Paracrine-mediated neuroprotection and neuritogenesis of axotomised retinal ganglion cells by human dental pulp stem cells:Comparison with human bone marrow and adipose-derived mesenchymal stem cells

We have investigated and compared the neurotrophic activity of human dental pulp stem cells (hDPSC), human bone marrow-derived mesenchymal stem cells (hBMSC) and human adipose-derived stem cells (hAMSC) on axotomised adult rat retinal ganglion cells (RGC) in vitro in order to evaluate their therapeutic potential for neurodegenerative conditions of RGC. Using the transwell system, RGC survival and length/number of neurites were quantified in coculture with stem cells in the presence or absence of specific Fc-receptor inhibitors to determine the role of NGF, BDNF, NT-3, VEGF, GDNF, PDGF-AA and PDGF-AB/BB in stem cell-mediated RGC neuroprotection and neuritogenesis. Conditioned media, collected from cultured hDPSC/hBMSC/hAMSC, were assayed for the secreted growth factors detailed above using ELISA. PCR array determined the hDPSC, hBMSC and hAMSC expression of genes encoding 84 growth factors and receptors. The results demonstrated that hDPSC promoted significantly more neuroprotection and neuritogenesis of axotomised RGC than either hBMSC or hAMSC, an effect that was neutralized after the addition of specific Fc-receptor inhibitors. hDPSC secreted greater levels of various growth factors including NGF, BDNF and VEGF compared with hBMSC/hAMSC. The PCR array confirmed these findings and identified VGF as a novel potentially therapeutic hDPSC-derived neurotrophic factor (NTF) with significant RGC neuroprotective properties after coculture with axotomised RGC. In conclusion, hDPSC promoted significant multi-factorial paracrine-mediated RGC survival and neurite outgrowth and may be considered a potent and advantageous cell therapy for retinal nerve repair

Individual and group sensitivity to remedial reading program design: examining reading gains across three middle school reading projects

The purpose of this project was to examine group- and individual-level responses by struggling adolescents readers (6(th) – 8(th) grades; N = 155) to three different modalities of the same reading program, Reading Achievement Multi-Component Program (RAMP-UP). The three modalities differ in the combination of reading components (phonological decoding, spelling, fluency, comprehension) that are taught and their organization. Latent change scores were used to examine changes in phonological decoding, fluency, and comprehension for each modality at the group level. In addition, individual students were classified as gainers versus non-gainers (a reading level increase of a year or more vs. less than one year) so that characteristics of gainers and differential sensitivity to instructional modality could be investigated. Findings from both group and individual analyses indicated that reading outcomes were related to modalities of reading instruction. Furthermore, differences in reading gains were seen between students who began treatment with higher reading scores than those with lower reading scores; dependent on modality of treatment. Results, examining group and individual analyses similarities and differences, and the effect the different modalities have on reading outcomes for older struggling readers will be discussed