BACKGROUND:Titanium surface micro-nano structure modification is a hot research field in titanium implant surface treatment.The diabetic hyperglycemia environment will affect the stable bonding between titanium implant and bone tissue,so it is necessary to explore the surface micro-nano structure modification to improve the osteogenic activity of titanium implant in high glucose environment.OBJECTIVE:To investigate the effect of gold nanoparticle@mesoporous silica nanoparticles(AuNPs@MSNs)coating on osteogenic activity of osteoblasts under high glucose in vitro.METHODS:Gold nanoparticle suspension and mesoporous silica were prepared respectively,and the two were mixed in deionized water in a certain proportion to prepare gold nanoparticle@mesoporous silica suspension.Titanium sheets were taken and divided into three groups for treatment:the smooth group was treated with water sandpaper;the nanotube group was treated with water sandpaper and then anodized to prepare titanium dioxide nanotube coating,and the experimental group prepared titanium dioxide nanotube coating and then immersed in gold nanoparticle@mesoporous silica suspension to prepare gold nanoparticle@mesoporous silica nanoparticles coating.The microscopic morphology and hydrophilicity of the surface of the three groups of titanium sheets were characterized.Rat bone marrow mesenchymal stem cells were inoculated on the surface of the three groups of titanium sheets.Cell proliferation was detected by cell live/dead fluorescence staining and CCK-8 assay.Cell adhesion was detected by DAPI/phalloidin staining.Rat bone marrow mesenchymal stem cells were inoculated on the surface of the three groups of titanium sheets,and high-glucose osteogenic induction medium was added for culture.Osteogenic differentiation was detected by alkaline phosphatase and Alizarin Red S staining.RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of the titanium sheet in the smooth group was uniform and flat.The titanium dioxide nanotube arrays in the nanotube group were closely arranged on the surface,and the titanium sheet in the experimental group was loaded with gold nanoparticle@mesoporous silica on the surface and inside of the titanium dioxide nanotubes.The hydrophilicity of the titanium sheets in the nanotube group and the experimental group was better than that in the smooth group.(2)The results of cell live/dead fluorescence staining exhibited that the cell viability on the surface of the three groups of titanium sheets was higher than 90%.The results of CCK-8 assay show that the cell proliferation rate in the experimental group was higher than that in the smooth group and the nanotube group.The results of DAPI/phalloidin staining showed that the titanium dioxide nanotube coating and the gold nanoparticle@mesoporous silica nanoparticles coating were more conducive to cell adhesion.(3)The results of alkaline phosphatase and Alizarin Red S staining showed that the alkaline phosphatase activity and extracellular matrix mineralization of the cells on the titanium sheet surface in the experimental group were higher than those in the smooth group and the nanotube group.(4)The results show that the gold nanoparticle@mesoporous silica nanoparticles coating can enhance the biological activity of the titanium surface and promote osteogenic differentiation in a high glucose environment.

BACKGROUND:Titanium surface micro-nano structure modification is a hot research field in titanium implant surface treatment.The diabetic hyperglycemia environment will affect the stable bonding between titanium implant and bone tissue,so it is necessary to explore the surface micro-nano structure modification to improve the osteogenic activity of titanium implant in high glucose environment.OBJECTIVE:To investigate the effect of gold nanoparticle@mesoporous silica nanoparticles(AuNPs@MSNs)coating on osteogenic activity of osteoblasts under high glucose in vitro.METHODS:Gold nanoparticle suspension and mesoporous silica were prepared respectively,and the two were mixed in deionized water in a certain proportion to prepare gold nanoparticle@mesoporous silica suspension.Titanium sheets were taken and divided into three groups for treatment:the smooth group was treated with water sandpaper;the nanotube group was treated with water sandpaper and then anodized to prepare titanium dioxide nanotube coating,and the experimental group prepared titanium dioxide nanotube coating and then immersed in gold nanoparticle@mesoporous silica suspension to prepare gold nanoparticle@mesoporous silica nanoparticles coating.The microscopic morphology and hydrophilicity of the surface of the three groups of titanium sheets were characterized.Rat bone marrow mesenchymal stem cells were inoculated on the surface of the three groups of titanium sheets.Cell proliferation was detected by cell live/dead fluorescence staining and CCK-8 assay.Cell adhesion was detected by DAPI/phalloidin staining.Rat bone marrow mesenchymal stem cells were inoculated on the surface of the three groups of titanium sheets,and high-glucose osteogenic induction medium was added for culture.Osteogenic differentiation was detected by alkaline phosphatase and Alizarin Red S staining.RESULTS AND CONCLUSION:(1)Scanning electron microscopy showed that the surface of the titanium sheet in the smooth group was uniform and flat.The titanium dioxide nanotube arrays in the nanotube group were closely arranged on the surface,and the titanium sheet in the experimental group was loaded with gold nanoparticle@mesoporous silica on the surface and inside of the titanium dioxide nanotubes.The hydrophilicity of the titanium sheets in the nanotube group and the experimental group was better than that in the smooth group.(2)The results of cell live/dead fluorescence staining exhibited that the cell viability on the surface of the three groups of titanium sheets was higher than 90%.The results of CCK-8 assay show that the cell proliferation rate in the experimental group was higher than that in the smooth group and the nanotube group.The results of DAPI/phalloidin staining showed that the titanium dioxide nanotube coating and the gold nanoparticle@mesoporous silica nanoparticles coating were more conducive to cell adhesion.(3)The results of alkaline phosphatase and Alizarin Red S staining showed that the alkaline phosphatase activity and extracellular matrix mineralization of the cells on the titanium sheet surface in the experimental group were higher than those in the smooth group and the nanotube group.(4)The results show that the gold nanoparticle@mesoporous silica nanoparticles coating can enhance the biological activity of the titanium surface and promote osteogenic differentiation in a high glucose environment.

Objective:To evaluate the efficacy and outcomes of early removal of lumen-apposing metal stent (LAMS) in the treatment of pancreatic wall-off necrosis (WON).Methods:A retrospective analysis was performed on 51 patients with WON who underwent endoscopic ultrasound (EUS)-guided transluminal drainage (ETD) and direct endoscopic necrosectomy (DEN) using LAMS at Nanjing Drum Tower Hospital from January 2018 to December 2022. Patients were divided into the early removal group (within two weeks, n=24) and the traditional removal group (after two weeks, n=27) based on the timing of LAMS removal. The short-term effects, safety and long-term outcomes of WON were compared between the two groups. Results:The technical success rate of LAMS placement in 51 patients reached 100%, and all patients underwent ETD and DEN. The median number of necrosectomy sessions in the early removal group was significantly lower than in the traditional removal group, 2.0 sessions vs 3.0 sessions and the difference was statistically significant ( P<0.05). Postoperatively, 15.7% of patients required percutaneous catheter drainage (PCD) and 5.9% required surgery, with no significant difference between the two groups. The clinical success rate and mortality rate in the early removal group were 79.2% and 8.3%, respectively, compared to 81.5% and 3.7% in the traditional removal group, with no statistically significant difference. In terms of safety, the early removal group exhibited a significantly lower rate of adverse events during stent retention with statistically significant difference (12.5% vs 37.0%, P<0.05) compared to the traditional removal group. A total of 46 patients were followed up for six months. In the early removal group, the rates of disease recurrence, need for endoscopic reintervention and occurrence of long-term complications were 20.0%, 10.0% and 20.0%, respectively. These rates did not show a significant increase compared to the traditional removal group, which were 7.7%, 3.8% and 38.5%, respectively, without significant differences between the groups. Conclusions:In the treatment of WON, early removal of LAMS is safe and effective to a certain extent. In comparison to the traditional practice of removing LAMS after two weeks, early removal does not reduce clinical success rates, nor does it increase the rates of disease-related mortality, recurrence, or long-term complications. On the contrary, it may reduce the occurrence of adverse events during stent retention and decrease the number of necrosectomy procedures subsequently.

Objective:To identify the differentially expressed long-chain non-coding RNA(lncRNA) and mRNA using ribonucleic acid sequencing(RNA-seq), and construct a competing endogenous RNA(ceRNA) regulatory network in mice with sepsis-associated encephalopathy.Methods:Ten clean-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 20-25 g, were divided into 2 groups( n=5 each) using a random number table method: sham operation group(group Sham) and sepsis group(group Sepsis). Sepsis was induced by cecal ligation and puncture(CLP) in group Sepsis, while group Sham only underwent laparotomy without CLP. Morris water maze test and contextual fear conditioning test were performed to detect the cognitive function on 1 day before CLP and 3 days after CLP. Three mice were randomly sacrificed in group Sham, and 3 mice with the worst results in the cognitive function test were sacrificed in group Sepsis. The hippocampal tissues were obtained for RNA-seq via the BGISEQ-500 platform, and the differentially expressed mRNA and lncRNA were identified. The differentially expressed mRNAs and lncRNAs were visualized and analyzed by Dr. Tom platform provided by Shenzhen BGI Technology Service Co., Ltd., and the ceRNA regulatory network was constructed using the online visualization tool Cytoscape software. Results:Compared with group Sham, the escape latency was significantly prolonged, and the percentage of time of staying at the target quadrants and percentage of time spent freezing were decreased in group Sepsis( P<0.05). A total of 62 differentially expressed lncRNAs were obtained from RNA-seq, of which the expression of 45 lncRNAs was up-regulated and the expression of 17 lncRNAs was down-regulated.There were 282 differentially expressed mRNAs identified from RNA-seq, of which the expression of 173 mRNAs was up-regulated, and the expression of 109 mRNAs was down-regulated.Gene Ontology enrichment analysis revealed that the differentially expressed mRNAs were involved in biological processes such as memory, learning or memory, inflammatory responses, regulation of aging-related behavioral decline, and regulation of synaptic plasticity. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis showed that differentially expressed mRNAs were enriched in IL-17 signaling pathway, TNF signaling pathway, NF-κB signaling pathway and etc. KDA analysis was performed on the differentially expressed mRNAs to identify the key driver genes, and the results showed that Ch25h, Il6ra, Lcn2, Sgk1, Nr4a3, Osm, Saa3, Ccl7, Sqle, Dhcr24 were the key SAE genes.A competing endogenous RNA regulatory network was successfully constructed based on 9 lncRNAs, 28 mRNAs and 134 miRNAs in the hippocampus of mice with SAE. Conclusions:The results of RNA-seq find that 10 mRNAs including Ch25h, Il6ra, Lcn2, Sgk1, Nr4a3, Osm, Saa3, Ccl7, Sqle, Dhcr24 and lncRNAs such as Rian, Gm35874 and Gm34347 are key genes regulating SAE in mice. Meanwhile, a ceRNA regulatory network based on lncRNA-miRNA-mRNA is successfully constructed in the hippocampus of mice with SAE.

Objective:To evaluate the effect of dexmedetomidine on the expression of DNA methyltransferases in septic mice with acute lung injury.Methods:Forty-eight clean-grade healthy male C57BL/6 mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (group Sham), sham operation + dexmedetomidine group(group Sham+ DEX), sepsis group (group Sepsis) and sepsis + dexmedetomidine group(group Sepsis+ DEX). Sepsis model was established by cecal ligation and puncture(CLP)in anesthetized mice. At 30 min before model preparation, dexmedetomidine 0.05 μg/g (in 0.5 ml of normal saline) was administered in Sham + DEX and Sepsis + DEX groups, and normal saline 0.5 ml was given instead in Sham and Sepsis groups. The mice were sacrificed at 24 h after CLP, and the lung tissue was taken to determine the wet to dry lung weight ratio, contents of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and high mobility group box-1 (HMGB-1), activities of superoxide dismutase (SOD) and myeloperoxidase (MPO), and content of malondialdehyde (MDA) (by enzyme-linked immunosorbent assay), global DNA methylation (by colorimetric assay), and expression of DNA methyltransferases (DNMTl, DNMT3a, DNMT3b) (by Western blot) and to examine the histopathological changes of lung tissues (by HE staining) which were scored. Results:Compared with group Sham, the lung injury score, wet/dry lung weight ratio, contents of IL-6, TNF-α and HMGB1 and MDA, MPO activity and global DNA methylation were significantly increased, SOD activity was decreased, and the expression of DNMT1 and DNMT3a was up-regulated in group Sepsis and group Sepsis+ DEX ( P<0.05), and no significant change was found in the aforementioned indexes in group Sham+ DEX ( P>0.05). Compared with group Sepsis, the lung injury score, wet/dry lung weight ratio, contents of IL-6, TNF-α and HMGB1 and MDA, MPO activity and global DNA methylation were significantly decreased, SOD activity was increased, and the expression of DNMT1 and DNMT3a was down-regulated in group Sepsis+ DEX ( P<0.05). Conclusions:The mechanism by which dexmedetomidine reduces acute lung injury is related to inhibition of up-regulation of DNMT1 and DNMT3a expression in septic mice.

Objective:To evaluate the role of DNA methyltransferase in acute lung injury in septic mice.Methods:Forty-eight healthy male C57BL/6 mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=12 each) using a random number table method: sham operation group (group Sham), sham operation+ DNA methyltransferase inhibitor group (group Sham+ 5-Aza), sepsis group (group Sepsis) and sepsis+ DNA methyltransferase inhibitor group (group Sepsis+ 5-Aza). Sepsis model was developed by cecal ligation and puncture (CLP) in anesthetized mice.Mice were sacrificed at 24 h after CLP, and lung tissues were obtained, DNA was extracted to determine the global DNA methylation by colorimetry, and RNA was extracted to detect the expression of DNA methyltransferase (DNMTl, DNMT3a, DNMT3b) mRNA by real-time fluorescent quantitative polymerase chain reaction, the wet/dry lung weight ratio (W/D ratio) was measured, the histopathological changes of lung tissues were determined by HE staining, the contents of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), high-mobility group box 1 protein (HMGB1) and malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and catalase were measured by enzyme-linked immunosorbent assay. Results:Compared with group Sham, the global DNA methylation was significantly increased, the expression of DNMT1 and DNMT3a mRNA was up-regulated, the lung injury score, W/D ratio, and contents of IL-6, TNF-α, HMGB1 and MDA were increased, and activities of SOD and CAT were decreased at 24 h after CLP in group Sepsis and group Sepsis+ 5-Aza ( P<0.05), and no significant change was found in the indexes mentioned above in group Sham+ 5-Aza ( P>0.05). Compared with group Sepsis, the global DNA methylation was significantly decreased, the expression of DNMT1 and DNMT3a mRNA was down-regulated, the lung injury score, W/D ratio, contents of IL-6, TNF-α, HMGB1 and MDA were decreased, and the activities of SOD and CAT were increased in group Sepsis+ 5-Aza ( P<0.05). Conclusions:DNA hypermethylation mediated by DNMT1 and DNMT3a is involved in the process of acute lung injury in septic mice.

Objective:To evaluate the effect of hydrogen-rich saline on serine threonine protein kinase (Akt) /nuclear factor E2-related factor 2 (Nrf2) signaling pathway during hypoxia/reoxygenation (H/R) injury to human renal tubular epithelial cells.Methods:Human renal tubular epithelial cell line were seeded in 96-well plates at a density of 1.5×10 4 cells/ml (200 μl/well) or in 6-well plates at a density of 2×10 5 cells/ml (2 ml/well) were divided into 5 groups( n=30 each) using a random number table method: control group (group C), hydrogen-rich group (group H), group H/R, H/R plus hydrogen-rich saline group (group H/R+ H) and H/R plus hydrogen-rich saline plus Akt inhibitor uprosertib group (group H/R+ H+ U) .In group C, the cells were incubated for 28 h in an incubator filled with normoxia at 37 ℃ (5%CO 2-21%O 2-74%N 2). In group H, cells were added to the medium containing 0.6 mmol/L hydrogen-rich saline, and then incubated for 28 h in an incubator filled with normoxia at 37 ℃.In group H/R, the cells were incubated in an anaerobic chamber (37 ℃, 5%CO 2-1%O 2-94 %N 2) for 24 h, and then incubated for 4 h in an incubator filled with normoxia at 37 ℃.In group H/R+ H, the cells were incubated in an anaerobic chamber for 24 h, and then incubated for 4 h in an incubator containing 0.6 mmol/L filled with normoxia at 37 ℃.In group H/R+ H+ U, the cells were incubated for 1 h in the culture medium containing uprosertib 10 μmol/L (final concentration) and the other treatments were similar to those previously described in group H/R+ H. After treatment in each group, the cell viability was measured by MTT assay, cell apoptosis was measured using flow cytometry, superoxide dismutase (SOD) activity was measured using xanthine oxidase method), malondialdehyde (MDA) content was detected by thiobarbituric acid method, the expression of Akt, phosphorylated Akt (p-Akt), total Nrf2, nuclear Nrf2 and activated caspase-3 was detected by Western blot, and the expression of Nrf2 mRNA was detected by Real-time PCR. Results:Compared with group C, the cell viability and activity of SOD were significantly decreased, the apoptosis rate and content of MDA were increased, and the expression of p-Akt, nuclear Nrf2, total Nrf2, activated caspase-3 protein and Nrf2 mRNA was up-regulated in group H/R and group H/R+ H ( P<0.05). Compared with group H/R, the cell viability and activity of SOD were significantly increased, the apoptosis rate and content of MDA were decreased, the expression of p-Akt, nuclear Nrf2, total Nrf2 and Nrf2 mRNA was up-regulated and expression of activated caspase-3 protein was down-regulated in group H/R+ H ( P<0.05). Compared with group H/R+ H, the cell viability and activity of SOD was significantly decreased, the apoptosis rate and content of MDA were increased, the expression of p-Akt, nuclear Nrf2, total Nrf2 protein and Nrf2m RNA was down-regulated, and the expression of activated caspase-3 protein was up-regulated in group H/R+ H+ U ( P<0.05). Conclusion:The mechanism by which hydrogen-rich saline attenuates H/R injury to human renal tubular epithelial cells is related to improving activation of Akt/Nrf2 signaling pathway, decreasing oxidative stress response and inhibiting cell apoptosis.

Objective:To evaluate the role of nuclear factor erythroid 2-related factor/ heme oxygenase-1 (Nrf2/HO-1) signaling pathway in dexmedetomidine-induced reduction of oxygen-glucose deprivation and restoration (OGD/R) injury to microglia.Methods:BV-2 microglia were cultured in high-glucose DMEM culture medium supplemented with 10% fetal bovine serum in an normal culture incubator at 37 ℃ (5%CO 2-21%O 2-74 %N 2). The cells were seeded in 96-well plates at a density of 1.5×10 4 cells/ml (200 μl/well) or 6-well plates at a density of 2×10 5 cells/ml (2 ml/well) and divided into 5 groups ( n=30 each) using a random number table method: control group (group C), dexmedetomidine group (group D), group OGD/R, OGD/R+ dexmedetomidine group (group OGD/R+ D) and OGD/R+ dexmedetomidine+ ML385 group (group OGD/R+ D+ ML). The cells in group C were continuously cultured in a normal culture incubator for 26 h. In group D, dexmedetomidine at the final concentration of 10 μmol/L was added, cells were incubated for 2 h, and then were continuously incubated in a normal culture incubator for 26 h. In OGD/R, OGD/R+ D and OGD/R+ D+ ML groups, the culture medium was replaced with glucose-free DMEM culture medium, cells were cultured for 2 h in an incubator at 37 ℃ (5%CO 2-1%O 2-94 %N 2), the culture medium was replaced with high-glucose DMEM culture medium containing 10% fetal bovine serum and then the cells were cultured for 24 h in a normal incubator.Dexmedetomidine at the final concentration of 10 μmol/L was added at 2 h before OGD in OGD/R+ D and OGD/R+ D+ ML groups.Nrf-2 inhibitor ML385 at the final concentration of 4 μmol/L was added at 30 min before dexmedetomidine was added in group OGD/R+ D+ ML.Cells in 6 wells in each group were selected randomly for assessment of cell viability (by methyl thiazolyl tetrazolium assay) and apoptosis (using flow cytometry), and for determination of the concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the supernatant (using enzyme-linked immunosorbent assay), the expression of Nrf2 in nucleus, Nrf2 and HO-1(by Western blot ) and the expression of HO-1 mRNA (by real-time polymerase chain reaction). Results:Compared with group C, the cell viability was significantly decreased, cell apoptosis rate and concentrations of TNF-α, IL-6 and IL-10 in the supernatant were increased, and the expression of Nrf2 in nucleus, Nrf2, HO-1 and its mRNA was up-regulated in OGD/R and OGD/R+ D groups ( P<0.05), and no significant change was found in each parameter mentioned above in group D ( P>0.05). Compared with group OGD/R, the cell viability and IL-10 in the supernatant concentration were significantly increased, cell apoptosis rate and concentrations of TNF-α and IL-6 in the supernatant were decreased and the expression of Nrf2 in nucleus, Nrf2, HO-1 and its mRNA was up-regulated in group OGD/R+ D ( P<0.05), and no significant changes were found in the parameters mentioned above in group OGD/R+ D+ ML ( P>0.05). Compared with group OGD/R+ D, the cell viability and concentration of IL-10 in the supernatant were significantly decreased, cell apoptosis rate and concentrations of TNF-α and IL-6 in the supernatant were increased and the expression of Nrf2 in nucleus, Nrf2, HO-1 and its mRNA was down-regulated in group OGD/R+ D+ ML ( P<0.05). Conclusion:The mechanism by which dexmedetomidine alleviates OGD/R injury to microglia may be related to promoting the activation of Nrf2/HO-1 signaling pathway and inhibition of inflammatory responses.

The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.
Animals ; Cell Differentiation ; Flavanones ; Mice ; Mice, Inbred C57BL ; Myelin Sheath/metabolism* ; Oligodendroglia/metabolism* ; Rats ; Remyelination ; Signal Transduction ; TOR Serine-Threonine Kinases/metabolism*

The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.