Coexpression of Notch3 and Rgs5 in the pericyte-vascular smooth muscle cell axis in response to pulp injury

Abstract

Recent studies have shown that the pulp of human teeth contains a population of cells with stem cell properties and it has been suggested that these cells originate from pericytes. Molecules of the Notch signaling pathway regulate stem cell fate specification, while Rgs5 represents an excellent marker for pericytes. Pathological conditions such as dental trauma and carious lesion stimulate pulp stem cells to elaborate reparative dentin. Previous studies have shown that genes involved in the Notch pathway are activated in response to pulp injury in rodent and humans. To demonstrate the importance of pericytes as a source of stem cells during dental repair, we have studied Rgs5 and Notch3 mRNA expression by in situ hybridization in developing, adult intact and injured rodent teeth. Furthermore, we have examined the distribution of Notch3 protein in carious and injured human teeth using immunohistochemistry. Overlapping expression patterns of Rgs5 and Notch3 were observed during rodent tooth development as well as immediately after injury. Both genes were expressed in vascular structures during development and in perivascular and single capillary cells of injured teeth. However, the expression patterns of Rgs5 and Notch3 were different during tooth repair, with relatively extensive Rgs5 expression along the pericyte-vascular smooth muscle cell axis in central pulp arterioles. These results show co-expression of Rgs5 and Notch3 in pericytes of developing and injured teeth and furthermore indicate the importance of vascular-derived stem cells during pulp healing.

Tooth Organ Engineering: Biological Constraints Specifying Experimental Approaches

“…Cells with a mesodermal origin participate in the dental pulp formation including the blood vessels, which develop there (Chai et al, 2000;Rothova et al, 2011). Some of the mesenchymal stem cells present in the dental pulp might originate from perycites (Feng et al, 2010;Lovschall et al, 2007). Since the perivascular environment may play an essential role as it remains a potential source of stem cells possibly involved in reparative processes , this context could explain the results published by Arany and coworkers (2009).…”

Fighting for territories: time-lapse analysis of dental pulp and dental follicle stem cells in co-culture reveals specific migratory capabilities

“…Dental pulp stem cells (DPSC) and dental follicle stem cells (DFSC) were sorted by FACS using cell-surface markers such as CD117, CD34 and flk-1 for DPSC (d'Aquino et al, 2007;Graziano et al, 2008;Tirino et al, 2011) and SSEA4, OCT-4, TRA1-80 and TRA1-81 for DFSC . These stem cell populations reside in various niches within the dental pulp and follicle (Lovschall et al, 2007;. DPSC are very flexible and can differentiate into chondrocytes, adipocytes, neurons, muscles, odontoblasts and bone cells.…”

Stem cells for tooth engineering

“…Among these signals are the calcium hydroxide or calcium phosphate materials, which constitute pulp-capping materials used by dentists for common dental treatments. Dental pulp progenitors have not been clearly identified but some data suggest that pericytes, which are able to differentiate into osteoblasts, could also differentiate into odontoblasts (Alliot-Licht et al, 2005;Lovschall et al, 2007;Shi and Gronthos, 2003). Tooth repair is a lifetime process thus suggesting that MSC might exist in adult dental pulp.…”