Role of nitric oxide signaling components in differentiation of embryonic stem cells into myocardial cells

Abstract

cardiomyogenesis ͉ cyclic GMP ͉ soluble guanylyl cyclase ͉ NO donors ͉ sGC activators E mbryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo, and because of their selfrenewal and pluripotency, they are thought to revolutionize the field of regenerative medicine (1-3). Although transplantation of stem cells into animal models of cardiac injury and Parkinson's disease has revealed some beneficial effects, a better understanding of the role of specific signaling pathways involved in proliferation and differentiation of ES cells is necessary to improve their use in clinical medicine (4-6). Components of a number of signaling pathways such as Wnt/␤-catenin (7), phosphotidyle-inosital 3-kinase (8, 9), MAPK (10), and NO (11) have been shown to regulate proliferation and differentiation of stem cells.NO is a diffusible short-lived free radical and a signaling molecule with a number of important physiological functions such as smooth muscle relaxation, neurotransmission, and inhibition of platelet aggregation and host defense mechanisms (12). It also plays a role in the pathology of several inflammatory diseases and other pathological conditions such as cancer, diabetes, and neurodegenerative diseases (13,14). NO plays an important role in the control of heart rate, contractibility, coronary perfusion, and cardiac development (15, 16). It is synthesized by enzymes called nitric oxide synthases such as NOS-1 (neuronal NOS), NOS-2 (inducible NOS), and NOS-3 (endothelial NOS) that catalyze the oxidation of L-arginine into L-citruline with the release of NO. NO can also be measured in biological systems as metabolites of NO and as nitrites and nitrates (17). The NO receptor soluble guanylyl cyclase (sGC) is a heme-containing heterodimer with ␣ and ␤ subunits (12). Binding of NO to the heme prosthetic group of sGC catalyzes the conversion of GTP into the second messenger cGMP that can exert many physiological effects, such as mediating vascular smooth muscle tone and motility, phototransduction, and maintenance of fluid and electrolyte homeostasis by interaction of cGMP with downstream effectors such as a family of cGMP-dependent protein kinases, cGMP-dependent phosphodiesterases, and cyclic nucleotide gated channels (11).Our previous studies with mouse and human ES cells demonstrated a time-dependent increase in mRNA and protein levels of different subunits of sGC (with the exception of ␤2 mRNA in H-9 cells) during both mouse and human ES cell differentiation into cells of cardiac lineage. Compared with NOS-1, NOS-2, and NOS-3 mRNA and protein levels were also induced during ES cell differentiation (18,19), thereby demonstrating the involvement of NO signaling components during differentiation of ES cells into cardiac cells. Previous studies by other investigators (20) have shown increased cardiomyogenesis with NO donors and by delivery of the NOS-2 gene in mouse ES cells.In this study, we demonstrate the role of NO and cGMP in differentiation of human and mouse ES cells by regulating t...

Role of Nitric Oxide Signaling in Endothelial Differentiation of Embryonic Stem Cells

“…In a recent study of human and mouse ESCs, NO donors and sGC activators could increase the mRNA expression of cardiacspecifi c genes myosin light chain and Nkx2.5, whereas NOS inhibitors decreased their mRNA expression [ 9 ].…”

“…In this way, NO regulates diverse cellular processes in the cardiovascular, central nervous system, and immune system of the adult mammal. Several reports also suggest a role for NO signaling in cardiac differentiation [9][10][11][12]. Furthermore, defects in bicuspid aortic valves and atrial and ventricular septa are common in endothelial NOS (eNOS)-defi cient neonates [ 13 , 14 ].…”

Curcumin induces differentiation of embryonic stem cells through possible modulation of nitric oxide-cyclic GMP pathway

“…Our previous studies using ES cells indicate differential expression and function of various NO signaling components Mujoo et al, 2006) in ES and differentiated cells. Using activators of NO signaling pathway, we were able to show enhanced differentiation of both mouse and human ES cells with combination of nitric oxide donors (NO donors) and soluble guanylyl cyclase (NO receptor) activators compared to either of the two agents used separately (Mujoo et al, 2008). Nitric oxide mediates important physiological functions associated with integrative body systems including cardiovascular and nervous system, (Murad, 2006;Mujoo et al, 2011).…”

“…Furthermore, we have shown that both nitric oxide donors and soluble guanylyl cyclase (NO receptor) activators demonstrate enhanced differentiation of human and mouse embryonic stem cells and combined effects of these agents were additive. This was accompanied by robust induction in cGMP production compared with either of the two agents alone suggesting that NO-cGMP pathway plays a significant role in differentiation of stem cells (Mujoo et al, 2008).…”

“…Previous studies have shown that p53 induces differentiation of stem cells by inhibiting the gene expression of nanog, a stem cell marker (Yang, 2005;Lin et al, 2005). We recently demonstrated that cGMP is important for the processes involved in differentiation of human embryonic stem cells (Mujoo et al, 2008). The role of cAMP in differentiation of stem cells towards various lineages has been established many years ago (Goldstein et al, 1990).…”