B.S. in Biomedical Engineering, Antioquia School of Engineering & Health Sciences Institute, Colombia, 2003
M.S. in Biology, University of Antioquia, Colombia, 2009
Ph.D. in Physiology, University of Kentucky, Lexington, KY, 2014
I currently have two independent projects funded by NIDCD/NIH and by the Hearing Health Foundation.
The first project studies the molecular machinery involved in the activity-dependent remodeling of the cytoskeleton in the inner ear sensory organelles, which are known as stereocilia. We recently found that the stability of these actin-filled projections depends on the constant influx of calcium through the mechano-electrical transduction (MET) channels that are located at the tips of stereocilia (Velez-Ortega, et al., eLife, 2017). We found that the blockage of MET channels or the breakage of their gating tip links leads to the shortening of stereocilia; but once the blockage is removed or the tip links regenerate, stereocilia are able to regrow. Based on the changes in stereocilia height in response to variations in the resting MET current, I hypothesize that the stereocilia actin cytoskeleton exhibits activity-dependent plasticity. This project constitues the first step in the search for the molecular players involved in this type of cytoskeleton remodeling.
The second project studies the role of TRPA1 channels in the inner ear. TRPA1 is an ion channel mostly known for its role as an "irritant sensor" in pain-sensing neurons. Functional TRPA1 channels are also expressed in the inner ear. However, given that genetically-modified mice lacking TRPA1 channels have normal hearing and balance, the role of these channels in the inner ear remains unknown. Noise exposure leads to the production of some of the cellular "irritants" that activate TRPA1 channels. Therefore, we hypothesized that TRPA1 channels could sense noise-induced damage in the cochlea. When we exposed adult mice to mild noise levels we observed a temporary increase in hearing thresholds that lasted several days. Mice lacking TRPA1 channels, however, recovered significantly faster than mice with normal TRPA1 expression. This project will explore whether, after noise exposure, TRPA1 activation contributes to the temporary shift in hearing thresholds to allow the cochlea enough time to repair or recover from the noise-induced tissue damage.
- 2019/Jan - New Review published in Hearing Research.
- 2018/May - New Grant by the National Institute on Deafness and Other Communication Disorders (NIDCD): R21 Early Career Research Award!
- 2018/Apr - New Grant by the Hearing Health Foundation!
-2017/Nov - New publication in The Hearing Journal.
-2016/Dec - Finalist for the 2016 Kaluza Prizes for Excellence in Graduate Research by the American Society for Cell Biology
- 2016/Nov - New Grant by the American Hearing Research Foundation!
- 2016/May - Postdoctoral spotlight by the UK Office of Biomedical Education
- 2015/Dec - Second Place at the UK College of Medicine Postdoctoral Poster Competition
- Mechanotransduction current is essential for stability of the transducing stereocilia in mammalian auditory hair cells. Vélez-Ortega AC, Freeman MJ, Indzhykulian AA, Grossheim JM, Frolenkov GI. eLife. 2017; 6. PMID: 28350294
- Angular Approach Scanning Ion Conductance Microscopy. Shevchuk A, Tokar S, Gopal S, Sanchez-Alonso JL, Tarasov AI, Vélez-Ortega AC, Chiappini C, Rorsman P, Stevens MM, Gorelik J, Frolenkov GI, Klenerman D, Korchev YE. Biophysical journal. 2016; 110(10):2252-65. PMID: 27224490
- Visualization of Live Cochlear Stereocilia at a Nanoscale Resolution Using Hopping Probe Ion Conductance Microscopy. Vélez-Ortega AC, Frolenkov GI. Methods in molecular biology (Clifton, N.J.). 2016; 1427:203-21. PMID: 27259929
- [Common variable immunodeficiency: Clinical and immunological characterization of patients and homogeneous subgroup definition by means of B lymphocyte subpopulation typing]. Vélez AC, Castaño DM, Gómez RD, Orrego JC, Moncada M, Franco JL. Biomedica : revista del Instituto Nacional de Salud. 2015; 35(1):101-16. PMID: 26148039
- Enhanced generation of suppressor T cells in patients with asthma taking oral contraceptives. Vélez-Ortega AC, Temprano J, Reneer MC, Ellis GI, McCool A, Gardner T, Khosravi M, Marti F. The Journal of asthma : official journal of the Association for the Care of Asthma. 2013; 50(3):223-30. PMID: 23259774
- Generation of induced regulatory T cells from primary human naïve and memory T cells. Ellis GI, Reneer MC, Vélez-Ortega AC, McCool A, Martí F. Journal of visualized experiments : JoVE. 2012; (62). PMID: 22525890
- TRPA1-mediated accumulation of aminoglycosides in mouse cochlear outer hair cells. Stepanyan RS, Indzhykulian AA, Vélez-Ortega AC, Boger ET, Steyger PS, Friedman TB, Frolenkov GI. Journal of the Association for Research in Otolaryngology : JARO. 2011; 12(6):729-40. PMID: 21879401
- Somatic mosaicism caused by monoallelic reversion of a mutation in T cells of a patient with ADA-SCID and the effects of enzyme replacement therapy on the revertant phenotype. Moncada-Vélez M, Vélez-Ortega A, Orrego J, Santisteban I, Jagadeesh J, Olivares M, Olaya N, Hershfield M, Candotti F, Franco J. Scandinavian journal of immunology. 2011; 74(5):471-81. PMID: 21671975
- Peripherally induced human regulatory T cells uncouple Kv1.3 activation from TCR-associated signaling. Reneer MC, Estes DJ, Vélez-Ortega AC, Norris A, Mayer M, Marti F. European journal of immunology. 2011; 41(11):3170-5. PMID: 21834013