Pulmonary microvascular endothelial cells (PMVECs) form contiguous, semi-permeable barriers between the bloodstream and the interstitial space. cAMP generated by plasma membrane-localized adenylyl cyclases (ACs) enhances PMVEC barriers. In contrast, cytosolic cAMP, cGMP, and cUMP generated by exogenous and endogenous soluble cyclases disrupt PMVEC barriers. These observations suggest that cyclic nucleotide signals are highly localized, or compartmentalized, and that near-membrane and cytosolic cAMP, cGMP, and perhaps cUMP signals have opposing effects on endothelial function in the lung microvasculature. The concept of compartmentalized signals implies that feedback networks localized to specific subcellular domains control the kinetics of second messenger signals. However, our understanding of the physiological and pathophysiological implications of localized feedback networks within pulmonary endothelial cells is at best rudimentary. Thus, the overall goal of this project is to determine the spatial and temporal relationships between compartmentalized cAMP signals, PKA-mediated feedback networks, and regulation of mechanical forces in pulmonary endothelial cells. Experiments described in this proposal will for the first time identify where cAMP signals occur in the 3D space of PMVECs, identify important temporal components of cAMP signals, and chart feedback mechanisms contributing to signal localization and kinetics of these signals. In other words, we will provide roadmaps identifying the spatial locations of cAMP signals that are critical for controlling the dynamics of cellular forces. We will then overlay these responses onto PKA activity maps and underlying distributions of A kinase anchoring proteins (AKAPs). As such, successful completion of the studies proposed in this application will identify the spatial and temporal fingerprints of specific cAMP signalosomes that regulate mechanical forces within pulmonary endothelial cells, and thus control endothelial barrier integrity. The spatial and temporal fingerprints will direct future studies aimed at identifying target proteins within these signalosomes, leading to both a better understanding of the molecular mechanisms underlying localized signal transduction and identifying translational targets within signalosomes.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Program Projects (P01)
Project #
Application #
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Program Officer
Xiao, Lei
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of South Alabama
United States
Zip Code
Shokolenko, Inna N; Alexeyev, Mikhail F (2017) Mitochondrial transcription in mammalian cells. Front Biosci (Landmark Ed) 22:835-853
Balczon, Ron; Morrow, K Adam; Zhou, Chun et al. (2017) Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids. FASEB J 31:2785-2796
Spadafora, Domenico; Kozhukhar, Natalia; Alexeyev, Mikhail F (2016) Presequence-Independent Mitochondrial Import of DNA Ligase Facilitates Establishment of Cell Lines with Reduced mtDNA Copy Number. PLoS One 11:e0152705
Jian, Ming-Yuan; Liu, Yanping; Li, Qian et al. (2016) N-cadherin coordinates AMP kinase-mediated lung vascular repair. Am J Physiol Lung Cell Mol Physiol 310:L71-85
Leavesley, Silas J; Walters, Mikayla; Lopez, Carmen et al. (2016) Hyperspectral imaging fluorescence excitation scanning for colon cancer detection. J Biomed Opt 21:104003
Shokolenko, Inna N; Wilson, Glenn L; Alexeyev, Mikhail F (2016) The ""fast"" and the ""slow"" modes of mitochondrial DNA degradation. Mitochondrial DNA A DNA Mapp Seq Anal 27:490-8
Kozhukhar, Natalya; Spadafora, Domenico; Fayzulin, Rafik et al. (2016) The efficiency of the translesion synthesis across abasic sites by mitochondrial DNA polymerase is low in mitochondria of 3T3 cells. Mitochondrial DNA A DNA Mapp Seq Anal 27:4390-4396
Francis, Michael; Xu, Ningyong; Zhou, Chun et al. (2016) Transient Receptor Potential Channel 4 Encodes a Vascular Permeability Defect and High-Frequency Ca(2+) Transients in Severe Pulmonary Arterial Hypertension. Am J Pathol 186:1701-9
Alvarez, Diego F; Housley, Nicole; Koloteva, Anna et al. (2016) Caspase-1 Activation Protects Lung Endothelial Barrier Function during Infection-Induced Stress. Am J Respir Cell Mol Biol 55:500-510
Morrow, K Adam; Ochoa, Cristhiaan D; Balczon, Ron et al. (2016) Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy. Am J Physiol Lung Cell Mol Physiol 310:L337-53

Showing the most recent 10 out of 115 publications