WRKY members were classified into Ⅰ, Ⅱa, Ⅱb and R groups, with a conserved heptapeptide domain WRKYGQ(E/A/H/N)K and a zinc finger motif C-X4-5-C-X22-23-H-X-H. Haematococcus pluvialis, a high producer of natural astaxanthin, contained two WRKY members (HaeWRKY-1 and HaeWRKY-2). Furthermore, the coding sequences of HaeWRKY-1 and HaeWRKY-2 genes were cloned and then inserted into prokaryotic expression vector. The recombinant vectors were induced to express in Escherichia coli BL21(DE3) cells and the fusion proteins were purified by Ni-NTA affinity chromatography. HaeWRKY-1 had significantly higher expression level than HaeWRKY-2 in H. pluvialis cultured under normal conditions. High light stress significantly up-regulated the expression of HaeWRKY-1 while down-regulated that of HaeWRKY-2. The promoters of HaeWRKY genes contained multiple cis-elements responsive to light, ethylene, ABA, and stresses. Particularly, the promoter of HaeWRKY-2 contained no W-box specific for WRKY binding. However, the W-box was detected in the promoters of HaeWRKY-1 and the key enzyme genes HaeBKT (β-carotene ketolase) and HaePSY (phytoene synthase) responsible for astaxanthin biosynthesis. Considering these findings and the research progress in the related fields, we hypothesized that the low expression of HaeWRKY-2 under high light stress may lead to the up-regulation of HaeWRKY-1 expression. HaeWRKY-1 may then up-regulate the expression of the key genes (HaeBKT, HaePSY, etc.) for astaxanthin biosynthesis, consequently promoting astaxanthin enrichment in algal cells. The findings provide new insights into further analysis of the regulatory mechanism of astaxanthin biosynthesis and high light stress response of H. pluvialis.

DNA Damage-Inducible Transcript 4 (Ddit4) Overexpression Could Inhibit Proliferation and Promote Apoptosis of HT-22 Cells through the Wnt / β-catenin Signaling Pathway / 中国生物化学与分子生物学报

Neural tube defects (NTDs) are congenital defect diseases caused by cell proliferation and apoptosis disorders. Using RNA-Seq assays, we found the increased expression of DNA damage-inducible transcript 4 (Ddit4) in embryonic brain tissues from NTD fetuses. In this study, we intend to explore the effects of Ddit4 overexpression on the proliferation and apoptosis of HT-22 cells and related mechanisms to lay the foundation for the study of the role of Ddit4 in NTDs. According to the mouse Ddit4 sequence, we constructed the eukaryotic expression vector pEX-3-Ddit4. The results of restriction enzyme analysis and sequencing showed that the eukaryotic expression vector pEX-3-Ddit4 was successfully constructed. qRT-PCR and Western blotting results showed that the expression level of Ddit4 in HT-22 cells was significantly increased after transfection of PEX-3-Ddit4 (P < 0. 01) . CCK-8 and Western blotting results showed that Ddit4 overexpression decreased the proliferation of HT-22 cells (P < 0. 01) . Flow cytometry showed that Ddit4 overexpression increased the proportion of cells in the G

Expression and localization of Copine-3-enhanced green fluorescent protein fusion protein / 解剖学报

Objective To construct the eukaryotic expression vector plasmid enhanced green fluorescent protein (pEGFP)-N1-CPNE3, and identify the expression and localization of Copine-3 protein in cells. Methods The Copine-3 coding sequences (CPNE3) was amplified by RT-PCR from human bronchial epithelial (HBE) cells and inserted into eukaryotic expression vector pEGFP-Nl. The recombinant plasmid pEGFP-Nl-CPNE3 was confirmed by endonuclease digestion and sequencing before it was transfected into 293T and H1299 cells. Cellular localization of Copine-3-EGFP fusion protein was detected by con-focal laser scanning. Expression of Copine-3 in 293T and H1299 cells was detected by Western blotting analysis. Localization of Copine-3 in clinical samples of the lung adenocarcinoma patients was detected by immunohistochemistry. Results CPNE3 was successfully constructed into the eukaryotic expression vector pEGFP-Nl and expressed in 293T and H1299 cells. Furthermore, the location of Copine-3 protein in cytoplasm and nucleus was determined by immunofluorescence staining, immuno Western blotting and immunohistochemistry in those cells and clinical samples. Conclusion The eukaryotic expression vector pEGFP-Nl-CPNE3 is constructed successfully, and Copine-3 protein is localized in cytoplasm and nucleus.

Preventive effect of trace insulin on cognitive dysfunction induced by sevoflurane inhalation anesthesia in newborn rats and its possible mechanism / 解剖学报

Objective To study the preventive effect of microinsulin on cognitive dysfunction induced by sevoflurane inhalation anesthesia in rats and its possible mechanism. Methods Sixty newborn rats were randomly divided into control group (CON), insulin prevention low dose group (LIP), insulin prevention hihg dose group (HIP), and sevoflurane model group (MOD). The prevention group and the model group were induced by sevoflurane to construct rat cognitive dysfunction model. Morris water maze directional sailing test and space exploration test were used to evaluate the learning and memory function of rats; HE staining was used to observe the pathological morphological changes of hippocampus in rats; Flow cytometry was used to detect the hippocampus of rats cell apoptosis; Detection of rapamycin target protein (mTOR) and eukaryotic peptide chain elongation factor 2 (eEF-2) mRNA levels in hippocampus by RT-PCR; The expression levels of brain-derived neurotrophic factor (BDNF), post-synaptic dense protein-95 (PSD-95), synapsin- I, and calmodulin kinase II α (CaMK II α), mTOR and eEF-2 protein were detected by Western blotting. Results The result of the Morris water maze experiment showed that insulin significantly reduced the escape latency and swimming distance of rats, and increased the number of crossing platforms; Flow cytometry result showed that the insulin prevention group significantly inhibited the apoptosis of rat brain neurons, and the inhibition effect of high-dose insulin prevention group was more obvious; RT-PCR and Western blotting analysis found that the expression levels of mTOR and eEF-2 mRNA and proteins in the hippocampus of the model group increased significantly, while the expression levels of BDNF, PSD-95, synapsin- I, and CaMK II α proteins reduced significantly. The expression levels of mTOR and eEF-2 mRNA and proteins in the hippocampus of rats in the insulin prevention group decreased significantly, while the expression levels of BDNF, PSD-95, synapsin- I, and CaMK II α protein increased significantly. The difference was statistically significant (P < 0.05). Conclusion Trace insulin can increase the expression of synapse-related proteins in the hippocampus of cognitive dysfunction rats, reduce their mTOR and eEF-2 mRNA expression levels, and prevent sevoflurane-induced cognitive impairment in rats. The mechanism may be related to the regulation of mTOR-eEF-2 approach.

Expression profiling and functional verification of flavonoid 3'-hydroxylase gene from leaves of Euryale ferox / 中国中药杂志

Leaves of Euryale ferox are rich in anthocyanins. Anthocyanin synthesis is one of the important branches of the flavonoid synthesis pathway, in which flavonoid 3'-hydroxylase(F3'H) can participate in the formation of important intermediate products of anthocyanin synthesis. According to the data of E. ferox transcriptome, F3'H cDNA sequence was cloned in the leaves of E. ferox and named as EfF3'H. The correlation between EfF3'H gene expression and synthesis of flavonoids was analyzed by a series of bioinforma-tics tools and qRT-PCR. Moreover, the biological function of EfF3'H was verified by the heterologous expression in yeast. Our results showed that EfF3'H comprised a 1 566 bp open reading frame which encoded a hydrophilic transmembrane protein composed of 521 amino acid residues. It was predicted to be located in the plasma membrane. Combined with predictive analysis of conserved domains, this protein belongs to the cytochrome P450(CYP450) superfamily. The qRT-PCR results revealed that the expression level of EfF3'H was significantly different among different cultivars and was highly correlated with the content of related flavonoids in the leaves. Eukaryotic expression studies showed that EfF3'H protein had the biological activity of converting kaempferol to quercetin. In this study, EfF3'H cDNA was cloned from the leaves of E. ferox for the first time, and the biological function of the protein was verified. It provi-ded a scientific basis for further utilizing the leaves of E. ferox and laid a foundation for the further analysis of the biosynthesis pathway of flavonoids in medicinal plants.

Gene cloning, protein expression and examination of biological activity of chicken CD40L / 生物工程学报

To obtain chicken CD40L protein, the cDNA was prepared from chicken splenic cells and used as a template to clone and amplify CD40L by PCR. The target gene was cloned into pFastBac vector to construct a pFastBac-chCD40L donor plasmid. Recombinant plasmid was transformed into DH10Bac and recombinant Bacmid-chCD40L was obtained. The Bacmid-chCD40L plasmid was transfected into sf9 insect cells to obtain His-chCD40L protein. In addition, the target gene was cloned into pQM01 vector to construct a pQM01-chCD40L plasmid, recombinant plasmid was transfected into HEK 293T cells to obtain Strep-chCD40L protein. The chCD40L protein was purified by affinity chromatography, and the concentration of purified chCD40L protein was determined to be 0.01 mg/mL. Primary cells were isolated from the bursal tissue of 3-week old SPF chickens, and the chCD40L protein was added to the culture medium to stimulate cells. The chCD40L could bind to CD40 on B cells as examined by Western blotting, indirect immunofluorescence assay and flow cytometry, suggesting that chCD40L protein is biologically active. We successfully obtained chicken CD40L protein of biological activity, which laid the foundation in the in vitro culture of primary B lymphocytes for the isolation and diagnosis of virulent IBDV.

Construction of eukaryotic expression vector and bioinformatics analysis of human kidney and brain protein (KIBRA) / 西安交通大学学报(医学版)

【Objective】 To clone the full-length of human kidney and brain protein (KIBRA) coding sequence in eukaryotic expression vector and provide a model for studying the biological function of KIBRA in breast cancer cells. 【Methods】 Total RNA of human breast cancer cell line MCF7 was extracted. After reverse transcription, the full length of KIBRA (NM_001161661.2) coding region was amplified by PCR, and cloned into eukaryotic expression vector pCMV-Blank. After identification, it was defined officially as pCMV-KIBRA. Then it was transfected into MCF7 cells, and the expression of KIBRA was detected by real-time PCR and Western blotting after 48 hours. The primary, secondary and tertiary structures and post-transcriptional modification sites of KIBRA were analyzed with bioinformatics software. 【Results】 Bacterial PCR, double enzyme digestion and DNA sequencing results showed that the correct sequence of KIBRA was inserted into the vector pCMV-KIBRA. The mRNA and protein expressions of KIBRA were significantly increased in MCF7 cells transfected with pCMV-KIBRA. Bioinformatics analysis showed that KIBRA was composed of 1119 amino acids. There were 52 phosphorylation sites, 1 acetylation site and 5 ubiquitination sites, and the protein structure was mainly α-helix and random coil. 【Conclusion】 The eukaryotic expression vector of full-length of human KIBRA coding sequence was successfully constructed and overexpressed in breast cancer cell line MCF7, which can lay a foundation for studying the biological function of KIBRA in breast cancer.