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.

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.

Objective To evaluation the bioequivalence of telmisartan tablets(80 mg)between test formulation and reference formulation in Chinese healthy subjects.Methods A single-center,randomized,open-label,two-preparations,single administration,partial repeat crossover of three sequences in three postprandial cycles and complete repeat crossover of two sequences in four fasting cycles,bioequivalence test was designed.Chinese healthy subjects were included in the bioequivalence trial,with 33 randomly assigned to the postprandial group and 32 randomly assigned to the fasting group.In each period,blood samples was collected before and after administration.The plasma concentration of the drug was determined by LC-MS/MS,using WinNonlin version 8.3 calculate the pharmacokinetic parameters and perform a statistical analysis using SAS version 9.4.Results The main pharmacokinetic parameters of telmisartan tablets after oral administration of test or reference were as follows.Fasting group Cmax were(556.10±456.06)and(580.99±533.50)ng·mL-1;AUC0-t were(3 475.15±3 785.16)and(3 450.54±3 681.02)ng·mL-1·h;AUC0-∞ were(3 214.06±2 272.06)and(3 194.84±2 187.45)ng·mL-1·h.The 90％confidence intervals of the geometric mean ratio of Cmax,AUC0-t,AUC0-∞ were within the requirements of the equivalent range of bioequivalence(80.00％-125.00％).Postprandial group Cmax were(299.26±124.72)and(291.29±126.34)ng·mL-1;AUC0-t were(3 682.24±2 799.72)and(3 636.71±2 158.42)ng·mL-1·h;AUC0-were(3 544.53±1 553.06)and(3 969.38±2 528.22)ng·mL-1·h.The 90％confidence intervals of the geometric mean ratio of Cmax,AUC0-t,AUC0-∞ were within the requirements of the equivalent range of bioequivalence(80.00％-125.00％).Conclusion Under fasting and fed conditions,two kinds of telmisartan tablets are bioequivalent in Chinese healthy subjects.

Objective This study aimed to investigate the effects of high-altitude hypoxia on the expression of ATP-binding cassette(ABC)transport proteins in the blood-brain barrier(BBB)and explore the mechanisms influencing their expression.Methods Wistar rats were divided into 1500 m group(Lanzhou field),4010 m group(simulated 4010 m,low-pressure oxygen chamber,hypoxia for 3 days),6000 m group(simulated 6000 m,low-pressure oxygen chamber,hypoxia for 3 days),phenytoin sodium+1500 m group(given 50 mg·kg-1 phenytoin sodium on the basis of the 1500 m group),phenytoin sodium+4010 m group(given 50 mg·kg-1 phenytoin sodium on the basis of the 4010 m group),phenytoin sodium+6000 m group(given 50 mg·kg-1 phenytoin sodium on the basis of the 6000 m group),and hypoxia 1 d group,hypoxia 2 d group,hypoxia 3 d group,hypoxia 4 d group(simulated altitude of 4010 m,low-oxygen chamber,hypoxia for 1,2,3,4 days).Western blot was used to detect the expression of BBB tissue proteins;and liquid chromatography-tandem mass spectrometry was used to measure the concentration of phenytoin sodium in cerebrospinal fluid.Results The relative expression levels of P-glycoprotein(P-gp)in the 1500 m,4010 m,6000 m groups were 1.00±0.04,1.84±0.02,2.10±0.05,respectively;the relative expression levels of multidrug resistance-associated protein-4(MRP4)were 1.00±0.05,2.77±0.08,4.42±0.03,respectively;the concentrations of phenytoin sodium in cerebrospinal fluid were(864.78±348.32),(1 000.22±273.90),and(1 214.17±314.09)ng·mL-1,respectively.The differences in the above indicators between the 1500 m,4010 m,and 6000 m groups were statistically significant(all P＜0.05).The relative expression levels of P-gp in the hypoxia 1 d,2 d,3 d,4 d groups were 1.00±0.03,1.85±0.04,3.10±0.02,2.17±0.05,respectively;the relative expression levels of MRP4 were 1.00±0.05,1.79±0.10,1.60±0.08,1.31±0.06,respectively;the differences in the above indicators between the hypoxia 1 d,2 d,3 d,4 d groups were statistically significant(all P＜0.05).Conclusion Different high-altitude hypoxic environments have different effects on the expression of ABC transport proteins in the BBB,influencing the drug concentrations of their substrate drugs in the body.

Objective To explore the effect of rifampicin on the pharmacokinetics of linezolid in mice and provide pharmacokinetic evidence for the formulation of safe drugs for clinical use of pulmonary tuberculosis.Methods Fifty male KM mice were randomly divided into 2 groups:Control group,rifampicin group;the control group was given 15 mg·kg-1 linezolid;the rifampicin group was given 100 mg·mL-1 rifampicin,continuous administration for 7 days,followed by gavage,administration of 15 mg·kg-1 linezolid;blood and lung tissue were collected from mouse at different time points after administration.High performance liquid mass spectrometry(LC-MS/MS)was used to determine plasma concentration of linezolid and compared the pharmacokinetics between groups.Pharmacokinetic parameters were calculated using DAS 2.0 software.Results Main pharmacokinetic parameters of plasma linezolid in control group,rifampicin group were as follows:AUC0_t were(23.88±1.16)and(19.06±2.56)pg·mL-1·h,respectively;t1/2 were((1.15±0.11)and(1.11±0.10)h,respectively;Cmax were(9.93±0.46)and(7.74±1.17)μg·mL-1,respectively.The main pharmacokinetic parameters of the lungs in the control group and the rifampicin group were as follows:AUC0_t were(18.76±4.29)and(14.90±1.52)μg·mL-1·h,respectively;t1/2 were(1.94±0.50)and(1.44±0.07)h,respectively;Cmax were(8.28±2.67)and(6.82±1.57)μg·mL-1,respectively.AUC0_t and Cmax in plasma and AUC0_t in lung tissue of control group were significantly different from those of rifampicin group(all P＜0.05).Conclusion After the combination of rifampicin,linezolid plasma and lung tissue exposure decreased significantly,and attention should be paid to monitoring linezolid trough concentration when the two drugs were combined to avoid treatment failure caused by low effective concentration.

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.

ObjectiveAlveolar macrophages (AMs) are critical for maintaining the homeostasis of pulmonary microenvironment. They process surfactants to ensure alveoli patency, and also serve as the first line of immune defense against pathogen invasion. Available studies have shown that monocyte-derived AMs continuously release pro-inflammatory cytokines and chemokines, recruiting other immune cells to the damaged area during pulmonary fibrosis. These monocyte-derived AMs maintains and amplifies inflammation, playing a negative role in pulmonary fibrosis progression. Current researches have predominantly focused on the gene expression levels of AMs in pulmonary fibrosis microenvironment, with less emphasis on the function and regulation of proteins. This study aims to investigate the differentially expressed proteins (DEPs) of AMs under normal physiological conditions and after pulmonary fibrosis, in order to gain a more comprehensive understanding of the role of AMs in the progression of pulmonary fibrosis. MethodsFirstly, the construction of bleomycin-induced pulmonary fibrosis mouse models was evaluated through using measurements such as body mass, lung coefficient, lungwet-to-dry mass ratio, H&E staining and Masson staining. Subsequently, AMs from both the saline controls and the pulmonary fibrosis models (2.5×10⁵ cells per sample) were collected using FACS sorting, and protein expression profiles of these cells were obtained through label-free proteomics approach. The quality of the proteomic data was assessed by comparing our saline control proteomic data with public proteomic data of physiological AMs. Thirdly, DEPs analysis between the saline controls and the bleomycin groups was carried out using R package Prostar. Functional enrichment analyses of significantly upregulated DEPs were performed using R package Clusterprofiler for GO and KEGG pathways. Finally, the STRING database was used to explore the protein-protein interaction networks related to phagocytosis regulation, inflammatory response regulation, andI-κB/NF-κB signaling pathway. The expression levels of Tlr2 and Pycard were detected respectively by FACS and western blotting. ResultsCompared to the saline controls, mice in the bleomycin groups exhibited a lower average body mass, extensive infiltration of inflammatory cells, and deposition of collagen in the lungs. This indicates that bleomycin successfully induced pulmonary fibrosis in mouse models. The proteomic data of AMs obtained from these models was of high quality and fulfilled the research requirements. A comprehensive analysis showed that 778 proteins were upregulated in pulmonary fibrosis groups compared with control groups. Moreover, the signal pathways enriched in up-regulated DEPs were related to the I‑κB/NF‑κB pathway, inflammatory response regulation, phagocytosis regulation, TGF-β signaling, and HIF-1 pathway, indicating that AMs in pulmonary fibrosis microenvironment exerted pro-inflammatory and pro-fibrotic functions. Protein-protein interaction network analysis of the DEPs suggested that the interactions between Tlr2 and Pycard were control nodes for the pro-inflammatory phenotype of AMs, thereby contributing to pulmonary fibrosis progression. Further validation by FACS and Western blotting respectively confirmed that the expression levels of Tlr2 and Pycard in AMs were significantly increased after pulmonary fibrosis. ConclusionThis study investigates the changes in the protein expression profile of AMs in the pulmonary fibrosis microenvironment. The results show that AMs notably enhanced the activity of various pathways associated with inflammation and fibrosis, suggesting that the interaction between Tlr2 and Pycard serves as a key control node for the highly pro-inflammatory behavior of AMs.

A novel series of 2-aryl substituted benzothiopyranone compounds was designed and synthesized based on our previously obtained benzothiopyranone scaffold with significant antituberculosis activity. All target compounds were evaluated for their antimycobacterial activity and preliminary druggability was subsequently investigated for some selected compounds with good activity. The results indicated that most compounds showed good activity against Mycobacterium tuberculosis H₃₇Rv. Among them, compounds 8g, 8h, 8q and 9f showed potent activity with MIC ranged from 0.2 to 0.4 μg·mL^-1. Furthermore, some active compounds exhibited low cytotoxicity and cardiotoxicity risk. It is worth noting that compounds 8h and 8q with good liver microsome stability and low inhibition of CYPs 3A4/5 and 2C9 were suitable for combination drug regimen to treat tuberculosis.

italic>Salvia miltiorrhiza, a commonly used traditional Chinese medicine, has been widely recognized for its blood-activating and stasis-removing properties in the clinical treatment of cardiovascular and cerebrovascular diseases. The synthesis and regulatory mechanism of tanshinones, the key active constituents of Salvia miltiorrhiza, have been a hot topic of research. The paper summarized the research findings on the regulation of tanshinone biosynthesis by transcription factors such as AP2/ERF, bHLH, MYB, bZIP, and WRKY in recent years. The review identifies the existing issues in the transcriptional regulation studies of Salvia miltiorrhiza and discusses the research direction of transcription factors in the regulation of tanshinone biosynthesis, providing a theoretical basis for the further discovery and utilization of functional genes involved in the regulation of tanshinone bioactive constituents.