31 research outputs found

    Heliocentric Distance Dependence of Zodiacal Light Observed by Hayabusa2#

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    Zodiacal light (ZL) is sunlight scattered by interplanetary dust particles (IDPs) at optical wavelengths. The spatial distribution of IDPs in the Solar System may hold an important key to understanding the evolution of the Solar System and material transportation within it. The number density of IDPs can be expressed as n(r)∼r−αn(r) \sim r^{-\alpha}, and the exponent α∼1.3\alpha \sim 1.3 was obtained by previous observations from interplanetary space by Helios 1/2 and Pioneer 10/11 in the 1970s and 1980s. However, no direct measurements of α\alpha based on ZL observations from interplanetary space outside Earth's orbit have been performed since then. Here, we introduce initial results for the radial profile of the ZL at optical wavelengths observed over the range 0.76-1.06 au by ONC-T aboard the Hayabusa2# mission in 2021-2022. The ZL brightness we obtained is well reproduced by a model brightness, although there is a small excess of the observed ZL brightness over the model brightness at around 0.9 au. The radial power-law index we obtained is α=1.30±0.08\alpha = 1.30 \pm 0.08, which is consistent with previous results based on ZL observations. The dominant source of uncertainty arises from the uncertainty in estimating the diffuse Galactic light (DGL).Comment: 22 pages, 19 figures, 4 tables, accepted for publication by Earth, Planets and Spac

    Prostaglandin D2 Added during the Differentiation of 3T3-L1 Cells Suppresses Adipogenesis via Dysfunction of D-Prostanoid Receptor P1 and P2

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    We previously reported that the addition of prostaglandin, (PG)D2, and its chemically stable analog, 11-deoxy-11-methylene-PGD2 (11d-11m-PGD2), during the maturation phase of 3T3-L1 cells promotes adipogenesis. In the present study, we aimed to elucidate the effects of the addition of PGD2 or 11d-11m-PGD2 to 3T3-L1 cells during the differentiation phase on adipogenesis. We found that both PGD2 and 11d-11m-PGD2 suppressed adipogenesis through the downregulation of peroxisome proliferator-activated receptor gamma (PPARγ) expression. However, the latter suppressed adipogenesis more potently than PGD2, most likely because of its higher resistance to spontaneous transformation into PGJ2 derivatives. In addition, this anti-adipogenic effect was attenuated by the coexistence of an IP receptor agonist, suggesting that the effect depends on the intensity of the signaling from the IP receptor. The D-prostanoid receptors 1 (DP1) and 2 (DP2, also known as a chemoattractant receptor-homologous molecule expressed on Th2 cells) are receptors for PGD2. The inhibitory effects of PGD2 and 11d-11m-PGD2 on adipogenesis were slightly attenuated by a DP2 agonist. Furthermore, the addition of PGD2 and 11d-11m-PGD2 during the differentiation phase reduced the DP1 and DP2 expression during the maturation phase. Overall, these results indicated that the addition of PGD2 or 11d-11m-PGD2 during the differentiation phase suppresses adipogenesis via the dysfunction of DP1 and DP2. Therefore, unidentified receptor(s) for both molecules may be involved in the suppression of adipogenesis

    Prostaglandin D<sub>2</sub> Added during the Differentiation of 3T3-L1 Cells Suppresses Adipogenesis via Dysfunction of D-Prostanoid Receptor P1 and P2

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    We previously reported that the addition of prostaglandin, (PG)D2, and its chemically stable analog, 11-deoxy-11-methylene-PGD2 (11d-11m-PGD2), during the maturation phase of 3T3-L1 cells promotes adipogenesis. In the present study, we aimed to elucidate the effects of the addition of PGD2 or 11d-11m-PGD2 to 3T3-L1 cells during the differentiation phase on adipogenesis. We found that both PGD2 and 11d-11m-PGD2 suppressed adipogenesis through the downregulation of peroxisome proliferator-activated receptor gamma (PPARγ) expression. However, the latter suppressed adipogenesis more potently than PGD2, most likely because of its higher resistance to spontaneous transformation into PGJ2 derivatives. In addition, this anti-adipogenic effect was attenuated by the coexistence of an IP receptor agonist, suggesting that the effect depends on the intensity of the signaling from the IP receptor. The D-prostanoid receptors 1 (DP1) and 2 (DP2, also known as a chemoattractant receptor-homologous molecule expressed on Th2 cells) are receptors for PGD2. The inhibitory effects of PGD2 and 11d-11m-PGD2 on adipogenesis were slightly attenuated by a DP2 agonist. Furthermore, the addition of PGD2 and 11d-11m-PGD2 during the differentiation phase reduced the DP1 and DP2 expression during the maturation phase. Overall, these results indicated that the addition of PGD2 or 11d-11m-PGD2 during the differentiation phase suppresses adipogenesis via the dysfunction of DP1 and DP2. Therefore, unidentified receptor(s) for both molecules may be involved in the suppression of adipogenesis

    Arachidonic Acid Added during the Differentiation Phase of 3T3-L1 Cells Exerts Anti-Adipogenic Effect by Reducing the Effects of Pro-Adipogenic Prostaglandins

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    A linoleic acid (LA) metabolite arachidonic acid (AA) added to 3T3-L1 cells is reported to suppress adipogenesis. The purpose of the present study aimed to clarify the effects of AA added during the differentiation phase, including adipogenesis, the types of prostaglandins (PG)s produced, and the crosstalk between AA and the PGs produced. Adipogenesis was inhibited by AA added, while LA did not. When AA was added, increased PGE2 and PGF2&alpha; production, unchanged &Delta;12-PGJ2 production, and reduced PGI2 production were observed. Since the decreased PGI2 production was reflected in decreased CCAAT/enhancer-binding protein-&beta; (C/EBP&beta;) and C/EBP&delta; expression, we expected that the coexistence of PGI2 with AA would suppress the anti-adipogenic effects of AA. However, the coexistence of PGI2 with AA did not attenuate the anti-adipogenic effects of AA. In addition, the results were similar when &Delta;12-PGJ2 coexisted with AA. Taken together, these results indicated that the metabolism of ingested LA to AA is necessary to inhibit adipogenesis and that exposure of AA to adipocytes during only the differentiation phase is sufficient. As further mechanisms for suppressing adipogenesis, AA was found not only to increase PGE2 and PGF2&alpha; and decrease PGI2 production but also to abrogate the pro-adipogenic effects of PGI2 and &Delta;12-PGJ2

    Arachidonic Acid Added during the Differentiation Phase of 3T3-L1 Cells Exerts Anti-Adipogenic Effect by Reducing the Effects of Pro-Adipogenic Prostaglandins

    No full text
    A linoleic acid (LA) metabolite arachidonic acid (AA) added to 3T3-L1 cells is reported to suppress adipogenesis. The purpose of the present study aimed to clarify the effects of AA added during the differentiation phase, including adipogenesis, the types of prostaglandins (PG)s produced, and the crosstalk between AA and the PGs produced. Adipogenesis was inhibited by AA added, while LA did not. When AA was added, increased PGE2 and PGF2α production, unchanged Δ12-PGJ2 production, and reduced PGI2 production were observed. Since the decreased PGI2 production was reflected in decreased CCAAT/enhancer-binding protein-β (C/EBPβ) and C/EBPδ expression, we expected that the coexistence of PGI2 with AA would suppress the anti-adipogenic effects of AA. However, the coexistence of PGI2 with AA did not attenuate the anti-adipogenic effects of AA. In addition, the results were similar when Δ12-PGJ2 coexisted with AA. Taken together, these results indicated that the metabolism of ingested LA to AA is necessary to inhibit adipogenesis and that exposure of AA to adipocytes during only the differentiation phase is sufficient. As further mechanisms for suppressing adipogenesis, AA was found not only to increase PGE2 and PGF2α and decrease PGI2 production but also to abrogate the pro-adipogenic effects of PGI2 and Δ12-PGJ2

    The tyrosine-sorting motif of the vacuolar sorting receptor VSR4 from <i>Arabidopsis thaliana</i>, which is involved in the interaction between VSR4 and AP1M2, μ1-adaptin type 2 of clathrin adaptor complex 1 subunits, participates in the post-Golgi sorting of VSR4

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    <p>μ1-Adaptin of adaptor protein (AP) 1 complex, AP1M, is generally accepted to load cargo proteins into clathrin-coated vesicles (CCVs) at the <i>trans</i>-Golgi network through its binding to cargo-recognition sequences (CRSs). Plant vacuolar-sorting receptors (VSRs) function in sorting vacuolar proteins, which are reportedly mediated by CCV. We herein investigated the involvement of CRSs of <i>Arabidopsis thaliana</i> VSR4 in the sorting of VSR4. The results obtained showed the increased localization of VSR4 at the plasma membrane or vacuoles by mutations in CRSs including the tyrosine-sorting motif YMPL or acidic dileucine-like motif EIRAIM, respectively. Interaction analysis using the bimolecular fluorescence complementation (BiFC) system, V10-BiFC, which we developed, indicated an interaction between VSR4 and AP1M2, AP1M type 2, which was attenuated by a YMPL mutation, but not influenced by an EIRAIM mutation. These results demonstrated the significance of the recognition of YMPL in VSR4 by AP1M2 for the post-Golgi sorting of VSR4.</p> <p>Clathrin AP1M2-recognizable tyrosine motif for plant VSR4 sorting.</p
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