Erick O. Hernandez-Ochoa
Biochemistry and Molecular Biology
108 N. Greene Street
I completed my M.D. degree in 2000 and obtained my Ph.D. degree in Neurophysiology in 2007, both at the National Autonomous University of Mexico.
The knowledge of the physiology and pathophysiology of the human body and mind has been my fascination. During postdoctoral studies (2007-2010) at the laboratory of Dr. Martin F. Schneider, I conducted studies in neurons and skeletal muscle aiming to understand the function of NFATc1, a transcription factor, and S100A1, a calcium-binding protein. I investigated the patterns of electrical activity that control the activation of NFATc1 in sympathetic neurons. This transcription factor regulates many critical functions such as neuronal development, synaptic plasticity and the axonal growth. I also identified a novel mechanism of regulation of the sympathetic nervous system that innervates the heart when the S100A1 is added extracellularly. This form of regulation may occur during or after a heart attack and the accompanying ischemic damage.
In a series of more recent co-authored publications, we were able to clarify the interaction of calmodulin (CaM) and S100A1 signaling at the calcium release channel in skeletal muscle. S100A1 is a physiologically important sensitizer of calcium release to activating signals (both elevated intracellular free calcium concentration and depolarization). During a prolonged elevation of intracellular calcium concentration, CaM overcome S100A1 and inhibits the calcium release channel. Our work indicates that S100A1 and CaM significantly fine-tune the skeletal muscle machinery.
01/2011-present: Research Associate, Department of Biochemistry and Molecular Biology, University of Maryland, School of Medicine.
07/2007-12/2010: Postdoctoral Fellow, Department of Biochemistry and Molecular Biology, University of Maryland, School of Medicine.
05/2004-07/2007: Research Scholar, Department of Biochemistry and Molecular Biology, University of Maryland, School of Medicine.
09/2001-04/2004: Adjunct Assistant Professor, Department of Biochemistry and Molecular Biology, National Autonomous University of Mexico, School of Medicine.
* Neuronal and muscular physiology.
* Calcium signals and voltage-gated ion channels in excitable cells.
* Regulation of calcium signals and excitability in neurons and skeletal muscle.
* Alterations of voltage gated ion channels function and calcium signaling in neurons and muscle.
* Pathophysiology of Diabetes, Denervation and Skeletal Muscle diseases.
Lab Techniques and Equipment:
Ca2+ imaging and confocal microscopy; Electrophysiolgy: current and voltage clamp; heterologous over-expresion of signaling molecules using adenoviral as well as intra-nuclear micro-injection techniques.
Selected Referred Publications
Hernández-Ochoa EO, Robison P, Contreras M, Shen T, Zhiyong Z, Schneider MF. Elevated extracellular glucose and uncontrolled type-1 diabetes enhance NFAT5 signaling and disrupt the transverse tubular network in mouse skeletal muscle. Experimental Biology and Medicine, 2012, June 26. Accepted.
Liu Y, Hernandez-Ochoa EO, Randall WR, Schneider MF. NOX2 dependent ROS is required for HDAC5 nuclear efflux and contributes to HDAC4 nuclear efflux during intense repetitive activity of fast skeletal muscle fiber. Am J Physiol Cell Physiol. 2012 May 30. [Epub ahead of print]
Olojo RO, Hernández-Ochoa EO, Ikemoto N, Schneider MF. Effects of conformational peptide probe DP4 on bidirectional signaling between DHPR and RyR1 calcium channels in voltage-clamped skeletal muscle fibers. Biophys J. 2011 May 18;100(10):2367-77.
Yamaguchi N, Prosser BL, Ghassemi F, Xu L, Pasek DA, Eu JP, Hernández-Ochoa EO, Cannon BR, Wilder PT, Lovering RM, Weber D, Melzer W, Schneider MF, Meissner G. Modulation of sarcoplasmic reticulum Ca2+ release in skeletal muscle expressing ryanodine receptor impaired in regulation by calmodulin and S100A1. Am J Physiol Cell Physiol. 2011 May;300(5):C998-C1012.
Robison P, Hernández-Ochoa EO, Schneider MF. Adherent primary cultures of mouse intercostal muscle fibers for isolated fiber studies. J Biomed Biotechnol. 2011;2011:393740.
Shen T, Liu Y, Contreras M, Hernández-Ochoa EO, Randall WR, Schneider MF. DNA binding sites target nuclear NFATc1 to heterochromatin regions in adult skeletal muscle fibers. Histochem Cell Biol. 2010 Oct;134(4):387-402.
Hernández-Ochoa EO, Prosser BL, Wright NT, Contreras M, Weber DJ, Schneider MF. Augmentation of Cav1 channel current and action potential duration after uptake of S100A1 in sympathetic ganglion neurons. Am J Physiol Cell Physiol. 2009 Oct;297(4):C955-70.
Prosser BL, Hernández-Ochoa EO, Zimmer DB, Schneider MF. The Qgamma component of intra-membrane charge movement is present in mammalian muscle fibres, but suppressed in the absence of S100A1. J Physiol. 2009 Sep 15;587(Pt 18):4523-41.
Hernández-Ochoa EO, García-Ferreiro RE, García DE. G protein activation inhibits gating charge movement in rat sympathetic neurons. Am J Physiol Cell Physiol. 2007 Jun;292(6):C2226-38.
Hernández-Ochoa EO, Contreras M, Cseresnyés Z, Schneider MF. Ca2+ signal summation and NFATc1 nuclear translocation in sympathetic ganglion neurons during repetitive action potentials. Cell Calcium. 2007 Jun;41(6):559-71.
Editorials and Scientific Reviews
Hernández-Ochoa EO, Robison P. Excitation-Contraction Coupling and Excitation-Transcription Coupling in Skeletal Muscle. Biochem Pharmacol 2012, 1:e117. doi:10.4172/2167-0501.1000e117
Hernández-Ochoa EO, Schneider MF. Voltage clamp methods for the study of membrane currents and SR Ca(2+) release in adult skeletal muscle fibres. Prog Biophys Mol Biol. 2012 Apr;108(3):98-118.
Prosser BL, Hernández-Ochoa EO, Schneider MF. S100A1 and calmodulin regulation of ryanodine receptor in striated muscle. Cell Calcium. 2011 Oct;50(4):323-31.
Schneider MF, Hernández-Ochoa EO. Skeletal Muscle Excitation-Contraction coupling, Chapter 57 In Muscle: Fundamental Biology and Mechanisms of Disease. 1st Edition. Hill JA and Olson EN, editors. Academic Press, Elsevier, London UK. 2012.
For a complete list of my publications, please visit: http://www.ncbi.nlm.nih.gov/pubmed?term=Hernandez-Ochoa%20E