NEUROPROTECTIVE ACTION OF ERYTHROPOIETIN AGAINST CELL DEATH INDUCED BY HYPOXIA IN SH-SY5Y CELLS.

WENKER, SHIRLEY; CHAMORRO MARÍA EUGENIA; VOTA DAIANA; VITTORI DANIELA; NESSE ALCIRA

Buzios

Congreso; First Congress IBRO-LARC of Neurosciences of Latin America, the Caribbean and the Iberian Peninsula; 2008

Sociedad Brasilera de Neurociencias y Comportamiento, Sociedad Argentina de Investigación en Neurociencias, Sociedad Chilena de Neurociencia, Sociedad de Neurociencia del Uruguay

&amp;amp;lt;!-- /* Font Definitions */ @font-face {font-family:TTDA8O00; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} @font-face {font-family:TTE56O00; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-charset:0; mso-generic-font-family:auto; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:3 0 0 0 1 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-US;} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --&amp;amp;gt; Topics: C: Disorders of the Nervous System C1. Aging and Neurodegenerative Disorders C5. Neurotoxicity, Inflammation, Oncology and Neuroprotection   Neuroprotective action of erythropoietin against cell death induced by hypoxia on SHSY5Y cells. Wenker S, Chamorro ME, Vota D, Vittori D, Nesse A. Department of Biological Chemistry, School of Sciences, University of Buenos Aires, Argentina. E-mail: swenker@qb.fcen.uba.ar   OBJECTIVES: On exposure to hypoxia, brain tissue becomes sensitive to cell injury and death, which could cause neurodegenerative outcomes. Erythropoietin (Epo) has emerged as a multifunctional factor that could play a significant role in tissues outside the hematopoietic system. We decided to investigate whether Epo might be able to prevent deleterious effects of hypoxia. METHODS: Human neuroblastoma SH-SY5Y cells exposed to hypoxia were used. Treatments with Epo were made before and after hypoxia injure. Morphological alterations were observed by scanning electron microscopy (SEM). Cell viability was determined by MTT assay. Apoptosis was detected by DNA laddering and by nuclear fluorescence microscopy (Hoechst). Expression of Bcl-2 members was analyzed by RT-PCR. RESULTS: Hypoxia exposure for 16 or 24 h caused morphological changes like lost of neuritogenesis and cell detachment. Under this condition, a significantly reduced cell viability dependent on the exposure-length (H16 71±9%, H24 28±15%; P<0.05 with respect to controls; n=4) and a significant increase in cell apoptosis were detected (H16 35±2% vs. controls P<0.05; n=5). These results are in accordance with cell morphology alterations and membrane blebbing observed by SEM. The effects triggered by hypoxia in this undifferentiated neuroblastoma cell line were totally prevented by a previous treatment with Epo (25 U/ml, 9 h) as shown by data of cell viability: H16 71±7%, E9/H16 100±4%; P<0.05; n=5, and percentage of apoptotic cells: H16 28±1%, E9/H16 7±2%; P<0.001; n=5. A post treatment with Epo up to 48 h after 16 h of hypoxia did not overcome the injures. Cell exposure to hypoxia showed downregulation of RNAm levels of the antiapoptotic member Bcl-xL (RT-PCR) to near 45±12% of the control levels (P<0.05; n=3), while the previous treatment with Epo has the opposite effect (Bcl-xL RNAm: 147±12%; P<0.05). CONCLUSIONS: these results demonstrate that short treatments with Epo could not reverse the damages caused by SH-SY5Y cell cultures under low oxygen condition. However, Epo prevented the apoptosis induced by hypoxia, suggesting a neuroprotective action partially dependent on the modulation of Bcl-xL.