Background and Aims. Embryonic stem (ES) cells have a pluripotent ability to differentiate into a variety of cell lineages in vitro.We have recently found the emergence of cell clusters that show the cellular uptake of indocyanine green (ICG) in the culture of differentiated ES cells. ICG is clinically used as a test substance to evaluate liver function because it is eliminated exclusively by hepatocytes. The aim of the present study was to investigate the hepatic characteristics of ICG-stained cells.Methods. Embryoid bodies (EBs), formed by a 5-day hanging drop culture of ES cells, were allowed to outgrow in the placed culture. Gene expression of hepatocyte markers was analyzed by reverse transcriptase-polymerase chain reaction, and albumin production was examined immunohistochemically. Morphology and cellular components were investigated by electron microscopy. ICG-stained cells were further transplanted into the portal vein of mice.

Catecholamines and α1-adrenergic receptors (α1-ARs) cause cardiac hypertrophy in cultured myocytes and transgenic mice, but heart size is normal in single KOs of the main α1-AR subtypes, α1A/C and α1B. Here we tested whether α1-ARs are required for developmental cardiac hypertrophy by generating α1A/C and α1B double KO (ABKO) mice, which had no cardiac α1-AR binding. In male ABKO mice, heart growth after weaning was 40% less than in WT, and the smaller heart was due to smaller myocytes. Body and other organ weights were unchanged, indicating a specific effect on the heart. Blood pressure in ABKO mice was the same as in WT, showing that the smaller heart was not due to decreased load. Contractile function was normal by echocardiography in awake mice, but the smaller heart and a slower heart rate reduced cardiac output. α1-AR stimulation did not activate extracellular signal–regulated kinase (Erk) and downstream kinases in ABKO myocytes, and basal Erk activity was lower in the intact ABKO heart. In female ABKO mice, heart size was normal, even after ovariectomy. Male ABKO mice had reduced exercise capacity and increased mortality with pressure overload. Thus, α1-ARs in male mice are required for the physiological hypertrophy of normal postnatal cardiac development and for an adaptive response to cardiac stress

An α 1 -adrenergic receptor (α 1 -AR) antagonist increased heart failure in the Antihypertensive and LipidLowering Treatment to Prevent Heart Attack Trial (ALLHAT), but it is unknown whether this adverse result was due to α 1 -AR inhibition or a nonspecific drug effect. We studied cardiac pressure overload in mice with double KO of the 2 main α 1 -AR subtypes in the heart, α 1A (Adra1a) and α 1B (Adra1b). At 2 weeks after transverse aortic constriction (TAC), KO mouse survival was only 60% of WT, and surviving KO mice had lower ejection fractions and larger end-diastolic volumes than WT mice. Mechanistically, final heart weight and myocyte cross-sectional area were the same after TAC in KO and WT mice. However, KO hearts after TAC had increased interstitial fibrosis, increased apoptosis, and failed induction of the fetal hypertrophic genes. Before TAC, isolated KO myocytes were more susceptible to apoptosis after oxidative and β-AR stimulation, and β-ARs were desensitized. Thus, α 1 -AR deletion worsens dilated cardiomyopathy after pressure overload, by multiple mechanisms, indicating that α 1 -signaling is required for cardiac adaptation. These results suggest that the adverse cardiac effects of α 1 -antagonists in clinical trials are due to loss of α 1 -signaling in myocytes, emphasizing concern about clinical use of α 1 -antagonists, and point to a revised perspective on sympathetic activation in heart failure.

Background and Aims. Embryonic stem (ES) cellshave a pluripotent ability to differentiate into a variety of cell lineages in vitro. We have recently identified the emergence of cellular clusters within differentiated ES cell cultures by staining with dithizone (DTZ). DTZ is a zinc-chelating agent known to selectively stain pancreatic beta cells because of their high zinc content. The aim of the present study was to investigate the characteristics of DTZ-stained cellular clusters originating from ES cells.Methods. Embryoid bodies (EBs), formed by a 5-day hanging drop culture of ES cells, were allowed to form outgrowths in the culture. The outgrowths were incubated in DTZ solution (final concentration, 100 µg/ml ) for 15 minutes before being examined microscopically. The gene expression of endocrine pancreatic markers was also analyzed by reverse transcriptase-polymerase chain reaction. In addition, insulin production was

Ursodeoxycholic acid was recently recognized as an effective agent in the treatment of primary biliary cirrhosis. Experimental evidence supporting the usefulness of ursodeoxycholic acid as a potentially beneficial therapeutic agent for primary biliary cirrhosis has been reported from the biochemical and physiological aspects. In this study, we investigated the direct effects of ursodeoxycholic acid on immunoglobulin and cytokine production in vitro using plaque-forming cell assay and enzyme-linked immunosorbent assay. It was demonstrated that ursodeoxycholic acid suppressed the production of IgM, IgG and IgA induced by Staphylococcus aureus Cowan I in peripheral blood mononuclear cells derived from healthy subjects and patients with primary biliary cirrhosis and also in human B lymphoma cell lines. Furthermore, ursodeoxycholic acid suppressed interleukin-2 and interleukin-4 production induced by concanavalin A and interferon-gamma production induced by polyinosinic-polycytidylic acid, but it did not affect interleukin-1 and interleukin-6 production induced by lipopolysaccharide in peripheral blood mononuclear cells. In addition, ursodeoxycholic acid suppressed the concanavalin A-induced thymocyte proliferation mediated by interleukin-1. Cytotoxicity against lymphocytes was not observed at the concentrations of ursodeoxycholic acid used. These results suggest that the beneficial effect of ursodeoxycholic acid in primary biliary cirrhosis is mediated in part by immunosuppression.

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To elucidate the time course of sympathovagal balance and its relationship to left ventricular function in heart failure, we serially evaluated left ventricular contractility and relaxation and autonomic tone in 11 conscious dogs with tachycardia-induced heart failure. We determined a dynamic map of sympathetic and parasympathetic modulation by power spectral analysis of heart rate variability. The left ventricular peak +dP/dt substantially fell from 3,364 +/- 338 to 1,959 +/- 318 mmHg/s (P < 0.05) on the third day and declined gradually to 1,783 +/- 312 mmHg/s at 2 wk of rapid ventricular pacing. In contrast, the time constant of left ventricular pressure decay and end-diastolic pressure increased gradually from 25 +/- 4 to 47 +/- 5 ms (P < 0.05) and from 10 +/- 2 to 21 +/- 3 mmHg (P < 0.05), respectively, at 2 wk of pacing. The high-frequency component (0.15-1.0 Hz), a marker of parasympathetic modulation, decreased from 1,928 +/- 1,914 to 62 +/- 68 x 10(3) ms2 (P < 0.05) on the third day and further to 9 +/- 12 x 10(3) ms2 (P < 0.05) at 2 wk. Similar to the time course of left ventricular diastolic dysfunction, plasma norepinephrine levels and the ratio of low (0.05- to 0.15-Hz)- to high-frequency component increased progressively from 135 +/- 50 to 532 +/- 186 pg/ml (P < 0.05) and from 0.06 +/- 0.06 to 1.12 +/- 1.01 (P < 0.05), respectively, at 2 wk of pacing. These cardiac and autonomic dysfunctions recovered gradually toward the normal values at 2 wk after cessation of pacing. Thus a parallel decline in left ventricular contractility with parasympathetic influence and a parallel progression in left ventricular diastolic dysfunction with sympathoexcitation suggest a close relationship between cardiac dysfunction and autonomic dysregulation during development of heart failure.

Background and Aims. Embryonic stem (ES) cellshave a pluripotent ability to differentiate into a variety of cell lineages in vitro. We have recently found that ES cells can give rise to a functional gut-like unit, which forms a three-dimensional dome-like structure with lumen and exhibits mechanical activity, such as spontaneous contraction and peristalsis. The aim of the present study was to investigate the electrophysiological and morphological properties of ES cell-derived contracting clusters.Methods. Electrical activity was examined by an extracellular recording. Morphology and cellular components were investigated by immunohistochemistry and electron microscopy.Results. Clusters with rhythmic contractions displayed electrical slow waves at a regular rhythm, and clusters with highly coordinated peristalsis showed regular slow