BACKGROUND:The extracellular-regulated protein kinase 5(ERK5)signaling protein is essential for the survival of organisms,and resveratrol can promote osteoblast proliferation through various pathways.However,whether resveratrol can regulate osteoblast function through the ERK5 signaling protein needs further verification. OBJECTIVE:To explore the regulatory effect of ERK5 on the proliferation of MC3T3-E1 cells and related secreted proteins,and to further verify whether resveratrol can complete the above process by activating ERK5. METHODS:Mouse MC3T3-E1 preosteoblasts were treated with complete culture medium,XMD8-92(an ERK5 inhibitor),epidermal growth factor(an ERK5 activator),resveratrol alone,XMD8-92+EGF,and resveratrol+XMD8-92,respectively.Western blot assay was used to detect the expression of ERK5 and p-ERK5 proteins,proliferation-related proteins Cyclin D1,CDK4 and PCNA,and osteoblast-secreted proteins osteoprotegerin and receptor activator of nuclear factor-κB ligand in MC3T3-E1 cells of each group.The fluorescence intensity of ERK5,osteoprotegerin and receptor activator of nuclear factor-κB ligand in each group was detected by cell immunofluorescence staining,and cell proliferation was detected by EdU staining,respectively.The appropriate concentration and time of resveratrol intervention in MC3T3-E1 cells were determined by cell morphology observation and cell counting kit-8 assay. RESULTS AND CONCLUSION:The activation of ERK5 signaling protein could effectively promote the proliferation of MC3T3-E1 cells,up-regulate the osteoprotegerin/receptor activator of nuclear factor-κB ligand ratio.The appropriate concentration and time for resveratrol intervention in MC3T3-E1 cells was 5 μmol/L and 24 hours,respectively.Resveratrol could activate ERK5 signaling protein,thereby promoting osteoblast proliferation and up-regulating the osteoprotegerin/RANKL ratio.All these results indicate that resveratrol can promote the proliferation of MC3T3-E1 cells and up-regulate the osteoprotegerin/RANKL ratio by activating the ERK5 signaling protein.

BACKGROUND:The imbalance between bone resorption and bone formation in microgravity environments leads to significant bone loss in astronauts.Current research indicates that bone loss under microgravity conditions is the result of the combined effects of various cells,tissues,and systems. OBJECTIVE:To review different biological effects of microgravity on various cells,tissues,or systems,and summarize the mechanisms by which microgravity leads to the development of osteoporosis. METHODS:Databases such as PubMed,Web of Science,and the Cochrane Database were searched for relevant literature from 2000 to 2023.The inclusion criteria were all articles related to tissue engineering studies and basic research on osteoporosis caused by microgravity.Ultimately,85 articles were included for review. RESULTS AND CONCLUSION:(1)In microgravity environment,bone marrow mesenchymal stem cells tend to differentiate more into adipocytes rather than osteoblasts,and hematopoietic stem cells in this environment are more inclined to differentiate into osteoclasts,reducing differentiation into the erythroid lineage.At the same time,microgravity inhibits the proliferation and differentiation of osteoblasts,promotes apoptosis of osteoblasts,alters cell morphology,and reduces the mineralization capacity of osteoblasts.Microgravity significantly increases the number and activity of osteoclasts.Microgravity also hinders the differentiation of osteoblasts into osteocytes and promotes the apoptosis of osteocytes.(2)In a microgravity environment,the body experiences changes such as skeletal muscle atrophy,microvascular remodeling,bone microcirculation disorders,and endocrine disruption.These changes lead to mechanical unloading in the bone microenvironment,insufficient blood perfusion,and calcium cycle disorders,which significantly impact the development of osteoporosis.(3)At present,the mechanism by which microgravity causes osteoporosis is relatively complex.A deeper study of these physiological mechanisms is crucial to ensuring the health of astronauts during long-term space missions,and provides a theoretical basis for the prevention and treatment of osteoporosis.

Alzheimer's disease (AD) is a leading cause of dementia in the elderly. Mitogen-activated protein kinase phosphatase 1 (MKP-1) plays a neuroprotective role in AD. However, the molecular mechanisms underlying the effects of MKP-1 on AD have not been extensively studied. MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level, thereby repressing mRNA translation. Here, we reported that the microRNA-429-3p (miR-429-3p) was significantly increased in the brain of APP23/PS45 AD model mice and N2A^APP AD model cells. We further found that miR-429-3p could downregulate MKP-1 expression by directly binding to its 3'-untranslated region (3' UTR). Inhibition of miR-429-3p by its antagomir (A-miR-429) restored the expression of MKP-1 to a control level and consequently reduced the amyloidogenic processing of APP and Aβ accumulation. More importantly, intranasal administration of A-miR-429 successfully ameliorated the deficits of hippocampal CA1 long-term potentiation and spatial learning and memory in AD model mice by suppressing extracellular signal-regulated kinase (ERK1/2)-mediated GluA1 hyperphosphorylation at Ser831 site, thereby increasing the surface expression of GluA1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs). Together, these results demonstrate that inhibiting miR-429-3p to upregulate MKP-1 effectively improves cognitive and synaptic functions in AD model mice, suggesting that miR-429/MKP-1 pathway may be a novel therapeutic target for AD treatment.

ObjectiveTo quantitatively investigate the changes in the total volume and contour density of hepatic oval cells （HOC） in hepatic lobules of rats with carbon tetrachloride （CCl₄）-induced hepatic fibrosis. MethodsA total of 11 healthy male Sprague-Dawley rats were randomly divided into control group with 5 rats and hepatic fibrosis group with 6 rats， and CCl₄ and olive oil suspension were injected subcutaneously twice a week， 3 mL/kg each time. After five weeks of hepatic fibrosis modeling， five liver tissue blocks with a size of about 1 mm³ were randomly selected from the liver of each rat to prepare one Epon812 epoxy resin-embedded ultrathin section， and the stereological method and transmission electron microscopy were used for the quantitative analysis of the total volume and contour density of HOC in the hepatic lobules of rats. In addition， four liver tissue blocks with a thickness of 2 mm were randomly selected from the remaining liver of each rat to prepare two paraffin-embedded Masson staining sections， and the degree of liver fibrosis in each rat was qualitatively evaluated according to the Metavir staging criteria for liver fibrosis. The independent-samples t test was used for comparison of continuous data between groups. ResultsThe quantitative stereological analysis showed that the total volume of HOC in hepatic lobules was 15.40±7.63 mm³ in the control group and 146.80±114.00 mm³ in the liver fibrosis group， and compared with the control group， the total volume of HOC in hepatic lobules of rats in the liver fibrosis group was significantly increased by 8.53 times （t=-2.551， P=0.031）； the contour density of HOC in hepatic lobules was 56.20±40.40 in the control group and 566.50±317.00 in the liver fibrosis group， and compared with the control group， the contour density of HOC in hepatic lobules of rats in the liver fibrosis group was significantly increased by 9.08 times （t=-3.539， P=0.006）. Qualitative observation showed that liver fibrosis stage of rats reached stage Ⅱ-Ⅲ according to the Metavir scoring criteria， and massive proliferation of HOC was observed around the proliferation site of hepatic stellate cells in the perisinusoidal space of rats. ConclusionCCl₄ induces significant proliferation of HOC in hepatic lobules of rats with liver fibrosis.

Qualitative analysis of the ingredients absorbed into blood and their metabolites of Xihuang pill (XHP) were conducted using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-Q-TOF-MS/MS) technology. Network pharmacology was used to explore the potential anticancer mechanisms of the ingredients against glioma, and their specific mechanisms were validated through molecular docking and experimental verification. SD rats were intragastrically administered with XHP, and rat serum samples were collected. Ingredients absorbed into blood and their metabolites were identified based on the retention time of chromatographic peaks, accurate molecular mass, characteristic fragment ions, and comparisons with reference substances and literature data. PharmMapper and SwissTarget Prediction databases were used to obtain the targets of the XHP-medicated serum, while GeneCards, OMIM, PharmGKB, TTD, and DrugBank databases were used to obtain glioma disease targets. The "component-target" network relationship diagram was constructed using Cytoscape 3.9.1 software. The protein-protein interaction (PPI) network diagram was constructed using the STRING database, and the targets were analyzed using GO and KEGG analyses. Molecular docking was used to verify the binding ability of core targets with their corresponding compounds in XHP-medicated serum. The potential mechanism of the anti-glioma effect of 11-keto-β-boswellic acid (KBA), a representative component of XHP-medicated serum, was verified using CCK-8 and Western blot assays. A total of 40 compounds were identified in the XHP-medicated serum, including 28 prototype components and 12 metabolites. The network pharmacology results showed that elemonic acid, 3-acetyl-β-boswellic acid, KBA, α-boswellic acid, and other 5 compounds might be the active ingredients of XHP-medicated serum in the treatment of glioma. Glutathione reductase (GSR), glucose-6-phosphate dehydrogenase (G6PD), ATP-citrate lyase (ACLY), aldo-keto reductase family 1 member B1 (AKR1B1) and glutaredoxin (GLRX) were identified as key targets, involving pathways such as glutathione metabolism and the pentose phosphate pathway. Further cell experiments showed that KBA significantly inhibited the proliferation of T98G cells with an IC₅₀ of 30.96 μmol·L^-1, and KBA (30 μmol·L^-1) significantly downregulated the protein expression levels of GSR in T98G cells. In summary, XHP-medicated serum may exert its anti-glioma effect by regulating GSR and G6PD-targeted pathways involved in glutathione metabolism. These results provide valuable evidence for further investigating the mechanism of XHP in treating glioma. The animal welfare and experimental procedures were approved by the Ethical Committee of Laboratory Animals at Nanjing University of Chinese Medicine (approval No. ACU221001).

BACKGROUND:Fluorosis is a disorder of enamel development caused by long-term intake of large amounts of fluoride during enamel development. OBJECTIVE:To further explore the molecular mechanism of dental fluorosis formation by screening the differentially expressed genes associated with calcium homeostasis in ameloblasts by transcriptome sequencing technology. METHODS:LS8 cells were treated with 0,0.4,0.8,1.6,3.2 and 6.4 mmol/L sodium fluoride(NaF)for 24,48 and 72 hours to observe the effects of different concentrations of NaF on the morphology,cell activity and intracellular Ca2+ concentration of LS8 cells.The differentially expressed genes were screened by transcriptome sequencing and validated. RESULTS AND CONCLUSION:After 24 hours of treatment,the cells treated with 0,0.4,and 0.8 mmol/L NaF were in good growth condition,with increased cell number and clear cell outline.When the NaF concentration was≥1.6 mmol/L,the cells were gradually shrunken and became smaller and the number of cells decreased with the increase of NaF concentration.After 48 and 72 hours of treatment,the number of cells increased in the 0,0.4 mmol/L NaF groups,while gradually decreased in the 0.8,1.6,3.2 mmol/L NaF groups,with rounded and smaller cell morphology.The cells in the 6.4 mmol/L NaF group were shrunken,rounded and suspended in the medium,with almost no adherent cells.When treated with the same concentration of NaF,LS8 cells were in optimal growth after 24 hours of treatment.Results from cell counting kit-8 assay showed that when treated with the same concentration of NaF,the cell activity decreased with the increase of treatment time;when the treatment time was the same,the cell activity decreased with the increase of NaF concentration.After 24 hours of treatment,the intracellular Ca2+ concentration increased with the increase of NaF concentration.Transcriptome sequencing analysis identified genes involved in the regulation of cellular calcium homeostasis:Hsp90b1,Canx,Calr,and Hspa5 that were significantly upregulated(P＜0.05)and Cacna1a that was significantly downregulated(P＜0.05).To conclude,the inhibitory effect of NaF on LS8 cell proliferation may be related to the abnormal increase in intracellular Ca2+ concentration,and the mechanism may be caused by the upregulation of the expression of protein processing and synthesis pathways Hsp90b1,Canx,Calr,and Hspa5 and the downregulation of the expression of calcium signaling pathway Cacna1a.

BACKGROUND:In the construction of guided bone regeneration membrane with biological function,a single material cannot meet the clinical needs due to its insufficient function,so the composite of multiple materials has become a trend of tissue repair engineering. OBJECTIVE:To prepare silk fibroin/bioactive glass composite fiber membranes by electrospinning technology,and to characterize the physicochemical properties and biocompatibility in vitro. METHODS:The solution of electrospinning was prepared by dissolving 0.8 g silk fibroin protein in 10 mL hexafluoro-isopropanol alcohol,and the nanofiber membrane of silk fibroin protein was prepared by electrospinning technology(denoted as SF fiber membrane).0.1,0.3,0.5,and 0.8 g of bioactive glass were added to the electrospinning solution,and the silk fibroin/bioactive glass composite fiber membrane was prepared by electrospinning technology(recorded as SF/1BG,SF/3BG,SF/5BG,and SF/8BG fiber membrane in turn).The physicochemical properties and biocompatibility of five groups of fiber membranes were characterized. RESULTS AND CONCLUSION:(1)The scanning electron microscopy results showed that nanofibers of the prepared composite membrane were smooth,continuous and uniform and had no beaded structure.There was no obvious adhesion between the silk fibers,and they all showed random arrangement of disordered porous structures.The fiber diameter of the fiber membrane decreased after the addition of bioactive glass.Fourier infrared spectroscopy and X-ray diffraction detection results showed that the chemical structure of silk fibroin protein and bioactive glass in fiber membrane was stable.The water contact angles of SF,SF/1BG,SF/3BG,SF/5BG,and SF/8BG were 105.02°,72.58°,78.13°,79.35°,and 72.50°,respectively.(2)Bone marrow mesenchymal stem cells were inoculated on five groups of fiber membranes.CCK-8 assay results showed that SF/1BG,SF/3BG,and SF/5BG fiber membranes could promote the proliferation of bone marrow mesenchymal stem cells compared with SF and SF/8BG.Live cell/dead cell staining showed that the cell vitality on the surface of the five groups of fiber membranes was better,and the number and distribution of cells on the surface of SF/5BG fiber membrane were more uniform.Rhodamine phalloidin staining and scanning electron microscopy exhibited that compared with SF fiber membrane,the SF/5BG fiber membrane was more favorable to the adhesion of bone marrow mesenchymal stem cells.Bone marrow mesenchymal stem cells were inoculated on the fiber membrane of the five groups for osteogenic induction differentiation,and the alkaline phosphatase activity of the SF/3BG and SF/5BG groups was higher than that of the other three groups(P＜0.05,P＜0.01,P＜0.001).Alizarin red staining showed that the formation of calcium nodules in fiber membrane increased after the addition of bioactive glass,and the formation of calcium nodules in the SF/5BG group was the most.(3)The results show that silk fibroin/bioactive glass composite fiber membrane has good biosafety and biocompatibility.

BACKGROUND:Fluid shear stress plays an important role in osteoblast proliferation and apoptosis.However,whether Caveolin-1 is involved in the process of fluid shear stress-induced proliferation and apoptosis in osteoblasts is unknown. OBJECTIVE:To explore the role of Caveolin-1 in fluid shear stress-regulated osteoblast proliferation and apoptosis. METHODS:The MC3T3-E1 osteoblasts in good growth status were selected and loaded with fluid shear stress at an intensity of 1.2 Pa for different times(0,30,60,90 minutes).The expression of Caveolin-1 protein was observed and conditions with a time of 60 minutes were screened for the experiment.MC3T3-E1 cells were divided into control group,fluid shear stress group,fluid shear stress+pcDNA 3.1 group(control),fluid shear stress+pcDNA Cav-1 group(plasmid overexpression),and intervened with fluid shear stress and overexpression of Cav-1,respectively.The expression of molecules related to proliferation and apoptosis in MC3T3-E1 cells was detected by qRT-PCR and western blot.In addition,the proliferative activity of MC3T3-E1 cells was detected by cell counting kit-8 and EdU assay;and cell apoptosis was detected by Hoechst 33258 and flow cytometry. RESULTS AND CONCLUSION:The expression of Caveolin-1 in MC3T3-E1 cells was significantly down-regulated after loading fluid shear stress,and the expression level was lowest after 60 minutes.Overexpression of Caveolin-1 attenuated the proliferation-promoting and apoptosis-suppressing effects of fluid shear stress in MC3T3-E1 cells.In conclusion,Caveolin-1 has a vital role in fluid shear stress-regulated osteoblast proliferation and apoptosis,which may offer a potential therapeutic strategy for osteoporosis.

Objective We aimed to investigate the effects of Biejiajian Pills on MHCC-97H hepatoma cells and whether Biejiajian Pills regulate the epidermal growth factor receptor (EGFR)/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway through miR-885-5p.Methods SPF SD rats (n = 10) were randomly divided into the blank group and the Biejiajian Pills (1.1 g/kg) group to prepare blank and Biejiajian Pills-containing serum. MHCC-97H cells in the logarithmic growth phase were divided into the model group, blank serum groups with different concentrations (5％, 10％, 15％, and 20％), the serum containing Biejiajian Pills group, and the blank group without cells. Cell proliferation was detected by the CCK-8 assay, and the optimal intervention time and concentration of drug-containing serum were screened. MHCC-97H cells were divided into the blank control group (no intervention), the Biejiajian Pills-containing serum group (20％ Biejiajian Pills-containing serum), the miR-885-5p mimics group (transfected with miR-885-5p mimics), the miR-NC group (transfected with miR-885-5p NC), and the Biejiajian Pills-containing serum + miR-885-5p mimics group (treated with 20％ Biejiajian Pills-containing serum and transfected with miR-885-5p mimics). Cells in each group were cultured for 72 hours. A dual luciferase reporter assay was conducted to verify the targeting relationship between miR-885-5p and EGFR. Cell proliferation was detected by the CCK-8 assay, cell migration and invasion abilities were detected by the cell scratch assay and the Transwell invasion assay. Annexin V-APC/PI double staining was performed to detect the apoptosis level, and real-time fluorescence quantitative PCR (RT-qPCR) analysis was conducted to determine the mRNA expression levels of miR-885-5p, EGFR, MEK, and ERK1/2. The expression levels of EGFR, p-EGFR, MEK, p-MEK, ERK1/2, p-ERK1/2, matrix metalloproteinase 1 (MMP1), and CyclinD1 were determined by Western blotting analysis. The subcutaneous tumor model of MHCC-97H hepatoma cells in nude mice was established by subcutaneous injection to observe the inhibitory effect of Biejiajian Pills of different doses(0.55,1.1,2.2 g/kg).Results The optimal concentration and intervention time of Biejiajian Pills-containing serum were 20％ and 72 hours, respectively. Meanwhile, the dual luciferase reporter assay showed that miR-885-5p could directly target EGFR. No statistical significances between the blank control group and the miR-NC group were observed (P>0.05). Compared with the blank control group, the proliferation rates of MHCC-97H hepatoma cells in the Biejiajian Pills-containing serum group, the miR-885-5p mimics group, and the Biejiajian Pills-containing serum + miR-885-5p mimics group were significantly decreased (P<0.01), and their migration and invasion abilities were significantly decreased (P<0.05, P<0.01). At the same time, the protein expression levels of CyclinD1 and MMP1, which are closely related to cell proliferation and invasion, were significantly downregulated (P<0.05, P<0.01). The proportions of late apoptotic cells and the proportion of total apoptotic cells were significantly increased (P<0.01). In the Biejiajian Pills-containing serum group, the miR-885-5p mimics group, and the Biejiajian Pills-containing serum + miR-885-5p mimics group, miR-885-5p mRNA was significantly upregulated (P<0.01) and EGFR, MEK, and ERK1/2 were significantly downregulated at the mRNA level (P<0.05, P<0.01). EGFR, MEK, and ERK1/2 phosphorylation was inhibited (P<0.01), and the Biejiajian Pills-containing serum + miR-885-5p mimics group showed the best effect (P<0.05, P<0.01). The subcutaneous liver tumor model in nude mice verified that Biejiajian Pills can inhibit tumor growth in a dose-dependent manner. Conclusion Biejiajian Pills can promote apoptosis of MHCC-97H hepatoma cells and inhibit their proliferation, invasion, and migration. The mechanism may be related to the targeted regulation of the EGFR/MAPK/ERK signaling pathway by miR-885-5p.

Sonogenetics is an emerging synthetic biology technique that uses sound waves to activate mechanosensitive ion channel proteins on the cell surface to regulate cell behavior and function.Due to the widespread presence of mechanically sensitive ion channel systems in cells and the advantages of non-invasion,strong penetrability,high safety and high accuracy of sonogenetics technology,it has great development potential in basic biomedical research and clinical applications,especially in neuronal regulation,tumor mechanism research,sonodynamic therapy and hearing impairment.This review discusses the basic principles of sonogenetics,the development status of sonogenetics and its application in the prevention and treatment of noise-induced hearing loss,summarizes and analyzes the current challenges and future development direction,thus providing a reference for further research and development of sonogenetics in the field of military medicine.