Effect of rapamycin on apoptosis of acute myeloid leukemia THP-1 cells induced by idarubicin / 白血病·淋巴瘤

Objective:To investigate the effect of rapamycin (Rapa) on apoptosis of acute myeloid leukemia THP-1 cells induced by idarubicin (IDA) and its molecular mechanism.Methods:The THP-1 cells were treated with 10, 20, 40 and 80 nmol/L Rapa for 1 h, and the cells without Rapa treatment were set up. Western blot was used to detect the conversion of autophagy marker LC3 protein in THP-1 cells (the ratio of LC3Ⅱ/LC3Ⅰ), flow cytometry was used to detect the apoptotic rate, and the pretreatment concentration of Rapa was determined. THP-1 cells were treated with different concentrations of IDA for 24 h, the cell proliferation inhibition rate of IDA for THP-1 cells was detected by CCK-8 method, and the half maximal inhibitory concentration ( IC50) was calculated. THP-1 cells with or without Rapa treatment were treated by IDA with the concentration of lower than IC50 for 24 h, CCK-8 method was used to detect cell proliferation inhibition rate, flow cytometry was used to detect cell apoptosis, real-time fluorescent quantitative polymerase chain reaction was used to detect the expression changes of autophagy-related genes Beclin-1, LC3 and p62, and Western blot was used to detect the conversion of autophagy marker LC3 protein. Results:The ratio of LC3Ⅱ/LC3Ⅰ in THP-1 cells treated by 20 nmol/L Rapa was higher than that in the untreated cells ( P=0.002 4). The apoptotic rate in THP-1 cells treated by 80 nmol/L Rapa was higher than that in the untreated cells ( P=0.007 3). According to the results of Western blot and flow cytometry, 20 nmol/L Rapa was selected as the pretreatment concentration. The IC50 of IDA for THP-1 cells treated with IDA for 24 h was 59.874 nmol/L. After treated with 50 nmol/L IDA for 24 h, the proliferation inhibitory [(69.67±5.03)% vs. (41.67±3.51)%] and apoptotic rates [(74.35±4.83)% vs. (41.25±5.24)%] in THP-1 cells pretreated by Rapa were higher than those in the unpretreated cells (both P<0.05); the Beclin-1 and LC3 mRNA expression levels and the ratio of LC3Ⅱ/LC3Ⅰ in THP-1 cells pretreated by Rapa were higher than those in the unpretreated cells, and the expression of p62 mRNA was lower than that in the unpretreated cells (all P<0.05). Conclusion:Rapa can enhance the apoptosis of THP-1 cells induced by a relative low dose of IDA, which may be achieved through inducing excessive autophagy in THP-1 cells.

Research progress of miroRNA in the mechanism of cardiac hypertrophy and its role as new drug targets / 国际生物医学工程杂志

Cardiac hypertrophy is a common physiological or pathological process, and pathological cardiac hypertrophy can lead to heart failure, sudden death, etc. The role of microRNA (miRNA or MIR) in myocardial hypertrophy has gradually attracted public attention. miR-1 plays a certain protective role in the occurrence of cardiac hypertrophy. miR-133 is a key factor in the establishment of mast gene program, which is very important for the development of myocardial hypertrophy. Carvedilol and other drugs can regulate the expression of miR-133. miR-208a plays an important physiological role in the cardiovascular system, and its expression level changes dynamically in a variety of cardiovascular diseases such as cardiac hypertrophy, which is closely related to the progression and prognosis of the disease. The expression of miR-199a is up-regulated in pressure-overload cardiac hypertrophy, and it is found that miR-199a can inhibit autophagy of cardiomyocytes and induce the occurrence of cardiac hypertrophy. miR-200c can protect cardiomyocytes through a variety of pathways. miRNA may become an important biomarker or drug therapeutic target for cardiac hypertrophy. With the deepening of the research on non-coding RNAs including miRNA, its regulation on the occurrence of cardiac hypertrophy and the pathological process of heart failure will be further revealed.

Study on mechanical ventilation pressure under continuous cuff pressure monitoring in critical patients / 中华危重病急救医学

Objective:To explore the effective pressure range under continuous cuff pressure monitoring in critical patients with mechanical ventilation, so as to achieve the goal of ensuring ventilation quality and reducing mucosal injury without increasing the incidence of endotracheal catheter displacement and aspiration.Methods:Ninety critically ill patients with non-pulmonary diseases admitted to the department of intensive care unit (ICU) of Airport Hospital of Tianjin Medical University from June 2017 to June 2019 were enrolled, and divided into three groups according to the random number table, with 30 patients in each group. For all patients in the three groups , the head of the bed was raised by 30°and the balloon was measured continuously. Cuff pressure in the three groups were maintained at 20, 25 and 30 cmH 2O (1 cmH 2O = 0.098 kPa) respectively. The patient's air leakage, oxygen saturation, tracheal tube displacement of each group were recorded every hour when the patients were calm. Fiberbronchoscope was used to aspirate sputum during extubation to check for mucosal damage. Chest X-ray examination was used to evaluate pulmonary infection and sputum bacteria culture examination was conducted at the same time. Results:There was no significant difference in gender, age and critical condition among the three groups. The number of patients with airway mucosal injury in the 30 cmH 2O group was significantly higher than that in the 20 cmH 2O group (cases: 8 vs. 4, P < 0.05). There was no significant difference in airway mucosal injury between Group 20 cmH 2O and Group 25, Group 25 cmH 2O and Group 30 cmH 2O. When the balloon pressure was 20, 25, and 30 cmH 2O, there was no significant difference in air bag leakage (cases: 14, 10, 12), trachea catheter displacement (cases: 18, 11, 16), ventilator-associated pneumonia (cases: 3, 4, 3), all P > 0.05, and there was no significant difference in mechanical ventilation time and the hospitalization time [mechanical ventilation time (hours): 77.07±65.34, 80.80±70.20, 77.60±65.23; the length of ICU stay (days): 5.70±3.74, 5.30±4.57, 6.23±3.51, all P > 0.05]. Conclusion:The cuff pressure of 20 cmH 2O will not increase the mechanical ventilation time and hospitalization time of patients, while 20 cmH 2O is much safer in airway mucosal injury.

Construction of EZH2 gene site-directed knock-in Hut78 cells by CRISPR/Cas9 system / 天津医药

Objective To construct the Hut78 cell line with EZH2 gene knocked into by CRISPR/Cas9 system. Methods The EZH2 expression vector pMD-18T-EZH2 with homologous arm and the sgRNA expression vector pSpCas9 (BB)-2A-Puro-sgRNA, which could cut the double stranded genomic DNA, were constructed, and the two vectors were co-transfected into Hut78 cells. Then the expression of EZH2 mRNA was detected by qPCR, and the expressions of EZH2 and H3K27me3 proteins were detected by Western blot assay. Results The pMD-18T-EZH2 and pSpCas9(BB)-2A-Puro-sgRNA recombinant vectors were confirmed by DNA sequencing. When Hut78 cells were transfected with the two recombinant plasmid, qPCR results showed that the expression of EZH2 mRNA was significantly increased, and Western blot analysis showed that the expressions of EZH2 and H3K27me3 proteins were significantly increased. Conclusion EZH2 gene is successfully knocked into Hut78 cells by CRISPR/Cas9 system.

Analysis of the changes of serum throid hormones in post thoracic surgery patients / 国际生物医学工程杂志

Objective To investigate the relationship between thyroid hormone levels and the attack of arrhythmia after thoracic surgery.Methods Information of 44 patients after thoracic surgery form September 2012 to February 2015 in General Hospital of Tianjin Medical University was collected, and divided in to the arrhythmia group and non-arrhythmia group.A retrospective analysis was carried on their ECG, thyroid hormone levels, and physical health, and the parameters were then compared between the two groups.The correlation of triiodothyronine (T3) level and Acute Physiology and Chronic Health Evaluation (APACHE Ⅱ) was analyzed.Results The arrhymia patients' serum T3 and free triiodothyronine (FT3) levels were below normal levels, while the serum T3 and FT3 levels of the non-arrhythmia patients were within normal range, and the differences between the two groups were significant (P＜0.05).No notable change of other thyroid hormones levels and correlation of T3, FT3 and APACHE Ⅱ score were found.Conclusions There is a significant difference between the arrhythmia and non-arrhythmia groups in serum T3 and FT3 levels.Perioperative thyroid hormone replacement therapy is worthy of consideration and trial in the clinical prevention and treatment of arrhythmia and prognostic improvement of patients.

Effect of radiation on collagen type I mRNA expressions in mouse osteoblast in vitro / 国际生物医学工程杂志

Objective Cancer radio-therapy may induce bone damage of the patients.collagen type I gene expressions in osteoblast after radiation indicates the influence of radiation on the function of early and late osteoblast.Methods Bone marrow stromal cells were differentiated into osteoblasts in vitro.and the characteristics was indentified.The collagen type I expressions in early and late stage osteoblasts exposed to 1～4Gy radiation were examined by RT-PCR.Results Compared to control group,collagen type I gene expressions increased in early osteoblast after 1～3 Gy radiation (P＜0.05),while the gene expressions in late osteoblast that cultured 10 days decreased.Collagen type I gene expression in late stage ostoblast after 4 Gy irradiation was greatly higher than that in early stage osteoblast (P＜0.01).Conclusion After 1～3 Gy irradiation,the collagen type I expression in early osteoblast was enhanced,indicating the increased ability of bone formation.The exposure to 1～3 Gy decreased collagen type I expression in late osteoblast and weakened the ability of bone formation.The result of high expression of collagen type I in late osteoblast after 4 Gy irradiation may be the manifestation of compensatory function.