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A1202 - Inhibition of Cigarette Smoke Induced MMP1 Using a Novel Drug to Prevent Alveolar Tissue Damage
Author Block: J. Sonett1, T. Shiomi2, V. Anguiano1, D. Woode1, M. P. Goldklang3, U. Unachukwa1, R. Xiao4, T. Shiomi1, J. M. D'Armiento5; 1Columbia Presbyterian, New York, NY, United States, 2Pathology, International University for Healthe and Welfare, Narita-shi, Japan, 3Columbia Presbyterian, Demarest, NJ, United States, 4Anesthesiology, Columbia University Medical Center, New York, NY, United States, 5Dept of Medicine, Columbia Univ, New York, NY, United States.
Introduction
Activation of inflammatory signaling pathways, increased expression of matrix metalloproteases and migration of macrophages into the lung are hallmarks of cigarette smoke induced pulmonary diseases such as Chronic Obstructive Pulmonary Disorder (COPD). A large body of literature demonstrates the critical role of several matrix metalloproteinase (MMP) family members in the lung destruction of COPD. MMP-1, a collagenase, is induced by cigarette smoke and is expressed in the pneumocytes of patients with COPD. These MMPs are also active long after smoking cessation, perpetuating further damage. Utilizing a novel high throughput drug screening mechanism our laboratory has identified the ability of Duloxetine, a selective serotonin reuptake inhibitor (SSRI), to block the induction of inflammation and MMP-1 in-vivo and in-vitro mitigating the effects of cigarette smoke.
Methods:
The 4.5 kb full length MMP-1 promoter was linked to luciferase and transfected into HEK cells. Cells were exposed to CSE, which activates the MMP-1 promoter resulting in luciferase reporter expression. The NIH clinical library of compounds was then screened for the ability to block the cigarette smoke induction of MMP-1. These compounds were then validated for their ability to block the inflammatory cascade and induction of other MMPs. Small airway epithelial cells (SAECs) were treated with 5% cigarette smoke extract (CSE) and Duloxetine, with assessment of MMP-1, TLR4, and IL-8 expression levels. In-vivo, rabbits were exposed to cigarette smoke for 16 weeks and Duloxetine was administered via gavage for the last 4 weeks of smoke exposure.
Results:
Three categories of drugs were initially identified in the primary screen. Duloxetine was selected as the lead candidate to further validate. SAECs were treated with 5% CSE, and Duloxetine resulted in decreased MMP-1 expression. Accordingly, the CSE induction of TLR4 and IL-8 were also downregulated with Duloxetine treatment. In-vivo expression of MMP-1 was downregulated in lung tissue as measured by ELISA. Lung morphometry from the smoke exposed rabbits exhibited less smoke-induced destruction as measured through mean linear intercept, demonstrating that Duloxetine attenuated emphysema development in this rabbit model.
Conclusion
Duloxetine through blockade of the SSRI pathway is already used for the treatment of depressive disorders. The data presented here suggests an alternative mechanism through blockade of TLR4 by which Duloxetine blocks the protease and inflammatory changes after cigarette smoke exposure. These studies have successfully identified a novel therapeutic compound for potential use in the COPD.