Areas of Expertise

• Skeletal muscle growth and atrophy
• Molecular mechanisms
• Selectivity of intracellular proteolysis in erythroid and muscle cells
• Role of proteasomes and ubiquitin
• Spinal cord injury
• Pulmonary hypertension

Education

• B.S., Physics, Rensselaer Polytechnic Institute
• Ph.D., Biophysics, University of Chicago
• Postdoctoral Fellowship, Physiology and Biochemistry, Harvard Medical School

Honors and Awards

• Established Investigator of the American Heart Association
• Irma T. Hirschl Award, Principal Investigator on grants from NIH, NASA and MDA

Research

With Alfred L. Goldberg, Dr. Etlinger discovered non-lysosomal ATP-dependent proteolytic activity, credited by awardees of the 2004 Nobel Prize in chemistry, as the seminal observation revealing the proteasome/ubiquitin system. In subsequent studies, with his students and colleagues, novel factors involved in the regulation of this pathway including a ubiquitin ligase critical to pulmonary arterial hypertension were identified. Dr. Etlinger proposed how myofibrils turnover during muscle growth and atrophy and the roles of calcium, ATP, and beta-adrenergic receptors in these conditions. Finally, he identified modalities to improve recovery from spinal cord injury including beta-agonists, x-irradiation, and inhibitors of glucose toxicity.

Publications

• Zeman RJ, Brown AM, Wen X, et. al. "Tempol, a Superoxide Dismutase Mimetic, Inhibits Wallerian Degeneration Following Spinal Cord Injury by Preventing Glutathione Depletion and Aldose Reductase Activation." Journal of neurotrauma, 41(17-18), (2024) 2186-2198. doi: 10.1089/neu.2024.0137
• Zeman RJ, Wen X, Ouyang N, et. al. "Role of the Polyol Pathway in Locomotor Recovery and Wallerian Degeneration after Spinal Cord Contusion Injury." Neurotrauma reports, 2(1), (2021) 411-423. doi: 10.1089/neur.2021.0018
• Sehgal PB, Westley J, Lerea KM, et. al. "Biomolecular condensates in cell biology and virology: Phase-separated membraneless organelles (MLOs)." Analytical biochemistry, 597(), (2020) 113691. doi: 10.1016/j.ab.2020.113691
• Zeman RJ, Wen X, Moorthy CR, et. al. "Therapeutic target for external beam x-irradiation in experimental spinal cord injury." Journal of neurosurgery. Spine, 32(5), (2020) 649-656. doi: 10.3171/2019.11.SPINE19305
• Murakami K, Etlinger JD. "Role of SMURF1 ubiquitin ligase in BMP receptor trafficking and signaling." Cellular signalling, 54(), (2019) 139-149. doi: 10.1016/j.cellsig.2018.10.015
• Etlinger JD. "An Exciting Couple." Journal of pediatric ophthalmology and strabismus, 55(3), (2018) 149-150. doi: 10.3928/01913913-20180409-04
• Brown A, Nabel A, Oh W, et. al. "Perfusion imaging of spinal cord contusion: injury-induced blockade and partial reversal by β2-agonist treatment in rats." Journal of neurosurgery. Spine, 20(2), (2014) 164-71. doi: 10.3171/2013.10.SPINE13113

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Teaching Responsibilities

• Medical Cell Biology and Anatomy
• Graduate Histology and Graduate Cell Biology
• Dental Histology
• Cell Biology Topics
• Journal Club