Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
1.
Cell ; 184(12): 3178-3191.e18, 2021 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-34022140

RESUMO

Gasdermin B (GSDMB) belongs to a large family of pore-forming cytolysins that execute inflammatory cell death programs. While genetic studies have linked GSDMB polymorphisms to human disease, its function in the immunological response to pathogens remains poorly understood. Here, we report a dynamic host-pathogen conflict between GSDMB and the IpaH7.8 effector protein secreted by enteroinvasive Shigella flexneri. We show that IpaH7.8 ubiquitinates and targets GSDMB for 26S proteasome destruction. This virulence strategy protects Shigella from the bacteriocidic activity of natural killer cells by suppressing granzyme-A-mediated activation of GSDMB. In contrast to the canonical function of most gasdermin family members, GSDMB does not inhibit Shigella by lysing host cells. Rather, it exhibits direct microbiocidal activity through recognition of phospholipids found on Gram-negative bacterial membranes. These findings place GSDMB as a central executioner of intracellular bacterial killing and reveal a mechanism employed by pathogens to counteract this host defense system.


Assuntos
Biomarcadores Tumorais/metabolismo , Interações Hospedeiro-Patógeno , Células Matadoras Naturais/imunologia , Proteínas de Neoplasias/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Shigella flexneri/fisiologia , Ubiquitinação , Animais , Proteínas de Bactérias/metabolismo , Cardiolipinas/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Feminino , Granzimas/metabolismo , Humanos , Lipídeo A/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Viabilidade Microbiana , Complexo de Endopeptidases do Proteassoma/metabolismo , Ligação Proteica , Proteólise , Especificidade por Substrato
2.
PLoS Pathog ; 20(5): e1012010, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38753575

RESUMO

Arboviruses are a diverse group of insect-transmitted pathogens that pose global public health challenges. Identifying evolutionarily conserved host factors that combat arbovirus replication in disparate eukaryotic hosts is important as they may tip the balance between productive and abortive viral replication, and thus determine virus host range. Here, we exploit naturally abortive arbovirus infections that we identified in lepidopteran cells and use bacterial effector proteins to uncover host factors restricting arbovirus replication. Bacterial effectors are proteins secreted by pathogenic bacteria into eukaryotic hosts cells that can inhibit antimicrobial defenses. Since bacteria and viruses can encounter common host defenses, we hypothesized that some bacterial effectors may inhibit host factors that restrict arbovirus replication in lepidopteran cells. Thus, we used bacterial effectors as molecular tools to identify host factors that restrict four distinct arboviruses in lepidopteran cells. By screening 210 effectors encoded by seven different bacterial pathogens, we identify several effectors that individually rescue the replication of all four arboviruses. We show that these effectors encode diverse enzymatic activities that are required to break arbovirus restriction. We further characterize Shigella flexneri-encoded IpaH4 as an E3 ubiquitin ligase that directly ubiquitinates two evolutionarily conserved proteins, SHOC2 and PSMC1, promoting their degradation in insect and human cells. We show that depletion of either SHOC2 or PSMC1 in insect or human cells promotes arbovirus replication, indicating that these are ancient virus restriction factors conserved across invertebrate and vertebrate hosts. Collectively, our study reveals a novel pathogen-guided approach to identify conserved antimicrobial machinery, new effector functions, and conserved roles for SHOC2 and PSMC1 in virus restriction.


Assuntos
Proteínas de Bactérias , Interações Hospedeiro-Patógeno , Replicação Viral , Animais , Replicação Viral/fisiologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Humanos , Arbovírus , Shigella flexneri/patogenicidade , Infecções por Arbovirus/virologia , Linhagem Celular
3.
Ophthalmic Plast Reconstr Surg ; 39(6): e179-e182, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37405752

RESUMO

A 35-year-old woman was treated for extensive squamous cell carcinoma of the nasal septal mucosa with total rhinectomy, including removal of the nasal septum, and chemoradiotherapy. A magnet-retained nasal prosthesis was fitted. She had developed right-sided epiphora from total proximal lacrimal canalicular obstruction, for which an angled Jones lacrimal bypass tube was inserted. The tube, however, intermittently rotated in the nasal cavity, causing recurrent epiphora and irritation at the caruncular site. With the aid of 3-dimensional technology, we designed a septum for the prosthesis that stabilized the tube within the nasal cavity. At the follow-up 2 years later, the patient was satisfied with the nasal prosthesis and lacrimal stent. To our knowledge, this report is the first to describe a patient-specific nasal prosthesis adapted for a Jones tube after total rhinectomy.


Assuntos
Dacriocistorinostomia , Aparelho Lacrimal , Obstrução dos Ductos Lacrimais , Feminino , Humanos , Adulto , Dacriocistorinostomia/métodos , Aparelho Lacrimal/cirurgia , Próteses e Implantes , Impressão Tridimensional
4.
Emerg Infect Dis ; 28(5): 1012-1016, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35271792

RESUMO

We report a severe acute respiratory syndrome coronavirus 2 superspreading event in the Netherlands after distancing rules were lifted in nightclubs, despite requiring a negative test or vaccination. This occurrence illustrates the potential for rapid dissemination of variants in largely unvaccinated populations under such conditions. We detected subsequent community transmission of this strain.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Genômica , Humanos , Países Baixos/epidemiologia , SARS-CoV-2/genética
5.
Nature ; 532(7599): 394-7, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-27007849

RESUMO

Endoplasmic reticulum (ER) stress is a major contributor to inflammatory diseases, such as Crohn disease and type 2 diabetes. ER stress induces the unfolded protein response, which involves activation of three transmembrane receptors, ATF6, PERK and IRE1α. Once activated, IRE1α recruits TRAF2 to the ER membrane to initiate inflammatory responses via the NF-κB pathway. Inflammation is commonly triggered when pattern recognition receptors (PRRs), such as Toll-like receptors or nucleotide-binding oligomerization domain (NOD)-like receptors, detect tissue damage or microbial infection. However, it is not clear which PRRs have a major role in inducing inflammation during ER stress. Here we show that NOD1 and NOD2, two members of the NOD-like receptor family of PRRs, are important mediators of ER-stress-induced inflammation in mouse and human cells. The ER stress inducers thapsigargin and dithiothreitol trigger production of the pro-inflammatory cytokine IL-6 in a NOD1/2-dependent fashion. Inflammation and IL-6 production triggered by infection with Brucella abortus, which induces ER stress by injecting the type IV secretion system effector protein VceC into host cells, is TRAF2, NOD1/2 and RIP2-dependent and can be reduced by treatment with the ER stress inhibitor tauroursodeoxycholate or an IRE1α kinase inhibitor. The association of NOD1 and NOD2 with pro-inflammatory responses induced by the IRE1α/TRAF2 signalling pathway provides a novel link between innate immunity and ER-stress-induced inflammation.


Assuntos
Estresse do Retículo Endoplasmático , Inflamação/metabolismo , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Adaptadora de Sinalização NOD2/metabolismo , Transdução de Sinais , Animais , Proteínas da Membrana Bacteriana Externa/metabolismo , Brucella abortus/imunologia , Brucella abortus/patogenicidade , Linhagem Celular , Ditiotreitol/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/patologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Endorribonucleases/antagonistas & inibidores , Feminino , Humanos , Imunidade Inata , Inflamação/induzido quimicamente , Interleucina-6/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Proteína Adaptadora de Sinalização NOD1/imunologia , Proteína Adaptadora de Sinalização NOD2/imunologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Receptores de Reconhecimento de Padrão/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator 2 Associado a Receptor de TNF/metabolismo , Ácido Tauroquenodesoxicólico/farmacologia , Tapsigargina/farmacologia , Resposta a Proteínas não Dobradas/efeitos dos fármacos
6.
Nephrol Dial Transplant ; 36(1): 121-128, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32124925

RESUMO

BACKGROUND: Fibroblast growth factor 23 (FGF23), a phosphate-regulating hormone that increases early in the course of chronic kidney disease (CKD), is associated with disease progression in patients with established CKD. Here we aimed to investigate the association between plasma FGF23 and new-onset CKD in the general population. METHODS: We included 5253 individuals without CKD who participated in the Prevention of Renal and Vascular Endstage Disease study, a prospective, population-based cohort. Multi-variable Cox regression was used to study the association of plasma C-terminal FGF23 with new-onset CKD, defined as a combined endpoint of estimated glomerular filtration rate (eGFR) <60 mL/min/ 1.73 m2, urinary 24-h albumin excretion (UAE) >30 mg/24 h or both, or with all-cause mortality. RESULTS: The median baseline FGF23 was 68 [interquartile range (IQR) 56-85] RU/mL, eGFR was 95 ± 13 mL/min/1.73 m2 and UAE was 7.8 (IQR 5.8-11.5) mg/24 h. After follow-up of 7.5 (IQR 7.2-8.0) years, 586 participants developed CKD and 214 participants died. A higher FGF23 level was associated with new-onset CKD, independent of risk factors for kidney disease and parameters of bone and mineral homoeostasis {fully adjusted hazard ratio (HR) 1.25 [95% confidence interval (CI) 1.10-1.44] per doubling of FGF23; P = 0.001}. In secondary analyses, FGF23 was independently associated with new-onset eGFR <60 mL/min/1.73 m2 [adjusted HR 1.28 (95% CI 1.00-1.62); P = 0.048] or with UAE >30 mg/24 h [adjusted HR 1.24 (95% CI 1.06-1.45); P = 0.01] individually. A higher FGF23 level was also associated with an increased risk of all-cause mortality [fully adjusted HR 1.30 (95% CI 1.03-1.63); P = 0.03]. CONCLUSIONS: High FGF23 levels are associated with an increased risk of new-onset CKD and all-cause mortality in this prospective population-based cohort, independent of established CKD risk factors.


Assuntos
Biomarcadores/sangue , Fatores de Crescimento de Fibroblastos/sangue , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/mortalidade , Adulto , Idade de Início , Idoso , Progressão da Doença , Feminino , Fator de Crescimento de Fibroblastos 23 , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prognóstico , Estudos Prospectivos , Insuficiência Renal Crônica/epidemiologia , Insuficiência Renal Crônica/patologia , Fatores de Risco , Taxa de Sobrevida
7.
PLoS Med ; 16(6): e1002818, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170159

RESUMO

BACKGROUND: Emerging data in chronic kidney disease (CKD) patients suggest that iron deficiency and higher circulating levels of erythropoietin (EPO) stimulate the expression and concomitant cleavage of the osteocyte-derived, phosphate-regulating hormone fibroblast growth factor 23 (FGF23), a risk factor for premature mortality. To date, clinical implications of iron deficiency and high EPO levels in the general population, and the potential downstream role of FGF23, are unclear. Therefore, we aimed to determine the associations between iron deficiency and higher EPO levels with mortality, and the potential mediating role of FGF23, in a cohort of community-dwelling subjects. METHODS AND FINDINGS: We analyzed 6,544 community-dwelling subjects (age 53 ± 12 years; 50% males) who participated in the Prevention of Renal and Vascular End-Stage Disease (PREVEND) study-a prospective population-based cohort study, of which we used the second survey (2001-2003)-and follow-up was performed for a median of 8 years. We measured circulating parameters of iron status, EPO levels, and plasma total FGF23 levels. Our primary outcome was all-cause mortality. In multivariable linear regression analyses, ferritin (ß = -0.43), transferrin saturation (TSAT) (ß = -0.17), hepcidin (ß = -0.36), soluble transferrin receptor (sTfR; ß = 0.33), and EPO (ß = 0.28) were associated with FGF23 level, independent of potential confounders. During median (interquartile range [IQR]) follow-up of 8.2 (7.7-8.8) years, 379 (6%) subjects died. In multivariable Cox regression analyses, lower levels of TSAT (hazard ratio [HR] per 1 standard deviation [SD], 0.84; 95% confidence interval [CI], 0.75-0.95; P = 0.004) and higher levels of sTfR (HR, 1.15; 95% CI 1.03-1.28; P = 0.01), EPO (HR, 1.17; 95% CI 1.05-1.29; P = 0.004), and FGF23 (HR, 1.20; 95% CI 1.10-1.32; P < 0.001) were each significantly associated with an increased risk of death, independent of potential confounders. Adjustment for FGF23 levels markedly attenuated the associations of TSAT (HR, 0.89; 95% CI 0.78-1.01; P = 0.06), sTfR (HR, 1.08; 95% CI 0.96-1.20; P = 0.19), and EPO (HR, 1.10; 95% CI 0.99-1.22; P = 0.08) with mortality. FGF23 remained associated with mortality (HR, 1.15; 95% CI 1.04-1.27; P = 0.008) after adjustment for TSAT, sTfR, and EPO levels. Mediation analysis indicated that FGF23 explained 31% of the association between TSAT and mortality; similarly, FGF23 explained 32% of the association between sTfR and mortality and 48% of the association between EPO and mortality (indirect effect P < 0.05 for all analyses). The main limitations of this study were the observational study design and the absence of data on intact FGF23 (iFGF23), precluding us from discerning whether the current results are attributable to an increase in iFGF23 or in C-terminal FGF23 fragments. CONCLUSIONS AND RELEVANCE: In this study, we found that functional iron deficiency and higher EPO levels were each associated with an increased risk of death in the general population. Our findings suggest that FGF23 could be involved in the association between functional iron deficiency and increased EPO levels and death. Investigation of strategies aimed at correcting iron deficiency and reducing FGF23 levels is warranted.


Assuntos
Anemia Ferropriva/sangue , Anemia Ferropriva/mortalidade , Eritropoetina/sangue , Fatores de Crescimento de Fibroblastos/sangue , Vigilância da População , Adulto , Idoso , Anemia Ferropriva/diagnóstico , Biomarcadores/sangue , Estudos de Coortes , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Países Baixos , Vigilância da População/métodos
8.
Transfusion ; 59(8): 2575-2583, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31228271

RESUMO

BACKGROUND: In the Netherlands, needle-related events (NREs) including tattoos, piercings, and acupuncture are a reason for temporary blood donor deferral. This study aims to evaluate whether donors with recent NREs had a higher risk of transfusion-transmissible infections (TTIs) compared to donors without recent NREs. STUDY DESIGN AND METHODS: Data from 2006 through 2015 on all blood donation attempts in the Netherlands were collected. Multivariate regression models (for repeated measurements) were used to assess the associations between recent NREs and the acquisition of TTIs. Posttest counseling data were used to determine the most likely risk factor in TTI-positive new and repeat donors. RESULTS: Recent NREs were documented in 97,518 out of 9,266,036 (1.1%) donation attempts; 14,097 (14.5%) NREs resulted in NRE-based donor deferral. Recent NREs reported pre-donation were not associated with an increased risk for TTIs. A total of 29 out of 287 TTI-positive donors (11 repeat donors, 18 new donors) reported a recent NRE pre- and/or post-donation. Recent NREs, all needle-stick injuries, were the likely route of transmission in 12 out of 287 (4.2%) of TTI-positive donors. The donor health questionnaire (DHQ) identified only 1 out of 12 TTI-linked NREs. Non-return after NRE deferral, any deferral, or no deferral was 24, 15, and 5%, respectively. DISCUSSION: Recent tattoos, body piercings, or acupuncture were not associated with an increased risk for TTIs in Dutch donors. Given the lower return rates of donors following a temporary NRE-based deferral, we advocate ending blood donor deferral policies for acupuncture, tattooing, and body piercings, but not needle-stick injuries, in countries where these practices can be considered safe.


Assuntos
Terapia por Acupuntura , Doadores de Sangue , Transfusão de Sangue , Piercing Corporal , Inquéritos e Questionários , Tatuagem , Reação Transfusional/epidemiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Fatores de Risco
9.
Nephrol Dial Transplant ; 34(12): 2057-2065, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30007314

RESUMO

BACKGROUND: Erythropoietin (EPO) has been reported as a novel determinant of fibroblast growth factor 23 (FGF23) production; however, it is unknown whether FGF23 is stimulated by chronic exposure to EPO or by EPO administration in nonpolycystic chronic kidney disease (CKD) models. METHODS: We analyzed the effects of chronic EPO on FGF23 in murine models with chronically high EPO levels and normal kidney function. We studied the effects of exogenous EPO on FGF23 in wild-type mice, with and without CKD, injected with EPO. Also, in four independent human CKD cohorts, we evaluated associations between FGF23 and serum EPO levels or exogenous EPO dose. RESULTS: Mice with high endogenous EPO have elevated circulating total FGF23, increased disproportionately to intact FGF23, suggesting coupling of increased FGF23 production with increased proteolytic cleavage. Similarly, in wild-type mice with and without CKD, a single exogenous EPO dose acutely increases circulating total FGF23 out of proportion to intact FGF23. In these murine models, the bone marrow is shown to be a novel source of EPO-stimulated FGF23 production. In humans, serum EPO levels and recombinant human EPO dose are positively and independently associated with total FGF23 levels across the spectrum of CKD and after kidney transplantation. In our largest cohort of 680 renal transplant recipients, serum EPO levels are associated with total FGF23, but not intact FGF23, consistent with the effects of EPO on FGF23 production and metabolism observed in our murine models. CONCLUSION: EPO affects FGF23 production and metabolism, which may have important implications for CKD patients.


Assuntos
Eritropoetina/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Regulação da Expressão Gênica , Insuficiência Renal Crônica/patologia , Talassemia beta/patologia , Animais , Estudos de Coortes , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Transplante de Rim , Masculino , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Prognóstico , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/cirurgia , Talassemia beta/metabolismo
10.
Infect Immun ; 86(4)2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29339461

RESUMO

The enteric attaching and effacing (A/E) pathogens enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC) and the invasive pathogens enteroinvasive E. coli (EIEC) and Shigella encode type III secretion systems (T3SS) used to inject effector proteins into human host cells during infection. Among these are a group of effectors required for NF-κB-mediated host immune evasion. Recent studies have identified several effector proteins from A/E pathogens and EIEC/Shigella that are involved in suppression of NF-κB and have uncovered their cellular and molecular functions. A novel mechanism among these effectors from both groups of pathogens is to coordinate effector function during infection. This cooperativity among effector proteins explains how bacterial pathogens are able to effectively suppress innate immune defense mechanisms in response to diverse classes of immune receptor signaling complexes (RSCs) stimulated during infection.


Assuntos
Proteínas de Bactérias/imunologia , Proteínas de Escherichia coli/imunologia , Escherichia coli/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Imunomodulação , Shigella/fisiologia , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Núcleo Celular/metabolismo , Disenteria Bacilar/imunologia , Disenteria Bacilar/metabolismo , Disenteria Bacilar/microbiologia , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Humanos , NF-kappa B/metabolismo , Transporte Proteico , Transdução de Sinais , Sistemas de Secreção Tipo III , Ubiquitina/metabolismo
11.
EMBO J ; 33(5): 403-4, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24480478

RESUMO

OspG is a secreted effector kinase from the human pathogen Shigella that is required for the reduction of immune responses during Shigella infection. A new study in The EMBO Journal provides a co-crystal structure of OspG bound to UbcH5c~Ub, revealing how a bacterial kinase can be activated by the host ubiquitin conjugation machinery. These results provide molecular insight into an enigmatic microbial virulence factor that thwarts the host immune surveillance system to cause disease.


Assuntos
Proteínas Quinases/metabolismo , Shigella flexneri/metabolismo , Enzimas de Conjugação de Ubiquitina/metabolismo , Ubiquitina/metabolismo , Fatores de Virulência/metabolismo , Animais , Humanos
12.
J Am Soc Nephrol ; 28(4): 1296-1305, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27856633

RESUMO

Reduction of residual albuminuria during single-agent renin-angiotensin-aldosterone blockade is accompanied by improved cardiorenal outcomes in CKD. We studied the individual and combined effects of the vitamin D receptor activator paricalcitol (PARI) and dietary sodium restriction on residual albuminuria in CKD. In a multicenter, randomized, placebo (PLAC)-controlled, crossover trial, 45 patients with nondiabetic CKD stages 1-3 and albuminuria >300 mg/24 h despite ramipril at 10 mg/d and BP<140/90 mmHg were treated for four 8-week periods with PARI (2 µg/d) or PLAC, each combined with a low-sodium (LS) or regular sodium (RS) diet. We analyzed the treatment effect by linear mixed effect models for repeated measurements. In the intention-to-treat analysis, albuminuria (geometric mean) was 1060 (95% confidence interval, 778 to 1443) mg/24 h during RS + PLAC and 990 (95% confidence interval, 755 to 1299) mg/24 h during RS + PARI (P=0.20 versus RS + PLAC). LS + PLAC reduced albuminuria to 717 (95% confidence interval, 512 to 1005) mg/24 h (P<0.001 versus RS + PLAC), and LS + PARI reduced albuminuria to 683 (95% confidence interval, 502 to 929) mg/24 h (P<0.001 versus RS + PLAC). The reduction by PARI beyond the effect of LS was nonsignificant (P=0.60). In the per-protocol analysis restricted to participants with ≥95% compliance with study medication, PARI did provide further albuminuria reduction (P=0.04 LS + PARI versus LS + PLAC). Dietary adherence was good as reflected by urinary excretion of 174±64 mmol Na+ per day in the combined RS groups and 108±61 mmol Na+ per day in the LS groups (P<0.001). In conclusion, moderate dietary sodium restriction substantially reduced residual albuminuria during fixed dose angiotensin-converting enzyme inhibition. The additional effect of PARI was small and nonsignificant.


Assuntos
Albuminúria/etiologia , Albuminúria/terapia , Dieta Hipossódica , Ergocalciferóis/uso terapêutico , Receptores de Calcitriol/fisiologia , Insuficiência Renal Crônica/complicações , Terapia Combinada , Estudos Cross-Over , Método Duplo-Cego , Humanos
13.
Nephrol Dial Transplant ; 32(1): 73-80, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27220755

RESUMO

Background: Blockade of the renin-angiotensin-aldosterone system (RAAS) retards progression of chronic kidney disease. Yet, in many patients, the renoprotective effect is incomplete. A high circulating level of the phosphaturic hormone fibroblast growth factor 23 is associated with an impaired response to RAAS blockade-based therapy in clinical studies. Therefore, we addressed whether administration of recombinant fibroblast growth factor 23 (FGF23) interferes with the efficacy of angiotensin receptor blocker (ARB) treatment in a mouse model of renal fibrosis [unilateral ureteral obstruction (UUO)]. Methods: UUO mice were treated with losartan (100 mg/L in drinking water), recombinant FGF23 (160 ng/kg i.p. twice daily), their combination or vehicle ( n = 10 per group). Seven days after the UUO procedure, kidney tissue was analyzed for markers of RAAS activity, inflammation and fibrosis using real-time PCR and immunohistochemistry. Results: In the contralateral (non-affected) kidneys of ARB-treated UUO mice, administration of FGF23 reversed the induction of renin, ACE, ACE2 and AT1 receptor mRNA expression, suggesting interference with the physiological response to RAAS blockade by FGF23. Furthermore, recombinant FGF23 infusion prevented ARB-induced klotho upregulation in contralateral kidneys. In the UUO kidneys, klotho was majorly reduced in all groups. Pro-inflammatory gene expression (MCP-1, TNF-α) induced in UUO kidneys was reduced by ARB treatment; this anti-inflammatory effect was reversed by FGF23. In contrast, ARB-induced reduction of (pre-)fibrotic gene expression was not reversed by FGF23. Conclusions: Our findings show pharmacological interaction between exogenous FGF23 and losartan, thus serving as a proof of principle for crosstalk between the FGF23-klotho axis and RAAS.


Assuntos
Aldosterona/metabolismo , Fatores de Crescimento de Fibroblastos/farmacologia , Fibrose/tratamento farmacológico , Losartan/farmacologia , Receptores de Angiotensina/química , Sistema Renina-Angiotensina/efeitos dos fármacos , Obstrução Ureteral/tratamento farmacológico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Modelos Animais de Doenças , Fator de Crescimento de Fibroblastos 23 , Fibrose/metabolismo , Fibrose/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Angiotensina/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Obstrução Ureteral/metabolismo , Obstrução Ureteral/patologia
14.
Annu Rev Microbiol ; 65: 523-41, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21939378

RESUMO

Brucellosis is a zoonotic infection caused primarily by the bacterial pathogens Brucella melitensis and B. abortus. It is acquired by consumption of unpasteurized dairy products or by contact with infected animals. Globally, it is one of the most widespread zoonoses, with 500,000 new cases reported each year. In endemic areas, Brucella infections represent a serious public health problem that results in significant morbidity and economic losses. An important feature of the disease is persistent bacterial colonization of the reticuloendothelial system. In this review we discuss recent insights into mechanisms of intracellular survival and immune evasion that contribute to systemic persistence by the pathogenic Brucella species.


Assuntos
Brucella/fisiologia , Brucelose/microbiologia , Interações Hospedeiro-Patógeno , Zoonoses/microbiologia , Animais , Brucella/genética , Brucella/imunologia , Brucella/isolamento & purificação , Brucelose/epidemiologia , Brucelose/imunologia , Brucelose/transmissão , Humanos , Evasão da Resposta Imune , Saúde Pública , Zoonoses/epidemiologia , Zoonoses/transmissão
15.
Nephrol Dial Transplant ; 31(7): 1081-7, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-25744274

RESUMO

UNLABELLED: Optimal albuminuria reduction is considered essential to halting chronic kidney disease (CKD) progression. Both vitamin D receptor activator (VDRA) treatment and dietary sodium restriction potentiate the efficacy of renin-angiotensin-aldosterone-system (RAAS) blockade to reduce albuminuria. The ViRTUE study addresses whether a VDRA in combination with dietary sodium restriction provides further albuminuria reduction in non-diabetic CKD patients on top of RAAS blockade. The ViRTUE study is an investigator-initiated, prospective, multi-centre, randomized, double-blind (paricalcitol versus placebo), placebo-controlled trial targeting stage 1-3 CKD patients with residual albuminuria of >300 mg/day due to non-diabetic glomerular disease, despite angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use. During run-in, all subjects switched to standardized RAAS blockade (ramipril 10 mg/day) and blood pressure titrated to <140/90 mmHg according to a standardized protocol. Eligible patients are subsequently enrolled and undergo four consecutive study periods in random order of 8 weeks each: (i) paricalcitol (2 µg/day) combined with a liberal sodium diet (∼200 mmol Na(+)/day, i.e. mean sodium intake in the general population), (ii) paricalcitol (2 µg/day) combined with dietary sodium restriction (target: 50 mmol Na(+)/day), (iii) placebo combined with a liberal sodium diet and (iv) placebo combined with dietary sodium restriction. Data are collected at the end of each study period. The primary outcome is 24-h urinary albumin excretion. Secondary study outcomes are blood pressure, renal function (estimated glomerular filtration rate), plasma renin activity and, in a sub-population (N = 9), renal haemodynamics (measured glomerular filtration rate and effective renal plasma flow). A sample size of 50 patients provides 90% power to detect a 23% reduction in albuminuria, assuming a 25% dropout rate. Further reduction of residual albuminuria by combination of VDRA treatment and sodium restriction during single-agent RAAS-blockade will justify long-term studies on cardiorenal outcomes and safety. CLINICAL TRIAL REGISTRATION: NTR2898 (Dutch trial register).


Assuntos
Albuminúria/terapia , Protocolos Clínicos/normas , Ensaios Clínicos como Assunto/métodos , Dieta Hipossódica , Insuficiência Renal Crônica/complicações , Projetos de Pesquisa , Albuminúria/etiologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Humanos
16.
Phys Rev Lett ; 115(6): 065501, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26296121

RESUMO

Density-functional-theory calculations of twin-boundary energies in hexagonal close packed metals reveal anomalously low values for elemental Tc and Re, which can be lowered further by alloying with solutes that reduce the electron per atom ratio. The anomalous behavior is linked to atomic geometries in the interface similar to those observed in bulk tetrahedrally close packed phases. The results establish a link between twin-boundary energetics and the theory of bulk structural stability in transition metals that may prove useful in controlling mechanical behavior in alloy design.

17.
Front Surg ; 11: 1330889, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38550793

RESUMO

An 11-year-old girl presented at the emergency service with a nasal defect caused by a dog bite in the midface. Autologous nose reconstruction in the pediatric population is challenging due to donor site morbidity and remaining facial growth. Temporary prosthetic treatment is difficult to accept due to problems with retention. We present an innovative solution using a 3D printed patient specific titanium implant for support of a nasal prosthesis. With preoperative 3-dimensional planning, the implant can be designed to find fixation in the areas with the best bone quality, avoid potential damage to tooth buds and dental roots and avoid interference to soft tissues such as the nasal septum. Clear communication between the anaplastologist, surgeon and medical engineer is crucial for treatment success. The impact of facial growth is still unclear and will have to be assessed.

18.
bioRxiv ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39282383

RESUMO

A central signal that marshals host defense against many infections is the lymphocyte-derived cytokine interferon-gamma (IFNγ). The IFNγ receptor is expressed on most human cells and its activation leads to the expression of antimicrobial proteins that execute diverse cell-autonomous immune programs. One such immune program consists of the sequential detection, ubiquitylation, and destruction of intracellular pathogens. Recently, the IFNγ-inducible ubiquitin E3 ligase RNF213 was identified as a pivotal mediator of such a defense axis. RNF213 provides host protection against viral, bacterial, and protozoan pathogens. To establish infections, potentially susceptible intracellular pathogens must have evolved mechanisms that subdue RNF213-controlled cell-autonomous immunity. In support of this hypothesis, we demonstrate here that a causative agent of bacillary dysentery, Shigella flexneri, uses the type III secretion system (T3SS) effector IpaH1.4 to induce the degradation of RNF213. S. flexneri mutants lacking IpaH1.4 expression are bound and ubiquitylated by RNF213 in the cytosol of IFNγ-primed host cells. Linear (M1-) and lysine-linked ubiquitin is conjugated to bacteria by RNF213 independent of the linear ubiquitin chain assembly complex (LUBAC). We find that ubiquitylation of S. flexneri is insufficient to kill intracellular bacteria, suggesting that S. flexneri employs additional virulence factors to escape from host defenses that operate downstream from RNF213-driven ubiquitylation. In brief, this study identified the bacterial IpaH1.4 protein as a direct inhibitor of mammalian RNF213 and highlights evasion of RNF213-driven immunity as a characteristic of the human-tropic pathogen Shigella.

19.
bioRxiv ; 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38352400

RESUMO

Arboviruses are a diverse group of insect-transmitted pathogens that pose global public health challenges. Identifying evolutionarily conserved host factors that combat arbovirus replication in disparate eukaryotic hosts is important as they may tip the balance between productive and abortive viral replication, and thus determine virus host range. Here, we exploit naturally abortive arbovirus infections that we identified in lepidopteran cells and use bacterial effector proteins to uncover host factors restricting arbovirus replication. Bacterial effectors are proteins secreted by pathogenic bacteria into eukaryotic hosts cells that can inhibit antimicrobial defenses. Since bacteria and viruses can encounter common host defenses, we hypothesized that some bacterial effectors may inhibit host factors that restrict arbovirus replication in lepidopteran cells. Thus, we used bacterial effectors as molecular tools to identify host factors that restrict four distinct arboviruses in lepidopteran cells. By screening 210 effectors encoded by seven different bacterial pathogens, we identify six effectors that individually rescue the replication of all four arboviruses. We show that these effectors encode diverse enzymatic activities that are required to break arbovirus restriction. We further characterize Shigella flexneri-encoded IpaH4 as an E3 ubiquitin ligase that directly ubiquitinates two evolutionarily conserved proteins, SHOC2 and PSMC1, promoting their degradation in insect and human cells. We show that depletion of either SHOC2 or PSMC1 in insect or human cells promotes arbovirus replication, indicating that these are ancient virus restriction factors conserved across invertebrate and vertebrate hosts. Collectively, our study reveals a novel pathogen-guided approach to identify conserved antimicrobial machinery, new effector functions, and conserved roles for SHOC2 and PSMC1 in virus restriction.

20.
Surgery ; 176(3): 826-834, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38897885

RESUMO

BACKGROUND: There is a lack of evidence regarding the relationship between family involvement and outcomes in gastrointestinal oncology patients after surgery. To evaluate the effect of a family involvement program for patients undergoing oncologic gastrointestinal surgery on unplanned readmissions within 30 days after surgery. METHODS: A multicenter patient-preference cohort study compared 2 groups: patients who participated in the family involvement program versus usual care. The program comprised involvement of family caregivers in care and training of health care professionals in family-centered care. Multivariable regression analyses were used to evaluate the effect of the FIP on the number of unplanned readmissions up to 30 days after surgery. Secondary outcomes included complications sensitive to fundamental care activities, emergency department visits, intensive care unit admissions, hospital length of stay, and the need for professional home care after discharge. RESULTS: Of the 301 patients included, 152 chose the family involvement program, and 149 chose usual care. Postoperative readmissions occurred in 25 (16.4%) patients in the family involvement program group, and 15 (10.1%) in the usual care group (P = .11). A significant reduction of 16.2% was observed in the need for professional home care after discharge in the family involvement program group (P < .01). No significant differences were found between the 2 groups in the other secondary outcomes. CONCLUSION: The family involvement program did not reduce the number of unplanned readmissions, but it led to a substantial reduction in-home care, which suggests an economic benefit from a societal perspective. Implementation of the family involvement program should, therefore, be considered in clinical practice.


Assuntos
Readmissão do Paciente , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Readmissão do Paciente/estatística & dados numéricos , Neoplasias Gastrointestinais/cirurgia , Família , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Resultado do Tratamento , Estudos de Coortes , Adulto , Cuidadores/estatística & dados numéricos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA