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.

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 regulatory role of ubiquitin-specific protease 10(USP10)on the protein expression of Krüppel-like factor 4(KLF4)and its impact on the proliferation and invasion ability of hepatocellular carcinoma(HCC)cells.Methods The protein expression differences of USP10 and KLF4 in normal liver cell line L02 and HCC cell lines,including HepG2,HUH7,HCCLM3 were detected by immunoblotting(Western blot)methods.HCCLM3 and HUH7 cells were selected,and lentiviral particles overexpressing or silencing USP10(oe-USP10 or sh-USP10)was transfected into the cells,and they were designated as the oe-USP10 group and oe-NC group,respectively.Immunoprecipitation(Co-IP)experiments were conducted to examine whether USP10 could di-rectly interact with KLF4 in HCCLM3 or HUH7 cells.The Co-IP assay was repeated in HCC cells transfected with oe-USP10 or sh-USP10,with the addition of the proteasome inhibitor MG132,which used to detect the ubiquitina-tion level of KLF4 protein in the transfected HCC cells.The pcDNA3.1 vector containing overexpressed KLF4 or its negative control plasmid(pc-KLF4 or pc-NC)was co-transfected into cells of the sh-USP10 group or sh-NC group.These cells were designated as the sh-NC+pc-NC group,sh-USP10+pc-NC group,sh-NC+pc-KLF4 group,and sh-USP10+pc-KLF4 group.The cell proliferation activity of each group was measured using the CCK-8 assay,and the cell invasion ability was assessed using the Transwell assay.Results Compared to L02 cells,the protein expres-sion of USP10 and KLF4 significantly decreased in HepG2,HUH7,HCCLM3,and other cells(P＜0.05).In HC-CLM3 and HUH7 cells,USP10 protein directly interacted with KLF4.Furthermore,treatment with MG132 resulted in a time-dependent increase in KLF4 protein expression in HCCLM3 and HUH7 cells.Silencing USP10 increased the ubiquitination of KLF4 in HCCLM3 or HUH7 cells,while overexpressing USP10 decreased the ubiquitination level of KLF4 in cells.Compared to the sh-NC+pc-NC group,both the proliferation activity and invasion ability of HCCLM3 and HUH7 cells significantly increased in the sh-USP10+pc-NC group(P＜0.01),while they signifi-cantly decreased in the sh-NC+pc-KLF4 group and sh-USP10+pc-KLF4 group(P＜0.05).Compared to the sh-USP10+pc-NC group,the proliferation activity and invasion ability of cells significantly decreased in the sh-USP10+pc-KLF4 group(P＜0.05).Conclusion USP10 can promote the stability of KLF4 protein through deubiquiti-nation in HCC cell lines,thereby inhibiting the proliferation and invasion of tumor cells.

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 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

The annexins(ANX)family is widely present in the cell membrane,cytoplasm or extracellular matrix.As key tumor regulatory molecules,annexins A(ANX A)family can promote or inhibit invasion and metastasis of breast cancer cells by influencing cell membrane and cytoskeleton formation and participating in signaling pathways.ANX A family also plays a role in the apoptosis of breast cancer cells by regulation of pro-apoptotic proteins and cell cycle independent kinases(CDKs)and related pathways.In addition,ANX A family can also promote therapeutic resistance to a large number of drugs.For instance,ANX A1 enhances triple-negative breast cancer resistance by in-ducing epithelial-mesenchymal transformation.ANX A4 induces resistance by forming ANX A4-Fhit complexes and secretion of exosomes containing ANX A6 promotes paclitaxel resistance in breast cancer cells in a YAP1-dependent manner.So ANX A family may be a new target for breast cancer treatment.