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Tibor  Kristian
 

Tibor Kristian Ph.D.

Academic Title: Associate Professor
Primary Appointment: Anesthesiology
tkris001@umaryland.edu
Location: MSTF, 534
Phone: (410) 706-3418

Personal History:

  • M.S.: Biophysics; Univerzita Pavla Jozefa Šafárika, Slovakia
  • Ph.D.: Membrane physiology, Calcium metabolism; Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Slovak Republic
  • Postdoctoral: Brain ischemia; Experimental Brain Research Lab, Lund University, Sweden

Research Interests:

My research is focused on the fundamental mechanisms of acute brain injury and chronic neurodegenerative disorders. Our studies are centered on processes leading to mitochondrial dysfunction and mechanisms of NAD+ catabolism-related pathophysiology.

We generated transgenic animals expressing mitochondrially-targeted yellow fluorescent protein (eYFP) that allows identification of cell-type specific mitochondria in vivo. These mice are used to examine the effect of acute brain injury on neuronal and non-neuronal mitochondria.

Recently we discovered that NAD+ glycohydrolase CD38 is overexpressed in brain tissue following ischemic insult. CD38 shows increased activity and significantly contributes to cellular NAD+ catabolism.

We are testing the neuroprotective effect of compounds that feed into the NAD+ salvage pathway, as well as inhibit the CD38 activity. Furthermore, we are using molecular techniques study the role of metabolites that are generated downstream of NAD+ catabolism in mechanisms of mitochondrial dysfunction following ischemic insult.


Grants & Contracts:

VA Merit Review Award: "NAD+ catabolism and mitochondrial dysfunction in acute neurodegenerative disease"


Publications:

Kristián T, Gunilla G, Siesjö BK.  The influence of acidosis on hyperglycemic brain damage. Journal of Cerebral Blood Flow and Metabolism 1995 15, 78-87.

Kristián T, OuYang Y-B, Siesjö BK.  Calcium-related damage in vivo and in vitro: are different mechanisms involved ? Advances in Neurology 1996 71, 107-118.

Kristián T, Siesjö BK.  Calcium-related damage in ischemia. Life Sciences 1996 59, 357-367.

Kristián T, Siesjö BK.  Calcium in ischemic cell death. Stroke 1998 29, 705-718.

Kristián T, Gertsch J, Bates T, Siesjö BK.  Characteristics of the calcium-triggered mitochondrial permeability transition in non-synaptic brain mitochondria: effect of cyclosporin A and ubiquinone 0. Journal Neurochem 2000 74:1999-2009.

Kristián T, Bernardi P, Siesjo BK (2001) Acidosis promotes the permeability transition in energized mitochondria: Implications for reperfusion injury. J Neurotrauma,18:1059-1074.

Yoshimoto T, Kristián T, Hu B-R, Ouyang Y-B, Siesjo BK (2002) Effect of NXY-059 on secondary mitochondrial dysfunction after transient focal ischemia; comparison with cyclosporin A. Brain Res 932: 99-109.

Kristián T, Weatherby TM, Bates TE, Fiskum G (2002) Heterogeneity of the calcium-induced permeability transition in isolated non-synaptic brain mitochondria. J of Neurochem.83: 1207-1308.

Kristián T (2004) Metabolic stages, mitochondria, and calcium in hypoxic/ischemic brain damage. Cell Calcium 36 : 221-233.

Kristián T, Fiskum G (2004) A Fluorescence-Based Technique for Screening Compounds that Protect Against Damage to Brain Mitochondria. Brain Res Protocols 13:176-182.

Schuh RA, Kristián T, Fiskum G (2005) Calcium-dependent dephosphorylation of brain mitochondrial calcium/cAMP response element binding protein (CREB). J Neurochem 92(2): 388-394.

Kristián T, Hopkins IB, McKenna MC, Fiskum G (2006). Isolation of mitochondria with high respiratory control from primary cultures of          neurons and astrocytes using nitrogen cavitation. J Neurosci Methods 152:136-143.

Chandrasekaran K, Hazelton JL, Wang Y, Fiskum G, Kristián T (2006) Neuron-specific conditional expression of a mitochondrially-targeted fluorescent protein in mice. J Neuroscience, 26:13123-13127.

Kristián T, Pivovarova NB, Fiskum G, Andrews SB (2007): Calcium-induced precipitate formation in brain mitochondria: composition, calcium capacity,      and retention. J Neurochem. 102(4):1346-56.

Hazelton JL, Petrasheuskaya M, Fiskum G, Kristián T.  Cyclophilin D is expressed predominantly in mitochondria of GABA-ergic interneurons. J Neurosci Res. 2009 87(5):1250-1259.

Balan I, Fiskum G, Kristián T. Visualization and quantification of NAD(H) in brain sections by a novel histo-enzymatic nitrotetrazolium blue staining technique. Brain Res. 2010 1316:112-9.

Kristián T.  Isolation of mitochondria from CNS. Current Protocols in Neurosci. 2010 Chapter 7: Unit 7.22.

Kristián T, Balan I, Schuh R, Onken M.  Mitochondrial dysfunction and NAD+ catabolism as mechanisms of cell death and promising targets for neuroprotection. J Neurosci Res 2011 89:1946-55.

Kristián T, Hu BR. Guidelines for using mouse global cerebral ischemia models. Transl. Stroke Res. 2013 4:343-350. 

Owens K, Park JH, Schuh R, Kristián T. Mitochondrial dysfunction and NAD+ metabolism alterations in the pathophysiology of acute brain injury. Transl. Stroke Res. 2013