Objective:To measure the concentration of growth differentiation factor-15(GDF-15)in the serum of patients with atrial fibrillation(AF),to study the correlations between the levels of GDF-15 and different factors including basic clinical information,biochemical examinations,and atrial structure,and further to explore the association between GDF-15 and AF types and structural remodeling.Methods:AF patients who were admitted to the ward of the Department of Cardiology at Peking Universi-ty Third Hospital between October 2017 and October 2019 were prospectively enrolled.Patients admitted to the ward at the same time with sinus rhythm and no prior AF history were enrolled in the control group.Clinical information and blood samples of the patients were collected.Enzyme-linked immunosorbent as-say was used to measure the concentration of GDF-15.SPSS 23.0 was used for statistical analysis.Results:In the study,156 AF patients(64 persistent AF and 92 paroxysmal AF)and 38 patients of the control group were included.Serum GDF-15 levels in the AF group were significantly higher than in the control group[1 112(723,1 525)ng/L vs.697(499,825)ng/L,P＜0.001].Serum GDF-15 levels in the persistent AF group were significantly higher than in the paroxysmal AF group[1 140(858,1 708)ng/L vs.1 090(662,1 374)ng/L,P=0.047].The area under the curve(AUC)of serum GDF-15 levels for prediction of AF was 0.736(95％CI:0.651-0.822,P＜0.001).The cut-off value was 843.2 ng/L with a sensitivity of 68.2％and a specificity of 78.9％.The AUC of serum GDF-15 levels for prediction of persistent AF was 0.594(95％CI:0.504-0.684,P=0.047).The cut-off va-lue was 771.5 ng/L with a sensitivity of 82.8％and a specificity of 35.9％.Spearman rank correlation analysis showed that the serum GDF-15 levels were positively correlated with age(r=0.480,P＜0.001),left atrial pressure(LAP,r=0.300,P＜0.001),and also negatively correlated with left atrial appendage flow velocity(LAAV,r=-0.252,P=0.002).Multiple linear regression analysis showed that age and LAP affected the GDF-15 levels significantly(P＜0.05).Logistic regression analysis sug-gested GDF-15(OR=1.002,95％CI:1.001-1.003,P=0.004)and left atrial diameter(LAD,OR=1.400,95％CI:1.214-1.616,P＜0.001)were independent predictors of AF.Conclusion:Serum GDF-15 levels are higher in AF patients.Meanwhile,serum GDF-15 levels are higher in persistent AF patients than paroxysmal AF patients.GDF-15 is associated with AF and atrial structural remodeling.

ObjectiveTo determine whether HBV DNA polymerase is associated with T-cell failure and thus mediates the immune escape of HBV-related hepatocellular carcinoma （HCC） tumor cells， and to investigate the specific molecular mechanisms. MethodsLiver cancer cell lines Huh7 and HepG2 stably transfected with HBV DNA polymerase expression plasmid with Flag （Flag-HBV-P） and intercellular adhesion molecule-1 （ICAM1） were co-cultured with Jurkat cells， and MTT assay， qRT-PCR， and ELISA were used to measure Jurkat cell proliferation， activation （CD69 expression）， and secretion of the cytokine IFN-γ. RNA-seq was used to screen for differentially expressed immune-associated molecules between stably transfected cell lines and control cells， and mRNA half-life and protein half-life assays were used to determine the specific levels of the immune-associated molecules that were affected by HBV DNA polymerase. Related websites were used to predict the transcription factors that may bind to the promoter region of this immune-associated molecule， Western blot was used to verify the effect of transcription factors on the immune-associated molecule， and rescue experiment was used to determine whether HBV DNA polymerase affects the expression level of the immune-associated molecule through this transcription factor. The independent-samples t test was used for comparison between two groups. ResultsThe experimental group had significant reductions in Jurkat cell proliferation， activation， and cytokine secretion compared with the control group （all P<0.01）. Compared with the control group， the experimental group （Huh7 and HepG2 cell lines） had significant reductions in the mRNA and protein expression levels of ICAM1 （all P<0.01）. Website prediction identified the ICAM1 promoter and preliminarily highlighted NFKB1， RELA， and STAT3. Compared with the control group， the experimental group （Huh7 and HepG2 cell lines） had a significant reduction in the protein expression level of p65 （all P<0.01）. After p65 overexpression， there was a significant increase in the protein expression level of ICAM1， and after the expression of p65 was reduced， there was a significant reduction in the protein expression level of ICAM1 （all P<0.01）. In the rescue experiment， there was no significant difference in the protein expression level of ICAM1 between the control group and the experimental group after p65 overexpression （all P>0.05）. After the overexpression of ICAM1， there were no significant differences in the proliferation， activation， and cytokine secretion of Jurkat cells between the control group and the experimental group （Huh7 and HepG2 cell lines） （all P>0.05）. ConclusionHBV DNA polymerase downregulates the level of ICAM1 to mediate HCC immune escape by inhibiting the expression of p65 in NF-κB.

Consecutively hospitalized patients with confirmed coronavirus disease 2019 (COVID-19) in Wuhan, China were retrospectively enrolled from January 2020 to March 2020 to investigate the association between the use of renin-angiotensin system inhibitor (RAS-I) and the outcome of this disease. Associations between the use of RAS-I (angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB)), ACEI, and ARB and in-hospital mortality were analyzed using multivariate Cox proportional hazards regression models in overall and subgroup of hypertension status. A total of 2771 patients with COVID-19 were included, with moderate and severe cases accounting for 45.0% and 36.5%, respectively. A total of 195 (7.0%) patients died. RAS-I (hazard ratio (HR)= 0.499, 95% confidence interval (CI) 0.325-0.767) and ARB (HR = 0.410, 95% CI 0.240-0.700) use was associated with a reduced risk of all-cause mortality among patients with COVID-19. For patients with hypertension, RAS-I and ARB applications were also associated with a reduced risk of mortality with HR of 0.352 (95% CI 0.162-0.764) and 0.279 (95% CI 0.115-0.677), respectively. RAS-I exhibited protective effects on the survival outcome of COVID-19. ARB use was associated with a reduced risk of all-cause mortality among patients with COVID-19.
Angiotensin Receptor Antagonists/therapeutic use* ; Angiotensin-Converting Enzyme Inhibitors/therapeutic use* ; COVID-19 ; Humans ; Hypertension/drug therapy* ; Renin-Angiotensin System ; Retrospective Studies

Objective To assess the difference in left atrial properties between elderly and younger control subjects and the role of left atrium remodeling in patients of different ages with atrial fibrillation.Methods A total of 194 patients with non-valvular atrial fibrillation were enrolled from September 2014 to June 2016.Based on age,patients were divided into an elderly group (≥60 years,n=129) and a younger group (＜60 years,n=65).We evaluated remodeling parameters for the left atrium using an Ultrasound Cardiography (UCG) system in 125 elder subjects,together with 64 control subjects.All remodeling parameters were recorded,including left atrial diameter (LAD),left atrial square (LAS),left atrial pressure (LAP) and left ventricular end-diastolic dimension (LVEDD).Results The elderly group had more female patients and more patients with persistent atrial fibrillation.Meanwhile,scores of CHA2DS2Vsc and levels of N-terminal pro-brain natriuretic peptide (NT-ProBNP) were significantly increased in elderly patients (both P＜0.05).Moreover,the elderly group was associated with increased values of LAD and LAS[(39.1±4.4)mm vs.(37.1±5.3)mm,P＜0.01;and(23.3±4.5)cm2 vs.(21.4±4.8)cm2,P＜0.01;respectively],compared with those in the control group.Spearman's correlation analysis showed that LAD,LAS and LAP were all markedly related to age (r=0.213,P＜0.05;r=-0.175,P＜0.05;r=0.170,P＜0.05;respectively),persistent onset of atrial fibrillation (r=0.401,P＜0.05;r=0.446,P＜0.05;r=0.160,P＜0.05;respectively),and impaired heart function,measured by left ventricular ejection fraction (r=-0.4371,P＜0.05;r=-0.403,P＜0.05;r=-0.364,P＜0.05;respectively) and NT-ProBNP (r=0.485,P＜0.01;r=0.483,P＜ 0.01;r =0.293,P＜ 0.01;respectively).Conclusions Left atrial remodeling properties measured by the UCG system in the elderly with non-valvular atrial fibrillation are more serious than those in mid-aged and young subjects.As a convenient and accurate assessment of remodeling parameters,the UCG system is an excellent option for measuring left atrial remodeling in the elderly population.

Objective To investigate the effects of a novel scientific research practice model on medical undergraduates'!cognition and behavior. Method Totally, 60 medical undergraduates took part in the research. All of them accepted scientific research training by using improved tutorial system + team-based learning (TBL) combat training models. Before and after training, students completed the same ques-tionnaires respectively. The content included the purpose of participating in scientific research activities, the interest of scientific research, and the confidence and satisfaction of publishing scientific research papers, etc.. SPSS 16.0 was used to conduct non parametric Mann-Whitney test or Wilcoxon non parametric test to the pre and post survey data. Results Fifty-seven students (95.0%) were satisfied with the novel teaching model. Before and after training, the liking scores for scientific research practice rose from 1.12 (95%CI=0.65 to 1.59) to 5.87 (95%CI=5.34 to 6.39), P=0.001. Fifty-three students (88.3%) proactively participated in research work after training compared with 21 students (35.0%) before training, P=0.000. More students had confidence in publishing academic papers on Chinese core journals or Science Citation Index journals after training (P=0.000, P=0.003 respectively). 57 students (95%) said they were very satisfied or satisfied with the training of scientific research and practice. Conclusion Improved tutorial system+TBL research combat training model can stimulate students'!interest in scientific research and make them have more pos-itive cognition and behavior on scientific research work.

Objective To observe the effect of CIP4(Cdc42 interacting protein 4)on human renal tubular epithelial to mesenchymal transition(EMT)induced by transforming growth factor β1(TGF-β1)and to study the associated mechanism. Methods Human proximal tubular epithelial cells (HK-2 cell line) were cultured with TGF-β1 (10μg/L) for 72 hours. The protein expressions of E-cadherin and α-SMA were measured by Western blotting. One set of siRNA oligos specific for CIP4 and CIP4 construction of the entire coding sequence were designed based on the full CIP4 sequence in GenBank. Then HK-2 cells were transfected with CIP4-siRNA or pcDNA3.1-hCIP4 via lipofactamine 2000. The protein expressions of CIP4, E-cadherin and α-SMA were evaluated respectively in control cells, TGF-β1 treated cells, siRNA transfected cells, pcDNA3.1-hCIP4-transfected cells by Western blotting. The distribution of E-cadherin and α-SMA was observed by confocal microscope. After TGF-β1-treated HK-2 cells were interferenced with specific inhibitor of PI3K-Akt (wortmannin) 1μmol/L for 48 hours, Western blotting was used to detect the CIP4 protein in control cells and interferenced cells. Results With TGF-β1 stimulation, the expression of E-cadherin protein was decreased markedly (P＜0.05), and in contract, the expression of α-SMA were increased notably (P＜0.05), which revealed that TGF-β1 could induce EMT. After transfected with CIP4-siRNA, the protein expression of E-cadherin was increased (P＜0.05), and the protein expression of α-SMA was decreased (P＜0.05). The EMT induced by TGF-β1 was effectively reversed. After transfected with pcDNA3.1-hCIP4, the expression of E-cadherin protein was down-regnlated (P＜0.05), and the expression of α-SMA protein was up-regulated compared with control group (P＜0.05), leading to EMT. After HK-2 cells were interferenced with wortmannin for 48 hours, the expression of CIP4 was decreased (P＜0.05). Conclusion TGF-β1 upregulates the expression of CIP4 via PI3K-Akt pathway, and CIP4 may participate in EMT induced by TGF-β1.

Recently, phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is suggested as a new agent in the fighting against fibrogenesis. In tumor, DJ-1 is identified as a negative regulator of PTEN. But the expression of DJ-1 and the regulation of PTEN in fibrosis are unclear. Renal fibrosis was induced in 5/6 subtotal nephrectomy rat model. Human proximal tubular epithelial cells (HKC) were treated with transforming growth factor-beta 1 (TGF-β1), or transfected with DJ-1 or PTEN. Confocal microscope was used to investigate the localization of DJ-1 and PTEN. The selective phosphoinositide-3 kinase (PI3K) inhibitor, LY294002, was administered to inhibit PI3K pathway. The DJ-1 and PTEN expression, markers of epithelial-mesenchymal transition (EMT) and Akt phosphorylation were measured by RT-PCR, Western blotting or immunocytochemistry. In vitro, after HKC cells were stimulated with 10 ng/mL TGF-β1 for 72 h, the expression of DJ-1 was increased, and that of PTEN was decreased. In vivo, the same results were identified in 5/6-nephrectomized rats. In normal HKC cells, most of DJ-1 protein localized in cytoplasm, and little in nucleus. TGF-β1 upregulated DJ-1 expression in both cytoplasma and nuclei. In contrary, TGF-β1 emptied cytoplasmic PTEN protein into nucleus. Overexpression of DJ-1 decreased the expression of PTEN, promoted the activation of Akt and the expression of vimentin, and also led to the loss of cytoplasmic PTEN. Contrarily, overexpression of PTEN protected HKC cells from TGF-β1-induced EMT. In conclusion, DJ-1 is upregulated in renal fibrosis and DJ-1 mediates EMT by suppressing cytoplasmic PTEN expression and Akt activation.

Recently,phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is suggested as a new agent in the fighting against fibrogenesis.In tumor,DJ-1 is identified as a negative regulator of PTEN.But the expression of DJ-1 and the regulation of PTEN in fibrosis are unclear.Renal fibrosis was induced in 5/6 subtotal nephrectomy rat model.Human proximal tubular epithelial cells (HKC) were treated with transforming growth factor-beta 1 (TGF-β1),or transfected with DJ-1 or PTEN.Confocal microscope was used to investigate the localization of DJ-1 and PTEN.The selective phosphoinositide-3 kinase (PI3K) inhibitor,LY294002,was administered to inhibit PI3K pathway.The DJ-1 and PTEN expression,markers of epithelial-mesenchymal transition (EMT) and Akt phosphorylation were measured by RT-PCR,Western blotting or immunocytochemistry.In vitro,after HKC cells were stimulated with 10 ng/mL TGF-β1 for 72 h,the expression of DJ-1 was increased,and that of PTEN was decreased.In vivo,the same results were identified in 5/6-nephrectomized rats.In normal HKC cells,most of DJ-1 protein localized in cytoplasm,and little in nucleus.TGF-β1 upregulated DJ-1 expression in both cytoplasma and nuclei.In contrary,TGF-β1 emptied cytoplasmic PTEN protein into nucleus.Overexpression of D J-1 decreased the expression of PTEN,promoted the activation of Akt and the expression of vimentin,and also led to the loss of cytoplasmic PTEN.Contrarily,overexpression of PTEN protected HKC cells from TGF-β1-induced EMT.In conclusion,DJ-1 is upregulated in renal fibrosis and DJ-1 mediates EMT by suppressing cytoplasmic PTEN expression and Akt activation.

Objective To observe the expression and localization of CIP4 (Cdc42 interacting protein-4) in the renal fibrosis and the effect of CIP4 on the expression of E-cadherin,vimentin and β-catenin tyrosine phosphorylation. Methods In vitro, the human tubular epithelial cells (HK-2 cell line) were cultured with 10 μg / L TGF-β1 for 72 h. The protein expressions of CIP4, E-cadherin, vimentin and β-catenin tyrosine phosphorylation were measured by Western blotting; the expression of CIP4 mRNA was detected by RT-PCR. The intracellular distribution of CIP4 was observe by confocal microscope. In vivo, Masson staining was used to evaluate the level of renal fibrosis; the expression and distribution of CIP4 in renal tissue were detected by immunohistochemistry. HK-2 cells were transfected with pcDNA3. 1-CIP via lipofectamine 2000. The expressions of E-cadherin, vimentin and β-catenin tyrosine phosphorylation level in the transfected cells were detected by Western blotting. Results The expressions of CIP4 mRNA and protein were up-regulated in renal tubular EMT cells. Most of CIP4 protein localized in cell membrane, and some was in cytoplasm. After stimulation by TGF-β1, the expression of CIP4 protein both in cytoplasm and nucleus was greatly increased (P ＜0.05),especially in cytoplasm. In vivo, CIP4 was expressed in renal tubular epithelia, but little expressed in glomeruli. In renal from 5/6 nephrectomized rats, CIP4 expression was significantly increased. In the CIP4 transfectants, the expression of CIP4, vimentin and β-catenin tyrosine phosphorylation level were up-regulated (P ＜0.05), but E-cadherin expression was suppressed (P ＜0.05).Conclusion The overexpression of CIP4 is likely to take part in the epithelial-to-mesenchymal transition process, thereby promoting the renal fibrosis.

Objective To investigate the inhibitory effects of overexpression of PTEN on renal epithelial-mesenchymal trans-differentiation induced by TGF-β1,and the signaling transduction mechanism.Methods HKC cells were transfected with GFP-PTEN via lipofectAMINE2000.The efficiency of transfection was detected by fluorescence microscope.The expression of PTEN protein and mRNA in the translected cells was detected by Western blot and RT-PCR respectively.The experiment was divided into four groups:normal group,TGF-β1 stimulation group,GFP-PTEN+TGF-β1 group and empty vector+TGF-β1 group.The expression of E-cadherin,a-SMA,Akt and p-Akt was detected by Western blot.Results Most ceils transfected with GFP-PTEN expressed GFP.The expression of PTEN protein and mRNA was strongly increased when HKC cells were transfected with GFP-PTEN(all P<0.05).In both TGF-β1 stimulation group and empty vector+TGF-β1 group,the expression level of E-cadherin was lower(all P<0.05),while that of p-Akt and a-SMA was higher than in normal group(both P<0.05).The expression level of p-Akt and a-SMA in GFP-PTEN+TGF-β1 group was Iower(both P<0.05),while that of E-cadherin was higher than in TGF-β1 stimulation group and empty vector+TGF-β1 group(both P<0.05).The expression of Akt was similar in the four groups.Conclusion Overexpression of PTEN can inhibit renal epithelial-mesenehymal trans-differentiation induced by TGF-β1 through suppressing the activation of PI3K/Akt signal pathway.