Long-chain polyunsaturated omega-3 fatty acids, such as docosahexaenoic acid (DHA) with a 22-carbon chain, are found abundantly in oily fish including anchovy, herring, mackerel, and salmon. These omega-3 fatty acids are widely thought to have multiple health-promoting effects. Evidence suggests that DHA decreases blood pressure, especially in hypertensive patients. We hypothesize that the hypotensive action of DHA is mediated by its stimulatory effect on large-conductance calcium and voltage-gated potassium (Slo1 BK) channels important in blood pressure regulation. The research program proposed here will provide molecular and atomic basis of the hypotensive action of DHA involving Slo1 BK channels using a variety of methods. We postulate that a hydrogen bond between a tyrosine residue in the S6 segment of the channel and the carboxylate group is critical in destabilizing the closed conformation of the ion conduction gate and this interaction underlies the hypertensive action. Using the physicochemical principles elucidated, we will rationally design, synthesize and test fatty-acid activators of Slo1 BK channels. The anticipated outcome of the research program has potential to explain blood pressure regulation based on the hydrogen bonds formed between specific tyrosine residues of the Slo1 BK channel and DHA and provide a solid mechanistic foundation for discovery and development of pharmaceuticals and nutraceuticals for blood pressure management.

Public Health Relevance

Omega-3 fatty acids are found at high levels in oily fish such as anchovy, herring, mackerel, and salmon and thus these fatty acids are often referred to as ?fish oils?. We will elucidate physical and chemical mechanisms by which omega-3 fatty acids regulate ion channel proteins involved in cell excitation at an atomic level and compare how whole animals respond to acute treatments with omega-3 fatty acids. The anticipated outcome of the research program will advance our understanding of the health protective roles of fish oils.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM121375-04S1
Application #
10134062
Study Section
Biophysics of Neural Systems Study Section (BPNS)
Program Officer
Nie, Zhongzhen
Project Start
2017-06-01
Project End
2021-04-30
Budget Start
2020-05-01
Budget End
2021-04-30
Support Year
4
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Physiology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Gessner, Guido; Sahoo, Nirakar; Swain, Sandip M et al. (2017) CO-independent modification of K+ channels by tricarbonyldichlororuthenium(II) dimer (CORM-2). Eur J Pharmacol 815:33-41