RESUMO
The intermediate filament vimentin is present in immune cells and is implicated in proinflammatory immune responses. Whether and how it supports antimicrobial activities of neutrophils are not well established. Here, we developed an immortalized neutrophil model to examine the requirement of vimentin. We demonstrate that vimentin restricts the production of proinflammatory cytokines and reactive oxygen species (ROS), but enhances phagocytosis and swarming. We observe that vimentin is dispensable for neutrophil extracellular trap (NET) formation, degranulation, and inflammasome activation. Moreover, gene expression analysis demonstrated that the presence of vimentin was associated with changes in expression of multiple genes required for mitochondrial function and ROS overproduction. Treatment of wild-type cells with rotenone, an inhibitor for complex I of the electron transport chain, increases the ROS levels. Likewise, treatment with mitoTEMPO, a SOD mimetic, rescues the ROS production in cells lacking vimentin. Together, these data show vimentin regulates neutrophil antimicrobial functions and alters ROS levels through regulation of mitochondrial activity.
Assuntos
Mitocôndrias , Neutrófilos , Espécies Reativas de Oxigênio , Vimentina , Espécies Reativas de Oxigênio/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Vimentina/metabolismo , Mitocôndrias/metabolismo , Animais , Camundongos , Inflamação/imunologia , Inflamação/metabolismo , Armadilhas Extracelulares/imunologia , Armadilhas Extracelulares/metabolismo , Fagocitose , Inflamassomos/metabolismo , Inflamassomos/imunologia , Citocinas/metabolismo , Humanos , Rotenona/farmacologiaRESUMO
Background: Warfarin is considered the primary oral anticoagulant for patients with atrial fibrillation and end-stage renal disease (ESRD) requiring dialysis. Although warfarin can offer significant stroke prevention in this population, the accompanying major bleeding risks make warfarin nearly prohibitive. Apixaban was shown to be superior to warfarin in preventing stroke or systemic embolism, with a lower risk of bleeding and mortality in a large, randomized trial of individuals with mostly normal renal function but none with ESRD. Methods: We systematically reviewed evidence comparing apixaban versus warfarin for atrial fibrillation in this population, and evaluated outcomes of stroke or systemic embolism, and major bleeding using random-effects models. The main safety outcome was major bleeding, and the main effectiveness outcome was stroke or systemic embolism. Results: We found five observational studies of 10 036 patients (2638 receiving apixaban, and 7398 receiving warfarin) meeting inclusion criteria. Pooled analysis demonstrated a significant reduction in major bleeding with apixaban as compared to warfarin (odds ratio [OR] 0.51, 95% confidence interval [CI] 0.42-0.61; p < .0001). Apixaban was also associated with a reduction in intracranial bleeding (OR 0.58, 95% CI 0.37-0.92; p = .02) and in gastrointestinal bleeding (OR 0.61, 95% CI 0.51-0.73; p < .0001). Furthermore, apixaban was associated with a reduction in stroke/systemic embolism (OR 0.64, 95% CI 0.50-0.82; p < .0001). Conclusion: Apixaban was associated with superior outcomes and reduced adverse events compared to warfarin in observational studies of patients with atrial fibrillation on dialysis. Randomized controlled studies are needed to confirm these findings.
RESUMO
The intermediate filament vimentin is present in immune cells and is implicated in proinflammatory immune responses. Whether and how it supports antimicrobial activities of neutrophils is not well established. Here, we developed an immortalized neutrophil model to examine the requirement of vimentin. We demonstrate that vimentin restricts the production of proinflammatory cytokines and reactive oxygen species (ROS), but enhances phagocytosis and swarming. We observe that vimentin is dispensable for neutrophil extracellular trap (NET) formation, degranulation, and inflammasome activation. Moreover, gene expression analysis demonstrated that the presence of vimentin was associated with changes in expression of multiple genes required for mitochondrial function and ROS overproduction. Treatment of wild-type cells with rotenone, an inhibitor for complex I of the electron transport chain, increases the ROS levels. Likewise, treatment with mitoTEMPO, a SOD mimetic, rescues the ROS production in cells lacking vimentin. Together, these data show vimentin regulates neutrophil antimicrobial functions and alters ROS levels through regulation of mitochondrial activity.
RESUMO
For multiple intracellular bacterial pathogens, the ability to spread directly into adjacent epithelial cells is an essential step for disease in humans. For pathogens such as Shigella, Listeria, Rickettsia, and Burkholderia, this intercellular movement frequently requires the pathogens to manipulate the host actin cytoskeleton and deform the plasma membrane into structures known as protrusions, which extend into neighboring cells. The protrusion is then typically resolved into a double-membrane vacuole (DMV) from which the pathogen quickly escapes into the cytosol, where additional rounds of intercellular spread occur. Significant progress over the last few years has begun to define the mechanisms by which intracellular bacterial pathogens spread. This review highlights the interactions of bacterial and host factors that drive mechanisms required for intercellular spread with a focus on how protrusion structures form and resolve.
RESUMO
An electrochemical method for the synthesis of N-substituted 2-aminobenzimidazoles through a NaI-mediated desulfurization-cyclization process is reported. This electrosynthesis method utilizes cost-effective NaI as both a mediator and an electrolyte in a catalytic amount (0.2 equiv), replacing traditional oxidizing reagents. N-Substituted o-phenylenediamines and isothiocyanates undergo a thiourea formation/cyclization/desulfurization process to provide N-substituted 2-aminobenzimidazoles (55 examples, up to 98% yield) in a single reaction vessel. Importantly, this electrochemical methodology is applicable to gram-scale synthesis, maintaining reaction efficiency.
RESUMO
Objectives: This study assessed the diagnostic value of a monoclonal immunoassay stool antigen test (HpSA) for Helicobacter pylori (H. pylori) infection and the eradication outcomes. Methods: Children undergoing digestive endoscopy at 2 Children's Hospitals in Ho Chi Minh City were recruited. Treatment was offered to H. pylori-infected children. Stool samples were collected on the same day as the endoscopy procedure and after 6 weeks post-treatment for HpSA. Diagnostic value and optimal cutoff of HpSA were assessed using biopsy-based tests as the gold standard. Eradication was defined as a negative HpSA post-treatment. Ethical approval was obtained, and informed consent was signed by the participants. Results: In total, 394 patients participated in the study. The most common symptoms were epigastric pain (74.6%) and vomiting (37.3%). H. pylori status was positive in 78% of patients (306/394), doubtful in 10.1%, and negative in 12.2%. HpSA was positive in 73.2% (142/194). Excluding doubtful infections, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of HpSA were 87.4%, 95.2%, 99.2%, 51.3%, and 88.4%, respectively. The optimal cutoff value of 0.148 provided similar accuracy to the recommended cutoff. The eradication rate was 56.1% in per-protocol analysis and 27.9% in intention-to-treat analysis. Treatment success was higher in boys, but lower among malnourished children and those infected with cagA+ strains. Conclusions: The HpSA is reliable for identifying H. pylori infection in epidemiological studies and assessing eradication outcomes. The low eradication rate highlights the need for an appropriate intervention strategy in Vietnamese children.
RESUMO
OBJECTIVES: Prediction models based on traditional risk factors underestimate cardiovascular (CV) risk in systemic lupus erythematosus (SLE). In a large sample of unselected SLE patients, we investigated cross-sectional associations of NT-proBNP with cardiovascular damage (CVD). METHODS: Serum NT-proBNP was measured in SLE patients enrolled in the MUHC Lupus Clinic registry. Serum were collected between March 2022 and April 2023 at annual research visits. The primary outcome was CVD identified on the SLICC Damage Index. Factors associated with CVD and NT-proBNP levels were determined. RESULTS: Overall, 270 SLE patients (female 91%, median age 50.7 [1st quartile- 3rd quartile : 39.6-62.1] years) were analyzed for the primary outcome. Among them, 33 (12%) had CVD. The ROC curve for NT-proBNP demonstrated strong associations with CVD (AUC 0.78, 95% CI 0.69-0.87) with a threshold of 133 pg/ml providing the best discrimination for those with/without CVD. Hypertension (OR 3.3, 95% CI 1.2-9.0), dyslipidaemia (OR 3.6, 95% CI 1.3-9.6) and NT-proBNP > 133 pg/ml (OR 7.0, 95% CI, 2.6-19.1) were associated with CVD in the multivariable logistic regression model. Increased NT-proBNP levels were associated with age (OR 4.2, 95% CI 2.2-8.3), ever smoking (OR 1.9, 95% CI 1.0-3.5), reduced eGFR (4.1, 95% CI 1.3-13.1), prior pericarditis/pleuritis (OR 2.5, 95% CI 1.4-4.5) and aPL antibodies (OR 2.6, 95% CI 1.4-4.9). CONCLUSION: NT-proBNP is a biomarker for CV damage in SLE. The novel associations of NT-proBNP levels with prior pericarditis/pleuritis and aPL antibodies suggest new avenues for research to better understand what drives CV risk in SLE.
RESUMO
In this study, we present an electrochemical approach for the synthesis of guanidines from isothiocyanates and amines in a single reaction vessel. This one-pot operation takes place in aqueous media, utilizing an undivided cell setup with NaI serving as both the electrolyte and mediator. The process involves the in situ generation of thiourea, followed by electrolytic guanylation with amines. Under ambient temperature conditions, we successfully demonstrated the formation of 30 different guanidine compounds, achieving yields ranging from fair to excellent. Furthermore, the synthesis method could be carried out on a gram scale with a good yield. This protocol stands out for its cost-effectiveness, step-economical design, high tolerance towards various functional groups, and environmentally friendly reaction conditions.
RESUMO
PURPOSE: The National Comprehensive Cancer Network guidelines state that the oxaliplatin dose of 85â mg/m2 used in various gastrointestinal cancer regimens may be infused over a rapid rate of 85â min instead of the standard time of 120â min. We evaluated the safety outcomes of rapid administration of oxaliplatin compared to standard infusion. METHODS: We performed a retrospective, cohort study by chart review. Adult patients who received oxaliplatin as part of a FOLFOX, FOLFOXIRI, or FOLRINOX chemotherapy regimen from January 1, 2018, through June 30, 2021, were included. Primary outcomes were the incidence of hypersensitivity reaction (HSR) and treatment modification of oxaliplatin due to adverse drug events. Secondary outcomes included peripheral neuropathy (PN), myelosuppressive signs, and oxaliplatin-related emergency department visit and/or hospital admission. RESULTS: A total of 178 patients were included (90 and 88 in the rapid-rate and standard-rate groups, respectively). Rapid-rate oxaliplatin was not associated with increased HSR or difference in toxicity requiring dose reduction, delayed dose, or slowed infusion rate, but was associated with increased rate of permanent discontinuation of oxaliplatin, 7.8% and 1.1% in the rapid-rate group and standard-rate groups, respectively (p = 0.032). Peripheral neuropathy occurred in 72.2% and 42% of patients in the rapid-rate group and standard-rate groups, respectively (relative risk for PN, 2.09; 95%, CI: 1.43-3.04; p < .001). There were no differences in any other adverse drug event measured. CONCLUSION: Rapid-rate oxaliplatin was associated with minimal treatment modifications; however, there was an increase in PN incidence. A faster rate of oxaliplatin administration may not be worth the increased risk of PN.
RESUMO
The levels of non-coding RNAs (ncRNAs) are regulated by transcription, RNA processing, and RNA degradation pathways. One mechanism for the degradation of ncRNAs involves the addition of oligo(A) tails by non-canonical poly(A) polymerases, which then recruit processive sequence-independent 3' to 5' exonucleases for RNA degradation. This pathway of decay is also regulated by three 3' to 5' exoribonucleases, USB1, PARN, and TOE1, which remove oligo(A) tails and thereby can protect ncRNAs from decay in a manner analogous to the deubiquitination of proteins. Loss-of-function mutations in these genes lead to premature degradation of some ncRNAs and lead to specific human diseases such as Poikiloderma with Neutropenia (PN) for USB1, Dyskeratosis Congenita (DC) for PARN and Pontocerebellar Hypoplasia type 7 (PCH7) for TOE1. Herein, we review the biochemical properties of USB1, PARN, and TOE1, how they modulate ncRNA levels, and their roles in human diseases.
Assuntos
Exorribonucleases , RNA não Traduzido , Humanos , Disceratose Congênita/fisiopatologia , Exorribonucleases/genética , Exorribonucleases/metabolismo , Neutropenia/fisiopatologia , Estabilidade de RNA/genética , RNA não Traduzido/genética , Mutação com Perda de FunçãoRESUMO
Cholesterol is essential for cellular function and is stored as cholesteryl esters (CEs). CEs biosynthesis is catalyzed by the enzymes acyl-CoA:cholesterol acyltransferase 1 and 2 (ACAT1 and ACAT2), with ACAT1 being the primary isoenzyme in most cells in humans. In Alzheimer's Disease, CEs accumulate in vulnerable brain regions. Therefore, ACATs may be promising targets for treating AD. F12511 is a high-affinity ACAT1 inhibitor that has passed phase 1 safety tests for antiatherosclerosis. Previously, we developed a nanoparticle system to encapsulate a large concentration of F12511 into a stealth liposome (DSPE-PEG2000 with phosphatidylcholine). Here, we injected the nanoparticle encapsulated F12511 (nanoparticle F) intravenously (IV) in wild-type mice and performed an HPLC/MS/MS analysis and ACAT enzyme activity measurement. The results demonstrated that F12511 was present within the mouse brain after a single IV but did not overaccumulate in the brain or other tissues after repeated IVs. A histological examination showed that F12511 did not cause overt neurological or systemic toxicity. We then showed that a 2-week IV delivery of nanoparticle F to aging 3xTg AD mice ameliorated amyloidopathy, reduced hyperphosphorylated tau and nonphosphorylated tau, and reduced neuroinflammation. This work lays the foundation for nanoparticle F to be used as a possible therapy for AD and other neurodegenerative diseases.
Assuntos
Doença de Alzheimer , Humanos , Camundongos , Animais , Camundongos Transgênicos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Lipossomos , Distribuição Tecidual , Espectrometria de Massas em Tandem , Acetil-CoA C-Acetiltransferase/metabolismoRESUMO
PURPOSE: The aim of this study was to estimate the cost-effectiveness of a very low-protein diet (VLPD) supplemented with ketoanalogues of essential amino acids compared with a conventional low-protein diet (LPD) in Vietnam. METHODS: The study was conducted from payer (base case), patient, and societal perspectives. A Markov model simulated costs and quality-adjusted life-years (QALYs) for patients with chronic kidney disease stage 4 or 5 (CKD4+) who were followed up during their lifetimes. Patients received a VLPD (0.3- to 0.4-g/kg/d diet) supplemented with ketoanalogues (5 kg/d [1 tablet]) versus LPD (0.6 g/kg/d, mixed proteins). In each model cycle, patient transitions among the health states-CKD4+ (nondialysis), dialysis, and death-were based on transition probabilities taken from the published literature. The time horizon covered the cohort's lifetime. Utilities and costs were estimated from literature review and projected for the lifespan considered in the model. Probabilistic and deterministic sensitivity analyses were performed. FINDINGS: The ketoanalogue-supplemented VLPD increased survival and QALYs compared with the LPD. From a payer's perspective, total cost of care in Vietnam was â«216,854,268 (8684/$9242) per patient with LPD versus â«200,928,819 (8046/$8563) per patient with a supplemented VLPD (sVLPD) (difference, -â«15,925,449 [-638/-$679]). From a patient's perspective, total cost of care in Vietnam was â«217,872,043 (8724/$9285) per patient with LPD versus â«116,015,672 (4646/$4944) per patient with sVLPD (difference, -â«101,856,371 [-4,079/ -$4341]). From a societal perspective, total cost of care in Vietnam was â«434,726,312 (17,408/-$18,527) per patient with LPD versus â«316,944,491 (12,692/ $13,508) per patient with sVLPD (difference, -â«117,781,820 [-4716 /$5020). IMPLICATIONS: Ketoanalogue-supplemented VLPD lowered costs compared with LPD in all 3 perspectives considered.
Assuntos
Dieta com Restrição de Proteínas , Insuficiência Renal Crônica , Humanos , Vietnã , Insuficiência Renal Crônica/terapia , Diálise Renal , Suplementos Nutricionais , Análise Custo-Benefício , Anos de Vida Ajustados por Qualidade de VidaRESUMO
BACKGROUND: It remains unclear whether racial and ethnic disparities for atherosclerotic cardiovascular disease (ASCVD) persist within universal health care systems. We aimed to explore long-term ASCVD outcomes within a single-payer health care system with extensive drug coverage in Québec, Canada. METHODS: CARTaGENE (CaG) is a population-based prospective cohort study of individuals aged 40 to 69 years. We included only participants without previous ASCVD. The primary composite endpoint was time to the first ASCVD event (cardiovascular death, acute coronary syndrome, ischemic stroke-transient ischemic attack, or peripheral arterial vascular event). RESULTS: The study cohort included 18,880 participants followed for a median of 6.6 years (2009 to 2016). The mean age was 52 years, and 52.4% were female. After further adjustment for socioeconomic and cardiovascular factors, the increase in ASCVD risk for South Asians (SAs) was attenuated (hazard ratio [HR], 1.41; 95% confidence interval [CI], 0.75, 2.67), whereas Black participants' risk was lower (HR, 0.52; 95% CI, 0.29, 0.95) compared with White participants. After similar adjustments, there were no significant differences in ASCVD outcomes among the Middle Eastern, Hispanic, East-Southeast Asian, Indigenous, and mixed race-ethnicities participants and the White participants. CONCLUSIONS: After adjustment for CV risk factors, the risk of ASCVD was attenuated in the SA CaG participants. Intensive risk-factor modification may mitigate the ASCVD risk of the SAs. Within a universal health care context and comprehensive drug coverage, the ASCVD risk was lower among Black compared with White CaG participants. Future studies are needed to confirm whether universal and liberal access to health care and medications can reduce the rates of ASCVD among the Black population.
Assuntos
Aterosclerose , Doenças Cardiovasculares , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Etnicidade , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/terapia , Doenças Cardiovasculares/complicações , Estudos Prospectivos , Assistência de Saúde Universal , Medição de Risco , Aterosclerose/epidemiologia , Fatores de RiscoRESUMO
Mutations in the 3' to 5' RNA exonuclease USB1 cause hematopoietic failure in poikiloderma with neutropenia (PN). Although USB1 is known to regulate U6 small nuclear RNA maturation, the molecular mechanism underlying PN remains undetermined, as pre-mRNA splicing is unaffected in patients. We generated human embryonic stem cells harboring the PN-associated mutation c.531_delA in USB1 and show that this mutation impairs human hematopoiesis. Dysregulated microRNA (miRNA) levels in USB1 mutants during blood development contribute to hematopoietic failure, because of a failure to remove 3'-end adenylated tails added by PAPD5/7. Modulation of miRNA 3'-end adenylation through genetic or chemical inhibition of PAPD5/7 rescues hematopoiesis in USB1 mutants. This work shows that USB1 acts as a miRNA deadenylase and suggests PAPD5/7 inhibition as a potential therapy for PN.
Assuntos
Hematopoese , MicroRNAs , Neutropenia , Diester Fosfórico Hidrolases , Humanos , Hematopoese/genética , Células-Tronco Embrionárias Humanas , MicroRNAs/genética , MicroRNAs/metabolismo , Neutropenia/genética , Neutropenia/terapia , Diester Fosfórico Hidrolases/genética , Diester Fosfórico Hidrolases/metabolismo , MutaçãoRESUMO
Dengue and Zika viruses are mosquito-borne flaviviruses burdening millions every year with hemorrhagic fever and neurological symptoms. Baicalein was previously reported as a potential anti-flaviviral candidate and halogenation of flavones and flavanones potentiated their antiviral efficacies. Here, we reported that a chemically modified 8-bromobaicalein effectively inhibited all dengue serotypes and Zika viruses at 0.66-0.88 micromolar in cell-based system. The compound bound to dengue serotype 2 conserved pocket and inhibited the dengue RdRp activity with 6.93 fold more than the original baicalein. Moreover, the compound was mildly toxic against infant and adult C57BL/6 mice despite administering continuously for 7 days. Therefore, the 8-bromobaicalein should be investigated further in pharmacokinetics and efficacy in an animal model.
Assuntos
Vírus da Dengue , Dengue , Flavivirus , Infecção por Zika virus , Zika virus , Animais , Camundongos , Dengue/tratamento farmacológico , Camundongos Endogâmicos C57BLRESUMO
Cholesterol is stored as cholesteryl esters by the enzymes acyl-CoA:cholesterol acyltransferases/sterol O:acyltransferases (ACATs/SOATs). ACAT1 blockade (A1B) ameliorates the pro-inflammatory responses of macrophages to lipopolysaccharides (LPS) and cholesterol loading. However, the mediators involved in transmitting the effects of A1B in immune cells is unknown. Microglial Acat1/Soat1 expression is elevated in many neurodegenerative diseases and in acute neuroinflammation. We evaluated LPS-induced neuroinflammation experiments in control vs. myeloid-specific Acat1/Soat1 knockout mice. We also evaluated LPS-induced neuroinflammation in microglial N9 cells with and without pre-treatment with K-604, a selective ACAT1 inhibitor. Biochemical and microscopy assays were used to monitor the fate of Toll-Like Receptor 4 (TLR4), the receptor at the plasma membrane and the endosomal membrane that mediates pro-inflammatory signaling cascades. In the hippocampus and cortex, results revealed that Acat1/Soat1 inactivation in myeloid cell lineage markedly attenuated LPS-induced activation of pro-inflammatory response genes. Studies in microglial N9 cells showed that pre-incubation with K-604 significantly reduced the LPS-induced pro-inflammatory responses. Further studies showed that K-604 decreased the total TLR4 protein content by increasing TLR4 endocytosis, thus enhancing the trafficking of TLR4 to the lysosomes for degradation. We concluded that A1B alters the intracellular fate of TLR4 and suppresses its pro-inflammatory signaling cascade in response to LPS.
Assuntos
Lipopolissacarídeos , Microglia , Animais , Camundongos , Aciltransferases/metabolismo , Colesterol/metabolismo , Lipopolissacarídeos/toxicidade , Lipopolissacarídeos/metabolismo , Camundongos Knockout , Microglia/metabolismo , Doenças Neuroinflamatórias , Receptor 4 Toll-Like/metabolismoRESUMO
Poly(A)-specific ribonuclease (PARN) is a 3'-exoribonuclease that removes poly(A) tails from the 3' end of RNAs. PARN is known to deadenylate some ncRNAs, including hTR, Y RNAs, and some miRNAs and thereby enhance their stability by limiting the access of 3' to 5' exonucleases recruited by oligo(A) tails. Several PARN-regulated miRNAs target p53 mRNA, and PARN knockdown leads to an increase of p53 protein levels in human cells. Thus, PARN inhibitors might be used to induce p53 levels in some human tumors and act as a therapeutic strategy to treat cancers caused by repressed p53 protein. Herein, we used computational-based molecular docking and high-throughput screening (HTS) to identify small molecule inhibitors of PARN. Validation with in vitro and cell-based assays, identified 4 compounds, including 3 novel compounds and pyrimidopyrimidin-2-one GNF-7, previously shown to be a Bcr-Abl inhibitor, as PARN inhibitors. These inhibitors can be used as tool compounds and as lead compounds for the development of improved PARN inhibitors.