Medical record data-enabled machine learning can enhance prediction of left atrial appendage thrombosis in nonvalvular atrial fibrillation.

BACKGROUND: As a major complication of non-valvular atrial fibrillation (NVAF), left atrial appendage (LAA) thrombosis is associated with cerebral ischemic strokes, as well as high morbidity. Due to insufficient incorporation of risk factors, most current scoring methods are limited to the analysis of relationships between clinical characteristics and LAA thrombosis rather than detecting potential risk. Therefore, this study proposes a clinical data-driven machine learning method to predict LAA thrombosis of NVAF. METHODS: Patients with NVAF from January 2014 to June 2022 were enrolled from Southwest Hospital. We selected 40 variables for analysis, including demographic data, medical history records, laboratory results, and the structure of LAA. Three machine learning algorithms were adopted to construct classifiers for the prediction of LAA thrombosis risk. The most important variables related to LAA thrombosis and their influences were recognized by SHapley Addictive exPlanations method. In addition, we compared our model with CHADS2 and CHADS2-VASc scoring methods. RESULTS: A total of 713 participants were recruited, including 127 patients with LAA thrombosis and 586 patients with no obvious thrombosis. The consensus models based on Random Forest and eXtreme Gradient Boosting LAA thrombosis prediction (RXTP) achieved the best accuracy of 0.865, significantly outperforming CHADS2 score and CHA2DS2-VASc score (0.757 and 0.754, respectively). The SHAP results showed that B-type natriuretic peptide, left atrial appendage width, C-reactive protein, Fibrinogen and estimated glomerular filtration rate are closely related to the risk of LAA thrombosis in nonvalvular atrial fibrillation. CONCLUSIONS: The RXTP-NVAF model is the most effective model with the greatest ROC value and recall rate. The summarized risk factors obtained from SHAP enable the optimization of the treatment strategy, thereby preventing thromboembolism events and the occurrence of cardiogenic ischemic stroke.

The clinical efficacy and adverse effects of Entecavir plus Thymosin alpha-1 combination therapy versus Entecavir Monotherapy in HBV-related cirrhosis: a systematic review and meta-analysis.

BACKGROUND: Previous studies have demonstrated the benefits of thymosin alpha-1 (Tα1) in anti-virus, immunological enhancement and anti-inflammation. However, it is controversial about the efficacy and safety of entecavir (ETV) plus Tα1 combination therapy versus ETV monotherapy in cirrhotic patients with hepatitis B virus (HBV) infection. METHODS: The systematic review and meta-analysis of randomized clinical trials (RCTs) were performed to evaluate the efficacy and safety of ETV plus Tα1 combination therapy versus ETV monotherapy in HBV-related patients with cirrhosis. We performed a systematic literature search via PubMed, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journals Database (VIP), and Chinese Biological Medicine database (CBM). Relative risk (RR) and standardized mean difference (SMD) with a fixed- or random- effect model were calculated. Heterogeneity was assessed through a Cochrane Q-test and I2 values. RESULTS: Seven RCTs involving 1144 subjects were included in the systematic review and meta-analysis. Compared with ETV monotherapy, ETV plus Tα1 combination therapy led to a higher complete response (RR = 1.18; 95% CI, 1.07-1.30). In post treatment for 24 weeks, the HBV DNA undetectable rate and HBeAg loss rate were higher in ETV plus Tα1 group than in ETV alone group (RR = 1.91; 95% CI, 1.56-2.35; RR = 2.05; 95% CI, 1.62-2.60). However, after 48 and 52 weeks of treatment, there was no significant difference between the combination therapy and ETV monotherapy (RR = 1.07; 95% CI, 0.96-1.18; RR = 1.17; 95% CI, 0.89-1.55). At week 52 of treatment, the HBsAg loss rate of ETV plus Tα1 group was no significance with that of ETV alone group (RR = 1.03; 95% CI, 0.15-7.26). In comparison with ETV alone, the some biochemical parameters and liver fibrosis were obviously improved by ETV plus Tα1, and there was significant heterogeneity. In addition, the number of adverse events was significantly reduced by ETV plus Tα1, compared to ETV alone (RR = 0.48; 95% CI, 0.24-0.95). CONCLUSIONS: ETV plus Tα1 might lead to a higher clinical response and a lower comprehensive adverse reaction rate in HBV-related patients with cirrhosis, compared to ETV alone. However, the whole patients included in this meta-analysis were from Chinese mainland, so that more worldwide RCTs with a larger sample size are needed to verify the current findings.

[Oxidative Damage of Bone Marrow Stromal Cells Caused by Chemotherapy Drugs].

OBJECTIVE: To explore the oxidative damage of OP9 cells induced by daunorubicin (DNR) treatment. METHODS: The TMRM probe was used to detect mitochondrial membrane potential by flow cytometry; the reactive oxygen species (ROS) was determined by flow cytometry DCFDA probe; the real-time PCR was used to detect the molecular expression of antioxidant enzyme，glutathione peroxidase (GPX) in OP9 cells; the expression of γ-H2AX was determined by flow cytometry. RESULTS: Compared with normal OP9 cells, the positive rate of TMRM in DNR-treated OP9 cells decreased by 56.7% (P＜0.05); the positive rate of DCFDA in DNR-treated OP9 cells increased by 3.52 times (P＜0.01). Compared with normal OP9 cells, DNR-treated OP9 cells showed a decrease in the expression of GPX4 by 44.22% (P＜0.001); the expression of GPX7 decreased by 65.7% (P＜0.001); the expression of GPX8 decreased by 24.7% (P＜0.001); the positive rate of γ-H2AX in DNR-treated OP9 cells increased (P＜0.05). CONCLUSION: After DNR treatment, mitochondrial membrane potential of OP9 cells decreases; the level of reactive oxygen species increases; the expression of glutathione peroxidase (GPX) molecules decreases significantly; genomic instability increases obviously; the oxidative damage of cells increased.

[Effect of Chemotherapeutic Drug-Induced Damage of Bone Marrow Stroma Cells on Normal Hematopoietic Cells].

OBJECTIVE: To explore the effect of damage of bone marrow stroma cells induced by chemotherapeutic drug on the function of normal hematopoitic cells. METHODS: Senescence cells were detected by flow cytometry after SA-ß-gal staining; real-time PCR was used to detect the expression of a serial molecules in bone marrow stromal cell line OP9 cells; the expression of γ-H2AX was determined by flow cytometry after histone γ-H2AX staining; the colony forming ability of hematopoietic cells was tested by colony formation assay. RESULTS: The percentage of senescence cells in OP9 cells after DNR treatment was 2.24 times as much as that in untreated OP9 cells (P<0.05). Compared with normal OP9 cells, the expression levels of IL-6 and TNF-alpha in DNR-treated OP9 cells increased by 2.73 times (P<0.01) and 0.56 times (P<0.01), and the expression levels of N-cadherin, alpha smooth muscle actin (alpha-SMA), angiopoietin1 (Angpt1) and osteopontin (OPN) decreased by 69.54%（P<0.01），63.90%（P<0.01），87.41%（P<0.01）and 42.78%（P<0.01）respectively. After the co-culture with DNR-treated OP9 cells, the colony formation of normal hematopoietic cells decreased by 47.10% than that co-cultured with untreated OP9 cells (P< 0.05), meanwhile, the percentage of γ-H2AX+ cells in normal hematopoietic cells increased by 2.19 times (P<0.05). CONCLUSION: After treatment with DNR, the senescence cell number of OP9 cells sgnificantly increases; the expression of TNF-α and IL-6 is up-regulated, while the expression of α-SMA, Angpt-1 and OPN is down-regulated as compared with normal OP9 cells. In addition, after co-culture of DNR-treated OP9 cells with normal hematopoietic cells, the colony formation ability of hematopoietic cells decreases and the genome instability of hematopoietic cells increases as compared with normal hematopoietic cells.

[Exploration of Mechanism for Meisoindigo-Inducing K562 Cell Apoptosis by Using Quantitative Proteomic Analysis].

OBJECTIVE: To screen the differentially expressed proteins at the early stage of K562 cells treated with meisoindigo by using tandem mass tags (TMT)-based proteomics technology, and to explore the mechanism for meisoindigo-inducing apoptosis. METHODS: The half inhibitory concentration (IC50) of mesoindigo on K562 cells was determined by CCK8. The flow cytometry was used to assay the apoptosis of K562 cells treated by meisoindigo or DMSO. Total proteins were extracted from the cells treated with 0.2% DMSO (control) or 20 µmol/L meisoindigo (Test) for 2 hours. Then, the TMT-labeling HPLC-MS/MS was used to identify and quantify the peptides and their abundance, all the tests were repeated for 3 times. The Mascot software was used to identify the proteins; the GO annotations, enrichment and cluster analysis were used to analyze the differentially expressed proteins. RESULTS: Meisoindigo-induced K562 cell apoptosis in a dose-dependent manner (r=0.98), 5 544 proteins were identified, 4792 of which were quantified. The protein with expression difference>1.5-folds in Test group accoanted for 8, out of which the expression of 4 proteins were up-regulated and 4 were down-regulated. The differentially expressed proteins mainly associated with reactive oxygen species (ROS). CONCLUSION: Several proteins including DDIT4 were found to have dramatic changes in the early stage of K562 cells treated with meisoindigo by using quantitative proteomics technology. The ROS metabolic process may play important roles in meisoindigo-inducing apoptosis of K562 cells.

Quality of life and self-care in elderly patients with cardiovascular diseases: The effect of a Traditional Chinese Medicine health educational intervention.

AIMS: To explore the effects of a Traditional Chinese Medicine health educational intervention on the quality of life and self-care agency of elderly patients living with chronic cardiovascular disease. BACKGROUND: Cardiovascular disease is a leading cause of morbidity and mortality worldwide. The secondary prevention and treatment for chronic cardiovascular disease emphasize the importance of lifestyle modification. However, behavior-changing is difficult and individual choices are influenced by broader environmental factors. The lifestyle intervention for the purpose of self-care enhancing should be considered the driving force from the cultural element. METHODS: The study was conducted from April 2014 to October 2014. Ninety-eight community dwelling individuals with chronic cardiovascular disease were recruited from Shaoxing and randomized. 48 participants were in the intervention group with a 6-month Traditional Chinese Medicine health education and 50 participants were in the control group with routine care. The main measurements included health-related quality of life and self-care agency, which was assessed by the Short Form-36 Chinese version and the Exercise of Self-Care Agency Scale respectively, and were measured at the baseline and post intervention (6months after baseline). RESULTS: After 6months of intervention, the quality of life and self-care agency in the intervention group were significantly improved. CONCLUSIONS: The traditional Chinese medicine health education is an effective method for promoting quality of life and self-care agency in cardiovascular disease patients. It could be applied as adjunctive care for cardiovascular disease patients self-care supporting.

[Relationship between High Expression of c-FLIP and Drug Resistance of Leukemia Cells].

OBJECTIVE: To explore the effect of c-FLIP expression on drug resistance of Kasumi-1 leukemia cells and its mechanisms. METHODS: Tet-on inducible system was used to construct the conditional expression vector of c-FLIP by cloning the c-FLIP gene into lentivirus vector pLVX-Tight-Puro, then the Kasumi-1 cells were transfected with lentivirus pLVX-Tight-Puro-c-FLIP. The expression of c-FLIP was induced by doxycycline(Dox) for different time and doses, and verified by qRT-PCR and Western blot. On the basis of the overexpression of c-FLIP, the Kasumi-1-c-FLIP cells were treated with CH11 and PB in order to induce apoptosis, and the Giemsa staining was used to show the apoptotic cell morphology. RESULTS: qRT-PCR and Western blot showed the overexpression of c-FLIP, the CH11 and PB can induce Kasumi-1 cell apoptosis, while the c-FLIP overexpression weakened this effects. Western blot showed that the c-FLIP blocked the caspase-8 activation. CONCLUSION: The overexpression of c-FLIP inhibits the apoptosis caused by CH11 and PB, and leads to drug resistance in leukemia cells.

Functional Variant of C-689T in the Peroxisome Proliferator-Activated Receptor-γ2 Promoter is Associated with Coronary Heart Disease in Chinese Nondiabetic Han People.

Objective To investigate the association between the polymorphism of C-689T in the peroxisome proliferator-activated receptor-γ2 (PPARγ2) promoter and coronary heart disease (CHD). Methods This case-controlled study was conducted in nondiabetic Chinese Han people, which enrolled 455 patients with CHD (cases) and 693 subjects without CHD (controls). Data of clinical indexes were collected, including height, body weight, waist circumstance, systolic blood pressure (SBP), diastolic blood pressure (DBP), smoking, drinking, physical activity, as well as body mass index (BMI). Fasting blood glucose (FBG), plasma total cholesterol (TC) and triglyceride (TG) levels were measured. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) was used to determine the PPARγ2 promoter C-689→T substitution. The genotype distribution of PPARγ2 promoter C-689T, allelic frequency, clinical indexes, and laboratorial measurements were compared between the two groups. The effect of genotype on the risk of CHD was assessed using univariate and multivariate regression model. Results The genotype frequencies of CC, CT and TT in PPARγ2 promoter C-689T were 89.7%, 9.9% and 0.4% in the case group, and 93.1%, 6.6% and 0.3% in the control group, respectively (CC vs. CT+TT, χ2= 6.243, P=0.041). Carriers of -689T allele (n=95) had significantly higher TC level than non-carriers (n=1053) (5.12±1.26 vs. 4.76±1.22 mmol/L, P=0.001). Male carriers of -689T allele (n=51) were significantly higher in waist circumference, body weight, TC and TG than male non-carriers (n=656) (all P<0.05). In subjects whose BMI was over 25 kg/m2, carriers of -689T allele (n=82) had significantly higher levels of waist circumference, BMI, SBP and TC than non-carriers (n=231) (all p<0.05). The -689T allele was an independent risk factor for CHD (OR=1.668, 95%CI: 1.031-2.705, P=0.037) after adjusting for age, gender, waist circumference, body weight, BMI, smoking, physical activities, SBP, DBP, FBG, TC and TG level. Conclusion These data support the hypothesis that the -689T allele is associated with an increased risk of CHD, in Chinese Han people and correlates significantly with the profiles of CHD-related risk factors.

[Expression and Asymmetric Division of Numb in Leukemia Cell K562 Line].

OBJECTIVE: To investigate the role of asymmetric division in leukemia cells through detection of expression and asymmetric division of Numb in differentiated and undifferentiated K562 cells. METHODS: Firstly, Hemin was used to induce K562 cell differentiation, and the expression of Numb was detected by the real-time quantitative RT-PCR and flow cytometry. After K562 cells were synchronized by nocodazole, the Numb protein was labeled by immunohistochemical staining, followed by the determination of the terminally differentiated cells through confocal microscopy. The fluorescence intensity was calculated by Image J software, and the cell division pattern was analyzed on the basis of the fluorescence intensities of Numb in 2 divided daughter cells. RESULTS: Compared with the undifferentiated K562 cells, the level of Numb mRNA expression increased 2.3 times (P<0.001). The ratio of Numb positive cells was(67.37±5.01)% in differentiated K562 cells, while that was (43.97±5.72)% in undifferentiated K562 cells (P<0.01). Compared with undifferentiated K562 cells, the ratio of cells with asymmetric division in differentiated K562 cells increased 18.3%, the percentage of cells with symmetry self-renewal reduced 49.7%(P<0.001) and that with symmetry differentiation increased 32%(P<0.001). CONCLUSION: In differentiated K562 cells, expression of Numb and proportion of cells with asymmetric division were higher than that in undifferentiated cells. With the differentiation of leukemia cells, the proportion of cells with asymmetrical division increases, and the proportion of cells with symmetrical self-renewal decreases. The stemness of leukemia cells is maintained mainly through the symmetrical self-renewal.

A novel monoclonal antibody against the N-terminus of Aß1-42 reduces plaques and improves cognition in a mouse model of Alzheimer's disease.

Senile plaques consisting of Amyloid-beta (Aß) peptides, in particular Aß1-42, are the hallmark of Alzheimer's disease (AD) and have been the primary therapeutic targets. Passive immunotherapy with monoclonal antibodies (mAbs) has shown initial success in mouse models of AD. However, the existing Aß-directed mAbs mostly were tested on animal models or patients with advanced disease. The effects and mechanisms of mAbs on animals or human trial participants in the prodromal phase of AD are not fully clarified. In the current study, a novel mAb (3F5) directed against the 1-11 amino acids of Aß1-42 was generated by immunizing mice with an emulsion of full length human Aß1-42. The mAb (3F5) showed the ability to disrupt Aß1-42 aggregation and prevent Aß-mediated neurotoxicity in vitro. In a mouse model of AD, administration with 3F5 for 3 months in 6 months-old mice demonstrated that the mAb specifically bound with Aß1-42 to promote the depolymerization of Aß fibrils, facilitated endocytosis of Aß1-42 by microglia, and attenuated the death and apoptosis of neuronal cells, accompanied by neurite outgrowth. APP/PS1 double-transgenic mice treated with 3F5 mAb showed reduced memory loss, cognitive decline, and decreased levels of amyloid deposits in the brain. Aß1-42 levels in cerebral tissues were also significantly reduced, whereas serum Aß1-42 was markedly increased. Interestingly, the concentration of 3F5 in peripheral circulation is much higher than that in the brain. These results indicate that 3F5 is able to cross the blood-brain barrier (BBB) to bind Aß and initiates the phagocytosis of antibody/Aß complexes by microglia in the amyloid depositing mice. 3F5 also promotes Aß efflux from the brain. As a consequence, the antibody reduces plaques in the AD mouse brain, in association with reduction in the pathology of AD.

[Reconstruction of Humanized Bone Marrow Niche in Immunodeficiency Mouse].

OBJECTIVE: To reconstruct a human bone marrow niche in immunodeficiency mouse (NOD/SCID) so as to provide a model for observing the effect of abnormal BM niche on the occurence and development of leukemia. METHODS: Human platelet lysate(HPL) was obtained by repeated freezing and thawing of concentrated platelet. Bone marrow-derived mesenchymal stem cells were cultured in α-minimal essential medium (α-MEM) containing 10% HPL or 10% FBS. The morphology, cell phenotype, multilineage differentiation potential in vitro and proliferation capacity between the mesenchymal stem cells cultured with HPL or FBS were compared. The human bone marrow formation capacity of HPL-cultured MSC was observed. The MSC was seeded on ß-TCP scaffolds for 12h, then the MSC-coated scaffold were implanted in a subcutaneous pocket on the dorsum of NOD/SCID mice. After 8-12 week, the scaffolds were harvested from the mice, then fixed, paraffin-embedded and stained for HE. RESULTS: Whether cultured in the presence of HPL or FBS, the MSC all displayed a spindle-shaped fibroblast-like morphology; the flow cytometry analysis revealed no obvious differences in cell immunophenotype in this 2 groups; they all have the ability to differentiate towards osteoblasts, adipocytes, and chondrocytes in vitro. However, the mesenchymal stem cells cultivated with HPL-contained medium showed stronger proliferation capacity and higher activity to differentiate towards osteoblasts. Mesenchymal stem cells cultivated with HPL still have in vivo bone-forming capacity. CONCLUSION: HPL cultured MSC have stronger proliferation capacity and potential of differentiate towards osteoblasts, HPL-cultured MSC also can reconstruct humanized bone marrow niche in murine host.

Impact of Abdominal Shape on Short-Term Surgical Outcome of Laparoscopy-Assisted Distal Gastrectomy for Gastric Cancer.

BACKGROUND: Laparoscopy-assisted distal gastrectomy (LADG) has been widely accepted for the treatment for gastric cancer. The aim of the present study was to explore the impact of abdominal shape parameters on gastric antrum cancer patients' short-term surgical outcomes of LADG with D2 lymph node dissection in both genders, including the number of lymph nodes retrieved and surgical safety index. METHODS: This was a retrospective analysis of 177 gastric antrum cancer patients, who underwent LADG between April 2009 and January 2016. The abdominal shape parameters, including abdominal anterior-posterior diameter (APD), transverse diameter (TD), xiphoid process of the sternum-navel distance (XND), and thickness of subcutaneous fat (SCF) at the umbilicus level, were calculated by preoperative abdominal computed tomography (CT) scans. The effects of abdominal shape parameters on the short-term surgical outcomes of LADG were analyzed. RESULTS: In male patients undergoing LADG and D2 lymph node dissection, the number of retrieved lymph nodes was significantly lower in patients with APD ≥17.3 cm (P = 0.005), TD ≥27.4 cm (P = 0.029), SCF ≥1.2 cm (P = 0.014), and BMI ≥22.2 (P = 0.008), whereas in female patients, these were statistically insignificant (P > 0.05). APD, TD, SCF, and BMI were negatively correlated with the number of retrieved lymph nodes in male patients. There was no significant difference in the number of lymph nodes retrieved between high-XND group and low-XND group in either gender. Operation time was significantly shorter in male patients with XND < 17.0 cm (P = 0.044) and in female patients with SCF < 2.15 cm (P = 0.013). Intraoperative blood loss and postoperative complication rate were not significantly different between high- and low-APD groups, high- and low-TD groups, high- and low-XND groups, and high- and low-SCF groups in either gender. Compared with male patients, SCF and TD were significantly higher in female patients. In addition, a higher incidence rate of hypertension was observed in patients of both genders with large APD and SCF, although statistically significant only in male patients. CONCLUSIONS: LADG with D2 lymph node dissection can effectively achieve the lymph node dissection requirement of radical distal gastrectomy for patients with various abdominal shapes. It is worth noting that APD, TD, and SCF can impact on lymph node dissection of LADG in male patients. Nevertheless, in female patients, abdominal shape do not impact on lymph node dissection of LADG. Moreover, LADG with D2 lymph node dissection is proved to be safe for various abdominal shape in both genders, even for abdominal obese patients.

The Cytoprotective Effect of Hyperoside against Oxidative Stress Is Mediated by the Nrf2-ARE Signaling Pathway through GSK-3ß Inactivation.

Glycogen synthase kinase-3ß (GSK-3ß) acts as a negative regulator of NF-E2 related factor 2 (Nrf2) by inducing Nrf2 degradation and nuclear export. Our previous study demonstrated that the flavonoid hyperoside elicits cytoprotection against oxidative stress by activating the Keap1-Nrf2-ARE signaling pathway, thus increasing the expression of antioxidant enzymes, such as heme oxygenase-1 (HO-1), superoxide dismutase (SOD) and catalase. However, the role of GSK-3ß in hyperoside-mediated Nrf2 activation is unclear. Here, we demonstrate that in a normal human hepatocyte cell line, (L02), hyperoside is capable of inducing the phosphorylation of GSK-3ß at Ser9 without affecting the protein levels of GSK-3ß and its phosphorylation at Thr390. Lithium chloride (LiCl) and short interfering RNA (siRNA)-mediated inhibition of GSK-3ß significantly enhanced the ability of hyperoside to protect L02 liver cells from H2O2-induced oxidative damage, leading to increased cell survival shown by the maintenance of cell membrane integrity and elevated levels of glutathione (GSH), one of the endogenous antioxidant biomarkers. Further study showed that LiCl and siRNA-mediated inhibition of GSK-3ß increased hyperoside-induced HO-1 expression, and the effect was dependent upon enhanced Nrf2 nuclear translocation and gene expression. These activities were followed by ARE-mediated transcriptional activation in the presence of hyperoside, which was abolished by the transfection of the cells with Nrf2 siRNA. Furthermore, the siRNA-mediated inhibition of Keap1 also enhanced hyperoside-induced Nrf2 nuclear accumulation and HO-1 expression, which was relatively smaller than the effects obtained from GSK-3ß siRNA administration. Moreover, Keap1 siRNA administration alone had no significant effect on the phosphorylation and protein expression of GSK-3ß. Collectively, our data provide evidence that hyperoside attenuates H2O2 -induced L02 cell damage by activating the Nrf2-ARE signaling pathway through both an increase in GSK-3ß inhibitory phosphorylation at Ser9 and an inhibition of Keap1 and that hyperoside-mediated GSK-3ß inhibition exhibits more significant effects.

[Effect of TBLR1-RARα Fusion Gene on Erythroid Differentiation of K562 Cells].

OBJECTIVE: To explore the effects of TBLR1-RARα on the differentiation induction of leukemia cell line K562 cells into erythroid lineage and to investigate its related mechanisms. METHODS: Tet-Off inducible system was used to construct the conditional expression vector of TBLR1-RARα fusion gene by cloning the TBLR1-RARα fragment into lentivirus vector pLVX-Tight-Puro, the expression of TBLR1-RARα fusion gene was induced by doxycycline (Dox). Then, K562 cells were transfected with lentivirus pLVX-Tight-Puro-TBLR1-RARα-flag, and the expression of fusion proteins was verified by Western blot. After treatment of K562 with all-trans retinoid acid (ATRA), real time RT-PCR was performed to test the expression of erythroid differentiation-related CD71 and α, ε, γ-globins gene. Flow cytometry was used also to analyze the expression of erythroid differentiation markers CD71 and CD235a. Benzidine staining was used to detect the production of hemoglobin in K562 cells. RESULTS: qRT-RCR showed that ATRA could increase the expression level of CD71 and α, ε, γ-globin genes when TBLR1-RARα was expressed. After treatment of ATRA, the proportion of CD71(+) cells detected by the flow cytometry also increased. Benzidine staining showed that ATRA could induce hemoglobin production in K562 cells with TBLR1-RARα fusion gene expression. CONCLUSION: The expression of TBLR1-RARα fusion gene contribute to ATRA-inducing differentiation of K562 cells into erythroid lineage.

[Determination of Th9 cells and IL-9 in children with Mycoplasma pneumoniae infection].

OBJECTIVE: To investigate the clinical significance of T helper type 9 (Th9) cells and interleukin-9 (IL-9) in children suffering from Mycoplasma pneumoniae (MP) infection. METHODS: A total of 86 children who were diagnosed with MP infection between January 2013 and June 2014 were classified into upper respiratory infection (URI) group (n=29), mild MP pneumonia (MPP) group (n=32) and severe MPP group (n=25). Twenty-eight healthy children were used as the control group. Peripheral blood mononuclear cells were isolated by Ficoll density gradient centrifugation, and the percentage of Th9 cells in peripheral blood was measured by flow cytometry. Serum IL-9 level was determined using ELISA. RESULTS: The URI, mild MPP, and severe MPP groups had significantly higher percentages of Th9 cells and IL-9 levels than the control group (P<0.05); the mild MPP and severe MPP groups had significantly higher percentages of Th9 cells and IL-9 levels than the URI group (P<0.05), and the two indices were significantly higher in the severe MPP group than in the mild MPP group (P<0.01). CONCLUSIONS: Children with MP infection have an elevated percentage of Th9 cells and IL-9 expression, both of which are positively correlated with the severity of the disease. It can be predicted that Th9 cells and IL-9 can be used as evaluation indicators for the progression and outcome of children with MP infection.

Inhibition of Forkhead box protein M1 by thiostrepton increases chemosensitivity to doxorubicin in T-cell acute lymphoblastic leukemia.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive type of blood malignancy, deriving from T-cell progenitors in the thymus, and comprises 10-15% of pediatric and 25% of adult primary ALL cases. Despite advances, 20% of pediatric and the majority of adult patients with T-ALL succumb to mortality from resistant or relapsed disease, and the survival rate for patients with resistant or relapsed T-ALL remains poor. Alterations in the expression of Forkhead box protein M1 (FoxM1) have been detected in several types of cancer, and the inhibition of FoxM1 has been investigated as therapeutic strategy in cancer. The present study investigated the effects of the inhibition of FoxM1 by thiostrepton in human T-ALL Jurkat cells. The cells were treated with different concentrations of thiostrepton, either alone or in combination with doxorubicin. Cell viability was measured using CCK-8 assays and the cell cycle distribution, apoptosis and cell-associated mean fluorescence intensity of intracellular doxorubicin were assessed using flow cytometric analysis. The mRNA and protein expression levels were detected by reverse transcription-quantitative polymerase chain reaction and western blot analyses. The inhibition of FoxM1 by thiostrepton significantly decreased the proliferation of the Jurkat cells proliferation in a time- and dose-dependent manner. Cell arrest at the G2/M phase, and apoptosis was significantly increased in the thiostrepton-treated Jurkat cells. Thiostrepton reduced the half maximal inhibitory concentration of doxorubicin in the Jurkat cells, and significantly enhanced the cytotoxicity of doxorubicin within the Jurkat cells by enhancing doxorubicin-induced apoptosis and increasing the accumulation of intracellular doxorubicin. Furthermore, the inhibition of FoxM1 by thiostrepton enhanced doxorubicin-induced apoptosis, possibly through a caspase-3-dependent pathway, and increased the accumulation of intracellular doxorubicin, possibly through downregulating the expression of glutathione S-transferase pi. Collectively, the results of the present study suggested that targeting FoxM1 with thiostrepton resulted in potent antileukemia activity and chemosensitizing effects in human T-ALL Jurkat cells.

[Role of IFN-γ in the regulation of murine hemopoiesis].

This study was aimed to explore the role and mechanism of IFN-γ in the regulation of hemopoiesis in mice. Murine IFN-γ fragment was amplified from murine splenic cells with RT-PCR and plasmid pCDH1-mIFN-γ-EF1-copGFP (pCDH-mIFN-γ-GFP) was constructed. Plasmids pCDH-mIFN-γ-GFP and pCDH1-EF1-copGFP (pCDH-GFP) together with packaging plasmids pPACK-A, pPACK-B and pPACK-C were respectively transfected into 293T cells by using a method of calcium phosphate precipitation to produce lentivirus. Bone marrow mononuclear cells (BMMNC) from male C57BL/6J mice were transfected with the lentiviral vector pCDH expressing mIFN-γ and green fluorescent protein (GFP). The cells were cultured in M3434 semi-solid medium for colony formation assay and transplanted into lethally-irradiated mice through caudal vein injection, and the peripheral blood cell counts and GFP were monitored regularly after transplantation. The results showed that lentiviral vector pCDH-mIFN-γ-GFP was constructed successfully and 293T cells transfected with mIFN-γ secreted mIFN-γ. Transfection of mIFN-γ into BMMNC decreased colony formation, colony number of the mIFN-γ group was significantly less than that of the control group. The recovering of circulating blood cell parameters in mIFN-γ transplantation group was significantly later than control group. GFP positive cells could be detected in the peripheral blood at 8 weeks after transplantation. It is concluded that mIFN-γ may inhibit the colony-forming capacity of transduced BMMNC and delay the hematopoietic reconstitution.

[Dexamethasone and vorinostat cooperatively promote differentiation and apoptosis in Kasumi-1 leukemia cells through ubiquitination and degradation of AML1-ETO].

OBJECTIVE: To probe the effects of dexamethasone (DEX) combined with histone deacetylase (HDAC) inhibitor vorinostat on inhibiting proliferation and inducing differentiation and apoptosis in Kasumi-1 leukemia cells, and its possible mechanisms in order to provide a theoretical basis for the treatment of AML1-ETO positive AML. METHODS: The cell survival, differentiation and apoptosis rates were tested by MTT or flow cytometry analysis after Kasumi-1 cells were treated by DMSO, DEX (20 nmol/L), vorinostat (1 µmol/L) or DEX (20 nmol/L) in combination with vorinostat (1 µmol/L). WB and IP-WB were performed to detect AML1-ETO and its ubiquitination. RESULTS: Treatment with the combination of DEX and vorinostat for 48 h led to statistically significant differences of inhibited proliferation [(42.06±8.20)%], increased differentiation [(52.83±8.97)%] and apoptosis [(52.92±2.53)%] of Kasumi-1 cells when compared with vorinostat [(33.82±9.41)%, (43.93±9.04)% and (42.98±3.01)%, respectively], DEX [(17.30±3.49)%, (22.53±4.51)% and (19.57±2.17)%, respectively] or control [(6.96±0.39)%, (21.73±2.03)% and (6.96±0.39)%, respectively]. Also significant ubiquitination and decreased AML1-ETO protein in Kasumi-1 cells after the combination treatment over single agent or control were observed. CONCLUSION: The results indicated that DEX and vorinostat could synergistically inhibit the Kasumi-1 cells proliferation, induce Kasumi-1 cells differentiation and apoptosis through ubiquitination and degradation of AML1-ETO.

[Effects of transcription factor GATA-2 on transcriptive regulation of iASPP gene].

iASPP can prompt the cell proliferation and inhibit the apoptosis of many cells. There are putative binding sites of transcription factor GATA-2 upstream of iASPP transcription start site. GATA-2 plays an important role in the proliferation and differentiation of hematopoietic stem cells (HSC) and progenitors. This study was aimed to explore the role of GATA-2 protein in iASPP gene transcription. Firstly, the expression of iASPP and GATA-2 protein in some leukemia cell lines was detected by Western blot. Second, The expressive vector of pCMV5-GATA2 and the luciferase reporter vectors containing possible binding sites of GATA-2 were constructed and co-transfected into HEK293 and CV-1 cells. Then the luciferase activity was assayed by luminometer. Also, ChIP assays were performed to further confirm the specific binding of GATA-2 to iASPP promoter. The results showed that GATA-2 was overexpressed in most cell lines with high level of iASPP. GATA-2 exhibited a significant effect on luciferase activity of reporter gene iASPP and in a dose-dependant manner. The relative luciferase activity was up-regulated to about two-fold of the empty vector control when the transfection dose of pCMV5-GATA2 plasmid was increased to 100 ng. While the effect was more significant in CV-1 cells and showed a 6.7-fold increase. The ChIP assay demonstrated the in vivo specific binding of GATA-2 to iASPP. The binding sites of GATA2 were located between nt -361 ∼ -334 in upstream of iASPP gene transcription start site. It is concluded that transcription factor GATA-2 can bind with the cis-regulatory region of the iASPP promoter and up-regulate iASPP expression.