The pentapeptide KTTKS promoting the expressions of type I collagen and transforming growth factor-β of tendon cells

✍ Scribed by Wen-Chung Tsai; Chih-Chin Hsu; Chia-Ying Chung; Miao-Sui Lin; Sung-Lung Li; Jong-Hwei S. Pang

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 198 KB
• Volume: 25
• Category: Article
• ISSN: 0736-0266
• DOI: 10.1002/jor.20455

✦ Synopsis

Abstract

Pentapeptide KTTKS, a subfragment of type I collagen propeptide, has been demonstrated to promote the extracellular release of collagen in fibroblasts. The present study was designed to investigate the effect and molecular mechanism of KTTKS on type I collagen expression of rat Achilles tendon cells. Genes related to the upregulation of collagen expression such as transforming growth factor‐β (TGF‐β), and mRNA‐binding proteins (mRBP) E1 and K were also examined. MTT assay revealed cell viability was not affected by KTTKS treatment. Protein expression of type I collagen was determined by immunocytochemistry and Western blot analysis. Results showed that KTTKS induced type I collagen expression of tendon cells. The mRNA expressions of α1(I) procollagen, TGF‐β, mRBP K, as determined by reverse transcription‐polymerase chain reaction (RT‐PCR), were also enhanced after KTTKS treatment. The stability of preexisting α1(I) procollagen mRNA after the addition of α‐amanitin was analyzed by RT‐PCR at 24 and 48 h. Results showed that KTTKS slowed down the degradation of α1(I) procollagen mRNA (p = 0.021). Furthermore, the concentration of TGF‐β in conditioned medium, as determined by enzyme‐linked immunosorbent assay, increased dose dependently in cells treated with KTTKS (p = 0.001). In conclusion, KTTKS promotes the expression of type I collagen and maintains its mRNA stability in a process associated with the upregulation of TGF‐β. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1629–1634, 2007