Antibiotic adjuvants offer a promising strategy for restoring antibiotic sensitivity, expanding antibacterial spectra, and reducing required dosages. Previously, compound 15 was identified as a potential adjuvant for Polymyxin B (PB) against multidrug-resistant (MDR) Pseudomonas aeruginosa DK2; however, its clinical utility was hindered by high cytotoxicity, uncertain in vivo efficacy, and an unclear synergetic mechanism. To address these challenges, we synthesized and evaluated a series of novel benzamide derivatives, with A22 emerging as a particularly promising candidate. A22 demonstrated potent synergistic activity to PB, minimal cytotoxicity, improved water solubility, and broad-spectrum synergism of polymyxins against various clinically isolated MDR Gram-negative strains. In vivo studies using Caenorhabditis elegans and mouse models further confirmed the efficacy of A22. Moreover, A22 effectively suppressed the development of PB resistance in Pseudomonas aeruginosa DK2. Mechanistic investigations revealed that A22 enhances polymyxins activity by inducing reactive oxygen species production, reducing ATP levels, increasing NOX activity, and inhibiting biofilm formation, leading to bacterial death. These findings position A22 as a highly promising candidate for the development of polymyxin adjuvants, offering a robust approach to combating MDR Gram-negative bacterial infections.

OBJECTIVES: To investigate the effects of quercetin on cuproptosis and L-type calcium currents in the myocardium of diabetic rats. METHODS: Forty SD rats were randomized into control group and diabetic model groups. The rat models of diabetes mellitus (DM) induced by high-fat and high-sugar diet combined with streptozotocin (STZ) injection were further divided into DM model group, quercetin treatment group, and empagliflozin treatment group (n=10). Blood glucose and body weight were measured every other week, and cardiac function of the rats was evaluated using echocardiography. HE staining, Sirius red staining, and wheat germ agglutinin (WGA) analysis were used to observe the changes in myocardial histomorphology, and serum copper levels and myocardial FDX1 expression were detected. In cultured rat cardiomyocyte H9c2 cells with high-glucose exposure, the effects of quercetin and elesclomol, alone or in combination, on intracellular CK-MB and LDH levels and FDX1 expression were assessed, and the changes in L-type calcium currents were analyzed using patch-clamp technique. RESULTS: The diabetic rats exhibited elevated blood glucose, reduced body weight, impaired left ventricular function, increased serum copper levels and myocardial FDX1 expression, decreased L-type calcium currents, and prolonged action potential duration. Quercetin and empagliflozin treatment significantly lowered blood glucose, improved body weight, and restored cardiac function of the diabetic rats, and compared with empagliflozin, quercetin more effectively reduced serum copper levels, downregulated FDX1 expression, and enhanced myocardial L-type calcium currents in diabetic rats. In H9c2 cells, high glucose exposure significantly increased myocardial expressions of FDX1, CK-MB and LDH, which were effectively lowered by quercetin treatment; Elesclomol further elevated FDX1, CK-MB and LDH levels in the exposed cells, and these changes were not significantly affected by the application of quercetin. CONCLUSIONS Quercetin ameliorates myocardial injury in diabetic rats possibly by suppressing myocardial cuproptosis signaling and restoring L-type calcium channel activity.
Animals ; Quercetin/pharmacology* ; Calcium Channels, L-Type/metabolism* ; Diabetes Mellitus, Experimental/metabolism* ; Rats, Sprague-Dawley ; Rats ; Myocytes, Cardiac/drug effects* ; Myocardium/pathology* ; Male

Given the increasing concern regarding antibacterial resistance, the antimicrobial properties of naphthoquinones have recently attracted significant attention. While 1,4-naphthoquinone and its derivatives have been extensively studied, the antibacterial properties of 5,8-dihydroxy-1,4-naphthoquinone derivatives remain relatively unexplored. This study presents a comprehensive in vitro and in vivo analysis of the antibacterial activity of 35 naturally sourced and chemically synthesized derivatives of 5,8-dihydroxy-1,4-naphthoquinone. Kirby-Bauer antibiotic testing identified three compounds with activity against methicillin-resistant Staphylococcus aureus (MRSA), with one compound (PNP-02) demonstrating activity comparable to vancomycin in minimum inhibitory concentration, minimum bactericidal concentration (MBC), and time-kill assays. Microscopic and biochemical analyses revealed that PNP-02 adversely affects the cell wall and cell membrane of MRSA. Mechanistic investigations, including proteomic sequencing analyses, Western blotting, and RT-qPCR assays, indicated that PNP-02 compromises cell membrane integrity by inhibiting arginine biosynthesis and pyrimidine metabolism pathways, thereby increasing membrane permeability and inducing bacterial death. In an in vivo mouse model of skin wound healing, PNP-02 exhibited antibacterial efficacy similar to vancomycin. The compound demonstrated low toxicity to cultured human cells and in hemolysis assays and remained stable during serum incubation. These findings suggest that PNP-02 possesses promising bioactivity against MRSA and represents a potential novel antibacterial agent.
Methicillin-Resistant Staphylococcus aureus/genetics* ; Anti-Bacterial Agents/chemistry* ; Naphthoquinones/administration & dosage* ; Animals ; Microbial Sensitivity Tests ; Mice ; Humans ; Staphylococcal Infections/microbiology* ; Molecular Structure

Objective To investigate the role of circular RNAs(circRNA)in Alzheimer's disease(AD)and its potential mechanism.Methods Six-month-old APP/PS1 mouse model of AD and wild type(WT)mice were subjected and then randomly divided into WT group,WT+circ-Olfm1 knockout group,AD group(transgenic APP/PS1 mice),AD+circ-Olfm1 knockout group,AD+FOXO3a knockout group,with 3 mice in each group.① The total RNA of mouse brain was extracted,and the differential expression of circRNAs and mRNAs between the AD mice and WT mice was detected,and the obtained circRNAs and mRNAs were analyzed with gene ontology(GO)analysis.② RT-qPCR was used to detect the expression of the top 10 up-regulated and down-regulated circRNAs,as well as the expression of circ-Olfm1 and miR-330-5p.③ Lentiviral vectors were prepared and stereotaxically injected into the cortex or hippocampus of WT and AD mice to knock out circ-Olfm1 gene.Water maze test was used to evaluate the effect of circ-Olfm1 knockout on cognitive function,and immunofluorescence assay was employed to observe the deposition of amyloid β(Aβ)plaque in the brain.④ The interaction between circ-Olfm1 and miR-330-5p was verified by double luciferase reporter gene analysis.⑤ The protein levels of AMPK and FOXO3a were detected by Western blotting.⑥ Transmission electron microscopy was utilized to observe the mitochondria of the hippocampus.⑦ The levels of inflammatory factors IL-6,IL-1β and TNF-α were detected by ELISA.Results There were totally 52 differentially expressed circRNAs identified between the AD and WT mice,including 28 up-regulated and 24 down-regulated(fold change>1.5,P<0.05).These differentially expressed genes are mainly involved in signal transduction,learning and memory and other functions.circ-Olfm1 was identified as the most significantly differentially expressed circRNA,which is highly expressed in the neurons and up-regulated in the cerebral cortex and hippocampus of the AD mice.Knockout of circ-Olfm1 reduced the number of Aβ plaques in the cerebral cortex and hippocampus of AD mice(P<0.01).In starBase database,there are complementary sequences observed between circ-Olfm1 and miR-330-5p.Western blotting showed that the addition of Aβ42 significantly increased the expression of AMPK and FOXO3a in the neuronal cells(P<0.01).And silencing circ-Olfm1 led to decreased expression of AMPK and FOXO3a in neuronal cells+Aβ42(P<0.01).ELISA revealed that knockout of FOXO3a significantly increased the levels of inflammatory factors IL-6,IL-1β,and TNF-α(P<0.01).Transmission electron microscopy displayed that knocking FOXO3a out significantly aggravated mitochondrial damage(P<0.01).Conclusion circ-Olfm1 is up-regulated in the brain tissue and neurons+Aβ42 of AD rats,and the mechanism of cognitive impairment in AD rats may be through its regulating FOXO3a protein.

Objective To investigate the effect of pramlintide,a pancreatic amyloid peptide analog,on learning and memory of Alzheimer's disease(AD)mice through antioxidant stress,and to determine the expression of phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway.Methods The APP/PS1 mice were divided into a pramlintide treatment group(intraperitoneal injection of 0.5 μmol/L per day for 10 weeks)and an AD group(same dose of PBS),with 5 mice in each group.The learning and memory abilities were detected with water maze test,the pathological changes of the hippocampus were observed with HE staining and immunohistochemistry,the morphological characteristics of dendritic spines in hippocampus were observed after Golgi staining,and the ultrastructure of hippocampal neurons was observed through transmission electron microscopy(TEM).The content of malondialdehyde(MDA)and the level of superoxide dismutase(SOD)in the hippocampal tissue were detected by biochemical assay,and the levels of inflammatory factors IL-6,TNF-α and IL-1β were determined with ELISA.Western blotting was applied to measure the expression of PI3K/Akt signaling pathway related proteins in the hippocampus.In the cell experiment,SH-SY5Y cells were added with Aβ 1-42 to establish a cell model of AD.After the cells were treated with pramlintide,the levels of oxidative stress and inflammatory response were detected,and cell apoptosis was detected by immunofluorescence.Results The animal experiments showed that pramlintide treatment resulted in significantly shortened escape latency(P<0.01),increased platform crossings(P<0.01),and prolonged time to exploring hidden platform(P<0.01).In the hippocampal tissue of the pramlintide treatment group,HE staining displayed hippocampal neurons in high density and neat arrangement(P<0.05),immunohistochemical results showed significantly reduced Aβ protein(P<0.01),Golgi staining results demonstrated more dendritic spines(P<0.05),TEM revealed almost intact neuronal mitochondrial structure,with reduced vacuolization and clear and identifiable morphology.When compared with the AD group,the levels of oxidative stress and inflammatory response were decreased(P<0.01),and the relative expression of p-PI3K/PI3K and p-Akt/Akt proteins was increased(P<0.01)in the treatment group.In cell experiments,the levels of oxidative stress and inflammatory response were decreased in AD cell model after pramlintide treatment(P<0.01),and the results of immunofluorescence showed that cell apoptosis was declined(P<0.01).Conclusion Pramlintide can improve the cognitive function,reduce the hippocampal deposition of Aβ,reduce oxidative stress and inflammatory response,alleviate the pathological changes of neuronal ultrastructure,and enhance the expression of PI3K/Akt signaling pathway in AD mice.

Objective To investigate the expression level of circular RNA circ-Tns3 in Alzheimer's disease(AD)mice and its role in Aβ-induced neuronal damage.Methods Five APP/PS1 transgenic AD mice and 5 wild-type(WT)mice,weighting of 23～26 g and aged 6 months were subjected in the study.Morris water maze test was used to assess learning and memory abilities,and immunohistochemical staining was performed to observe the number of Aβ plaques in the hippocampal tissue.Subsequently,total RNA was extracted from the brains to detect the differential expression of circRNAs between AD and WT mice,and the results were further analyzed with Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis.The top 6 differentially expressed circRNAs were validated by real-time quantitative PCR(RT-qPCR).In in vitro experiments,Aβ1-42 was used to treat neuronal cells to establish AD cell model,and si-circ-Tns3 was transfected into Aβ1-42-treated neuronal cells to knock down circ-Tns3.RT-qPCR was used to determine the expression levels of circ-Tns3 and miR-671-5p.Cell viability and apoptotic rate were detected by CCK-8 assay and TUNEL staining,respectively.The levels of superoxide dismutase(SOD)and malondialdehyde(MDA)were measured using corresponding kits,and the levels of inflammatory factors IL-6,IL-1β,and TNF-α were detected with ELISA.The interaction between circ-Tns3 and miR-671-5p was verified by dual-luciferase reporter assay and RNA-binding protein immunoprecipitation(RIP)assay.The expression level of Sirt1 protein was detected by Western blotting.Results The 6-month-old AD mice exhibited significant cognitive impairment and Aβ deposition(P<0.01).There were 269 differentially expressed circRNAs identified between AD and WT mice,of which 159 were up-regulated and 110 down-regulated.GO and KEGG enrichment analyses showed that these differentially expressed circRNAs were mainly involved in synaptic transmission,memory,and cholinergic synapse signaling pathways.The expression of circ-Tns3 was significantly increased not only in the brain tissue of AD mice but also in neuronal cells after Aβ1-42 treatment.In cellular experiments,knockdown of circ-Tns3 significantly reduced cell viability and number of apoptotic cells in Aβ1-42-treated neuronal cells,decreased MDA content,increased SOD activity,and reduced the levels of IL-6,IL-1β,and TNF-α(P<0.01).The starBase database predicted that circ-Tns3 and miR-671-5p have complementary sequences,and dual-luciferase reporter and RIP assays confirmed their interaction.The bioinformatics database predicted that miR-671-5p and sirt1 have complementary sequences.Western blotting indicated that in neuronal cells treated with Aβ1-42,the expression of sirt1 was increased after knockdown of circ-Tns3(P<0.01).In Aβ1-42-treated neuronal cells,after knockdown of circ-Tns3,addition of miR-671-5p inhibitor significantly decreased the expression level of sirt1 protein(P<0.01).Conclusions circ-Tns3 is highly expressed in AD mice and cell model of AD.Knocking circ-Tns3 down improves neuronal damage.circ-Tns3 may be involved in the neuronal damage through regulating sirt 1 protein by binding to miR-671-5p.

Objective To explore the phenotypic conversion of regulatory T cells (Tregs) in the lungs of mice with bronchopulmonary dysplasia (BPD)-affected mice. Methods A total of 20 newborn C57BL/6 mice were divided into air group and hyperoxia group, with 10 mice in each group. The BPD model was established by exposing the newborn mice to hyperoxia. Lung tissues from five mice in each group were collected on postnatal days 7 and 14, respectively. Histopathological changes of the lung tissues was detected by HE staining. The expression level of surfactant protein C (SP-C) in the lung tissues was examined by Western blot analysis. Flow cytometry was performed to assess the proportion of FOXP3⁺ Tregs and RORγt⁺FOXP3⁺ Tregs in CD4⁺ lymphocytes. The concentrations of interleukin-17A (IL-17A) and IL-6 in lung homogenate were measured by using ELISA. Spearman correlation analysis was used to analyze the correlation between FOXP3⁺Treg and the expression of SP-C and the correlation between RORγt⁺FOXP3⁺ Tregs and the content of IL-17A and IL-6. Results The hyperoxia group exhibited significantly decreased levels of SP-C and radical alveolar counts in comparison to the control group. The proportion of FOXP3⁺Tregs was reduced and that of RORγt⁺FOXP3⁺Tregs was increased. IL-17A and IL-6 concentrations were significantly increased. SP-C was positively correlated with the expression level of RORγt⁺FOXP3⁺ Tregs. RORγt⁺FOXP3⁺ Tregs and IL-17A and IL-6 concentrations were also positively correlated. Conclusion The number of FOXP3⁺ Tregs in lung tissue of BPD mice is decreased and converted to RORγt⁺ FOXP3⁺ Tregs, which may be involved in hyperoxy-induced lung injury.
Animals ; Mice ; Mice, Inbred C57BL ; Bronchopulmonary Dysplasia ; T-Lymphocytes, Regulatory ; Interleukin-17 ; Nuclear Receptor Subfamily 1, Group F, Member 3 ; Hyperoxia ; Interleukin-6 ; Forkhead Transcription Factors ; Lung

BACKGROUND:Pulmonary pericytes are located at the concavity where pulmonary vessels are interconnected,which is closely related to the formation and stability of pulmonary vascularization.However,there are few studies on how pulmonary pericytes affect the activity of pulmonary vascular endothelial cells in the pathogenesis of broncho-pulmonary dysplasia. OBJECTIVE:To analyze the relationship between the quantity of subgroups of pulmonary pericytes and endothelial cells in different stages of broncho-pulmonary dysplasia and to explore the effects of PDGFR-β+NG2+α-SMA+ pericytes on the early tube-forming activity of pulmonary vascular endothelial cells. METHODS:(1)Animal experiment:Twelve newborn C57BL/6 mice were randomly divided into normoxia and hyperoxia groups within 24 hours of birth,with six mice in each group.Mice in the hyperoxia group were exposed to an 85%O2 environment to build the mouse models of broncho-pulmonary dysplasia,while those in the normoxia group were fed in the same room air.The lung tissues of the mice in the two groups were taken at 7 and 14 days after birth.The pathological changes of the lung tissues were observed by hematoxylin-eosin staining.Three subgroups of pulmonary pericytes were measured by flow cytometry:PDGFR-β+NG2+α-SMA-,PDGFR-β+NG2+α-SMA+,and PDGFR-β+NG2-α-SMA+ cells.(2)Cellular experiment:Passage 3 PDGFR-β+NG2+α-SMA+ pericytes were co-cultured with mouse pulmonary vascular endothelial cells(experimental group)at a ratio of 1:4.Mouse pulmonary vascular endothelial cells cultured alone were used as controls.The tube-forming difference between two groups was analyzed after 15 hours of co-culture. RESULT AND CONCLUSION:(1)Animal experiment:Hematoxylin-eosin staining revealed that on day 7,the lung tissue of mice in the normoxia group had regular structure,obvious alveolar structure,and uniform size,while the number of alveoli in the lung tissue of mice in the hyperoxia group was less and the morphology of alveoli was irregular.On day 14,the alveoli of mice in the normoxia group gradually developed and matured,the alveolar structure gradually became regular and uniform in size,and the alveolar density gradually increased.The lung tissue structure of mice in the hyperoxia group was relatively disordered and the alveolar formation was delayed with the size gradually increasing and the alveolar structure being simplified.Flow cytometry results indicated that the number of PDGFR-β+NG2-α-SMA+ and PDGFR-β+NG2+α-SMA+ pericytes was increased in the hypoxia group compared with the normoxia group(P＜0.01),while the number of PDGFR-β+NG2+α-SMA-pericytes and pulmonary vascular endothelial cells was decreased(P＜0.01,P＜0.04).(2)Cellular experiment:In the control group,the pulmonary vascular endothelial cells arranged in cords and extended around,and lumen-like structures formed in some areas.In the experimental group,PDGFR-β+NG2+α-SMA+ pericytes and their pseudopodia were not observed,the irregular grid structure of pulmonary vascular endothelial cells was significantly less than that of the control group,and the endothelial cells mainly clustered in clumps.To conclude,α-SMA+ pericyte subgroups are predominant in mice with broncho-pulmonary dysplasia.PDGFR-β+NG2+α-SMA+ pericytes can directly inhibit the tube-forming activity of pulmonary vascular endothelial cells,which may be involved in the process of abnormal vascularization in broncho-pulmonary dysplasia.

Objective To investigate the effect of asiaticoside on blood pressure and relaxation of thoracic aorta in rats and explore the underlying mechanism.Methods SD rats treated with 50 and 100 mg/kg asiaticoside by daily gavage for 2 weeks were monitored for systolic blood pressure changes,and histological changes of the thoracic aorta were evaluated using HE staining.In isolated rat endothelium-intact and endothelium-denuded thoracic aorta rings,the effects of asiaticoside on relaxation of the aortic rings were tested at baseline and following norepinephrine(NE)-and KCl-induced constriction.The vascular relaxation effect of asiaticoside was further observed in NE-stimulated endothelium-intact rat aortic rings pretreated with L-nitroarginine methyl ester,indomethacin,zinc protoporphyrin Ⅸ,tetraethyl ammonium chloride,glibenclamide,barium chloride,Iberiotoxin,4-aminopyridine,or TASK-1-IN-1.The aortic rings were treated with KCl and NE followed by increasing concentrations of CaCl2 to investigate the effect of asiaticoside on vasoconstriction induced by external calcium influx and internal calcium release.Results Asiaticoside at 50 and 100 mg/kg significantly lowered systolic blood pressure in rats without affecting the thoracic aorta histomorphology.While not obviously affecting resting aortic rings with intact endothelium,asiaticoside at 100 mg/kg induced significant relaxation of the rings constricted by KCl and NE,but its effects differed between endothelium-intact and endothelium-denuded rings.In endothelium-intact aortic rings pretreated with indomethacin,ZnPP Ⅸ,barium chloride,glyburide,TASK-1-IN-1 and 4-aminopyridine,asiaticoside did not produce significant effect on NE-induced vasoconstriction,and tetraethylammonium,Iberiotoxin and L-nitroarginine methyl ester all inhibited the relaxation effect of asiaticoside.In KCl-and NE-treated rings,asiaticoside obviously inhibited CaCl2-induced vascular contraction.Conclusion Asiaticoside induces thoracic aorta relaxation by mediating high-conductance calcium-activated potassium channel opening,promoting nitric oxide release from endothelial cells and regulating Ca2+ influx and outflow,thereby reducing systolic blood pressure in rats.

Objective This study aimed to observe the outcomes of iRoot BP Plus full pulpotomy in primary molars with partial irreversible pulpitis retrospectively.Methods Collect 102 cases of primary molars with partial irreversible pulpitis undergoing iRoot BP Plus full pulpotomy from January 2019 to August 2023,with a follow-up period of 24-47 months.Based on the presence of irreversible pulpitis symptoms before surgery,the included cases will be divided into asymptomatic group(n=53)and symptomatic group(n=49).Observe the clinical and imaging success rates of both groups.Results Clinical success rates were 96.2%and 97.9%in asymptomatic and symptomatic groups,and ra-diographic success rates were 96.2%and 93.9%respec-tively.Conclusion iRoot BP Plus full pulpotomy can be used for the treatment of primary molars with partial irreversible pulpitis under an enhanced pulpotomy protocol.