Abstract
BackgroundInterleukin-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.MethodsWe 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.ResultsCo-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.ConclusionsCo-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.
Highlights
Interleukin-1β (IL-1β) is a major mediator of local inflammation present in injured joints
Enhanced cartilaginous tissue formation in co-cultures of meniscus cells (MCs) and Bone marrow mesenchymal stromal cells (BMSCs) Firstly, we established that chondrogenic co-culture of Meniscus cells (MCs) and BMSCs resulted in a synergistically enhanced cartilaginous matrix formation relative to mono-cultures of MCs and BMSCs as previously reported [21]
The GAG and collagen II staining intensity was least in monocultured meniscus cell pellets and highest in co-cultured cell pellets of MCs and BMSCs
Summary
Interleukin-1β (IL-1β) is a major mediator of local inflammation present in injured joints. Recent findings in our laboratory and others demonstrated that co-culture of primary human meniscus cells with BMSCs in the presence of chondrogenic factors resulted in a synergistically enhanced production of meniscus-like ECM and fibrocartilage tissue-like formation, but the suppression of hypertrophic differentiation of BMSCs [21,33,34]. We aimed at studying the effect of IL1β on engineered tissues from meniscus cells (MC), BMSCs and co-cultured MCs and BMSCs. We compared the effect of IL-1β in three study groups: (1) MCs, (2) BMSCs and, (3) co-cultures of MCs and BMSCs. For the co-cultured cell group, we selected a 1 to 3 ratio of MCs to BMSCs. Our previous work showed that this ratio reproducibly resulted in synergistic matrix formation after in vitro chondrogenic differentiation in 3D culture using the pellet model of mesenchymal cell condensation [21]. We hypothesized that co-cultured MCs and BMSCs will retain an enhanced chondrogenic matrix-forming capacity compared to mono-cultured MCs and mono-cultured BMSCs after short-term treatment with IL-1β
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
