VEGFR1 primes a unique cohort of dental pulp stem cells for vasculogenic differentiation

Abstract

Dental pulp stem cells (DPSCs) constitute a unique group of cells endowed with multipotency, self-renewal, and capacity to regenerate the dental pulp tissue. While much has been learned about these cells in recent years, it is still unclear if each DPSC is multipotent or if unique sub-populations of DPSCs are “primed” to undergo specific differentiation paths. The purpose of the present study was to define whether a sub-population of DPSCs was uniquely primed to undergo vasculogenic differentiation. Permanent-tooth DPSCs or stem cells from human exfoliated deciduous teeth (SHED) were flow-sorted for vascular endothelial growth factor receptor 1 (VEGFR1) and exposed to vasculogenic differentiation medium, i.e., Microvascular-Endothelial-Cell-Growth-Medium-2-BulletKit™ supplemented with 50 ng/mL rhVEGF165 in the presence of 0 or 25 μg/mL anti-human VEGF antibody (bevacizumab; Genentech). In addition, sorted SHED (i.e., VEGFR1high or VEGFR1low) were seeded in biodegradable scaffolds and transplanted into the subcutaneous space of immunodeficient mice. Despite proliferating at a similar rate, VEGFR1high generated more in vitro sprouts than VEGFR1low cells (p < 0.05). Blockade of VEGF signaling with bevacizumab inhibited VEGFR1high-derived sprouts, demonstrating specificity of responses. Similarly, VEGFR1high SHED generated more blood vessels when transplanted into murine hosts than VEGFR1low cells (p < 0.05). Collectively, these data demonstrated that DPSCs contain a unique sub-population of cells defined by high VEGFR1 expression that are primed to differentiate into vascular endothelial cells. These data raise the possibility of purifying stem cells with high vasculogenic potential for regeneration of vascularized tissues or for vascular engineering in the treatment of ischemic conditions.

Pulpbow: A Method to Study the Vasculogenic Potential of Mesenchymal Stem Cells from the Dental Pulp

“…The Pulpbow cells that initially responded by intense migration towards the sprouts seen in our results, might be cells primed to vascular differentiation such as the VEGFR1positive population described by Bergamo and colleagues [17]. We hypothesize that once the primed cells undergo vasculogenic differentiation and others might be necessary to continue the blood vessel formation, local clonal proliferation such as seen in our study may respond to the cell demand.…”

“…Dental pulp stem cells are composed of different sub-populations and contain at least one unique subset of stem cells characterized by high VEGFR1 expression that are primed for vasculogenic differentiation. This sub-population of cells corresponds to 10–20% of DPSC cells that can differentiate into endothelial cells [ 17 ]. In addition, p53/p21 functioning through Bmi-1 can prevent the vasculogenic differentiation of DPSC cells.…”

Dental Pulp Stem Cell Heterogeneity: Finding Superior Quality “Needles” in a Dental Pulpal “Haystack” for Regenerative Medicine-Based Applications

“…Furthermore, despite not distinguishing multipotent properties, certain cell surface markers have been attributed to the identification of hDPSC subpopulations with specific mesodermal or ectodermal differentiation lineage capabilities. For instance, STRO-1 + /c-Kit + /CD34 + , CD146 -, and CD271 + hDPSCs have a greater propensity towards neurogenic commitment [83,84,87,88], whilst CD105 + , VEGFR1 high , and PDGFRβ + /c-kit + subpopulations have strong tendencies for angiogenic [89,95] and odontogenic [93] lineage differentiation, respectively. Thus, such limited lineage differentiation tendencies may point towards more refined indications for such subpopulations in future for more specific regenerative applications, such as nerve injury and cardiovascular or tooth repair, thereby utilising these hDPSCs for optimised clinical scenarios for which they appear best suited.…”

“…IGF1 receptor (IGF1R), regarded as a pluripotent marker of embryonic stem cells, was also found to be expressed in hDPSCs, with IGF1R + subpopulations displaying both self-renewal and multipotency potentials, especially towards neurogenic and angiogenic lineages [ 94 ]. Similarly, enriched populations of VEGFR1 high hDPSCs have a strong ability to undergo angiogenic differentiation in vitro , producing increased blood vessel sprouting and neovascularisation than VEGFR1 low subpopulations [ 95 ].…”

Role of Heparan Sulfate in Vasculogenesis of Dental Pulp Stem Cells

“…Dental pulp stem cells (DPSCs), which are classified as mesenchymal stem cells, are highly proliferative and exhibit multipotent differentiation into osteoblasts, chondrocytes, and adipocytes (Aydin and Şahin 2019; Luke et al 2020). Notably, owing to constitutive expression of vascular endothelial growth factor (VEGF) receptor 1, DPSCs more readily differentiate into vascular endothelial lineages compared with other mesenchymal cells derived from bone marrow and adipose tissues (Janebodin et al 2013; Bergamo et al 2021). Recent research demonstrated that canonical Wnt/β-catenin and p53/p21 signaling are required for vasculogenic differentiation of DPSCs (Zhang et al 2016; Zhang et al 2021).…”