Drugs of choice used in the treatment of pulmonary hypertension (PH) clearly show that endothelin-1 (ET-1) is a major participant in this fatal disease. Angiotensin (AngII) through its AT1 receptor stimulates the production of ET-1 in human lung vascular endothelial cells (HLVEC). ET-1 then stimulates the production of vasodilating, antiproliferative nitric oxide (NO) and prostacyclin (PGI2) through its ETB receptor in the HLVEC. In human lung vascular smooth muscle cells (HLVSMC) ET-1 stimulates cell proliferation and vasoconstriction. In PH this homeostatic regulation breaks down. The AT1 receptor, which is involved at the initial stage of PH, propagates many of the signals participating in the etiology of PH. Our studies on receptor signaling motifs combined with mutant receptor transfection and signal cascade determinations have enabled us to control the signaling of the AT1 receptor. More recently we can now control signaling by the (wild type) endogenously expressed receptors with the use of cell penetrating peptides constructed to mimic the receptor motifs sequence(s). We intend to achieve signal control in the ETA and ETB receptors and then regulate these signal transductions in human lung vascular endothelial and smooth muscle cells. It is anticipated that this approach will lead to new treatments of PH. Our working hypothesis is that signal cascades involving MAPKs, the Akt/PI3K/PTEN system, small G-protein RhoA and heterotrimeric G- proteins work in various combinations to produce ET-1 through the AT1 receptor and to produce NO and PGI2 through the ETB receptor in human lung vascular endothelial cells and to produce contraction and proliferation through the ETA/ETB receptors in human lung vascular smooth muscle cells;that these signal interactions can be controlled through the use of altered receptors and cell penetrating peptides;and that by altering these signals, we will be able to decrease ET-1 and increase NO and prostacyclin production by endothelial cells and decrease growth and contraction in smooth muscle cells.
Specific aims, 1) a) We will regulate AT1, ETA and ETB receptor signaling through motif identification and mutation construction within the receptor to regulate G1q, G1i, RhoA, Akt and MAPKs. b) We will then regulate signaling in endogenously expressed AT1 and ETB receptors in human lung endothelial cells and ETA receptors in smooth muscle cells with use of membrane permeable peptides. 2) With use of the altered receptors and the peptides developed in SA 1, we will regulate the expression and release of ET-1 by AngII and the release of NO and prostacyclin in the HLVEC by ET-1. These results will then be used to control function of these receptors in HLVEC isolated from lung transplants of individuals with PH. 3) With use of the altered receptors and the peptides developed in Specific Aim 1, we will regulate contraction and proliferation in human lung vascular smooth muscle cells, including cells obtained from individuals with PH. 4) The studies on smooth muscle contraction in culture will be followed up with physiological experiments using rats.
Pulmonary hypertension is a debilitating and mostly fatal disease. Our experiments, including the production of peptides which interfere with negative signals of angiotensin and endothelin, are designed to lead to new approaches which should prove beneficial in the treatment of pulmonary hypertension.
|Wilson, Jamie L; Yu, Jun; Taylor, Linda et al. (2015) Hyperplastic Growth of Pulmonary Artery Smooth Muscle Cells from Subjects with Pulmonary Arterial Hypertension Is Activated through JNK and p38 MAPK. PLoS One 10:e0123662|
|Yao, Chunxiang; Yu, Jun; Taylor, Linda et al. (2015) Protein Expression by Human Pulmonary Artery Smooth Muscle Cells Containing a BMPR2 Mutation and the Action of ET-1 as Determined by Proteomic Mass Spectrometry. Int J Mass Spectrom 378:347-359|
|Yu, Jun; Rupasinghe, Chamila; Wilson, Jamie L et al. (2015) Targeting receptor tyrosine kinases and their downstream signaling with cell-penetrating peptides in human pulmonary artery smooth muscle and endothelial cells. Chem Biol Drug Des 85:586-97|
|Yu, Jun; Wilson, Jamie; Taylor, Linda et al. (2015) DNA microarray and signal transduction analysis in pulmonary artery smooth muscle cells from heritable and idiopathic pulmonary arterial hypertension subjects. J Cell Biochem 116:386-97|
|Wilson, Jamie L; Rupasinghe, Chamila; Usheva, Anny et al. (2015) Modulating the dysregulated migration of pulmonary arterial hypertensive smooth muscle cells with motif mimicking cell permeable peptides. Curr Top Pept Protein Res 16:1-17|
|Green, Daniel S; Rupasinghe, Chamila; Warburton, Rod et al. (2013) A cell permeable peptide targeting the intracellular loop 2 of endothelin B receptor reduces pulmonary hypertension in a hypoxic rat model. PLoS One 8:e81309|
|Yatawara, Achani; Wilson, Jamie L; Taylor, Linda et al. (2013) C-terminus of ETA/ETB receptors regulate endothelin-1 signal transmission. J Pept Sci 19:257-62|
|Yu, Jun; Taylor, Linda; Wilson, Jamie et al. (2013) Altered expression and signal transduction of endothelin-1 receptors in heritable and idiopathic pulmonary arterial hypertension. J Cell Physiol 228:322-9|
|Yu, Jun; Taylor, Linda; Rich, Celeste et al. (2012) Transgenic expression of an altered angiotensin type I AT1 receptor resulting in marked modulation of vascular type I collagen. J Cell Physiol 227:2013-21|
|Wilson, Jamie L; Taylor, Linda; Polgar, Peter (2012) Endothelin-1 activation of ETB receptors leads to a reduced cellular proliferative rate and an increased cellular footprint. Exp Cell Res 318:1125-33|
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