Induced 2C Expression and Implantation-Competent Blastocyst-like Cysts from Primed Pluripotent Stem Cells.

Soon after fertilization, the few totipotent cells of mammalian embryos diverge to form a structure called the blastocyst (BC). Although numerous cell types, including germ cells and extended-pluripotency stem cells, have been developed from pluripotent stem cells (PSCs) in vitro, generating functional BCs only from PSCs remains elusive. Here, we describe induced self-organizing 3D BC-like cysts (iBLCs) generated from mouse PSC culture. Resembling natural BCs, iBLCs have a blastocoel-like cavity and were formed with outer cells expressing trophectoderm lineage markers and with inner cells expressing pluripotency markers. iBLCs transplanted to pseudopregnant mice uteruses implanted, induced decidualization, and exhibited growth and development before resorption, demonstrating that iBLCs are implantation competent. iBLC precursor intermediates required the transcription factor Prdm14 and concomitantly activated the totipotency-related cleavage-stage MERVL reporter and 2C genes. Thus, our system may contribute to the understanding of molecular mechanisms underpinning totipotency, embryogenesis, and implantation.

Cardiac Adipose-Derived Stem Cells Exhibit High Differentiation Potential to Cardiovascular Cells in C57BL/6 Mice.

Adipose-derived stem cells (AdSCs) have recently been shown to differentiate into cardiovascular lineage cells. However, little is known about the fat tissue origin-dependent differences in AdSC function and differentiation potential. AdSC-rich cells were isolated from subcutaneous, visceral, cardiac (CA), and subscapular adipose tissue from mice and their characteristics analyzed. After four different AdSC types were cultured with specific differentiation medium, immunocytochemical analysis was performed for the assessment of differentiation into cardiovascular cells. We then examined the in vitro differentiation capacity and therapeutic potential of AdSCs in ischemic myocardium using a mouse myocardial infarction model. The cell density and proliferation activity of CA-derived AdSCs were significantly increased compared with the other adipose tissue-derived AdSCs. Immunocytochemistry showed that CA-derived AdSCs had the highest appearance rates of markers for endothelial cells, vascular smooth muscle cells, and cardiomyocytes among the AdSCs. Systemic transfusion of CA-derived AdSCs exhibited the highest cardiac functional recovery after myocardial infarction and the high frequency of the recruitment to ischemic myocardium. Moreover, long-term follow-up of the recruited CA-derived AdSCs frequently expressed cardiovascular cell markers compared with the other adipose tissue-derived AdSCs. Cardiac adipose tissue could be an ideal source for isolation of therapeutically effective AdSCs for cardiac regeneration in ischemic heart diseases. Significance: The present study found that cardiac adipose-derived stem cells have a high potential to differentiate into cardiovascular lineage cells (i.e., cardiomyocytes, endothelial cells, and vascular smooth muscle cells) compared with stem cells derived from other adipose tissue such as subcutaneous, visceral, and subscapular adipose tissue. Notably, only a small number of supracardiac adipose-derived stem cells that were systemically transplanted sufficiently improved cardiac functional recovery after myocardial infarction, differentiating into cardiovascular cells in the ischemic myocardium. These findings suggest a new autologous stem cell therapy for patients with myocardial ischemia, especially those with secondary myocardial ischemia after cardiovascular open chest surgery.

Switching to aggressive statin improves vascular endothelial function in patients with stable coronary artery disease.

AIM: The clinical relevance of the suggested pleiotropic effects of hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) is controversial. Aggressive statins effectively reduce lipid levels, but whether their other effects are more powerful than those of regular statins is unknown. METHODS: We enrolled 32 patients (mean age, 65 y; male, 23) who had undergone coronary revascularization over 6 months previously and whose serum LDL cholesterol levels persisted at >100 mg/dL, regardless of pravastatin (10 mg/day). Before and 1 and 6 months after switching to atorvastatin (10 mg/day), we evaluated lipid profiles, including RLP-C (remnant-like particle cholesterol), high sensitive CRP (hsCRP), soluble CD40 ligand (sCD40L), TBARS (thiobarbituric acid reactive substances), and endothelial function determined from flow-mediated dilation (FMD) of the brachial artery. RESULTS: One month on atorvastatin lowered LDL cholesterol by 24% (131 to 100 mg/dL, p<0.001). In addition, RLP-C, sCD40L and hsCRP significantly decreased, whereas FMD did not change. After 6 months of this therapy, FMD significantly improved compared to baseline values (5.1 vs 3.6%, p=0.04). Changes in FMD and in total and RLP cholesterol significantly correlated. Moreover, FMD was remarkably improved in patients who achieved target LDL levels (<100 mg/dL). CONCLUSIONS: Switching from a regular to an aggressive statin can improve endothelial function at 6 months in patients with previous coronary artery disease. This effect is suggested to be mainly due to the lipid-lowering effect. Achievement and maintenance of the target LDL level by switching statins is beneficial in the clinical setting.

Adrenal androgen dehydroepiandrosterone sulfate inhibits vascular remodeling following arterial injury.

Recent epidemiologic studies have suggested that serum dehydroepiandrosterone sulfate (DHEAS) levels have a significant inverse correlation with the incidence of cardiovascular diseases. However, direct evidence for the association with DHEAS and vascular disorders has not yet been explored. DHEAS significantly reduced neointima formation 28 days after surgery without altering other serum metabolite levels in a rabbit carotid balloon injury model. Immunohistochemical analyses revealed the reduction of proliferating cell nuclear antigen (PCNA) index and increase of TdT-mediated dUTP-biotin Nick End Labeling (TUNEL) index, expressing differentiated vascular smooth muscle cell (VSMC) markers in the media 7 days after surgery. In vitro, DHEAS exhibited inhibitory effects on VSMC proliferation and migration activities, inducing G1 cell cycle arrest with upregulation of one of the cyclin dependent kinase (CDK) inhibitors p16(INK4a) and apoptosis with activating peroxisome proliferator-activated receptor (PPAR)-alpha in VSMCs. DHEAS inhibits vascular remodeling reducing neointima formation after vascular injury via its effects on VSMC phenotypic modulation, functions and apoptosis upregulating p16(INK4a)/activating PPARalpha. DHEAS may play a pathophysiological role for vascular remodeling in cardiovascular disease.

Different migratory and proliferative properties of smooth muscle cells of coronary and femoral artery.

In the human coronary arteries, the intima begins to thicken from early adolescence and shows progressive thickening with age. We compared the response to vascular injury of the coronary and femoral arteries using a canine model. Both incorporation of 5-bromo-2'-deoxyuridine (BrdU) and neointimal formation after balloon injury were significantly greater in the coronary artery than in the femoral artery. Also, the proliferative and migratory activities of coronary smooth muscle cells (SMCs) were significantly greater than those of femoral SMCs in vitro. The level of phosphorylated myosin light chain (phospho-MLC) was higher in coronary SMCs than in femoral SMCs. Y-27632, a specific inhibitor of Rho-kinase, significantly inhibited the PDGF-induced migration of both coronary and femoral SMCs. In contrast, the migration of coronary SMCs, but not femoral SMCs, was inhibited by ML-9, a specific inhibitor of myosin light chain kinase (MLCK). These findings suggest that the contribution of Rho-kinase and MLCK differs between the different arteries. They also suggest that a neointima develops more easily in the coronary artery than in the femoral artery because of the greater proliferative and migratory activity of coronary SMCs. Differential activation of MLC might partly explain the increased proliferation and migration of coronary SMCs.