Immunohistochemical demonstration of urotensins I and II in the caudal neurosecretory system of the Japanese charr,Salvelinus leucomaenis,retained in sea water

This paper is concerned with part of the role and function of the caudal neurosecretory system of the charr,Salvelinus leucomaenis, studied by immunohistochemistry. In order to elucidate the different histologic changes, we examined the immunoreactivities of urotenisn I (UI) and urotensin II (UII) in 3 experimental groups: the feral (river) fish, the fresh-water aquarium-, and sea water aquarium-retained fish. Coexistence of UI and UII was demonstrated in most of the smaller and larger neurons distributed in and near the urophyseal system of all 3 groups. However, some of the larger neurons were immunoreactive only to a single hormone, UI or UII. Merely a few neurons indicated no reactivity for either UI or UII. No such clearcut differences were encountered immunohistochemically in the 3 groups. Neuronal and urophysial immuno-reactivity to UI of feral and fresh-water-retained fish was slightly stronger than that of sea water-retained fish. Moreover, in sea water-retained fish, the intensity of immunoreactivity for UI was variable, and the number of neurons positive for UII only was somewhat larger than that in feral and fresh-water-retained fish. A series of UII-positive cerebrospinal fluid (CSF)-contacting neurons were seen in the ependymal and subependymal layers ventral to the central canal of the spinal cord in every group. These CSF-contacting neurons might constitute another neurosecretory system aside from the ordinary caudal neurosecretory system equipped with urophysis. In contrast to the hypothalamohypophysial neurosecretory system, the caudal neurosecretory system did not show any significant changes among the 3 groups. This suggests that urotensins I and II have no essential role in osmoregulation of the charr.     

The development of emotion regulation ability between the ages of 13 and 18 months in Japanese infants during the strange situation as a function of mothers' styles of emotion expression

The purposes of this study were two-fold. First, it compared Japanese infants' (N=129) abilities to regulate emotions at 13 months and 18 months of age, using the Strange Situation procedure. Second, it examined the relationship between the development of emotion regulation and the mother's emotion expression style as assessed by the Emotion Expression Style Questionnaire (EESQ). The total number of subjects who successfully completed all 8 episodes of the Strange Situation procedure increased significantly during the aging between 13 and 18 months of age, indicating that as a group these infants increased their ability to cope with stressful situations. However, infants who had mothers with negative emotion expression styles did not show greater capacity for emotion regulation at 18 months. These findings suggest that the development of emotion regulation is mediated by the mother's emotion expression style.     

Excess carotenoids disturb prospective cell-to-cell recognition system in mating responses ofPhycomyces blakesleeanus

Carotenogenic mutants ofPhycomyces, which accumulate excess β-carotene or its intermediates, always failed in zygospore development. No improvement occurred when such mutants were mated together with a helper wild type of the same mating type against the wild type of the opposite mating type. Addition of excess synthesized pheromone, trisporin B, also failed to improve the zygospore development, though the mating response was significantly activated in the early stages and abundant zygophores were formed. Exceptional acceleration of the zygospore development under these experimental conditions occurred in a regulatory albino mutant (carA), which does not accumulate excess intermediate carotenoids. Chemically- or genetically-induced ovarproduction of β-carotene or lycopene also inhibited the zygospore development. These results imply that the zygospore development ofPhycomyces is maximal when the intracellular amount of β-carotene is optimal (=wild type), and that pheromones act mainly in the early stages of mating, while other factors such as the cell-to-cell recognition system may also be involved in the later stages. Intracellular accumulation of excess β-carotene or its intermediates probably disturb such later-stage factors.     

Nitrotyrosine formation and its role in various pathological conditions

The formation of peroxynitrite and nitrotyrosine was examined in a variety of in vitro and in vivo animal models and its relation to cell or tissue damage was examined. In polymorphonuclear leukocyte (PMN)-induced injury to cardiac myocytes or endothelial cells, activated PMN produced peroxynitrite. Peroxynitrite appears to be responsible for the injury but it was not a major mediator of endothelial cell injury. In the experiment of ischemia-reperfusion injury of the rat brain nitrotyrosine was formed in the peri-infarct and core-of infarct regions. The degradation curve of nitrotyrosine revealed that its t1/2 was about 2.2 hours. In the radiation-induced lung injury of rats, nitrotyrosine was also formed but it was not the sole mechanism for the injury. Levels of nitrotyrosine correlated with the severity of myocardial dysfunction in the canine model of cytokine-induced cardiac injury. Inhibition of NO generation abolished the formation of peroxynitrite and nitrotyrosine in all experiments. In conclusion; although nitrotyrosine is formed in a variety of pathological conditions where the generation of NO is increased, its presence does not always correlate with the severity of injury.     

Myeloperoxidase has Directly-opposed Effects on Nitration Reaction--Study on Myeloperoxidase-deficient Patient and Myeloperoxidase-knockout Mice

Myeloperoxidase (MPO) catalyzes a nitration reaction to form nitrotyrosine in the presence of high nitrite, the metabolite of NO. Human leukocyte was shown to cause phenolic nitration using released MPO as a catalyst in the presence of nitrite. It opposes our previous finding that inhibition of MPO was essential for phenol nitration in human leukocyte study. To clarify the role of MPO, we utilized MPO-deficient human leukocytes and MPO-knockout mice. Even in the absence of exogenously added nitrite, high nitration product was observed in MPO-deficient leukocytes. In liver subjected to ischemia/reperfusion injury, a significantly higher amount of nitrotyrosine was produced in MPO-knockout mice than in normal mice. These results clearly demonstrate that MPO inhibits the accumulation of nitration products in vivo . Further experiments showed that MPO could degrade nitrotyrosine in the presence of glutathione. Thus, MPO-induced degradation of nitration products may cause the underestimation of the nitration product generated in vivo . We conclude that MPO may act predominantly to scavenge nitrotyrosine under physiological nitrite condition, and protect against injurious effect of nitrotyrosine.     

A Novel Prolyl Hydroxylase Inhibitor Protects Against Cell Death After Hypoxia

Hypoxia-inducible factor 1 (HIF-1) is regulated by the oxygen-dependent hydroxylation of proline residues by prolyl hydroxylases (PHDs). We recently developed a novel PHD inhibitor, TM6008, that suppresses the activity of PHDs, inducing continuous HIF-1α activation. In this study, we investigated how TM6008 affects cell survival after hypoxic conditions capable of inducing HIF-1α expression and how TM6008 regulates PHDs and genes downstream of HIF-1α. After SHSY-5Y cells had been subjected to hypoxia, TM6008 was added to the cell culture medium under normoxic conditions. Apoptotic cell death was significantly augmented just after the hypoxic conditions, compared with cell death under normoxic conditions. Notably, when TM6008 was added to the media after the cells had been subjected to hypoxia, the expression level of HIF-1α increased and the number of cell deaths decreased, compared with the results for cells cultured in media without TM6008 after hypoxia, during the 7-day incubation period under normoxic conditions. Moreover, the protein expression levels of heme oxygenase 1, erythropoietin, and glucose transporter-3, which were genes downstream of HIF-1α, were elevated in media to which TM6008 had been added, compared with media without TM6008, during the 7-day incubation period under normoxic conditions. However, the protein expression levels of PHD2 and p53 which suppressed cell proliferation were suppressed in the media to which TM6008 had been added. Thus, TM6008, which suppresses the protein expressions of PHD2 and p53, might play an important role in cell survival after hypoxic conditions, with possible applications as a new compound for treatment after ischemic stroke.     

Identification of 2,3-disubstituted pyridines as potent,orally active PDE4 inhibitors

A series of 2,3-disubstituted pyridines were synthesized and evaluated for their PDE4 inhibitory activity. We successfully modified undesirable cyano group of initial lead compound 2 to 4-pyridyl group with improvement of in vitro efficacy and optimized the position of nitrogen atoms in pyridine moiety and alkylene linker. The most potent compound showed significant efficacy in animal models of asthma and inflammation.     

Synthesis of ( + )-Methyl Phaseate and Its Isomer from ( — )-β-Pinene

The total synthesis of ( + )-methyI phaseate (2b) and its epimer (25) is described. The known β- ketoester (8), which was prepared from ( — )-/f-pinene (4), was converted to a key intermediate (5) via a 1, 4-dioxoester (7). The reaction of 5 with a lithium reagent of the acetylene TBDMS ether (6) in THF-HMPA at — 70°C afforded the desired acetylene alcohol (17) and its epimer (18) in high yields. 17 was transformed into ( + )-methyl phaseate (2b). From this synthetic work, the absolute configuration of natural ( — )-phaseic acid (2a) was confirmed.     

Extracts of bilberry (Vaccinium myrtillus L.) fruits improve liver steatosis and injury in mice by preventing lipid accumulation and cell death

ABSTRACT

Bilberry has been reported to have anti-oxidant and anti-inflammatory properties. We studied the effect of bilberry (Vaccinium myrtillus L.) fruits extracts (BEs) on the pathogenesis caused by lipid accumulation in fatty liver and non-alcoholic steatohepatitis (NASH). 5 μg/ml of BEs was enough to suppress lipid accumulation in the fatty liver model of the mouse hepatic AML12 cells. BEs increased cell viability and anti-oxidant capacity, presumably by activating (phosphorylating) Akt/STAT3 and inducing MnSOD/catalase. BEs also significantly reduced Rubicon and induced p62/SQSTM1, possibly contributing to reduce cellular lipids (lipophagy). When the mice were fed supplemented with BEs (5% or 10%, w/w), hepatic steatosis, injury, and hypercholesterolemia/hyperglycemia were significantly improved. Furthermore, histological and cytokine studies indicated that BEs possibly suppress hepatic inflammation (hepatitis) and fibrosis. Therefore, BEs improved liver steatosis and injury, and potentially suppress fibrosis by suppressing inflammatory response, which therefore may prevent the progression of fatty liver to NASH.