NR AYAA
AU Arruda-Carvalho,M.; Njaine,B.; Silveira,M.S.; Linden,R.; Chiarini,L.B.
TI Hop/STI1 modulates retinal proliferation and cell death independent of PrPc
QU Biochemical and Biophysical Research Communications 2007 Sep 21; 361(2): 474-80
PT journal article; research support, non-u.s. gov't
AB Hop/STI1 is a co-chaperone adaptor protein for Hsp70/Hsp90 complexes. Hop/STI1 is found extracellularly and modulates cell death and differentiation through interaction with the prion protein (PrPc). Here, we investigated the expression of hop/STI1 and its role upon cell proliferation and cell death in the developing retina. Hop/STI1 is more expressed in developing rat retina than in the mature tissue. Hop/STI1 blocks retinal cell death in the neuroblastic layer (NBL) in a PrPc dependent manner, but failed to protect ganglion cells against axotomy-induced cell death. An antibody raised against hop/STI1 (alpha-STI1) blocked both ganglion cell and NBL cell death independent of PrPc. cAMP/PKA, ERK, PI3K and PKC signaling pathways were not involved in these effects. Hop/STI1 treatment reduced proliferation, while alpha-STI1 increased proliferation in the developing retina, both independent of PrPc. We conclude that hop/STI1 can modulate both proliferation and cell death in the developing retina independent of PrPc.
MH Animals; Animals, Newborn; Antibodies/pharmacology; Cell Death; Cell Proliferation/drug effects; Cytoprotection/drug effects; Gene Expression Regulation, Developmental/drug effects; Heat-Shock Proteins/genetics/*metabolism; Mice; PrPc Proteins/metabolism; Rats; Retina/*cytology/drug effects/embryology; Retinal Ganglion Cells/cytology/drug effects
AD Universidade Federal do Rio de Janeiro (UFRJ), Instituto de Biofisica da UFRJ, Centro de Ciencias da Saude, bloco G, G2-019 Cidade Universitaria, 21941-902, Rio de Janeiro, Brazil.
SP englisch
PO USA