Developmental Origin of a Bipotential Myocardial and Smooth Muscle Cell Precursor in the Mammalian Heart

Abstract

Despite recent advances in delineating the mechanisms involved in cardiogenesis, cellular lineage specification remains incompletely understood. To explore the relationship between developmental fate and potential, we isolated a cardiac-specific Nkx2.5(+) cell population from the developing mouse embryo. The majority of these cells differentiated into cardiomyocytes and conduction system cells. Some, surprisingly, adopted a smooth muscle fate. To address the clonal origin of these lineages, we isolated Nkx2.5(+) cells from in vitro differentiated murine embryonic stem cells and found approximately 28% of these cells expressed c-kit. These c-kit(+) cells possessed the capacity for long-term in vitro expansion and differentiation into both cardiomyocytes and smooth muscle cells from a single cell. We confirmed these findings by isolating c-kit(+)Nkx2.5(+) cells from mouse embryos and demonstrated their capacity for bipotential differentiation in vivo. Taken together, these results support the existence of a common precursor for cardiovascular lineages in the mammalian heart.

Eomesodermin induces Mesp1 expression and cardiac differentiation from embryonic stem cells in the absence of Activin

“…Eomes overexpression also promoted the appearance of endothelial cells (expressing VE-cadherin and CD31; Fig 1D,E,J) and smooth muscle cells (expressing smooth muscle actin; Fig 1F,G,K and supplementary Fig S2B online). Altogether, the three types of cells derived from multipotent cardiovascular progenitors (MCPs) [27,[35][36][37] were massively increased following Eomes expression in DDM, although we cannot rule out that some endothelial and smooth muscle cells could also derive from other progenitors (such as the hemangioblasts [38] that could also be induced following Eomes expression). We and others have recently demonstrated that a combination of monoclonal antibodies (Flk1/Pdgfra) can be used to isolate the earliest Mesp1 expressing MCPs arising during ESC differentiation [16,27].…”

Defining the earliest step of cardiovascular progenitor specification during embryonic stem cell differentiation

“…Using the same markers as to isolate the different MCPs during embryonic de velopment, mouse and human bipotent and tripotent MCPs have been isolated during ESC differentiation, giving rise to CMs, SMCs, and ECs similar to their in vivo potential (Kattman et al, 2006;Moretti et al, 2006;Wu et al, 2006;Yang et al, 2008;Bu et al, 2009). The spontaneous appearance of cardiovascular cells during the differentiation of ESCs has created great enthu siasm among developmental biologists for studying, using reductionist in vitro approaches, the complex cellular and mo lecular mechanisms governing cardiovascular differentiation and cardiovascular diseases as well as providing a means of generating cardiovascular cells for cellular therapy and drug or toxicity screening (Murry and Keller, 2008).…”

“…Random labeling of cardiac precursors during em bryonic development also revealed the existence of rare clones that contributed to both FHF and SHF lineages and that could repre sent a common cardiovascular progenitor for both heart fields (Meilhac et al, 2004). Recent studies showed that, during mouse embryonic development, tripotent MCPs that are able to differen tiate at the clonal level into CMs, SMCs, and ECs can be marked and isolated based on Brachyury (Bry) and Flk1 (Kattman et al, 2006) or Isl1 and Flk1 expression (Moretti et al, 2006), whereas bipotent MCPs that give rise to CM and SMC lineages can be iso lated based on Nkx2-5 and c Kit expression (Wu et al, 2006). These studies demonstrated that cardiac cells arise from the differ entiation of multipotent progenitors, with the ability to differenti ate at the clonal level into the different cardiovascular lineages (Kattman et al, 2006;Moretti et al, 2006;Wu et al, 2006).…”

“…Recent studies showed that, during mouse embryonic development, tripotent MCPs that are able to differen tiate at the clonal level into CMs, SMCs, and ECs can be marked and isolated based on Brachyury (Bry) and Flk1 (Kattman et al, 2006) or Isl1 and Flk1 expression (Moretti et al, 2006), whereas bipotent MCPs that give rise to CM and SMC lineages can be iso lated based on Nkx2-5 and c Kit expression (Wu et al, 2006). These studies demonstrated that cardiac cells arise from the differ entiation of multipotent progenitors, with the ability to differenti ate at the clonal level into the different cardiovascular lineages (Kattman et al, 2006;Moretti et al, 2006;Wu et al, 2006). D uring embryonic development and embryonic stem cell (ESC) differentiation, the different cell lineages of the mature heart arise from two types of multipotent cardiovascular progenitors (MCPs), the first and second heart fields.…”

P2X1 receptor-mediated inhibition of the proliferation of human coronary smooth muscle cells involving the transcription factor NR4A1

“…However, culturing of vascular smooth muscle cells has been reported to possibly cause a loss in the expression of P2X 1 receptors [30,31]. Moreover, coronary smooth muscle cells and myocardial cells are likely to be derived from a common precursor cell [32], suggesting potential differences of coronary smooth muscle on the one hand and noncoronary vascular smooth muscle on the other hand. Therefore, we now examined the effects of α,β-methylene-ATP and its analog β,γ-methylene-ATP on the proliferation of human coronary smooth muscle cells cultured under conditions suitable to maintain the contractile smooth muscle phenotype [20,25].…”