Regenerative Effect of Growth Hormone (GH) in the Retina after Kainic Acid Excitotoxic Damage.

摘要: In addition to its role as an endocrine messenger, growth hormone (GH) also acts a neurotrophic factor in the central nervous system (CNS), whose effects are involved neuroprotection, axonal growth, and synaptogenic modulation. An increasing amount of clinical evidence shows beneficial effect GH treatment patients with brain trauma, stroke, spinal cord injury, impaired cognitive function, neurodegenerative processes. response Muller cells transdifferentiate into neural progenitors proliferate, which constitutes early regenerative process chicken retina. this work, we studied long-term protective after causing severe excitotoxic damage Thus, acute injury was induced via intravitreal injection kainic acid (KA, 20 µg), followed by chronic administration (10 injections [300 ng] over 21 days). Damage provoked disruption several retinal layers. However, KA-damaged retinas treated GH, observed significant restoration inner plexiform layer (IPL, 2.4-fold) nuclear (INL, 1.5-fold) thickness general improvement structure. addition, increase expression genes important pathways, including: markers (DLG1, NRXN1, GAP43); glutamate receptor subunits (NR1 GRIK4); pro-survival factors (BDNF, Bcl-2 TNF-R2); Notch signaling proteins (Notch1 Hes5). Interestingly, cell transdifferentiation (Sox2 FGF2) were upregulated treatment. These results consistent number BrdU-positive retina, administration. Our data suggest that is able facilitate proliferative injured retina enhance regeneration neurite interconnections.