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 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.

ObjectiveTo analyze the characteristics of HIV-1 molecular network and pretreatment drug resistance genes in the middle-aged and elderly people aged ≥50 years in Huzhou City, Zhejiang Province, and to provide an evidence for the prevention and control of AIDS epidemic. MethodsA total of 332 samples from the newly reported and untreated AIDS patients aged ≥50 years in Huzhou City from January 2020 to December 2023 were collected, pol genes were amplified by reverse transcription polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (nest⁃PCR). Phylogenetic trees analyzing the subtypes were constructed, and a molecular network with a gene distance threshold of 1.0% were constructed at the same time. Mutation sites of drug resistance-related genes were identified through the Data Analysis and Detection System of HIV-1 Resistance Gene Detection of Stanford University, USA. ResultsSequence samples of 308 patients were obtained, and9 genotypes were identified, including CRF07_BC in 172 cases (55.8%), CRF01_AE in 61 cases (19.8%), CRF08_BC in 43 cases (14.0%), CRF85_BC in 9 cases (2.9%), and CRF55_01B in 8 cases (2.6%), subtype B in 5 cases (1.6%), subtype C in 4 cases (1.3%), CRF67_01B in3 cases (1.0%), and unique recombination URF01_AE/07_BC in 3 cases (1.0%). When the gene distance threshold was 1.0%, 28 molecular clusters were formed, and 139 cases were connected to the network, with an access rate of 45.0%. The largest transmission cluster C1 contained 44 cases infected with CRF07_BC subtype, all of whom were heterosexually transmitted, and predominantly by males. A total of 30 patients were found to have low-grade or higher drug resistance mutations, and the pretreatment drug resistance rate was 9.7% (30/308). Among them, there were 5 cases (16.7%) of protease inhibitor (PI) related drug resistance mutations, and 26 cases (86.7%) of non-nucleoside reverse transcriptase inhibitors (NNRTI) related drug resistance mutations. ConclusionCRF07_BC is the subtype with the most clusters among the middle-aged and elderly infected patients aged ≥50 years in Huzhou City. Middle-aged and elderly transmission clusters are formed within the three counties of WX, NX and CX through related activities. Molecular network monitoring on newly reported cases aged ≥50 years in Huzhou City should be strengthened so that the new characteristics of epidemic changes can be detected in time, providing a scientific basis for adjusting AIDS prevention and control measures for the elderly.

Objective To investigate the value of single photon emission computed tomography/computed tomography(SPECT/CT)fusion imaging for post-implantation dose verification of 125I particles in patients with bone metastases.Methods Forty patients with metastatic bone tumors treated with 125I particles implantation were selected.Within 24 h after 125I particles implantation,patients underwent SPECT/CT fusion imaging and the radioactivity per unit(RPU)was calculated.The treatment planning system(TPS)was then used to obtain the isodose profiles of SPECT/CT fusion imaging results and to calculate the tumor target coverage.The patient's preoperative and postoperative 1 month clinical outcomes,including local tumour remission,pain assessment,quality of life and serum alkaline phosphatase(ALP)levels were compared,and a receiver operating characteristic(ROC)curve was applied to evaluate the predictive value of tumor target coverage on postoperative outcomes.Results The mean number of particles implanted in the target area was 32.52±12.87.Within 24 h of 125I particles implantation,SPECT/CT fusion imaging analysis confirmed a strong positive correlation between the RPU of the radioactive concentration area and the mean dose received by the patient(r=0.786,P<0.05).The predicted area under the curve(AUC)for local tumor remission,pain relief,quality of life improvement and change in ALP levels was 0.789,0.757,0.804 and 0.833,respectively.Conclusion SPECT/CT fusion imaging can be used for postoperative dose verification of 125I particles for metastatic bone tumors and has some predictive value for clinical outcomes.

Objective To investigate the predict value of imaging parameters in computed tomography perfusion(CTP)combined with computed tomography angiography(CTA)examination and serum biomarkers for recurrent stroke events at three-month and one-year follow-ups.Methods A total of 136 patients with cerebral infarction diagnosed for the first time were included in the retrospective study.These patients received CTA+CTP one-stop examination and serum biomarkers testing,followed by three-month and one-year follow-ups for the occurrence of recurrent stroke events.Recurrent stroke events were defined as ischemic stroke,retinal infarction,intracerebral hemorrhage,subarachnoid hemorrhage,and death.Results The recurrent stroke events rate was 23.5%(32 cases)and 36.8%(50 cases)at three-month and one-year follow-ups,respectively.Ischemic penumbra(IP)volume[odds ratio(OR)=1.010,P=0.029]and modified Rankin scale(mRS)score at discharge(OR=1.388,P=0.008)were independent predictors for recurrent stroke events at the three-month follow-up,so were lipoprotein(a)[Lp(a)](OR=1.002,P=0.044),vascular stenosis severity(OR=1.489,P=0.029),and mRS score at discharge(OR=1.282,P=0.038)at the one-year follow-up.Conclusion Among patients with stroke diagnosed for the first time,IP volume,Lp(a),vascular stenosis severity and mRS score at discharge are the most powerful predictors of recurrent stroke events at three-month and one-year follow-ups.