title: Effect of interleukin-1β treatment on co-cultures of human meniscus cells and bone marrow mesenchymal stromal cells.
abstract: BACKGROUND
  Interleukin-1β (IL-1β) is a major mediator of local inflammation present in injured joints. In this study, we aimed at comparing the effect of IL-1β on engineered tissues from MCs, BMSCs and co-cultured MCs and BMSCs.
  
  
  METHODS
  We compared the effect of IL-1β in 3 groups: (1) MCs, (2) BMSCs and, (3) co-cultures of MCs and BMSCs. We selected 1 to 3 ratio of MCs to BMSCs for the co-cultures. Passage two (P2) human BMSCs were obtained from two donors. Human MCs were isolated from menisci of 4 donors. Mono-cultures of MCs and BMSCs, and co-cultures of MCs and BMSCs were cultured in chondrogenic medium with TGFβ3, as cell pellets for 14 days. Thereafter, pellets were cultured for 3 more days in same medium as before with or without IL-1β (500 pg/ml). Pellets were assessed histologically, biochemically and by RT-PCR for gene expression of aggrecan, sox9, MMP-1, collagens I and II. Statistics was performed using one-way ANOVA with Tukey's post-tests.
  
  
  RESULTS
  Co-cultured pellets were the most intensely stained with safranin O and collagen II. Co-cultured pellets had the highest expression of sox9, collagen I and II. IL-1β treatment slightly reduced the GAG/DNA of co-cultured pellets but still exceeded the sum of the GAG/DNA from the proportion of MCs and BMSCs in the co-cultured pellets. After IL-1β treatment, the expression of sox9, collagen I and II in co-cultured pellets was higher compared to their expression in pure pellets. IL-1β induced MMP-1 expression in mono-cultures of MCs but not significantly in mono-cultures of BMSCs or in co-cultured pellets. IL-1β induced MMP-13 expression in mono-cultured pellets of BMSCs and in co-cultured pellets.
  
  
  CONCLUSIONS
  Co-cultures of MCs and BMSCs resulted in a synergistic production of cartilaginous matrix compared to mono-cultures of MCs and BMSCs. IL-1β did not abrogate the accumulated GAG matrix in co-cultures but mediated a decreased mRNA expression of aggrecan, collagen II and Sox9. These results strengthen the combinatorial use of primary MCs and BMSCs as a cell source for meniscus tissue engineering by demonstrating retention of fibrochondrogenic phenotype after exposure to IL-1β.
authors.affiliation: Department of Surgery, Division of Orthopaedic Surgery, Laboratory of Stem Cell Biology and Orthopaedic Tissue Engineering, University of Alberta, Edmonton, AB T6G 2E1, Canada.
authors.forename: Anika
authors.initials: A
authors.lastname: Chowdhury
authors.forename: Louis W
authors.initials: LW
authors.lastname: Bezuidenhout
authors.forename: Aillette
authors.initials: A
authors.lastname: Mulet-Sierra
authors.forename: Nadr M
authors.initials: NM
authors.lastname: Jomha
authors.forename: Adetola B
authors.initials: AB
authors.lastname: Adesida
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D020219:Chondrogenesis / Q000187:drug effects* / Q000502:physiology; D018920:Coculture Techniques; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism; D006801:Humans; D053583:Interleukin-1beta / Q000494:pharmacology*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000096:biosynthesis; D008592:Menisci, Tibial / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D059630:Mesenchymal Stem Cells / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D023822:Tissue Engineering; D053782:Transforming Growth Factor beta3 / Q000494:pharmacology
chemical_list: D015415:Biomarkers; D006025:Glycosaminoglycans; D053583:Interleukin-1beta; D053782:Transforming Growth Factor beta3; D020781:Matrix Metalloproteinase 1