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.
- Peixoto-Neves D, Wang Q, Leal-Cardoso JH, Rossoni LV, Jaggar JH. Eugenol dilates mesenteric arteries and reduces systemic blood pressure by activating endothelial cell TRPV4 channels. Br J Pharmacol. 2015 Apr 1. doi: 10.1111/bph.13156. [Epub ahead of print] PubMed PMID: 25832173.
- Burris SK, Wang Q, Bulley S, Neeb ZP, Jaggar JH. 9-Phenanthrol inhibits recombinant and arterial myocyte TMEM16A channels. Br J Pharmacol. 2015 May;172(10):2459-68. doi: 10.1111/bph.13077. Epub 2015 Mar 24. PubMed PMID: 25573456.
- Sullivan MN, Gonzales AL, Pires PW, Bruhl A, Leo MD, Li W, Oulidi A, Boop FA, Feng Y, Jaggar JH, Welsh DG, Earley S. Localized TRPA1 channel Ca2+ signals stimulated by reactive oxygen species promote cerebral artery dilation. Sci Signal. 2015 Jan 6;8(358):ra2. doi: 10.1126/scisignal.2005659. PubMed PMID: 25564678.
- Samak G, Chaudhry KK, Gangwar R, Narayanan D, Jaggar JH, Rao R. Calcium/Ask1/MKK7/JNK2/c-Src signalling cascade mediates disruption of intestinal epithelial tight junctions by dextran sulfate sodium. Biochem J. 2015 Feb 1;465(3):503-15. doi: 10.1042/BJ20140450. PubMed PMID: 25377781; PubMed Central PMCID: PMC4385020.
- Nnorom CC, Davis C, Fedinec AL, Howell K, Jaggar JH, Parfenova H, Pourcyrous M, Leffler CW. Contributions of KATP and KCa channels to cerebral arteriolar dilation to hypercapnia in neonatal brain. Physiol Rep. 2014 Aug 28;2(8). pii: e12127. doi: 10.14814/phy2.12127. Print 2014 Aug 1. PubMed PMID: 25168876; PubMed Central PMCID: PMC4246596.
- Nourian Z, Li M, Leo MD, Jaggar JH, Braun AP, Hill MA. Large conductance Ca2+-activated K+ channel (BKCa) α-subunit splice variants in resistance arteries from rat cerebral and skeletal muscle vasculature. PLoS One. 2014 Jun 12;9(6):e98863. doi: 10.1371/journal.pone.0098863. eCollection 2014. PubMed PMID: 24921651; PubMed Central PMCID: PMC4055454.