Associate Research Professor

Basic Sciences
Division of Biomedical Engineering Sciences
School of Medicine
Loma Linda University
Loma Linda, CA 92350

Phone:  (909) 558-8373 Ext. 88373
Fax:  (909) 558-4083

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Research Interest

Radiation therapy is used alone or in combination with surgery and chemotherapy in the care and management of nearly all adult and approximately 75% of pediatric patients with central nervous system (CNS) malignancies. High-grade brain tumors are among the most radio-resistant of all cancers. The total radiation dose needed for cure exceeds the tolerance of normal blood vessels. Both the dose response of the vasculature of a cancer being treated and the response of the vasculature in surrounding normal tissues are important parameters. My research focus on investigating response of normal tissues to irradiation, particularly, radiation-induced changes in normal vasculature in the CNS. Currently, there are no highly effective radio-protective drugs available for reducing the normal tissue damage in patients undergoing radiotherapy. One of my research goals is to evaluate an antioxidant compound to protect the normal tissue, including normal vasculature, from radiation-induced damage. This agent can be considered for translational studies to use in radiation therapy as a therapeutic radio-protector. Another research interest is to study the effect of the spaceflight condition on brain, eye and skin. I am very fortunate to be able to participate in a study to determine effects of spaceflight condition on mice that were flown in the Space Shuttle Atlantis (STS-135). Our study provides the first evidence that space flight condition induces oxidative damage that results in mitochondrial apoptosis in retina. This indicates that astronauts may be at increased risk for late retinal degeneration.

Selected Publications

  1. Mao XW, Crapo JD, Mekonnen T, Lindsey N, Martinez P, Gridley DS and Slater JM. Radioprotective Effect of a Metalloporphyrin Compound in Rat Eye Model. Current Eye Res. 34: 62-72, 2009.
  2. Mao XW, Favre C, Fike JR, Kubinova L, Anderson E, Campbell-Beachler M, Jones T, Smith A,  Rightnar S, Nelson GA. High-LET radiation-induced response of microvessels in the hippocampus. Radiat Res. 173:486-493. 2010.
  3. Mao XW, Green LM, Mekonnen T, Lindsey N, Gridley DS. Gene expression analysis of oxidative stress and apoptosis in proton-irradiated rat retina. In Vivo 24: 425-30, 2010.
  4. Gridley DS, Luo-Owen X, Rizvi A, Makinde AY, Pecaut MJ, Mao XW, Slater JM. Low-dose Photon and Simulated Solar Particle Event Proton Effects on Foxp3+ T Regulatory Cells and Other Leukocytes. Tech Can Res Treat 9:637-650, 2010.
  5. Kubínová L, Janáček J, Eržen I, and Mao XW. Measurement of capillary length from 3D images acquired by confocal microscopy using image analysis and stereology. Microsc. Microanal. 16 (Suppl 2), 2010
  6. Gridley DS, Freeman TL, Makinde AY, Wroe AJ, Luo-Owen X, Tian J, Mao XW, Rightnar S, Kennedy AR, Slater JM, Pecaut MJ. Comparison of proton and electron radiation effects on biological responses in liver, spleen and blood. Int J Radiat Biol. 2011 87(12):1173-81.
  7. Mao XW, Mekonnen T, Kennedy AR, and Gridley DS. Differential gene expression profile of oxidative stress-initiated extracellular matrix remodeling in low or high dose-rate photon irradiated skin. Radiat Res. 176:187-197, 2011.
  8. Mao XW, Crapo JD and Gridley DS. Mitochondrial Oxidative Stress-induced Apoptosis and Radioprotection in Proton-irradiated Rat Retina. Radiat Res. 178:118-25, 2012.
  9. Gridley DS, Rizvi A, Makinde AY, Luo-Owen X, Mao XW, Tian J, Slater JM and Pecaut MJ. Space-relevant radiation modifies cytokine profiles, signaling proteins and Foxp3(+) T cells. Int J Radiat Biol 89:26-35, 2013.
  10. Kubinova L, Mao XW, Janacek J. Blood capillary length estimation from 3D microscopic data by image analysis and stereology. Microsc and Microanal, 19(04): 898-906, 2013. doi:10.1017/S1431927613001487.
  11. Gridley DS, Mao XW, Cao JD, Bayeta EJM, and Pecaut MJ. Protracted low-dose radiation priming and response of liver to acute gamma and proton radiation. Free Radical Res. 47:811-20, 2013.
  12. Gridley DS, Mao XW, Stodieck LS, Ferguson VL, Bateman TA, Moldovan M, Cunningham CE, Jones TA, Slater J M, and Pecaut MJ. Changes in thymus and spleen after return from the STS-135 mission in space. PLoS One. 8(9):e75097, 2013.
  13. Mao XW, Pecaut MJ, Stodieck LS, Ferguson VL, Bateman TA, Bouxsein M, Jones TA, Moldovan M, Cunningham CE, Chieu J and Gridley DS. Space Flight Environment Induces Mitochondrial Oxidative Damage in Ocular Tissue. Radiat. Res. 180:340-50, 2013.
  14. Mao XW, Pecaut MJ, Cao JD, Moldovan M, Gridley DS. Low-dose radiation modifies skin response to acute gamma-rays and protons. In Vivo, 27:695-700, 2013.
  15. Mao XW, Pecaut M, Stodieck L, Ferguson V,  Bateman T, Bouxsein M, Gridley D. Biological and Metabolic Response in STS-135 Space-flown Mouse Skin. Free Radical Res. 48:890-7, 2014.
  16. Latchney SE, Rivera PD, Mao XW, Ferguson VL, Bateman TA, Stodieck LS, Nelson GA, Eisch AJ. The effect of spaceflight on mouse olfactory bulb volume, neurogenesis, and cell death indicates the protective effect of novel environment. J Appl Physiol 116:1593-604, 2014.
  17. Gridley DS, Mao XW, Tian T, Cao JD, Perez C, Stodieck LS, Ferguson VLBateman TA, Pecaut MJ. Genetic and Apoptotic Changes in Lungs of Mice Flown on the STS-135 Mission in Space. In vivo, 29;423-434, 2015.
  18. Verma SK, Liu BJ, Gridley DS, Mao XW, Kotha N. Imaging informatics-based system to support animal studies for treating pain in spinal cord injury utilizing proton-beam radiotherapy Proc. SPIE  9418, Medical Imaging 2015: PACS and Imaging Informatics: Next Generation and Innovations, 941811 (March 17, 2015).   doi: 10.1117/12.2081550.
  19. Boerma M, Nelson GA, Sridharan V, Mao XW,  Koturbash I, Hauer-Jensen M. Space radiation and cardiovascular disease risk. World J of Cardiology 2015.
  20. Mao XW, Pecaut MJ, Cao JD, Gridley DS. Effects of targeted proton radiation on spinal cord in a porcine model: a pilot study. In vivo 29: 651-660. 2015