Equilíbrio HAT/HDAC, encurtamento telomérico e o papel dos monócitos do sangue periférico na geração de macrófagos M1 e M2 nos diferentes fenótipos e gravidade da DPOC

Abstract

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous pathology in its clinical presentation. Three main phenotypes are proposed: mixed COPD-asthma, exacerbator and emphysema; as well as different degrees of the disease: mild, moderate, severe, and very severe. Although many cell types contribute to the pathophysiology of the disease, macrophages are the ones that have the greatest effect on the inflammatory condition of COPD. The molecular basis of inflammation amplification in COPD has not yet been fully elucidated, the balance of histone acetyltransferases (HATs) and histone deacetylases (HDACs) have been reported as influential elements in the transcription of pro-inflammatory genes. Furthermore, COPD has been an aging-related disease. The inflammatory response and cellular senescence are critical events in its pathogenesis. The aim of this study was to investigate the expression of HATs and HDACs, telomere length, monocyte profile and their differentiation potential for M1 and M2 type macrophages in different clinical phenotypes and disease severity. Contributed to this research, 105 volunteers with COPD treated at the pneumology ambulatory of the Piquet Carneiro University Polyclinic, 42 smokers and 73 non-smokers control volunteers. Evaluation of HAT and HDAC expression and relative analysis of telomere length of peripheral blood cells were performed by real-time PCR. Characterization of the profile of classical, intermediate, and non-classical peripheral blood monocytes and the M1 and M2 profile of differentiated monocytes were performed by flow cytometry. The differentiation of monocytes was induced, during five days, in 4 different culture conditions: M1 (GM-CSF or GM-CSF + LPS) and M2 (M-CSF or M-CSF + IL-4). We identified a reduction in HDAC2 in mild, moderate, and severe COPD patients, in addition to, a significant reduction in HDAC3 expression in moderate and severe COPD patients, an increase in HDAC4 expression in mild COPD, and a reduction in EP300 (HAT) expression in severe COPD. Regarding the phenotypes, there was a significant reduction in HDAC2 expression in those classified as emphysema and exacerbator and a reduction in HDAC3 only in the emphysema phenotype. Surprisingly, telomere shortening was verified in smoker volunteers, mixed COPD-asthma, exacerbator and emphysema patients, as well as in classifications of all disease degrees. We also found an increase in intermediate and non-classical monocytes in patients with mild, moderate, severe and very severe COPD. The exacerbator phenotype showed an increase in intermediate and non-classical monocytes. Regarding the profiles of differentiated cells, patients with COPD showed a predominance of markers CD163 and CD206, related to the M2 subtype. Our data suggest that patients with COPD have important genetic changes, with different signatures between phenotypes and severity stages, as well as changes in cell profiles, determinants to the quality of the immune response and important for future treatments and personalized therapies.