... konulu sunumlar: "Yılın Makalesi Doç. Dr. Hasan Bayram"— Sunum transkripti:
1Yılın Makalesi Doç. Dr. Hasan Bayram Gaziantep Üniversitesi Tıp Fakültesi Göğüs Hastalıkları ADDeneysel Çalışmalar, Solunum Hücre Biyolojisi ve GenetikÇalışma Grubu
2Kronik Obstrüktif Akciğer Hastalığında Decreased Histone Deacetylase Activity in Chronic Obstructive Pulmonary DiseaseKronik Obstrüktif Akciğer HastalığındaAzalmış Histone Deacetylase AktivitesiKazuhiro Ito, Ph.D., Misako Ito, B.A., W. Mark Elliott, Ph.D., Borja Cosio, M.D.,Gaetano Caramori, Ph.D., Onn Min Kon, M.D., Adam Barczyk, M.D.,Shizu Hayashi, Ph.D., Ian M. Adcock, Ph.D., James C. Hogg, M.D.,and Peter J. Barnes, D.M., D.Sc.Airway Disease Section,National Heart and Lung Institute,Imperial College, LondonN Engl J Med 2005;352:
3Genel Bilgi KOAH, progressif olup, prev artıyor Sigaraya bağlı hava yolu inflamasyonuHava akım kısıtlılığı, pulm inflam ilişkiliKOAH’ta inflamasyon kompleksIL-8 ve LTB4 gibi kemokinler (nötrofil)TNF- pro-inflamatuar sitokinler KOAH balgamında artmışThe global burden of chronic obstructivepulmonary disease (COPD) — acommon and debilitating chronic inflammatorydisease that is characterized by the progressivedevelopment of airflow limitation and is poorlyreversible — is increasing.1Cigarette smoking isstrongly linked with the ongoing inflammation inthe airways and lung parenchyma, and the severityof airflow limitation is correlated with the degree ofpulmonary inflammation.2,3The inflammatory processes in COPD are complex.4Neutrophil chemotactic mediators, such asinterleukin-8 and leukotriene B, and proinflammatorycytokines, such as tumor necrosis factora, areincreased in the sputum of patients with COPD, ascompared with that of normal subjects.5
4NükleozomDNA nukleozomların çevreseini sarmıştır. Nükleozomlar 8 histon molekülünden yapılmış. Histon 2a, 2b, 3,4’den ikişer tane. Her histon molk.nün lizinden zengin uzun bir kuyruğu bulunur, enzim modifikasyonunun yapıldığı kısımFig. 1. Structure of chromatin. DNA is wound around nucleosomes, which are composed of 8 histone molecules with two copies of histones 2A, 2B, 3 and 4. Each histone molecule has a long tail rich in lysine residues (K), which are the sites of enzymatic modification, such as acetylation, thus changing the charge of the molecule and leading to DNA unwindingThe complex of DNA + protein = ChromatinLizinden zengin kuyruk (asetilasyon vs, DNA sarmalının açılması)İto K,
5CREB-binding protein (CBP) ve HAT, Fig. 2. Coactivators, such as CREB-binding protein (CBP) have intrinsic histone acetyltransferase (HAT) activity, resulting in opening up to the chromatin structure, which allows binding of RNA polymerase II and initiation of gene transcription. Several transcription factors interact with CBP, including CREB (cyclic AMP response element binding protein), NF-κB (nuclear factor-κB), AP-1 (activator protein-1) and STATs (signal transduction activated transcription factors).CREB-binding protein (CBP) ve HAT,kromatin açılmasına yol açar, gen transkripsiyonu,Transk fak (AP-1, NF-kB gibi). CBP ile etkileşirİto K,
6Histon asetilasyonundan sorumlu moleküller Fig. 3. Molecules responsible for histone acetylation status. Histone acetyltransferase (HAT) acetylates histones, resulting in opening up to the chromatin structure. This is reversed by corepressors, that include histone deacetylases (HDACs) and other associated corepressors which reverse this acetylation, thereby causing gene silencing.Histon asetilasyonundan sorumlu moleküllerİto K,
7Histon deasetilazların (HDAC) sınıflandırılması Fig. 4. Classification of histone deacetylase. 18 HDACs are identified and classified into 3 or 4 classes.Histon deasetilazların (HDAC) sınıflandırılmasıİto K,
8HDAC-MakrofajHDAC alv. makrofajlarda sitokin üretiminde anahtar molekülHDAC aktivitesinde düşme, KOAH’taki artmış infalamasyonla ilişkili olabilir.We have previously shown that HDAC is a keymolecule in the repression of production of proinflammatorycytokines in alveolar macrophages7Ito K, Barnes PJ, Adcock IM. Glucocorticoidreceptor recruitment of histone deacetylase2 inhibits interleukin-1 betainducedhistone H4 acetylation on lysines 8and 12. Mol Cell Biol 2000;20:;thus, a decrease in the HDAC could be associatedwith enhanced inflammation in COPD.8The presentstudy was designed to test the hypothesis thatthe magnitude of the inflammatory response in theperipheral lung that has been described in COPD isassociated with a decrease in HDAC activity.8.Barnes PJ, Ito K, Adcock IM. Corticosteroidresistance in chronic obstructive pulmonarydisease: inactivation of histonedeacetylase. Lancet 2004;363:731-3.Ito K, et al. Mol Cell Biol 2000; Barnes PJ, et al. Lancet 2004.
9Hipotez-Amaç“KOAH’ta akciğer periferinde artmış inflamasyon, azalmış HDAC aktivitesine bağlıdır.”Hipotezini test etmek.The presentstudy was designed to test the hypothesis thatthe magnitude of the inflammatory response in theperipheral lung that has been described in COPD isassociated with a decrease in HDAC activity.
11Doku Bankasından Periferik AC Spesmeni IL-8 mRNA ve IL-8 promoter’da Histon 4 asetilasyonunaHDAC aktivitesiHAT aktivitesiHDAC aktivitesi ile KOAH FEV1 arasındaki korelasyonHDAC protein ekspresyonuHasta spesmeni: Doku bankasındanNon-smoker: 11 (normal ACFigure 1. Interleukin-8 Gene Expression and Histone Deacetylase (HDAC) in Peripheral Lung Tissue from Patientswith COPD.Panel A shows interleukin-8 messenger RNA (mRNA) expression and histone-4 acetylation at the interleukin-8 promoter.Panel B shows HDAC activity. Panel C shows histone acetyltransferase (HAT) activity. The data were plotted asmeans ±SE, with the number of subjects in each group ranging from 5 to 11. (The complete data are given in Supplements1, 2, and 3 of the Supplementary Appendix.) Panel D shows the correlations between HDAC activity and the ratioof forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) in specimens obtained from normal nonsmokersand from patients with COPD at different stages. The dotted line indicates the 95 percent confidence interval ofthe regression line. When the single outlier point shown at the top right in this panel was omitted, there was still a significantpositive correlation between HDAC activity and FEV:FVC (r=0.60, P<0.001). S0, S1, S2, and S4 denote severityof disease according to the grading of the Global Initiative for Obstructive Lung Disease, with higher numbers indicatinggreater severity; PN pneumonia; and CF cystic fibrosis.We obtained specimens of lung tissue and dataon patients’ lung function from a tissue bank thatwas linked to an established patient registry.10Specimensof peripheral lung tissue were obtained from11 patients who were nonsmokers without symptomswho had normal lung function and from 29patients who were smokers: 9 with stage 0 COPD,10 with stage 1 COPD, and 10 with stage 2 COPD.Specimens of peripheral lung tissue were obtainedfrom an additional six patients with stage 4 COPDwho were undergoing lung-volume–reduction surgery.The patient registry and the tissue bank alsoprovided specimens of peripheral lung tissue fromfive patients who had a tumor that had producedobstructive pneumonia, as well as from five explantedlungs of patients with cystic fibrosis. Baselinecharacteristics of the patients are summarized inTable 1.
12(Periferik AC Dokusu) Hasta spesmeni: Doku bankasından Non-smoker: 11 (normal AC fonksiyonları)KOAH: Evre 0,1,2,Evre 4: Lung reduction cerrahisine gidenlerdenPnömoni: Malignite nedeniyle pnömoni gelişenlerden,Kistik fibrozis: 5 hastanın akciğer explantından.We obtained specimens of lung tissue and dataon patients’ lung function from a tissue bank thatwas linked to an established patient registry.10Specimensof peripheral lung tissue were obtained from11 patients who were nonsmokers without symptomswho had normal lung function and from 29patients who were smokers: 9 with stage 0 COPD,10 with stage 1 COPD, and 10 with stage 2 COPD.Specimens of peripheral lung tissue were obtainedfrom an additional six patients with stage 4 COPDwho were undergoing lung-volume–reduction surgery.The patient registry and the tissue bank alsoprovided specimens of peripheral lung tissue fromfive patients who had a tumor that had producedobstructive pneumonia, as well as from five explantedlungs of patients with cystic fibrosis. Baselinecharacteristics of the patients are summarized inTable 1.
14Alveolar makrofajlar, BAL ile alınmış Alveolar makrofajlar, BAL ile alınmış. Normal ve sigara içen ile Evre 2 veya 3 KOAH’lıdan.Alveolar macrophages were obtained by bronchoalveolarlavage from six healthy nonsmokers,six healthy current smokers, and seven patients withstage 2 or 3 COPD (Table 2). Bronchial-biopsy specimenswere collected from 14 normal subjects whowere nonsmokers, 10 patients with mild asthma and13 age-matched subjects who were smokers, and7 patients with COPD (stage 2 or 3) and 10 agematchedsmokers (Table 2). Normal healthy subjectsfor bronchoscopy studies were volunteersrecruited through advertisement. Although thesesamples were not specifically collected for this study,our study was part of a project that examined the molecularmechanism of inflammation in COPD, and itwas approved by the local research ethics committees.All subjects had provided written informedconsent for the deposition of their tissues in the tissuebank from which we obtained the specimensand for their use in research studies of this type.
15Table 2. Characteristics of Subjects Underwent Bronchial Biopsy.* Bronş biyopsileri 14 normal sigara içmeyen, hafif astımlı 10, sigara içen astımlı gruba yaşı uygun-13 kişi.7 KOAH’lı, 10 yaşı uygun smoker.Bronchial-biopsy specimenswere collected from 14 normal subjects whowere nonsmokers, 10 patients with mild asthma and13 age-matched subjects who were smokers, and7 patients with COPD (stage 2 or 3) and 10 agematchedsmokers (Table 2). Normal healthy subjectsfor bronchoscopy studies were volunteersrecruited through advertisement. Although thesesamples were not specifically collected for this study,our study was part of a project that examined the molecularmechanism of inflammation in COPD, and itwas approved by the local research ethics committees.All subjects had provided written informedconsent for the deposition of their tissues in the tissuebank from which we obtained the specimensand for their use in research studies of this type.
16İstatiksel Analiz Varyans analizi non-parametrik Kruskal-Wallis ile Anlamlı olduğunda, Mann-Whitney U ile gruplar karşılaştırılmış.Korelasyon Sperman’s rank metodu ileİki yönlü p<0.05 anlamlı bulunmuş.statistical analysisResults are expressed as means ±SE. Other measures(medians and standard deviations) are providedin the Supplementary Appendix. Analysis ofvariance was performed with the use of the nonparametricKruskal–Wallis test. When the resultwas significant, the Mann–Whitney U test was performedfor comparisons between groups (SPSSsoftware). Correlation coefficients were calculatedwith the use of Spearman’s rank method. A P valueof less than 0.05 was considered to indicate statisticalsignificance. All reported P values are two-sided.
18Peripheral Lung Tissue from Patients with COPD Periferik AC dokusunda (doku bankası) alınan dokuda solda IL-8 mRNA ekspresyonu ve IL-8 promoter bölgesinde histon asetilasyonunuVS Non-smokers.Sağdaki grafik aynı dokuda HDAC aktivitesini gösteriyor.Promoter: DNA’da RNA polimerazın bağlanıp transkripsiyonun başlayacağı bölge.Figure 1. Interleukin-8 Gene Expression and Histone Deacetylase (HDAC) in Peripheral Lung Tissue from Patientswith COPD.Panel A shows interleukin-8 messenger RNA (mRNA) expression and histone-4 acetylation at the interleukin-8 promoter.Panel B shows HDAC activity.) to forced vital capacity (FVC) in specimens obtained from normal nonsmokersand from patients with COPD at different stages. The dotted line indicates the 95 percent confidence interval ofthe regression line. When the single outlier point shown at the top right in this panel was omitted, there was still a significantpositive correlation between HDAC activity and FEV1:FVC (r=0.60, P<0.001). S0, S1, S2, and S4 denote severityof disease according to the grading of the Global Initiative for Obstructive Lung Disease, with higher numbers indicatinggreater severity; PN pneumonia; and CF cystic fibrosis.*IL-8 mRNA ve IL-8 promoter’daHiston 4 asetilasyonu*Hastalığın şiddeti ile pozitif korelasyonHDAC aktivitesi
19Peripheral Lung Tissue from Patients with COPD Solda, periferik AC dokusunda Histon asetil transferaz aktivitesi görülüyor. Anlamlı bir fark yok.Sağdaki grafikte HDAC aktivitesi ile KOAH’ta % FEV1/FVC arasındaki korelasyon görülüyor. FEV1 ile HDAC aktivitesi arasında pozitif korelasyon görünüyor.Panel C shows histone acetyltransferase (HAT) activity. The data were plotted asmeans ±SE, with the number of subjects in each group ranging from 5 to 11. (The complete data are given in Supplements1, 2, and 3 of the Supplementary Appendix.) Panel D shows the correlations between HDAC activity and the ratioof forced expiratory volume in one second (FEV1) to forced vital capacity (FVC) in specimens obtained from normal nonsmokersand from patients with COPD at different stages. The dotted line indicates the 95 percent confidence interval ofthe regression line. When the single outlier point shown at the top right in this panel was omitted, there was still a significantpositive correlation between HDAC activity and FEV:FVC (r=0.60, P<0.001). S0, S1, S2, and S4 denote severityof disease according to the grading of the Global Initiative for Obstructive Lung Disease, with higher numbers indicatinggreater severity; PN pneumonia; and CF cystic fibrosis.HAT aktivitesi ve KOAHHDAC aktivitesi ve %FEV1/FVC
20KOAH’ta Periferik AC dokusunda Histone Deacetylase (HDAC) Gen EkspresyonuFigure 2. Histone Deacetylase (HDAC) Expression in Peripheral Lung Tissue.Panel A shows the expression of histone deacetylase (HD) genes 1 through 8 with the use of real-time PCR.In Panel A, there were significant differences (asterisks indicate P<0.05 anddaggers P<0.01 for the comparison with nonsmokers, and double daggers P<0.05 and section marks P<0.01 for thecomparison with patients with COPD stage 0)HDAC 1-8 gen ekspresyonu, ‘real time’ PCR (* VS non-smoker ve sO.)
21KOAH’ta Periferik AC dokusunda Histone Deacetylase (HDAC) Protein EkspresyonuBu grafikte WB aracılığıyla, periferik AC dokusundaki HDAC2 ekspresyonunu görüyorsunuz. Sağdaki grafik soldaki WB görüntülerinin dansitometrik analizinden hazırlanmış.VS Non smokersPanel Bshows HDAC2 protein expression with the use of Western blotting and lamin A and lamin C (lamin A/C) nuclear membraneproteins as an internal control for nuclear-protein loading. Panel C shows the densitometric analysis of HDAC2protein expression in samples of peripheral lung tissue from healthy nonsmokers (NS) and from patients with COPDstage 0 (S0), stage 1 (S1), stage 2 (S2), and stage 4 (S4).
22Alveolar Makrofajlar HDAC ve HAT aktivitesi HDAC mRNA ekspresyonu Soldaki grafide Non-smoker, smoker ve KOAH’lıların makrofajlarındaki HDAC ve HAT aktivitesi görülüyor. Gördüğünüz gibi KOAH’lılarda HDAC aktivitesi anlamlı olarak azalmış.Sağdaki grafikde HDAC mRNA ekspresyonu görülüyor. Panel A shows HDAC activity and HAT activity. Panel B shows expression of HDAC (HD) 1 through 8 mRNA in alveolar macrophages.VS Non-smokersFigure 3. Histone Deacetylase (HDAC) and Histone Acetyltransferase (HAT) Activity in Alveolar Macrophages and Bronchial-BiopsySpecimens.Panel A shows HDAC activity and HAT activity. Panel B shows expression of HDAC (HD) 1 through 8 mRNA in alveolar macrophages.HDAC ve HAT aktivitesiHDAC mRNA ekspresyonu
23Bronş Biyopsileri HDAC Aktivitesi HAT Aktivitesi Bu durum sadece KOAH’a mı özgü? Yoksa hava yollarında obstrüksiyonla mı ilişkili? Astımda durum ne?Bronş biyopsilerindeki HDAC ve HAT aktivitesini görüyorsunuz. Grup 1 kontrol (astım için?, daha genç) Grup 2 (KOAH için?, daha yaşlı)’ye göre daha genç. Hastalar steroid almamışlardır.VS Non-smokers, solda COPD vs Grup 2 smoker.Figure 3. Histone Deacetylase (HDAC) and Histone Acetyltransferase (HAT) Activity Bronchial-BiopsySpecimens.Panel C shows HDAC activity. Panel D shows HAT activity in bronchial-biopsy specimens obtained from healthy nonsmokers, healthy smokers(those in group 1 are younger than those in group 2), and patients with COPD and those with mild asthma that had not previously beentreated with steroids. The results are plotted as means ±SE, with the number of subjects in each group ranging from 6 to 14. In Panels A, C,and D, P values for the comparison with nonsmokers are shown above each bar. In Panel B, the significant differences are shown by the symbolsabove the bars (the asterisk indicates P<0.05 and the daggers P<0.01 for the comparison with nonsmokers). (HDAC AktivitesiHAT Aktivitesi
24Sonuçlar: Periferik AC Dokusunda IL-8 mRNA ve IL-8 promoter’da Histon 4 asetilasyonu Evre 2, 3 KOAH’da HAT aktivitesi HDAC aktivitesi HDAC aktivitesi ile KOAH’ta FEV1, %FEV1/FVC arasında + korelasyonHDAC ekspresyonu Evre 4 KOAH’ta Evre 0 KOAH ve ‘non-smoker’ lara göre
26Sonuçlar: Bronş Biyopsileri (KOAH - Hafif Astım) HAT aktivitesiKOAH’ta Astımda HDAC aktivitesiKOAH’ta Astımda
27Tartışma-1HAT/HDAC aktivasyonundaki denge periferik AC dokusunda histon hiperasetilasyonundaki artışa kayıyorBu KOAH’a spesifik olabilir (Astım, kistik fibrozis, pnömonide bu gözlenmemiş)Astımda HAT aktivitesindeki artış önceki bulgularıyla korele*There was a positive correlationbetween histone-4 acetylation and HDACactivity (P<0.001), indicating that the balance betweenHAT activity and HDAC activity is shifted towardhistone hyperacetylation in the peripheral lungof patients with COPD.These changes may be relativelyspecific to COPD, because we could not finda reduction in total HDAC activity in samples frompatients with asthma, cystic fibrosis, or pneumonia(Fig. 1 and 3).In contrast, in asthma, which alsoinvolves increased expression of inflammatorygenes in the respiratory tract, we confirmed previousobservations14showing increased HAT activityin bronchial-biopsy specimens.*Ito K, et al. Am J Respir Crit Care Med 2002.
28Tartışma-2Astım (HAT ) ve KOAH’ta (HDAC ) kromatin, farklı mekanizmalarla hiperasetile oluyorBu kromatinin açılmasına, ve inflamatuar gen ekspresyonunda artışa yol açıyorIn contrast, in asthma, which alsoinvolves increased expression of inflammatorygenes in the respiratory tract, we confirmed previousobservations14showing increased HAT activityin bronchial-biopsy specimens. Thus, in both asthmaand COPD, chromatin appears to be hyperacetylatedbut by means of different mechanisms, andthis increased histone acetylation provides a mechanismfor local unwinding of chromatin and a subsequentincrease in inflammatory gene expression.6Thisfinding suggests that the clinical stage of COPDmay be related to reduced HDAC activity, and thisreduced activity, in turn, could facilitate increasedexpression of the relevant inflammatory genes.
29Tartışma-3 Histon asetilasyonunu regule eden 11 HDAC var HDAC2 inflamatuar gen ekspresyonunun düzenlenmesinde etkiliHDAC3, 5, ve 8 hücre siklüsü, diferansiasyonu ve apoptozisinde etkili*HDAC3, 5, 8 KOAH , mekanizmalar?There are 11 classic human HDACs that regulatehistone acetylation.15We previously reportedthat HDAC2 is involved in suppression of NFkB–mediated inflammatory gene expression by corticosteroids.7In the present study, we have shownthat HDAC2 mRNA and protein expression is significantlyreduced in tissue specimens of the peripherallung and in alveolar macrophages from patientswith COPD.HDAC3, 5, and 8 are also reduced in lung tissueand macrophages. These HDAC isoforms are reportedto be involved in the cell cycle, cell differentiation,and apoptosis.Further experimentswill be required to clarify how the reduced functionof these HDACs influences the inflammatory processin COPD.de Ruijter AJ, van Gennip AH, CaronHN, Kemp S, van Kuilenburg AB. Histonedeacetylases (HDACs): characterization ofthe classical HDAC family. Biochem J 2003;370:16.Durst KL, Lutterbach B, Kummalue T,Friedman AD, Hiebert SW. The inv(16) fusionprotein associates with corepressorsvia a smooth muscle myosin heavy-chaindomain. Mol Cell Biol 2003;23:17.Bertos NR, Wang AH, Yang XJ. Class IIhistone deacetylases: structure, function,and regulation. Biochem Cell Biol 2001;79:*de Ruijter AJ, Biochem J 2003; Bertos NR, Biochem Cell Biol 2001
30Tartışma-4 Düşen HDAC aktivitesi reversible olabilir Teofilin HDAC aktivatörü (Ito K, 2002)Düşük teofilin alv macroph azalmış HDAC aktivitesini düzeltmiş, inf sitokin salınımını, steroid cevabını restore*Bu etkinin kliniğe yansıması??We speculate that our findings may have therapeuticimplications, because reductions in HDACactivity may be reversible. Theophylline is an activatorof HDAC,13and we have recently shown thatlow concentrations of theophylline completely restoreHDAC activity in alveolar macrophages frompatients with COPD, with reduced production of inflammatorycytokines and restoration of responsivenessto corticosteroids.18Whether this is a mechanismof the therapeutic action of theophylline inCOPD is not known. We report that total HDACactivity and the expression of specific HDAC isoenzymesare decreased in peripheral lung tissue,bronchial-biopsy specimens, and alveolar macrophagesof patients with COPD and that this findingis related to increasing disease severity. This findingcould in part account for the increased inflammatoryresponse in the respiratory tract of patientswith COPD.*Cosio BG, J Exp Med 2004.
31Yorum - ArtılarKOAH’taki inflamasyonun anlaşılmasında farklı bir boyut, yeni bir teoriIn vivo ve in vitro ayağı çok iyi kombine eden bir çalışmaKOAH’ta tedaviye farklı bir boyut getirebilecek verilerBaşarıya ulaşırsa NOBEL!?
32Yorum - EksilerPeriferik doku, doku bankası yerine prospektif olarak alınsa daha iyi olurduBiyopsi ve BAL (makrofaj için) çalışmasında Evre 2-3 KOAH kombine edilmiş
33EDITORIAL COPD Unwound Steven D. Shapiro, M.D. N Engl J Med 2005;352:
34ve Histon asetilasyonu KOAH’taİnflamatuarhücreİnteraksiyonuve Histon asetilasyonuFigure 1. Inflammatory-Cell Interactions in Chronic Obstructive PulmonaryDisease (COPD) and the Role of Histone Acetylation.Reactive oxygen species resulting from inhaled cigarette smoke (and potentiallyfrom the inflammatory cells themselves) promote transcription of nuclearfactorkB (NFkB)–mediated proinflammatory factors by way of two mechanisms.First, oxidation results in the degradation of IKkB, releasing NFkB, which then translocates to the nucleus of the targeted cell. Oxidation also inactivateshistone deacetylase (HDAC), shifting the balance to increased DNA acetylation,weakening the interactions between histone and DNA and “unwinding” DNA,allowing NFk B greater access to the DNA promoter elements, andleading to transcription of neutrophil chemokines and cytokines (tumor necrosis factora [TNFa ] and interleukin-8)and matrix metalloproteinases (MMPs). These factors recruit and activate neutrophils to the lung.In addition, CD8+ T cells augment the production of macrophage MMPs through interactions with surface-bound CD40 molecules and interferon-inducible chemokines (inducible protein of 10 kD [IP-10], interferon-inducible T-cellalpha chemoattractant [I-TAC], and monokine induced by interferong [MIG]).Macrophage MMPs and neutrophil elastase degrade each other’s inhibitors,the tissue inhibitor of metalloproteinases and alpha1-antitrypsin, respectively,augmenting their matrix-degrading capacities. These interactions illustratethe highly interactive nature of the immune inflammatory response and suggestthat breaking this cycle, perhaps by way of augmentation of HDAC withthe use of theophylline, may prevent inflammatory-mediated destruction ofthe lung in COPD. Dashed lines indicate inhibition.
35Editorial-1KOAH’ta sorun, doku destrüksiyonuna yol açan inflamatuar hücre ve mediatörler arasındaki etkileşimi modifiye etmek, bu kısır döngüyü kırmak.Sigara inflamasyonu başlatıyor, ancak bıraktıktan sonra da devam ediyor.Olay sanıldığından karmaşıkThe challenge nowis to understand the interplay between different immuneand inflammatory cells and the mediatorsthey produce that lead to tissue destruction. If wecan do this, then we may be able to find safe and effectivemeans to inhibit this destructive cascadeand prevent disease progression.If only it were so simple; the data suggest thepresence of a moving inflammatory target. Cigarettesmoke initiates inflammation, in part by wayof the oxidation effects discussed above, yet in severeCOPD, other factors appear to sustain inflammationlong after smoking cessation. This differencewas best shown in a study that examined thelung tissue of patients with end-stage COPD whohad not smoked a cigarette in more than nine years(on average).5Rather than being “burned out,” asexpected, the lungs were filled with a variety of inflammatorycells. Whether the inflammation is relatedto bacterial colonization, latent viral infection,residual matrix fragments, or other mechanisms isnot clear. What is clear is that after a certain thresholdof disease severity is passed, simply quittingsmoking may not be sufficient to prevent diseaseprogression.
36Editorial-2Sigara KOAH’ta önemli risk faktörü, ancak ¼ kişide gelişiyorAstım diğer bir inflamatuar hastalıkAcaba KOAH ve astım aynı patolojinin farklı fenotipleri mi ? (‘Dutch’ Hipotezi)İkisi farklı patolojiler? (‘İngiliz Hipotezi’)Astımda steroid etkili (steroid reseptörü HDAC’a bağlanıp, etki için onu nükleusa transloke ediyor)Asthma is another common inflammatory lungdisease. The similarities and differences betweenasthma and COPD engendered a feud between theDutch and the British that has raged for nearly halfa century. The difference in the response to corticosteroidsin patients with asthma and in those withCOPD in relation to HDAC signaling has workedits way into this debate. The controversy centers onan explanation of the observation that even thoughcigarette smoking is the overwhelming risk factorfor COPD, the disease develops in only a minorityof smokers. In 1961, Orie and colleagues advancedthe hypothesis that the obstructive airway diseases,including asthma, chronic bronchitis, and emphysema,represent different phenotypes of a commonpathogenetic process.6This theory was later labeledthe Dutch hypothesis and has evolved intothe concept that asthma and COPD have commonorigins. The British proposed a competing theorythat stated that smokers with chronic productionof sputum were the ones at increased risk for thedevelopment of COPD.Epidemiologic studies have not supported theBritish hypothesis. However, this does not meanthat there is universal acceptance of the Dutch hypothesis.In fact, at the 2003 meeting of the AmericanThoracic Society, one of the authors, Dr. Barnes,claimed in discussion that “the Dutch were confused.Some patients with COPD also have asthma.”Arguing against the Dutch hypothesis, Dr. Barnescould point to the fact that corticosteroids are muchmore effective in asthma than in COPD. The reasonfor this difference is that in asthma corticosteroidsstimulate the glucocorticoid receptor that bindsHDAC and translocates it to the nucleus for action,
37Editorial-3 KOAH’ta oksidanlara bağlı HDAC, steroid cevabı yok Sigara içen astımlılarda steroide cevap azalmalı,Çalışmalar bu konsepti destekliyor.*NHLBI, geniş prospektif bir çalışmayı bitirmek üzere (sigara-astımda steroid)Daha çok çalışmaya ihtiyaç varwhereas in COPD oxidant-modified HDAC will notinteract with the glucocorticoid receptor. This theorywould also predict that corticosteroids are lesseffective in patients with asthma who smoke. Indeed,two small prospective studies confirmed thatpatients with stable asthma who smoked had animpaired response to either inhaled or oral corticosteroids.7The National Heart, Lung, and Blood Institute’sAsthma Clinical Research Network has almostcompleted a larger prospective randomizedtrial based on this issue (Smoking Modulates Outcomesof Glucocorticoid Therapy in Asthma).*Chaudhuri R,et al. Am J Respir Crit Care Med 2003.
38Editorial-4 Yeni çalışmalar!!! Astım ve KOAH tek hastalık gibi değil Etkileşim var, bir birlerini ağırlaştırabilirler (KOAH, steroid dirençli astım)KOAH ciddi sorunHDAC teorisi çalışırsa, Teofilin ve steroid kombinasyonu KOAH’ta önemli iş görebilirYeni çalışmalar!!!Although, admittedly, asthma and COPD are unlikelyto represent a single disease, they probablyshare pathogenetic mechanisms that interact, eachmaking the other disease process worse. Theseinteractions may become important as we searchfor effective therapy for steroid-resistant asthmaand COPD.COPD is now epidemic worldwide, and we havefew effective therapies to offer patients as they slowlysuffocate. But the HDAC theory may be more thanmolecular medicine for its own sake. A potentialpractical implication of the theory derives from theobservation that low-dose theophylline markedlyinduces HDAC transcription. If true, then the combinationof corticosteroids and theophylline shouldrestore delivery of HDAC to the nucleus and disarminflammation in COPD.8I look forward to a futurestudy showing that the combination of these twowell-known drugs inhibits disease progression inpatients with COPD.
41Sigara içicilerinin makrofajlarında HDAC2 Ito K, 2006,www.ttmed.com/respiratory
42KOAH’ta Steroid Direnci Mekanizmaları Fig. 13. Proposed mechanism of amplified inflammation and corticosteroid resistance in COPD patients. Stimulation of normal alveolar macrophages activates nuclear factor- k B (NF-κB) and other transcription factors to switch on histone acetyltransferase leading to histone acetylation and subsequently to transcription of genes encoding inflammatory proteins, such as tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8) and matrix metalloproteinase-9 (MMP-9). HDAC2 itself reverses histone acetylation, or corticosteroids reverse this by binding to glucocorticoid receptors (GR) and recruiting histone deacetylase-2 (HDAC2). This reverses the histone acetylation induced by NF-κB and switches off the activated inflammatory genes. In COPD patients cigarette smoke activates macrophages, as in normal subjects, but oxidative stress (acting through the formation of peroxynitrite) impairs the activity of HDAC2. This amplifies the inflammatory response to NF-κB activation, but also reduces the antiinflammatory effect of corticosteroids as HDAC2 is now unable to reverse histone acetylation.Ito K, 2006,www.ttmed.com/respiratory
43Teofilin ağır sigara içicilerinin ve KOAH’lıların Makrofajlarında azalan HDAC aktivitesini düzeltiyorFig. 12. Effect of theophylline on HDAC activity reduced in heavy smokers and patients with COPD. Alveolar macrophages were obtained from heavy smokers and patients with COPD. Theophylline at 10-6 M or 10-5 M was added to nuclear extracts from each patient and HDAC activity was determined with commercial kit. (Adapted from Cosio, B.G. et al. J Exp Med 2004, 200: by copyright permission of The Rockefeller University Press. JEM Online,
44Teşekkürler Claude Monet, Waterloo Bridge, London, 1903 Monet’in tablosunda görüldüğü gibi hava kirliliği 19.yy başlarında başta Endüstrileşmiş ülkelerde ortaya çıkmış ve sağlığı ciddi şekilde tehdit etmiştir. Bir yandan da neden olduğu farklı ışık yansımaları ile Monet gibi sanatçılara esin kaynağı olmuştur. Ancak bu gün Londra’da Waterloo köprüsünün yanında dururken artık bu manzarayı görmüyorsunuz. Bu manzara ne yazıkkiFIG 1. Claude Monet, Waterloo Bridge, This is one of a total of 36 paintings he made of this subject,illustrating the interplay between changing light conditions and the air pollutants derived from open coalburning. This example hangs in the Hermitage Museum in St Petersburg and was photographed by theauthor. Claude Monet, Waterloo Bridge, Effect of Fog, reproduced by permission of The State HermitageMuseum, St Petersburg, Russia.J ALLERGY CLIN IMMUNOL FEB 2005TeşekkürlerClaude Monet, Waterloo Bridge, London, 1903
45Teofilinin KOAH’ta etkileir ZuWallack RL, et al. Salmeterol plus theophylline combination therapy in the constriction in asthma: antagonism by inhaled theophylline. Am Rev Respir Dis 1984;129:380–384. treatment of COPD. Chest 2001;119:1661–1670.Kirsten DK, et al. Effects of theophylline withdrawal in severe chronic obstructive pulmonary disease. Chest 1993;104:1101–1107.Chrystyn H, et al. Dose response relation to oral theophylline in severe chronic obstructive airway disease. BMJ 1988; 297:1506–1510.18. ZuWallack RL, Mahler DA, Reilly D, Church N, Emmett A, Rickard K, Knobil K. Salmeterol plus theophylline combination therapy in the constriction in asthma: antagonism by inhaled theophylline. Am RevRespir Dis 1984;129:380–384. treatment of COPD. Chest 2001;119:1661–1670.19. Kirsten DK, Wegner RE, Jorres RA, Magnussen H. Effects of theophylline withdrawal in severe chronic obstructive pulmonary disease. Chest1993;104:1101–1107.20. Chrystyn H, Mulley BA, Peake MD. Dose response relation to oraltheophylline in severe chronic obstructive airway disease. BMJ 1988; 297:1506–1510.
46KOAH’ta steroid direnci Fig. 11. Possible mechanism of reduction in histone deacetylase 2 (HDAC2). HDAC2 is inactivated by peroxynitrite, generated by an interaction of nitric oxide (NO) generated by NO synthase (NOS) and cigarette smoke and superoxide anions (·O2-). Peroxynitrite nitrates tyrosine (Tyr) residues on HDAC2 and this may block enzymatic activity and also mark the enzyme for ubiquitination (Ub) and destruction by the proteasome. The loss of HDAC2 leads to amplification of the inflammatory response and resistance to corticosteroids.Ito K, 2006,www.ttmed.com/respiratory
47Histon Asetil Transferaz- Histon Deasetilaz Nükleer enzimlerKromatin yapısını regüle ederek inflamatuar gen ekspresyonunu modifiye ederlerHistoneacetyltransferase (HAT) and histone deacetylase(HDAC) are families of nuclear enzymes that modifythe expression of inflammatory genes by regulatingchromatin structure.
48Histon AsetilasyonuTranskripsiyon ko-aktivatör proteinler histon asetil transferaz aktivitesi gösterirlerKromatin yapısını değiştirirTranskripsiyon faktörleri ve RNA polimeraz II’nin DNA bağlanmsına izin verirGen transkripsiyonunu artırırKor histonların deasetilasyonu gen transkripsiyonu baskılarAcetylation of the core histonesby transcriptional coactivator proteins, whichpossess intrinsic HAT activity, leads to changes inthe chromatin structure that subsequently allow thetranscription factors and RNA polymerase II to bindto DNA and enhance gene transcription. Conversely,deacetylation of the core histones is generallyassociated with the repression of transcription.