Dataset Information

Expansion of the sagittal suture induces proliferation of skeletal stem cells and sustains endogenous calvarial bone regeneration

ABSTRACT: In newborn humans, and up to approximately 2 y of age, calvarial bone defects can naturally regenerate. This remarkable regeneration potential is also found in newborn mice and is absent in adult mice. Since previous studies showed that the mouse calvarial sutures are reservoirs of calvarial skeletal stem cells (cSSCs), which are the cells responsible for calvarial bone regeneration, here we hypothesized that the regenerative potential of the newborn mouse calvaria is due to a significant amount of cSSCs present in the newborn expanding sutures. Thus, we tested whether such regenerative potential can be reverse engineered in adult mice by artificially inducing an increase of the cSSCs resident within the adult calvarial sutures.First, we analyzed the cellular composition of the calvarial sutures in newborn and in older mice, up to 14-mo-old mice, showing that the sutures of the younger mice are enriched in cSSCs. Then, we demonstrated that a controlled mechanical expansion of the functionally closed sagittal sutures of adult mice induces a significant increase of the cSSCs. Finally, we showed that if a calvarial critical size bone defect is created simultaneously to the mechanical expansion of the sagittal suture, it fully regenerates without the need for additional therapeutic aids. Using a genetic blockade system, we further demonstrate that this endogenous regeneration is mediated by the canonical Wnt signaling.This study shows that controlled mechanical forces can harness the cSSCs and induce calvarial bone regeneration. Similar harnessing strategies may be used to develop novel and more effective bone regeneration autotherapies.

ORGANISM(S): Mus musculus

PROVIDER: GSE227468 | GEO | 2023/04/11

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Children less than 2 years of age are capable of healing large calvarial defects, whereas adults have been found to lack this endogenous ability. In this study, we used microarray analysis to compare genomewide expression patterns during active regeneration after injury with calvaria in skeletally immature and mature mice. Parietal bone defects were created in 6-day-old (juvenile) and 60-day-old (adult) mice using a 4-mm trephine bit (n = 20 mice per age group). The calvarial disc was removed, leaving the underlying dura mater intact. Two weeks after injury, the region of regeneration with the underlying dura mater was harvested, and RNA was extracted for microarray analysis. The 25 most differentially upregulated genes in juvenile regenerates compared with adults were listed, as well as selected bone-related genes. In addition, QRT-PCR confirmation of specific genes was performed for validation. Juvenile regenerates expressed significantly greater amounts of BMP-2, -4, -7, as well as FGF-2 and its receptor FGFR-1. Various other growth factors were also noted to be upregulated, including IGF-2 and Ptn. This corresponded with the increased expression of markers for osteogenic differentiation of Sparc and Oc. Markers of osteoclast activity, Acp5, Ctsk, and Mmp2, were noted to be greater in juvenile regenerates compared with adults. The observation of Mmp14 upregulation, however, highlights the importance of balanced osteoclast-mediated bone resorption for ultimate healing. The 2 most differentially regulated genes, transthyretin (Ttr) and prostaglandin D2 synthase (Ptgds), highlight the potential role of retinoic acid signaling and the prostaglandin axis on skeletal regeneration. These findings underscore the multitude of biomolecular mechanisms at play, allowing juvenile calvaria to heal after injury. The identification of various growth factors and cytokines involved also suggests novel therapeutic strategies for tissue-engineering purposes. Set of arrays that are part of repeated experiments Elapsed Time: Calvarial regeneration in 6 day old vs 60 day old mice Biological Replicate

Dataset Information

Expansion of the sagittal suture induces proliferation of skeletal stem cells and sustains endogenous calvarial bone regeneration

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure