The overall objective of this application is to understand how autophagy and inflammation, particularly in the context of lung endothelium, are activated in association to control acute lung injury (ALI). The rationale for the study is based on our novel finding that phospholipase C epsilon (PLC?), a bifunctional PLC isoform with primary sites of expression in the lung and heart, acts as a critical regulator of autophagy and inflammation in the lung and that inhibiting autophagy ameliorates LPS-induced lung vascular leak. Our published data and ongoing work show that mechanistic (formerly mammalian) target of rapamycin (MTOR), a known inhibitor of autophagy, also functions as endogenous modulator of EC inflammation. Furthermore, we have identified an important role of PLC? in causing down-regulation of MTOR levels in the lungs of mice challenged with LPS. Based on these findings, we propose to test the hypothesis that activation of endothelial PLC? down-regulates MTOR levels/signaling to induce autophagy in association with inflammation to cause ALI.
Aim 1 will (i) ascertain the role of PLC? in mediating EC autophagy and inflammation, (ii) assess the contribution of autophagy to EC inflammation and apoptosis, (iii) determine the in vivo role of endothelial PLC? in causing lung inflammation and injury, and (iv) address the in vivo role of endothelial PLC? in causing lung autophagy and evaluate the contribution of this event in the mechanism of lung inflammation and injury.
Aim 2 will (i) determine the role of PLC? in suppressing MTOR levels/signaling to cause EC autophagy and inflammation, (ii) determine the in vivo relevance of suppression of endothelial MTOR levels/signaling in causing lung vascular autophagy and inflammatory injury, and (iii) evaluate the therapeutic potential of autophagy inhibition against evolving ALI. These studies will utilize multidisciplinary approaches ranging from biochemical, cellular, and molecular biology to in vivo gene delivery and lung physiology, and take advantage of conditional PLC? and MTOR knockout mice. The creative integration of in vitro and in vivo studies will provide novel insights into the integrated regulation of EC autophagy and inflammation in ALI and may lead to novel therapeutic interventions to control ALI/ARDS.

Public Health Relevance

This project will identify how the two fundamental processes, autophagy and inflammation, are linked in the lung endothelium and collaborate in causing acute lung injury (ALI). Information gained from this study may lead to development of novel therapeutic strategies against ALI and Acute Respiratory Distress Syndrome (ARDS), and possibly against other autophagy/inflammation-associated diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL116632-01A1
Application #
8576134
Study Section
Respiratory Integrative Biology and Translational Research Study Section (RIBT)
Program Officer
Harabin, Andrea L
Project Start
2013-08-01
Project End
2017-03-31
Budget Start
2013-08-01
Budget End
2014-03-31
Support Year
1
Fiscal Year
2013
Total Cost
$361,255
Indirect Cost
$123,255
Name
University of Rochester
Department
Pediatrics
Type
Schools of Dentistry
DUNS #
041294109
City
Rochester
State
NY
Country
United States
Zip Code
14627
Bijli, Kaiser M; Kanter, Bryce G; Minhajuddin, Mohammad et al. (2014) Regulation of endothelial cell inflammation and lung polymorphonuclear lymphocyte infiltration by transglutaminase 2. Shock 42:562-9
Leonard, Antony; Marando, Catherine; Rahman, Arshad et al. (2013) Thrombin selectively engages LIM kinase 1 and slingshot-1L phosphatase to regulate NF-*B activation and endothelial cell inflammation. Am J Physiol Lung Cell Mol Physiol 305:L651-64