Primary (essential) hypertension affects 28 % of the adult population in the United States and leads to premature cardiovascular, cerebrovascular and renal disease. The overall goal of Project #2 is to understand the interactions among the major renal Na+ regulatory pathways (dopamine 1, [DIR], dopamine 3 [DSR], and angiotensin type 1 [ATIR] receptors) which are critical to the regulation of blood pressure in humans. In experimental animals, the renal renin-angiotensin system and the renal dopaminergic system independently, and in concert, regulate renal Na-i- excretion, and defects in these pathways can lead to hypertension. We have reported that the hypertension in mice overexpressing the human G protein-coupled receptor kinase type 4 variant, GRK4 A142V is associated with decreased renal Dl R expression and function and increased ATI R expression and function A similar mechanism may be operating in human essential hypertension. Expression of GRK4 variants in cell lines replicates the Dl R defect noted in human renal proximal tubule cells from hypertensive subjects. Inhibition of GRK4 function or expression normalizes DIR function in human renal proximal tubule cells/cell lines expressing GRK4 variants. Moreover, renal selective prevention of the expression of GRK4 in spontaneously hypertensive rats attenuates the development of hypertension. The uncoupling of Dl R in hypertension impairs the inhibitory paracrine regulation by dopamine (DA) of renal Na+ transport in the proximal tubule and even more distal nephron segments. Because DA, via DiRs and D3Rs, normally antagonizes the increase in Na+ reabsorption caused by angiotensin II, via ATlRs, enhanced renal Na-i- reabsorption In hypertension may be due to an unopposed ATI R action (by DA). The overall hypothesis of Project #2 is that ATI R-mediated antinatriuresis is opposed by D1Rs and D3Rs, acting in concert in normal human subjects, and that this protective mechanism is deficient in patients with essential hypertension.
Three specific aims will determine the interactions among DiRs and D3Rs and ATlRs and their consequences in terms of Na+ excretion: (1) to test the hypothesis that D3R activation induces natriuresis, in part, (continued on next page)

Public Health Relevance

These studies will provide clinical correlation with the biochemical findings of projects 1 and 3 on the genetic causes of human essential hypertension. Understanding the overall physiologic mechanisms that control blood pressure and sustain hypertension can aid in focusing research efforts into successful targeted therapeutic stratagies.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL074940-09
Application #
8399067
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
Project End
Budget Start
2013-01-01
Budget End
2013-12-31
Support Year
9
Fiscal Year
2013
Total Cost
$420,242
Indirect Cost
$84,633
Name
University of Virginia
Department
Type
DUNS #
065391526
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Wang, Zheng; Zeng, Chunyu; Villar, Van Anthony M et al. (2016) Human GRK4γ142V Variant Promotes Angiotensin II Type I Receptor-Mediated Hypertension via Renal Histone Deacetylase Type 1 Inhibition. Hypertension 67:325-34
Jose, Pedro A; Yang, Zhiwei; Zeng, Chunyu et al. (2016) The importance of the gastrorenal axis in the control of body sodium homeostasis. Exp Physiol 101:465-70
Sanada, H; Yoneda, M; Yatabe, J et al. (2016) Common variants of the G protein-coupled receptor type 4 are associated with human essential hypertension and predict the blood pressure response to angiotensin receptor blockade. Pharmacogenomics J 16:3-9
Jose, Pedro A; Felder, Robin A; Yang, Zhiwei et al. (2016) Gastrorenal Axis. Hypertension 67:1056-63
Zhang, Yanrong; Jiang, Xiaoliang; Qin, Chuan et al. (2016) Dopamine D2 receptors' effects on renal inflammation are mediated by regulation of PP2A function. Am J Physiol Renal Physiol 310:F128-34
Konkalmatt, Prasad R; Asico, Laureano D; Zhang, Yanrong et al. (2016) Renal rescue of dopamine D2 receptor function reverses renal injury and high blood pressure. JCI Insight 1:
Carey, Robert M (2016) Resistant Hypertension: Mineralocorticoid Receptor Antagonist or Renal Denervation? Hypertension 67:278-80
Jose, Pedro A (2016) Gastrorenal communication: sniffing and tasting. Exp Physiol 101:457-8
Yang, S; Yang, Y; Yu, P et al. (2015) Dopamine D1 and D5 receptors differentially regulate oxidative stress through paraoxonase 2 in kidney cells. Free Radic Res 49:397-410
Wang, Zhen; Guan, Weiwei; Han, Yu et al. (2015) Stimulation of Dopamine D3 Receptor Attenuates Renal Ischemia-Reperfusion Injury via Increased Linkage With Gα12. Transplantation 99:2274-84

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