Is cultured tendon fibroblast a good model to study tendon healing?
Cultured tendon fibroblasts (CTFs) from intact explants are widely used to study tendon healing in vitro. The significance of these findings may rely on similarities between CTFs and healing tendon fibroblasts in situ. Our purpose was to compare CTFs with fibroblasts cultured from healing tendons. We cultured CTFs from intact and healing tendons at day 7 and day 14 postinjury in a rat model of patellar donor site injury. The mRNA expression of COL1A1, COL3A1, decorin, and biglycan, with or without supplementation of 1 ng/mL TGF-beta1, was compared by quantitative real-time RT-PCR. The expression of proliferation cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SMA) was determined by immunostain. COL3A1 and decorin mRNA in CTFs was lower as compared to day 7 healing fibroblasts, but its biglycan mRNA level was higher than day 14 healing fibroblasts. TGF-beta1 increased COL1A1 and decorin mRNA in CTFs, but decreased the mRNA of all four genes in day 7 healing tendon fibroblasts. CTFs exhibited lower PCNA immunopositivity as compared to day 7 and day 14 healing fibroblasts, but a higher alpha-SMA immunopositivity than cultured day 14 healing fibroblasts. These findings showed that CTFs did not resemble healing tendon cells with respect to major cellular activities related to tendon healing. Thus, fibroblasts from healing tendon may be a more appropriate model for studying cellular activities in tendon healing.
Fu
Sai-Chuen
SC
Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong.
Cheuk
Yau-Chuk
YC
Chan
Kai-Ming
KM
Hung
Leung-Kim
LK
Wong
Margaret Wan-Nar
MW
D000199:Actins / Q000235:genetics; D000818:Animals; D002478:Cells, Cultured; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012107:Research Design / Q000592:standards; D013708:Tendon Injuries / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D013997:Time Factors; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology; D014945:Wound Healing
D000199:Actins; D016326:Extracellular Matrix Proteins; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1