Neural regulation of mesenchymal stem cells in craniofacial bone: development, homeostasis and repair

Abstract

Mesenchymal stem cells endow various functions, including proliferation, multipotency, migration, etc. Craniofacial bones originate from the cranial neural crest and are developed mainly through intramembranous ossification, which are different from long bones. There are varied mesenchymal stem cells existing in the craniofacial bone, including Gli1 + cells, Axin2 + cells, Prx1 + cells, etc. Nerves distributed in craniofacial area are also derived from the neural crest, and the trigeminal nerve is the major sensory nerve in craniofacial area. The nerves and the skeleton are tightly linked spatially, and the skeleton is broadly innervated by sensory and sympathetic nerves, which also participate in bone development, homeostasis and healing process. In this review, we summarize mesenchymal stem cells located in craniofacial bone or, to be more specific, in jaws, temporomandibular joint and cranial sutures. Then we discuss the research advance concerning neural regulation of mesenchymal stem cells in craniofacial bone, mainly focused on development, homeostasis and repair. Discovery of neural regulation of mesenchymal stem cells may assist in treatment in the craniofacial bone diseases or injuries.

Keywords: craniofacial bone; development; homeostasis; mesenchymal stem cell; nerve; repair.

FIGURE 1

Schematics of craniofacial MSCs, residing in jaws, TMJ and cranial sutures. 1) In the alveolar bone, LepR+, Gli1+, and SM22α + MSCs have been discovered. 2) Gli1 + MSCs also reside in apical mesenchyme. 3) Prx1 + MSCs exist in the mandible. 4) Krt14 + Ctsk + MSCs are in the maxillary sinus and nasal cavity. 5) Gli1 + MSCs are in the TMJ subchondral bone, the periosteum and the perichondrium of TMJ condyle. 6) α-SMA + MSCs reside in the fibrous superficial zone tissue in the TMJ condyle. 7) Thy1 + MSCs are in the TMJ disc. 8) Gli1+, Bmpr1a+, Axin2+, Prx1+, Ctsk + and Ddr2 + MSCs have been found in the cranial sutures (Created with BioRender.com).