Distribución del Valor Extremo

Principal investigator:

Michael Courtney, Ph.D., Research manager, Professor of Cell Signaling. Contact information: Molecular Signaling Laboratory, Department of Neurobiology, A.I. Virtanen Institute,

University of Eastern Finland, P.O. Box1627, Neulaniementie 2, FIN-70211Kuopio, Finland. E-mail: [email protected]

Biography:

Michael Courtney (b. 1967) graduated from University of Cam- bridge in 1988 (B.A.), and the University of Dundee in 1991(Ph.D). Postdoctoral fellowships from the Royal Society, Wellcome Trust, Academy of Finland and Sigrid Jusélius Foundation supported his quantitative imaging development and application activities from 1992 in Prof. Karl Åkerman’s laboratory in Åbo Akademi, Turku. After group leader positions at BTK from 1998, he was appointed from 2000 to a position at the A.I. Virtanen Institute, Kuopio and from 2006 to BTK. He has been affiliated with the Cell Imaging Core since its inception, and established and is running the Multi- modal Imaging Unit at Kuopio University. He was appointed to an Academy of Finland Researcher post from 2003-2008, and Profes- sor of Cell Signaling at the University of Kuopio from 2008.

Personnel:

Post-doctoral researchers: Franz Ho Ph.D., Peter Martinsson Ph.D., Minna Tuittila, Ph.D, Olga Vergun Ph.D. Graduate students: Lili Li, B.Sc., Xiaonan Liu, M.Sc., Maykel Lopez-Rodriguez M.Sc., Xijun Wang, M.Sc., Leena Yadav M.Sc. Undergraduate students: Zoher Hoosenally

Description of the project:

Neuronal cells possess a complex architecture consisting of mul- tiple subcellular compartments. Disease states place cells under stressful conditions. The p38 and JNK stress-activated protein kinase pathways are widely accepted to play a significant role in cell death in and outside the nervous system, and drugs directly targeting stress activated protein kinases have been under devel- opment for many years. However, these pathways also contribute to development, differentiation, and even survival and proliferation. This suggests that direct stress-activated protein kinase inhibitors may be of only limited use. In order to exploit the pathways for the development of novel neuroprotective drugs, it will be necessary to elucidate the mechanisms that organise these pathways into pools with neurodegenerative or physiological functions within the complex structure of neuronal cells. Only then can the neurode- generative activities of the pathways be selectively eliminated. It has been suggested that this may help reduce the neuronal death that contributes to neurodegenerative conditions such as Alzheim- er’s and Parkinson’s diseases, increasingly major causes of death, disability and socioeconomic impact in society. Previous studies of the mammalian stress-activated MAPK pathway have revealed the existence of a plethora of upstream regulators competent to recruit this pathway. In particular, proteins with putative scaffold- ing actions have been found. Such components could in principle have a number of effects on the associated upstream regulator, including (i) to potentiate their ability to activate the pathway, (ii) to

restrict accessibility to activators, (iii) to channel the downstream consequence to select targets and (iv) to localise these properties to specific compartments within a cell.

Our lab’s aim is to elucidate how neuronal cells compartmental- ise the endogenous components of the stress-activated protein kinase pathway and how specific stimuli recruit only select com- ponents of these pathways. To achieve this, we focus mainly on 3 areas: i) Signalling between post-synaptic density proteins and neuronal stress-activated protein kinase pathways; ii) Small G-pro- tein signaling pathways regulating stress-activated protein kinases in neurons; iii) Development and implementation of approaches to imaging of intracellular signaling pathways. The mechanisms which maintain selective responsiveness to upstream stimuli and restricted downstream consequences are anticipated to be a fruit- ful source of potential targets for future neuroprotective strategies. Thus we also utilise the information gleaned from studies of neuro- nal signaling mechanisms to develop and evaluate novel neuropro- tective molecules in cooperation with collaborating partners from both the pharmaceutical industry and from academia.

While pursuing these scientific goals, we also implement imaging methodologies. We adapt and establish the use of a wide range of FRET-based probes of cell signaling and multiparameter imag- ing methods. These allow spatiotemporal measurement of several pathways simultaneously in the same cells. We established facilities (physically located within Biocentre Kuopio, www.uef.fi/aivi/muic) to make available to all researchers both live cell high High-Content Analysis (HCA) and as TIR-FRET and TIR-FRAP techniques. • Total Internal Reflection methods exploit the spatially

restricted evanescent wave formed at the interface between media of different refractive indices, thereby surpassing the classical diffraction limits. These methods are ideally suited to measure signaling events and protein turnover at protein complexes in the plasma-membrane proximal zones of living cells, such as the neuronal postsynaptic density.

• The live-cell HCA unit is interfaced with an automated incu- bator and is suitable for high-throughput studies. This is a nationally unique Biocentre Finland (BF) infrastructure plat- form supported by two BF networks. Our group has estab- lished a number of assays permitting application of HCA methods to primary cultured neurons and, most recently, an in vivo model. More details can be found via the links at www.uef.fi/aivi/muic.

Funding:

The Academy of Finland, The EU 6th _{framework STREP “STRESS-}

PROTECT”, the EU 7th _{framework project “MEMOLOAD”, The}

Sigrid Juselius Foundation, The University of Eastern Finland, The Drug Discovery Graduate School and The Molecular Medicine Graduate School.

Collaborators:

Eleanor Coffey and Tassos Papageorgiou (BTK, Åbo Akademi and University of Turku), Christophe Bonny (University of Lausanne and Xigen Pharma AG), Denise Manahan-Vaughan (University of Bo- chum), Mark Spaller (Brown University, Providence, RI), Olli Pen- tikäinen (University of Jyväskylä), Antti Poso (University of Eastern Finland) and Anita Truttman (CHUV, Lausanne University Hospital).

Selected Publications:

Westerlund, N., Zdrojewska, J., Padzik, A. Komulainen, E., Björk- blom, B., Rannikko E., Tararuk, T., Garcia-Frigola, C., Sandholm, J. Nguyen, L., Kallunki, T. Courtney, M.J., Coffey, E.T. (2011) Phos- phorylation of SCG10/stathmin-2 determines multipolar stage exit and neuronal migration rate. Nat. Neurosci. 14:305-13.

Yang H., Courtney, M.J., Martinsson, P., Manahan-Vaughan, D. (2011) LTD is enhanced, depotentiation is inhibited and LTP is un- affected by the application of a selective JNK inhibitor to the hip- pocampus of freely behaving rats. Eur. J. Neurosci., in press. Waetzig, V., Wacker, U., Haeusgen, W., Björkblom, B., Courtney, M.J., Coffey, E.T. and Herdegen, T. (2009) Concurrent protective and destructive signaling of JNK2 in neuroblastoma cells. Cell Sig-

nal. 21, 873-80

Hellwig, C.T., Kohler, B.F., Lehtivarjo A.-K., Dussmann, H., Court- ney, M.J., Prehn, J.H. and Rehm, M. (2008) Real-time analysis of TRAIL/ CHX-induced caspase activities during apoptosis initiation.

J. Biol. Chem. 283, 21676-85.

Björkblom, B., Vainio, J.C., Hongisto, V., Herdegen, T., Courtney, M.J. and Coffey, E.T. (2008) All JNKs can kill but nuclear localiza- tion is critical for neuronal death. J. Biol. Chem. 283, 19704-19713. Hongisto, V., Vainio, J.C., Thompson, R., Courtney, M.J. and Cof- fey, E.T. (2008) The Wnt pool of GSK-3b _{is critical for trophic de-} privation induced neuronal death. Mol. Cell. Biol. 28, 1515-1527. Westerlund, N., Zdrojewska, J., Courtney, M.J. and Coffey, E.T. (2008) SCG10 as a molecular effector of JNK1: Implications for the therapeutic targeting of JNK in nerve regeneration. Expert Opin.

Ther. Targets, 12, 1-13.

Semenova, M.M., Mäki-Hokkonen, A.M.J., Cao, J., Komarovski, V., Forsberg, K.M., Koistinaho, M. Coffey E.T. and Courtney, M.J. (2007) Rho mediates calcium-dependent activation of p38_{α and} subsequent excitotoxic cell death. Nat. Neurosci. 10, 436-443. Tararuk, T., Östman N., Li, W., Björkblom, B., Padzik, A., Zdrojews- ka, J., Hongisto, V., Herdegen, T., Konopka, W., Courtney M.J. and Coffey, E.T. (2006) JNK1 phosphorylation of SCG10 determines microtubule dynamics and axodendritic length. J. Cell Biol. 173, 265-277.

Björkblom, B., Östman, N., Hongisto, V., Komarovski, V., Filén, J., Nyman, T.A., Kallunki, T., Courtney, M.J. and Coffey, E.T. (2005) Constitutively active cytoplasmic JNK1 is a dominant regulator of dendritic architecture; role of MAP2 as an effector. J. Neurosci. 25, 6350-6361.

Cao, J., Viholainen, J.I., Dart, C., Warwick, H.K., Leyland, M.L. and Courtney, M.J. (2005) The nNOS-PSD95 interface - a target for in- hibition of excitotoxic p38 stress-activated protein kinase activation and cell death. J. Cell Biol. 168, 117-126.

Cao, J., Semenova, M.M., Solovyan, V.T., Han, J., Coffey, E.T and Courtney, M.J. (2004) Distinct requirements for p38a _{and JNK} stress-activated protein kinases in different forms of apoptotic neu- ronal death. J. Biol. Chem. 279, 35903-35913.

Solovyan, V.T., Bezvenyuk, Z., Salminen, A., Austin, C.A. and Courtney M.J. (2002) The role of topoisomerase II beta in the exci- sion of DNA loop domains during apoptosis. J. Biol. Chem. 277, 21458-21467.

Coffey, E.T., Smiciene, G., Hongisto, V., Cao, J., Brecht, S., Herd- egen, T. and Courtney, M.J. 2002) JNK2/3 is specifically activated by stress, mediating c-Jun activation, in the presence of consti- tutive JNK1 activity in cerebellar neurons. J. Neurosci. 22, 4335- 4345.

Coffey, E.T., Hongisto, V., Davis, R.J., Dickens, M. and Courtney, M.J. (2000) Dual Roles for c-Jun N-terminal kinase in developmen- tal and stress responses in cerebellar granule neurons. J. Neurosci. 20, 7602-7613.

Courtney, M.J., Åkerman, K.E.O. and Coffey, E.T. (1997)

Neurotrophins protect cultured cerebellar granule neurons against the early phase of cell death by a two-component mechanism. J.

Neurosci. 17, 4201-4211.