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1.
Cureus ; 16(3): e57312, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38690488

RESUMO

Erythema nodosum leprosum is a type 3 hypersensitivity reaction that often presents with transient eruptions of red papules, plaques, and nodules. A 52-year-old female presented with multiple joint pain that was being treated as rheumatoid arthritis (RA), but through clinical examination, she was found to have Hansen's disease with a type 2 reaction. Hence, the importance of a thorough clinical examination is a must for the timely and correct diagnosis of patients suffering from Hansen's disease.

2.
Cureus ; 16(3): e56600, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38646262

RESUMO

Reticulate pigmentary disorders are autosomal dominant pigmentary disorders caused by abnormalities in the keratin 5 and keratin 14 genes. Here, we report three cases of reticulate hyperpigmentation disorders with clinical overlaps of the reticulate acropigmentation of Kitamura, Dowling-Degos disease (DDD), and dyschromatosis symmetrica hereditaria (DSH), all three having limited treatment options.

3.
Semin Neurol ; 43(3): 480-492, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37517406

RESUMO

Unruptured intracranial aneurysms are often discovered incidentally on noninvasive imaging. As use of noninvasive imaging has increased, our understanding of the presumed prevalence of intracranial aneurysms in adults has increased. Incidentally found aneurysms are often asymptomatic; however, they can rarely rupture and cause life-threatening illness. Elective treatment of intracranial aneurysms carries risks which need to be considered along with patient-specific factors (e.g., anatomy, medical comorbidities, personal preferences). In this article, we review the natural history, risk factors for cerebral aneurysm formation and rupture, evidence for medical management, and the safety profile and efficacy of available endovascular treatment options.


Assuntos
Aneurisma Intracraniano , Adulto , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/epidemiologia , Prevalência , Fatores de Risco
4.
Indian J Ophthalmol ; 69(9): 2437-2440, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34427239

RESUMO

PURPOSE: Alcohol delamination of the corneal epithelium (ADCE) is a therapeutic option for patients with recurrent corneal erosion (RCE) who do not respond to nonsurgical management of lubricants and extended wear contact lens. The aim of the study is to report on three-year efficacy and safety of ADCE for RCE of traumatic etiology. METHODS: This is a retrospective review of consecutive patients who underwent ADCE for traumatic RCE in a local hospital between January 2010 and January 2020. The outcomes at a 3-year follow-up review are included. Nonsurgical therapy used; intra- and postoperative complications were recorded. ADCE was only offered to those who remained symptomatic despite maximum topical lubrications and/or extended wear contact lens. Success was defined as the absence of recurrence of corneal erosion. RESULTS: Twenty-six eyes of 26 patients with RCE caused by trauma underwent ADCE. The mean age of patients was 39 years. The follow-up period was a minimum of 36 months. Three eyes (11.5%) had recurrence of corneal erosion after ADCE at the 3-year follow-up. Recurrence was noted at months 2, 23, and 36 postoperatively in these patients. All patients reported significant improvement in symptoms associated with recurrent erosion. Ten eyes (38.5%) stopped all topical lubricants postoperatively. No intra- or postoperative complications were noted in our study. CONCLUSION: This study documents the long-term safety and efficacy of alcohol delamination of corneal epithelium at 3 years for patients with RCE of traumatic origin.


Assuntos
Distrofias Hereditárias da Córnea , Úlcera da Córnea , Epitélio Corneano , Adulto , Humanos , Recidiva , Estudos Retrospectivos
5.
Indian J Ophthalmol ; 69(5): 1052-1060, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33913831

RESUMO

The incidence of leishmaniasis is reported to be up to 1 million per year. To date, there has been no comprehensive review describing the diversity of clinical presentations of ocular leishmaniasis (OL) and its treatment. This systematic review aims to address this knowledge gap and provide a summary of the clinical presentation, natural course, and treatment options for OL. Our study identified a total of 57 published articles as describing cases of OL involving: adnexa (n = 26), orbit (n = 1), retina (n = 7), uvea (n = 18) and cornea (n = 6). Though well described and easily treated, palpebral leishmaniasis is often misdiagnosed and may lead to chronic issues if untreated. The retinal manifestations of Leishmaniasis consist of self-resolving hemorrhages secondary to thrombocytopenia. Two main uveitis etiologies have been identified: uveitis in the context of active Leishmanial infection (associated with immunosuppression) and uveitis occurring as an immune reconstitution syndrome. Corneal involvement in most geographic areas generally follows an aggressive course, most often ending in corneal perforation if left untreated. In the Americas, a chronic indolent interstitial keratitis may also occur. Topical steroids are of little use in keratitis (systemic antileishmanials being the cornerstone of treatment). However, these are essential in cases of uveitis, with or without concomitant systemic antileishmanial therapy. In conclusion, though ocular involvement in Leishmaniasis is rare, severe sight-threatening consequences follow if left untreated. Early diagnosis, enthusiastic follow-up and aggressive treatment are essential for good outcomes.


Assuntos
Perfuração da Córnea , Ceratite , Leishmaniose , Uveíte , Córnea , Humanos
6.
Arch Biochem Biophys ; 695: 108620, 2020 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-33038311

RESUMO

Potential health benefits of consuming tea are thought to include anti-inflammatory actions of its constituent flavonoids including catechins, which are well-recognized antioxidants. We analyzed and discovered a novel mechanism by which epigallocatechin gallate (EGCG), the most abundant polyphenol in tea and a putative health-promoting constituent, inhibits activation of the nuclear transcription factor NF-κB, which mediates inflammatory responses to cytokines and other agents. We found that EGCG inhibits NF-κB-p65 transcriptional activity, by preventing NF-κB-p65 binding to κBs in normal human bronchial epithelial cells. We also analyzed the chemical mechanism by which EGCG binds directly to NF-κB-p65, and found that it involves covalent reaction via enones within EGCG ring structures, as the oxidizer diamide, which prevents 1, 4-addition reactions, blocked adduct-forming reaction of biotinylated EGCG with NF-κB-p65. Such blockade was inhibited by competing unlabeled EGCG. Furthermore, such covalent binding reflected irreversible reaction of EGCG with sulfhydryls of NF-κB-p65, as it was inhibited by glutathione but not reversible by it. We identified the reactive sulfhydryl moiety as that of cysteine, as S-carboxymethylation to block cysteine sulfhydryls prevented NF-κB-p65-Cys-alkylation reaction with EGCG. We also tested if EGCG can inhibit NF-κB-p65 binding to DNA within the nucleus, after its phosphorylation and translocation (activation). EGCG did not alter intranuclear phosphorylation levels of NF-κB-p65, but strongly repressed DNA-binding ability of activated NF-κB-p65, indicating that EGCG inhibits NF-κB-p65 DNA binding activity even without altering NF-κB-p65 phosphorylation or expression. These findings thus reveal a novel mechanism by which EGCG inhibits transcriptional activity of NF-κB-p65, that may potentially contribute to anti-inflammatory and health-promoting effects of EGCG and consumption of tea.


Assuntos
Brônquios/metabolismo , Catequina/análogos & derivados , Células Epiteliais/metabolismo , Fator de Transcrição RelA/metabolismo , Ativação Transcricional/efeitos dos fármacos , Catequina/química , Catequina/farmacologia , Linhagem Celular , Humanos , Fosforilação/efeitos dos fármacos , Chá/química
7.
Life Sci ; 259: 118260, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32795541

RESUMO

Cigarette smoke (CS), the major risk factor of chronic obstructive pulmonary disease (COPD), contains numerous free radicals that can cause oxidative stress and exaggerated inflammatory responses in the respiratory system. Lipid peroxidation which is oxidative degradation of polyunsaturated fatty acids and results in cell damage has also been associated with COPD pathogenesis. Increased levels of lipid peroxidation as well as its end product 4-hydroxynonenal have indeed been detected in COPD patients. Additionally, reactive oxygen species such as those contained in CS can activate nuclear factor-κB signaling pathway, initiating cascades of proinflammatory mediator expression. As emerging evidence attests to the antioxidative and anti-inflammatory properties of tea catechins, we sought to determine whether epigallocatechin gallate, the most abundant tea catechin, can provide protection against oxidative stress, lipid peroxidation, and inflammatory responses caused by CS. We found that EGCG treatment blocked cigarette smoke extract (CSE)-induced oxidative stress as indicated by decreased production and accumulation of reactive oxygen species in airway epithelial cells (AECs). Likewise, lipid peroxidation in CSE-stimulated AECs was suppressed by EGCG. Our findings further suggest that EGCG sequestered 4-hydroxynonenal and interfered with its protein adduct formation. Lastly, we show that EGCG inhibited nuclear factor-κB activation and the downstream expression of proinflammatory mediators. In summary, our study describing the antioxidative and anti-inflammatory effects of EGCG in CSE-exposed AECs provide valuable information about the therapeutic potential of this tea catechin for COPD.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Catequina/análogos & derivados , Fumar Cigarros/tratamento farmacológico , Aldeídos/farmacologia , Células Epiteliais Alveolares/metabolismo , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Brônquios/metabolismo , Catequina/metabolismo , Catequina/farmacologia , Linhagem Celular , Fumar Cigarros/efeitos adversos , Fumar Cigarros/fisiopatologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Inflamação/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , NF-kappa B/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Alvéolos Pulmonares/metabolismo , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Espécies Reativas de Oxigênio , Transdução de Sinais/efeitos dos fármacos , Fumaça/efeitos adversos , Fumar/efeitos adversos
8.
Life Sci ; 258: 118136, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32726662

RESUMO

The endothelium is a critical regulator of vascular homeostasis, controlling vascular tone and permeability as well as interactions of leukocytes and platelets with blood vessel walls. Consequently, endothelial dysfunction featuring inflammation and reduced vasodilation are considered central to cardiovascular disease (CVD) pathogenesis and have become a therapeutic area of focus. Type II endothelial cell (EC) activation by stress-related stimuli such as tumor necrosis factor-α (TNF-α) initiates the nuclear factor-κB (NF-κB) signaling pathway, a master regulator of inflammatory responses. Because dysregulated NF-κB signaling has been tightly linked to several CVDs, EC-specific inhibition of NF-κB represents an attractive pharmacological strategy. As accumulating evidence highlights the clinical benefits of tea catechin for multiple diseases including CVDs, we sought to determine whether the tea catechin epigallocatechin gallate (EGCG) that displays antioxidative, anti-inflammatory, hypolipidemic, anti-thrombogenic, and anti-hypertensive properties offers protection against CVDs by suppressing the canonical NF-κB pathway. Our findings indicate that EGCG downregulates multiple components of the TNF-α-induced NF-κB signaling pathway and thereby reduces the consequent increase in inflammatory gene transcription and protein expression. Furthermore, EGCG blocked type II EC activation, evidenced by diminished EC leakage and monocyte adhesion in EGCG-treated cells. In summary, our study advances knowledge of EGCG's anti-inflammatory effects on the NF-κB pathway and hence its benefits on endothelial health, supporting its therapeutic potential for CVDs.


Assuntos
Catequina/análogos & derivados , Vasos Coronários/patologia , Células Endoteliais/patologia , Inflamação/tratamento farmacológico , Catequina/farmacologia , Catequina/uso terapêutico , Adesão Celular/efeitos dos fármacos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Inflamação/genética , Inflamação/patologia , Mediadores da Inflamação/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/patologia , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
9.
Clin Sci (Lond) ; 134(9): 1063-1079, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32369100

RESUMO

Asthma is a chronic disease of the airways that has long been viewed predominately as an inflammatory condition. Accordingly, current therapeutic interventions focus primarily on resolving inflammation. However, the mainstay of asthma therapy neither fully improves lung function nor prevents disease exacerbations, suggesting involvement of other factors. An emerging concept now holds that airway remodeling, another major pathological feature of asthma, is as important as inflammation in asthma pathogenesis. Structural changes associated with asthma include disrupted epithelial integrity, subepithelial fibrosis, goblet cell hyperplasia/metaplasia, smooth muscle hypertrophy/hyperplasia, and enhanced vascularity. These alterations are hypothesized to contribute to airway hyperresponsiveness, airway obstruction, airflow limitation, and progressive decline of lung function in asthmatic individuals. Consequently, targeting inflammation alone does not suffice to provide optimal clinical benefits. Here we review asthmatic airway remodeling, focusing on airway epithelium, which is critical to maintaining a healthy respiratory system, and is the primary defense against inhaled irritants. In asthma, airway epithelium is both a mediator and target of inflammation, manifesting remodeling and resulting obstruction among its downstream effects. We also highlight the potential benefits of therapeutically targeting airway structural alterations. Since pathological tissue remodeling is likewise observed in other injury- and inflammation-prone tissues and organs, our discussion may have implications beyond asthma and lung disease.


Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Antiasmáticos/farmacologia , Asma/fisiopatologia , Inflamação/tratamento farmacológico , Animais , Asma/tratamento farmacológico , Epitélio/efeitos dos fármacos , Humanos , Inflamação/fisiopatologia , Pulmão/efeitos dos fármacos , Pulmão/fisiopatologia
10.
Cureus ; 12(4): e7505, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32373408

RESUMO

Primitive neuroectodermal tumors (PNET, previously referred to as peripheral neuroepithelioma) are rare malignant tumors with various degrees of differentiation belonging to the Ewing's family of sarcomas. They are classified as round cell tumors arising from soft tissues. In rare instances, PNETs may arise from solid organs containing neuroendocrine cells of kidney, bladder, heart, lungs, parotid glands and pancreas. Most cases occur in the second decade of life with a slight preponderance in males. PNET of the pancreas is an aggressive tumor with multiple recurrences and a relatively poor prognosis. These tumors should be considered in the differential diagnosis, especially in a diagnosed pancreatic tumor in individuals less than 35 years of age. Due to the nature of the tumor, surgery with subsequent chemoradiation are widely accepted modalities despite the poor prognosis. In this article, we review 25 cases of extraosseous Ewing's sarcoma (ES) of the pancreas which to the best of our knowledge, enlists most cases reported in the literature thus far.

11.
Artigo em Inglês | MEDLINE | ID: mdl-32021151

RESUMO

Background: Glucocorticoids are commonly prescribed to treat inflammation of the respiratory system; however, they are mostly ineffective for controlling chronic obstructive pulmonary disease (COPD)-associated inflammation. This study aimed to elucidate the molecular mechanisms responsible for such glucocorticoid inefficacy in COPD, which may be instrumental to providing better patient outcomes. Roflumilast is a selective phosphodiesterase-4 (PDE4) inhibitor with anti-inflammatory properties in severe COPD patients who have a history of exacerbations. Roflumilast has a suggested ability to mitigate glucocorticoid resistance, but the mechanism is unknown. Methods: To understand the mechanism that mediates roflumilast-induced restoration of glucocorticoid sensitivity in COPD, we tested the role of glucocorticoid receptor α (GRα). Roflumilast's effects on GRα expression and transcriptional activity were assessed in bronchial epithelial cells from COPD patients. Results: We found that both GRα expression and activity are downregulated in bronchial epithelial cells from COPD patients and that roflumilast stimulates both GRα mRNA synthesis and GRα's transcriptional activity in COPD bronchial epithelial cells. We also demonstrate that roflumilast enhances dexamethasone's ability to suppress pro-inflammatory mediator production, in a GRα-dependent manner. Discussion: Our findings highlight the significance of roflumilast-induced GRα upregulation for COPD therapeutic strategies by revealing that roflumilast restores glucocorticoid sensitivity by sustaining GRα expression.


Assuntos
Aminopiridinas/farmacologia , Benzamidas/farmacologia , Dexametasona/farmacologia , Células Epiteliais/efeitos dos fármacos , Glucocorticoides/farmacologia , Pulmão/efeitos dos fármacos , Inibidores da Fosfodiesterase 4/farmacologia , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Receptores de Glucocorticoides/agonistas , Células Cultivadas , Ciclopropanos/farmacologia , Resistência a Medicamentos , Células Epiteliais/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Interleucina-8/metabolismo , Pulmão/metabolismo , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
12.
PLoS One ; 15(2): e0229256, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084204

RESUMO

Cigarette smoke (CS) contains multiple gaseous and particulate materials that can cause lung inflammation, and smoking is the major cause of chronic obstructive pulmonary disease (COPD). We sought to determine the mechanisms of how CS triggers lung inflammation. Nur77, a nuclear hormone receptor belonging to the immediate-early response gene family, controls inflammatory responses, mainly by suppressing the NF-κB signaling pathway. Because it is unknown if Nur77's anti-inflammatory role modulates COPD, we assessed if and how Nur77 expression and activity are altered in CS-induced airway inflammation. In lung tissues and bronchial epithelial cells from COPD patients, we found Nur77 was downregulated. In a murine model of CS-induced airway inflammation, CS promoted lung inflammation and also reduced Nur77 activity in wild type (WT) mice, whereas lungs of Nur77-deficient mice showed exaggerated CS-induced inflammatory responses. Our findings in in vitro studies of human airway epithelial cells complemented those in vivo data in mice, together showing that CS induced threonine-phosphorylation of Nur77, which is known to interfere with its anti-inflammatory functions. In summary, our findings point to Nur77 as an important regulator of CS-induced inflammatory responses and support the potential benefits of Nur77 activation for COPD treatment.


Assuntos
Regulação para Baixo/efeitos dos fármacos , Nicotiana/química , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , Doença Pulmonar Obstrutiva Crônica/genética , Fumaça/efeitos adversos , Animais , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Humanos , Inflamação/genética , Pulmão/patologia , Camundongos , Fosforilação/efeitos dos fármacos , Doença Pulmonar Obstrutiva Crônica/patologia , Treonina/metabolismo
13.
Biochem J ; 476(19): 2757-2767, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31492735

RESUMO

Nur77 is a transcription factor belonging to the NR4A subfamily of nuclear hormone receptors. Upon induction, Nur77 modulates the expression of its target genes and controls a variety of biological and pathophysiological processes. Prior research that revealed a structurally atypical ligand-binding domain (LBD) and failed to locate an endogenous ligand had led to a classification of Nur77 as an orphan receptor. However, several more recent studies indicate that small synthetic molecules and unsaturated fatty acids can bind to Nur77. Discovery of additional endogenous ligands will facilitate our understanding of the receptor's functions and regulatory mechanisms. Our data have identified prostaglandin A2 (PGA2), a cyclopentenone prostaglandin (PG), as such a ligand. Cyclopentenone PGs exert their biological effects primarily by forming protein adducts via the characteristic electrophilic ß-carbon(s) located in their cyclopentenone rings. Our data show that PGA2 induces Nur77 transcriptional activity by forming a covalent adduct between its endocyclic ß-carbon, C9, and Cys566 in the receptor's LBD. The importance of this endocyclic ß-carbon was substantiated by the failure of PGs without such electrophilic properties to react with Nur77. Calculated chemical properties and data from reactive molecular dynamic simulations, intrinsic reaction co-ordinate modeling, and covalent molecular docking also corroborate the selectivity of PGA2's C9 ß-carbon towards Nur77's Cys. In summary, our molecular, chemical, and structural characterization of the PGA2-Nur77 interaction provides the first evidence that PGA2 is an endogenous Nur77 agonist.


Assuntos
Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/agonistas , Prostaglandinas A/química , Prostaglandinas A/fisiologia , Linhagem Celular , Humanos , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Prostaglandinas A/metabolismo , Ligação Proteica , Domínios Proteicos
15.
Am J Pathol ; 189(3): 482-491, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30414411

RESUMO

The transcription factor Nur77 belongs to the NR4A subfamily of nuclear hormone receptors. It features an atypical ligand-binding site that precludes canonical ligand binding, leading to the designation orphan nuclear receptor. However, recent studies show that small molecules can interact with the receptor and modulate its activity by inducing a conformational change in the Nur77 ligand-binding site. Nur77 expression and activation are rapidly induced by various physiological and pathologic stimuli. Once expressed, Nur77 initiates transcriptional activity and modulates expression of its target genes. Both in vitro and in vivo evidence shows that Nur77 dampens the immune response to proinflammatory stimuli, such as tumor necrosis factor-α, Toll-like receptor ligands, and oxidized lipids, primarily by suppressing NF-κB signaling. Although studies focusing on Nur77's role in lung pathophysiology are currently incomplete, available data support its involvement in the pathogenesis of lung diseases, including asthma, acute lung injury, and pulmonary fibrosis, and thus suggest a therapeutic potential for Nur77 activation in these diseases. This review addresses the mechanisms that control Nur77 as well as its known roles in inflammation-related lung diseases. Evidence regarding the therapeutic potential of Nur77-targeting molecules will also be presented. Although current knowledge is limited, additional research followed by clinical studies may firmly identify Nur77 as a pharmacologic target for inflammation-related lung diseases.


Assuntos
Pneumopatias/metabolismo , Pulmão/metabolismo , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares/metabolismo , Transdução de Sinais , Transcrição Gênica , Animais , Humanos , Inflamação/metabolismo , Inflamação/patologia , Pulmão/patologia , Pneumopatias/patologia , Pneumopatias/terapia , NF-kappa B/biossíntese , Receptores Toll-Like/biossíntese , Fator de Necrose Tumoral alfa/biossíntese
16.
ACS Chem Biol ; 13(12): 3269-3278, 2018 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-30398845

RESUMO

PPARδ belongs to the peroxisome proliferator-activated receptor (PPAR) family of nuclear receptors. Upon activation by an agonist, PPARδ controls a variety of physiological processes via regulation of its target genes. 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is a cyclopentenone prostaglandin that features an electrophilic, α,ß-unsaturated ketone (an enone) in the cyclopentenone ring. Many of 15d-PGJ2's biological effects result from covalent interaction between C9 and the thiol group of a catalytic cysteine (Cys) in target proteins. In this study, we investigated whether 15d-PGJ2 activates PPARδ by forming a covalent adduct. Our data show that 15d-PGJ2 activates PPARδ's transcriptional activity through formation of a covalent adduct between its endocyclic enone at C9 and Cys249 in the receptor's ligand-binding domain. As expected, no adduct formation was seen following a Cys-to-Ser mutation at residue 249 (C249S) of PPARδ or with a PGD2/PGJ2 analogue that lacks the electrophilic C9. Furthermore, the PPARδ C249S mutation weakened induction of the receptor's DNA binding activity by 15d-PGJ2, which highlights the biological significance of our findings. Calculated chemical properties as well as data from molecular orbital calculations, reactive molecular dynamics simulations, and intrinsic reaction coordinate modeling also supported the selectivity of 15d-PGJ2's C9 toward PPARδ's Cys thiol. In summary, our results provide the molecular, chemical, and structural basis of 15d-PGJ2-mediated PPARδ activation, designating 15d-PGJ2 as the first covalent PPARδ ligand to be identified.


Assuntos
PPAR delta/agonistas , PPAR delta/metabolismo , Prostaglandina D2/análogos & derivados , Alquilação , Linhagem Celular , Cisteína/química , Teoria da Densidade Funcional , Humanos , Ligantes , Modelos Químicos , Simulação de Dinâmica Molecular , Mutação , PPAR delta/química , PPAR delta/genética , Prostaglandina D2/química , Prostaglandina D2/metabolismo , Prostaglandina D2/farmacologia , Ligação Proteica , Domínios Proteicos
17.
J Immunol ; 201(6): 1775-1783, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30061200

RESUMO

Airway epithelial cells (AECs) orchestrate inflammatory responses to airborne irritants that enter the respiratory system. A viscous mucus layer produced by goblet cells in the airway epithelium also contributes to a physiological defense mechanism through the physical and chemical barriers it provides. Dysregulation or impairment in these functions has been implicated as a cause of the chronic inflammation and tissue remodeling that constitute major pathological features of asthma. In particular, mucus hypersecretion leading to airway obstruction and impaired pulmonary function is associated with morbidity and mortality in asthma patients. Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-activated transcription factor involved in a variety of cellular processes. Accumulating evidence indicates that PPARγ agonists antagonize exaggerated inflammatory responses, yet PPARγ's precise role in airway remodeling/mucus hypersecretion has yet to be defined. In this study, we created an AEC-specific PPARγ (AEC-PPARγ) deletion to investigate PPARγ's functions in a murine model of allergic airway disease. AEC-PPARγ deficiency exaggerated airway hyperresponsiveness, inflammation, cytokine expression, and tissue remodeling. We also found that PPARγ directly bound to a PPAR response element found in MUC5AC and repressed gene expression. Likewise, PPARγ regulated mucin and inflammatory factors in primary human bronchial epithelial cells. In light of the current standard therapies' limited and inadequate direct effect on airway mucus hypersecretion, our study showing AEC-PPARγ's role as a transcriptional repressor of MUC5AC highlights this receptor's potential as a pharmacological target for asthma.


Assuntos
Asma/imunologia , Células Epiteliais/imunologia , Regulação da Expressão Gênica/imunologia , Mucina-5AC/imunologia , PPAR gama/imunologia , Mucosa Respiratória/imunologia , Animais , Asma/genética , Asma/patologia , Células Cultivadas , Células Epiteliais/patologia , Feminino , Humanos , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Masculino , Camundongos , Camundongos Knockout , Mucina-5AC/genética , PPAR gama/genética , Mucosa Respiratória/patologia , Elementos de Resposta/imunologia
18.
Free Radic Biol Med ; 126: 350-357, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30118830

RESUMO

Cigarette smoke, a source of numerous oxidants, produces oxidative stress and exaggerated inflammatory responses that lead to irreversible lung tissue damage. It is the single, most significant risk factor for chronic obstructive pulmonary disease (COPD). Although an intrinsic defense system that includes both enzymatic and non-enzymatic modulators exists to protect lung tissues against oxidative stress, impairment of these protective mechanisms has been demonstrated in smokers and COPD patients. The antioxidant enzyme GSH peroxidase (GPx) is an important part of this intrinsic defense system. Although cigarette smoke has been shown to downregulate its expression and activity, the underlying mechanism is not known. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear hormone receptor with antioxidant effects. PPARγ activation has demonstrated protective effects against cigarette smoke-induced oxidative stress and inflammation. Molecular mechanisms for PPARγ's antioxidant function likewise remain to be elucidated. This study explored the link between PPARγ and GPx3 and found a positive association in cigarette smoke extract (CSE)-exposed human bronchial epithelial cells. Moreover, we provide evidence that identifies GPx3 as a PPARγ transcriptional target. Attenuation of antioxidant effects in the absence of GPx3 highlights the antioxidant's prominent role in mediating PPARγ's function. We also demonstrate that ligand-mediated PPARγ activation blocks CSE-induced reactive oxygen species and hydrogen peroxide production via upregulation of GPx3. In summary, our findings describing the molecular mechanisms involving GPx3 and PPARγ in CSE-induced oxidative stress and inflammation may provide valuable information for the development of more effective therapeutics for COPD.


Assuntos
Fumar Cigarros/efeitos adversos , Glutationa Peroxidase/genética , PPAR gama/genética , Doença Pulmonar Obstrutiva Crônica/genética , Antioxidantes/metabolismo , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Linhagem Celular , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Glutationa Peroxidase/metabolismo , Humanos , Estresse Oxidativo/genética , PPAR gama/metabolismo , Doença Pulmonar Obstrutiva Crônica/patologia , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fumar/efeitos adversos
19.
Eye (Lond) ; 32(11): 1752-1759, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30013158

RESUMO

AIMS: To evaluate retreatment rates, visual and anatomical outcomes at 1-year postnatal age in infants treated for retinopathy of prematurity (ROP) METHODS: Longitudinal national surveillance study of infants treated for ROP in the United Kingdom between December 2013 and December 2014, supported by the British Ophthalmic Surveillance Unit. Here we report retreatment rates, anatomical, visual and refractive outcomes at 1-year follow-up. RESULTS: One-year follow-up forms were completed for 168 children of the original cohort of 327 (51.4%). Twenty-two had at least one retreatment: 17/153 right eyes (REs, 11.1%) after initial diode laser, and 5/14 REs (35.7%) after initial injection of anti-vascular endothelial growth factor (VEGF) antibody. Median (interquartile range) RE best-corrected visual acuity was 0.6 (0.4-1.0) (n = 46 REs), and median acuity both eyes open 0.4 (0.3-0.7) logMAR (n = 89). Median spherical equivalent (RE) was 0.44 (-1.3 to 1.3) dioptre (D) (n = 116). Median astigmatism (RE) was 0.5 (0-1.0) D (n = 111), and median anisometropia 0.125 (0-0.75) D (n = 116). Twenty-four children (20.5%) had been prescribed glasses. Sight impairment certification eligibility information was available for 131 children: 11 (8.4%) were eligible to be certified as sight impaired, and 5 (3.8%) as severely sight impaired. CONCLUSIONS: Retreatment rates are in line with previous reports, and appear higher after initial anti-VEGF antibody than after initial diode laser. Refractive outcomes are in line with previous studies, with a trend towards early emmetropia and myopia following diode laser, particularly in more severe ROP.


Assuntos
Retinopatia da Prematuridade/terapia , Retratamento/estatística & dados numéricos , Inibidores da Angiogênese/uso terapêutico , Astigmatismo/fisiopatologia , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Fotocoagulação a Laser , Masculino , Refração Ocular/fisiologia , Retina/patologia , Retinopatia da Prematuridade/patologia , Retinopatia da Prematuridade/fisiopatologia , Reino Unido , Acuidade Visual/fisiologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-29450204

RESUMO

Asthma affects approximately 300 million people worldwide, significantly impacting quality of life and healthcare costs. While current therapies are effective in controlling many patients' symptoms, a large number continue to experience exacerbations or treatment-related adverse effects. Alternative therapies are thus urgently needed. Accumulating evidence has shown that the peroxisome proliferator-activated receptor (PPAR) family of nuclear hormone receptors, comprising PPARα, PPARß/δ, and PPARγ, is involved in asthma pathogenesis and that ligand-induced activation of these receptors suppresses asthma pathology. PPAR agonists exert their anti-inflammatory effects primarily by suppressing pro-inflammatory mediators and antagonizing the pro-inflammatory functions of various cell types relevant to asthma pathophysiology. Experimental findings strongly support the potential clinical benefits of PPAR agonists in the treatment of asthma. We review current literature, highlighting PPARs' key role in asthma pathogenesis and their agonists' therapeutic potential. With additional research and rigorous clinical studies, PPARs may become attractive therapeutic targets in this disease.

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