Korean J Dermatol.  2007 Apr;45(4):362-368.

Down-regulation of Type I Collagen Gene Expression in Human Skin Fibroblasts by G1 Cell Cycle Arrest

• Park YD
• Lee KS

Abstract

BACKGROUND: Type I collagen is a major component of extracellular cellular matrix in tissue. It is synthesized by human skin fibroblasts. However, synthesis of type I collagen is markedly-decreased in senescent fibroblasts. In the cell cycle, the hallmark of senescent fibroblasts is a permanent G1 phase arrest. However it is largely unknown whether the expression of type I collagen protein is decreased by the G1 phase arrest in human skin fibroblasts after UVB irradiation, serum starvation, or mimosine, an inducer of the G1 phase arrest treatment.
OBJECTIVE
The purpose of this study was to investigate the expression of type I collagen protein in G1 phase- arrested human skin fibroblasts after UVB irradiation, serum starvation, and mimosine treatment.
METHODS
To induce G1 phase arrest in the cell cycle, human skin fibroblasts were irradiated by UVB (100, 200, 300 mJ/cm(2)), subjected to serum starvation for 5 days, or mimosine treatment (50, 100, 200 uM). The expressions of type I collagen protein were analyzed by Western blot analysis.
RESULTS
The G1 phase of cell populations were increased by a dose or time-dependent manner with UVB irradiation, serum starvation, and mimosine-treated human skin fibroblasts. The expression of type I collagen protein was markedly-decreased by UVB, serum starvation, and mimosine treatment.
CONCLUSION
The expression of type I collagen protein in human skin fibroblasts is decreased by UVB irradiation, serum starvation, and mimosine treatment through induction of G1 phase cell cycle arrest.

Keyword

Fibroblast; G1 phase arrest; Type I collagen

MeSH Terms

Blotting, Western
Cell Cycle
Cell Cycle Checkpoints
Collagen Type I*
Down-Regulation*
Fibroblasts*
G1 Phase
G1 Phase Cell Cycle Checkpoints*
Gene Expression*
Humans*
Mimosine
Skin*
Starvation
Collagen Type I
Mimosine