Impaired repair ability of hsp70.1 KO mouse after UVB irradiation.
UV light is absorbed in the epidermis and induces sunburn cell formation. It has been reported that HSP70 increases the UVB resistance of cell lines by in vitro experiments using various cell lines. In this study, hsp70.1(-/-) KO mouse was used in order to study the role of HSP70 after UVB irradiation. Western blotting showed a decreased level of HSP70 in hsp70.1(-/-) KO mouse compared with wild type FVB mouse. Six h after UVB irradiation, there were no significant histologic differences between the hsp70.1(-/-) KO mouse and the wild type FVB mouse. A similar degree of nuclear swelling was observed. However, there were significant differences at 12 and 24 h after UVB irradiation. After 12 h, a few apoptotic cells were observed in the wild type mouse, but a large number of cells were apoptotic in the hsp70.1(-/-) KO mouse. After 24 h, the epidermis of the wild type FVB mouse was relatively intact, but almost the entire epidermis was necrotic in the hsp70.1(-/-) KO mouse. These results showed that epidermal injury of hsp70.1(-/-) KO mouse was much more severe than that of wild type mouse although initial changes are similar in both species of mice. These results suggest that susceptibility of hsp70.1(-/-) KO mouse to UVB irradiation may originate from a defect in the repair mechanism. This HSP deficient model may be useful in studies of the effects of tissue injury that relate to the impaired tissue repair mechanisms.
Kwon
Sun Bang
SB
Department of Dermatology and Artificial Organ Laboratory of the Clinical Research Institute, Seoul National University College of Medicine, 110-744, Seoul, South Korea.
Young
Cui
C
Kim
Dong Seok
DS
Choi
Hyun Ok
HO
Kim
Kyu Han
KH
Chung
Jin Ho
JH
Eun
Hee Chul
HC
Park
Kyoung Chan
KC
Oh
Chang Kyu
CK
Seo
Jeong Sun
JS
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D001483:Base Sequence; D004247:DNA / Q000235:genetics; D018390:Gene Targeting; D018840:HSP70 Heat-Shock Proteins / Q000172:deficiency* / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D008854:Microscopy, Electron; D015800:Protozoan Proteins / Q000235:genetics*; D012867:Skin / Q000293:injuries / Q000378:metabolism* / Q000473:pathology / Q000528:radiation effects*; D013471:Sunburn / Q000209:etiology / Q000473:pathology; D014466:Ultraviolet Rays / Q000009:adverse effects*
D018840:HSP70 Heat-Shock Proteins; D015800:Protozoan Proteins; C081884:heat-shock protein 70.1; D004247:DNA