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1.
J Cell Sci ; 135(5)2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34080635

RESUMO

Despite the recognized significance of reversible protein lipidation (S-acylation) for T cell receptor signal transduction, the enzymatic control of this post-translational modification in T cells remains poorly understood. Here, we demonstrate that DHHC21 (also known as ZDHHC21), a member of the DHHC family of mammalian protein acyltransferases, mediates T cell receptor-induced S-acylation of proximal T cell signaling proteins. Using Zdhhc21dep mice, which express a functionally deficient version of DHHC21, we show that DHHC21 is a Ca2+/calmodulin-dependent enzyme critical for activation of naïve CD4+ T cells in response to T cell receptor stimulation. We find that disruption of the Ca2+/calmodulin-binding domain of DHHC21 does not affect thymic T cell development but prevents differentiation of peripheral CD4+ T cells into Th1, Th2 and Th17 effector T helper lineages. Our findings identify DHHC21 as an essential component of the T cell receptor signaling machinery and define a new role for protein acyltransferases in regulation of T cell-mediated immunity.

2.
Sci Rep ; 11(1): 6466, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33742073

RESUMO

Smoking is one of the leading risk factors for cardiovascular diseases, including ischemic heart disease and hypertension. However, in acute myocardial infarction (AMI) patients, smoking has been associated with better clinical outcomes, a phenomenon termed the "smoker's paradox." Given the known detrimental effects of smoking on the cardiovascular system, it has been proposed that the beneficial effect of smoking on outcomes is due to age differences between smokers and non-smokers and is therefore a smoker's pseudoparadox. The aim of this study was to evaluate the association between smoking status and clinical outcomes in ST-segment elevation (STEMI) and non-STEMI (NSTEMI) patients treated by percutaneous coronary intervention (PCI), using a national multi-ethnic Asian registry. In unadjusted analyses, current smokers had better clinical outcomes following STEMI and NSTEMI. However, after adjusting for age, the protective effect of smoking was lost, confirming a smoker's pseudoparadox. Interestingly, although current smokers had increased risk for recurrent MI within 1 year after PCI in both STEMI and NSTEMI patients, there was no increase in mortality. In summary, we confirm the existence of a smoker's pseudoparadox in a multi-ethnic Asian cohort of STEMI and NSTEMI patients and report increased risk of recurrent MI, but not mortality, in smokers.

3.
J Biol Chem ; 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082140

RESUMO

Evolving evidence suggests nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness (AHR). We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (ET-1), and collagen (COL1A1, and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary lung fibroblasts (LFs) exposed to nicotine (50 µg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 µg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist, rosiglitazone. Compared to unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo.  Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, while treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3'UTR and also abrogated nicotine-induced increases in NGF, FN1, and ET-1 in LFs. Similarly, rosiglitazone increased miR-98 and reversed nicotine-induced increases in NGF, FN1, and ET-1. Taken together, these findings demonstrate that nicotine-induced increases in NGF and other markers of airway remodeling are negatively regulated by miR-98.

4.
Am J Respir Cell Mol Biol ; 63(5): 637-651, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32672471

RESUMO

Cigarette smoke (CS) exposure increases the risk for acute respiratory distress syndrome in humans and promotes alveolar-capillary barrier permeability and acute lung injury in animal models. However, the underlying mechanisms are not well understood. Mitochondrial fusion and fission are essential for mitochondrial homeostasis in health and disease. In this study, we hypothesized that CS caused endothelial injury via an imbalance of mitochondrial fusion and fission and resultant mitochondrial oxidative stress and dysfunction. We noted that CS altered mitochondrial morphology by shortening mitochondrial networks and causing perinuclear accumulation of damaged mitochondria in primary rat lung microvascular endothelial cells. We also found that CS increased mitochondrial fission likely by decreasing Drp1-S637 and increasing FIS1, Drp1-S616 phosphorylation, mitochondrial translocation, and tetramerization and reduced mitochondrial fusion likely by decreasing Mfn2 in lung microvascular endothelial cells and mouse lungs. CS also caused aberrant mitophagy, increased mitochondrial oxidative stress, and reduced mitochondrial respiration. An inhibitor of mitochondrial fission and a mitochondria-specific antioxidant prevented CS-induced increased endothelial barrier dysfunction and apoptosis. Our data suggest that excessive mitochondrial fission and resultant oxidative stress are essential mediators of CS-induced endothelial injury and that inhibition of mitochondrial fission and mitochondria-specific antioxidants may be useful therapeutic strategies for CS-induced endothelial injury and associated pulmonary diseases.

5.
Pulm Circ ; 10(2): 2045894020924994, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32523687

RESUMO

Adenosine is a potent signaling molecule that has paradoxical effects on lung diseases. We have previously demonstrated that sustained adenosine exposure by inhibition of adenosine degradation impairs lung endothelial barrier integrity and causes intrinsic apoptosis through equilibrative nucleoside transporter1/2-mediated intracellular adenosine signaling. In this study, we further demonstrated that sustained adenosine exposure increased mitochondrial reactive oxygen species and reduced mitochondrial respiration via equilibrative nucleoside transporter1/2, but not via adenosine receptor-mediated signaling. We have previously shown that sustained adenosine exposure activates p38 and c-Jun N-terminal kinases in mitochondria. Here, we show that activation of p38 and JNK partially contributed to sustained adenosine-induced mitochondrial reactive oxygen species production. We also found that sustained adenosine exposure promoted mitochondrial fission and increased mitophagy. Finally, mitochondria-targeted antioxidants prevented sustained adenosine exposure-induced mitochondrial fission and improved cell survival. Our results suggest that inhibition of equilibrative nucleoside transporter1/2 and mitochondria-targeted antioxidants may be potential therapeutic approaches for lung diseases associated with sustained elevated adenosine.

6.
J Exp Med ; 217(2)2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-31757866

RESUMO

Systemic sclerosis (SSc; scleroderma) is a multisystem fibrotic disease. The mammalian cleavage factor I 25-kD subunit (CFIm25; encoded by NUDT21) is a key regulator of alternative polyadenylation, and its depletion causes predominantly 3'UTR shortening through loss of stimulation of distal polyadenylation sites. A shortened 3'UTR will often lack microRNA target sites, resulting in increased mRNA translation due to evasion of microRNA-mediated repression. Herein, we report that CFlm25 is downregulated in SSc skin, primary dermal fibroblasts, and two murine models of dermal fibrosis. Knockdown of CFIm25 in normal skin fibroblasts is sufficient to promote the 3'UTR shortening of key TGFß-regulated fibrotic genes and enhance their protein expression. Moreover, several of these fibrotic transcripts show 3'UTR shortening in SSc skin. Finally, mice with CFIm25 deletion in fibroblasts show exaggerated skin fibrosis upon bleomycin treatment, and CFIm25 restoration attenuates bleomycin-induced skin fibrosis. Overall, our data link this novel RNA-processing mechanism to dermal fibrosis and SSc pathogenesis.


Assuntos
Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Regulação para Baixo/genética , Poliadenilação/genética , Escleroderma Sistêmico/metabolismo , Regiões 3' não Traduzidas/genética , Animais , Bleomicina/farmacologia , Células Cultivadas , Fator de Especificidade de Clivagem e Poliadenilação/genética , Modelos Animais de Doenças , Feminino , Fibroblastos/metabolismo , Fibrose , Técnicas de Silenciamento de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Escleroderma Sistêmico/induzido quimicamente , Escleroderma Sistêmico/patologia , Pele/patologia , Transfecção
7.
J Biol Chem ; 294(43): 15781-15794, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31488543

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by the pathological remodeling of air sacs as a result of excessive accumulation of extracellular matrix (ECM) proteins, but the mechanism governing the robust protein expression is poorly understood. Our recent findings demonstrate that alternative polyadenylation (APA) caused by NUDT21 reduction is important for the increased expression of fibrotic mediators and ECM proteins in lung fibroblasts by shortening the 3'-untranslated regions (3'-UTRs) of mRNAs and stabilizing their transcripts, therefore activating pathological signaling pathways. Despite the importance of NUDT21 reduction in the regulation of fibrosis, the underlying mechanisms for the depletion are unknown. We demonstrate here that NUDT21 is depleted by TGFß1. We found that miR203, which is increased in IPF, was induced by TGFß1 to target the NUDT21 3'-UTR, thus depleting NUDT21 in human and mouse lung fibroblasts. TGFß1-mediated NUDT21 reduction was attenuated by the miR203 inhibitor antagomiR203 in fibroblasts. TGFß1 transgenic mice revealed that TGFß1 down-regulates NUDT21 in fibroblasts in vivo Furthermore, TGFß1 promoted differential APA of fibrotic genes, including FGF14, RICTOR, TMOD2, and UCP5, in association with increased protein expression. This unique differential APA signature was also observed in IPF fibroblasts. Altogether, our results identified TGFß1 as an APA regulator through NUDT21 depletion amplifying pulmonary fibrosis.


Assuntos
Regiões 3' não Traduzidas/genética , Pulmão/patologia , Fator de Crescimento Transformador beta1/metabolismo , Animais , Células Cultivadas , Fator de Especificidade de Clivagem e Poliadenilação/genética , Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Regulação para Baixo/genética , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Humanos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Poliadenilação/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
8.
Genome Med ; 11(1): 55, 2019 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-31446897

RESUMO

BACKGROUND: Human cancer cell lines are fundamental models for cancer research and therapeutic strategy development. However, there is no characterization of circular RNAs (circRNAs) in a large number of cancer cell lines. METHODS: Here, we apply four circRNA identification algorithms to heuristically characterize the expression landscape of circRNAs across ~ 1000 human cancer cell lines from CCLE polyA-enriched RNA-seq data. By using integrative analysis and experimental approaches, we explore the expression landscape, biogenesis, functional consequences, and drug response of circRNAs across different cancer lineages. RESULTS: We revealed highly lineage-specific expression patterns of circRNAs, suggesting that circRNAs may be powerful diagnostic and/or prognostic markers in cancer treatment. We also identified key genes involved in circRNA biogenesis and confirmed that TGF-ß signaling may promote biogenesis of circRNAs. Strikingly, we showed that clinically actionable genes are more likely to generate circRNAs, potentially due to the enrichment of RNA-binding protein (RBP) binding sites. Among these, circMYC can promote cell proliferation. We observed strong association between the expression of circRNAs and the response to drugs, especially those targeting chromatin histone acetylation. Finally, we developed a user-friendly data portal, CircRNAs in cancer cell lines (CircRiC, https://hanlab.uth.edu/cRic ), to benefit the biomedical research community. CONCLUSIONS: Our study provides the characterization of circRNAs in cancer cell lines and explored the potential mechanism of circRNA biogenesis as well as its therapeutic implications. We also provide a data portal to facilitate the related biomedical researches.


Assuntos
Neoplasias/genética , RNA Circular , Linhagem Celular Tumoral , Biologia Computacional , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Transcriptoma
9.
Exp Mol Med ; 51(6): 1-13, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31221962

RESUMO

Since the discovery of hypoxia-inducible factor (HIF), numerous studies on the hypoxia signaling pathway have been performed. The role of HIF stabilization during hypoxia has been extended from the induction of a single gene erythropoietin to the upregulation of a couple of hundred downstream targets, which demonstrates the complexity and importance of the HIF signaling pathway. Accordingly, HIF and its downstream targets are emerging as novel therapeutic options to treat various organ injuries. In this review, we discuss the current understanding of HIF signaling in four different organ systems, including the heart, lung, liver, and kidney. We also discuss the divergent roles of HIF in acute and chronic disease conditions and their revealed functions. Finally, we introduce some of the efforts that are being performed to translate our current knowledge in hypoxia signaling to clinical medicine.


Assuntos
Cardiopatias/complicações , Hipóxia/complicações , Nefropatias/complicações , Hepatopatias/complicações , Pneumopatias/complicações , Animais , Cardiopatias/metabolismo , Cardiopatias/terapia , Humanos , Hipóxia/metabolismo , Hipóxia/terapia , Fator 1 Induzível por Hipóxia/metabolismo , Nefropatias/metabolismo , Nefropatias/terapia , Hepatopatias/metabolismo , Hepatopatias/terapia , Pneumopatias/metabolismo , Pneumopatias/terapia , Transdução de Sinais
10.
J Clin Invest ; 129(5): 1984-1999, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30830875

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a chronic and deadly disease with a poor prognosis and few treatment options. Pathological remodeling of the extracellular matrix (ECM) by myofibroblasts is a key factor that drives disease pathogenesis, although the underlying mechanisms remain unknown. Alternative polyadenylation (APA) has recently been shown to play a major role in cellular responses to stress by driving the expression of fibrotic factors and ECMs through altering microRNA sensitivity, but a connection to IPF has not been established. Here, we demonstrate that CFIm25, a global regulator of APA, is down-regulated in the lungs of patients with IPF and mice with pulmonary fibrosis, with its expression selectively reduced in alpha-smooth muscle actin (α-SMA) positive fibroblasts. Following the knockdown of CFIm25 in normal human lung fibroblasts, we identified 808 genes with shortened 3'UTRs, including those involved in the transforming growth factor-ß signaling pathway, the Wnt signaling pathway, and cancer pathways. The expression of key pro-fibrotic factors can be suppressed by CFIm25 overexpression in IPF fibroblasts. Finally, we demonstrate that deletion of CFIm25 in fibroblasts or myofibroblast precursors using either the Col1a1 or the Foxd1 promoter enhances pulmonary fibrosis after bleomycin exposure in mice. Taken together, our results identified CFIm25 down-regulation as a novel mechanism to elevate pro-fibrotic gene expression in pulmonary fibrosis.


Assuntos
Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Poliadenilação , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/fisiopatologia , Regiões 3' não Traduzidas , Actinas/metabolismo , Adulto , Idoso , Animais , Bleomicina/farmacologia , Progressão da Doença , Regulação para Baixo , Matriz Extracelular/metabolismo , Feminino , Fibroblastos/metabolismo , Humanos , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Músculo Liso/metabolismo , Miofibroblastos/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo
11.
Blood Adv ; 2(15): 1957-1968, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30097462

RESUMO

Although excessive plasma adenosine is detrimental in sickle cell disease (SCD), the molecular mechanism underlying elevated circulating adenosine remains unclear. Here we report that the activity of soluble CD73, an ectonucleotidase producing extracellular adenosine, was significantly elevated in a murine model of SCD and correlated with increased plasma adenosine. Mouse genetic studies demonstrated that CD73 activity contributes to excessive induction of plasma adenosine and thereby promotes sickling, hemolysis, multiorgan damage, and disease progression. Mechanistically, we showed that erythrocyte adenosine 5'-monophosphate-activated protein kinase (AMPK) was activated both in SCD patients and in the murine model of SCD. AMPK functions downstream of adenosine receptor ADORA2B signaling and contributes to sickling by regulating the production of erythrocyte 2,3-bisphosphoglycerate (2,3-BPG), a negative allosteric regulator of hemoglobin-O2 binding affinity. Preclinically, we reported that treatment of α,ß-methylene adenosine 5'-diphosphate, a potent CD73 specific inhibitor, significantly decreased sickling, hemolysis, multiorgan damage, and disease progression in the murine model of SCD. Taken together, both human and mouse studies reveal a novel molecular mechanism contributing to the pathophysiology of SCD and identify potential therapeutic strategies to treat SCD.


Assuntos
5'-Nucleotidase , Trifosfato de Adenosina/análogos & derivados , Anemia Falciforme , Eritrócitos/enzimologia , 2,3-Difosfoglicerato/metabolismo , 5'-Nucleotidase/antagonistas & inibidores , 5'-Nucleotidase/genética , 5'-Nucleotidase/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/enzimologia , Anemia Falciforme/genética , Anemia Falciforme/patologia , Animais , Eritrócitos/patologia , Feminino , Proteínas Ligadas por GPI/antagonistas & inibidores , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Humanos , Masculino , Camundongos , Camundongos Knockout , Receptor A2B de Adenosina/genética , Receptor A2B de Adenosina/metabolismo
12.
Biochem Biophys Res Commun ; 503(2): 856-862, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-29928883

RESUMO

BACKGROUND: Non-small cell lung cancer (NSCLC) is a life-threatening disease that has a poor prognosis and low survival rate. Cleavage factor Im 25 (CFIm25) is a RNA-binding protein that if down-regulated causes 3'UTR shortening and thus promotes the transcript stability of target genes. It is not clear whether CFIm25 and alternative polyadenylation (APA) play a role during cancer development. The purpose of this study is to explore the role of CFIm25 in lung cancer cell proliferation. METHODS: CFIm25 was knocked down in A549 cells. Western blots were carried out to determine the protein expression of CFIm25, insulin growth factor 1 receptor (IGF1R), CyclinD1 (CCND1) and TP53. Real-time qRT PCR was performed to determine the total transcript levels of CFIm25 targets and the normalized fold changes in their distal PAS (dPAS) usage. Immunofluorescence was carried out to check the expression of CFIm25, IGF1R and CCND1. Cell proliferation over time was determined using the WST-1 reagent. RESULTS: The transcript levels of CCND1 and GSK3ß were significantly increased and the dPAS usage of several oncogenes (IGF1R, CCND1 and GSK3ß) were decreased after CFIm25 knockdown. The protein level of IGF1R was increased, and we detected increased percentage of CCND1 positive cells and cell proliferation over time in CFIm25 knockdown cells. In addition, the mRNA and APA analysis of IGF1R using patient RNA-seq data from the Cancer Genome Atlas indicated that IGF1R is shortened in both lung adenocarcinoma and lung squamous cell carcinoma compared to normal controls. CONCLUSIONS: Our findings suggest that CFIm25 plays an important role in lung cancer cell proliferation through regulating the APA of oncogenes, including IGF1R, and promoting their protein expression.


Assuntos
Proliferação de Células/genética , Fator de Especificidade de Clivagem e Poliadenilação/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/genética , Poliadenilação/genética , Fatores de Poliadenilação e Clivagem de mRNA/genética , Regiões 3' não Traduzidas/genética , Células A549 , Processamento Alternativo , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Modelos Genéticos , Interferência de RNA , Receptor IGF Tipo 1 , Receptores de Somatomedina/genética , Receptores de Somatomedina/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo
13.
Arthritis Rheumatol ; 70(10): 1673-1684, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29771006

RESUMO

OBJECTIVE: Systemic sclerosis (SSc; scleroderma) is a chronic disease that affects the skin and various internal organs. Dermal fibrosis is a major component of this disease. The mechanisms that promote dermal fibrosis remain elusive. Elevations in tissue adenosine levels and the subsequent engagement of the profibrotic A2B adenosine receptor (ADORA2B) have been shown to regulate fibrosis in multiple organs including the lung, kidney, and penis; however, the role of ADORA2B in dermal fibrosis has not been investigated. We undertook this study to test our hypothesis that elevated expression of ADORA2B in the skin drives the development of dermal fibrosis. METHODS: We assessed the involvement of ADORA2B in the regulation of dermal fibrosis using a well-established mouse model of dermal fibrosis. Using an orally active ADORA2B antagonist, we demonstrated how inhibition of ADORA2B results in reduced dermal fibrosis in 2 distinct experimental models. Finally, using human dermal fibroblasts, we characterized the expression of adenosine receptors. RESULTS: We demonstrated that levels of ADORA2B were significantly elevated in dermal fibrosis and that the therapeutic blockade of this receptor in vivo using an ADORA2B antagonist could reduce the production of profibrotic mediators in the skin and attenuate dermal fibrosis. Antagonism of ADORA2B resulted in reduced numbers of arginase-expressing macrophages and myofibroblasts and in reduced levels of the extracellular matrix proteins fibronectin, collagen, and hyaluronan. CONCLUSION: These findings identify ADORA2B as a potential profibrotic regulator in dermal fibrosis and suggest that ADORA2B antagonism may be a useful approach for the treatment of SSc.


Assuntos
Fibrose/tratamento farmacológico , Antagonistas de Receptores Purinérgicos P1/farmacologia , Escleroderma Sistêmico/tratamento farmacológico , Dermatopatias/tratamento farmacológico , Pele/patologia , Animais , Bleomicina , Modelos Animais de Doenças , Fibroblastos/efeitos dos fármacos , Fibrose/induzido quimicamente , Fibrose/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Escleroderma Sistêmico/induzido quimicamente , Escleroderma Sistêmico/patologia , Pele/efeitos dos fármacos , Dermatopatias/induzido quimicamente , Dermatopatias/patologia
14.
Am J Respir Cell Mol Biol ; 54(5): 683-96, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26452072

RESUMO

Epidemiologic evidence indicates that cigarette smoke (CS) is associated with the development of acute lung injury (ALI). We have previously shown that brief CS exposure exacerbates lipopolysaccharide (LPS)-induced ALI in vivo and endothelial barrier dysfunction in vitro. In this study, we found that CS also exacerbated Pseudomonas-induced ALI in mice. We demonstrated that lung microvascular endothelial cells (ECs) isolated from mice exposed to CS had a greater permeability or incomplete recovery after challenges by LPS and thrombin. Histone deacetylase (HDAC) 6 deacetylates proteins essential for maintenance of endothelial barrier function. We found that HDAC6 phosphorylation at serine-22 was increased in lung tissues of mice exposed to CS and in lung ECs exposed to cigarette smoke extract (CSE). Inhibition of HDAC6 attenuated CSE-induced increases in EC permeability and CS priming of ALI. Similar barrier protection was provided by the microtubule stabilizer taxol, which preserved α-tubulin acetylation. CSE decreased α-tubulin acetylation and caused microtubule depolymerization. In coordination with increased HDAC6 phosphorylation, CSE inhibited Akt and activated glycogen synthase kinase (GSK)-3ß; these effects were ameliorated by the antioxidant N-acetyl cysteine. Our results suggest that CS increases lung EC permeability, thereby enhancing susceptibility to ALI, likely through oxidative stress-induced Akt inactivation and subsequent GSK-3ß activation. Activated GSK-3ß may activate HDAC6 via phosphorylation of serine-22, leading to α-tubulin deacetylation and microtubule disassembly. Inhibition of HDAC6 may be a novel therapeutic option for ALI in cigarette smokers.


Assuntos
Lesão Pulmonar Aguda/enzimologia , Lesão Pulmonar Aguda/patologia , Endotélio Vascular/patologia , Histona Desacetilases/metabolismo , Pulmão/patologia , Fumar/efeitos adversos , Lesão Pulmonar Aguda/microbiologia , Animais , Bovinos , Permeabilidade da Membrana Celular/efeitos dos fármacos , Suscetibilidade a Doenças , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/enzimologia , Células Endoteliais/microbiologia , Células Endoteliais/patologia , Endotélio Vascular/enzimologia , Glicogênio Sintase Quinase 3 beta/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Humanos , Lipopolissacarídeos/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Microvasos/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia
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