Project description:Treatment strategies of critical nerve injuries involving nerve gaps more than 3 cm are still not optimal. The need for an alternative to the standard autologous nerve grafts has led to the exploration of adipose derived stem cells (ASC) seeded in bioartificial nerve conduits for enhancement of peripheral nerve regeneration. ASC can be differentiated into Schwann cell like cells, which is believed to improve their neurotrophic potency. Nevertheless, the differentiation process requires several weeks and there is no evidence that the cells maintain their differentiated phenotype in vivo. Thus, the present study evaluated the synergistic effect of undifferentiated ASC with exogenously added growth factors in vitro with the aim to improve the neurotrophic potency of undifferentiated ASC through short ex-vivo stimulation with growth factors. The study furthermore provides a comparative in vitro assay of the six well-known neurotrophic factors NGF, GDNF, BDNF, CNTF, NT3 and NT4. ASC were cultured and thus stimulated in the presence of the respective exogenous growth factor for three days and resulting conditioned medium was evaluated in an in vitro axonal outgrowth assay. In addition, also unstimulated ASC’s conditioned medium was tested in combination with the respective exogenous growth factor for the same assay, which was perfomed on dorsal root ganglion (DRG) explants from 10 days old embryonic chicken. DRG explants from most promising conditions were further analyzed for upregulated STAT-3 and GAP-43 by qRT-PCR. Furthermore, also proteomics and phosphoproteomics were performed for ASC and DRG explants using mass spectrometry. The quantity of selected proteins contained in the ASC’s conditioned medium was investigated by ELISA. Combination of ASC’s conditioned medium with growth factors generally resulted in significantly enhanced axonal outgrowth when compared with their control of DRG explants cultured with the respective growth factor only. Specifically, conditioned medium derived from NT3-stimulated as well as ASC’s conditioned medium supplemented with NT3 or BDNF elicited significant axonal outgrowth from DRG explants in contrast to all other experimental conditions. Significant upregulation of STAT-3 and GAP-43 was evidenced for DRG explants grown in NT3-stimulated ASC’s conditioned medium and to a certain extent also for DRG cultured in ASC’s conditioned medium supplemented with NT3.

Project description:We have undertaken a genome-wide study of transcriptional activity in embryonic superior cervical ganglia (SCG) and dorsal root ganglia (DRG) during a time course of neurite outgrowth in vitro. Gene expression observed in these models likely includes both developmental gene expression patterns and regenerative responses to axotomy, which occurs as the result of tissue dissection. Comparison across both models revealed many genes with similar gene expression patterns during neurite outgrowth. These patterns were minimally affected by exposure to the potent inhibitory cue Semaphorin3A, indicating that this extrinsic cue does not exert major effects at the level of nuclear transcription. We also compared our data to several published studies of DRG and SCG gene expression in animal models of regeneration, and found the expression of a large number of genes in common between neurite outgrowth in vitro and regeneration in vivo. Experiment Overall Design: We wished to determine the transcriptional profiles of neurons undergoing neurite outgrowth in vitro. We were particularly interested in finding genes whose expression is generally associated with the process of neurite outgrowth, rather than with cell type-specific effects. Thus, in order to avoid focusing on transcripts unique to one tissue type versus another, we used a comparative strategy to look for effects that were common to two tissue types and therefore more likely to be involved in the general process of neurite outgrowth. While these explants contain multiple cell types, we felt this was preferable to the more disruptive conditions required to dissociate neurons or obtain a pure neuron population. To this end, we monitored gene expression in cultured explants from SCG and DRG using DNA microarrays. We initiated our studies by culturing embryonic day 13 (E13) mouse SCG in vitro and harvesting tissue for RNA isolation at time points from 2 to 65 hours. Time points were selected to detect both fast, short-term responses (2, 5 and 12 hours), as well as sustained, long-term changes (24, 40, and 65 hours). Samples were hybridized to Affymetrix MG-U74v2 A and B microarrays, with RNA from acutely dissected explants serving as a baseline reference. We followed these experiments with a parallel analysis of a more heterogeneous tissue type, the DRG, which is more frequently used than SCG for in vivo studies of neurite regeneration. Cervical and upper thoracic DRG from E12 embryos were cultured with NGF (the same trophic support as in SCG cultures), harvested at time points from 2 to 40 hours, and hybridized to Affymetrix MOE 430A microarrays.

			Action	DRS
	1h_rhoai.raw	Raw
	4h_rhoai.raw	Raw
	Annotated_spectra_EP.zip	Other
	Annotated_spectra_S.zip	Other
	EP1_C1.raw	Raw

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RhoA inhibitor treatment of spinal cord injury: Deep inside mechanism understanding for a better use

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