title: Impaired repair ability of hsp70.1 KO mouse after UVB irradiation.
abstract: 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.
authors.affiliation: Department of Dermatology and Artificial Organ Laboratory of the Clinical Research Institute, Seoul National University College of Medicine, 110-744, Seoul, South Korea.
authors.forename: Sun Bang
authors.initials: SB
authors.lastname: Kwon
authors.forename: Cui
authors.initials: C
authors.lastname: Young
authors.forename: Dong Seok
authors.initials: DS
authors.lastname: Kim
authors.forename: Hyun Ok
authors.initials: HO
authors.lastname: Choi
authors.forename: Kyu Han
authors.initials: KH
authors.lastname: Kim
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Chung
authors.forename: Hee Chul
authors.initials: HC
authors.lastname: Eun
authors.forename: Kyoung Chan
authors.initials: KC
authors.lastname: Park
authors.forename: Chang Kyu
authors.initials: CK
authors.lastname: Oh
authors.forename: Jeong Sun
authors.initials: JS
authors.lastname: Seo
mesh_terms: 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*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D015800:Protozoan Proteins; C081884:heat-shock protein 70.1; D004247:DNA