Protective effect of heat shock proteins 70.1 and 70.3 on retinal photic injury after systemic hyperthermia.
OBJECTIVE
This study aimed to determine the relationship between the heat shock protein 70 from hsps70.1 and 70.3 on retinal photic injury after systemic hyperthermia.


METHODS
Eight-week-old female C57BU6 mice were kept at a constant temperature of 41-42 degrees C for 25-30 minutes. After dark-adaptation for 8 hours, intense light of 11000 lux was maintained for 6 hours. Histology and immunohistochemistry for the inducible heat shock protein 70 (hsp70), the constitutive heat shock protein 70 (hsc70), and westem blot analysis, reverse transcriptase-polymerase chain reaction for hsp70.1 and hsp70.3 were performed just before photic injury and after 1, 4, 7, and 14 days.


RESULTS
Light-induced retinal degeneration was prevented by thermotolerance. After hyperthermia, hsp70 was densely expressed in the inner segment of the photoreceptor layer on the photic injury. Hsp70 expression increased for 4 days after photic injury and slowly decreased thereafter. mRNA from hsp70.3 was induced earlier than that of hsp70.1.


CONCLUSIONS
Retinal photic injury was prevented by hyperthermia-induced hsp70. Hsp70 from hsp70.3 may be a rapid and short-lived responder, and that from hsp70.1 is a slower and more sustained responder. Hsp70 from hsp70.3 may be an initial retinal chaperone while hsp70 from hsp70.1 may be a sustained chaperone.
Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
Jin Hyoung
JH
Kim
Jeong Hun
JH
Kim
Young Suk
YS
Yu
Seon Mi
SM
Jeong
Kyu-Won
KW
Kim
D000818:Animals; D005260:Female; D005334:Fever / Q000378:metabolism / Q000503:physiopathology*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D066298:In Vitro Techniques; D008027:Light / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D011832:Radiation Injuries / Q000517:prevention & control*; D012160:Retina / Q000528:radiation effects*
D018840:HSP70 Heat-Shock Proteins; C498550:Hsp70.3 protein, mouse; C081884:heat-shock protein 70.1