Keith Pennypacker, Ph.D.

Assoc Professor, College Of Medicine Neurosurgery

Professor, College Of Medicine Molecular Pharmacology & Physiology

Professor, College Of Medicine Neurology

Professor, College Of Medicine Psychiatry And Behavioral Neurosciences

Professor, Cop Dept Of Pharmaceutical Science

College Of Medicine Molecular Pharmacology & Physiology

Professor, Molecular Pharmacology & Physiology, College Of Medicine, University of South Florida

Contact Info 12901 Bruce B. Downs Blvd.
Tampa, FL 33612

Academic Email:

Academic Phone: (813) 974-9913

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  • PHD, Pharmacology, Pennsylvania State University, 1987
  • MS, Neurobiology, Virginia Commonwealth University, 1984
  • BA, Biology, Millersville University, 1982

Interdisciplinary and Emerging Signature Programs

  • Cardiovascular Sciences

Research Interests

  • The lab focuses on the role of the peripheral immune system in ischemic and traumatic brain injury. Novel therapeutic strategies for brain injuries are being investigated by examining signal transduction pathways that enhance the survival of neuronal cells and reduce inflammation.

Recent Publications

  • Pennypacker, KR. Commentary: Different immunological mechanisms govern protection from experimental stroke in young and older mice with recombinant TCR ligand therapy. Frontiers in cellular neuroscience. 8: 339, 2014.
  • Rowe, D.R. Collier, L.A. Seifert, H.A. Chapman, C.B. Leonardo, C.C. Willing, A. E. Pennypacker, K.R. Leukemia inhibitory factor promotes functional recovery and oligodendrocyte survival in rat models of focal ischemia Eur J Neurosci. 40: 3111-3119, 2014.
  • Seifert, HA.Pennypacker, KR. Molecular and cellular immune responses to ischemic brain injury. Translational stroke research. 5(5) : 543-53, 2014.
  • Seifert, HA.Collier, LA.Chapman, CB.Benkovic, SA.Willing, AE.Pennypacker, KR. Pro-Inflammatory Interferon Gamma Signaling is Directly Associated with Stroke Induced Neurodegeneration. Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology. 9(5) : 679-89, 2014.
  • Pennypacker, KR. Targeting the peripheral inflammatory response to stroke: role of the spleen. Translational stroke research. 5(6) : 635-7, 2014.
  • Womble, T.A., Sanberg, P.R., Pennypacker, K.R., Willing, A.E Monocytes are essential for the neuroprotective effect of human cord blood cells following middle cerebral artery occlusion in rat Molec. Cell. Neurosci. : in press, 2014.
  • Lloyd, M.C., Burke, N., Kalantapour,, F., Niesen, M.I., Hall,, A., Pennypacker, K., Citron, B., Pick, C.G., Adams, V., Das, M., Mohapatra, S., Cualing Quantitative morphological and molecular pathology of the human thymus correlate with infant cause of death Technology and Innovation. : in press, 2013.
  • Rowe, DD.Leonardo, CC.Recio, JA.Collier, LA.Willing, AE.Pennypacker, KR. Human Umbilical Cord Blood Cells Protect Oligodendrocytes from Brain Ischemia through Akt Signal Transduction. The Journal of biological chemistry. 287(6) : 4177-87, 2012.
  • Seifert, HA. Leonardo, CC. Hall, AA. Rowe, DD. Collier, LA. Benkovic, SA. Willing, AE. Pennypacker, KR. The spleen contributes to stroke induced neurodegeneration through interferon gamma signaling. Metabolic Brain Disease. 2(27) : 131-41, 2012.
  • Golden, J.E., Shahaduzzaman, M., Wabnitz, A., Green, S., Womble, T.A., Sanberg, P.R., Pennypacker, K.R., Willing, A.E Human umbilical cord blood cells alter blood and spleen cell populations after stroke Translaional Stroke Research. 4(3) : 490-99, 2012.
  • Seifert, H.A., Hall, A.A., Chapman, C.B., Collier, L.A., Willing, A.E., and Pennypacker, K.R A Transient Decrease in Spleen Size Following Stroke Corresponds to Splenocyte Release into Systemic Circulation J. Neuroimmune Pharmacology. 4(7) : 1017-124, 2012.
  • Pennypacker, K.R Peripheral immune response to CNS injury Translational Stroke Research. 3(3) : 305, 2012.
  • Leonardo, C.C., Musso, J., Das, M., Rowe, D.D., Collier, L., Mohapatra, S., Pennypacker., K.R CCL20 is associated with neurodegeneration following experimental traumatic brain injury and promotes cellular toxicity in vitro Translational Stroke Research. 3(3) : 357-63, 2012.
  • Leonardo, CC. Pennypacker, KR. The splenic response to ischemic stroke: What have we learned from rodent models? Translational Stroke Research. 2(3) : 328-38, 2011.
  • Das, M.Leonardo, CC.Rangooni, S.Mohapatra, SS.Mohapatra, S.Pennypacker, KR. Lateral fluid percussion injury of the brain induces CCL20 inflammatory chemokine expression in rats. Journal of neuroinflammation. 8: 148, 2011.
  • Rowe, DD.Leonardo, CC.Hall, AA.Shahaduzzaman, MD.Collier, LA.Willing, AE.Pennypacker, KR. Cord blood administration induces oligodendrocyte survival through alterations in gene expression. Brain research. 1366: 172-88, 2010.
  • Hall, AA. Pennypacker, KR. Implications of immune system in stroke for novel therapeutic approaches Translational Stroke Research. 1(2) : 85-95, 2010.
  • Leonardo, CC.Hall, AA.Collier, LA.Ajmo, CT.Willing, AE.Pennypacker, KR. Human umbilical cord blood cell therapy blocks the morphological change and recruitment of CD11b-expressing, isolectin-binding proinflammatory cells after middle cerebral artery occlusion. Journal of neuroscience research. 88(6) : 1213-22, 2010.
  • Ajmo, JM.Bailey, LA.Howell, MD.Cortez, LK.Pennypacker, KR.Mehta, HN.Morgan, D.Gordon, MN.Gottschall, PE. Abnormal post-translational and extracellular processing of brevican in plaque-bearing mice over-expressing APPsw. Journal of neurochemistry. 113(3) : 784-95, 2010.
  • Cortes-Salva, M.Nguyen, BL.Cuevas, J.Pennypacker, KR.Antilla, JC. Copper-catalyzed guanidinylation of aryl iodides: the formation of N,N'-disubstituted guanidines. Organic letters. 12(6) : 1316-9, 2010.
  • Leonardo, CC.Hall, AA.Collier, LA.Green, SM.Willing, AE.Pennypacker, KR. Administration of a Sigma Receptor Agonist Delays MCAO-Induced Neurodegeneration and White Matter Injury. Translational stroke research. 1(2) : 135-145, 2010.
  • Hall, AA.Herrera, Y.Ajmo, CT.Cuevas, J.Pennypacker, KR. Sigma receptors suppress multiple aspects of microglial activation. Glia. 57(7) : 744-54, 2009.
  • Leonardo, CC.Pennypacker, KR. Neuroinflammation and MMPs: potential therapeutic targets in neonatal hypoxic-ischemic injury. Journal of neuroinflammation. 6: 13, 2009.
  • Ajmo, CT.Collier, LA.Leonardo, CC.Hall, AA.Green, SM.Womble, TA.Cuevas, J.Willing, AE.Pennypacker, KR. Blockade of adrenoreceptors inhibits the splenic response to stroke. Experimental neurology. 218(1) : 47-55, 2009.
  • Hall, AA.Leonardo, CC.Collier, LA.Rowe, DD.Willing, AE.Pennypacker, KR. Delayed treatments for stroke influence neuronal death in rat organotypic slice cultures subjected to oxygen glucose deprivation. Neuroscience. 164(2) : 470-7, 2009.
  • Hall, AA.Guyer, AG.Leonardo, CC.Ajmo, CT.Collier, LA.Willing, AE.Pennypacker, KR. Human umbilical cord blood cells directly suppress ischemic oligodendrocyte cell death. Journal of neuroscience research. 87(2) : 333-41, 2009.
  • Leonardo, CC.Hall, AA.Collier, LA.Gottschall, PE.Pennypacker, KR. Inhibition of gelatinase activity reduces neural injury in an ex vivo model of hypoxia-ischemia. Neuroscience. 160(4) : 755-66, 2009.
  • Leonardo, CC.Eakin, AK.Ajmo, JM.Collier, LA.Pennypacker, KR.Strongin, AY.Gottschall, PE. Delayed administration of a matrix metalloproteinase inhibitor limits progressive brain injury after hypoxia-ischemia in the neonatal rat. Journal of neuroinflammation. 5: 34, 2008.
  • Ajmo, CT.Vernon, DO.Collier, L.Hall, AA.Garbuzova-Davis, S.Willing, A.Pennypacker, KR. The spleen contributes to stroke-induced neurodegeneration. Journal of neuroscience research. 86(10) : 2227-34, 2008.
  • Herrera, Y.Katnik, C.Rodriguez, JD.Hall, AA.Willing, A.Pennypacker, KR.Cuevas, J. Sigma-1 receptor modulation of acid-sensing ion channel a (ASIC1a) and ASIC1a-induced Ca2+ influx in rat cortical neurons. The Journal of pharmacology and experimental therapeutics. 327(2) : 491-502, 2008.
  • Willing, AE.Pennypacker, KR. Alternate approach to understanding the molecular mechanisms of stroke-induced injury. Histology and histopathology. 22(6) : 697-701, 2007.
  • Duckworth, EA.Butler, T.Collier, L.Collier, S.Pennypacker, KR. NF-kappaB protects neurons from ischemic injury after middle cerebral artery occlusion in mice. Brain research. 1088(1) : 167-75, 2006.
  • Vernon, DO.Garbuzova-Davis, S.Desjarlais, T.Singh Rasile, R.Sanberg, PR.Willing, AE.Pennypacker, KR. Reduced Nuclear Factor kappa B activation in dentate gyrus after active avoidance training. Brain research. 1104(1) : 39-44, 2006.
  • Vendrame, M.Gemma, C.Pennypacker, KR.Bickford, PC.Davis Sanberg, C.Sanberg, PR.Willing, AE. Cord blood rescues stroke-induced changes in splenocyte phenotype and function. Experimental neurology. 199(1) : 191-200, 2006.
  • Newcomb, JD.Ajmo, CT.Sanberg, CD.Sanberg, PR.Pennypacker, KR.Willing, AE. Timing of cord blood treatment after experimental stroke determines therapeutic efficacy. Cell transplantation. 15(3) : 213-23, 2006.
  • Ajmo, CT.Vernon, DO.Collier, L.Pennypacker, KR.Cuevas, J. Sigma receptor activation reduces infarct size at 24 hours after permanent middle cerebral artery occlusion in rats. Current neurovascular research. 3(2) : 89-98, 2006.
  • Katnik, C.Guerrero, WR.Pennypacker, KR.Herrera, Y.Cuevas, J. Sigma-1 receptor activation prevents intracellular calcium dysregulation in cortical neurons during in vitro ischemia. The Journal of pharmacology and experimental therapeutics. 319(3) : 1355-65, 2006.
  • Pollock, G.Pennypacker, KR.Mémet, S.Israël, A.Saporta, S. Activation of NF-kappaB in the mouse spinal cord following sciatic nerve transection. Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale. 165(4) : 470-7, 2005.
  • Duckworth, EA.Butler, TL.De Mesquita, D.Collier, SN.Collier, L.Pennypacker, KR. Temporary focal ischemia in the mouse: technical aspects and patterns of Fluoro-Jade evident neurodegeneration. Brain research. 1042(1) : 29-36, 2005.
  • Vendrame, M.Gemma, Mesquita, D.Collier, L.Bickford, PC.Sanberg, CD.Sanberg, PR.Pennypacker, KR.Willing, AE. Anti-inflammatory effects of human cord blood cells in a rat model of stroke. Stem cells and development. 14(5) : 595-604, 2005.
  • Butler, TL.Pennypacker, KR. The transcriptional response to hypoxic insult controlled by FRA-2. Gene expression. 12(2) : 61-7, 2005.
  • Kassed, CA.Butler, TL.Patton, GW.Demesquita, DD.Navidomskis, MT.Mémet, S.Israël, A.Pennypacker, KR. Injury-induced NF-kappaB activation in the hippocampus: implications for neuronal survival. The FASEB journal : official publication of the Federation of American Societies for Experimental Biology. 18(6) : 723-4, 2004.
  • Dickey, CA.De Mesquita, DD.Morgan, D.Pennypacker, KR. Induction of memory-associated immediate early genes by nerve growth factor in rat primary cortical neurons and differentiated mouse Neuro2A cells. Neuroscience letters. 366(1) : 10-4, 2004.
  • Butler, TL.Pennypacker, KR. Temporal and regional expression of Fos-related proteins in response to ischemic injury. Brain research bulletin. 63(1) : 65-73, 2004.
  • Vendrame, M.Cassady, J.Newcomb, J.Butler, T.Pennypacker, KR.Zigova, T.Sanberg, CD.Sanberg, PR.Willing, AE. Infusion of human umbilical cord blood cells in a rat model of stroke dose-dependently rescues behavioral deficits and reduces infarct volume. Stroke; a journal of cerebral circulation. 35(10) : 2390-5, 2004.
  • Butler, TL.Kassed, CA.Pennypacker, KR. Signal transduction and neurosurvival in experimental models of brain injury. Brain research bulletin. 59(5) : 339-51, 2003.
  • Kassed, CA.Butler, TL.Navidomskis, MT.Gordon, MN.Morgan, D.Pennypacker, KR. Mice expressing human mutant presenilin-1 exhibit decreased activation of NF-kappaB p50 in hippocampal neurons after injury. Brain research. Molecular brain research. 110(1) : 152-7, 2003.
  • Pennypacker, KR. Hong, JS. Fos-related antigen Encyclopedia Molecular Medicine. 5: 1319-20, 2002.
  • Kassed, CA.Willing, AE.Garbuzova-Davis, S.Sanberg, PR.Pennypacker, KR. Lack of NF-kappaB p50 exacerbates degeneration of hippocampal neurons after chemical exposure and impairs learning. Experimental neurology. 176(2) : 277-88, 2002.
  • Butler, TL.Kassed, CA.Sanberg, PR.Willing, AE.Pennypacker, KR. Neurodegeneration in the rat hippocampus and striatum after middle cerebral artery occlusion. Brain research. 929(2) : 252-60, 2002.
  • Hakki, A.Pennypacker, K.Eidizadeh, S.Friedman, H.Pross, S. Nicotine inhibition of apoptosis in murine immune cells. Experimental biology and medicine (Maywood, N.J.). 226(10) : 947-53, 2001.
  • Pennypacker, KR.Kassed, CA.Eidizadeh, S.Saporta, S.Sanberg, PR.Willing, AE. NF-kappaB p50 is increased in neurons surviving hippocampal injury. Experimental neurology. 172(2) : 307-19, 2001.
  • O'Callaghan, JP.Miller, DB.Pennypacker, KR. Chronic dopaminergic signaling in the basal ganglia: a damage perspective on kinases and fos-related antigens. Addiction biology. 5(3) : 369-76, 2000.
  • Pennypacker, KR.Kassed, CA.Eidizadeh, S.O'Callaghan, JP. Brain injury: prolonged induction of transcription factors. Acta neurobiologiae experimentalis. 60(4) : 515-30, 2000.
  • Pennypacker, KR.Yang, X.Gordon, MN.Benkovic, S.Miller, D.O'Callaghan, JP. Long-term induction of Fos-related antigen-2 after methamphetamine-, methylenedioxymethamphetamine-, 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine- and trimethyltin-induced brain injury. Neuroscience. 101(4) : 913-9, 2000.
  • Pennypacker, KR.Eidizadeh, S.Kassed, CA.O'Callaghan, JP.Sanberg, PR.Willing, AE. Expression of fos-related antigen-2 in rat hippocampus after middle cerebral arterial occlusion. Neuroscience letters. 289(1) : 1-4, 2000.
  • Pennypacker, KR.Hernandez, H.Benkovic, S.Morgan, DG.Willing, AE.Sanberg, PR. Induction of presenilins in the rat brain after middle cerebral arterial occlusion. Brain research bulletin. 48(5) : 539-43, 1999.
  • Bruccoleri, A.Pennypacker, KR.Harry, GJ. Effect of dexamethasone on elevated cytokine mRNA levels in chemical-induced hippocampal injury. Journal of neuroscience research. 57(6) : 916-26, 1999.
  • Xiao, Y.Harry, GJ.Pennypacker, KR. Expression of AP-1 transcription factors in rat hippocampus and cerebellum after trimethyltin neurotoxicity. Neurotoxicology. 20(5) : 761-6, 1999.
  • Pennypacker, KR.Fuldner, R.Xu, R.Hernandez, H.Dawbarn, D.Mehta, N.Perez-Tur, J.Baker, M.Hutton, M. Cloning and characterization of the presenilin-2 gene promoter. Brain research. Molecular brain research. 56(1-2) : 57-65, 1998.
  • Pennypacker, K. AP-1 transcription factors: short- and long-term modulators of gene expression in the brain. International review of neurobiology. 42: 169-97, 1998.
  • Pennypacker, K. Transcription factors in brain injury. Histology and histopathology. 12(4) : 1125-33, 1997.
  • Pennypacker, KR.Xiao, Y.Xu, RH.Harry, GJ. Lead-induced developmental changes in AP-1 DNA binding in rat brain. International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience. 15(3) : 321-8, 1997.
  • McMillian, MK.Pennypacker, KR.Thai, L.Wu, GC.Suh, HH.Simmons, KL.Hudson, PM.Sawin, SB.Hong, JS. Dexamethasone and forskolin synergistically increase [Met5]enkephalin accumulation in mixed brain cell cultures. Brain research. 730(1-2) : 67-74, 1996.
  • Bing, G.McMillian, M.Kim, H.Pennypacker, K.Feng, Z.Qi, Q.Kong, LY.Iadarola, M.Hong, JS. Long-term expression of the 35,000 mol. wt fos-related antigen in rat brain after kainic acid treatment. Neuroscience. 73(4) : 1159-74, 1996.
  • Blazka, ME.Bruccoleri, A.Simeonova, PP.Germolec, DR.Pennypacker, KR.Luster, MI. Acetaminophen-induced hepatotoxicity is associated with early changes in AP-1 DNA binding activity. Research communications in molecular pathology and pharmacology. 92(3) : 259-73, 1996.
  • Pennypacker, KR.Hong, JS.Mullis, SB.Hudson, PM.McMillian, MK. Transcription factors in primary glial cultures: changes with neuronal interactions. Brain research. Molecular brain research. 37(1-2) : 224-30, 1996.
  • Pérez-Otano, I.McMillian, MK.Chen, J.Bing, G.Hong, JS.Pennypacker, KR. Induction of NF-kB-like transcription factors in brain areas susceptible to kainate toxicity. Glia. 16(4) : 306-15, 1996.
  • Blazka, M. Germolec, DR. Simeonova, P. Bruccoleri, A. Pennypacker, KR. Luster, MI. Acetomeinophen-induced hepatotxicity is associated with early changes in NF-kB and NF-IL6 DNA binding actvity. J Inflammation. 47(3) : 138-50, 1996.
  • Bronstein, DM.Pennypacker, KR.Lee, H.Hong, JS. Methamphetamine-induced changes in AP-1 binding and dynorphin in the striatum: correlated, not causally related events? Biological signals. 5(6) : 317-33, 1996.
  • Kim, HC.Pennypacker, KR.Bing, G.Bronstein, D.McMillian, MK.Hong, JS. The effects of dextromethorphan on kainic acid-induced seizures in the rat. Neurotoxicology. 17(2) : 375-85, 1996.
  • Pennypacker, KR.Lennard, DE.Hudson, PM.Hong, JS.McMillian, MK. Basal expression of 35 kDa fos-related antigen in olfactory bulb. Brain research. Molecular brain research. 34(1) : 161-5, 1995.
  • Pennypacker, KR.Hong, JS.McMillian, MK. Implications of prolonged expression of Fos-related antigens. Trends in pharmacological sciences. 16(9) : 317-21, 1995.

Positions Held

  • Associate Professor (Department of Pharmacology, College of Medicine, University of South Florida 2001 - 2007)


  • USF Biotechnology Award (University of South Florida - 2006)
  • Grasso Award (Association of Medical Science Graduate Students - 2005)