Temporomandibular Joint Fibrocartilage Contains CD105 Positive Mouse Mesenchymal Stem/Progenitor Cells with Increased Chondrogenic Potential

Janis R Thamm; Youssef Jounaidi; Max-Laurin Mueller; Vicki Rosen; Maria J Troulis; Fernando Pozzi Semeghini Guastaldi

doi:10.1007/s12663-022-01721-6

Temporomandibular Joint Fibrocartilage Contains CD105 Positive Mouse Mesenchymal Stem/Progenitor Cells with Increased Chondrogenic Potential

J Maxillofac Oral Surg. 2023 Sep;22(3):559-570. doi: 10.1007/s12663-022-01721-6. Epub 2022 May 9.

Authors

Janis R Thamm¹, Youssef Jounaidi², Max-Laurin Mueller¹, Vicki Rosen³, Maria J Troulis^{1

4}, Fernando Pozzi Semeghini Guastaldi^{1

5}

Affiliations

¹ Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Harvard School of Dental Medicine, Boston, MA USA.
² Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA USA.
³ Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA USA.
⁴ Walter C. Guralnick Professor of Oral and Maxillofacial Surgery, Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Harvard School of Dental Medicine, Boston, MA USA.
⁵ Skeletal Biology Research Center, Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Harvard School of Dental Medicine, 50 Blossom St, Thier 513A, Boston, MA 02114 USA.

Abstract

Objective: A specific type of mesenchymal stem/progenitor cells (MSPCs), CD105⁺ is reported to aid in cartilage regeneration through TGF-β/Smad2-signalling. The purpose of this study was to identify and characterize CD105⁺ MSPCs in temporomandibular joint (TMJ) cartilage.

Materials and methods: MSPCs were isolated from mouse TMJ condyle explants and evaluated for their clonogenicity and pluripotential abilities. MSPC were examined for CD105 antigen using immunohistochemistry and flow cytometry.

Results: Immunohistochemistry revealed presence of CD105⁺ MSPCs in the proliferative zone of condyle's cartilage. Only 0.2% of isolated MSPCs exhibited CD105, along with the stem cell surface markers CD44 and Sca-1. In CD105⁺ MSPCs, intracellular immunostaining revealed significantly higher (p < 0.05) protein levels of collagen type 1, 2, proteoglycan 4. Ability for chondrogenic differentiation was found to be significantly higher (p < 0.05) after 4 weeks compared to CD105^- cells, using alcian blue staining. CD105⁺ cells were found to resemble an early MSPC subgroup with significantly higher gene expression of biglycan, proteoglycan 4, collagen type 2, Gli2, Sox5 (p < 0.001) and Sox9 (p < 0.05). In contrast, significantly lower levels of Runx2 (p < 0.05), Osterix, Trps1, Col10a1 (p < 0.01), Ihh (p < 0.001) related to chondrocyte senescence and commitment to osteogenic lineage, were observed compared to CD105^- cells.

Conclusion: The study showed the existence of a CD105⁺ MSPC subgroup within TMJ fibrocartilage that may be activated to aid in fibrocartilage repair.

Keywords: CD105; Cartilage regeneration; Mesenchymal stem/progenitor cells; Temporomandibular joint.