Project/Area Number |
18390314
|
Research Category |
Grant-in-Aid for Scientific Research (B)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Dermatology
|
Research Institution | Ehime University |
Principal Investigator |
HASHIMOTO Koji Ehime University, Graduate School of Medicine, Professor (00110784)
|
Co-Investigator(Kenkyū-buntansha) |
SHIRAKATA Yuji Ehime University, Graduate School of Medicine, Senior Assistant Professor (50226320)
HANAKAWA Yasushi Ehime University, Graduate School of Medicine, Assistant Professor (90284398)
HIRAKAWA Satoshi Ehime University, University Hospital, Senior Assistant Professor (50419511)
|
Project Period (FY) |
2006 – 2007
|
Project Status |
Completed (Fiscal Year 2007)
|
Budget Amount *help |
¥17,400,000 (Direct Cost: ¥15,600,000、Indirect Cost: ¥1,800,000)
Fiscal Year 2007: ¥7,800,000 (Direct Cost: ¥6,000,000、Indirect Cost: ¥1,800,000)
Fiscal Year 2006: ¥9,600,000 (Direct Cost: ¥9,600,000)
|
Keywords | psoriasis / keratinocytes / SOCS3 / STAT3 / keratinocyte-specific knockout mouse / regeneration / RT-PCR / epidermal thickenin |
Research Abstract |
STAT3 is a latent cytoplasmic protein that conveys signals to the nucleus upon stimulation with IL-6, EGF and many other growth factors. STAT3 plays critical roles in biological function such as cell proliferation, migration and so on. Suppressors of cytokine signaling (SOCS) regulate the strength of cytokine signals. SOCS3 is strongly induced by a variety of cytokines and other stimulators. The suppressive effect of SOCS3 has been shown to be relatively specific to STAT3. Therefore we investigated the role of SOCS3 in epidermal keratinocytes. Since germline targeting of the SOCS3 gene resulted in embryonic lethality, we generated keratinocyte-specific SOCS3-deficient mice (KS-SOCS3-/-mice) using Cre/loxP technology in combination with the keratin 5 promoter. KS-SOCS3-/-mice were viable and their skin appeared normal at birth. No histological alterations were found in skin of KS-SOCS3-/-mice, however, after 20 weeks, their skin was red and scaly, hyperkeratotic lesions developed in the
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ear, tail and the back skin in some mice. Histological analysis of skin lesions showed a marked hyperplasia, elongation of rete ridge, loss of granular layer and parakeratosis. These phenotype and histology show a strong resemblance to human psoriasis lesions. Next we utilized tape stripping which is a mild form of epidermal injury. KS-SOCS3-/-mice developed scaly lesions as early as 4days after stripping, whereas wild type mice showed a mild phenotype. The phenotype found in KS-SOCS3-/-mice prolonged until 14 days after stripping when wild type mice showed no obvious clinical phenotype. Tape stripping-induced lesions of KS-SOCS3-/-mice also showed histological feature of human psoriasis. Keratinocytes in the epidermis of KS-SOCS3-/-mice were highly positive for Ki67. Phosphorylated STAT3 staining was strong in KS-SOCS3-/-mice compared to wild type mice. In conclusion, loss of SOCS3, an endogenous inhibitor of STAT3, in epidermal keratinocytes leads to clinical phenotype of human psoriasis. Less
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