Differentiation Potential of Mesenchymal Stem Cells Derived from Adipose Tissue vs Bone Marrow Toward Annulus Fibrosus Cells In vitro

Background: Bone marrow stem cells (BMSCs) and adipose-derived stem cells (ADSCs) are two types of stem cells that commonly used in exogenous tissue engineering as well as endogenous tissue repair, however which type of cell is superior remains unknown. Objective: This study was conducted to compare differentiation potential of BMSCs and ADSCs from Sprague-Dawley rats towards annulus fibrosus (AF)-like cells. Method: Stem cells and AF cells were cocultured with direct cell-to-cell contact in coculture plates with 0.4μm pore size up till 21 days. AF markers expression at the histological level and molecular level were evaluated by histological analysis and dimethplmethplene blue (DMMB) assay as well as quantitative reverse-transcription polymerase chain reaction (qRT-PCR). Results: qRT-PCR) results showed up regulation in AF marker gene expressions of both two MSCs after coculture. BMSCs demonstrated a statistically increased expression of collagen II and aggrecan from 7 days of coculture. However, these gene expressions in ADSCs showed a statistically increase at day 14 and day 21. And there was a statistically increase of Collagen I expression in BMSCs at 14 days and 21 days. But only after 21 days of coculture, ADSCs showed a statistically increase in collagen I expression. Moreover, histological analysis and dimethplmethplene blue (DMMB) assay mirrored the results of qRT-PCR. Morphologically, BMSCs became enlarged and triangular, while ADSCs were enlarged and rounded after coculture. Conclusion: These findings suggested that BMSCs might be superior as a cell source for annulus fibrosus repair compared to ADSCs.