Regulatory mechanism of miR-29 over TGF-β1 and COL1 in scar cells

S. Bi, C. Cao, L.-L. Chai, S.-R. Li, D.-Y. Yang

The Third Military Medical University Southwest Plastic Surgery Hospital, Shapingba District, Chongqing, China. lishirong1111@sina.com

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• Pharmacology

OBJECTIVE: To study the regulatory mechanism of miR-29 over TGF-β1 and COL1 in scar cells.

PATIENTS AND METHODS: 5 clinical cases of hypertrophic scar (HS) skin and adjacent normal skin tissues were separated into fibroblast for primary culture and subculture before being observed morphologically and standard HE staining under an ordinary optical microscope. RT-PCR method was applied to test the expression level of miR-29, TGF-β1, and COL1 mRNA. ELISA method was applied to test the expression level of extracellular matrix COL1, fibronectin (FN) and α-SMA. The miR-29 overexpression vector was built and transfected in vitro. RT-PCR method was applied to test related genes and ELISA method was applied to test the expression level of the extracellular matrix.

RESULTS: The color of karyon and cytoplasm of normal fibroblast were both light red, with little ECM. The color of karyon of scar fibroblast was blue. The cytoplasm was red of different degrees, with relatively much ECM, in deep blue color. Compared with that in the normal fibroblast group, the miR-29 mRNA in fibroblast in the scar group significantly decreased (p<0.05). The TGF-β1 and COL1 mRNA significantly increased (p<0.05). The COL1, FN and α-SMA level were significantly higher (p<0.05) than that in the normal group. These mRNAs levels in miR-29 overexpression group were lower than scar group but higher than the normal group.

CONCLUSIONS: The expression of miR-29 which regulates the expression of TGF-β1 and COL1 and increases the level of ECM significantly decreases in scar cells. This one suggests a mechanism of the formation of the scars through TGF-β1 and COL1.

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