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Selected Publication:
Trattnig, C.
The role of miR-451 in neuronal differentiation in vitro
Doktoratsstudium der Medizinischen Wissenschaft; Humanmedizin; [ Dissertation ] Graz Medical University; 2015. pp.172.
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- Authors Med Uni Graz:
- Maurer Christa
- Advisor:
- Leitinger Gerd
- Patz Silke
- Schäfer Ute
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- Abstract:
- Micro-RNAs (miRNA, miR) are small, endogenous noncoding RNA molecules, which regulate gene expression post-transcriptionally. miR-451 is present in microparticles (MPs) isolated from cerebrospinal fluid (CSF) of traumatic brain injured (TBI) patients and not in MPs derived from CSF of non-injured controls. Uptake of MPs derived from CSF of TBI patients by human NT2 cells in vitro results in a miR-451 specific down-regulation of FGFR1 (Fibroblast growth factor receptor 1) and CD133 (Prominin-1) expression. These factors are linked to injury induced neurogenesis. High cerebral miR-451 levels might regulate neurogenic processes and could be associated to more mature differentiation states. We hypothesise that miR-451 plays a role in the induction of neurogenesis. The aim of this dissertation is to analyse the role of miR-451 during neuronal differentiation of NT2 (Ntera-2 cl.D1) cells in vitro. NT2 cells were transduced with a miR-451 overexpression and control vector using lentiviruses. Neuronal differentiation was induced by addition of retinoic acid in free floating aggregates (neurospheres) and mitotic inhibitor in adherent neurospheres. Cell migration and development was monitored at different developmental time points using CellIQ and qRT-PCR; miRNA expression was examined using qRT-PCR; immunofluorescence was performed to visualize neuronal extensions; target genes were validated by qRT-PCR and western blot. Expression levels of miR-451 significantly increase during later stages of neuronal differentiation in NT2 cells. Neurite outgrowth from NT2 neurospheres and mobility of precursor cells was significantly enhanced in miR-451 overexpressing cells. Delay of gap closure in scratch assays in undifferentiated miR-451+ cells, increased miR-451 expression levels during neuronal differentiation in vitro, enhanced elongation of miR-451 overexpressing migrating cells and augmented outgrowth of neurites during neuronal differentiation indicate a role of miR-451 in neurogenic maturation processes in vitro. Furthermore we succeeded in validating AKT1, CAB39, RAB14, TSC1 und YWHAZ as target genes for miR-451 via qRT-PCR.