89 research outputs found

    Activities of bone morphogenetic proteins in prolactin regulation by somatostatin analogs in rat pituitary GH3 cells

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    Involvement of the pituitary BMP system in the modulation of prolactin (PRL) secretion regulated by somatostatin analogs, including octreotide (OCT) and pasireotide (SOM230), and a dopamine agonist, bromocriptine (BRC), was examined in GH3 cells. GH3 cells are rat pituitary somato-lactotrope tumor cells that express somatostatin receptors (SSTRs) and BMP system molecules including BMP-4 and -6. Treatment with BMP-4 and -6 increased PRL and cAMP secretion by GH3 cells. The BMP-4 effects were neutralized by adding a BMP-binding protein Noggin. These findings suggest the activity of endogenous BMPs in augmenting PRL secretion by GH3 cells. BRC and SOM230 reduced PRL secretion, but OCT failed to reduce the PRL level. In GH3 cells activated by forskolin, BRC suppressed forskolin-induced PRL secretion with reduction in cAMP levels. OCT did not affect forskolin-induced PRL level, while SOM230 reduced PRL secretion and PRL mRNA expression induced by forskolin. BMP-4 treatment enhanced the reducing effect of SOM230 on forskolin-induced PRL level while BMP-4 did not affect the effects of OCT or BRC. Noggin treatment had no significant effect on the BRC actions reducing PRL levels by GH3 cells. However, in the presence of Noggin, OCT elicited an inhibitory effect on forskolin-induced PRL secretion and PRL mRNA expression, whereas the SOM230 effect on PRL reduction was in turn impaired. It was further found that BMP-4 and -6 suppressed SSTR-2 but increased SSTR-5 mRNA expression of GH3 cells. These findings indicate that Noggin rescues SSTR-2 but downregulates SSTR-5 by neutralizing endogenous BMP actions, leading to an increase in OCT sensitivity and a decrease in SOM230 sensitivity of GH3 cells. In addition, BMP signaling was facilitated in GH3 cells treated with forskolin. Collectively, these findings suggest that BMPs elicit differential actions in the regulation of PRL release dependent on cellular cAMP-PKA activity. BMPs may play a key role in the modulation of SSTR sensitivity of somato-lactotrope cells in an autocrine/paracrine manner

    Concurrent Connection of Embryonic Chick Heart Using a Microfluidic Device for Organ-Explant-Chip

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    AbstractWe propose a concurrent microvascular connection method called suction-induced vascular fixation (SVF) method for the achievement of Organ-Explant-Chip which is a biologically-designed simulator having biological materials such as cells, tissues, and organs. The advantages of proposed method with using a microfluidic device are as follows: (1) operation of flexible objects (blood vessels), (2) alignment the blood vessels concurrently, and (3) reduction of the DOFs of the blood vessels. From the experimental results, we confirmed that four cardiovascular of the explanted embryonic chick heart can be induced into the fabricated microfluidic device concurrently. We have also succeeded in construction of hybrid circulatory system between artifacts and embryonic chick heart, and monitoring the response of the heart of chick embryo by supplying the culture medium

    Algal protein kinase, Triacylglycerol Accumulation Regulator 1, modulates cell viability and gametogenesis in carbon/nitrogen imbalanced conditions

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    Nutrient-deprived microalgae accumulate triacylglycerol (TAG) in lipid droplets. A dual-specificity tyrosine phosphorylation-regulated kinase, TAG accumulation regulator 1 (TAR1) has been shown to be required for acetate-dependent TAG accumulation and the degradation of chlorophyll and photosynthesis-related proteins in photomixotrophic nitrogen (N)-deficient conditions (Kajikawa et al. 2015). However, this previous report only examined particular condition. Here, we report that in photoautotrophic N-deficient conditions, tar1-1 cells, with a mutation in the TAR1 gene, maintained higher levels of cell viability and lower levels of hydrogen peroxide generation and accumulated higher levels of TAG and starch compared with those of wild-type (WT) cells with bubbling of air containing 5% carbon dioxide. Transcriptomic analyses suggested that genes involved in the scavenging of reactive oxygen species are not repressed in tar1-1 cells. In contrast, the mating efficiency and mRNA levels of key regulatory genes for gametogenesis, MID, MTD, and FUS, were suppressed in tar1-1 cells. Among the TAR1-dependent phosphopeptides deduced by phosphoproteomic analysis, protein kinases and enzymes related to N assimilation and carbon (C) metabolism are of particular interest. Characterization of these putative downstream factors may elucidate the molecular pathway whereby TAR1 mediates cellular propagation and C and N metabolism in C/N-imbalanced stress conditions

    A Japanese Patient with Gastric Cancer and Dihydropyrimidine Dehydrogenase Deficiency Presenting with DPYD Variants

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    A 63-year-old Japanese male with stomach adenocarcinoma received oral 5-fluorouracil derivative, cisplatin and trastuzumab chemotherapy. On day 8, severe diarrhea and mucositis developed; chemotherapy was stopped. On day 14, the patient developed renal dysfunction and febrile neutropenia. He also suffered from pneumonia due to Candida albicans. Systemic symptoms improved after intensive conservative treatment. Best supportive care was continued until the patient died from gastric cancer. The dihydropyrimidine dehydroge-nase protein level was low at 3.18 U/mg protein. The result of DPYD genotyping revealed three variants at posi-tions 1615 (G > A), 1627 (A > G), and 1896 (T > C) in exons 13, 13, and 14, respectively

    Reduced glycemic variability and flexible graft function after islet transplantation: A case report

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    To date, studies of patients with islet transplantation addressing intermittently scanned continuous glucose monitoring profile and the flexibility of the graft islet function under different doses of insulin administration, both of which reflect the real daily life of patients, are quite limited. Here, we report a case of a 46‐year‐old woman who received islet transplantation after kidney transplantation. The patient was followed up over a period of 2 years after initial islet transplantation. Our results show that intermittently scanned continuous glucose monitoring can be useful for monitoring the reduction of glycemic variability, and suggest the appropriate regulation of insulin secretion from graft islets during mixed‐meal test by using different doses of exogenous insulin administration. Additionally, during the 2‐year observational period, glucagon elevation was detected only at hypoglycemia, whereas the level was within the normal range at normoglycemia or hyperglycemia

    Mutual interaction of kisspeptin, estrogen and bone morphogenetic protein-4 activity in GnRH regulation by GT1-7 cells

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    Reproduction is integrated by interaction of neural and hormonal signals converging on hypothalamic neurons for controlling gonadotropin-releasing hormone (GnRH). Kisspeptin, the peptide product of the kiss1 gene and the endogenous agonist for the GRP54 receptor, plays a key role in the regulation of GnRH secretion. In the present study, we investigated the interaction between kisspeptin, estrogen and BMPs in the regulation of GnRH production by using mouse hypothalamic GT1-7 cells. Treatment with kisspeptin increased GnRH mRNA expression and GnRH protein production in a concentration-dependent manner. The expression levels of kiss1 and GPR54 were not changed by kisspeptin stimulation. Kisspeptin induction of GnRH was suppressed by co-treatment with BMPs, with BMP-4 action being the most potent for suppressing the kisspeptin effect. The expression of kisspeptin receptor, GPR54, was suppressed by BMPs, and this effect was reversed in the presence of kisspeptin. It was also revealed that BMP-induced Smad1/5/8 phosphorylation and Id-1 expression were suppressed and inhibitory Smad6/7 was induced by kisspeptin. In addition, estrogen induced GPR54 expression, while kisspeptin increased the expression levels of ER alpha. and ER beta, suggesting that the actions of estrogen and kisspeptin are mutually enhanced in GT1-7 cells. Moreover, kisspeptin stimulated MAPKs and AKT signaling, and ERK signaling was functionally involved in the kisspeptin-induced GnRH expression. BMP-4 was found to suppress kisspeptin-induced GnRH expression by reducing ERK signaling activity. Collectively, the results indicate that the axis of kisspeptin-induced GnRH production is bi-directionally controlled, being augmented by an interaction between ER alpha/beta and GPR54 signaling and suppressed by BMP-4 action in GT1-7 neuron cells

    Mutual interaction of kisspeptin, estrogen and bone morphogenetic protein-4 activity in GnRH regulation by GT1-7 cells

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    a b s t r a c t Reproduction is integrated by interaction of neural and hormonal signals converging on hypothalamic neurons for controlling gonadotropin-releasing hormone (GnRH). Kisspeptin, the peptide product of the kiss1 gene and the endogenous agonist for the GRP54 receptor, plays a key role in the regulation of GnRH secretion. In the present study, we investigated the interaction between kisspeptin, estrogen and BMPs in the regulation of GnRH production by using mouse hypothalamic GT1-7 cells. Treatment with kisspeptin increased GnRH mRNA expression and GnRH protein production in a concentrationdependent manner. The expression levels of kiss1 and GPR54 were not changed by kisspeptin stimulation. Kisspeptin induction of GnRH was suppressed by co-treatment with BMPs, with BMP-4 action being the most potent for suppressing the kisspeptin effect. The expression of kisspeptin receptor, GPR54, was suppressed by BMPs, and this effect was reversed in the presence of kisspeptin. It was also revealed that BMP-induced Smad1/5/8 phosphorylation and Id-1 expression were suppressed and inhibitory Smad6/7 was induced by kisspeptin. In addition, estrogen induced GPR54 expression, while kisspeptin increased the expression levels of ERa and ERb, suggesting that the actions of estrogen and kisspeptin are mutually enhanced in GT1-7 cells. Moreover, kisspeptin stimulated MAPKs and AKT signaling, and ERK signaling was functionally involved in the kisspeptin-induced GnRH expression. BMP-4 was found to suppress kisspeptin-induced GnRH expression by reducing ERK signaling activity. Collectively, the results indicate that the axis of kisspeptin-induced GnRH production is bi-directionally controlled, being augmented by an interaction between ERa/b and GPR54 signaling and suppressed by BMP-4 action in GT1-7 neuron cells

    Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

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    As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio

    Unc-51/ATG1 Controls Axonal and Dendritic Development via Kinesin-Mediated Vesicle Transport in the Drosophila Brain

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    Background:Members of the evolutionary conserved Ser/Thr kinase Unc-51 family are key regulatory proteins that control neural development in both vertebrates and invertebrates. Previous studies have suggested diverse functions for the Unc-51 protein, including axonal elongation, growth cone guidance, and synaptic vesicle transport.Methodology/Principal Findings:In this work, we have investigated the functional significance of Unc-51-mediated vesicle transport in the development of complex brain structures in Drosophila. We show that Unc-51 preferentially accumulates in newly elongating axons of the mushroom body, a center of olfactory learning in flies. Mutations in unc-51 cause disintegration of the core of the developing mushroom body, with mislocalization of Fasciclin II (Fas II), an IgG-family cell adhesion molecule important for axonal guidance and fasciculation. In unc-51 mutants, Fas II accumulates in the cell bodies, calyx, and the proximal peduncle. Furthermore, we show that mutations in unc-51 cause aberrant overshooting of dendrites in the mushroom body and the antennal lobe. Loss of unc-51 function leads to marked accumulation of Rab5 and Golgi components, whereas the localization of dendrite-specific proteins, such as Down syndrome cell adhesion molecule (DSCAM) and No distributive disjunction (Nod), remains unaltered. Genetic analyses of kinesin light chain (Klc) and unc-51 double heterozygotes suggest the importance of kinesin-mediated membrane transport for axonal and dendritic development. Moreover, our data demonstrate that loss of Klc activity causes similar axonal and dendritic defects in mushroom body neurons, recapitulating the salient feature of the developmental abnormalities caused by unc-51 mutations.Conclusions/Significance:Unc-51 plays pivotal roles in the axonal and dendritic development of the Drosophila brain. Unc-51-mediated membrane vesicle transport is important in targeted localization of guidance molecules and organelles that regulate elongation and compartmentalization of developing neurons
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