Gender Fairness: The Promotion of Gender Equality in the Philosophical Association of Japan and the Place of Female Researchers in Philosophy

広島大学応用倫理学プロジェクト研究センター研究成果報告書統一テーマ : ［平和と和解］ 《Frieden und Versöhnung》本稿は研究課題番号 16H03338 科学研究費補助金基盤（B）「哲学分野における男女共同参画と若手研究者育成に関する理論・実践的研究」の成果によるものである

Endocytic trafficking factor VPS45 is essential for spatial regulation of lens fiber differentiation in zebrafish

In vertebrate lens, lens epithelial cells cover the anterior half of the lens fiber core. Lens epithelial cells proliferate, move posteriorly and start to differentiate into lens fiber cells at the lens equator. Although FGF signaling promotes this equatorial commencement of lens fiber differentiation, the underlying mechanism is not fully understood. Here, we show that lens epithelial cells abnormally enter lens fiber differentiation without passing through the equator in zebrafish vps45 mutants. VPS45 belongs to the Sec1/Munc18-like protein family and promotes endosome trafficking, which differentially modulates signal transduction. Ectopic lens fiber differentiation in vps45 mutants does not depend on FGF, but is mediated through activation of TGFbeta signaling and inhibition of canonical Wnt signaling. Thus, VPS45 normally suppresses lens fiber differentiation in the anterior region of lens epithelium by modulating TGFbeta and canonical Wnt signaling pathways. These data indicate a novel role of endosome trafficking to ensure equator-dependent commencement of lens fiber differentiation

The BH3-Only SNARE BNip1 Mediates Photoreceptor Apoptosis in Response to Vesicular Fusion Defects

SummaryIntracellular vesicular transport is important for photoreceptor function and maintenance. However, the mechanism underlying photoreceptor degeneration in response to vesicular transport defects is unknown. Here, we report that photoreceptors undergo apoptosis in a zebrafish β-soluble N-ethylmaleimide-sensitive factor attachment protein (β-SNAP) mutant. β-SNAP cooperates with N-ethylmaleimide-sensitive factor to recycle the SNAP receptor (SNARE), a key component of the membrane fusion machinery, by disassembling the cis-SNARE complex generated in the vesicular fusion process. We found that photoreceptor apoptosis in the β-SNAP mutant was dependent on the BH3-only protein BNip1. BNip1 functions as a component of the syntaxin-18 SNARE complex and regulates retrograde transport from the Golgi to the endoplasmic reticulum. Failure to disassemble the syntaxin-18 cis-SNARE complex caused BNip1-dependent apoptosis. These data suggest that the syntaxin-18 cis-SNARE complex functions as an alarm factor that monitors vesicular fusion competence and that BNip1 transforms vesicular fusion defects into photoreceptor apoptosis

Positive allosteric modulation of the calcium-sensing receptor by physiological concentrations of glucose

The calcium-sensing receptor (CaSR) is activated by various cations, cationic compounds, and amino acids. In the present study we investigated the effect of glucose on CaSR in HEK293 cells stably expressing human CaSR (HEK-CaSR cells). When glucose concentration in the buffer was raised from 3 to 25 mM, a rapid elevation of cytoplasmic Ca2+ concentration ([Ca2+](c)) was observed. This elevation was immediate and transient and was followed by a sustained decrease in [Ca2+](c). The effect of glucose was detected at a concentration of 4 mM and reached its maximum at 5 mM. 3-O-Methylglucose, a non-metabolizable analogue of glucose, reproduced the effect of glucose. Sucrose also induced an elevation of [Ca2+](c) in HEK-CaSR cells. Similarly, sucralose was nearly as effective as glucose in inducing elevation of [Ca2+](c). Glucose was not able to increase [Ca2+](c) in the absence of extracellular Ca2+. The effect of glucose on [Ca2+](c) was inhibited by NPS-2143, an allosteric inhibitor of CaSR. In addition, NPS-2143 also inhibited the [Ca2+](c) responses to sucralose and sucrose. Glucose as well as sucralose decreased cytoplasmic cAMP concentration in HEK-CaSR cells. The reduction of cAMP induced by glucose was blocked by pertussis toxin. Likewise, sucralose reduced [cAMP](c). Finally, glucose increased [Ca2+](c) in PT-r parathyroid cells and in Madin-Darby canine kidney cells, both of which express endogenous CaSR. These results indicate that glucose acts as a positive allosteric modulator of CaSR

Critical Contribution of Nuclear Factor Erythroid 2-related Factor 2 (NRF2) to Electrophile-induced Interleukin-11 Production

Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that plays a crucial role in protection of cells from electrophile-induced toxicity through up-regulating phase II detoxifying enzymes and phase III transporters. We previously reported that oxidative stress induces up-regulation of interleukin-11 (IL-11), a member of the IL-6 family that ameliorates acetaminophen-induced liver toxicity. However, a role for IL-11 in protection of cells from electrophile-induced toxicity remains unclear. Here we show that an environmental electrophile, 1,2-naphthoquinone (1,2-NQ), but not 15d-prostaglandin J2 (PGJ2) or tert-butylhydroxyquinone (tBHQ), induced IL-11 production. Consistent with a crucial role for prolonged ERK activation in H2O2-induced IL-11 production, 1,2-NQ, but not 15d-PGJ2 or tBHQ, elicited prolonged ERK activation. Conversely, inhibition of the ERK pathway by a MEK inhibitor completely blocked 1,2-NQ-induced IL-11 production at both protein and mRNA levels, further substantiating an intimate cross-talk between ERK activation and 1,2-NQ-induced IL-11 production. Promoter analysis of the Il11 gene revealed that two AP-1 sites were essential for 1,2-NQ-induced promoter activities. Among various members of the AP-1 family, Fra-1 was up-regulated by 1,2-NQ, and its up-regulation was blocked by a MEK inhibitor. Although NRF2 was not required for H2O2-induced IL11 up-regulation, NRF2 was essential for 1,2-NQ-induced IL11 up-regulation by increasing Fra-1 proteins possibly through promoting mRNA translation of FOSL1. Finally, intraperitoneal administration of 1,2-NQ induced body weight loss in wild-type mice, which was further exacerbated in Il11ra1−/− mice compared with Il11ra1+/− mice. Together, both Fra-1 and NRF2 play crucial roles in IL-11 production that protects cells from 1,2-NQ intestinal toxicity

Induction of Tumor-specific T Cell Immunity by Anti-DR5 Antibody Therapy

Because tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) preferentially induces apoptosis in tumor cells and plays a critical role in tumor surveillance, its receptor is an attractive target for antibody-mediated tumor therapy. Here we report that a monoclonal antibody (mAb) against the mouse TRAIL receptor, DR5, exhibited potent antitumor effects against TRAIL-sensitive tumor cells in vivo by recruiting Fc receptor–expressing innate immune cells, with no apparent systemic toxicity. Administration of the agonistic anti-DR5 mAb also significantly inhibited experimental and spontaneous tumor metastases. Notably, the anti-DR5 mAb-mediated tumor rejection by innate immune cells efficiently evoked tumor-specific T cell immunity that could also eradicate TRAIL-resistant variants. These results suggested that the antibody-based therapy targeting DR5 is an efficient strategy not only to eliminate TRAIL-sensitive tumor cells, but also to induce tumor-specific T cell memory that affords a long-term protection from tumor recurrence

Lactisole: an inhibitor of the glucose-sensing receptor T1R3 expressed in pancreatic B-cells

Glucose activates the glucose-sensing receptor T1R3 and facilitates its own metabolism in pancreatic beta-cells. An inhibitor of this receptor would be helpful in elucidating the physiological function of the glucose-sensing receptor. The present study was conducted to examine whether or not lactisole can be used as an inhibitor of the glucose-sensing receptor. In MIN6 cells, in a dose-dependent manner, lactisole inhibited insulin secretion induced by sweeteners, acesulfame-K, sucralose and glycyrrhizin. The IC50 was similar to 4 mmol/l. Lactisole attenuated the elevation of cytoplasmic Ca2+ concentration ([Ca2+](c)) evoked by sucralose and acesulfame-K but did not affect the elevation of intracellular cAMP concentration ([cAMP](c)) induced by these sweeteners. Lactisole also inhibited the action of glucose in MIN6 cells. Thus, lactisole significantly reduced elevations of intracellular [NADH] and intracellular [ATP] induced by glucose, and also inhibited glucose-induced insulin secretion. To further examine the effect of lactisole on T1R3, we prepared HEK293 cells stably expressing mouse T1R3. In these cells, sucralose elevated both [Ca2+](c) and [cAMP](c). Lactisole attenuated the sucralose-induced increase in [Ca2+](c) but did not affect the elevation of [cAMP](c). Finally, lactisole inhibited insulin secretion induced by a high concentration of glucose in mouse islets. These results indicate that the mouse glucose-sensing receptor was inhibited by lactisole. Lactisole may be useful in assessing the role of the glucose-sensing receptor in mouse pancreatic beta-cells