H‐type blood vessels participate in alveolar bone remodeling during murine tooth extraction healing

Abstract

Objectives We aimed to investigate whether skeletal‐specific H‐type blood vessels exist in alveolar bone and how they function in alveolar bone remodeling. Materials and Methods H‐type vessels with high expression of CD31 and Endomucin (CD31hiEmcnhi) were immunostained in alveolar bone. Abundance and age‐related changes in CD31hiEmcnhi endothelial cells (H‐ECs) were detected by flow cytometry. Osteoprogenitors association with H‐type vessels and bone mass were detected in tooth extraction model of alveolar bone remodeling by immunohistofluorescence and micro‐CT, respectively. Transcription and expression of H‐EC feature genes during in vitro Notch inhibition were measured by RT‐qPCR and immunocytofluorescence. Results We verified that H‐type vessels existed in alveolar bone, the abundance of which was highest at infancy age, then decreased but maintained a constant level during aging. In tooth extraction model, H‐ECs significantly increased with concomitant perivascular accumulation of Runx2+ osteoprogenitors and gradually augmentation of bone mass. Notch inhibition of in vitro cultured H‐ECs resulted in decreased expression levels of Emcn and hes1, but not Pecam1 or Kdr genes, with decreased expression levels of H‐EC numbers, accordingly. Conclusions The present study suggests that H‐type vessels promote osteogenesis during alveolar bone remodeling. Notch signaling pathway regulates expression of Emcn and possibly determines fate and functions of alveolar H‐ECs.

Pathological differences in the bone healing processes between tooth extraction socket and femoral fracture

“…This situation might be favored to induce intramembranous bone formation. In addition, intimate coupling of type H endothelium and osteoprogenitors was reported to be essential for bone metabolism and bone healing ( Kusumbe et al, 2014 ; Xu et al, 2018 ), and this coupling has also been observed in tooth extraction models in mice ( Yan et al, 2020 ). Further investigation to compare type H endothelium distribution and function among different bone healing models is of interest to understand the role of type H endothelium in bone regeneration.…”

Different angiogenic response and bone regeneration following the use of various types of collagen membranes - in vivo histomorphometric study in rabbit calvarial critical-size defects

“…In recent years growing body of evidence suggests that blood vessels in bone promote osteogenesis [10,11]. However, there are scarce data regarding the influence of barrier membranes on angiogenesis [12], pointing out the need for its research.…”

A Review Into the Insights of the Role of Endothelial Progenitor Cells on Bone Biology

“…Meanwhile, type H vessels were confirmed in the alveolar bone and tooth extraction socket. ECs of subtype H and Runx2+ osteoprogenitor cells were detected and accumulated at the restoration stage, indicating the potential benefits of ECs of subtype H in bone regeneration ( Yan et al, 2020 ). Additionally, increased formation of type H vessels, consistent with enhanced bone healing, was observed during the treatment of fractures, whether by supplementation with recombinant SLIT3 or by low-intensity pulsed ultrasound ( Xu et al, 2016 ; Xu et al, 2018 ).…”