Zde - 2. lékařská fakulta - Univerzita Karlova

P-68. NEUROGENIC AND GLIOGENIC POTENTIAL OF DACH1-EXPRESSING CELLS IN THEROOF OF THE LATERAL VENTRICLE AFTER FOCAL CEREBRAL ISCHEMIAHonsa P. 1,2 , Pivonkova H. 1 , Anderova M. 1,21 Department of Cellular Neurophysiology, Institute of Experimental Medicine ASCR, v.v.i., Prague,Czech Republic; 2 2nd Faculty of Medicine, Charles University, Prague, Czech RepublicSupervisor: Ing. Miroslava Anděrová, PhDIntroduction: The mouse Dach1 gene controls the development of the neocortex and thehippocampus. It is expressed by cortical neural stem cells (NSC) at early stages of neurogenesis, andits expression also continues in certain cell subpopulations in the adult cortex and the hippocampalCA1 region. Interestingly, a subpopulation of Dach1-expressing cells is also present in the roof of thelateral ventricles (LV)and rostral migratory stream (RMS).Aims: In this study we aimed to elucidate the role of mDach1-expressing cells in adult neurogenesisand gliogenesis under physiological as well as post-ischemic conditions.Materials and Methods: We used a transgenic mice in which the expression of green fluorescentprotein (GFP) is controlled by the D6 promotor of mouse Dach1 gene. We isolated GFP-positive(GFP+) cells from the roof of the LV and studied their ability to form neurospheres and differentiate invitro. We also performed immunohistochemical and electrophysiological analysis of GFP+ cells inadult sham-operated brains (control) and in brains after middle cerebral artery occlusion (MCAo),which was used as a model of focal cerebral ischemia.Results: The GFP+ cells isolated from the controls were able to form neurospheres, and afterchanging conditions to adherent culture, they adopted a phenotype resembling that of glial cells, i.e.,they displayed time- and voltage-independent K+ currents and expressed nestin and GFAP. TheGFP+ cells isolated from the brains after MCAo formed larger neurospheres, and subsequently, theyalso differentiated into cells with the current pattern and immunocytochemical properties of neuronalprecursors. Immunohistochemical and electrophysiological analyses performed in control brainsrevealed that the GFP+ cells expressed the phenotype of adult NSC or neuroblasts. The analysis ofGFP+ cells after MCAo revealed a significantly higher number of GFP+ cells expressing doublecortin,a marker of neuroblasts; nevertheless, their electrophysiological properties were comparable withthose observed in controls. Following ischemic injury, more GFP+ cells migrated through the RMS intothe olfactory bulb, where they differentiated into calretinin+ interneurons.Conclusions: Taken together, our results reveal a new region in the roof of the LV where the processof adult neurogenesis takes place. In this region, Dach1-expressing cells exhibit the properties of adultNSC or neuroblasts and respond to ischemia by an increased production of neuroblasts.Support: Supported by GA ČR: GA P303/12/0855, GAUK 383711100