Hitoshi Arimura1, Chisa Shukunami2, Takuya Tokunaga1, Tatsuki Karasugi1, Nobukazu Okamoto1, Takuya Taniwaki1, Hidetoshi Sakamoto3, Hiroshi Mizuta1, Yuji Hiraki4. 1. Department of Orthopaedic Surgery, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan. 2. Department of Mechanical System Engineering, Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan. 3. Department of Mechanical System Engineering, Doshisha University, Kyoto, Japan. 4. Department of Cellular Differentiation, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.
Abstract
BACKGROUND: Transforming growth factor β1 (TGF-β1) positively regulates the tenogenic marker genes scleraxis ( Scx) and tenomodulin ( Tnmd) in mesenchymal progenitors in vitro. However, little is known about the effect of TGF-β1 on the expression of tenogenic markers during rotator cuff (RC) healing in rats. HYPOTHESIS: TGF-β1 improves the biomechanical properties and histological maturity of reparative tissue in a rat RC repair model by stimulating the growth of tenogenic cells. STUDY DESIGN: Controlled laboratory study. METHODS: Adult male Sprague-Dawley rats (N = 180) underwent unilateral supraspinatus tendon-to-bone surgical repair and were randomly treated with a gelatin hydrogel presoaked in TGF-β1 (100 ng) or phosphate-buffered saline. The effects of TGF-β1 on RC healing were investigated at 2, 4, 6, 8, and 12 weeks postoperatively by immunostaining for proliferating cell nuclear antigen, by real-time reverse transcription polymerase chain reaction and in situ hybridization or immunostaining for enthesis-related markers (SRY-box containing gene 9 [ Sox9], Scx, and Tnmd), and by real-time reverse transcription polymerase chain reaction and immunostaining for type I and III collagen. At 6 and 12 weeks postoperatively, biomechanical testing, micro-computed tomography, and biochemical analysis were also performed. At 2 and 4 weeks postoperatively, mesenchymal stem cell-related markers, phospho-Smad2, and matrix metalloproteinase 9 (MMP-9) and MMP-13 were assessed by immunostaining. RESULTS: The TGF-β1-treated group had significantly higher ultimate load to failure and tissue volume at 6 and 12 weeks postoperatively and a higher collagen content at 12 weeks compared with the saline group. Tendon-related gene expression, histological maturity, cell proliferation, and mesenchymal stem cell-related marker immunoreactivity were not affected by exogenously administrated TGF-β1 at all time points. In the TGF-β1-treated group, the percentage of phospho-Smad2-positive cells within the healing tissue increased, whereas the expression of MMP-9 and MMP-13 significantly decreased at 2 and 4 weeks postoperatively. CONCLUSION: TGF-β1 enhances formation of tough fibrous tissues at the healing site by inhibiting MMP-9 and MMP-13 expression to increase collagen accumulation but without the growth of tenogenic lineage cells. CLINICAL RELEVANCE: These findings suggest that TGF-β1 could be used for enhancing biomechanical strength after RC surgical repair.
BACKGROUND: Transforming growth factor β1 (TGF-β1) positively regulates the tenogenic marker genes scleraxis ( Scx) and tenomodulin ( Tnmd) in mesenchymal progenitors in vitro. However, little is known about the effect of TGF-β1 on the expression of tenogenic markers during rotator cuff (RC) healing in rats. HYPOTHESIS: TGF-β1 improves the biomechanical properties and histological maturity of reparative tissue in a rat RC repair model by stimulating the growth of tenogenic cells. STUDY DESIGN: Controlled laboratory study. METHODS: Adult male Sprague-Dawley rats (N = 180) underwent unilateral supraspinatus tendon-to-bone surgical repair and were randomly treated with a gelatin hydrogel presoaked in TGF-β1 (100 ng) or phosphate-buffered saline. The effects of TGF-β1 on RC healing were investigated at 2, 4, 6, 8, and 12 weeks postoperatively by immunostaining for proliferating cell nuclear antigen, by real-time reverse transcription polymerase chain reaction and in situ hybridization or immunostaining for enthesis-related markers (SRY-box containing gene 9 [ Sox9], Scx, and Tnmd), and by real-time reverse transcription polymerase chain reaction and immunostaining for type I and III collagen. At 6 and 12 weeks postoperatively, biomechanical testing, micro-computed tomography, and biochemical analysis were also performed. At 2 and 4 weeks postoperatively, mesenchymal stem cell-related markers, phospho-Smad2, and matrix metalloproteinase 9 (MMP-9) and MMP-13 were assessed by immunostaining. RESULTS: The TGF-β1-treated group had significantly higher ultimate load to failure and tissue volume at 6 and 12 weeks postoperatively and a higher collagen content at 12 weeks compared with the saline group. Tendon-related gene expression, histological maturity, cell proliferation, and mesenchymal stem cell-related marker immunoreactivity were not affected by exogenously administrated TGF-β1 at all time points. In the TGF-β1-treated group, the percentage of phospho-Smad2-positive cells within the healing tissue increased, whereas the expression of MMP-9 and MMP-13 significantly decreased at 2 and 4 weeks postoperatively. CONCLUSION: TGF-β1 enhances formation of tough fibrous tissues at the healing site by inhibiting MMP-9 and MMP-13 expression to increase collagen accumulation but without the growth of tenogenic lineage cells. CLINICAL RELEVANCE: These findings suggest that TGF-β1 could be used for enhancing biomechanical strength after RC surgical repair.
Authors: Fabian Plachel; Philipp Moroder; Renate Gehwolf; Herbert Tempfer; Andrea Wagner; Alexander Auffarth; Nicholas Matis; Stephan Pauly; Mark Tauber; Andreas Traweger Journal: J Orthop Res Date: 2019-06-25 Impact factor: 3.494
Authors: Sang Jun Kim; Seung Mi Yeo; Soo Jin Noh; Chul-Won Ha; Byung Chan Lee; Hyo Sun Lee; Sun Jeong Kim Journal: J Orthop Surg Res Date: 2019-12-02 Impact factor: 2.359