Clinical and Administrative Pharmacy, Augusta
Director of Clinical and Experimental Therapeutics (CET)
Associate Professor

Curriculum Vitae

Clinical and Administrative Pharmacy, Augusta


1990-1993: BS, University of Kerala, Kerala, India

1993-1995: MS, University of Kerala, Trivandrum, India

1996-2000: PhD, National Dairy Research Institute (NDRI), Indian Council for Agricultural Research, Karnal, India

2001-2002: Research Associate (Project), Dairy Technology, NDRI, India

2003-2009: Postdoctoral Fellow, Department of Neurosciences, Cleveland Clinic, Cleveland OH

2009-2010: Senior Postdoctoral Fellow, Vascular Biology Center, Medical College of Georgia, Augusta GA

Areas of Expertise

Research Areas: Mechanisms of neuro-vascular injury in retina, diabetic retinopathy and optic neuritis

Opportunities for Collaboration:  Neurovascular diseases of the eye

Honors, Awards, and Achievements

2017: Augusta University Culver Vision Discovery Institute Pilot grant award

2017: Augusta University Extramural Success Award

2014: GRU Culver Vision Discovery Institute Pilot grant Award

2012: STaR (Southern Translational Education and Research Conference) Young Investigator Award

2012: National Eye Institute (NEI)/ Association for Research in Vision and Ophthalmology (ARVO) Travel Award

2005: Young Investigator Enhancement Award, American Society for Neurochemistry

1996-1998: Junior Research Fellowship by the University Grants Council/Council of Scientific and Industrial Research, New Delhi, India

1998-2000: Senior Research Fellowship grant by the University Grants Council/Council of Scientific and Industrial Research, New Delhi, India



Augusta University Culver Vision Discovery Institute, GA

Vascular Biology Center, Augusta University

Charlie Norwood VA medical Center, Augusta GA

Association for Research in Vision and Ophthalmology


Research Interests

Neurovascular degeneration is a common feature of vision disorders such as diabetic retinopathy, optic neuritis and retinopathy of prematurity. Goal of my laboratory is to contribute towards the development of novel therapeutic strategies for these pathologies, through characterizing the mechanisms regulating retinal neurovascular damage. Our current research is focused on investigating the role of polyamine oxidase signaling pathways in causing neurodegeneration and vascular injury in the retina.

  • Mechanisms of neurovascular damage in diabetic retinopathy
  • Neuro-glial and vascular interactions in ischemic retinopathy models
  • Molecular mechanisms causing visual dysfunction in Multiple Sclerosis


Selected Publications

Shosha*, Z. Xu*, S.P Narayanan*, T. Lemtalsi, A. Fouda, M. Rojas, J. Xing, D. J. Fulton, R. W. Caldwell, R.B. Caldwell 2018. Mechanisms of diabetes-induced endothelial cell senescence: Role of Arginase 1, Int. J. Mol. Sci. 2018 Apr 17; 19(4). doi: 10.3390/ijms19041215. * Co-first authors

Patel, Z. Xu, E. Shosha, J. Xing, R.Lucas, R.W. Caldwell R.B. Caldwell, S.P Narayanan 2016. Treatment with polyamine oxidase inhibitor limits hyperoxia-induced      retinal vascular injury in ischemic retinopathy. BBA Molecular Basis of Disease 2016 May 27; 1862(9):1628-1639. doi: 10.1016/j.bbadis.2016.05.020

Shosha, Z. Xu, H. Yokota, R. W. Caldwell, R. B. Caldwell, S.P Narayanan 2016. Deletion of Arginase 2 prevents retinal ganglion cell loss and blocks formation acellular Capillaries after Ischemia/Reperfusion Injury. Cell Death and Disease 2016 Nov 24; 7(11):e2483. doi: 10.1038/cddis.2016.295

B. Caldwell, H. A. Toque, S. P Narayanan, R. W Caldwell 2015. Arginase: an old enzyme with new tricks. Trends Pharmacol Sci. 36(6):395-405.

Patel, S. P Narayanan, W. Zhang, Z. Xu, Sukumari-Ramesh S, Dhandapani K, W. Caldwell, R.B.Caldwell 2014. Activation of the endothelin system mediates pathological angiogenesis during ischemic retinopathy. Am J Pathol Sep 6 (14) 00430-1. doi: 10.1016

P Narayanan*, Z. Xu, N. Putluri, A. Sreekumar, T. Lemtalsi, R. W. Caldwell, R.B. Caldwell. Arginase2 deficiency reduces hyperoxia-induced retinal neurodegeneration through the regulation of polyamine metabolism. Cell Death Dis. 2014 Feb 20;5:e1075 (* corresponding author)

P Narayanan, M. Rojas, J. Suwanpradid, H.T, R. W. Caldwell, R.B. Caldwell. Arginase in Retinopathy. Prog Ret Eye Research 2013 Sep;36:260-80

Yokota, S. P Narayanan, W. Zhang, Z. Xu, L. Yancey, A. Yoshida, D.M Marcus, R.W Caldwell, R.B Caldwell, S.E Brooks. Hyperoxia therapy of pre-proliferative ischemic retinopathy in a mouse model. Invest Ophthalmol Vis Sci. 2011 Aug 11; 52(9):6384.

P Narayanan, J. Suwanpradid, A. Saul, Z. Xu, R. W Caldwell, R.B Caldwell. Arginase2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity, PLosONE. 2011; 6(7): e22460.

Yu, S. P Narayanan, F. Wang, E. Morse, W.B Macklin, N.S Peachey. Visual abnormalities associated with enhanced optic nerve myelination. Brain Res. 2011 Feb 16; 1374:36-42.

P Narayanan, A.I Flores AI, F. Wang and W.B Macklin. Akt sinals through the mammalian target of rapamycin pathway to regulate CNS myelination. J Neurosci. 2009 May 27; 29(21): 6860-70.

I Flores*, S. P Narayanan (*Co-First authors), E.N Morse, H.E Shick, X. Yin, G. Kidd, R.L Avila, D.A Kirschner, W.B Macklin. Constitutively active Akt induces enhanced myelination in the CNS. J Neurosci. 2008 Jul 9; 28(28):7174-83.

Grant Support


NIH/NEI R01 award, 05/1/2018-4/30/2023 (Principal Investigator)
Mechanisms of Neurodegeneration in Diabetic Retinopathy: Role of Spermine Oxidase

VA Merit Review Award, 10/01/2015 – 09/30/2019 (Co-Investigator)
Title: Mechanisms of Traumatic Retinopathy: Role of Arginase


National Multiple Sclerosis Society Pilot grant award, 11/1/2016-1/31/2018 (Principal Investigator)
Title: Role of arginase in Multiple Sclerosis Mediated Retinal Neuronal Injury

American Heart Association Scientist Development Grant 07/01/2011 – 06/30/2015 (Principal Investigator)
Title:  Role of neuronal arginase on vascular protection during ischemic retinopathy

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