BACKGROUND:Chitosan biological materials can induce bone marrow mesenchymal stem cells to differentiate toward neurons. As a derivative of chitosan, carboxymethyl chitosan has a series of excelent properties. However, whether carboxymethyl chitosan can induce the neuronal differentiation of bone marrow mesenchymal stem cells remains unclear.OBJECTIVE:To investigate the effect of carboxymethyl chitosan thermosensitive hydrogel on the differentiation of bone marrow mesenchymal stem cells into neurons and the possible mechanism.METHODS:Passage 3 bone marrow mesenchymal stem cells from rats were selected and cultured in carboxymethyl chitosan thermosensitive hydrogel extracts in different concentrations (0, 50, 100, 150, 200, 500 g/L). Control cells were cultured in culture medium with no addition of carboxymethyl chitosan thermosensitive hydrogel extracts. MTT assay was performed to investigate the effects of different concentrations of carboxymethyl chitosan thermosensitive hydrogel extracts on bone marrow mesenchymal stem cell proliferation. Western blot assay was used to explore the effect of 150 g/L carboxymethyl chitosan thermosensitive hydrogel extracts on the expression of neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, β3-tubulin, Notch1 and Jag1 protein.RESULTS AND CONCLUSION:MTT assay showed that carboxymethyl chitosan thermosensitive hydrogel promoted the cell proliferation, and the proliferation rate reached the peak at the concentration of 150 g/L. Western blot assay showed that the cells induced by 150 g/L carboxymethyl chitosan thermosensitive hydrogel extract had significant increases in neuron-specific enolase, Nestin, Vimentin, NF-M, microtubule associated protein 2, glial fibrillary acidic protein, and β3-tubulin protein expression, and obvious decreases in Notch1 and Jag1 protein expression in comparison with the control group. These results indicate that the carboxymethyl chitosan thermosensitive hydrogel induces rat bone marrow mesenchymal stem cells to differentiate toward neurons, and suppresses the activity of Notch signal pathway in the process of differentiation.

Background and purpose:Δ133p53 can promote tumor cell growth, but the exact mechanism is not clear. This study was aimed to observe the expression and signiifcant of the p53 isoformsΔ133p53 and p53 gene downstream molecules MDM2 and cyclin G1 genes by 5-FU-MKN45 gastric cancer cell line model. Methods:Af-ter using different concentrations of 5-FU (50μg/mL, 100μg/mL) to human gastric cancer cell line MKN45, inhibition rate should be detected by MTT assay, the changes ofΔ133p53 mRNA, MDM2 mRNA and cyclin G1 mRNA express-ing were detected by reverse transcription-polymerase chain reaction (RT-PCR). Differences between these groups were analyzed by ANOVA, comparisons within groups were analyzed by t-test, bivariate correlation was analyzed by Pearson linear correlation. Results:MTT results showed that with the increased concentration of 5-FU and the extension of time, the cell inhibition rates increased gradually. The inhibition rates of 50μg/mL 5-FU were 41.10%, 54.79%and 68.48%, for culturing 24, 48 and 72 hours. There were statistically signiifcant differences between the groups(F=45.52, P=0.00). The inhibition rates of 100μg/mL 5-FU were 69.53%, 78.21%and 86.92%, for culturing 24, 48 and 72 hours. There were statistically signiifcant differences between the groups(F=85.58,P=0.00). The inhibition rates of 50 and 100μg/mL were 41.10%and 69.53%, for culturing 24 hours. There were statistically signiifcant differences between the groups(F=51.29, P=0.00). The inhibition rates of 50 and 100μg/mL were 54.79%and 78.21%, for culturing 48 hours. There were statistically signiifcant differences between the groups(F=51.29, P=0.00). The inhibition rates of 50 and 100μg/mL were 68.48%and 86.82%, for culturing 72 hours. There were statistically signiifcant differences between the groups(104.91, P=0.00). RT-PCR results showed that with the increase of the concentration of 5-FU, theΔ133p53 mRNA, MDM2 mRNA and cyclin G1 mRNA expression gradually declined in gastric cancer cell line MKN45 cells, and there were statistically signiifcant differences between the groups(F=738.532, 1 396.607, 2 785.56,P=0.00). Cor-relation analysis showed that the expressions ofΔ133p53 mRNA and MDM2 mRNA in gastric cancer were positively correlated (r=0.871, P=0.01), while the expression of cyclin G1 mRNA and p53 mRNA had no obvious relevance (P=0.13). Conclusion:In the 5-FU-MKN45 gastric cancer cell line model, anti-tumor pathway ofΔ133p53 isomers is related with MDM2 but was not related with cyclin G1.

Objective:To investigate the role and mechanism of long non-coding RNA (lncRNA) gastric cancer associated transcript 3 (GACAT3) in glioma radioresistance.Methods:Real-time reverse transcription PCR (RT-qPCR) was used to detect the expression of lncRNA GACAT3 and miR-497 in human astrocyte NHA cells and glioma cells U251. NC-siRNA and GACAT3-siRNA were transfected into U251 cells, and the cells were treated with X-ray irradiation. Colony formation assay was used to detect the survival fraction of U251 cells. The apoptosis of U251 cells was detected by flow cytometry. Western blot was used to detect the expression of cysteine containing aspartate specific protease 3 (Caspase-3) in U251 cells. Bioinformatics software and dual luciferase reporter gene assay were used to predict and verify the targeting relationship between lncRNA GACAT3 and miR-497, and between miR-497 and Yes-associated protein 1 (YAP1), respectively. NC mimic, miR-497 mimic, GACAT3-siRNA and NC inhibitor, GACAT3-siRNA and miR-497 inhibitor were co-transfected into U251 cells. Colony formation assay, flow cytometry and Western blot were adopted to evaluate the effect of miR-497 overexpression and lncRNA GACAT3 on the radiosensitivity of U251 cells by regulating miR-497.Results:Compared with NHA cells, the expression of lncRNA GACAT3 in U251 cells was significantly up-regulated, and the expression of miR-497 in U251 cells was significantly down-regulated (both P<0.05). After knockdown of GACAT3, the survival fraction of irradiated U251 cells was significantly decreased, while the apoptosis rate and Caspase-3 protein expression were significantly increased (all P<0.05). lncRNA GACAT3 targeted and negatively regulated the expression of miR-497. Overexpression of miR-497 significantly reduced the survival fraction of U251 cells after irradiation, and increased the apoptosis rate and Caspase-3 protein expression. Inhibition of miR-497 significantly reversed the promoting effect of lncRNA GACAT3 knockdown on the radiosensitivity of U251 cells. miR-497 targeted and negatively regulated the expression of YAP1. Conclusion:Knockdown of lncRNA GACAT3 can enhance the radiosensitivity of glioma cells by regulating the miR-497/YAP1 axis.

AIM: To establish a method for quantitation of cefepime and avibactam in M-H broth, and applicated in the in vitro dynamic PK/PD model. METHODS: The cefepime was also determined using the high-performance liquid chromatography method (HPLC), the avibactam was also determined using the liquid chromatography-mass spectrometry (LC-MS/MS), an in vitro dynamic PK/PD model was established to study the PK/PD relationship of cefepime/avibactam against carbapenem resistant Klebsiella pneumoniae (CRKP). RESULTS: The linear ranges of cefepime and avibactam were good at (0.5-20) and (0.1-25) μg/mL (r=0.999), and the lower limit concentrations were 0.5 and 0.1 μg/mL. The extraction recoveries of cefepime and avibactam in M-H broth were 88.0%-101.7% and 90.9%-95.2%, the relative standard deviation of intra-day precision and inter-day precision were less than 5.2%. The concentration-time curves were well simulated by the PK/PD model. All observed concentrations in each experiment were in the range of 20% of the targeted values. For the CRKP of MIC=8 μg/mL and MIC=16 μg/mL, the colony decreased to 2.783Log10 CFU/mL and 1.325Log10 CFU/mL at the cefepime/avibactam 2.5 g q8 h administration after 24 h. CONCLUSION: The determination method of cefepime and avibactam in broth established in this study has high sensitivity and good stability. For the CRKP with MIC≤8 μg/mL,cefepime/avibactam showed that good anti-CRKP activity under routine administration in vitro dynamic PK/PD model.

Objective To investigate the effects of edaravone on improving the prognosis of TBI rats.Methods A total of 150 SD male rats were divided into normal control group (10 rats),TBI group (70 rats) and edaravone group (70 rats).In the edaravone treatment group,the rats were injected intraperitoneally once a day continously for 2 weeks with the injection dose of 5.4 mg · kg-1 · d-1.At 6 hours,12 hours,24 hours,48 hours,72 hours,1 week and 2 weeks after injury,the neurobehavioral and motor function scores of rats were monitored respectively,with 10 rats monitored at each time point.Serum and cerebrospinal fluid samples were collected and the levels of β-endorphin and gonadotropin-releasing hormone (GnRH) were determined by radioimmunoassay (RIA).Results In the edaravone group,the neurobehavioral and motor function scores were higher than those of the TBI group at 6 hours,12 hours,24 hours,48 hours,72 hours,1 week and 2 weeks after injury.At 48 hours after injury,the neurobehavioral scores of the TBI group and the edaravone treatment group were (8.2 ±0.9) points and (10.3 ±0.7) points,respectively (P ＜ 0.05),and the motor function scores were (5.9 ± 1.0) points and (6.9 ± 1.2) points respectively (P ＜ 0.05).Meanwhile,the contents of β-endorphin in blood and cerebrospinal fluid of the normal control group were (50.2 ± 9.5) pg/ml and (16.2 ± 2.8) pg/ml,and the contents of GnRH were (75.2 ± 11.2) pg/ml and (36.2 ± 10.8)pg/ml,respectively.The levels of β-endorphin and GnRH in serum and cerebrospinal fluid were significantly increased at 6 hours,12 hours,24 hours,48 hours,72 hours,l week and 2 weeks after injury.The levels of β-endorphin and GnRH in the edaravone group were lower than those of TBI group.At 72 hour after injury,the levels of β-endorph in serum in TBI group and edaravone group were (165.2 ± 8.5) pg/ml and (109.5 ± 6.3) pg/ml respectively (P ＜ 0.05),and the levels of β-endorph in cerebrospinal fluid were (63.3 ± 3.1) pg/ml and (38.2 ± 2.3) pg/ml respectively (P ＜ 0.05).At 72 hour after injury,the levels of GnRH in serum in TBI group and edaravone group were (203.7 ± 17.1)pg/ml and (110.4 ± 19.2)pg/ml respectively (P ＜0.05),and the levels of GnRH in cerebrospinal fluid is (153.0 ± 13.4) pg/ml and (93.2 ± 10.5) pg/ml respectively (P ＜ 0.05).Conclusion During acute and recovery periods after TBI,continuous treatment with edaravone can obviously reduce the levels of β-endorphin and GnRH,which is beneficial to alleviate the secondary brain injury after TBI in rats,promote the recovery of nerve and function,and improve the prognosis.

Objective To observe the changes in functional connectivity(FC)of raphe nucleus in patients with first-episode depression complicated with suicidal ideation(SI).Methods Ninety-eight first-episode depression patients were prospectively enrolled and assigned into SI group(n=56)or non SI group(n=42)based on complicated with SI or not,while 47 healthy volunteers were recruited as control group.Resting-state functional MRI was performed.FC between dorsal raphe nucleus(DRN),median raphe nucleus(MRN)and the whole brain were analyzed and compared among 3 groups and between each 2 groups,and the correlations of FC of different brain regions with clinical data of SI group were explored.Results Compared with control group,FC between DRN and left cerebellum and left putamen in SI group and non SI group decreased(all P＜0.05),between MRN and right inferior temporal gyrus increased but between MRN and left inferior frontal gyrus,right superior occipital gyrus,left inferior parietal lobule,left putamen decreased(all P＜0.05).FC between DRN and left putamen in SI group was higher than that in non SI group(P＜0.05).FC between MRN and right central posterior gyrus of SI group increased compared with that in the rest 2 groups(both P＜0.05).FC between MRN and left putamen in SI group was positively correlated with body mass score of Hamilton depression scale-24(HAMD-24)(rs=0.297,P=0.026).Conclusion Abnormal changes of FC between raphe nucleus and cortex,also between raphe nucleus and subcortical area occurred,and FC between MRN and left putamen positively correlated with body mass score of HAMD-24 in patients with first-episode depression complicated with SI.

Monotropein is a compound classified into iridoid which is found in herbaceous plants Morindae officinalis. It possesses anti-inflammatory, antioxidant, and anti-osteoarthritic activities. Previous study indicates that monotropein may have the potential to combat cardiovascular disease, although the related mechanism remains unclear. In this study, we constructed the model of atherosclerosis by oxidized low density lipoprotein-induced vascular smooth muscle cells and LDLR –/–mice given high-fat diet to investigate the effects of monotropein on atherosclerosis.Our results showed that monotropein treatment significantly reduced the area of atherosclerotic plaques and necrotic cores in mice, inhibited the proliferation and migration of vascular smooth muscle cells, and reduced inflammatory responses and oxidative stress, which in turn alleviated atherosclerosis. In addition, we found that monotropein reduced the expression levels of P-NF-κB and P-AP-1. In conclusion, our data suggest that monotropein inhibited the proliferation and migration of vascular smooth muscle cells by mediating the activity of NF-κB, AP-1, reducing the level of inflammation and oxidative stress, and thus resisting the development of atherosclerosis. These findings demonstrate the efficacious therapeutic impact of monotropein on atherosclerosis and elucidate its specific target.

Monotropein is a compound classified into iridoid which is found in herbaceous plants Morindae officinalis. It possesses anti-inflammatory, antioxidant, and anti-osteoarthritic activities. Previous study indicates that monotropein may have the potential to combat cardiovascular disease, although the related mechanism remains unclear. In this study, we constructed the model of atherosclerosis by oxidized low density lipoprotein-induced vascular smooth muscle cells and LDLR –/–mice given high-fat diet to investigate the effects of monotropein on atherosclerosis.Our results showed that monotropein treatment significantly reduced the area of atherosclerotic plaques and necrotic cores in mice, inhibited the proliferation and migration of vascular smooth muscle cells, and reduced inflammatory responses and oxidative stress, which in turn alleviated atherosclerosis. In addition, we found that monotropein reduced the expression levels of P-NF-κB and P-AP-1. In conclusion, our data suggest that monotropein inhibited the proliferation and migration of vascular smooth muscle cells by mediating the activity of NF-κB, AP-1, reducing the level of inflammation and oxidative stress, and thus resisting the development of atherosclerosis. These findings demonstrate the efficacious therapeutic impact of monotropein on atherosclerosis and elucidate its specific target.

Monotropein is a compound classified into iridoid which is found in herbaceous plants Morindae officinalis. It possesses anti-inflammatory, antioxidant, and anti-osteoarthritic activities. Previous study indicates that monotropein may have the potential to combat cardiovascular disease, although the related mechanism remains unclear. In this study, we constructed the model of atherosclerosis by oxidized low density lipoprotein-induced vascular smooth muscle cells and LDLR –/–mice given high-fat diet to investigate the effects of monotropein on atherosclerosis.Our results showed that monotropein treatment significantly reduced the area of atherosclerotic plaques and necrotic cores in mice, inhibited the proliferation and migration of vascular smooth muscle cells, and reduced inflammatory responses and oxidative stress, which in turn alleviated atherosclerosis. In addition, we found that monotropein reduced the expression levels of P-NF-κB and P-AP-1. In conclusion, our data suggest that monotropein inhibited the proliferation and migration of vascular smooth muscle cells by mediating the activity of NF-κB, AP-1, reducing the level of inflammation and oxidative stress, and thus resisting the development of atherosclerosis. These findings demonstrate the efficacious therapeutic impact of monotropein on atherosclerosis and elucidate its specific target.

Monotropein is a compound classified into iridoid which is found in herbaceous plants Morindae officinalis. It possesses anti-inflammatory, antioxidant, and anti-osteoarthritic activities. Previous study indicates that monotropein may have the potential to combat cardiovascular disease, although the related mechanism remains unclear. In this study, we constructed the model of atherosclerosis by oxidized low density lipoprotein-induced vascular smooth muscle cells and LDLR –/–mice given high-fat diet to investigate the effects of monotropein on atherosclerosis.Our results showed that monotropein treatment significantly reduced the area of atherosclerotic plaques and necrotic cores in mice, inhibited the proliferation and migration of vascular smooth muscle cells, and reduced inflammatory responses and oxidative stress, which in turn alleviated atherosclerosis. In addition, we found that monotropein reduced the expression levels of P-NF-κB and P-AP-1. In conclusion, our data suggest that monotropein inhibited the proliferation and migration of vascular smooth muscle cells by mediating the activity of NF-κB, AP-1, reducing the level of inflammation and oxidative stress, and thus resisting the development of atherosclerosis. These findings demonstrate the efficacious therapeutic impact of monotropein on atherosclerosis and elucidate its specific target.