AIM: To investigate whether glucosylceramide synthase (GCS) regulates apoptosis-related gene bcl-2 expression via MEK/ERK signaling pathway , thus enhancing drug resistance of K 562/A02 human leukemia multidrug resistant cell line.METHODS:siRNA targeting GCS was transfected into K562/A02 cells.Bcl-2, p-ERK and total ERK expression at mRNA and protein levels after GCS knockdown were detected by real-time PCR and Western blotting .After exposed to MEK-ERK pathway inhibitor U0126, the expression of Bcl-2 at mRNA and protein levels also was analyzed by real-time PCR and Western blotting , respectively.The viability of the cells was evaluated by CCK-8 assay.RESULTS:The expression of GCS and Bcl-2, as well as MEK/ERK signaling were significantly inhibited in K 562/A02 cells by GCS siRNA transfection compared with negative control group .Inactivation of MEK/ERK signaling due to U0126 treatment de-creased Bcl-2 mRNA and protein levels in a concentration-dependent manner , and sensitized K562/A02 cells to adriamy-cin.CONCLUSION:GCS may affect the expression of apoptosis-related gene bcl-2 by MEK/ERK signaling pathway , thus regulating multidrug resistance of human leukemia K 562/A02 cells.

OBJECTIVETo investigate whether transcription factor-kappaB (NF-κ B) is involved in the modulation of P-glycoprotein (P-gp) by glucosylceramide synthase (GCS) in a multidrug resistance leukemia cell line K562/A02 and to explore the relationship between NF-κ B and extracelluar signal-regulated kinase (ERK).

METHODSK562/A02 cells were treated with GCSsiRNA, pyrrolidine dithiocarbamate (PDTC, a NF-κ B specific inhibitor) and U0126 (a MEK1/2 inhibitor), respectively. The expression of GCS and multidrug resistance protein 1 (MDR1) mRNA were analyzed with qRT-PCR. Various proteins of different groups were measured by Western blotting.

RESULTSAfter transfected with GCSsiRNA for 48 h, GCS mRNA were reduced by 62% (51%-73%) and MDR1 mRNA was reduced by 52% (43%-61%) in the K562/A02 cells. Compared with the negative control, relative expression of NF-κ B p65 in nuclear and P-ERK1/2 were both down-regulated, and P-gp was also inhibited significantly at 72 h after transfected with GCSsiRNA (P< 0.05). In addition, the expression of P-gp was decreased at 24 h with 80 μ mol/L PDTC and 48 h with 20 μ mol/L PDTC. P-ERK1/2 was inhibited significantly when the cells were treated with 20 μ mol/L U0126 for 48 h. The expression of NF-κ B p65 in nuclear and P-gp were also down-regulated.

CONCLUSIONNF-κ B can modulate the effect of GCS on P-gp in K562/A02 cells. P-ERK1/2 can activate NF-κ B in above signal transduction pathway.

ATP-Binding Cassette, Sub-Family B, Member 1 ; genetics ; metabolism ; Cell Line, Tumor ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Glucosyltransferases ; genetics ; metabolism ; Humans ; K562 Cells ; Leukemia ; genetics ; NF-kappa B ; genetics ; metabolism

Objective:To analyze the clinical characteristics and causes of death of 80 dead cases with confirmed coronavirus disease 2019 (COVID-19).Methods:The clinical data of 80 dead patients with COVID-19 who were admitted to Renmin Hospital of Wuhan University from January 11 to February 11, 2020 were retrospectively analyzed.The laboratory examination indexes (including white blood cells, lymphocytes, procalcitonin (PCT), lactic acid, D-dimmer, fibrinogen degradation products, N-terminal pro-brain natriuretic peptide (N-proBNP), ultra sensitive-troponin I, lactate dehydrogenase (LDH) and CD4 + T lymphocyte) of the patients at the time of admission were compared with the indexes at the last time before death. Statistical analysis was conducted by using paired t test or Wilcoxon′s signed rank test. Results:The median age was 72 years old of the 80 patients, and 78.75%(63/80) of them were older than 60 years. Thirty-six cases (45.00%) were severe and 44(55.00%) were critical at admission. Fifty-eight cases (72.50%) had underlying diseases. The common underlying diseases were hypertension, diabetes mellitus, coronary atherosclerotic heart disease, and chronic obstructive pulmonary disease. Comparing the patients′ first laboratory tests at admission with those before death, white blood cells increased (8.01(4.86, 12.29)×10 9/L vs 12.55(8.25, 17.66)×10 9/L), lymphocytes decreased (0.70(0.46, 0.88)×10 9/L vs 0.54(0.39, 0.75)×10 9/L), PCT increased (0.20(0.11, 0.74) μg/L vs 1.00(0.20, 1.99) μg/L), lactic acid increased (2.10(1.40, 3.10) mmol/L vs 3.10(2.60, 4.10) mmol/L), D-dimmer increased (4.33(0.97, 18.98) mg/L vs 15.29(5.17, 53.44) mg/L), fibrinogen degradation products increased (15.90(3.58, 76.60) mg/L vs 63.14(21.23, 110.67) mg/L), N-proBNP increased (1 078.00(347.35, 2 996.50) ng/L vs 3 439.50(1 576.00, 9 281.50) ng/L), ultra-sensitive troponin I increased (0.08(0.03, 0.17) μg/L vs 0.33(0.14, 2.47) μg/L), LDH increased (397.00(327.00, 523.50) U/L vs 624.00(481.00, 854.00) U/L) and CD4 + T lymphocyte decreased (137.00(104.00, 168.00)/μL vs 97.00(67.00, 128.00)/μL). The differences between the two groups were all statistically significant ( W=238.00, 1 053.50, 150.00, 152.00, 192.00, 190.00, 108.00, 57.00, 53.00 and 40.00, respectively, all P<0.05). All patients received antiviral and respiratory-support therapy and the main cause of death was respiratory failure caused by intractable hypoxemia and multiple organ failure. Among them, seven cases died in one day hospitalization, and 66 cases died in seven days hospitalization. Conclusions:Elderly patients with a variety of chronic underlying diseases have poor prognosis. It′s essential to pay more attention and deal with the above clinical characteristics at an early stage to improve the outcome of the COVID-19 patients.

Objective:To investigate the associations of brain white matter integrity deficits, and to explore the association of fractional anisotropy (FA) abnormality with clinical symptoms and cognitive impairments, as well as the prediction effect of the FA alterations on symptoms and cognitive function outcomes in the acute stage of schizophrenia from the whole brain level based on magnetic resonance diffusion tensor imaging (DTI).Methods:From November 2019 to December 2020, thirty-eight patients with first-episode schizophrenia and 38 healthy controls were recruited in this study. Wisconsin card classification test (WCST), digit span test (DST forward/backward), verbal fluency test, Stroop (A/B/C), trail making test (TMT-A/B), as well as positive and negative syndrome scale (PANSS) were utilized to evaluate patients' cognitive function and clinical symptoms both before and after 8 weeks of risperidone monotherapy. T1-weighted images and DTI data of all the subjects were collected . FSL and SPM8 were used to preprocess MRI data and compare the between-group differences of FA. Support vector machine (SVM) analysis was used to evaluate the accuracy of abnormal FA values in differentiating schizophrenic patients from healthy controls. Finally, stepwise multiple regression analysis or generalized linear models were used to explore the associations between white matter integrity and symptoms or cognition.Results:Before treatment, patients' FA values of right medial temporal lobe (mTL), cuneus, anterior cingulate gyrus (ACG) and inferior parietal lobe (IPL) were significantly lower than those in healthy controls ( P<0.01, GRF corrected), and patients' FA values of bilateral middle cingulate gyrus (mCG) were significantly higher than those in the control group ( P<0.01, GRF corrected). SVM analysis showed that four combinations could distinguish the patients from the control with the most accurate rate of 89.47%. Patients' baseline decreased FA values in the right IPL were positively associated with their increased total response time in WCST ( β=0.489, P=0.003, FDR corrected), correct response time in WCST ( β=0.450, P=0.008, FDR corrected), error response time in WCST ( β=0.435, P=0.008, FDR corrected), TMT-B ( β=0.296, P=0.042, FDR corrected), Stroop-C ( β=0.345, P=0.035, FDR corrected), and PANSS-P ( β=0.321, P=0.042, FDR corrected). Reduced FA values in the right mTL in patient group were significantly negatively related to the total time spent on the TMT-A ( β=-0.425, P=0.009, FDR corrected) and TMT-B ( β=-0.325, P=0.026 with FDR correction). Increased FA values in right mCG in patient group demonstrated positive associations with total response time in the WCST ( β=0.585, P=0.002, FDR corrected), correct response time in WCST ( β=0.524, P=0.003, FDR corrected), error response time in WCST ( β=0.536, P=0.003, FDR corrected) and total time consuming in TMT-B ( β=0.484, P=0.004, FDR corrected), as well as negative associations with DST-forward ( β=-0.319, P=0.042, FDR corrected). After treatment, patients' percentage changes in total response time of WCST ( β=0.715, P<0.001, FDR corrected), correct response time of WCST ( β=0.752, P<0.001, FDR corrected), as well as total time-consuming of TMT-A ( β=1.333, P=0.001, FDR corrected) showed positive correlations with baseline increased FA values in the left mCG. Percentage alteration of Stroop-B was negatively correlated with baseline FA values in the right cuneus ( β=-0.745, P=0.015, FDR corrected). Conclusions:The combination of abnormal FA values in multiple brain regions may be potential biomarkers to distinguish schizophrenic patients from healthy volunteers. There was regional dependence in the associations of the impairment of white matter integrity with the cognitive impairment, the severity of psychopathological symptoms as well as the prognosis of patients in the acute stage.

Objective:To analyze the risk factors of fatal outcome in patients with severe COVID-19.Methods:The clinical characteristics of 107 patients with severe COVID-19 admitted in Renmin Hospital of Wuhan University from February 12 to March 12, 2020 were retrospectively analyzed. During the hospitalization 49 patients died (fatal group) and 58 patients survived (survival group). The clinical characteristics, baseline laboratory findings were analyzed using R and Python statistical software. The risk factors of fatal outcome in patients with severe COVID-19 were analyzed with multivariate logistic regression.Results:Univariate analysis showed that the two groups had statistically significant differences in age, clinical classification, dry cough, dyspnea and laboratory test indicators ( P<0.05 or <0.01). The random forest model was used to rank the significance of the statistically significant variables in the univariate analysis, and the selected variables were included in the binary logistic regression model. After stepwise regression analysis, the patient’s clinical type, age, neutrophil count, and the proportion of CD3 cells are independent risk factors for death in severe COVID-19 patients. Dry cough is an independent protective factor for the death of severe COVID-19 patients. Conclusion:COVID-19 patients with fatal outcome are more likely to have suppressed immune function, secondary infection and inflammatory factor storm. These factors may work together in severe patients, leading to intractable hypoxemia and multiple organ dysfunction and resulting in fatal outcome of patients. The study indicates that timely intervention and treatment measures against above factors may be effective to save the lives of patients with severe COVID-19.