Neurotrophin‐3 acts on the endothelial‐mesenchymal transition of heterotopic ossification in rats

Abstract

Despite the fact that extensive studies have focused on heterotopic ossification (HO), its molecular mechanism remains unclear. The endothelial‐mesenchymal transition (EndMT), which may be partially modulated by neuroendocrine cytokines is thought to play a major role in HO. Neurotrophin‐3 (NT‐3), which has neuroendocrine characteristics is believed to promote skeletal remodeling. Herein, we suggest that that NT‐3 may promote HO formation through regulation of EndMT. Here, we used an in vivo model of HO and an in vitro model of EndMT induction to elucidate the effect and underlying mechanism of NT‐3 on EndMT in HO. Our results showed that heterotopic bone and cartilage arose from EndMT and NT‐3 promoted HO formation in vivo. Our in vitro results showed that NT‐3 up‐regulated mesenchymal markers (FSP‐1, α‐SMA and N‐cadherin) and mesenchymal stem cell (MSC) markers (STRO‐1, CD44 and CD90) and down‐regulated endothelial markers (Tie‐1, VE‐cadherin and CD31). Moreover, NT‐3 enhanced a chondrogenesis marker (Sox9) and osteogenesis markers (OCN and Runx2) via activation of EndMT. However, both EndMT specific inhibitor and tropomyosin‐related kinase C (TrkC) specific inhibitor rescued NT‐3‐induced HO formation and EndMT induction in vivo and in vitro. In conclusion, our findings demonstrate that NT‐3 promotes HO formation via modulation of EndMT both in vivo and in vitro, which offers a new potential target for the prevention and therapy of HO.

Severe Heterotopic Ossification in the Skeletal Muscle and Endothelial Cells Recruitment to Chondrogenesis Are Enhanced by Monocyte/Macrophage Depletion

“…EndoMT has been previously proposed to contribute to early phases of HO (51, 54, 59) and inhibition of EndoMT could rescue HO in vivo and in vitro (59). It has been suggested that the “transition” to a mesenchymal state in EndoMT and in Epithelial to mesenchymal transition (EMT), could indeed favor the acquisition of “stem-like” properties.…”

Neuromodulation of bone: Role of different peptides and their interactions (Review)

“…NT-3 has been shown to promote osteogenesis by increasing BMP2-mediated Smad activation in BMSCs, while it inhibits collagen II expression and suppress chondrogenesis (132). However, NT-3 accelerates chondrogenesis of mesenchymal stem-like cells acquired from the endothelial progenitor cells underwent endothelial-mesenchymal transition, which serves an important role during heterotopic ossification (135). Similar to BDNF, NT-3 also promotes VEGF secretion of BMSCs and endothelial cells, partially through the PI3K/Akt signaling pathway; the enhanced vascularization effect accelerates diabetic wound healing and promotes bony repair at the injured growth plate (132,136).…”

Melatonin Promotes Heterotopic Ossification Through Regulation of Endothelial-Mesenchymal Transition in Injured Achilles Tendons in Rats

“…Previous studies have reported that tendon-derived stem cells (TDSCs) ( Jiang et al, 2017 ), hematopoietic stem cells and myofibroblasts are considered candidates for potential osteogenic cell types ( Zhang et al, 2016 ). In a recent study, vascular endothelial cells that undergo the endothelial-mesenchymal transition (EndMT) process were found to play a role in HO formation in injured Achilles tendons in rats ( Zhang et al, 2019 ). EndMT begins when endothelial cells delaminate from the organized cell layer and invade the underlying tissue, causing the loss of endothelial-specific markers, including vascular endothelial cadherin (VE-cadherin), cluster of differentiation 31 (CD31), tyrosine kinase with immunoglobulin-like and EGF-like 1 (Tie-1), and the gain of mesenchymal-specific markers, such as vimentin, neural cadherin (N-cadherin) and fibroblast-specific protein 1 (FSP-1).…”

“…Many reports have suggested that under pathological conditions, vascular endothelial cells that undergo EndMT are able to acquire the differentiation potential of mesenchymal stem-like cells, and these endothelial-derived MSC-like cells contribute to HO formation by differentiating into chondrocytes and osteoblasts ( Medici et al, 2010 ; Medici and Olsen, 2012 ; Zhang et al, 2016 ). Recently, in a rat model of Achilles tendon injury, we observed the conversion of vascular endothelial cells into MSC-like cells through BMP-4- or TGF-β2-induced EndMT ( Zhang et al, 2019 ). Furthermore, these newly formed cells represented the dedifferentiation of endothelial cells into a stem cell phenotype, and cells of this phenotype can subsequently redifferentiate into osteoblasts and chondrocytes and contribute to HO formation.…”

“…Current studies hold the view that the effect of neuroendocrine signals in regulating the abnormal differentiation of MSCs at injured sites is one of the vital factors that affects the pathogenesis of HO formation ( Gugala et al, 2018 ; Huang et al, 2018 ). A recent study demonstrated that Neurotrophin-3, with its neuroendocrine characteristics, can modulate the EndMT process in HO formation in rats ( Zhang et al, 2019 ), suggesting that neuroendocrine cytokines can participate in the regulation of EndMT. Melatonin ( N -acetyl-5-methoxytryptamine) is a neuroendocrine hormone that is secreted mainly by the pineal gland in mammals and is also expressed in other tissues, such as the ovary, testis, gut, and placenta ( Fan et al, 2020 ).…”