Rapid differentiation of MSC into adipocytes and osteocytes is facilitated by Toll-Like receptor engagement

2010-04-01
Tas, Ibrahim
Tokcaer-Keskin, Zeynep
Ayhan, Fatma
Gürsel, Mayda
Akcali, Kamil
Mesenchymal stem cells are multipotent progenitor cells capable of differentiating into several lineages including adipocytes, and osteocytes. While they are regarded as non-immunogenic, accumulating evidence suggests that MSC expresses several TLRs. We checked the contribution of TLR ligands to MSC differentiation. Rat bone marrow derived MSC surface marker and TLR transcript levels were checked by FACS and RT-PCR respectively. MSCs were CD29hi, CD71dim, CD90hi, and negative for CD45 & CD34. They expressed TLR1,2,3,4,6, and low levels of 7 and 9 (no TLR5 was detected) at passage zero. Cells were incubated in adipogenic and osteogenic differentiation media either alone or supplemented with, TLR2L:PGN, TLR3L:pI:C, TLR7L:R848, and TLR9L:CpGODN as well as control ODN and followed for three weeks. Oil Red O staining (to assess adipogenesis) suggested that, induction in adipogenic media (by one week) gave no adipose positive cells whereas treatment with R848 or PGN induced significantly high adipose positive cells (1-2% vs 30-35%, respectively). The degree of adipogenic differentiation at wk1, was; TLR7≥TLR2>TLR3>TLR9>Control group≥medium. During osteogenesis (checked by alizarin red staining) by one week the highest differentiation was seen with CpG ODN treatment (TLR9≥TLR7>TLR2>TLR3>Control≥medium). These results strongly support the view that TLR ligands differentially contribute to transition of MSCs into either adipogenic or osteogenic differentiation.
JOURNAL OF IMMUNOLOGY

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Citation Formats
I. Tas, Z. Tokcaer-Keskin, F. Ayhan, M. Gürsel, and K. Akcali, “Rapid differentiation of MSC into adipocytes and osteocytes is facilitated by Toll-Like receptor engagement,” JOURNAL OF IMMUNOLOGY, pp. 0–0, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52720.