Epigenetic Reprogramming Drives Epithelial Disruption in Chronic Obstructive Pulmonary Disease.

Chronic obstructive pulmonary disease (COPD) remains a major public health challenge that contributes greatly to mortality and morbidity worldwide. Although it has long been recognized that the epithelium is altered in COPD, there has been little focus on targeting it to modify the disease course. Therefore, mechanisms that disrupt epithelial cell function in patients with COPD are poorly understood. In this study, we sought to determine whether epigenetic reprogramming of the cell-cell adhesion molecule E-cadherin, encoded by the CDH1 gene, disrupts epithelial integrity. By reducing these epigenetic marks, we can restore epithelial integrity and rescue alveolar airspace destruction. We used differentiated normal and COPD-derived primary human airway epithelial cells, genetically manipulated mouse tracheal epithelial cells, and mouse and human precision-cut lung slices to assess the effects of epigenetic reprogramming. We show that the loss of CDH1 in COPD is due to increased DNA methylation site at the CDH1 enhancer D through the downregulation of the ten-eleven translocase methylcytosine dioxygenase (TET) enzyme TET1. Increased DNA methylation at the enhancer D region decreases the enrichment of RNA polymerase II binding. Remarkably, treatment of human precision-cut slices derived from patients with COPD with the DNA demethylation agent 5-aza-2'-deoxycytidine decreased cell damage and reduced air space enlargement in the diseased tissue. Here, we present a novel mechanism that targets epigenetic modifications to reverse the tissue remodeling in human COPD lungs and serves as a proof of concept for developing a disease-modifying target.

Microphysiological Models of Lung Epithelium-Alveolar Macrophage Co-Cultures to Study Chronic Lung Disease.

The interactions between immune cells and epithelial cells influence the progression of many respiratory diseases, such as chronic obstructive pulmonary disease (COPD). In vitro models allow for the examination of cells in controlled environments. However, these models lack the complex 3D architecture and vast multicellular interactions between the lung resident cells and infiltrating immune cells that can mediate cellular response to insults. In this study, three complementary microphysiological systems are presented to delineate the effects of cigarette smoke and respiratory disease on the lung epithelium. First, the Transwell system allows the co-culture of pulmonary immune and epithelial cells to evaluate cellular and monolayer phenotypic changes in response to cigarette smoke exposure. Next, the human and mouse precision-cut lung slices system provides a physiologically relevant model to study the effects of chronic insults like cigarette smoke with the dissection of specific interaction of immune cell subtypes within the structurally complex tissue environment. Finally, the lung-on-a-chip model provides an adaptable system for live imaging of polarized epithelial tissues that mimic the in vivo environment of the airways. Using a combination of these models, a complementary approach is provided to better address the intricate mechanisms of lung disease.

Process Improvements Positively Impact the Use of Intravesical Mitomycin C after Transurethral Resection of Nonmuscle Invasive Bladder Cancer in a Large, Urban Urology Practice.

INTRODUCTION: We assessed the rate of intravesical mitomycin C therapy in patients with nonmuscle invasive bladder cancer who underwent transurethral resection of the bladder, as well as the impact of procedural changes governing its use. METHODS: A retrospective review of our bladder cancer database identified patients who underwent transurethral resection of the bladder with mitomycin C therapy during January 2008 to July 2014. Since our mitomycin C protocols were revised during 2013, patients were stratified based on date of service. Patient demographics and data describing mitomycin C use were tabulated. RESULTS: During January 2008 to May 2013, 276 of 737 (37.5%) ideal patients received mitomycin C (not accounting for patients in whom mitomycin C was contraindicated). Conversely 461 of 737 patients (62.5%) did not receive mitomycin C. Shortages of mitomycin C were responsible for nonuse in 18.4% of cases while no specified reason for nonuse was given in 59%. When cases in which mitomycin C use was contraindicated were taken into account, mitomycin C was used in 51.6% overall. After the implementation of new mitomycin C operating procedures, mitomycin C use increased significantly to 76.0% (p <0.001) (accounting for appropriate nonuse). During this period mitomycin C shortages were not responsible for any case in which mitomycin C was not used. CONCLUSIONS: During 2008 to 2013 mitomycin C was not used in a significant proportion of patients who underwent transurethral resection of the bladder. The implementation of a revised protocol governing mitomycin C use significantly and positively impacted mitomycin C use. Importantly, pharmacy shortages no longer contribute to the nonuse of mitomycin C in patients with bladder cancer. These data highlight the impact of continual improvement initiatives on standard clinical practice.