title: The effect of capacitively coupled (CC) electrical stimulation on human disc nucleus pulposus cells and the relationship between CC and BMP-7.
abstract: An in vitro study using human intervertebral disc nucleus pulposus cells to evaluate the effects of CC stimulation on disc-matrix macromolecule production.
  
  
  
  Nucleus pulposus cells were cultured in alginate beads and treated with CC stimulation. The effect of BMP on CC stimulation of the cells was evaluated by applying a BMP blocker (noggin) or by applying additional BMP-7 to the culture. The mRNA levels of the disc extracellular matrix genes (collagen I, II, aggrecan) and BMPs were measured by real-time PCR. The protein levels of aggrecan, collagen II, and BMPs were determined by ELISAs and Western blots. Sulfated glycosaminoglycan (sGAG) content was assayed using the DMMB method.
  
  
  
  (1) CC stimulation upregulates the production of the disc-matrix macromolecular components: sGAG, aggrecan and collagen II; (2) CC stimulation increases the ratio of mRNA expression levels of collagen II to collagen I; (3) CC stimulation induces the expression of endogenous BMP-4 and BMP-7; (4) inhibition of BMP activity (using noggin) reduces CC-mediated upregulation of aggrecan and collagen II; (5) CC and BMP-7 act in synergy to increase the upregulation of disc-matrix macromolecules.
  
  
  
  CC stimulation upregulates the production of the intervertebral disc-matrix macromolecules aggrecan, collagen II, and sGAG by a mechanism involving BMPs. CC stimulation acts in synergy with BMP-7 to increase the upregulation of these disc-matrix macromolecules.
authors.affiliation: The Atlanta Department of Veterans Affairs Medical Center, The Emory Spine Center, Emory University School of Medicine, Atlanta, GA, USA. zwang2@emory.edu.
authors.forename: Zili
authors.initials: Z
authors.lastname: Wang
authors.affiliation: The Atlanta Department of Veterans Affairs Medical Center, The Emory Spine Center, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Hutton
authors.affiliation: The Atlanta Department of Veterans Affairs Medical Center, The Emory Spine Center, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: S Tim
authors.initials: ST
authors.lastname: Yoon
mesh_terms: D053674:Aggrecans / Q000235:genetics / Q000378:metabolism; D055415:Bone Morphogenetic Protein 4 / Q000235:genetics / Q000378:metabolism; D055419:Bone Morphogenetic Protein 7 / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024043:Collagen Type II / Q000235:genetics / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods*; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D007403:Intervertebral Disc / Q000166:cytology; D000070614:Nucleus Pulposus / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: D053674:Aggrecans; C525809:BMP4 protein, human; C525819:BMP7 protein, human; D055415:Bone Morphogenetic Protein 4; D055419:Bone Morphogenetic Protein 7; D024042:Collagen Type I; D024043:Collagen Type II; D006025:Glycosaminoglycans; D012333:RNA, Messenger
keywords: Aggrecan; BMP-7; Capacitively coupled electrical stimulation; Disc cell biology; Disc degeneration