STUDY DESIGN: Human intervertebral disc anulus tissue was obtained in a prospective study of immunolocalization of SPARC (secreted protein, acidic and rich in cysteine) (osteonectin). Experimental studies were approved by the authors' Human Subjects Institutional Review Board. Discs were obtained from surgical specimens and from control donors. OBJECTIVES: To determine whether SPARC could be detected in the disc with immunohistochemistry and to determine the incidence of SPARC-positive cells. SUMMARY OF THE BACKGROUND DATA: SPARC is a glycoprotein that has an important role in modulating interactions between cells and matrix. It influences remodeling, collagen fibrillogenesis, metalloproteinase expression, and cytokine expression. Little is known about SPARC in the disc, and one previous study reported the absence of its immunolocalization in fetal and adult disc tissue. METHODS: Eight normal human discs from subjects aged newborn to 10 years, and 11 disc specimens from control donors or surgical patients aged 15to 76 years were examined for immunolocalization of SPARC. Anulus cells were also tested for the presence of SPARC in vitro in monolayer or three-dimensional agarose culture. RESULTS: In discs of subjects aged newborn to 0.19 years, SPARC was present in all cells in the outer anulus, in 76.4% of inner anulus cells, and 76.0% of nucleus cells. Localization was significantly lower in anulus cells of study participants aged 4.7 to 76 years (66.7%, P = 0.04). Anulus cells cultured in agarose or monolayer showed positive localization in all cells. CONCLUSIONS: Findings show decreased presence of SPARC in disc cells of older subjects with disc degeneration and point to the importance of future studies designed to elucidate the unrecognized role of SPARC in disc remodeling, aging, and degeneration.
STUDY DESIGN:Human intervertebral disc anulus tissue was obtained in a prospective study of immunolocalization of SPARC (secreted protein, acidic and rich in cysteine) (osteonectin). Experimental studies were approved by the authors' Human Subjects Institutional Review Board. Discs were obtained from surgical specimens and from control donors. OBJECTIVES: To determine whether SPARC could be detected in the disc with immunohistochemistry and to determine the incidence of SPARC-positive cells. SUMMARY OF THE BACKGROUND DATA: SPARC is a glycoprotein that has an important role in modulating interactions between cells and matrix. It influences remodeling, collagen fibrillogenesis, metalloproteinase expression, and cytokine expression. Little is known about SPARC in the disc, and one previous study reported the absence of its immunolocalization in fetal and adult disc tissue. METHODS: Eight normal human discs from subjects aged newborn to 10 years, and 11 disc specimens from control donors or surgical patients aged 15to 76 years were examined for immunolocalization of SPARC. Anulus cells were also tested for the presence of SPARC in vitro in monolayer or three-dimensional agarose culture. RESULTS: In discs of subjects aged newborn to 0.19 years, SPARC was present in all cells in the outer anulus, in 76.4% of inner anulus cells, and 76.0% of nucleus cells. Localization was significantly lower in anulus cells of study participants aged 4.7 to 76 years (66.7%, P = 0.04). Anulus cells cultured in agarose or monolayer showed positive localization in all cells. CONCLUSIONS: Findings show decreased presence of SPARC in disc cells of older subjects with disc degeneration and point to the importance of future studies designed to elucidate the unrecognized role of SPARC in disc remodeling, aging, and degeneration.
Authors: Changgui Shi; Sujun Qiu; Scott M Riester; Vaskar Das; Bingqian Zhu; Atiyayein A Wallace; Andre J van Wijnen; Fackson Mwale; James C Iatridis; Daisuke Sakai; Gina Votta-Velis; Wen Yuan; Hee-Jeong Im Journal: J Orthop Res Date: 2018-03-14 Impact factor: 3.494
Authors: Zheng Li; Xingye Li; Chong Chen; Shugang Li; Jianxiong Shen; Gary Tse; Matthew T V Chan; William K K Wu Journal: Cell Prolif Date: 2018-07-24 Impact factor: 6.831
Authors: Maral Tajerian; Sebastian Alvarado; Magali Millecamps; Thomas Dashwood; Kathleen M Anderson; Lisbet Haglund; Jean Ouellet; Moshe Szyf; Laura S Stone Journal: Mol Pain Date: 2011-08-25 Impact factor: 3.395