Mutation of the Collagen Type 1α Gene in Human Fibrosarcoma Cells Using the CRISPR/Cas9 System

Collagen in the connective tissue plays a key role in the expression the aging phenotypes. While collagen production decreases with aging, collagenase expression increases, resulting in collagen breakdown. The purpose of this study is to investigate the change in the expression of proteins and genes related to the collagen signaling pathway, cell cycle, and aging phenotypes of cells with the collagen type 1 α (COL1A1) gene edited by the CRISPR/Cas9 system. The mutation of the COL1A1 gene was induced by the CRISPR/Cas9 system. Sanger DNA sequencing and Indel analyses, Sanger DNA sequencing analysis and Swiss protein modeling analysis were used to verify the induction of mutation. Aging phenotypes in the mutated cells were evaluated by collagen staining assay, SA-β-galactosidase staining assay, RT-PCR assay, Western blot analysis, gelatin zymography, and immunofluorescent staining assay. Sanger DNA sequencing analysis demonstrated that human fibrosarcoma cells with COL1A1 gene mutations were successfully established in this study. Swiss protein modeling analysis displayed the altered structure of COL1A1 in the edited cells. In addition, while collagen production was decreased, the SA-β-galactosidase staining level was increased in the edited cells. It was also found that the expression levels of CDC2, CDk2, and cyclin D were increased by down-regulating p53 and p21 levels through the increased expression of MDM2 in the edited cells. Moreover, the expression levels of MMP-1, MMP-2, MMP-9, AKT, and p-mTOR were reduced in the edited cells. These findings could provide a crucial clue in elucidating the close relationship between collagen production and senescence.