1.The Clinical Characteristics Of COPD With Bronchiectasis 2.The Role Of TROP2 In Airway Basal Cells Of COPD On The Regulation Of Epithelial-mesenchymal Trophic Unit

BackgroundBronchiectasis has been identified as the comorbidity of Chronic Obstructive Pulmonary Disease(COPD)in Global Initiative for Chronic Obstructive Lung Disease(GOLD)since the year 2014.The updated versions of GOLD have underlined the impact that bronchiectasis has on natural course and prognosis of COPD.The definition of bronchiectasis is described as irreversible and progressive dilation of airways on account of chronic airway injury.Bronchiectasis is not an independent disease,and other conditions that influence the defense function of airways could lead to bronchiectasis.COPD has been regarded as one of the etiologies or related diseases of bronchiectasis.The major lesion of COPD and bronchiectasis are in the airways,with significant heterogeneous.Recently,studies focusing on the co-existence of COPD and bronchiectasis have caught increasing attention.The frequency of acute exacerbations,severity of airflow limitation,characteristics of pathogenic microorganism and prognosis are the main topics.However,limited researches are performed on the prevalence and risk factors of bronchiectasis in COPD,the mechanism between COPD and bronchiectasis,and the influence of bronchiectasis on COPD.It is significant to focus on above aspects for the diagnosis and effective treatment and prevention of COPD with bronchiectasis.The present study aims to explore the clinical characteristics of COPD with bronchiectasis.Part One:The prevalence and phenotype characteristics of COPD with bronchiectasisObjectives:To study the prevalence,clinical and phenotype characteristics of COPD with bronchiectasisMethods:(1)In this retrospective study,COPD and non-COPD patients were consecutively retrieved from April 2012 to December 2015 in Qilu Hospital,Shan Dong University.(2)Patients were divided in two ways:COPD with and without bronchiectasis groups,emphysema-predominant group(%LAA-950>9.9%)and non-emphysema-predominant groups(%LAA-950<9.9%).Results:(1)1739 COPD patients were included in the present study and 8.1%were diagnosed with radiological bronchiectasis.Sex-,age-,smoking history-and BMI-balanced COPD(n=804)and non-COPD(n=837)patients were collected via multistage stratified sampling.The proportion of bronchiectasis were 10.3%and 1.2%,respectively(P<0.001).(2)There were less male in the group of subjects with bronchiectasis(72.9%vs 80.4%,P=0.034).Patients with both COPD and bronchiectasis had worse status of nutrition(ALB,P=0.046),more severe airflow obstruction(FEV1%,P<0.001),and more extensive emphysema(%LAA-950,P=0.011)than patients without bronchiectasis.Regarding comorbidities,more patients had pulmonary hypertension(6.4%vs 2.4%,P=0.005)and cor pulmonale(23.6%vs 16.1%,P=0.022)in the coexistence group.(3)There were 787 subjects with measurable El in the present study.Based on the%LAA-950 value,patients were divided into emphysema-predominant group(%LAA-950>9.9%,n=369)and non-emphysema-predominant group(%LAA-950<9.9%,n=418).Subjects in emphysema-predominant group had higher proportion of bronchiectasis(1 6.5%vs 10.3%,P=0.01).(4)The Bhalla score increased with the severity of airflow limitation(r=-0.371,P<0.001)and emphysema(r=0.226,P=0.021).Logistic regression analysis showed that El(OR,1.993;95%CI,1.199-3.313;P=0.008)was significantly related with presence of bronchiectasis in COPD subjects.Conclusions:(1)The proportion of bronchiectasis in COPD was 8.1%,which was significantly higher than in non-COPD patients.(2)COPD patients with concomitant bronchiectasis present poorer lung function and higher risk of complication.(3)The occurrence of bronchiectasis in COPD patients correlates with a higher El from CT scans.The underlying mechanism deserves further investigation.Part Two:The influence of co-existence of COPD and bronchiectasis on the ratio of main pulmonary artery to aorta diameter(PA:A)Objectives:To investigate the influence of co-existence of COPD and bronchiectasis on PA:A ratio.Methods:(1)COPD patients who attended Qilu Hospital of Shandong University from April 2012 to December 2016 were retrospectively reviewed.(2)Patients were divided in two ways:high PA:A ratio group(PA:A>1)and low ratio one(PA:A≤1),COPD with and without bronchiectasis groups.Results:(1)A total of 480 COPD patients were included in present study.There were 95 patients in the high ratio group,and the others in the low ratio one.Subjects with high ratio had lower levels of PaO2(P<0.001),worse nutrition(ALB,P<0.001)and pulmonary function parameters(P<0.01).(2)In this study 168 subjects presented with bronchiectasis,and the other 312 did not.Compared with patients without bronchiectasis,co-existence patients had higher peripheral levels of ESR(P<0.001)and fibrinogen(P=0.006).PA:A ratios(0.95±0.17 vs 0.83±0.15,P<0.001)were greater in patients with bronchiectasis.Co-existence patients with high ratios presented with more severe NT-proBNP(P<0.001)and pulmonary artery pressure of echocardiography(P<0.001).(3)Correlation analysis showed that PA:A ratios increased with the Balla score(r=0.412,P<0.001).Multivariate logistic regression analysis showed that bronchiectasis(OR =3.707;95%Cl =1.888-7.278;P<0.001)correlated with the high PA:A ratio in COPD patients.Conclusions:Bronchiectasis in COPD has been considered to be independently associated with relative pulmonary artery enlargement(PA:A>1).BackgroundAs the main pathology inducing airflow limitation occurring before emphysema,airway remodeling involves disruption of the epithelial barrier,abnormal differentiation of epithelial cells,infiltration of inflammatory cells,extracellular matrix deposition and increased subepithelial vascularity.Although the widespread treatment of COPD has reduced the exacerbations and improved prognoses of the disease,the mechanisms of small airway remodeling have not yet been elucidated and calls for continuous efforts for investigation.Airway basal cells(BCs)function as the progenitors of ciliated and secretory cells.After exposure to stimulus,such as cigarette smoking,the pathological changes involve hyperplasia and abnormal differentiation of BCs.Epithelial-mesenchymal trophic unit(EMTU)consists of epithelial cells,subepithelial structural cells,vessels and nerve fibers.Cells in EMTU regulate each other to maintain homeostasis.Lying at the interface between internal milieu and external environment,BCs are the first barrier to accommodate changes in circumstances.When BCs are damaged,a series of pathological changes in airway wall can be induced by the dysfunctional regulation between BCs and subepithelial structural cells.Restoring the normal function of EMTU will help to improve or delay the pathogenesis of airway remodeling.Trophoblast antigen 2(TROP2)can promote the self-renew of stem cells,and also the growth and invasion of several epidermal tumors.Previous research has shown that TROP2 took part in the proliferation and epithelial-mesenchymal transition of BCs.It plays a key role in airway remodeling of COPD.Despite the pivotal role of BCs on subepithelial cells,the effect of BC TROP2 expression on cross-talk with fibroblasts and endothelial cells has not yet been explored.Part One:The role of TROP2 in airway basal cells of COPD on the regulation of fibroblastsObjectives:To explore the regulation of TROP2 in airway basal cells of COPD on the functions of fibroblasts.Methods:The expression of TROP2 was confirmed in different severities of COPD.The correlations of TROP2 with collagen deposition in small airways were assessed in specimens from human cohorts.Co-culture models of BCs and fibroblasts were performed to investigate the influence of TROP2 expression on the activation of subepithelial cells in vitro.Results:(1)A total of 90 subjects were recruited in this study,including 30 nonsmokers,27 smokers with and 33 without COPD.FEV1%was inversely correlated with TROP2 expression in the cohort(r=-0.499,P<0.01).But TROP2 expression did not increase with the severity of GOLD stages in COPD patients.(2)Increased collagen deposition of small airways was observed in COPD patients,compared with that in controls.The expression of TROP2 positively correlated with collagen deposition in small airways(r=0.614,P<0.01)(3)Scratch assay showed that pcDNA3.1-TROP2 promoted the wound closure of HFL-1.Western blot assay showed that pcDNA3.1-TROP2 also promoted the production of Collagen Ⅰ/Ⅲ,whereas siRNA-TROP2 inhibited the production of Collagen Ⅰ/Ⅲ in firboblasts.(4)Western blot assay showed that the protein levels of pERK1/2 in HFL-1 were not significantly increased when co-cultured with pcDNA3.1-TROP2-BCs.Conclusions:(1)Collagen deposition was significantly enriched in small airways of COPD,and correlated with TROP2 expression.(2)TROP2 may play a key role in airway remodeling of COPD by promoting the wound closure and collagen production of fibroblasts.(3)ERK1/2 pathway might not take part in the regulation of TROP2 in BCs on the functions of fibroblasts.Part Two:The role of TROP2 in airway basal cells of COPD on the regulation of endothelial cellsObjectives:To investigate the regulation of TROP2 in airway BCs of COPD on functions of endothelial cells(HUVEC).Methods:The expression of TROP2 was confirmed in COPD and control subjects.Correlation of TROP2 with vascularity in small airways was performed in human lung tissues.Co-culture models of BCs and HUVEC were established to investigate the influence of TROP2 on the regulation of endothelial cells in vitro.Results:(1)The number of vessels and the percentage of vascularity in the small airways of COPD were increased compared with those in controls(P<0.01 for both comparisons).The expression of TROP2 positively correlated with vascularity(r=0.547,P<0.001 for number of vessels;r=0.518,P<0.001 for percentage of vascular area).(2)TROP2 of BCs promotes wound closure and angiogenesis of HUVEC.(3)It was shown that the expression of VEGFA was increased in pcDNA3.1-TROP2-BCs,whereas decreased in siRNA-TROP2-BCs.Conclusions:(1)Vascularity was significantly enhanced in the small airways of COPD,and correlated with the expression of TROP2.(2)TROP2 may promote the wound closure and tube formation of endothelial cells,facilitating airway remodeling of COPD.(3)VEGFA might participate in the regulation of TROP2 on the functions of HUVEC.