Mechanism of Proliferation and Apoptosis of Acute Promyelocytic Leukemia Cell Line NB4 Induced by TPA / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of phorbol-12-myristate-13-ace-tate (TPA) on the proliferation and apoptosis of acute promyelocytic leukemia cell line NB4 and its molecular mechanism.@*METHODS@#The effect of different concentrations of TPA on the proliferation of NB4 cells at different time points was detected by CCK-8 assay. The morphological changes of NB4 cells were observed by Wright-Giemsa staining. The cell cycle and apoptosis of NB4 cells after TPA treatment were detected by flow cytometry. The mRNA expressions of NB4 cells after TPA treatment were analyzed by high-throughput microarray analysis and real-time quantitative PCR. Western blot was used to detect the protein expression of CDKN1A, CDKN1B, CCND1, MYC, Bax, Bcl-2, c-Caspase 3, c-Caspase 9, PIK3R6, AKT and p-AKT.@*RESULTS@#Compared with the control group, TPA could inhibit the proliferation of NB4 cells, induce the cells to become mature granulocyte-monocyte differentiation, and also induce cell G1 phase arrest and apoptosis. Differentially expressed mRNAs were significantly enriched in PI3K/AKT pathway. TPA treatment could increase the mRNA levels of CCND1, CCNA1, and CDKN1A, while decrease the mRNA level of MYC. It could also up-regulate the protein levels of CDKN1A, CDKN1B, CCND1, Bax, c-Caspase 3, c-Caspase 9, and PIK3R6, while down-regulate MYC, Bcl-2, and p-AKT in NB4 cells.@*CONCLUSION@#TPA induces NB4 cell cycle arrest in G1 phase and promotes its apoptosis by regulating PIK3/AKT signaling pathway.

Integrated Multi-omics Approach Reveals the Interaction of Brain-gut in D-galactose-induced Aging Model Mice / 中国生物化学与分子生物学报

Multiple organs are physiologically and pathologically interconnected during aging, and the brain plays a central role in this process. There is a direct two-way communication between the brain and the gut called “brain-gut interaction”, which is of great significance for the study of aging, and the molecular mechanism remains to be further studied. The aim of this study is to explore the mechanism of aging in the context of brain-gut interaction. The results of general physical signs of mice showed that the amount of exercise decreased, body weight and food intake decreased significantly in aged mice (P < 0. 001, P<0. 05). The thymus index of aged mice was significantly lower than that of normal mice (P< 0. 05), and the thymic pathological results showed that the thymic cortex of aging mice was thinner, the boundary between medulla and cortex was blurred, and the cells were loosely arranged. Metabolomics analysis revealed 317 differential metabolites in feces and 100 differential metabolites in hippocampus. The results of microbiome showed that Bacteroidetes and Firmicutes were the dominant phyla of gut microbiota. Bacteroidetes showed an upward trend and Firmicutes showed a downward trend after aging. KEGG pathway results showed that 26 metabolic pathways were related to the study of aging, among which galactose metabolism, ABC transporter and purine metabolism were of great significance for the brain-gut interaction. The results of Spearman correlation analysis of the three groups showed that the types of metabolites involved were mainly lipids and lipid-like molecules and organic acids and derivatives, and the gut microbiota involved were mainly Bacteroidetes and Firmicutes. In conclusion, the present study demonstrated that the synergistic changes between brain and gut in aging mice were related to the mechanism of aging, which provided new insights into the mechanism of aging process.

Adipose-derived stem cells alleviate the inhibition effect of seawater against epidermal cell proliferation and migration through EGFR/ERK pathway / 第二军医大学学报

Objective: To explore the possible mechanism of human adipose-derived stem cells (hADSCs) promoting seawater immersion wound healing in vitro. Methods: Human epidermal cell line HaCaT cells and artificially simulated seawater were used to establish an in vitro model of cell damage induced by seawater immersion. hADSCs were isolated from human adipose tissues, and a co-culture system of HaCaT cells and hADSCs was established. The proliferation and migration abilities of HaCaT cells were detected by cell counting kit-8 (CCK-8), 5-ethynyl-2′-deoxyuridine (EdU) cell proliferation detection kit and cell scratch test. The activation levels of epidermal growth factor receptor (EGFR)/extracellular-regulated protein kinase (ERK) signaling pathway were detected by Western blotting and real-time quantitative PCR. Results: The proliferation of HaCaT cells cultured with the medium containing 10% artificial seawater was significantly inhibited compared with the cells cultured without artificial seawater (P0.05). The expression of EGFR/ERK signaling pathway in seawater-cultured HaCaT cells was significantly inhibited compared with the cells cultured without seawater and those co-cultured with hADSCs and seawater (P0.05). Conclusion: Seawater can block the activation of EGFR/ERK signaling pathway and inhibit the proliferation and migration of HaCaT cells. hADSCs can promote the activation of EGFR/ERK signaling pathway and reduce the inhibition effect of seawater against proliferation and migration of HaCaT cells.

Intravenous versus articular injection of tranexamic acid for reducing hemorrhage after unilateral total knee arthroplasty / 中国组织工程研究

BACKGROUND: The perioperative hemorrhage of knee surgeries is a difficulty in clinic, and the efficacy of tranexamic acid to reduce postoperative bleeding has attracted more attention, but choosing which administrations remains controversial. OBJECTIVE: To investigate the efficacy of tranexamic acid by intravenous injection or articular injection for reducing the perioperative hemorrhage of total knee arthroplasty. METHODS: Sixty patients undergoing unilateral total knee replacement were enrolled, and were then randomized into three groups (n=20 per group): no tranexamic acid administration (group A); intravenous dropping of 15 mg/kg tranexamic acid before tourniquet application plus 10 mg/kg tranexamic acid at 3 hours postoperatively (group B); articular injection of 50 mL saline diluted with 1 g tranexamic acid through a drainage tube (group C). Two-hour closure of drainage tube was performed in all patients. The postoperative dominant and hidden blood loss, blood transfusion rate, pulmonary embolism as well as lower extremity deep venous thrombosis were recorded. RESULTS AND CONCLUSION: (1) The dominant and hidden blood loss in the groups B and C were significantly less than those in the group A (P < 0.05); the dominant blood loss showed no significant difference between groups B and C (P > 0.05); the group B exhibited a significantly less hidden blood loss compared with group C (P < 0.05). (2) The blood transfusion rate in the groups B and C was significantly lower than that in the group A (P < 0.05). (3) No pulmonary embolism or lower extremity deep venous embolism occurred during 3-month follow-up. (4) That is to say, tranexamic acid can obviously reduce perioperative blood loss and blood transfusion rate without pulmonary embolism or lower extremity deep venous thrombosis, and intravenous administration exerts better clinical effectiveness.

Effects of tannins in Galla Chinensis on pharmacokinetics of rifampicin in vivo and in vitro / 中国中药杂志

This study was aimed to explore the effects of tannins in Galla Chinensis on rifampicin in vivo. In the experiment in vitro, UV spectrophotometry and high performance liquid chromatography (HPLC) were used to investigate the solubility of rifampin in pH 1.3, 6.8, artificial gastric juice environment and artificial intestinal fluid environment as well as the effects of tannins on solubility of rifampin in the above conditions. In the experiment in vivo, the process of rifampicin was studied after intragastric administration of rifampicin and rifampicin+ tannins in Galla Chinensis, and then the pharmacokinetic parameters were calculated. The results showed that rifampicin was constantly precipitated in the artificial gastric juice environment over time, and nearly 85% of the rifampicin was precipitated after 6 hours; it showed a good solubility in the artificial intestinal juice environment. After adding the said tannins, the concentration of rifampicin was decreased significantly in both environments, and the concentration of rifampicin in artificial intestinal juice remained relatively stable, while that in artificial gastric juice remained the original downward trend. The pharmacokinetic parameters displayed that as compared with rifampicin alone, AUC0-t and Cmax were decreased significantly, MRT0-t slowed down significantly, Tmax doubled to 7.0 h and the bioavailability was only 31.65% in rifampicin + tannins in Galla Chinensis group. The experiment indicated rifampicin had a poor solubility in acidic environment and the decrease of bioavailability of rifampicin when in combination with tannin was mainly due to the reduction of rifampicin solubility in intestinal tract by complexation of rifampicin with tannin, thus affecting its absorption in intestinal tract. Therefore, rifampicin and the Chinese herbal medicines or Chinese patent medicines rich in tannin should not be taken simultaneously.

Biochemical characterization of three Aspergillus niger ß-galactosidases

Background: ß-Galactosidases catalyze both hydrolytic and transgalactosylation reactions and therefore have many applications in food, medical, and biotechnological fields. Aspergillus niger has been a main source of ß-galactosidase, but the properties of this enzyme are incompletely studied. Results: Three new ß-galactosidases belonging to glycosyl hydrolase family 35 from A. niger F0215 were cloned, expressed, and biochemically characterized. In addition to the known activity of LacA encoded by lacA, three putative ß-galactosidases, designated as LacB, LacC, and LacE encoded by the genes lacB, lacC, and lacE, respectively, were successfully cloned, sequenced, and expressed and secreted by Pichia pastoris. These three proteins and LacA have N-terminal signal sequences and are therefore predicted to be extracellular enzymes. They have the typical structure of fungal ß-galactosidases with defined hydrolytic and transgalactosylation activities on lactose. However, their activity properties differed. In particular, LacB and lacE displayed maximum hydrolytic activity at pH 4­5 and 50°C, while LacC exhibited maximum activity at pH 3.5 and 60°C. All ß-galactosidases performed transgalactosylation activity optimally in an acidic environment. Conclusions: Three new ß-galactosidases belonging to glycosyl hydrolase family 35 from A. niger F0215 were cloned and biochemically characterized. In addition to the known LacA, A. niger has at least three ß-galactosidase family members with remarkably different biochemical properties.

Identification and Screening of Acid-tolerant LAB from Nomad Yogurt in Gobi Region of Mongolia / 微生物学通报

45 strains of Lactobacillus were isolated from 17 samples of traditional fermented milk in Gobi region of Mongolia. Based on morphological, physiological, biochemistry test and 16S rDNA sequencing analysis, identified as 31 strains of Lactobacillus fermentum(L. fermentum), 12 strains of L. helveticus, one strain of L. plantarum and one strain of L. casei. Survival rate of IMAU20085 is 81.44% in the screening experiment of resistance to the artificial gastric juice (pH 3.0). The isolation and identification of these strains and the screening of high acid-tolerant strains have important meaning to the preservation and exploitation of probiotic resource.