Anterior cruciate ligament-derived cells have high chondrogenic potential

Journal Orthopaedic Research

Hachioji

et al. 2011

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ABSTRACT:The meniscus plays an important role in controlling the biomechanics of the knee. However, the mechanical stress-related response in meniscus cells remains unclear. We investigated mechanical stretch-regulated gene expression in human meniscus cells. Human inner and outer meniscus cells were prepared from the inner and outer halves of the lateral meniscus. The gene expressions of Sry-type HMG box (SOX) 9 and a1(II) collagen (COL2A1) were assessed by real-time PCR analyses after cyclic tensile strain (CTS) treatment (0.5 Hz, 5% stretch). The localization and phosphorylation of SOX9 were evaluated by immunohistochemical and Western blot (WB) analyses. Chromatin immunoprecipitation (IP) analysis was performed to assess the stretch-related protein-DNA complex formation between SOX9 and the COL2A1 enhancer on chromatin. Type II collagen deposition and SOX9 production were detected only in inner menisci. CTS treatments increased expression of the COL2A1 and SOX9 genes in inner meniscus cells, but not in outer meniscus cells. In addition, CTS treatments stimulated nuclear translocalization and phosphorylation of SOX9 in inner meniscus cells. Chromatin IP analyses revealed that CTS increased the association between SOX9 and its DNA-binding site, included in the COL2A1 enhancer, on chromatin. Our results indicate that inner and outer meniscus cells have different properties in mechanical stretchinduced COL2A1 expression. In inner meniscus cells, mechanical stretch may have an essential role in the epigenetic regulation of COL2A1 expression. ß

Section: Cyclic Tensile Strain (Cts)mentioning

confidence: 99%

Mechanical stretch enhances COL2A1 expression on chromatin by inducing SOX9 nuclear translocalization in inner meniscus cells

Kanazawa

Journal Orthopaedic Research

Hachioji

et al. 2011

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“…Quantitative real-time PCR analyses were performed using LightCycler ST-300 and FastStart DNA Master SYBR Green I kit (Roche). Chondrogenic redifferentiation was assessed using the primers for SOX9, SOX5/6, and α1(II) collagen (COL2A1) [16,20]. Amplification of glyceraldehyde-3-phosphate dehydrogenase (G3PDH) was used for normalisation [16].…”

Section: Quantitative Real-time Pcr Analysesmentioning

confidence: 99%

“…In vitro differentiation was performed as described [16]. For chondrogenic redifferentiation, pelleted micromass culture was performed.…”

Section: In Vitro Differentiation and Histological Analysesmentioning

confidence: 99%

Comparison between normal and loose fragment chondrocytes in proliferation and redifferentiation potential

Sakata

International Orthopaedics (SICOT)

Miyazawa

et al. 2012

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Purpose Loose fragments in osteochondritis dissecans (OCD) of the knee require internal fixation. On the other hand, loose fragments derived from spontaneous osteonecrosis of the knee (SONK) are usually removed. However, the difference in healing potential between OCD-and SONK-related loose fragments has not been elucidated. In this study, we investigated proliferative activity and redifferentiation potential of normal cartilage-derived and loose fragment-derived chondrocytes. Methods Cells were prepared from normal articular cartilages and loose fragment cartilages derived from knee OCD and SONK. Cellular proliferation was compared. Redifferentiation ability of pellet-cultured chondrocytes was assessed by real-time PCR analyses. Mesenchymal differentiation potential was investigated by histological analyses. Positive ratio of a stem cell marker CD166 was evaluated in each cartilaginous tissue. Results Normal and OCD chondrocytes showed a higher proliferative activity than SONK chondrocytes. Chondrogenic pellets derived from normal and OCD chondrocytes produced a larger amount of safranin O-stained proteoglycans compared with SONK-derived pellets. Expression of chondrogenic marker genes was inferior in SONK pellets. The CD166-positive ratio was higher in normal cartilages and OCD loose fragments than in SONK loose fragments. Conclusions The OCD chondrocytes maintained higher proliferative activity and redifferentiation potential compared with SONK chondrocytes. Our results suggest that chondrogenic properties of loose fragment-derived cells and the amount of CD166-positive cells may affect the repair process of osteochondral defects.

“…Immunohistochemical analysis: MCL sections were also assessed by immunohistochemical analyses using anti-type I (Merck) and anti-type III (Monosan) collagen antibodies as described [21].…”

Section: Injury Model and Growth Factor Treatmentmentioning

confidence: 99%

Combined use of bFGF and GDF-5 enhances the healing of medial collateral ligament injury

Saiga

Biochemical and Biophysical Research Communications

Yoshida

et al. 2010

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Basic fibroblast growth factor (bFGF) and growth and differentiation factor (GDF)-5 stimulate the healing of medial collateral ligament (MCL) injury. However, the effect of isolated and combined use of bFGF/GDF-5 remains still unclear. We investigated cellular proliferation and migration responding to bFGF/GDF-5 using rabbit MCL fibroblasts. Rabbit MCL injury was treated by bFGF and/or GDF-5 with peptide hydrogels. Gene expression and deposition of collagens in healing tissues were evaluated. bFGF/GDF-5 treatment additively enhanced cell proliferation and migration. bFGF/GDF-5 hydrogels stimulated Col1a1 expression without increasing Col3a1 expression. Combined use of bFGF/GDF-5 stimulated type I collagen deposition and the reorganization of fiber alignment, and induced better morphology of fibroblasts in healing MCLs. Our study indicates that combined use of bFGF/GDF-5 might enhance MCL healing by increasing proliferation and migration of MCL fibroblasts, and by regulating collagen synthesis and connective fiber alignment.