Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
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  • Mingzhi Luo, Peili Yu, Kai Ni, Yang Jin, Lei Liu, Jingjing Li, Yan Pan ...
    2020 Volume 43 Issue 7 Pages 1027-1034
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: May 13, 2020
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    Excessive contraction of airway smooth muscle cells (ASMCs) is a hallmark feature of asthma. Intriguing, the activation of bitter taste receptor (TAS2R) in ASMCs can relax ASMCs. However, there is a lack of potent TAS2R agonists that can be used in asthma therapies since those tested agonists cannot relax ASMCs at the dose below a few hundred micromolar. Considering that sanguinarine (SA) is a bitter substance often used in small doses for the treatment of asthma in folk medicine, the present study was to determine the rapid relaxation effect of SA on ASMCs and to reveal the underlying mechanisms associated with TAS2R signaling. Here, cell stiffness, traction force, calcium signaling, cAMP levels, and the mRNA expression were evaluated by using optical magnetic twisting cytometry, traction force microscopy, Fluo-4/AM labeling, enzyme-linked immunosorbent assay (ELISA), and quantitative (q)RT-PCR, respectively. We found that 0.5 µM SA immediately decreased cell stiffness and traction force, which is comparable with the effect of 5 µM isoproterenol. In addition, 0.5 µM SA immediately increased intracellular free calcium concentration ([Ca2+]i) and decreased the mRNA expression of contractile proteins such as calponin and α-smooth muscle actin after the treatment for 24 h. Furthermore, SA-mediated decrease in cell stiffness/traction force and increase in [Ca2+]i were significantly blunted by inhibiting the TAS2Rs signaling. These findings establish the rapid relaxation effect of SA at low concentration (<1 µM) on cultured ASMCs depending on TAS2R signaling, indicating that SA might be developed as a useful bronchodilator in asthma therapy.

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  • Qiong Yang, Wengdong Ma, Kun Yu, Qi Zhang, Zaiyuan Ye, Wenjie Xia, Shu ...
    2020 Volume 43 Issue 7 Pages 1035-1045
    Published: July 01, 2020
    Released: July 01, 2020
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    The diterpenoid oridonin is an extract from the herb Rabdosia rubescens, commonly used in Traditional Chinese medicine. Oridonin has putative inhibitory activity in many human cancers. This study continued investigations into the therapeutic potential of oridonin against gastric carcinoma, and the underlying mechanism. An in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay with BGC823 cells was used to examine the cytotoxicity and apoptosis associated with oridonin treatment. RT-PCR and immunocytochemistry results showed evaluated levels of vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), integrin β3, and proliferating cell nuclear antigen (PCNA) in BGC823 cells, or BGC823 xenografts nude mice. The inhibitory effect of oridonin was determined in vivo using the xenograft model, comparing tumor weight and volume, and calculating the tumor inhibition rate. The oridonin treatment and control groups were compared for associations between microvessel density and tumor inhibition rate, VEGF mRNA, integrin β3 mRNA, and PCNA protein. The IC50s of oridonin at 12 and 72 h were 17.08 ± 2.38 and 8.76 ± 0.90 µg/mL, respectively. VEGF protein levels dramatically decreased in a time- and dose-dependent manner with oridonin treatment. BGC823 xenograft growth was notably less in the oridonin treatment groups, responding in a dose-dependent manner. After 14 d of treatment, VEGF, integrin β3, and PCNA levels were dramatically lower, and positively correlated with CD31 levels. Oridonin was associated with inhibition of BGC823 cell growth and tumor angiogenesis, in vitro and in vivo, in a dose-and-time dependent manner with lower levels of VEGF, integrin β3, and PCNA. Oridonin is a potential candidate agent for chemotherapy of gastric carcinoma.

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  • Bin Xiao, Xiaobo Huang, Qian Wang, Yanchuan Wu
    2020 Volume 43 Issue 7 Pages 1046-1051
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: April 22, 2020
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    Supplementary material

    Beta-asarone (β-Asarone), the major component of Acorus tatarinowii Rhizoma, has been proved to be muti-pharmacological activities including anti-inflammation, and which is effective in protecting the central nervous system. However, the effect of β-Asarone on myocardial ischemia–reperfusion (I/R) injury is not yet clear. This study used a rat model with 45 min occlusion and 24 h releasing of proximal segment of left anterior descending coronary artery. The effects of β-Asarone on cardiac histopathology, myocardial infarction size, levels of cardiac troponin T (cTNT), myeloperoxidase (MPO) and interleukin-1β (IL-1β), protein expressions of apoptosis-associated speck-like protein containing a CARD (ASC), Nod-like receptor protein 3 (NLRP3), caspase-1 and Gasdermin D (GSDMSD), and left ventricular performance were studied respectively. Our results showed that administration of β-Asarone significantly improved the heart outcome after myocardial ischemia and reperfusion in terms of less infarction size and lower serum cTNT concentration. Further, β-Asarone treatment evidently inhibited inflammatory response with less granulocyte infiltration, mild tissue edema and lower tissue MPO content, it also suppressed NLRP3 signal pathway and cardiac cell’s pyroptosis for less protein expressions of ASC and NLRP3, lower level cleavage activation of caspase-1 and GSDMSD, and lower serum IL-1β concentration. Finally, β-Asarone treatment well preserved the left ventricular performance with higher ejection fraction and fractional shortening. The experimental results suggested that β-Asarone was protective against myocardial ischemia–reperfusion injury, in which inhibition of inflammatory response and suppression of NLRP3 inflammasome mediated pyroptosis were supposed to play a vital role.

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  • Xiangcui Gong, Di Sun, Zhenghao Li, Qing Shi, Dong Li, Xiuli Ju
    2020 Volume 43 Issue 7 Pages 1052-1060
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: April 21, 2020
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    Supplementary material

    Mesenchymal stem cells (MSCs) can effectively regulate immune cell functions and therefore are promising for the treatment of autoimmune disorders, such as immune thrombocytopenia (ITP). Recent research has shown that three-dimensional (3D) culture method have many advantages over conventional culture with respect to MSC secretion and immunogenicity. In this study, 2D and 3D cultured MSCs were used to evaluate cytokine secretion, extracellular matrix (ECM) gene expression, immune regulatory activity, and therapeutic effects in a mouse model of ITP. MSCs cultured on scaffolds had higher expression levels of immune regulatory genes, such as IDO1, HLA-G, and PTGS2, and greater inhibitory activity against lymphocyte activation that those of 2D-MSCs. In addition, 3D-MSCs exhibited higher ECM expression and greater protection against interferon-γ (IFN-γ)-induced apoptosis. In a mouse study, ITP was induced by guinea pig anti-mouse platelet serum injections. Based on enzyme-linked immunosorbent assays, serum levels of the suppressive cytokine interleukin (IL)-10 were higher and IFN-γ levels were lower after intravenous injection with 3D-MSCs and with 2D-MSCs. Additionally, 3D-MSCs improved the body weight, spleen index, and platelet index relative to those for 2D-MSCs. Bone marrow homing was also significantly enhanced in the 3D group. Therefore, the 3D culture of MSCs is an effective technique for the treatment of ITP.

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  • Xinxin Du, Mingxia Li, Yi Zhou, Hao Yang, Vladimir Isachenko, Tatsuya ...
    2020 Volume 43 Issue 7 Pages 1061-1066
    Published: July 01, 2020
    Released: July 01, 2020
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    This study aims to evaluate the association between passive smoking and high-grade squamous intraepithelial lesion (HSIL) at the sample of Chinese women. We conducted a case-control study to analyze the effect of passive smoking on the incidence that patients diagnosed with HSIL. The participants had undergone cervical cancer screening by cytology and human papillomavirus (HPV) co-testing within a year before the study. Multiple logistic regression was used to explore the effect and interactive effect of risk factors on HSIL. The odds ratio (OR) and 95% confidence interval (CI) were calculated. Passive smokers were 1.57 times (95% CI 1.05–2.35) higher than non-smokers to occur HSIL. The medium of the combined smoking index divided patients into low and high exposure, with the ORs of 1.64 (95%CI 1.02–2.64) and 1.71 (95%CI 1.06–2.77) relative to non-smokers, respectively. The combined smokers in the high exposure group experienced the most considerable risk of HSIL (OR = 4.67; 95%CI 1.17–18.70). The OR of HPV positive passive smoker relative to that of HPV negative non-smokers was 5.28 (95%CI 2.25–14.52;). Passive smokers who reported adolescent exposure history was 4.04 times (95%CI 1.44–11.37) more at risk of the disease than non-smokers. This study supported that passive smoking was a significant independent risk factor on the occurrence of HSIL and showed a positive correlated dose-response relationship. HPV infection interacting with passive smoking led to an even higher risk of the disease. Adolescent exposure to passive smoking persistent for more than 20 years would also increase the risk of HSIL.

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    Editor’s picks

    The association between risk factors and occurrence or development of cervical intraepithelial lesions, such as persistent infection with high-risk human papillomavirus (HPV), multiple sexual partners and smoking have been discussed. However, the effect of passive smoking on the disease is unclear. In this case-control study, Du et al. found that passive smoking was a significant independent risk factor on the occurrence of HSIL and showed a positive correlated dose-response relationship. HPV infection interacting with passive smoking led to an even higher disease risk. Adolescent exposure to passive smoking persistent for more than 20 years would also increase the HSIL risk.

  • Hajime Miyanishi, Kyosuke Uno, Mina Iwata, Yuu Kikuchi, Hidenaga Yamam ...
    2020 Volume 43 Issue 7 Pages 1067-1072
    Published: July 01, 2020
    Released: July 01, 2020
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    Major depressive disorder (MDD) is one of the most common psychiatric diseases. However, early detection and diagnosis of MDD is difficult, largely because there is no known biomarker or objective diagnostic examination, and its diagnosis is instead based on a clinical interview. The aim of this study was to develop a novel diagnostic tool using DNA methylation as a blood biomarker. We sought to determine whether unmedicated patients with MDD showed significant differences in DNA methylation in the promoter region of the SHATI/N-acetyltransferase 8 like (SHATI/NAT8L) gene compared to healthy controls. Sixty participants with MDD were recruited from all over Japan. They were diagnosed and assessed by at least two trained psychiatrists according to DSM-5 criteria. DNA was extracted from peripheral blood. We then assessed DNA methylation of the SHATI/NAT8L promoter regions in patients with MDD by pyrosequencing. Methylation levels of the SHATI/NAT8L promoter region at CpG sites in peripheral blood from unmedicated patients were significantly higher than in healthy controls. In contrast, medicated patients with MDD showed significantly lower methylation levels in the same region compared to healthy controls. Since previous studies of DNA methylation in MDD only assessed medicated patients, the methylation status of the SHATI/NAT8L promoter region in unmedicated patients presented herein may prove useful for the diagnosis of MDD. To our knowledge, this is the first attempt to measure methylation of the SHATI/NAT8L gene in drug-naïve patients with psychiatric diseases. Based on our findings, methylation of SHATI/NAT8L DNA might be a diagnostic biomarker of MDD.

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  • Nozomi Tagai, Ayako Tanaka, Akira Sato, Fumiaki Uchiumi, Sei-ichi Tanu ...
    2020 Volume 43 Issue 7 Pages 1073-1080
    Published: July 01, 2020
    Released: July 01, 2020
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    Alzheimer’s disease (AD) is pathologically characterized by accumulation of amyloid β (Aβ) and hyperphosphorylated tau, and thereby induction of neuronal cell death. The Aβ-induced neuronal cell death has been shown to occur by several modes, such as apoptosis, necrosis, and necroptosis. Interestingly, in AD patients, the brain and serum levels of brain-derived neurotrophic factor (BDNF) have been reported to be significantly decreased. However, the relationship between Aβ and BDNF in the onset of AD remains to be fully understood. Here, we used neuron-like differentiated human neuroblastoma SH-SY5Y (ndSH-SY5Y) cells to study the neurotoxicity of self-aggregated Aβ1–42 peptide under different concentrations of BDNF in the culture medium. Importantly, decreasing levels of BDNF caused a considerable suppression in the extension of neurite length. Furthermore, only under low levels of BDNF, the aggregated Aβ was revealed to induce neurite fragmentation and neuronal cell death in ndSH-SY5Y cells. Notably, the aggregated Aβ and low levels of BDNF-induced neuronal cell death was characterized at least as caspase-6 dependent cell death and necroptosis. These results indicate that our ndSH-SY5Y cell system, cultured under decreasing levels of BDNF and aggregated Aβ, has the potential to be applied in the analysis of the molecular mechanisms of the progressive neurodegenerative processes of AD and the discovery of neuroprotective drug candidates.

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  • Tomohiro Izumisawa, Nobuyuki Wakui, Tomoyoshi Kaneko, Masakazu Soma, M ...
    2020 Volume 43 Issue 7 Pages 1081-1087
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: April 14, 2020
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    Vancomycin (VAN) is an anti-microbial agent used to treat a number of bacterial infections, which has a high incidence of nephrotoxicity. We examined the pharmacokinetics of VAN retrospectively based on trough concentrations at large scale and identified pharmacokinetic differences between Japanese patients having solid malignancy and non-malignancy patients. Data were analyzed from 162 solid malignancy patients and 261 non-malignancy patients, including the patient’s background, VAN dose, and pharmacokinetics of VAN. We failed to detect differences in values for VAN clearance or shorter elimination half-lives between these two groups. In contrast, multiple regression analysis under adjusting for confounding factors by propensity score, showed that VAN clearance significantly increased in relation to solid malignancies in each stage. We conclude that VAN clearance in solid malignancy patients is increased and that the blood concentration of VAN becomes lower than expected. These results suggest that early monitoring of VAN levels in solid malignancy patients might be essential for maintaining desired effects without side-effects.

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  • Daichi Onozato, Takumi Akagawa, Yuriko Kida, Isamu Ogawa, Tadahiro Has ...
    2020 Volume 43 Issue 7 Pages 1088-1095
    Published: July 01, 2020
    Released: July 01, 2020
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    Inflammatory bowel disease, which typically manifests as Crohn’s disease and ulcerative colitis, is caused by the abnormal production of cytokines such as tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β. These cytokines damage intestinal epithelial cells and trigger fibrosis, respectively, for which the current in vitro models have many limitations. Therefore, we tested whether human induced pluripotent stem cell-derived intestinal organoids (HiOs) can mimic inflammatory bowel disease (IBD), and whether such a model is suitable for drug screening. HiOs were treated with TNF-α and TGF-β to construct mucosal damage and fibrosis models. TNF-α diminished the mRNA expression of intestinal epithelial cell and goblet cell markers in HiOs. TNF-α also induced epithelial cell damage and degradation of tight junctions but not in the presence of infliximab, an antibody used in the clinic to deplete TNF-α. Furthermore, permeation of the non-absorbable marker FD-4 was observed in HiOs treated with TNF-α or ethylene glycol tetraacetic acid (EGTA), but not in the presence of infliximab. In contrast, TNF-α and TGF-β induced mRNA expression of mesenchymal and fibrosis markers, as well as epithelial–mesenchymal transition. SB431542, a TGF-β inhibitor, significantly reversed these events. The data indicate that HiOs mimic mucosal damage and fibrosis due to IBD and are thus suitable models for drug screening.

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  • Atsushi Morii, Syouichi Katayama, Tetsuya Inazu
    2020 Volume 43 Issue 7 Pages 1096-1103
    Published: July 01, 2020
    Released: July 01, 2020
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    P19 pluripotent embryonic carcinoma (EC) stem cells are derived from pluripotent germ cell tumours and can differentiate into three germ layers. Treatment of these cells in suspension culture with retinoic acid induces their differentiation into neurons and glial cells. Hence, these cells are an excellent in vitro model to study the transition from the upper blastoderm to the neuroectoderm. However, because of the complex nature of the techniques involved, the results are highly dependent on the skills of the experimenter. Herein, we developed a simple method to induce neuronal differentiation of adherent P19 EC cells in TaKaRa NDiff® 227 serum-free medium (originally N2B27 medium). This medium markedly induced neuronal differentiation of P19 EC cells. The addition of retinoic acid to the NDiff® 227 medium further enhanced differentiation. Furthermore, cells differentiated by the conventional method, as well as the new method, showed identical expression of the mature neuronal marker, neuronal nuclei. To determine whether our approach could be applied for neuronal studies, we measured histone deacetylase 8 (HDAC8) activity using an HDAC8 inhibitor and HDAC8-knockout P19 EC cells. Inhibition of HDAC8 activity suppressed neuronal maturation. Additionally, HDAC8-knockout cell lines showed immature differentiation compared to the wild-type cell line. These results indicate that HDAC8 directly regulates the neuronal differentiation of P19 EC cells. Thus, our method involving P19 EC cells can be used as an experimental system to study the nervous system. Moreover, this method is suitable for screening drugs that affect the nervous system and cell differentiation.

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  • Seok-Hee Lim, Bing Si Li, Ri Zhe Zhu, Jae-Ho Seo, Byung-Min Choi
    2020 Volume 43 Issue 7 Pages 1104-1110
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: May 12, 2020
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    Latifolin, a natural flavonoid found in Dalbergia odorifera T. Chen, has been reported to exhibit anti-inflammatory and anticarcinogenic activities in vitro. However, the anti-aging effects of latifolin are unknown. In this study, we selected a model in vitro system, hydrogen peroxide (H2O2)-induced senescence in human dermal fibroblasts (HDFs), to examine the protective effects of latifolin against senescence and the detailed molecular mechanisms involved. Latifolin reversed the senescence-like phenotypes of the oxidant-challenged model, including senescence-associated β-galactosidase (SA-β-gal) staining, cell proliferation, and the expression of senescence-related proteins, such as caveolin-1, ac-p53, p21Cip1/WAF1, p16Ink4α, pRb, and cyclinD1. We also found that latifolin induced the expression of silent information regulator 1 (SIRT1) in a concentration- and time-dependent manner, and the anti-senescence effect of latifolin was abrogated by SIRT1 inhibition. Latifolin also suppressed the activation of Akt and S6K1 and attenuated the increase in SA-β-gal activity after H2O2 exposure. Our results indicate that latifolin exerts protective effects against senescence in HDFs and that induction of SIRT1 and inhibition of the mammalian target of rapamycin (mTOR) pathway are key mediators of its anti-aging effects.

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    Editor’s picks

    Aging is the most important risk factor for various diseases such as cancer, osteoarthritis, dementia, atherosclerosis, and infection. Therefore, the researchers has attempted to find phytochemicals for ameliorating aging-related diseased. Latifolin, isolated from Dalbergia odorifera T. Chen, has been reported to exhibit anti-inflammatory and anti-carcinogenic activities. In present study, the authors investigated the anti-aging effect of latifolin in human dermal fibroblasts. Modulation of SIRT1 may be involved in latifolin protective effect against H2O2-induced oxidant injury. These results suggest that latifolin supplementation might be a possible route for improving aging and age-related diseases.

  • Tsugunobu Andoh, Kazunari Suzuki, Mitsuhiro Konno, Koichi Tsuneyama, Y ...
    2020 Volume 43 Issue 7 Pages 1111-1117
    Published: July 01, 2020
    Released: July 01, 2020
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    Patients with cholestatic liver diseases, such as primary biliary cirrhosis, usually suffer from pruritus. However, the pathogenesis of cholestatic pruritus is unclear, and there is no current effective treatment for it. In order to find a treatment for the condition, an appropriate mouse model should be developed. Therefore, here, we established a surgically-induced mouse model of cholestatic pruritus. The bile duct was ligated in order to block bile secretion from the anterior, right, and left lobes, with the exception of the caudate lobe. Serum levels of total bile acid increased after bile duct ligation (BDL). The spontaneous hind paw scratching was also increased in BDL mice. Spontaneous scratching was reduced in BDL mice by naloxone (µ-opioid receptor antagonist), U-50,488H (κ-opioid receptor agonist), and clonidine (α2-adrenoceptor agonist). Azelastine (H1 receptor antagonist with membrane-stabilizing activity) slightly reduced scratching. However, terfenadine (H1 receptor antagonist), methysergide (serotonin (5-HT)2 receptor antagonist), ondansetron (5-HT3 receptor antagonist), proteinase-activated receptor 2-neutralizing antibody, fluvoxamine (selective serotonin reuptake inhibitor), milnacipran (serotonin-noradrenalin reuptake inhibitor), and cyproheptadine (H1 and 5-HT2 receptor antagonist) did not affect scratching. These results suggested that partial obstruction of bile secretion in mice induced anti-histamine-resistant itching and that central opioid system is involved in cholestatic itching.

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    Editor’s picks

    Patients with cholestatic liver diseases, such as primary biliary cirrhosis, usually suffer from pruritus. However, the pathogenesis of cholestatic pruritus is unclear, and there is no current effective treatment for it. In order to find a treatment for the condition, an appropriate mouse model should be developed. Andoh et al. established a surgically-induced mouse model of cholestatic pruritus and evaluated anti-pruritic effects of several drugs using this mouse model. In results, they suggested that partial obstruction of bile secretion in mice induced anti-histamine-resistant itching and that central opioid system is involved in cholestatic itching.

  • Sayuri Noda, Yoshiaki Suzuki, Hisao Yamamura, Yuji Imaizumi
    2020 Volume 43 Issue 7 Pages 1118-1122
    Published: July 01, 2020
    Released: July 01, 2020
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    Large conductance Ca2+-activated K+ (BKCa) channels are ubiquitously expressed in plasma membrane of both excitable and non-excitable cells and possess significant physiological functions. A tetrameric complex of α subunit (BKα) forms a functional pore of BKCa channel. The properties of BKCa channel, such as voltage-dependence, Ca2+ sensitivity and pharmacological responses, are extensively modulated by co-expressing accessory β subunits (BKβ), which can associate with BKα in one to one manner. Although the functional significance of newly identified γ subunits (BKγ) has been revealed, the stoichiometry between BKα and BKγ1 remains unclear. In the present study, we utilized a single molecule fluorescence imaging with a total internal reflection fluorescence (TIRF) microscope to directly count the number of green fluorescent protein (GFP)-tagged BKγ1 (BKγ1-GFP) within a single BKCa channel complex in HEK293 cell expression system. BKγ1-GFP significantly enhanced the BK channel activity even when the intracellular Ca2+ concentration was kept lower, i.e., 10 nM, than the physiological resting level. BKγ1-GFP stably formed molecular complexes with BKα-mCherry in the plasma membrane. Counting of GFP bleaching steps revealed that a BKCa channel can contain up to four BKγ1 per channel at the maximum. These results suggest that BKγ1 forms a BKCa channel complex with BKα in a 1 : 1 stoichiometry in a human cell line.

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    Editor’s picks

    Large conductance Ca2+-activated K+ (BKCa) channels possess significant physiological functions in various types of cells. The stoichiometry between BKa and newly identified ɤ1 subunits (BKɤ1) remains unclear. Here, the authors utilized a single molecule fluorescence imaging with a total internal reflection fluorescence (TIRF) microscope to directly count the number of GFP-tagged BKɤ1 within a single BKCa channel complex in HEK293 expression system. Counting of GFP bleaching steps revealed that a BKCa channel contains mainly four BKɤ1 per channel. These results suggest that BKɤ1 forms a BKCa channel complex with BKa in a 1:1 stoichiometry in a human cell line.

  • Asami Mori, Ryo Namekawa, Kenji Sakamoto, Kunio Ishii, Tsutomu Nakahar ...
    2020 Volume 43 Issue 7 Pages 1123-1127
    Published: July 01, 2020
    Released: July 01, 2020
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    Nitric oxide (NO) is an important regulator of the retinal blood flow. The present study aimed to determine the role of voltage-gated K+ (KV) channels and ATP-sensitive K+ (KATP) channels in NO-mediated vasodilation of retinal arterioles in rats. In vivo, the retinal vasodilator responses were assessed by measuring changes in the diameter of retinal arterioles from ocular fundus images. Intravitreal injection of 4-aminopyridine (a KV channel inhibitor), but not glibenclamide (a KATP channel blocker), significantly attenuated the retinal vasodilator response to the NO donor (±)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide (NOR3). Intravitreal injection of indomethacin (a non-selective cyclooxygenase inhibitor) also reduced the NOR3-induced retinal vasodilator response. The combination of 4-aminopyridine and indomethacin produced a greater reduction in the NOR3-induced response than either agent alone. 4-Aminopyridine had no significant effect on pinacidil (a KATP channel opener)-induced response. These results suggest that the vasodilatory effects of NO are mediated, at least in part, through the activation of 4-aminopyridine-sensitive KV channels in the retinal arterioles of rats. NO exerts its dilatory effect on the retinal vasculature of rats through at least two mechanisms, activation of the KV channels and enhancement of prostaglandin production.

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  • Kazumi Yoshizawa, Narumaki Arai, Yukina Suzuki, Ayumi Fujita, Yukino T ...
    2020 Volume 43 Issue 7 Pages 1128-1134
    Published: July 01, 2020
    Released: July 01, 2020
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    We investigated whether tramadol could suppress both neuropathic and inflammatory pain in mice at the same dose level. We also examined the effects of drugs metabolized by glucuronidase, such as acetaminophen (ACAP), indomethacin, probenecid, and valproate, on the antinociceptive activity of tramadol. The administration of 5.6 or 10 mg/kg tramadol suppressed cuff-induced mechanical allodynia, but 10 mg/kg tramadol did not suppress complete Freund’s adjuvant (CFA)-induced mechanical allodynia. Although neither tramadol (10 mg/kg) nor ACAP (100 mg/kg) alone produced an antinociceptive effect, their combination suppressed CFA-induced mechanical allodynia. Moreover, pretreatment naloxone, an opioid receptor antagonist, significantly attenuated the antinociceptive effects induced by the combination of tramadol and ACAP and slowed gastrointestinal transit. Similar to ACAP, the combination of tramadol and probenecid or valproate, which has the potential to inhibit uridine 5′-diphosphate (UDP)-glucuronosyltransferase (UGT), also suppressed the CFA-induced mechanical allodynia and slowed gastrointestinal transit. We concluded that tramadol was more beneficial for the treatment of neuropathic pain than inflammatory pain. Furthermore, the antinociceptive effects of the tramadol and ACAP combination were mediated by the μ-opioid receptor, and were thought to be related, at least in part, to the accumulation of the active metabolite, M1.

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Notes
  • Aya Ueda, Shinji Toki, Chisato Kitayama, Manabu Akazawa
    2020 Volume 43 Issue 7 Pages 1135-1140
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: May 12, 2020
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    Supplementary material

    Inappropriately reduced doses (IRDs) of direct oral anticoagulants (DOACs) are common in clinical practice. We performed a retrospective review using electronic medical records of St. Marianna University School of Medicine Hospital (a 1200-bed teaching hospital in Japan) to address the prevalence of IRDs and patient-related factors that result in IRDs. We also surveyed DOAC-treated patients who were hospitalized due to a stroke during the 5-year study period to analyze the association between stroke events and IRDs. We found that one in five patients who were newly prescribed a DOAC was treated with IRDs. Patients treated with edoxaban received the most IRDs (64%, 7/11), followed by those treated with dabigatran (50%, 1/2), apixaban (32%, 19/61), and rivaroxaban (27%, 12/44). Our analysis showed that the renal function (measured as serum creatinine and creatinine clearance values) and age are possible factors influencing dose reduction. The HAS-BLED score and antiplatelet use were not associated with IRD prescription. An analysis of the 5-year hospital records revealed 20 stroke cases despite ongoing treatments with DOACs, and IRDs were noted in three of these cases. In all three cases, the patients had been on an IRD of rivaroxaban. To prevent IRDs of DOACs, we suggest that a clinical protocol be incorporated into formularies to support the prescription process.

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  • Rodi Abdalkader, Johan Unga, Kazuo Maruyama, Fumiyoshi Yamashita, Mits ...
    2020 Volume 43 Issue 7 Pages 1141-1145
    Published: July 01, 2020
    Released: July 01, 2020
    [Advance publication] Released: May 02, 2020
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    In this study, we have developed a theranostic nanocarrier that can emit heat upon the exposure to ultrasound (US) irradiation as well as the generation of a contrast signal that can be detected with ultrasonography. The prepared acoustic nanodroplets (NDs) made with liquid perfluporopentane (PFPn) had an average size of 197.7 ± 3.6 nm in diameter and were stable in vitro for 60 min. US irradiation at 2 W.cm−2 induced phase change of NDs into bubbles in vitro. On the other hand, the intra-tumor injection of NDs in combination with US irradiation induced thermal emission in situ in B16BL6 melanoma tumor implanted into mice and the emission areas have mostly covered the tumor site. Also, the combination between NDs and US irradiation has inhibited the tumor growth. Under this condition, the heat shock protein (HSP70) in tumor was significantly upregulated after 6 h of the treatment of NDs with US. Thus, we have developed a therapeutic system with multiple theranostic modalities composed of acoustic NDs and US irradiation applicable to the tumor treatment on the external surface of the body.

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