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We previously reported a novel compound called S-nitroso-N-pivaloyl-d-penicillamine (SNPiP), which was screened from a group of nitric oxide donor compounds with a basic chemical structure of S-nitroso-N-acetylpenicillamine, to activate the nonneuronal acetylcholine system. SNPiP-treated mice exhibited improved cardiac output and enhanced diastolic function, without an increase in heart rate. The nonneuronal acetylcholine–activating effects included increased resilience to ischemia, modulation of energy metabolism preference, and activation of angiogenesis. Here, we performed transcriptome analysis of SNPiP-treated mice ventricles to elucidate how SNPiP exerts beneficial effects on cardiac function. A time–course study (24 and 48 hours after SNPiP administration) revealed that SNPiP initially induced Wnt and cyclic guanosine monophosphate–protein kinase G signaling pathways, along with upregulation of genes involved in cardiac muscle tissue development and oxytocin signaling pathway. We also observed enrichment of glycolysis-related genes in response to SNPiP treatment, resulting in a metabolic shift from oxidative phosphorylation to glycolysis, which was suggested by reduced cardiac glucose contents while maintaining adenosine tri-phosphate levels. In addition, SNPiP significantly upregulated atrial natriuretic peptide and sarcolipin, which play crucial roles in calcium handling and cardiac performance. These findings suggest that SNPiP may have therapeutic potential based on the pleiotropic mechanisms elucidated in this study.

Although the physiological meaning of the high potential of mouse embryonic stem cells (ESCs) for meiotic entry is not understood, a rigid safeguarding system is required to prevent ectopic onset of meiosis. PRC1.6, a non‐canonical PRC1, is known for its suppression of precocious and ectopic meiotic onset in germ cells and ESCs, respectively. MGA, a scaffolding component of PRC1.6, bears two distinct DNA‐binding domains termed bHLHZ and T‐box. However, it is unclear how this feature contributes to the functions of PRC1.6. Here, we demonstrated that both domains repress distinct sets of genes in murine ESCs, but substantial numbers of meiosis‐related genes are included in both gene sets. In addition, our data demonstrated that bHLHZ is crucially involved in repressing the expression of Meiosin, which plays essential roles in meiotic entry with Stra8, revealing at least part of the molecular mechanisms that link negative and positive regulation of meiotic onset. MGA bearing two distinct DNA‐binding domains is a scaffolding component of PRC1.6 that prevents precocious and ectopic onset of meiosis in germ cells and embryonic stem cells (ESCs), respectively. Here, we demonstrate that both Mga domains repress distinct sets of meiosis‐related genes in ESCs. Our data also identified Meiosinas a linchpin molecule between positive and negative regulations of meiotic onset.

Embryonic stem cells (ESCs) exhibit two salient features beneficial for regenerative medicine: unlimited self‐renewal and pluripotency. Methyl‐CpG‐binding domain protein 3 (Mbd3), a scaffolding component of the nucleosome remodeling deacetylase complex, is a specific regulator of pluripotency, as ESCs lacking Mbd3 are defective for lineage commitment potential but retain normal self‐renewal properties. However, functional similarities and dissimilarities among the three Mbd3 isoforms (a, b, and c) have not been intensively explored. Herein, we demonstrated that Mbd3c, which lacks an entire portion of the MBD domain, exerted equivalent activity for counteracting the defective lineage commitment potential of Mbd3‐knockout ESCs. Our analyses also revealed that the coiled‐coil domain common to all three MBD3 isoforms, but not the MBD domain, plays a crucial role in this activity. Mechanistically, our data demonstrate that the activity of the coiled‐coil domain is exerted, at least in part, through recruitment of polycomb repressive complex 2 to a subset of genes linked to development and organogenesis, thus establishing stable transcriptional repression. StemCells2018;36:1355–1367 Methyl‐CpG‐binding domain protein 3 (Mbd3), a scaffolding component of nucleosome remodeling and deacetylation complex, is dispensable for self‐renewal, but essential for their differentiation potential of embryonic stem cells (ESCs). Mbd3 bears two prominent domains, that is, MBD and coiled‐coil domain. Our analyses revealed that coiled‐coil domain, but not MBD, is crucially involved in preserving differentiation potential of ESCs. Our analyses revealed that the coiled‐coil domain is involved in the recruitment of polycomb repressive complex 2 for establishing stable repression of genes related to development.

Identification of a gene set capable of driving rapid and proper reprogramming to induced pluripotent stem cells (iPSCs) is an important issue. Here we show that the efficiency and kinetics of iPSC reprogramming are dramatically improved by the combined expression of Jarid2and genes encoding its associated proteins. We demonstrate that forced expression of JARID2 promotes iPSC reprogramming by suppressing the expression of Arf, a known reprogramming barrier, and that the N‐terminal half of JARID2 is sufficient for such promotion. Moreover, JARID2 accelerated silencing of the retroviral Klf4transgene and demethylation of the Nanogpromoter, underpinning the potentiating activity of JARID2 in iPSC reprogramming. We further show that JARID2 physically interacts with ESRRB, SALL4A, and PRDM14, and that these JARID2‐associated proteins synergistically and robustly facilitate iPSC reprogramming in a JARID2‐dependent manner. Our findings provide an insight into the important roles of JARID2 during reprogramming and suggest that the JARID2‐associated protein network contributes to overcoming reprogramming barriers. StemCells2016;34:322–333

Nucleostemin (NS) is a nucleolar GTP‐binding protein that is involved in a plethora of functions including ribosomal biogenesis and maintenance of telomere integrity. In addition to its expression in cancerous cells, the NSgene is expressed in stem cells including embryonic stem cells (ESCs). Previous knockdown and knockout studies have demonstrated that NS is important to preserve the self‐renewality and high expression levels of pluripotency marker genes in ESCs. Here, we found that forced expression of Nanog or Esrrb, but not other pluripotency factors, resulted in the dispensability of NSexpression in ESCs. However, the detrimental phenotypes of ESCs associated with ablation of NSexpression were not mitigated by forced expression of Rad51 or a nucleolar localization‐defective NS mutant that counteracts the damage associated with loss of NSexpression in other NS‐expressing cells such as neural stem/progenitor cells. Thus, our results indicate that NSparticipates in preservation of the viability and integrity of ESCs, which is distinct from that in other NS‐expressing cells. StemCells2015;33:1089–1101

c‐Myc and phosphatidylinositol 3‐OH kinase (PI3K) both participate in diverse cellular processes, including cell cycle control and tumorigenic transformation. They also contribute to preserving embryonic stem cell (ESC) characteristics. However, in spite of the vast knowledge, the molecular relationship between c‐Myc and PI3K in ESCs is not known. Herein, we demonstrate that c‐Myc and PI3K function cooperatively but independently to support ESC self‐renewal when murine ESCs are cultured under conventional culture condition. Interestingly, culture of ESCs in 2i‐condition including a GSK3β and MEK inhibitor renders both PI3K and Myc signaling dispensable for the maintenance of pluripotent properties. These results suggest that the requirement for an oncogenic proliferation‐dependent mechanism sustained by Myc and PI3K is context dependent and that the 2i‐condition liberates ESCs from the dependence of this mechanism. StemCells2015;33:713–725

c‐Myc participates in diverse cellular processes including cell cycle control, tumorigenic transformation, and reprogramming of somatic cells to induced pluripotent cells. c‐Myc is also an important regulator of self‐renewal and pluripotency of embryonic stem cells (ESCs). We recently demonstrated that loss of the Maxgene, encoding the best characterized partner for all Myc family proteins, causes loss of the pluripotent state and extensive cell death in ESCs strictly in this order. However, the mechanisms and molecules that are responsible for these phenotypes remain largely obscure. Here, we show that Sirt1, p53, and p38MAPKare crucially involved in the detrimental phenotype of Max‐null ESCs. Moreover, our analyses revealed that these proteins are involved at varying levels to one another in the hierarchy of the pathway leading to cell death in Max‐null ESCs. STEMCELLS2012;30:1634–1644