Expansion and Characterization of Neonatal Cardiac Pericytes Provides a Novel Cellular Option for Tissue Engineering in Congenital Heart Disease

Abstract

BackgroundLiving grafts produced by combining autologous heart-resident stem/progenitor cells and tissue engineering could provide a new therapeutic option for definitive correction of congenital heart disease. The aim of the study was to investigate the antigenic profile, expansion/differentiation capacity, paracrine activity, and pro-angiogenic potential of cardiac pericytes and to assess their engrafting capacity in clinically certified prosthetic grafts.Methods and ResultsCD34pos cells, negative for the endothelial markers CD31 and CD146, were identified by immunohistochemistry in cardiac leftovers from infants and children undergoing palliative repair of congenital cardiac defects. Following isolation by immunomagnetic bead-sorting and culture on plastic in EGM-2 medium supplemented with growth factors and serum, CD34pos/CD31neg cells gave rise to a clonogenic, highly proliferative (>20 million at P5), spindle-shape cell population. The following populations were shown to expresses pericyte/mesenchymal and stemness markers. After exposure to differentiation media, the expanded cardiac pericytes acquired markers of vascular smooth muscle cells, but failed to differentiate into endothelial cells or cardiomyocytes. However, in Matrigel, cardiac pericytes form networks and enhance the network capacity of endothelial cells. Moreover, they produce collagen-1 and release chemo-attractants that stimulate the migration of c-Kitpos cardiac stem cells. Cardiac pericytes were then seeded onto clinically approved xenograft scaffolds and cultured in a bioreactor. After 3 weeks, fluorescent microscopy showed that cardiac pericytes had penetrated into and colonized the graft.ConclusionsThese findings open new avenues for cellular functionalization of prosthetic grafts to be applied in reconstructive surgery of congenital heart disease.

Concise Review: The Regenerative Journey of Pericytes Toward Clinical Translation

“…In addition, microvascular pericytes within the human myocardium exhibit angiogenic behavior in response to hypoxia and seemly have a discernible, though modest, cardiomyogenic potential in vivo . However, data from our group indicate a more restricted fate of pericytes from the human heart and vasculature, with specific commitment to the vascular smooth muscle cell (VSMC) lineage .…”

“…Commonly, these include neural/glial antigen 2 (NG2) proteoglycan, platelet‐derived growth factor receptor‐β (PDGFRβ), and CD146 (Table ), together with mesenchymal markers, such as CD90 and CD105, but absence of CD56, a surface antigen expressed in neurons, glia and skeletal muscle, and hematopoietic and endothelial markers, such as CD45 and CD31, respectively. It is worth keeping in mind, however, that due to the heterogeneity of these cells and lack of an agreed phenotype, different research groups have reported the presence of pericytes within the same tissue but with conflicting antigenic profiles .…”

Myocardial Telocyte-Like Cells: A Review Including New Evidence

“…The CD34+/CD31-/CD146-cardiac non-ECs were found to give rise to a clonogenic, highly proliferative, spindle-shaped, and thus TC-like cell population [Avolio et al, 2015]. The resulting populations were shown to express pericyte/mesenchymal and stemness markers.…”

“…The resulting populations were shown to express pericyte/mesenchymal and stemness markers. Following adequate exposure to differentiation media, the expanded cardiac pericytes acquired the markers of vascular smooth muscle cells, although they failed to differentiate into ECs or cardiomyocytes [Avolio et al, 2015].…”

“…Nevertheless, it was determined that in vitro cardiac pericytes form networks and enhance the network capacity of ECs [Avolio et al, 2015].…”