Jonathan H. Jaggar, Ph.D.
Maury Bronstein Professor
Department of Physiology
The University of Tennessee Health Science Center
894 Union Avenue
Memphis, TN 38163
Phone: (901) 448-1208
Office: 402 Nash Research Building
Email: Jonathan H. Jaggar
- Ph.D. Institution: University of Sheffield, United Kingdom
Arterial diameter, a primary determinant of systemic blood pressure, is regulated by the contractile state of smooth muscle cells in the arterial wall. One critical regulator of smooth muscle contractility is the intracellular calcium ion concentration. Smooth muscle cells control intracellular calcium concentration by regulating cellular influx, release, sequestration and extrusion. Since membrane potential regulates calcium entry in smooth muscle cells, ion channels that modulate membrane potential also change cellular contractility. Recent studies have discovered that local and global elevations in cytosolic calcium occur in smooth muscle cells. These different calcium signaling events not only regulate contractility, but may also regulate a number of other physiological functions. We are currently investigating sarcolemma ion channels that control membrane potential and calcium entry in arterial smooth muscle cells and the properties, physiological targets, and regulation of arterial diameter by different intracellullar calcium signals. Research in the laboratory involves a multi-faceted approach, studying events at molecular, cellular and intact artery levels. Techniques include patch clamp electrophysiology, rapid confocal calcium imaging, conventional calcium imaging, diameter measurement of pressurized arteries, and molecular biology.
- Bulley S, Jaggar JH. Now you see it, now you don't: the changing face of endothelin-1 signalling during vascular ontogenesis. J Physiol. 2016 Sep 1;594(17):4703-4. doi: 10.1113/JP272564. PubMed PMID: 27581564; PubMed Central PMCID: PMC5009770.
- Wang Q, Leo MD, Narayanan D, Kuruvilla KP, Jaggar JH. Local coupling of TRPC6 to ANO1/TMEM16A channels in smooth muscle cells amplifies vasoconstriction in cerebral arteries. Am J Physiol Cell Physiol. 2016 Jun 1;310(11):C1001-9. doi: 10.1152/ajpcell.00092.2016. PubMed PMID: 27147559; PubMed Central PMCID: PMC4935199.
- Bannister JP, Bulley S, Leo MD, Kidd MW, Jaggar JH. Rab25 influences functional Cav1.2 channel surface expression in arterial smooth muscle cells. Am J Physiol Cell Physiol. 2016 Jun 1;310(11):C885-93. doi: 10.1152/ajpcell.00345.2015. PubMed PMID: 27076616; PubMed Central PMCID: PMC4935198.
- Kidd MW, Leo MD, Bannister JP, Jaggar JH. Intravascular pressure enhances the abundance of functional Kv1.5 channels at the surface of arterial smooth muscle cells. Sci Signal. 2015 Aug 18;8(390):ra83. doi: 10.1126/scisignal.aac5128. PubMed PMID: 26286025.
- Leo MD, Bulley S, Bannister JP, Kuruvilla KP, Narayanan D, Jaggar JH. Angiotensin II stimulates internalization and degradation of arterial myocyte plasma membrane BK channels to induce vasoconstriction. Am J Physiol Cell Physiol. 2015 Sep 15;309(6):C392-402. doi: 10.1152/ajpcell.00127.2015. PubMed PMID: 26179602; PubMed Central PMCID: PMC4572372.
- Peixoto-Neves D, Wang Q, Leal-Cardoso JH, Rossoni LV, Jaggar JH. Eugenol dilates mesenteric arteries and reduces systemic BP by activating endothelial cell TRPV4 channels. Br J Pharmacol. 2015 Jul;172(14):3484-94. doi: 10.1111/bph.13156. PubMed PMID: 25832173; PubMed Central PMCID: PMC4507154.