Monitoring of canonical BMP and Wnt activities during postnatal stages of mouse first molar root formation

Abstract

Monitoring of canonical BMP and Wnt activities during postnatal stages of mouse first molar root formationObjective: This study aimed to explore the precise temporospatial distributions of bone morphogenetic protein (BMP) and Wnt signaling pathways during postnatal development of mammalian tooth roots after the termination of crown morphogenesis. Methodology: A total of two transgenic mouse lines, BRE-LacZ mice and BAT-gal mice, were undertaken. The mice were sacrificed on every postnatal (PN) day from PN 3d up to PN 21d. Then, the first lower molars were extracted, and the dissected mandibles were stained with 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside (X-gal) and fixed. Serial sections at 10 µm were prepared after decalcification, dehydration, and embedding in paraffin. Results: We observed BMP/Smads and Wnt/β-catenin signaling activities in the dental sac, dental pulp, and apical papilla with a certain degree of variation. The position of activation of the BMP/ Smad signaling pathway was located more coronally in the early stage, which then gradually expanded as root elongation proceeded and was associated with blood vessels in the pulp and developing complex apical tissues in the later stage. However, Wnt/β-catenin signaling was highly concentrated in the mesenchyme below the cusps in the early stage, gradually expanded to regions around the root in the transition/root stage, and then disappeared entirely in the later stage. Conclusions: These results further confirmed the participation of both BMP and Wnt canonical signaling pathways in tooth root development, as well as formed the basis for future studies on how precisely integrated signaling pathways regulate root morphogenesis and regeneration.

Mutations in LRP5 and BMP4 are associated with mesiodens, tooth agenesis, root malformation, and oral exostoses

“…In addition, we also show for the first time that mutations in BMP4 are associated with root maldevelopment. Sharing of phenotypes of the patients with LRP5 and BMP4 mutations, which include root maldevelopment, tooth agenesis, and torus mandibularis, implicates cross‐talk between WNT/β‐catenin and BMP signaling pathways, especially during root development 13 …”

980 nm Photobiomodulation Promotes Osteo/Odontogenic Differentiation of the Stem Cells from Human Exfoliated Deciduous Teeth Via the Cross talk Between BMP/Smad and Wnt/β‐Catenin Signaling Pathways

“…Although 980 nm PBM significantly enhanced osteo/odontogenic differentiation, the potential mechanisms remain unclear. BMP and Wnt pathways are the most important pathways in regulating osteo/odontogenic differentiation (21,37,40). Despite this, 980 nm laser irradiation could activate cellular pathways involving the PI3K/serine-threonine kinase (Akt) signaling pathway to increase the production of type-I collagen (Col-I), mineralized matrix and osteocalcin, stimulating preosteoblast differentiation (12).…”

“…The differentiation of odontoblast and the formation of mineralized tissue are regulated by several signaling pathways, such as the Wnt and BMP signaling pathways (21). Upon phosphorylation by BMP receptors activates intracellular downstream Smads and subsequently translocate it to the nucleus, upregulating transcription of key osteo/odontogenic gene makers such as runt‐related transcription factor 2 (RUNX2) and bone sialoprotein (BSP) (22).…”

Progress of Wnt Signaling Pathway in Osteoporosis

“…Both Wnt and BMP signaling pathways participate in tooth development [ 58 ]. They mutually promote or inhibit tooth development by regulating tooth morphology, number, and structure [ 59 ]. Zhang et al found that Wnt/ β -catenin and BMP-9 signaling pathways are involved in the osteogenic differentiation of apical dental papilla stem cells [ 60 ].…”