Neuroblast proliferation and differentiation of photoreceptors in cocultures of retinal neurons and Muller cells: stimulatory and protective effects of DHA.

SIMON M.V.; ROTSTEIN N.P.; POLITI LE

Bahia Blanca, Buenos Aires

Workshop; Workshop: Neuronal Communication: From Structure to Physiology.; 2008

Sociedad Argentina de Investigacion en Neurociencias

<!-- /* Font Definitions */ @font-face {font-family:Calibri; panose-1:2 15 5 2 2 2 4 3 2 4; mso-font-charset:0; mso-generic-font-family:swiss; mso-font-pitch:variable; mso-font-signature:-1610611985 1073750139 0 0 159 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin-top:0in; margin-right:0in; margin-bottom:10.0pt; margin-left:0in; mso-line-height-alt:8.0pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri; mso-fareast-font-family:Calibri; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:ES-MX;} @page Section1 {size:8.5in 11.0in; margin:1.0in 1.25in 1.0in 1.25in; mso-header-margin:.5in; mso-footer-margin:.5in; mso-paper-source:0;} div.Section1 {page:Section1;} --> Neuroblast proliferation and differentiation of photoreceptors in cocultures of retinal neurons and Muller cells: stimulatory and protective effects of DHA Simón MV, Rotstein NP  y Politi LE. Instituto de Investigaciones Bioquímicas de Bahía Blanca (INIBIBB), CONICET - Universidad Nacional del Sur, Bahía Blanca. The use of Stem Cells (SC) has become a promising strategy to replace neuronal losses during neurodegenerative diseases of the retina. Müller glial cells are potential candidates to behave as SC in the retina; however, the molecular cues and trophic factors that might regulate their proliferation and differentiation into neurons are still unknown. Here we evaluated the potential of Müller glia to generate neuroblasts (NB) and analyzed the protective effects of docosahexaenoic acid (DHA), a lipid molecule involved in photoreceptor (PHR) survival and differentiation. With this purpose, secondary cultures obtained from pure neuronal or glial cultures or from neuro-glial cocultures were seeded in media supplemented or not with serum or DHA. After fixation, multipotent/progenitor markers (nestin, BrdU incorporation) and photoreceptor markers (Crx, opsin) were analyzed by immunocytochemistry. Neuroblasts were absent in secondary cultures obtained from pure cultures of either retinal neurons or Muller cells, and neuronal cells did not survive after reseeding the cultures. However, in the neuro-glial secondary cultures, about 30% of cells expressed Crx and approximately 2% of them were positive for opsin. Furthermore, a small percentage of NB took up BrdU and/ or expressed the stem cell marker nestin. The addition of DHA increased the expression of Crx and opsin up to 60% and 10%, respectively. Moreover, DHA prevented these photoreceptor-like cells from apoptosis and augmented the number of PHRs having long axons. These results suggest that neuron–glia interaction might be necessary for the generation and/or maintenance of NB and that DHA might promote their further survival and differentiation into photoreceptor-like cells.