Tissue Inhibitor of Metalloproteinase-2 Suppresses Collagen Synthesis in Cultured Keloid Fibroblasts.
BACKGROUND
Keloids are defined as a kind of dermal fibroproliferative disorder resulting from the accumulation of collagen. In the remodeling of extracellular matrix, the balance between matrix metalloproteinases (MMPs) and the tissue inhibitors of metalloproteinases (TIMPs) is as critical as the proper production of extracellular matrix. We investigate the role of TIMPs and MMPs in the pathogenesis of keloids and examine the therapeutic potential of TIMP-2.


METHODS
The expression of TIMPs and MMPs in most inflamed parts of cultured keloid fibroblasts (KFs) and peripheral normal skin fibroblasts (PNFs) in the same individuals and the reactivity of KFs to cyclic mechanical stretch were analyzed by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay (n = 7). To evaluate the effect of treating KFs with TIMP-2, collagen synthesis was investigated by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, and microscopic analysis was used to examine the treatment effects of TIMP-2 on ex vivo cultures of keloid tissue (n = 6).


RESULTS
TIMP-2 was downregulated in cultured KFs compared with PNFs in the same individuals, and the reduction in TIMP-2 was exacerbated by cyclic mechanical stretch. Administration of TIMP-2 (200 or 300 ng/mL) significantly suppressed expression of Col1A2 and Col3A1 mRNA and collagen type I protein in KFs. TIMP-2 also significantly reduced the skin dermal and collagen bundle thickness in ex vivo cultures of keloid tissue.


CONCLUSIONS
These results indicated that downregulation of TIMP-2 in KFs is a crucial event in the pathogenesis of keloids, and the TIMP-2 would be a promising candidate for the treatment of keloids.
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Teruyuki
T
Dohi
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Koichi
K
Miyake
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Masayo
M
Aoki
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Rei
R
Ogawa
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Satoshi
S
Akaishi
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Takashi
T
Shimada
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Takashi
T
Okada
Department of Plastic, Reconstructive and Aesthetic Surgery, Nippon Medical School, Tokyo, Japan; and Department of Biochemistry and Molecular Biology, Division of Gene Therapy, Center for Advanced Medical Technology, Nippon Medical School, Tokyo, Japan.
Hiko
H
Hyakusoku