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Updated: Mar 14, 2026

Isolation, Culture, and Characterization of Primary Dermal Fibroblasts from Human Keloid Tissue
Published on: July 28, 2023
miR-21 promotes collagen production in keloid via Smad7
Renpeng Zhou1, Chen Wang1, Congji Wen2
1Department of Plastic and Reconstructive Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi Zao Ju Road, Shanghai 200011, PR China.
Objective:
To explore the biological function of miR-21 in the formation of keloid.
Methods:
Normal skin and keloid tissue samples underwent histopathologic study and qPCR analysis. The expression of miR-21 and mRNA expression of Smad7, Col1A1, Col3A1 in fibroblasts derived from keloid tissue and normal skin tissue samples were detected by qPCR. Normal and keloid fibroblasts were transfected with miR-21 mimics or inhibitor respectively, and expression of Smad7, Col1A1 and Col3A1 were examined. After the normal fibroblasts were transfected with Smad7 siRNA, expression of Col1A1 and Col3A1 were detected by Western blot and qPCR analysis.
Results:
Collagen was obviously thick and disorganized in keloid tissue. The expression of miR-21, Col1A1 and Col3A1 in keloid tissue and keloid-derived fibroblasts were higher than that of normal counterparts, while the expression of Smad7 in keloid tissue and keloid-derived fibroblasts was lower. miR-21 mimics attenuated expression of Smad7, and enhanced the expression of Col1A1, Col3A1. Furthermore, the Smad7 siRNA increased expression of Col1A1and Col3A1.
Conclusions:
miR-21 promoted collagen production in keloid by negatively regulating the expression of the Smad7.
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