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1.
J Biol Chem ; 300(2): 105643, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38199574

RESUMO

Intestinal epithelia express two long myosin light-chain kinase (MLCK) splice variants, MLCK1 and MLCK2, which differ by the absence of a complete immunoglobulin (Ig)-like domain 3 within MLCK2. MLCK1 is preferentially associated with the perijunctional actomyosin ring at steady state, and this localization is enhanced by inflammatory stimuli including tumor necrosis factor (TNF). Here, we sought to identify MLCK1 domains that direct perijunctional MLCK1 localization and their relevance to disease. Ileal biopsies from Crohn's disease patients demonstrated preferential increases in MLCK1 expression and perijunctional localization relative to healthy controls. In contrast to MLCK1, MLCK2 expressed in intestinal epithelia is predominantly associated with basal stress fibers, and the two isoforms have distinct effects on epithelial migration and barrier regulation. MLCK1(Ig1-4) and MLCK1(Ig1-3), but not MLCK2(Ig1-4) or MLCK1(Ig3), directly bind to F-actin in vitro and direct perijunctional recruitment in intestinal epithelial cells. Further study showed that Ig1 is unnecessary, but that, like Ig3, the unstructured linker between Ig1 and Ig2 (Ig1/2us) is essential for recruitment. Despite being unable to bind F-actin or direct recruitment independently, Ig3 does have dominant negative functions that allow it to displace perijunctional MLCK1, increase steady-state barrier function, prevent TNF-induced MLCK1 recruitment, and attenuate TNF-induced barrier loss. These data define the minimal domain required for MLCK1 localization and provide mechanistic insight into the MLCK1 recruitment process. Overall, the results create a foundation for development of molecularly targeted therapies that target key domains to prevent MLCK1 recruitment, restore barrier function, and limit inflammatory bowel disease progression.


Assuntos
Actinas , Actomiosina , Humanos , Actinas/metabolismo , Actomiosina/metabolismo , Citocinese , Células Epiteliais/metabolismo , Mucosa Intestinal/metabolismo , Quinase de Cadeia Leve de Miosina/genética , Quinase de Cadeia Leve de Miosina/metabolismo , Miosinas/metabolismo , Junções Íntimas/metabolismo , Células CACO-2 , Fator de Necrose Tumoral alfa/metabolismo
2.
Nat Rev Gastroenterol Hepatol ; 20(7): 417-432, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37186118

RESUMO

Epithelial tight junctions define the paracellular permeability of the intestinal barrier. Molecules can cross the tight junctions via two distinct size-selective and charge-selective paracellular pathways: the pore pathway and the leak pathway. These can be distinguished by their selectivities and differential regulation by immune cells. However, permeability increases measured in most studies are secondary to epithelial damage, which allows non-selective flux via the unrestricted pathway. Restoration of increased unrestricted pathway permeability requires mucosal healing. By contrast, tight junction barrier loss can be reversed by targeted interventions. Specific approaches are needed to restore pore pathway or leak pathway permeability increases. Recent studies have used preclinical disease models to demonstrate the potential of pore pathway or leak pathway barrier restoration in disease. In this Review, we focus on the two paracellular flux pathways that are dependent on the tight junction. We discuss the latest evidence that highlights tight junction components, structures and regulatory mechanisms, their impact on gut health and disease, and opportunities for therapeutic intervention.


Assuntos
Mucosa , Junções Íntimas , Humanos , Junções Íntimas/química , Junções Íntimas/metabolismo , Permeabilidade , Mucosa Intestinal/metabolismo
3.
Lab Invest ; 103(4): 100036, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36870290

RESUMO

Environmental enteric dysfunction (EED) is characterized by malabsorption and diarrhea that result in irreversible deficits in physical and intellectual growth. We sought to define the expression of transport and tight junction proteins by quantitative analysis of duodenal biopsies from patients with EED. Biopsies from Pakistani children with confirmed EED diagnoses were compared to those from age-matched North American healthy controls, patients with celiac disease, and patients with nonceliac disease with villous atrophy or intraepithelial lymphocytosis. Expression of brush border digestive and transport proteins and paracellular (tight junction) proteins was assessed by quantitative multiplex immunofluorescence microscopy. EED was characterized by partial villous atrophy and marked intraepithelial lymphocytosis. Epithelial proliferation and enteroendocrine, tuft, and Paneth cell numbers were unchanged, but there was significant goblet cell expansion in EED biopsies. Expression of proteins involved in nutrient and water absorption and that of the basolateral Cl- transport protein NKCC1 were also increased in EED. Finally, the barrier-forming tight junction protein claudin-4 (CLDN4) was significantly upregulated in EED, particularly within villous enterocytes. In contrast, expression of CFTR, CLDN2, CLDN15, JAM-A, occludin, ZO-1, and E-cadherin was unchanged. Upregulation of a barrier-forming tight junction protein and brush border and basolateral membrane proteins that support nutrient and water transport in EED is paradoxical, as their increased expression would be expected to be correlated with increased intestinal barrier function and enhanced absorption, respectively. These data suggest that EED activates adaptive intestinal epithelial responses to enhance nutrient absorption but that these changes are insufficient to restore health.


Assuntos
Mucosa Intestinal , Linfocitose , Criança , Humanos , Mucosa Intestinal/metabolismo , Linfocitose/metabolismo , Linfocitose/patologia , Junções Íntimas/metabolismo , Proteínas de Junções Íntimas/metabolismo , Atrofia/metabolismo , Atrofia/patologia
4.
Gut ; 72(5): 870-881, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35537812

RESUMO

OBJECTIVE: Intestinal barrier loss is a Crohn's disease (CD) risk factor. This may be related to increased expression and enzymatic activation of myosin light chain kinase 1 (MLCK1), which increases intestinal paracellular permeability and correlates with CD severity. Moreover, preclinical studies have shown that MLCK1 recruitment to cell junctions is required for tumour necrosis factor (TNF)-induced barrier loss as well as experimental inflammatory bowel disease progression. We sought to define mechanisms of MLCK1 recruitment and to target this process pharmacologically. DESIGN: Protein interactions between FK506 binding protein 8 (FKBP8) and MLCK1 were assessed in vitro. Transgenic and knockout intestinal epithelial cell lines, human intestinal organoids, and mice were used as preclinical models. Discoveries were validated in biopsies from patients with CD and control subjects. RESULTS: MLCK1 interacted specifically with the tacrolimus-binding FKBP8 PPI domain. Knockout or dominant negative FKBP8 expression prevented TNF-induced MLCK1 recruitment and barrier loss in vitro. MLCK1-FKBP8 binding was blocked by tacrolimus, which reversed TNF-induced MLCK1-FKBP8 interactions, MLCK1 recruitment and barrier loss in vitro and in vivo. Biopsies of patient with CD demonstrated increased numbers of MLCK1-FKBP8 interactions at intercellular junctions relative to control subjects. CONCLUSION: Binding to FKBP8, which can be blocked by tacrolimus, is required for MLCK1 recruitment to intercellular junctions and downstream events leading to immune-mediated barrier loss. The observed increases in MLCK1 activity, MLCK1 localisation at cell junctions and perijunctional MLCK1-FKBP8 interactions in CD suggest that targeting this process may be therapeutic in human disease. These new insights into mechanisms of disease-associated barrier loss provide a critical foundation for therapeutic exploitation of FKBP8-MLCK1 interactions.


Assuntos
Doença de Crohn , Animais , Humanos , Camundongos , Células CACO-2 , Doença de Crohn/tratamento farmacológico , Doença de Crohn/metabolismo , Mucosa Intestinal/metabolismo , Camundongos Knockout , Quinase de Cadeia Leve de Miosina/metabolismo , Tacrolimo/farmacologia , Proteínas de Ligação a Tacrolimo/metabolismo , Junções Íntimas/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
5.
Eur J Cell Biol ; 101(2): 151214, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35286924

RESUMO

Sepsis remains an important health problem worldwide due to inefficient treatments often resulting in multi-organ failure. Neutrophil recruitment is critical during sepsis. While neutrophils are required to combat invading bacteria, excessive neutrophil recruitment contributes to tissue damage due to their arsenal of molecular weapons that do not distinguish between host and pathogen. Thus, neutrophil recruitment needs to be fine-tuned to ensure bacterial killing, while avoiding neutrophil-inflicted tissue damage. We recently showed that the actin-binding protein HS1 promotes neutrophil extravasation; and hypothesized that HS1 is also a critical regulator of sepsis progression. We evaluated the role of HS1 in a model of lethal sepsis induced by cecal-ligation and puncture. We found that septic HS1-deficient mice had a better survival rate compared to WT mice due to absence of lung damage. Lungs of septic HS1-deficient mice showed less inflammation, fibrosis, and vascular congestion. Importantly, systemic CLP-induced neutrophil recruitment was attenuated in the lungs, the peritoneum and the cremaster in the absence of HS1. Lungs of HS1-deficient mice produced significantly more interleukin-10. Compared to WT neutrophils, those HS1-deficient neutrophils that reached the lungs had increased surface levels of Gr-1, ICAM-1, and L-selectin. Interestingly, HS1-deficient neutrophils had similar F-actin content and phagocytic activity, but they failed to polymerize actin and deform in response to CXCL-1 likely explaining the reduced systemic neutrophil recruitment in HS1-deficient mice. Our data show that HS1 deficiency protects against sepsis by attenuating neutrophil recruitment to amounts sufficient to combat bacterial infection, but insufficient to induce tissue damage.


Assuntos
Neutrófilos , Sepse , Animais , Modelos Animais de Doenças , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos/fisiologia , Neutrófilos/metabolismo
6.
Front Cell Dev Biol ; 9: 625719, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34012961

RESUMO

The intestinal epithelial barrier (IEB) depends on stable interepithelial protein complexes such as tight junctions (TJ), adherens junctions (AJ), and the actin cytoskeleton. During inflammation, the IEB is compromised due to TJ protein internalization and actin remodeling. An important actin regulator is the actin-related protein 2/3 (Arp2/3) complex, which induces actin branching. Activation of Arp2/3 by nucleation-promoting factors is required for the formation of epithelial monolayers, but little is known about the relevance of Arp2/3 inhibition and endogenous Arp2/3 inhibitory proteins for IEB regulation. We found that the recently identified Arp2/3 inhibitory protein arpin was strongly expressed in intestinal epithelial cells. Arpin expression decreased in response to tumor necrosis factor (TNF)α and interferon (IFN)γ treatment, whereas the expression of gadkin and protein interacting with protein C-kinase α-subunit 1 (PICK1), other Arp2/3 inhibitors, remained unchanged. Of note, arpin coprecipitated with the TJ proteins occludin and claudin-1 and the AJ protein E-cadherin. Arpin depletion altered the architecture of both AJ and TJ, increased actin filament content and actomyosin contractility, and significantly increased epithelial permeability, demonstrating that arpin is indeed required for maintaining IEB integrity. During experimental colitis in mice, arpin expression was also decreased. Analyzing colon tissues from ulcerative colitis patients by Western blot, we found different arpin levels with overall no significant changes. However, in acutely inflamed areas, arpin was significantly reduced compared to non-inflamed areas. Importantly, patients receiving mesalazine had significantly higher arpin levels than untreated patients. As arpin depletion (theoretically meaning more active Arp2/3) increased permeability, we wanted to know whether Arp2/3 inhibition would show the opposite. Indeed, the specific Arp2/3 inhibitor CK666 ameliorated TNFα/IFNγ-induced permeability in established Caco-2 monolayers by preventing TJ disruption. CK666 treatment also attenuated colitis development, colon tissue damage, TJ disruption, and permeability in dextran sulphate sodium (DSS)-treated mice. Our results demonstrate that loss of arpin triggers IEB dysfunction during inflammation and that low arpin levels can be considered a novel hallmark of acute inflammation.

7.
Methods Mol Biol ; 2367: 249-271, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33830456

RESUMO

The intestinal barrier is an essential component of innate host defense. The single layer of epithelial cells that line the intestine must balance barrier function with both active, transcellular and diffusive, paracellular transport. Tight junctions, which link adjacent cells, form a selectively permeable seal that defines both paracellular transport and barrier properties. Molecules can cross tight junctions by either of two distinct routes, termed pore and the leak pathways, that differ in capacity, charge-selectivity, size-selectivity, and responses to physiological and pathophysiological stimuli. A third intestinal permeability route, the unrestricted pathway, reflects loss of the epithelial barrier, as occurs with mucosal damage, is independent of paracellular and transcellular pathways, and is neither charge- nor size-selective.The most commonly used approach for measuring intestinal permeability in vivo involves gavage of FITC-4 kDa dextran and analysis of the quantity recovered in serum. Unfortunately, this method cannot distinguish between leak and unrestricted pathways, as 4 kDa dextran can cross both. Moreover, 4 kDa dextran is too large to cross the pore pathway and, therefore, provides no information regarding this paracellular flux route. Here we describe a multiplex method that allows simultaneous, independent analysis of each pathway.


Assuntos
Junções Íntimas , Claudinas , Dextranos , Mucosa Intestinal , Intestinos , Permeabilidade
8.
Educ Technol Res Dev ; 69(4): 2171-2186, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33584079

RESUMO

In an age of ready access to people, online spaces and information, canonized formal knowledge acquisition is being disrupted. The emergence of socially constructed knowledge based on connected learning is democratising education and re-framing how formal and informal learning is considered. What we currently understand connected learning to be is limited to a combination of individual interests, networked and interdependent relationships with interconnected experiences that transcend temporal, spatial and cultural boundaries. Connected learning does not reduce learning to a phenomenon that takes place exclusively in the restricted spaces of formal education, neither does it focus exclusively on the online learning phenomenon. As such our conceptualisation of connected learning needs to deepen to effectively be able to rationalise how people learn in a digital age. This paper begins to unlock concepts and ideas associated with connected learning using current examples, setting out to build a theoretical model which begins to frame the complexities of conceptualized self-driven global learning interactions.

10.
J Clin Invest ; 130(10): 5197-5208, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32516134

RESUMO

The tight junction protein claudin-2 is upregulated in disease. Although many studies have linked intestinal barrier loss to local and systemic disease, these have relied on macromolecular probes. In vitro analyses show, however, that these probes cannot be accommodated by size- and charge-selective claudin-2 channels. We sought to define the impact of claudin-2 channels on disease. Transgenic claudin-2 overexpression or IL-13-induced claudin-2 upregulation increased intestinal small cation permeability in vivo. IL-13 did not, however, affect permeability in claudin-2-knockout mice. Claudin-2 is therefore necessary and sufficient to effect size- and charge-selective permeability increases in vivo. In chronic disease, T cell transfer colitis severity was augmented or diminished in claudin-2-transgenic or -knockout mice, respectively. We translated the in vitro observation that casein kinase-2 (CK2) inhibition blocks claudin-2 channel function to prevent acute, IL-13-induced, claudin-2-mediated permeability increases in vivo. In chronic immune-mediated colitis, CK2 inhibition attenuated progression in claudin-2-sufficient, but not claudin-2-knockout, mice, i.e., the effect was claudin-2 dependent. Paracellular flux mediated by claudin-2 channels can therefore promote immune-mediated colitis progression. Although the mechanisms by which claudin-2 channels intensify disease remain to be defined, these data suggest that claudin-2 may be an accessible target in immune-mediated disorders, including inflammatory bowel disease.


Assuntos
Claudinas/deficiência , Colite/etiologia , Animais , Claudinas/genética , Claudinas/metabolismo , Colite/imunologia , Colite/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Interleucina-13/administração & dosagem , Mucosa Intestinal/imunologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Regulação para Cima
11.
Proc Natl Acad Sci U S A ; 116(52): 26752-26758, 2019 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-31811025

RESUMO

Neutrophil extravasation is a migratory event in response to inflammation that depends on cytoskeletal dynamics regulated by myosins. Myosin-1e (Myo1e) is a long-tailed class-I myosin that has not yet been studied in the context of neutrophil-endothelial interactions and neutrophil extravasation. Intravital microscopy of TNFα-inflamed cremaster muscles in Myo1e-deficient mice revealed that Myo1e is required for efficient neutrophil extravasation. Specifically, Myo1e deficiency caused increased rolling velocity, decreased firm adhesion, aberrant crawling, and strongly reduced transmigration. Interestingly, we observed a striking discontinuous rolling behavior termed "intermittent rolling," during which Myo1e-deficient neutrophils showed alternating rolling and jumping movements. Surprisingly, chimeric mice revealed that these effects were due to Myo1e deficiency in leukocytes. Vascular permeability was not significantly altered in Myo1e KO mice. Myo1e-deficient neutrophils showed diminished arrest, spreading, uropod formation, and chemotaxis due to defective actin polymerization and integrin activation. In conclusion, Myo1e critically regulates adhesive interactions of neutrophils with the vascular endothelium and neutrophil extravasation. Myo1e may therefore be an interesting target in chronic inflammatory diseases characterized by excessive neutrophil recruitment.

12.
Cell Mol Life Sci ; 76(17): 3349-3361, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31073744

RESUMO

The actin-related protein complex 2/3 (Arp2/3) generates branched actin networks important for many cellular processes such as motility, vesicular trafficking, cytokinesis, and intercellular junction formation and stabilization. Activation of Arp2/3 requires interaction with actin nucleation-promoting factors (NPFs). Regulation of Arp2/3 activity is achieved by endogenous inhibitory proteins through direct binding to Arp2/3 and competition with NPFs or by binding to Arp2/3-induced actin filaments and disassembly of branched actin networks. Arp2/3 inhibition has recently garnered more attention as it has been associated with attenuation of cancer progression, neurotoxic effects during drug abuse, and pathogen invasion of host cells. In this review, we summarize current knowledge on expression, inhibitory mechanisms and function of endogenous proteins able to inhibit Arp2/3 such as coronins, GMFs, PICK1, gadkin, and arpin. Moreover, we discuss cellular consequences of pharmacological Arp2/3 inhibition.


Assuntos
Complexo 2-3 de Proteínas Relacionadas à Actina/metabolismo , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/metabolismo , Citoesqueleto de Actina , Complexo 2-3 de Proteínas Relacionadas à Actina/antagonistas & inibidores , Ligação Competitiva , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Endossomos/metabolismo , Fator de Maturação da Glia/química , Fator de Maturação da Glia/metabolismo , Humanos , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , Tiazolidinas/química , Tiazolidinas/metabolismo
13.
J Immunol ; 202(4): 1239-1249, 2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30626693

RESUMO

A single layer of polarized epithelial cells lining the colonic mucosa create a semipermeable barrier indispensable for gut homeostasis. The role of intestinal epithelial cell (IEC) polarization in the maintenance of the epithelial homeostasis and in the development of inflammatory bowel diseases is not fully understood. In this review, now we report that IEC polarization plays an essential role in the regulation of IL-6/STAT3 signaling in the colonic mucosa. Our results demonstrate that autocrine STAT3 activation in IECs is mediated by the apical secretion of IL-6 in response to the basolateral stimulation with IFN-γ. This process relies on the presence of functional, IFN-γ-producing CD4+ T cells. In the absence of basolateral IFN-γ, the compartmentalization of the IL-6/STAT3 signaling is disrupted, and STAT3 is activated mainly in macrophages. Thus, in this study, we show that during inflammation, IFN-γ regulates IL-6/STAT3 signaling in IEC in the colonic mucosa.


Assuntos
Colite/metabolismo , Colo/metabolismo , Interleucina-6/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Animais , Células CACO-2 , Células Cultivadas , Células Epiteliais/metabolismo , Humanos , Inflamação/metabolismo , Interferon gama/metabolismo , Mucosa Intestinal/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
14.
Dig Dis Sci ; 64(2): 409-420, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30269272

RESUMO

BACKGROUND: Inflammatory bowel diseases (IBD) are multifactorial disorders affecting millions of people worldwide with alarmingly increasing incidences every year. Dysfunction of the intestinal epithelial barrier is associated with IBD pathogenesis, and therapies include anti-inflammatory drugs that enhance intestinal barrier function. However, these drugs often have adverse side effects thus warranting the search for alternatives. Compatible solutes such as bacterial ectoines stabilize cell membranes and proteins. AIM: To unravel whether ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) and homoectoine (4,5,6,7-tetrahydro-2-methyl-1H-(1,3)-diazepine-4-carboxylic acid), a synthetic derivative of ectoine, have beneficial effects during dextran sulfate sodium (DSS)-induced colitis in mice. METHODS/RESULTS: We found that the disease activity index was significantly reduced by both ectoines. DSS-induced edema formation, epithelial permeability, leukocyte recruitment and tissue damage were reduced by ectoine and homoectoine, with the latter having stronger effects. Interestingly, the claudin switch usually observed during colitis (decreased expression of claudin-1 and increased expression of the leaky claudin-2) was completely prevented by homoectoine, whereas ectoine only reduced claudin-2 expression. Concomitantly, only homoectoine ameliorated the drop in transepithelial electrical resistance induced by IFN-γ and TNF-α in Caco-2 cells. Both ectoines inhibited loss of ZO-1 and occludin and prevented IFN-γ/TNF-α-induced increased paracellular flux of 4 kDa FITC-dextran in vitro. Moreover, both ectoines reduced expression of pro-inflammatory cytokines and oxidative stress during colitis. CONCLUSION: While both ectoine and homoectoine have protective effects on the epithelial barrier during inflammation, only homoectoine completely prevented the inflammatory claudin switch in tight junctions. Thus, homoectoine may serve as diet supplement in IBD patients to reach or extend remission.


Assuntos
Diamino Aminoácidos/farmacologia , Claudina-1/efeitos dos fármacos , Claudina-2/efeitos dos fármacos , Colite/patologia , Epitélio/efeitos dos fármacos , Junções Íntimas/efeitos dos fármacos , Animais , Células CACO-2 , Claudina-1/genética , Claudina-1/metabolismo , Claudina-2/genética , Claudina-2/metabolismo , Colite/induzido quimicamente , Colite/metabolismo , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Edema , Impedância Elétrica , Humanos , Técnicas In Vitro , Interferon gama/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Fluorescência , Estresse Oxidativo/efeitos dos fármacos , Permeabilidade/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Junções Íntimas/metabolismo , Fator de Necrose Tumoral alfa/farmacologia
15.
J Glob Antimicrob Resist ; 13: 165-170, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29366723

RESUMO

OBJECTIVES: The incidence of infections caused by multidrug-resistant Pseudomonas aeruginosa (MDR-Pa) has become a concern of increasing relevance nowadays. Ceftolozane/tazobactam (C/T) is a novel fifth-generation cephalosporin/ß-lactamase inhibitor combination with activity against MDR-Pa. METHODS: The clinical records of all patients diagnosed from May 2016 to May 2017 with an infection due to a MDR-Pa treated with C/T were retrospectively reviewed. RESULTS: A total of 23 patients with 24 episodes of infection due to MDR-Pa were included. The minimum inhibitory concentration (MIC) of C/T against MDR-Pa ranged from 0.75-8µg/mL. In 14 cases (58%) the use of C/T was off-label, including 8 respiratory tract infections (RTIs) and 6 skin and soft-tissue infections, whilst in 10 cases the use was for approved indications, including 7 urinary tract infections and 3 intra-abdominal infections. C/T was the first-line therapy in only three cases with a mean±standard deviation treatment duration of 9.3±4 days, and it was associated with another active drug (aminoglycoside or colistin) in 16 cases. The global clinical cure rate was 88% (21/24 episodes), and the 6-week mortality rate was 22% (5/23 patients) being higher in RTIs (37%). In these infections, three patients received 2/1g every 8h (q8h) and were cured without mortality, whilst three (60%) of five patients receiving 1/0.5g q8h died. CONCLUSION: C/T had good clinical responses in different types of infection, including both FDA-accepted and off-label indications. The results support the use of higher doses in RTIs.


Assuntos
Cefalosporinas/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Tazobactam/uso terapêutico , Idoso , Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Colistina/farmacologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Infecções por Pseudomonas/microbiologia , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Estudos Retrospectivos , Tazobactam/farmacologia , Infecções Urinárias/tratamento farmacológico
16.
Sci Rep ; 6: 29003, 2016 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-27357373

RESUMO

Changes in vascular permeability occur during inflammation and the actin cytoskeleton plays a crucial role in regulating endothelial cell contacts and permeability. We demonstrated recently that the actin-binding protein cortactin regulates vascular permeability via Rap1. However, it is unknown if the actin cytoskeleton contributes to increased vascular permeability without cortactin. As we consistently observed more actin fibres in cortactin-depleted endothelial cells, we hypothesised that cortactin depletion results in increased stress fibre contractility and endothelial barrier destabilisation. Analysing the contractile machinery, we found increased ROCK1 protein levels in cortactin-depleted endothelium. Concomitantly, myosin light chain phosphorylation was increased while cofilin, mDia and ERM were unaffected. Secretion of the barrier-stabilising hormone adrenomedullin, which activates Rap1 and counteracts actomyosin contractility, was reduced in plasma from cortactin-deficient mice and in supernatants of cortactin-depleted endothelium. Importantly, adrenomedullin administration and ROCK1 inhibition reduced actomyosin contractility and rescued the effect on permeability provoked by cortactin deficiency in vitro and in vivo. Our data suggest a new role for cortactin in controlling actomyosin contractility with consequences for endothelial barrier integrity.


Assuntos
Adrenomedulina/metabolismo , Permeabilidade Capilar/fisiologia , Cortactina/deficiência , Células Endoteliais/fisiologia , Actomiosina/fisiologia , Animais , Proteínas Contráteis/biossíntese , Proteínas Contráteis/genética , Cortactina/antagonistas & inibidores , Cortactina/genética , Cortactina/fisiologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Pulmão/citologia , Masculino , Camundongos , Interferência de RNA , RNA Interferente Pequeno/genética , Complexo Shelterina , Proteínas de Ligação a Telômeros/metabolismo , Proteínas rap1 de Ligação ao GTP/metabolismo , Quinases Associadas a rho/antagonistas & inibidores , Quinases Associadas a rho/fisiologia
17.
Tissue Barriers ; 4(4): e1228439, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28123925

RESUMO

The correct regulation of tissue barriers is of utmost importance for health. Barrier dysfunction accompanies inflammatory disorders and, if not controlled properly, can contribute to the development of chronic diseases. Tissue barriers are formed by monolayers of epithelial cells that separate organs from their environment, and endothelial cells that cover the vasculature, thus separating the blood stream from underlying tissues. Cells within the monolayers are connected by intercellular junctions that are linked by adaptor molecules to the cytoskeleton, and the regulation of these interactions is critical for the maintenance of tissue barriers. Many endogenous and exogenous molecules are known to regulate barrier functions in both ways. Proinflammatory cytokines weaken the barrier, whereas anti-inflammatory mediators stabilize barriers. Adrenomedullin (ADM) and intermedin (IMD) are endogenous peptide hormones of the same family that are produced and secreted by many cell types during physiologic and pathologic conditions. They activate certain G-protein-coupled receptor complexes to regulate many cellular processes such as cytokine production, actin dynamics and junction stability. In this review, we summarize current knowledge about the barrier-stabilizing effects of ADM and IMD in health and disease.


Assuntos
Adrenomedulina/metabolismo , Células Endoteliais/metabolismo , Junções Intercelulares/metabolismo , Adrenomedulina/química , Adrenomedulina/genética , Animais , Células Endoteliais/citologia , Humanos , Receptores de Adrenomedulina/metabolismo , Transdução de Sinais
18.
Lima; s.n; 2016. 64 p. tab, graf.
Tese em Espanhol | LILACS, LIPECS | ID: biblio-1114445

RESUMO

Objetivo: Determinar la efectividad de un programa educativo en el incremento de conocimiento sobre la enfermedad coronaria en los pacientes que acuden al programa de hipertensión del Hospital Arzobispo Loayza. Material y Método: El estudio es de Tipo cuantitativo, nivel aplicativo, método cuasi-experimental y de corte transversal. La población estuvo conformada por 30 pacientes pertenecientes al programa de hipertensión. La técnica fue la encuesta y el instrumento un cuestionario el cual fue sometido a juicio de expertos, y aplicado antes y después de la ejecución del programa educativo. Resultados: Del 100 por ciento (30) pacientes, antes del programa educativo, 36 por ciento (11) conocen y 64 por ciento (19) no conoce sobre los principales conceptos de la enfermedad coronaria y su prevención, Después de la participación del programa, 93 por ciento (28) conoce y 7 por ciento (2) no conoce sobre los principales conceptos de la enfermedad coronaria y su prevención. Conclusiones: El programa educativo sobre la enfermedad coronaria fue efectivo en el incremento de conocimientos de los pacientes, luego de la aplicación del programa educativo, el cual fue demostrado a través de la prueba de t de Student, obteniéndose un t calc16.8, con un nivel de significancia de a: 0.05, por lo que se acepta la hipótesis de estudio y se comprueba la efectividad del programa educativo.


Objective: To determine the effectiveness of an educational program in increasing knowledge about coronary disease in patients attending the program Archbishop Loayza Hospital hypertension. Material and Methods: The study is quantitative, application level, quasi-experimental and cross-sectional method. The population consisted of 30 patients in the hypertension program. The technique was the survey instrument and a questionnaire which was submitted to expert opinion, and applied before and after the execution of the educational program. Results: Of 100 per cent (30) patients, before the educational program, 36 per cent (11) know and 64 per cent (19) does not know about the main concepts of coronary disease and its prevention, after program participation, 93 per cent (28) knows and 7 per cent (2) does not know about the main concepts of coronary disease and its prevention. Conclusions: The educational program on coronary disease was effective in increasing knowledge of patients after the implementation of the educational program, which was demonstrated through testing Student t give a t calc16.8 with a significance level a: 0.05, so the study hypothesis is accepted and the effectiveness of the educational program is checked.


Assuntos
Masculino , Feminino , Humanos , Doença das Coronárias/prevenção & controle , Educação de Pacientes como Assunto , Enfermagem Cardiovascular , Hipertensão/complicações , Estudos Transversais
19.
Rev Enferm ; 31(3): 7-10, 2008 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-18444365

RESUMO

The use of oral anti-diabetes medicines should be considered when nutritional control methods and physical exercise programs have failed. These medicines have several types of active mechanisms: to stimulate pancreatic secretion of insulin, to delay the absorption of carbohydrates in the intestines, to sensitize tissues to the action of insulin. Sulfonylureas are the pharmaceutical group most commonly utilized in the treatment of type 2 diabetes mellitus.


Assuntos
Biguanidas/uso terapêutico , Diabetes Mellitus/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Piperidinas/uso terapêutico , Compostos de Sulfonilureia/uso terapêutico , Trissacarídeos/uso terapêutico , Administração Oral , Biguanidas/efeitos adversos , Índice de Massa Corporal , Contraindicações , Humanos , Hipoglicemiantes/administração & dosagem , Motivação , Obesidade/epidemiologia , Piperidinas/efeitos adversos , Compostos de Sulfonilureia/efeitos adversos , Trissacarídeos/efeitos adversos
20.
Metas enferm ; 11(2): 62-70, mar. 2008. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-94417

RESUMO

La diabetes es una enfermedad crónica que afecta a un gran número de personas y que exige una atención continuada, interdisciplinar y en muchas ocasiones especializada para lograr un buen control metabólico, sin detrimento de la calidad de vida. El tratamiento insulínico constituye uno de los pilares terapéuticos fundamentales en muchos pacientes, dado que contribuye a mantener un control glucémico estricto, reduciendo así las complicaciones a corto y largo plazo. La finalidad de este trabajo es proporcionar una visión actualizada de las insulinas disponibles (AU)


Diabetes is a chronic disease that affects a large number of people requiring continued, interdisciplinary medical care and, on many occasions, specialised care in order to achieve good metabolic control, with no detriment to the quality of life of the sufferer. Insulin treatment constitutes one of the fundamental therapeutic pillars in many patients, as it helps maintain strict glycemic control, reducing short and long term complications. The aim of this work is to provide an updated view of available insulins (AU)


Assuntos
Humanos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Insulina/administração & dosagem , Cuidados de Enfermagem/métodos , Sistemas de Infusão de Insulina , Índice Glicêmico
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