Effect of diosmetin on ferroptosis of hippocampal cells in rats with bacterial meningitis and the mechanism of SIRT1-Nrf2 signaling pathway / 中华行为医学与脑科学杂志

Objective:To explore the effect and mechanism of diosmetin (Dio) on neuronal ferroptosis in rats with bacterial meningitis (BM).Methods:Male SD rats aged 6-7 weeks of SPF grade were selected for the experiment. The BM model was established by injecting group B hemolytic streptococcus into the cisterna magna of cerebellum. Sixty BM model rats were successfully modeled and divided into model group, low-dose Dio group, medium-dose Dio group, high-dose Dio group and inhibitor group according to the random number table method, with 12 rats in each group. Another 12 weight-matched rats were taken as the control group.The rats in the low-dose Dio group, medium-dose Dio group, high-dose Dio group and the inhibitor group were intragastrically administered with Dio at 50 mg/kg, 100 mg/kg, 200 mg/kg and 200 mg/kg, respectively. The rats in the control group were intragastrically administered with an equal volume of 0.9 % sodium chloride solution. On the day of intragastric administration, the rats in the inhibitor group were intraperitoneally injected with SIRT1 pathway inhibitor EX527 (10 mg/kg), and the rats in the other groups were injected with an equal volume of 0.9% sodium chloride solution. The above interventions were performed once a day for 28 consecutive days. Loeffler neurological score was used to evaluate the neurological impairment in rats. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in cerebrospinal fluid of rats were detected by ELISA. The number of white blood cells in cerebrospinal fluid was detected by a blood cell analyzer. Glutathione (GSH) was detected by micro-enzyme labeling method, malondialdehyde (MDA) was detected by thiobarbituric acid colorimetric method, reactive oxygen species(ROS) was detected by colorimetry, and Fe 2+ level was detected by ferrozine method. Hematoxylin-eosin staining, Prussian blue staining and TUNEL staining were used to observe the pathological damage, iron accumulation and apoptosis in the hippocampus, respectively.Western blot was applied to measure the expression of transferrin (Tf), proliferating cell nuclear antigen (PCNA), Bcl-2-associated X protein (Bax), caspase-3 and SIRT1/Nrf2/HO-1/Gpx4 signaling pathway proteins. Graphpad Prism 9.0 was used for data analysis. One-way ANOVA was used for statistical analysis, and SNK- q test was used for further pairwise comparisons. Results:(1) There was a statistically significant difference in neurological function scores among the 6 groups of rats ( F=125.451, P<0.001). The neurological function score of the model group was lower than that of control group, while the neurological function scores of the low-dose Dio group, medium-dose Dio group, and high-dose Dio group were higher than those of the model group (all P<0.05). The neurological function score of the inhibitor group ((2.57±0.26)) was lower than that of high-dose Dio group ((4.34±0.48)) ( P<0.05). (2) There were statistically significant differences in the levels of IL-6, TNF-α and the number of white blood cells in the cerebrospinal fluid of rats among the 6 groups ( F=127.817, 102.413, 180.967, all P<0.001). The levels of IL-6, TNF-α and the number of white blood cells in model group were higher than those of control group(all P<0.05). The levels of IL-6, TNF-α and the number of white blood cells in low-dose Dio group, medium-dose Dio group and high-dose Dio group were lower than those of model group (all P<0.001), and those in inhibitor group were all higher than those in high-dose Dio group(all P<0.001). (3) There were statistically significant differences in iron deposition rate and neuronal apoptosis rate among the 6 groups of rats ( F=90.857, 88.835, both P<0.001). The iron deposition rate ((18.37±3.14)%) and neuronal apoptosis rate ((27.58±2.63)%) in the inhibitor group were higher than those in the high-dose Dio group ((6.35±1.08)%, (14.02±1.87)%) (both P<0.05). (4) The levels of GSH, ROS, MDA, and Fe 2+ in the hippocampus of the 6 groups of rats showed statistically significant differences ( F=54.465, 106.453, 55.969, 105.457, all P<0.001). The GSH content in the inhibitor group ((103.48±8.76) mmol/g) was lower than that in the high-dose Dio group ((133.97±10.54) mmol/g), while the contents of ROS, MDA, Fe 2+ ((225.17±16.32) μmol/mg, (10.73±1.58) μmol/mg, (62.71±5.43) μg/g) were higher than those of the high-dose Dio group ((131.87±11.67) μmol/mg, (4.35±0.87) μmol/mg, (34.86±2.95) μg/g) (all P<0.05). (5)There were statistically significant differences in the protein levels of Tf, PCNA, Bax, caspase-3, SIRT1, Nrf2, HO-1 and Gpx4 in the hippocampus of the 6 groups of rats ( F=120.179, 107.568, 157.265, 98.031, 90.932, 52.283, 59.424, 114.539, all P<0.001). The protein levels of Tf, Bax and caspase-3 in the hippocampus of inhibitor group were higher than those of the high-dose Dio group, while the protein levels of PCNA, SIRT1, Nrf2, HO-1, Gpx4 were lower than those of the high-dose Dio group (all P<0.05). Conclusion:Diosmetin can activate SIRT1/Nrf2/HO-1/Gpx4 signaling pathway, thereby inhibiting neuronal ferroptosis in BM rats.

Study on inhibitory effects and mechanism of silymarin on glioma in vivo and in vitro / 中国药房

OBJECTIVE To investigate the inhibitory effects of silymarin （SM） on glioma in vivo and in vitro and its potential mechanism. METHODS Human glioma cell line U87 cells were randomly divided into control group， SM low- concentration， SM medium-concentration and SM high-concentration groups （50， 100， 200 μg/mL）， protein kinase B （Akt） activator group （SC79 20 μmol/L）， high-concentration of SM combined with Akt activator group （SM 200 μg/mL+SC79 20 μmol/L）. After drug treatment （except for the control group）， optical density （OD） value， clone formation rate， apoptotic rate， the expressions of proliferation/apoptosis-related proteins [proliferating cell nuclear antigen （PCNA）， B-cell lymphoma-2 （Bcl-2）， Bcl- 2-associated X protein （Bax）， caspase-3]， the phosphorylation levels of Akt/mitogen-activated protein kinase （MAPK） signaling pathway related proteins [Akt， p38 MAPK， extracellular signal-regulated kinase 1/2 （ERK1/2）] were detected in each group. The xenograft tumor model in nude mice was established by injecting U87 cells subcutaneously via the right armpit， and then divided into control group， SM low-dose， SM medium-dose and SM high-dose groups （25， 50， 100 mg/kg）， Akt activator group （SC79 40 mg/kg）， high-dose of SM combined with Akt activator group （SM 100 mg/kg+SC79 40 mg/kg）， with 5 mice in each group. After drug intervention （except for the control group of nude mice）， the tumor mass was weighed and the tumor volume was calculated. RESULTS Compared with control group， the OD values， clone formation rates， protein expressions of PCNA and Bcl- 2， phosphorylation levels of Akt， p38 MAPK and ERK1/2 in SM groups， tumor mass and volume in nude mice of SM groups were all decreased significantly， while the apoptosis rates， protein expressions of Bax and caspase-3 were increased significantly， in a dose-dependent manner （P＜0.05）；the trend of changes in the above indicators in the Akt activator group was opposite （P＜ 0.05）， and Akt activator could significantly attenuate the inhibitory effect of high-concentration/high-dose SM on glioma in vivo and in vitro （P＜0.05）. CONCLUSIONS SM may promote the apoptosis of U87 cells， and inhibit its proliferation， clone formation and tumor growth in xenograft nude mice by inhibiting Akt/MAPK signaling pathway.

Characterization of a family B DNA polymerase from Thermococcus eurythermalis A501 and its application in PCR / 生物工程学报

DNA polymerases are widely used in PCR and play important roles in life science research and related fields. Development of high-performance DNA polymerases is of great commercial interest as the current commercial DNA polymerases could not fully satisfy the requirements of scientific research. In this study, we cloned and expressed a family B DNA polymerase (NCBI accession number TEU_RS04875) from Thermococcus eurythermalis A501, characterized its enzymatic property and evaluated its application in PCR. The recombinant Teu-PolB was expressed in E. coli and purified with affinity chromatography and ion-exchange chromatography. The enzymatic properties of Teu-PolB were characterized using fluorescence-labeled oligonucleotides as substrates. The application potential of Teu-PolB in PCR was evaluated using the phage λ genomic DNA as a template. Teu-PolB has DNA polymerase and 3'→5' exonuclease activities, and is highly thermostable with a half-life of 2 h at 98 ℃. The most suitable PCR buffer is consisted of 50 mmol/L Tris-HCl pH 8.0, 2.5 mmol/L MgCl2, 60 mmol/L KCl, 10 mmol/L (NH4)2SO4, 0.015% Triton X-100 and 0.01% BSA, and the optimal extension temperature is 68 ℃. Under the optimized conditions, a 4 kb target fragment was successfully amplified with an extension rate of 2 kb/min. The yield of the Teu-PolB amplified-DNA was lower than that of Taq DNA polymerase, but its extension rate and fidelity was higher than that of Taq and Pfu DNA polymerases. The biochemical properties of Teu-PolB demonstrate that this enzyme can be used in PCR amplification with high thermostability, good salt tolerance, high extension rate and high fidelity.

Role of PPAR-γ-regulated autophagy in genistein-induced inhibition of hepatic stellate cell activation / 南方医科大学学报

OBJECTIVE@#To investigate the inhibitory effect of genistein on activation of hepatic stellate cells (HSCs) and the role of the autophagy pathway regulated by PPAR-γ in mediating this effect.@*METHODS@#Cultured HSC-T6 cells were exposed to different concentrations of genistein for 48 h, and HSC activation was verified by detecting the expressions of -SMA and 1(I) collagen; autophagy activation in the cells was determined by detecting the expressions of LC3-II and p62 using Western blotting. The autophagy inhibitor 3-MA was used to confirm the role of autophagy in genistein-induced inhibition of HSC activation. A PPAR-γ inhibitor was used to explore the role of PPAR-γ in activating autophagy in the HSCs.@*RESULTS@#Genistein at concentrations of 5 and 50 μmol/L significantly inhibited the expressions of -SMA and 1(I) collagen ( < 0.05), markedly upregulated the expressions of PPAR-γ and the autophagy-related protein LC3-II ( < 0.05) and significantly down-regulated the expression of the ubiqutin-binding protein p62 ( < 0.05) in HSC-T6 cells. The cells pretreated with 3-MA prior to genistein treatment showed significantly increased protein expressions of -SMA and 1(I) collagen compared with the cells treated with genistein only ( < 0.05). Treatment with the PPAR-γ inhibitor obviously lowered the expression of LC3-II and enhanced the expression p62 in genistein-treated HSC-T6 cells, suggesting the activation of the autophagy pathway.@*CONCLUSIONS@#PPAR-γ- regulated autophagy plays an important role in mediating genistein-induced inhibition of HSC activation .

Inhibitory effect of rosuvastatin on migration and invasion of U87 glioma cells in vitro / 中国比较医学杂志

Objective To investigate the inhibitory effect of rosuvastatin on the migration and invasion of U87 glioma cells and its related mechanisms. Methods Cultured U87 cells were treated with 0, 5, 10 and 20 μmol/L rosuvastatin for 24,48 and 72 h. Cell viability was measured by CCK-8 assay. Migration ability of the cells was detected by scratch assay,and invasion ability of the cells was detected by Transwell assay. The expression of matrix metalloproteinase 2(MMP2),MMP9 and the Wnt/β-catenin signaling pathway-related proteins was detected by Western blot assay. Results Compared with the control group,the viability of U87 cells in the 5,10 and 20 μmol/L rosuvastatin groups was decreased (P < 0.01)in a time- and dose-dependent manner. Migration and invasion abilities of the cells were decreased(P <0.01). In addition,the expression levels of MMP2,MMP9,Wnt1,Wnt3a,Wnt7a,and β-catenin were decreased as well (P < 0.01). Conclusions Rosuvastatin can significantly inhibit the migration and invasion abilities of U87 glioma cells, probably related to the blocking of Wnt/β-catenin signaling pathway.

Clinical Observation of Sofren Injection Combined with Vinpocetine Injection in the Treatment of Acute Massive Cerebral Infarction / 中国药房

OBJECTIVE:To investigate clinical efficacy of Sofren injection combined with Vinpocetine injection in the treatment of acute massive cerebral infarction,and its effects on hemorheological indexes and serum NOS.METHODS:A total of 60 patients with acute massive cerebral infarction in our hospital during Jan.2014-Jun.2016 were selected as research objects and divided into trial group and control group according to random number table,with 30 cases in each group.Control group was given Citicoline injection 0.5 g,ivgtt,qd.Trial group was additionally given Vinpocetine injection 20 mg added into 0.9％ Sodium chloride injection 250 mL,ivgtt,qd;1 h later washing tube,they were given Sofren injection 10 mL added into 0.9％ Sodium chloride injection 250 mL,ivgtt,for consecutive 14 d.Clinical efficacies and safety of 2 groups were observed,and hemorheological indexes and NOS levels were observed before and after treatment.RESULTS:The total response rate (83.33％)of trial group was significantly higher than that (50.00％) of control group,with statistical significance (P＜0.05).Before treatment,there was no statistical significance in hemorheological indexes or serum NOS levels between 2 groups (P＞0.05).After treatment,hemorheological indexes of 2 groups were decreased significantly,and the trial group was significantly lower than the control group.The level of serum NOS in 2 groups were increased significantly,and the trial group was significantly higher than the control group,with statistical significance (P＜0.05).No obvious ADR was found in 2 groups.CONCLUSIONS:Sofren injection combined with Vinpocetine injection show significant therapeutic efficacy for acute massive cerebral infarction,can reduce blood viscosity and increase blood perfusion with good safety.