RESUMO
Apolipoprotein AV (APOA5) lowers plasma triglyceride (TG) levels by binding to the angiopoietin-like protein 3/8 complex (ANGPTL3/8) and suppressing its capacity to inhibit lipoprotein lipase (LPL) catalytic activity and its ability to detach LPL from binding sites within capillaries. However, the sequences in APOA5 that are required for suppressing ANGPTL3/8 activity have never been defined. A clue to the identity of those sequences was the presence of severe hypertriglyceridemia in two patients harboring an APOA5 mutation that truncates APOA5 by 35 residues ("APOA5Δ35"). We found that wild-type (WT) human APOA5, but not APOA5Δ35, suppressed ANGPTL3/8's ability to inhibit LPL catalytic activity. To pursue that finding, we prepared a mutant mouse APOA5 protein lacking 40 C-terminal amino acids ("APOA5Δ40"). Mouse WT-APOA5, but not APOA5Δ40, suppressed ANGPTL3/8's capacity to inhibit LPL catalytic activity and sharply reduced plasma TG levels in mice. WT-APOA5, but not APOA5Δ40, increased intracapillary LPL levels and reduced plasma TG levels in Apoa5-/- mice (where TG levels are high and intravascular LPL levels are low). Also, WT-APOA5, but not APOA5Δ40, blocked the ability of ANGPTL3/8 to detach LPL from cultured cells. Finally, an antibody against a synthetic peptide corresponding to the last 26 amino acids of mouse APOA5 reduced intracapillary LPL levels and increased plasma TG levels in WT mice. We conclude that C-terminal sequences in APOA5 are crucial for suppressing ANGPTL3/8 activity in vitro and for regulating intracapillary LPL levels and plasma TG levels in vivo.
Assuntos
Apolipoproteínas , Lipase Lipoproteica , Camundongos , Humanos , Animais , Proteínas Semelhantes a Angiopoietina/genética , Proteínas Semelhantes a Angiopoietina/metabolismo , Lipase Lipoproteica/metabolismo , Proteína 3 Semelhante a Angiopoietina , Aminoácidos , Triglicerídeos/metabolismo , Apolipoproteína A-V/genéticaRESUMO
BACKGROUND: Staphylococcus aureus is the most common cause of life-threatening endovascular infections, including infective endocarditis (IE). These infections, especially when caused by methicillin-resistant strains (MRSA), feature limited therapeutic options and high morbidity and mortality rates. METHODS: Herein, we investigated the role of the purine biosynthesis repressor, PurR, in virulence factor expression and vancomycin (VAN) treatment outcomes in experimental IE due to MRSA. RESULTS: The PurR-mediated repression of purine biosynthesis was confirmed by enhanced purF expression and production of an intermediate purine metabolite in purR mutant strain. In addition, enhanced expression of the transcriptional regulators, sigB and sarA, and their key downstream virulence genes (eg, fnbA, and hla) was demonstrated in the purR mutant in vitro and within infected cardiac vegetations. Furthermore, purR deficiency enhanced fnbA/fnbB transcription, translating to increased fibronectin adhesion versus the wild type and purR-complemented strains. Notably, the purR mutant was refractory to significant reduction in target tissues MRSA burden following VAN treatment in the IE model. CONCLUSIONS: These findings suggest that the purine biosynthetic pathway intersects the coordination of virulence factor expression and in vivo persistence during VAN treatment, and may represent an avenue for novel antimicrobial development targeting MRSA.
Assuntos
Antibacterianos , Proteínas de Bactérias , Endocardite Bacteriana , Staphylococcus aureus Resistente à Meticilina , Purinas , Proteínas Repressoras , Infecções Estafilocócicas , Vancomicina , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Animais , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Purinas/biossíntese , Antibacterianos/farmacologia , Vancomicina/farmacologia , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Endocardite Bacteriana/microbiologia , Endocardite Bacteriana/tratamento farmacológico , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Camundongos , Regulação Bacteriana da Expressão Gênica , Modelos Animais de Doenças , Testes de Sensibilidade Microbiana , HumanosRESUMO
BACKGROUND: Lysins (cell wall hydrolases) targeting gram-negative organisms require engineering to permeabilize the outer membrane and access subjacent peptidoglycan to facilitate killing. In the current study, the potential clinical utility for the engineered lysin CF-370 was examined in vitro and in vivo against gram-negative pathogens important in human infections. METHODS: Minimum inhibitory concentration (MICs) and bactericidal activity were determined using standard methods. An in vivo proof-of-concept efficacy study was conducted using a rabbit acute pneumonia model caused by Pseudomonas aeruginosa. RESULTS: CF-370 exhibited potent antimicrobial activity, with MIC50/90 values (in µg/mL) for: P aeruginosa, 1/2; Acinetobacter baumannii, 1/1; Escherichia coli, 0.25/1; Klebsiella pneumoniae, 2/4; Enterobacter cloacae 1/4; and Stenotrophomonas maltophilia 2/8. CF-370 furthermore demonstrated bactericidal activity, activity in serum, a low propensity for resistance, anti-biofilm activity, and synergy with antibiotics. In the pneumonia model, CF-370 alone decreased bacterial densities in lungs, kidneys, and spleen versus vehicle control, and demonstrated significantly increased efficacy when combined with meropenem (vs either agent alone). CONCLUSIONS: CF-370 is the first engineered lysin described with potent broad-spectrum in vitro activity against multiple clinically relevant gram-negative pathogens, as well as potent in vivo efficacy in an animal model of severe invasive multisystem infection.
Assuntos
Antibacterianos , Sinergismo Farmacológico , Meropeném , Testes de Sensibilidade Microbiana , Pneumonia Bacteriana , Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Meropeném/farmacologia , Meropeném/uso terapêutico , Meropeném/administração & dosagem , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Coelhos , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pneumonia Bacteriana/tratamento farmacológico , Pneumonia Bacteriana/microbiologia , Modelos Animais de Doenças , Bactérias Gram-Negativas/efeitos dos fármacos , Biofilmes/efeitos dos fármacosRESUMO
Angiopoietin-like protein (ANGPTL) complexes 3/8 and 4/8 are established inhibitors of LPL and novel therapeutic targets for dyslipidemia. However, the effects of regular exercise on ANGPTL3/8 and ANGPTL4/8 are unknown. We characterized ANGPTL3/8 and ANGPTL4/8 and their relationship with in vivo measurements of lipase activities and cardiometabolic traits before and after a 5-month endurance exercise training intervention in 642 adults from the HERITAGE (HEalth, RIsk factors, exercise Training And GEnetics) Family Study. At baseline, higher levels of both ANGPTL3/8 and ANGPTL4/8 were associated with a worse lipid, lipoprotein, and cardiometabolic profile, with only ANGPTL3/8 associated with postheparin LPL and HL activities. ANGPTL3/8 significantly decreased with exercise training, which corresponded with increases in LPL activity and decreases in HL activity, plasma triglycerides, apoB, visceral fat, and fasting insulin (all P < 5.1 × 10-4). Exercise-induced changes in ANGPTL4/8 were directly correlated to concomitant changes in total cholesterol, LDL-C, apoB, and HDL-triglycerides and inversely related to change in insulin sensitivity index (all P < 7.0 × 10-4). In conclusion, exercise-induced decreases in ANGPTL3/8 and ANGPTL4/8 were related to concomitant improvements in lipase activity, lipid profile, and cardiometabolic risk factors. These findings reveal the ANGPTL3-4-8 model as a potential molecular mechanism contributing to adaptations in lipid metabolism in response to exercise training.
Assuntos
Proteína 3 Semelhante a Angiopoietina , Doenças Cardiovasculares , Adulto , Humanos , Proteínas Semelhantes a Angiopoietina/metabolismo , Triglicerídeos/metabolismo , Lipase , Exercício Físico , Apolipoproteínas B , Lipase Lipoproteica/genética , Proteína 4 Semelhante a AngiopoietinaRESUMO
Objectives: To evaluate the cost-effectiveness of typical pharmaceutical smoking cessation intervention strategies in China in the context of primary cancer prevention. Methods: Markov cohort simulation models were established to simulate the burden of 12 smoking caused cancer, including lung cancer, oral cancer, nasopharyngeal cancer, laryngeal cancer, esophageal cancer, gastric cancer, pancreatic cancer, liver cancer, kidney cancer, bladder cancer, cervical cancer, and acute myeloid leukemia. Taking incremental cost effectiveness ratio (ICER) as the main indicator, the model sets one year as the cycling period for 50 periods and simulates the cohort of 10 000 thirty-five-year-old current smokers with various smoking cessation strategies. To ensure the robustness of conclusion, univariate sensitivity analysis, probability sensitivity analysis, and age-group sensitivity analysis were conducted. Results: The results showed that varenicline intervention was the most cost-effective intervention. Compared to the next most effective option, incremental cost of each additional quality-adjusted life year is 11 140.28 yuan, which is below the threshold of willingness to pay (1 year GDP per capita). The value of ICER increased as the increasing age group of adopting intervention, but neither exceeded the threshold of willingness to pay. One-way sensitivity analysis showed that the value of discount rate, the hazard ratio and cost of intervention strategy had a greater impact on the result of ICER. Conclusion: In China, the use of varenicline to quit smoking is highly cost effective in the context of cancer primary prevention, especially for younger smokers.
Assuntos
Neoplasias Renais , Neoplasias Nasofaríngeas , Abandono do Hábito de Fumar , Humanos , Análise Custo-Benefício , Análise de Custo-Efetividade , Vareniclina , China , Preparações FarmacêuticasRESUMO
Pulpitis is an infectious disease characterized by persistent inflammation of dental pulp and severe pain of patients, root canal treatment increases the risk of tooth fracture, discoloration and reinfection. Therefore, pulp injury repair and pulp regeneration become the new targets of pulpitis treatment. Autophagy is considered as an important defense and protective mechanism, thus plays an important role in preventing the host from excessive inflammatory reaction. There are few reports on the regulative mechanisms and therapeutic strategies of autophagy on pulp inflammation progression, therefore, this paper reviewed the role of autophagy on the progression of pulpitis, also reviewed the research progress of autophagy on dental pulp injury repair and regeneration, aiming to provide theoretical support for further research and clinical application.
Assuntos
Polpa Dentária , Pulpite , Humanos , Autofagia , Inflamação , Pulpite/terapia , RegeneraçãoRESUMO
OBJECTIVE: To investigate the role of RNA-binding motif protein X-linked (RBMX) in regulating the proliferation, migration, invasion and glycolysis in human bladder cancer cells. METHODS: A lentivirus vectors system and RNA interference technique were used to construct bladder cancer 1376 and UC-3 cell models with RBMX overexpression and knockdown, respectively, and successful cell modeling was verified using RT-qPCR and Western blotting. Proliferation and colony forming ability of the cells were evaluated using EdU assay and colony-forming assay, and cell migration and invasion abilities were determined using Transwell experiment. The expressions of glycolysis-related proteins M1 pyruvate kinase (PKM1) and M2 pyruvate kinase (PKM2) were detected using Western blotting. The effects of RBMX overexpression and knockdown on glycolysis in the bladder cancer cells were assessed using glucose and lactic acid detection kits. RESULTS: RT-qPCR and Western blotting confirmed successful construction of 1376 and UC-3 cell models with RBMX overexpression and knockdown. RBMX overexpression significantly inhibited the proliferation, clone formation, migration and invasion of bladder cancer cells, while RBMX knockdown produced the opposite effects. Western blotting results showed that RBMX overexpression increased the expression of PKM1 and decreased the expression of PKM2, while RBMX knockdown produced the opposite effects. Glucose consumption and lactate production levels were significantly lowered in the cells with RBMX overexpression (P < 0.05) but increased significantly following RBMX knockdown (P < 0.05). CONCLUSION: RBMX overexpression inhibits bladder cancer progression and lowers glycolysis level in bladder cancer cells by downregulating PKM2 expression, suggesting the potential of RBMX as a molecular target for diagnosis and treatment of bladder cancer.
Assuntos
Piruvato Quinase , Neoplasias da Bexiga Urinária , Humanos , Linhagem Celular Tumoral , Proliferação de Células , Glucose/farmacologia , Glicólise , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , Neoplasias da Bexiga Urinária/genéticaRESUMO
Objective: To evaluate the clinical application effects of a domestic bone-level implant system for restoring single tooth loss, and provide clinical evidence for the promotion and application of domestic implants. Methods: A prospective, multicenter clinical trial was conducted from April 2018 to January 2020 in three institutions: Department of Oral Implantology, School & Hospital of Stomatology, Wuhan University, Department of Stomatology, The First Affiliated Hospital of Zhejiang University School of Medicine, and Department of Stomatology, The Third Hospital of Hebei Medical University. The trial planned to include 100 patients for single tooth implantation and restoration, followed up for 1 year, to evaluate the implantation success rate and other related outcomes. Results: This study screened a total of 142 patients and ultimately included 100, comprising 43 males and 57 females with age of (47.0±12.2) years. Ninety-eight out of 100 patients completed a one-year follow-up (98.0%), while 2 patients terminated the trial early due to implant loosening (2.0%). After a one-year follow-up, the implants of the 98 patients were all functioning successfully, with a success rate of 98.0% (98/100). The patients were satisfied with the overall restoration effect. Conclusions: This study indicates that the domestic bone-level implant system has achieved favorable short-term clinical outcomes for single-tooth implantation and restoration.
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Bacteremia is a life-threating syndrome often caused by methicillin-resistant (MRSA). Thus, there is an urgent need to develop novel approaches to successfully treat this infection. Staphylococcal accessory regulator A (SarA), a global virulence regulator, plays a critical role in pathogenesis and -lactam antibiotic resistance in . Hypericin is believed to act as an antibiotic, antidepressant, antiviral and non-specific kinase inhibitor. In the current study, we investigated the impact of hypericin on -lactam antibiotics susceptibility and mechanism(s) of its activity. We demonstrated that hypericin significantly decreased the minimum inhibitory concentrations of -lactam antibiotics (.., oxacillin, cefazolin and nafcillin), biofilm formation and fibronectin binding in MRSA strain JE2. In addition, hypericin significantly reduced expression, and subsequently decreased and virulence-related regulators (.., ) and genes (.., and ) expression in the studied MRSA strain. Importantly, the synergistic effect of hypericin with -lactam antibiotic (.., oxacillin) translated into therapeutic outcome in a murine MRSA bacteremia model. These findings suggest that hypericin plays an important role in abrogation of -lactam resistance against MRSA through inhibition, and may allow us to repurpose the use of -lactam antibiotics, which are normally ineffective in the treatment of MRSA infections (.., oxacillin).
RESUMO
As d-amino acids play important roles in the physiological metabolism of bacteria, combination of d-amino acids with antibiotics may provide synergistic antibacterial activity. The aim of the study was to evaluate and activity of d-serine alone and in combination with -lactams against methicillin-resistant (MRSA) strains, and to explore the possible sensitization mechanisms. The activity of d-serine, -lactams alone and in combinations was evaluated both by standard MICs, time-kill curves and checkerboard assays, and by murine systemic infection model as well as neutropenic thigh infection model. An synergistic effect was demonstrated with the combination of d-serine and -lactams against MRSA standard and clinical strains. Importantly, the combinations enhanced the therapeutic efficacy in the animal models as compared to -lactam alone groups. Initial mechanism study suggested possible revision of d-alanine-d-alanine residue to d-alanine-d-serine in peptidoglycan by adding of d-alanine in the medium, which may cause decreased affinity to PBPs during transpeptidation. In conclusion, d-serine had synergistic activity in combination with -lactams against MRSA strains both and . Considering the relatively good safety of d-serine alone or in combination with -lactams, d-serine is worth following up as new anti-MRSA infection strategies.
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Membranous nephropathy (MN), characterized by the presence of diffuse thickening of the glomerular basement membrane and subepithelial in situ immune complex disposition, is the most common cause of idiopathic nephrotic syndrome in adults, with an incidence of 5-10 per million per year. A number of studies have confirmed the relevance of several experimental insights to the pathogenesis of human MN, but the specific biomarkers of MN have not been fully elucidated. As a result, our knowledge of the alterations in histone methylation in MN is unclear. We used chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) to analyze the variations in a methylated histone (H3K9me3) in peripheral blood mononuclear cells from 10 MN patients and 10 healthy subjects. There were 108 genes with significantly different expression in the MN patients compared with the normal controls. In MN patients, significantly increased activity was seen in 75 H3K9me3 genes, and decreased activity was seen in 33, compared with healthy subjects. Five positive genes, DiGeorge syndrome critical region gene 6 (DGCR6), sorting nexin 16 (SNX16), contactin 4 (CNTN4), baculoviral IAP repeat containing 3 (BIRC3), and baculoviral IAP repeat containing 2 (BIRC2), were selected and quantified. There were alterations of H3K9me3 in MN patients. These may be candidates to help explain pathogenesis in MN patients. Such novel findings show that H3K9me3 may be a potential biomarker or promising target for epigenetic-based MN therapies.