Cue-Signal-Response Analysis in 3D Chondrocyte Scaffolds with Anabolic Stimuli

Ann Biomed Eng. 2018 Feb;46(2):345-353. doi: 10.1007/s10439-017-1964-8. Epub 2017 Nov 16.


Articular cartilage is an avascular connective tissue responsible for bearing loads. Cell signaling plays a central role in cartilage homeostasis and tissue engineering by directing chondrocytes to synthesize/degrade the extracellular matrix or promote inflammatory responses. The aim of this paper was to investigate anabolic, catabolic and inflammatory pathways of well-known and underreported anabolic stimuli in 3D chondrocyte cultures and connect them to diverse cartilage responses including matrix regeneration and cell communication. A cue-signal-response experiment was performed in chondrocytes embedded in alginate scaffolds subjected to a 9-day treatment with 7 anabolic cues. At the signaling level diverse pathways were measured whereas at the response level glycosaminoglycan (GAG) synthesis and cytokine releases were monitored. A significant increase of GAG was observed for each stimulus and well known anabolic phosphoproteins were activated. In addition, WNK1, an underreported protein of chondrocyte signaling, was uncovered. At the extracellular level, inflammatory and regulating cytokines were measured and DEFB1 and CXCL10 were identified as novel contributors to chondrocyte responses, both closely linked to TLR signaling and inflammation. Finally, two new pro-growth factors with an inflammatory potential, Cadherin-11 and MGP were observed. Interestingly, well-known anabolic stimuli yielded inflammatory responses which pinpoints to the pleiotropic roles of individual stimuli.

Keywords: Cartilage scaffolds; Cell signaling; Osteoarthritis; Proteomics; Tissue engineering.

MeSH terms

  • Aged
  • Alginates / chemistry*
  • Cell Culture Techniques
  • Cells, Cultured
  • Chemokine CXCL10 / metabolism
  • Chondrocytes / metabolism*
  • Chondrocytes / pathology
  • Cytokines / metabolism
  • Female
  • Glycosaminoglycans / biosynthesis
  • Humans
  • Inflammation / metabolism
  • Inflammation / pathology
  • Male
  • Signal Transduction*
  • Tissue Scaffolds / chemistry*
  • Toll-Like Receptors / metabolism
  • WNK Lysine-Deficient Protein Kinase 1 / metabolism
  • beta-Defensins / metabolism


  • Alginates
  • CXCL10 protein, human
  • Chemokine CXCL10
  • Cytokines
  • DEFB1 protein, human
  • Glycosaminoglycans
  • Toll-Like Receptors
  • beta-Defensins
  • WNK Lysine-Deficient Protein Kinase 1
  • WNK1 protein, human