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Lawrence Wu, Ph.D Associate Professor Institute of Medical Sciences Tzu Chi University

Whole genome methylation profiling difference in PBMC between responder and nonresponder of acute exacerbations of COPD patients treated with corticosteroid. Lawrence Wu, Ph.D Associate Professor Institute of Medical Sciences Tzu Chi University. COPD.

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Lawrence Wu, Ph.D Associate Professor Institute of Medical Sciences Tzu Chi University

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  1. Whole genome methylation profiling difference in PBMC between responder and nonresponder of acute exacerbations of COPD patients treated with corticosteroid Lawrence Wu, Ph.D Associate Professor Institute of Medical Sciences Tzu Chi University

  2. COPD • Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality throughout the world, and further increases in its prevalence and mortality can be predicted in the coming decades. • The World Health Organization has predicted that it will be the third leading cause of death in the world by the year 2020. • The clinical course of the disease is characterized by progressive, irreversible airflow obstruction associated with chronic inflammation of the respiratory tract. • However, there are still no effective drug therapies for COPD that alter disease progression.

  3. a cough that lasts a long time, or coughing up mucus • feeling short of breath, especially when you are making an effort (climbing stairs, exercising) • many lung infections that last a long time (the flu, acute bronchitis, pneumonia, etc.) • wheezing (a whistling sound when you breathe) • feeling tired (fatigue) • losing weight without trying

  4. AECOPD • Acute exacerbations are triggered mainly by respiratory tract infections. • According to evidence-based reviews and current guidelines, systemic glucocorticoid therapy is an integral part of the management of COPD exacerbations

  5. Steroids treatment • Steroids are often used in the treatment of AECOPD. • Use of corticosteroids has been shown to shorten recovery time, hasten improvement in lung function, reduce the risk of early relapse and reduce length of hospital stay. • The existing guidelines suggest that oral administration of corticosteroids in a dose of 30–40 mg prednisolone per day for 10–14 days is preferable.

  6. Study subjects • All 60 enrolled patients with COPD exacerbation were received medicine including Predisolone 2 tablet (5mg/tablet) three times a day, Medicon 1 tablet three times a day, Ventolin 1 tablet three times a day, and Bisolvon 1 tablet three time a day. The treatment duration is two weeks (14 days). • Subjects were improved all evaluation (CAT, spirometry test) after treatment and defined as responder of corticosteroid treatment. Other subjects without improved CAT and spirometry test after treatment were defined as non-responder of corticosteroid treatment.

  7. CAT is usefulness in evaluating COPD exacerbation Mackay AJ et al. Am J RespirCrit Care Med Vol 185, Iss. 11, pp 1218–1224, Jun 1, 2012 • The CAT provides a reliable score of exacerbation severity. Baseline CAT scores are elevated in frequent exacerbators. • CAT scores increase at exacerbation and reflect severity as determined by lung function and exacerbation duration.

  8. COPD Assessment Test (CAT)

  9. COPD is progressive disease, the FEV1and FVC is no significant alteration in many COPD patients in acute exacerbation during the two-week medical treatment • FEV1, FEV1% and FVC are objective measurements. CAT is subjective questionnaire. Patients with better FEV1, FVC and CAT score (more than 5 points decrease) after treatment were defined as response to corticosteroid. • The poor response group was defined as that FEV1 and FVC after 2 week treatment did not better than before treatment and CAT score didn’t decrease (more than 5 points) or increased after treatment.

  10. Results • Subjects characters The total 24 COPD patients were enrolled and DNA samples were obtained from subjects’ PBMC. The good response group included 9 males and 3 females and the poor response group was all males. All subjects were diagnosis to COPD at first time and never treated with corticosteroid before. The subject counts with different lung function in good and poor response groups are mild 4/5, moderate 5/4 and severe obstruction 3/3, respectively. The average age of two groups was no significant difference.

  11. Bisulfate conversion

  12. Genome-wide methylation chip • 24 selected patients’ PBMC DNA were subjected to genome-wide methylation analysis • 500 ng of each sample underwent bisulfite conversion using the EZ DNA methylation kit. • Bisulfite converted DNA samples were then subjected to methylation profiling on the Infinium® HumanMethylation450 BeadChips

  13. Genomic location of selected methylation site

  14. Figure 1. heatmap of methylation pattern, left side (12 subjects): good prognosis patients, right side (12 subjects) : poor prognosis patients

  15. Gene with different methylation level between two study groups

  16. False discovery rate adjust

  17. Several genes methylation status is powerful to distinguish different prognosis AVG: methylation level;△ AVG =AVG of good prognosis – AVG of poor prognosis; max: maximum value; min: minimal value

  18. Genomic location…..

  19. Some thought about candidate genes • FLAP (ALOX5AP) inhibitors for the treatment of inflammatory diseases (Sampson AP. CurrOpinInvestig Drugs. 2009 Nov;10(11):1163-72.). Does patients with high level methylation reduce the ALOX5AP expression in PBMC cell and obtain the result similar to FLAP inhibitors treatment? • Gene expression profiling of lung from emphysema patients identified seven candidate genes associated with emphysema severity including GSTM3. (Francis SM et al. Respir Res. 2009 Sep 2;10:81.) Glutathione S-transferases (GSTs) detoxify toxic compounds in tobacco smoke via glutathione-dependent mechanisms. Few studies have also found an increase in GSTM3 expression in mild/moderate COPD smokers; this strengthens their role as protective intracellular and extracellular lung mediators (Bentley AR et al. Thorax 2008, 63(11):956-61. Harju T et al. Respiratory research 2008, 9:80.) Does low level methylation increase the GSTM3 expression in PBMC cell and protect the lung function decline? • Many cases of glucocorticoid resistance may be due to mutations or polymorphisms present in the glucocorticoid receptor gene (GR/NR3C1). (Bray PJ and Cotton RG. Hum Mutat. 2003;21:557-68. ) Does high level methylation decrease NR3C1 expression in PBMC cell and increase the risk of glucocorticoid resistance?

  20. COPD methylation profiling : transcription factor analysis 485566 probes 50 probes > 0.25 △ AVG Count probes (>0.1△ AVG ) among upstream 50k and downstream 50k cg14302130 Probe >0.25 3 probes with count 10 1 probe with count 7 3 probes with count 3 5 probes with count 2 38 probes with count 1 chr6 chr8 chr8,2,7 50k 50k chrX,4,4,5,13

  21. methylation probes (>0.1)

  22. HLA-DPA1 chr6:33032346-33041454 Human TFBS -545 -424 -4219 -4098 -4673 -4552 HLA-DPA1

  23. Further thinking……. • Do the different response groups indicate two subtypes of COPD? • Is the pharmacoepigenetics helpful to reveal heterogeneity of COPD? • HLA-DPA1 vs. COPD: MHC class II antigen involving pathological mechanism of COPD?

  24. COPD p vs. control COPD vs. control COPD g vs. control Control subjects without lung diseases were selected from another study.

  25. COPD vs. control

  26. Preliminary functional analysis by bioinformatics methods using DAVID • Poor response COPD group: related genes located to membrane and associated to glycoprotein (p <0.02) • Good response COPD group: related genes associated to Ubl conjugation pathway (p<0.003) , nicotinamide nucleotide metabolism (p<0.008) ,alkaloid metabolic process (p<0.009) and regulation of glucose metabolic process (p<0.006) *DAVID: The Database for Annotation, Visualization and Integrated Discovery

  27. 35 genes • plasma membrane (p=0.03) • cell junction(p=0.04) • serine/threonine-protein kinase (p=0.04) • 43 genes • negative regulation of kinase activity (p=0.004) • purineribonucleotide binding (p=0.03) • DNA metabolic process/Purine metabolism(p=0.02)  • 43 genes (overlap of 3 circles) • positive regulation of apoptosis (p=0.09) • steroid metabolic process (p=0.02)

  28. Non-COPD vs. All COPD Top five significant genes

  29. Conclusion • The DNA methylation should be a good biomarker for investigating the pharmaco-epigenetics of COPD. • Methylation status of COPD susceptibility gene(s), inflammatory gene(s) and glucocorticoid receptor gene associate to outcome of 2-week corticosteroid treatment in AECOPD patients • Responsiveness of corticosteroids, should reflect COPD heterogeneity, especially in pathology involving DNA methylation.

  30. Future works • To link the prognosis of COPD and DNA methylation. • To find the new candidate gene(s) or pathological mechanism of COPD by DNA methylation approach

  31. Acknowledgement • Dr. Shih-Wei Lee (General Taoyuan Hospital) • Dr. Paul Wei-Che Hsu (Bioinformatics service center, IMB, Academia Sinica) • Dr. Jiu-Yao Wang (NCKU)

  32. Thank you for your attention

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