研究者業績

佐藤 洋美

Hiromi Sato

基本情報

所属
千葉大学 大学院薬学研究院 臨床薬理学研究室 准教授
学位
博士(薬学)(千葉大学)

J-GLOBAL ID
201901006027076622
researchmap会員ID
B000366799

論文

 98
  • Ryota Jin, Hideki Yoshioka, Hiromi Sato, Akihiro Hisaka
    CPT: pharmacometrics & systems pharmacology 13(4) 649-659 2024年4月  査読有り
    As Parkinson's disease (PD) progresses, there are multiple biomarker changes, and sex and genetic variants may influence the rate of progression. Data-driven, long-term disease progression model analysis may provide precise knowledge of the relationships between these risk factors and progression and would allow for the selection of appropriate diagnosis and treatment according to disease progression. To construct a long-term disease progression model of PD based on multiple biomarkers and evaluate the effects of sex and leucine-rich repeat kinase 2 (LRRK2) mutations, a technique derived from the nonlinear mixed-effects model (Statistical Restoration of Fragmented Time course [SReFT]) was applied to datasets of patients provided by the Parkinson's Progression Markers Initiative. Four biomarkers, including the Unified PD Rating Scale, were used, and a covariate analysis was performed to investigate the effects of sex and LRRK2-related mutations. A model of disease progression over ~30 years was successfully developed using patient data with a median of 6 years. Covariate analysis suggested that female sex and LRRK2 G2019S mutations were associated with 21.6% and 25.4% significantly slower progression, respectively. LRRK2 rs76904798 mutation also tended to delay disease progression by 10.4% but the difference was not significant. In conclusion, a long-term PD progression model was successfully constructed using SReFT from relatively short-term individual patient observations and depicted nonlinear changes in relevant biomarkers and their covariates, including sex and genetic variants.
  • Manisha Bhateria, Isha Taneja, Kajal Karsauliya, Ashish Kumar Sonker, Yukihiro Shibata, Hiromi Sato, Sheelendra Pratap Singh, Akihiro Hisaka
    Toxicology and applied pharmacology 484 116879-116879 2024年3月  査読有り
    In vitro methods are widely used in modern toxicological testing; however, the data cannot be directly employed for risk assessment. In vivo toxicity of chemicals can be predicted from in vitro data using physiologically based toxicokinetic (PBTK) modelling-facilitated reverse dosimetry (PBTK-RD). In this study, a minimal-PBTK model was constructed to predict the in-vivo kinetic profile of fenarimol (FNL) in rats and humans. The model was verified by comparing the observed and predicted pharmacokinetics of FNL for rats (calibrator) and further applied to humans. Using the PBTK-RD approach, the reported in vitro developmental toxicity data for FNL was translated to in vivo dose-response data to predict the assay equivalent oral dose in rats and humans. The predicted assay equivalent rat oral dose (36.46 mg/kg) was comparable to the literature reported in vivo BMD10 value (22.8 mg/kg). The model was also employed to derive the chemical-specific adjustment factor (CSAF) for interspecies toxicokinetics variability of FNL. Further, Monte Carlo simulations were performed to predict the population variability in the plasma concentration of FNL and to derive CSAF for intersubject human kinetic differences. The comparison of CSAF values for interspecies and intersubject toxicokinetic variability with their respective default values revealed that the applied uncertainty factors were adequately protective.
  • Yukako Soejima, Hideki Yoshioka, Sayuri Guro, Hiromi Sato, Hiroto Hatakeyama, Yasunori Sato, Yoshihide Fujimoto, Naohiko Anzai, Akihiro Hisaka
    Frontiers in cardiovascular medicine 11 1330235-1330235 2024年  査読有り
    BACKGROUND: The aim of this study was to identify significant factors affecting the effectiveness of exercise training using information of the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training) study. METHODS: Background factors influencing the effect of exercise training were comprehensively surveyed for 2,130 patients by multivariable Cox regression analysis with the stepwise variable selection, and only significant factors were selected that were statistically distinguished from dummy noise factors using the Boruta method. RESULTS: The analysis suggested that the use of beta-blockers, pulse pressure, hemoglobin level, electrocardiography findings, body mass index, and history of stroke at baseline potentially influenced the exercise effect on all-cause death (AD). Therefore, a hypothetical score to estimate the effect of exercise training was constructed based on the analysis. The analysis suggested that the score is useful in identifying patients for whom exercise training may be significantly effective in reducing all-caused death and hospitalization (ADH) as well as AD. Such a subpopulation accounted for approximately 40% of the overall study population. On the other hand, in approximately 45% of patients, the effect of exercise was unclear on either AD or ADH. In the remaining 15% of patients, it was estimated that the effect of exercise might be unclear for ADH and potentially rather increase AD. CONCLUSIONS: This study is the first analysis to comprehensively evaluate the effects of various factors on the outcome of exercise training in chronic heart failure, underscoring the need to carefully consider the patient's background before recommending exercise training. However, it should be noted that exercise training can improve many outcomes in a wide variety of diseases. Therefore, given the limitations involved in post-hoc analyses of a single clinical trial, the characteristics of patients to whom the results of this analysis can be applied need attention, and also further research is necessary on the relationship between the degree of exercise and the outcomes. A new clinical trial would be needed to confirm the factors detected and the appropriateness of the score.
  • Sato H, Marutani R, Takaoka R, Mori-Fegan D, Wang X, Maeda K, Kusuhara H, Suzuki H, Yoshioka H, Hisaka A
    CPT: Pharmacometrics & Systems Pharmacology 12(8) 1132-1142 2023年  査読有り筆頭著者
    In this study, the ethnic ratios (ERs) of oral clearance between Japanese and Western populations were subjected to model-based meta-analysis (MBMA) for 81 drugs evaluated in 673 clinical studies. The drugs were classified into eight groups according to the clearance mechanism, and the ER for each group was inferred together with interindividual variability (IIV), interstudy variability (ISV), and inter-drug variability within a group (IDV) using the Markov chain Monte Carlo (MCMC) method. The ER, IIV, ISV, and IDV were dependent on the clearance mechanism, and, except for particular groups such as drugs metabolized by polymorphic enzymes or their clearance mechanism is not confirmative, the ethnic difference was found to be generally small. The IIV was well-matched across ethnicities, and the ISV was approximately half of the IIV as the coefficient of variation. To adequately assess ethnic differences in oral clearance without false detections, phase I studies should be designed with full consideration of the mechanism of clearance. This study suggests that the methodology of classifying drugs based on the mechanism that causes ethnic differences and performing MBMA with statistical techniques such as MCMC analysis is helpful for a rational understanding of ethnic differences and for strategic drug development.
  • Hozuki S, Yoshioka H, Asano S, Nakamura M, Koh S, Shibata Y, Tamemoto Y, Sato H, Hisaka A
    Clinical Pharmacokinetics 2023年  査読有り
  • Tamemoto Y, Shibata Y, Hashimoto N, Sato H, Hisaka A
    Drug Metabolism and Pharmacokinetics 53 100498-100498 2023年  査読有り
  • Yoshitomo A, Asano S, Hozuki S, Tamemoto Y, Shibata Y, Hashimoto N, Takahashi K, Sasaki Y, Ozawa N, Kageyama M, Iijima T, Kazuki Y, Sato H, Hisaka A
    Drug Metabolism and Disposition 51(3) 318-328 2023年  査読有り
  • Kuretake Soejima, Hiromi Sato, Akihiro Hisaka
    Clinical pharmacokinetics 61(2) 295-305 2022年2月  査読有り
    OBJECTIVE: This study aimed to examine the magnitude of age-related change in hepatic clearance by integrating the data of multiple drugs and to compare this with renal clearance, considering associations with age-related changes in organ weight and blood flow. METHODS: The results of multiple population pharmacokinetic analyses that detected age-related clearance changes in hepatically eliminated drugs were collected. The relationship between hepatic clearance of the unbound drug and age was then analyzed using the nonlinear least-squares method, adjusting for interdrug differences. The obtained change in hepatic clearance was compared with age-related changes in liver weight and hepatic blood flow in Japanese and Westerners. For comparison, the changes in renal clearance were analyzed similarly. RESULTS: In total, 18 drugs were analyzed. The hepatic unbound clearance decreased by 32% at age 80 years and by 40% at age 90 years, compared with age 40 years, suggesting that it decreased by 0.80% per year with aging. The rate of the decrease was consistent with decreases in hepatic weight per person or blood flow per person, regardless of ethnicity and sex. Since age-related change in body weight varied somewhat by sex or ethnicity, hepatic weight per body weight was less consistent to account for age-related change in hepatic clearance. As for an index of renal clearance, the changes in inulin clearance with age were similar to those in renal blood flow, with a decrease of 0.97% per year from the age of 40 years. CONCLUSIONS: Hepatic clearance consistently decreased by 0.80% per year from the age of 40 years, with aging for multiple drugs analyzed in this study. Changes in organ weight and blood flow are considered to be primarily responsible for the age-related changes in hepatic and renal clearance.
  • 櫻田大也, 本田拓也, 石川雅之, 内田雅士, 佐藤洋美, 鈴木聡子, 東顕二郎, 山口憲孝, 鈴木紀行, 小林江梨子, 神﨑哲人, 関根祐子, 佐藤信範
    医薬品相互作用研究会 46(2) 2022年  
  • Toya Okawa, Kurumi Hara, Momoko Goto, Moe Kikuchi, Masataka Kogane, Hiroto Hatakeyama, Hiroki Tanaka, Daiki Shirane, Hidetaka Akita, Akihiro Hisaka, Hiromi Sato
    International journal of molecular sciences 22(16) 2021年8月21日  査読有り責任著者
    The second messenger 2'3'-cyclic-GMP-AMP (cGAMP) is thought to be transmitted from brain carcinomas to astrocytes via gap junctions, which functions to promote metastasis in the brain parenchyma. In the current study, we established a method to introduce cGAMP into astrocytes, which simulates the state of astrocytes that have been invaded by cGAMP around tumors. Astrocytes incorporating cGAMP were analyzed by metabolomics, which demonstrated that cGAMP increased glutamate production and astrocyte secretion. The same trend was observed for γ-aminobutyric acid (GABA). Conversely, glutamine production and secretion were decreased by cGAMP treatment. Due to the fundamental role of astrocytes in regulation of the glutamine-glutamate cycle, such metabolic changes may represent a potential mechanism and therapeutic target for alteration of the central nervous system (CNS) environment and the malignant transformation of brain carcinomas.
  • Hiromi Sato, Ayaka Shimizu, Toya Okawa, Miaki Uzu, Momoko Goto, Akihiro Hisaka
    International journal of molecular sciences 22(14) 2021年7月11日  筆頭著者責任著者
    The role of astrocytes in the periphery of metastatic brain tumors is unclear. Since astrocytes regulate central nervous metabolism, we hypothesized that changes in astrocytes induced by contact with cancer cells would appear in the metabolome of both cells and contribute to malignant transformation. Coculture of astrocytes with breast cancer cell supernatants altered glutamate (Glu)-centered arginine-proline metabolism. Similarly, the metabolome of cancer cells was also altered by astrocyte culture supernatants, and the changes were further amplified in astrocytes exposed to Glu. Inhibition of Glu uptake in astrocytes reduces the variability in cancer cells. Principal component analysis of the cancer cells revealed that all these changes were in the first principal component (PC1) axis, where the responsible metabolites were involved in the metabolism of the arginine-proline, pyrimidine, and pentose phosphate pathways. The contribution of these changes to the tumor microenvironment needs to be further pursued.
  • Ryota Takaoka, Yukako Soejima, Sayuri Guro, Hideki Yoshioka, Hiromi Sato, Hiroshi Suzuki, Akihiro Hisaka
    CPT: pharmacometrics & systems pharmacology 2021年7月4日  査読有り
    To characterize and compare various medicines for chronic heart failure (CHF), changes in circulatory physiological parameter during pharmacotherapy were investigated by a model-based meta-analysis (MBMA) of circulatory physiology. The clinical data from 61 studies mostly in patients with heart failure with reduced ejection fraction (HFrEF), reporting changes in heart rate, blood pressure, or ventricular volumes after treatment with carvedilol, metoprolol, bisoprolol, bucindolol, enalapril, aliskiren, or felodipine, were analyzed. Seven cardiac and vasculature function indices were estimated without invasive measurements using models based on appropriate assumptions, and their correlations with the mortality were assessed. Estimated myocardial oxygen consumption, a cardiac load index, correlated excellently with the mortality at 3, 6, and 12 months after treatment initiation, and it explained differences in mortality across the different medications. The analysis based on the present models were reasonably consistent with the hypothesis that the treatment of HFrEF with various medications is due to effectively reducing the cardiac load. Assessment of circulatory physiological parameters by using MBMA would be insightful for quantitative understanding of CHF treatment.
  • Satoshi Asano, Aoi Yoshitomo, Shizuka Hozuki, Hiromi Sato, Yasuhiro Kazuki, Akihiro Hisaka
    Drug metabolism and disposition: the biological fate of chemicals 2021年5月7日  査読有り
    Precise prediction of drug absorption is key to the success of new drug development and efficacious pharmacotherapy. In this study, we developed a new absorption model, the advanced translocation model (ATOM), by extending our previous model, the translocation model. ATOM reproduces the translocation of a substance in the intestinal lumen using a partial differential equation with variable dispersion and convection terms to describe natural flow and micro-mixing within the intestine, under not only fasted but also fed conditions. In comparison with ATOM, it was suggested that a conventional absorption model, advanced compartmental absorption and transit model, tends to underestimate micro-mixing in the upper intestine, and it is difficult to adequately describe movements under the fasted and fed conditions. ATOM explains the observed nonlinear absorption of midazolam successfully, with a minimal number of scaling factors. Furthermore, ATOM considers the apical and basolateral membrane permeabilities of enterocytes separately and assumes compartmentation of the lamina propria, including blood vessels, to consider intestinal blood flow appropriately. ATOM estimates changes in the intestinal availability caused by drug interaction associated with inhibition of CYP3A and P-gp in the intestine. Additionally, ATOM can estimate the drug absorption in the fed state considering delayed intestinal drug flow. Therefore, ATOM is a useful tool for the analysis of local pharmacokinetics in the gastrointestinal tract, especially for the estimation of nonlinear drug absorption that may involve various interactions with intestinal contents or other drugs. Significance Statement The advanced translocation model (ATOM) was newly developed that precisely explains various movements of intestinal contents including the fasted and fed conditions which cannot be adequately described by the current physiological pharmacokinetic models.
  • Yukihiro Shibata, Yuta Tamemoto, Sheelendra Pratap Singh, Aoi Yoshitomo, Shizuka Hozuki, Hiromi Sato, Akihiro Hisaka
    DMPK 39 100396-100396 2021年4月  査読有り
  • Shinya Kawamatsu, Ryota Jin, Shogo Araki, Hideki Yoshioka, Hiromi Sato, Yasunori Sato, Akihiro Hisaka
    Journal of clinical medicine 9(8) 2020年8月18日  査読有り
    The aim of this study was to elucidate the lifelong disease progression of chronic obstructive pulmonary disease (COPD) with biomarker changes and identify their influencing factors, by utilizing a new analysis method, Statistical Restoration of Fragmented Time-course (SReFT). Individual patient data (n = 1025) participating in the Study to Understand Mortality and MorbidITy (SUMMIT, NCT01313676), which was collected within the observational period of 4 years, were analyzed. The SReFT analysis suggested that scores of St. George's Respiratory Questionnaire and COPD assessment test, representative scores of the health-related quality of life (HRQOL) questionnaire, increased consistently for 30 years of disease progression, which was not detected by conventional analysis with a linear mixed effect model. It was estimated by the SReFT analysis that normalized forced expiratory volume in one second for age, sex, and body size (%FEV1) reduced for the initial 10 years from the onset of the disease but thereafter remained constant. The analysis of HRQOL scores and lung functions suggested that smoking cessation slowed COPD progression by approximately half and that exacerbation accelerated it considerably. In conclusion, this retrospective study utilizing SReFT elucidated the progression of COPD over 30 years and associated quantitative changes in the HRQOL scores and lung functions.
  • Licht Miyamoto, Hiromi Sato
    YAKUGAKU ZASSHI 140(8) 961-962 2020年8月1日  査読有り招待有り
  • Akihiro Hisaka, Hideki Yoshioka, Hiroto Hatakeyama, Hiromi Sato, Yoshihiro Onouchi, Naohiko Anzai
    Journal of clinical medicine 9(6) 2020年6月18日  
    Global differences in changes in the numbers of population-adjusted daily test-positive cases (NPDP) and deaths (NPDD) by COVID-19 were analyzed for 49 countries, including developed and developing countries. The changes as a proportion of national population were compared, adjusting by the beginning of test-positive cases increase (BPI) or deaths increase (BDI). Remarkable regional differences of more than 100-fold in NPDP and NPDD were observed. The trajectories of NPDD after BDI increased exponentially within 20 days in most countries. Machine learning analysis suggested that NPDD on 30 days after BDI was the highest in developed Western countries (1180 persons per hundred million), followed by countries in the Middle East (128), Latin America (97), and Asia (7). Furthermore, in Western countries with positive rates of the PCR test of less than 7.0%, the increase in NPDP was slowing-down two weeks after BPI, and subsequent NPDD was only 15% compared with those with higher positive rates, which suggested that the situation of testing might have affected the velocity of COVID-19 spread. The causes behind remarkable differences between regions possibly include genetic factors of inhabitants because distributions of the race and of the observed infection increasing rates were in good agreement globally.
  • Satoshi Tomizawa, Mizuki Tamori, Ai Tanaka, Naoya Utsumi, Hiromi Sato, Hiroto Hatakeyama, Akihiro Hisaka, Takafumi Kohama, Kazuyuki Yamagata, Takuya Honda, Hiroyuki Nakamura, Toshihiko Murayama
    Biochimica et biophysica acta. Molecular and cell biology of lipids 1865(6) 158675-158675 2020年6月  査読有り
    Ceramide kinase (CerK) phosphorylates ceramide to ceramide-1-phosphate (C1P), a bioactive sphingolipid. Since the mechanisms responsible for regulating the proliferation and migration/metastasis of cancer cells by the CerK/C1P pathway remain unclear, we conducted the present study. The knockdown of CerK in A549 lung and MCF-7 breast cancer cells (shCerK cells) increased the formation of lamellipodia, which are membrane protrusions coupled with cell migration. Mouse embryonic fibroblasts prepared from CerK-null mice also showed an enhanced formation of lamellipodia. The overexpression of CerK inhibited lamellipodium formation in A549 cells. The knockdown of CerK increased the number of cells having lamellipodia with Rac1 and the levels of active Rac1-GTP form, whereas the overexpression of CerK decreased them. CerK was located in lamellipodia after the epidermal growth factor treatment, indicating that CerK functioned there to inhibit Rac1. The migration of A549 cells was negatively regulated by CerK. An intravenous injection of A549-shCerK cells into nude mice resulted in markedly stronger metastatic responses in the lungs than an injection of control cells. The in vitro growth of A549 cells and in vivo expansion after the injection into mouse flanks were not affected by the CerK knockdown. These results suggest that the activation of CerK/C1P pathway has inhibitory roles on lamellipodium formation, migration, and metastasis of A549 lung cancer cells.
  • Hiromi Sato, Asami Funaki, Yuki Kimura, Mai Sumitomo, Hiroya Yoshida, Akiko Okumura, Hideki Fukata, Hiroshi Hosoyama, Masayuki Kuroda, Toya Okawa, Akihiro Hisaka, Koichi Ueno
    Nihon yakurigaku zasshi. Folia pharmacologica Japonica 155(4) 202-208 2020年  筆頭著者責任著者
    Extract of Cyclolepis genistoides D. Don (vernacular name Palo azul; Palo) are traditionally consumed in the Republic of Paraguay in South America for the treatment of diabetes and kidney disease, and is sold in Japan as dietary supplement. This study aimed to elucidate the mechanism of anti-diabetes activity of Palo, especially focused on insulin resistance. Palo promoted adipocytes differentiation and regulated adipokine profiles in 3T3-L1 adipocytes by modulation of PPARγ, a major regulator of adipose differentiation. Human adipocyte showed almost similar profile with 3T3-L1 against Palo treatment. Furthermore, Palo treatment (250 or 1000 mg/kg) was performed with C57BL/6J mice for 14 weeks, being fed high-fat-diet (HFD60) simultaneously. Palo 250 mg/kg exhibited a tendency to decrease subcutaneous adipose volume along with increase of PPARγ and its target, adiponectin mRNA expression. In addition, as the other insulin targeted cell, effect on muscle differentiation was examined. Palo increased differentiation of C2C12 mouse muscle myoblasts by increase of IGF-1, myogenin, and myosine heavy chain (MHC) as well as 5'-AMP-activated protein kinase (AMPK) activation. Palo subsequently promoted myotube formation under differentiation condition. From the above, it was clarified that Palo acts variously on the differentiation and maturation of both adipocytes and muscle cells, and from the viewpoint of the regulatory mechanism for adipocytes, PPARγ-inducing action was shown to be a mechanism that acts across species.
  • Oishi N, Iwata H, Kambe N, Kobayashi N, Fujimoto K, Sato H, Hisaka A, Ueno K, Yamaura K
    Heliyon 5(6) e01981 2019年6月  査読有り
  • Miaki Uzu, Miki Nonaka, Kanako Miyano, Hiromi Sato, Nagomi Kurebayashi, Kazuyoshi Yanagihara, Takashi Sakurai, Akihiro Hisaka, Yasuhito Uezono
    Journal of pharmacological sciences 140(1) 109-112 2019年5月  査読有り
    Cancer cachexia is a systemic wasting syndrome characterized by anorexia and loss of body weight. The xanthine oxidase (XO) inhibitor febuxostat is one of the promising candidates for cancer cachexia treatment. However, cachexic symptoms were not alleviated by oral administration of febuxostat in our cancer cachexia model. Metabolomic analysis with brains of our cachexic model showed that purine metabolism was activated and XO activity was increased, and thus suggested that febuxostat would not reach the brain. Accordingly, targeting XO in the brain, which controls appetite, may be an effective strategy for treatment of cancer cachexia.
  • Sato H, Uzu M, Kashiba T, Fujiwara T, Hatakeyama H, Ueno K, Hisaka A
    European journal of pharmacology 847 143-157 2019年3月  査読有り筆頭著者責任著者
  • 宇津 美秋, 野中 美希, 宮野 加奈子, 佐藤 洋美, 上園 保仁
    日本癌学会総会記事 77回 1481-1481 2018年9月  
  • Yoshioka H, Sato H, Hatakeyama H, Hisaka A
    Blood advances 2(10) 1066-1075 2018年5月  査読有り
  • Miaki Uzu, Wun Chey Sin, Ayaka Shimizu, Hiromi Sato
    International Journal of Molecular Sciences 19(4) 2018年4月11日  査読有り責任著者
    The tumor microenvironment is known to have increased levels of cytokines and metabolites, such as glutamate, due to their release from the surrounding cells. A normal cell around the tumor that responds to the inflammatory environment is likely to be subsequently altered. We discuss how these abnormalities will support tumor survival via the actions of gap junctions (GJs) and hemichannels (HCs) which are composed of hexamer of connexin43 (Cx43) protein. In particular, we discuss how GJ intercellular communication (GJIC) in glioma cells, the primary brain tumor, is a regulatory factor and its attenuation leads to tumor invasion. In contrast, the astrocytes, which are normal cells around the glioma, are “hijacked” by tumor cells, either by receiving the transmission of malignant substances from the cancer cells via GJIC, or perhaps via astrocytic HC activity through the paracrine signaling which enable the delivery of these substances to the distal astrocytes. This astrocytic signaling would promote tumor expansion in the brain. In addition, brain metastasis from peripheral tissues has also been known to be facilitated by GJs formed between cerebral vascular endothelial cells and cancer cells. Astrocytes and microglia are generally thought to eliminate cancer cells at the blood–brain barrier. In contrast, some reports suggest they facilitate tumor progression as tumor cells take advantage of the normal functions of astrocytes that support the survival of the neurons by exchanging nutrients and metabolites. In summary, GJIC is essential for the normal physiological function of growth and allowing the diffusion of physiological substances. Therefore, whether GJIC is cancer promoting or suppressing may be dependent on what permeates through GJs, when it is active, and to which cells. The nature of GJs, which has been ambiguous in brain tumor progression, needs to be revisited and understood together with new findings on Cx proteins and HC activities.
  • Saki Kaneko, Chiaki Sato, Nobuya Shiozawa, Ayami Sato, Hiromi Sato, Nantiga Virgona, Tomohiro Yano
    Anticancer Research 38(3) 1391-1399 2018年3月1日  査読有り
    Background/Aim: A hallmark of the progression of prostate cancer to advanced disease is the acquisition of androgen-independent growth. This malignant phenotype is characterized by resistance to conventional treatments and predisposes to formation of hypoxic regions containing stem-like cancer cells. Unfortunately, an effective therapy to target prostate cancer stem cells under hypoxia has not yet been established. In this report, we studied whether δ-tocotrienol (T3), a vitamin E family member that has exhibited the most potent anti-cancer activity, could suppress the survival of prostate cancer stem-like cells. Materials and Μethods: PC3 stem-like cells were isolated from PC3 parental cells using a three-dimensional culture system. The stemness of the isolated PC3 stem-like cells was confirmed by evaluation of resistance to an anticancer agent (docetaxel) and tumor formation capacity in a xenograft model. The effects of δ-T3 on PC3 stem-like cells under a hypoxia condition were examined by WST-8 (cell viability), real-time reverse transcription-polymerase chain reaction (PCR) and western blotting. Results: δ-T3 demonstrated a cytotoxic effect on prostate cancer stem-like cells in a dose dependent manner and a reduction in the protein levels of hypoxia-inducible factor (HIF)-1α and HIF-2α. Additionally, a specific inhibitor toward HIF-1α induced cytotoxicity on PC3 cells, but selective inhibition of HIF-2α had no effect. Conclusion: Overall, these results suggest that δ-T3 could inhibit the survival of prostate cancer stem-like cells under hypoxia, primarily through the inactivation of HIF-1α signaling.
  • Hiroto Hatakeyama, Takuya Fujiwara, Hiromi Sato, Ayu Terui, Akihiro Hisaka
    Biological and Pharmaceutical Bulletin 41(4) 619-627 2018年  査読有り
    Acquired resistance to sunitinib is a challenge in the treatment of renal cell carcinoma (RCC). The dys-regulation of cellular metabolism is prevalent during resistance acquisition. It is known that in sunitinib-resistant RCC 786-O (786-O Res) cells sunitinib is mainly sequestered in the intracellular lysosomes. However, the relevance between sunitinib resistance and cellular metabolism has not been examined. In this study, we examined the metabolic changes in 786-O Res by using capillary electrophoresis-time of flight mass spectrometry. The cell line 786-O Res was established via persistent treatment with sunitinib, where increase in intracellular sunitinib, and sizes of lysosomes and nuclei were enhanced as compared with those in the parental 786-O (786-O Par) cells. Metabolic analyses revealed that out of the 110 metabolites examined, 13 were up-regulated and 4 were down-regulated in the 786-O Res cells. The glycolysis, tricarboxylic acid cycle and pentose phosphate pathway (PPP) were identified as being altered in the sunitinib-resistant cells, which resulted in the enhanced metabolisms of energy, nucleic acids, and glutathione redox cycle. As sunitinib was sequestered in the enlarged lysosomes in 786-O Res, the enriched energy metabolism might contribute to the maintenance of luminal pH in lysosomes via the H+ ATPase. The changes in the PPP could contribute to nuclei enlargement through up-regulation of nucleic acid biosynthesis and protect 786-O Res from cytotoxicity induced by sunitinib through up-regulation of reduced glutathione. Though the direct link between sunitinib resistance and metabolic alternation remains to be elucidated, this metabolomics study provides fundamental insights into acquisition of sunitinib resistance.
  • Till Ploenes, Mitja Fischer, Kerstin Hoehne, Hiromi Sato, Joachim Mueller-Quernheim, Gernot Zissel
    PATHOLOGY & ONCOLOGY RESEARCH 23(4) 723-730 2017年10月  査読有り
    Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that arises from the surface of the pleura and is associated with a history of asbestos exposure. The tumor is characterized by a strong local invasiveness and a poor response to any single modality therapy. Therefore clinical outcome of patients with MPM is poor and median survival time of untreated patients with MPM is 7 months from initial diagnosis. The Wilms Tumor Protein 1 (WT1) is a transcription factor which is highly expressed by MPM and is involved in cellular development and survival. We evaluated the role of WT1 in two human MPM cell lines (MSTO and H2052) expressing high levels of WT1. We performed a knockdown of WT1 using siRNA. Knockdown of WT1 was confirmed by Westernblotting. After knockdown of WT1 we investigated the effect on proliferation, chemoresistance, chemotaxis and migration. We could demonstrate that knockdown of WT1 suppresses chemoresistance in both cell lines compared with control (scrambled siRNA). Additionally, WT1 knockdown reduces proliferation, chemotaxis and invasiveness of mesothelioma cell lines. WT1 reduces malignancy of malignant mesothelioma cell lines and might be a new molecular target in mesothelioma therapy. Further investigations are needed to discover the mechanisms of chemoresistance depending on WT1.
  • Hirotaka Ando, Hiroto Hatakeyama, Hiromi Sato, Akihiro Hisaka, Hiroshi Suzuki
    JOURNAL OF PHARMACEUTICAL SCIENCES 106(9) 2771-2779 2017年9月  査読有り
    In this study, intestinal drug-drug interactions (DDIs) for substrate drugs of P-glycoprotein were simulated extensively using the extended Q(Gut) model and translocation model to explore the determinants of DDI. The results of analyses using both models suggested that permeability and active efflux clearance were the major factors that influenced the fraction absorbed (F-A). The results of simulation for 100 virtual drugs in which parameters were generated considering the actual values of commercially available drugs suggested that the ratio of the pH-corrected passive permeability to the intrinsic efflux clearance (Pu/CLeff) relative to that of digoxin would be a useful and quantitative index of P-glycoprotein (P-gp) emediated DDI risk at lower doses. At higher doses, such as 100 mg, the risk of P-gpe mediated DDI would be significantly reduced because of saturation of P-gp efflux. The simulation suggested that although drugs with lower permeability were more susceptible, even drugs with higher permeability than metoprolol, a representative highly permeable drug, such as BCS class 1 and 2, may experience DDIs owing to P-gp inhibition. Overall, this study demonstrated the usefulness of mathematical intestinal models when only limited observational data are available. (C) 2017 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved.
  • Hiromi Sato, Miaki Uzu, Tatsuro Kashiba, Rina Suzuki, Takuya Fujiwara, Hiroko Okuzawa, Koichi Ueno
    ONCOLOGY LETTERS 14(1) 937-943 2017年7月  査読有り筆頭著者責任著者
    Sunitinib (SU) is a small molecule that inhibits the receptor tyrosine kinase (RTK) signaling pathway, and has been clinically used to treat advanced renal cell carcinoma (RCC). However, SU is not always effective as RCC is a highly chemoresistant type of cancer. One of the factors that confer chemoresistance to RCC is a hypoxic condition. Lack of oxygen activates hypoxia-inducible factor (HIF) protein, which is followed by the upregulation of growth factors, including vascular endothelial growth factor and activation of the RTK signaling pathway. In this context, histone deacetylase inhibitors (HDACIs) are considered prominent combined agents for SU as they downregulate the expression of HIFs. Therefore, the present study aimed to investigate the effectiveness of combined treatment with SU and sodium butyrate (NaBu), an HDACI. Long-term exposure to these agents exerted a stronger growth inhibitory effect in RCC cell lines compared with single treatment groups. Furthermore, combined treatment suppressed HIF-2 alpha protein, which was induced under hypoxic conditions. In addition, this combination sustained the activity of the RTK signaling pathway to the level of intact cells, although a single treatment with SU or NaBu was demonstrated to increase this activity. Overall, it is suggested that the combination of SU and NaBu is effective for overcoming drug resistance in RCC.
  • Miaki Uzu, Hiromi Sato, Ayaka Shimizu, Yukihiro Shibata, Koichi Ueno, Akihiro Hisaka
    JOURNAL OF PHARMACOLOGICAL SCIENCES 134(2) 101-107 2017年6月  査読有り責任著者
    The constituent protein of gap junctions, connexin (Cx), interacts with various proteins via its C-terminus region, including kinases, cell-adhesion proteins, and a pro-apoptotic protein, Bax. This molecular interaction may affect expression and functioning of the interacting proteins and modulate the cellular physiology. In our previous work, Cx43 was found to interact directly with Bax and in the presence of sunitinib, lead to the Bax-mediated apoptosis in mesothelioma cells. In this study, we investigated the mechanism of how Cx43 promotes Bax-mediated apoptosis using the same cell line. Treatment with sunitinib increased the expression of the active conformation of the Bax protein, which was predominantly localized at the mitochondria, only in Cx43-transfected cells. Bax oligomerization and decrease in the mitochondrial membrane potential were also observed. The involvement of c-Jun N-terminal kinase (JNK) in the interaction of Cx43 and Bax was further examined. Treatment with sunitinib increased the expression of phosphorylated (active) form of JNK only in the Cx43-transfected cells. Phosphorylated JNK and active Bax were co-localized, and the co-localization was suppressed by the knockdown of Cx43. Moreover, JNK inhibition clearly suppressed Bax activation. In conclusion, we identified a novel Cx43-JNK-Bax axis regulating the process of apoptosis for the first time. (C) 2017 The Authors. Production and hosting by Elsevier B.V.
  • 上野光一, 佐藤洋美
    医学のあゆみ 260(12) 1066-1072 2017年  査読有り
  • Hiromi Sato, Asami Funaki, Yuki Kimura, Mai Sumitomo, Hiroya Yoshida, Hideki Fukata, Koichi Ueno
    NUTRITION RESEARCH 36(7) 731-741 2016年7月  査読有り筆頭著者責任著者
    In this study, we examined the cell differentiation effect of an ethanol extract of Cyclolepis genistoides D. Don, a herbaceous perennial belonging to the family Asteraceae (vernacular name: palo azul). Palo azul has numerous physiological effects that contribute to the prevention of metabolic syndromes, although the mechanism remains unclear. We previously suggested that palo azul has antidiabetic activity via an adipose differentiation effect. Here, we focused on whether palo azul promoted the differentiation of myoblasts. The mouse muscle myoblast cell line C2C12 was cultured and differentiated using horse serum with or without an ethanol extract of palo azul (12.5-200 mu g/ml). Quantitative realtime polymerase chain reaction was performed to evaluate differentiation markers, including insulin-like growth factor-1 and myogenin. To evaluate myotube formation, myosin heavy-chain (MHC) expression and localization were detected by immunohistochemistry. Palo azul increased the expression of the differentiation markers. Furthermore, immunohistochemistry analysis revealed increased formation of MHC myotubes after palo azul treatment along with increased diameter and fusion indices of the myotubes. The expression level of MHC was also increased. In conclusion, palo azul may increase muscle mass in the body and improve insulin resistance conditions by facilitating the formation of myotubes by promoting myocyte differentiation. (C) 2016 Elsevier Inc. All rights reserved.
  • Hiromi Sato, Yuki Kurauchi
    YAKUGAKU ZASSHI-JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN 136(5) 685-686 2016年5月  査読有り責任著者
  • 佐藤洋美, 倉内祐樹, 大澤匡弘, 村上友康, 粂和彦, 籠田智美, 岩田紗季, 丸山加菜, 和久田浩一, 篠塚和正, 葛巻直子, 成田道子, 池上大悟, 成田年, 黒田正幸, 武城英明, 麻生雅是, 齋藤康, 横手幸太郎, 友田明美
    薬学雑誌 136 685-714 2016年  査読有り責任著者
  • Miaki Uzu, Hiromi Sato, Ryota Yamada, Tatsuro Kashiba, Yukihiro Shibata, Katsunori Yamaura, Koichi Ueno
    JOURNAL OF PHARMACOLOGICAL SCIENCES 128(1) 17-26 2015年5月  査読有り責任著者
    Connexin (Cx) makes up a type of intercellular channel called gap junction (GJ). GJ plays a regulatory role in cellular physiology. The Cx expression level is often decreased in cancer cells compared to that in healthy ones, and the restoration of its expression has been shown to exert antiproliferative effects. This work aims to evaluate the effect of the restoration of connexin 43 (Cx43) (the most ubiquitous Cx subtype) expression on sunitinib (SU)-induced cytotoxicity in malignant mesothelioma (MM) cells. Increased Cx43 expression in an MM cell line (H28) improved the ability of SU to inhibit receptor tyrosine kinase (RTK) signaling. Moreover, higher Cx43 expression promoted SU-induced apoptosis. The cell viability test revealed that Cx43 enhanced the cytotoxic effect of SU in a GJ-independent manner. The effect of Cx43 on a proapoptotic factor, Bax, was then investigated. The interaction between Cx43 and Bax was confirmed by immunoprecipitation. Furthermore, higher Cx43 expression increased the production of a cleaved (active) form of Bax during SU-induced apoptosis with no alteration in total Bax expression. These findings indicate that Cx43 most likely increases sensitivity to SU in H28 through direct interaction with Bax. In conclusion, we found that Cx43 overcame the chemoresistance of MM cells. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of Japanese Pharmacological Society.
  • Katsunori Yamaura, Riho Tanaka, Yuanyuan Bi, Hideki Fukata, Nobuo Oishi, Hiromi Sato, Chisato Mori, Koichi Ueno
    PHARMACOGNOSY MAGAZINE 11(42) S86-S92 2015年5月  査読有り
    Background: Many health experts support the hypothesis that stressful lifestyles are the leading cause of illness, like depression. Therefore, from the standpoint of preventive medicine, it is important to reduce stress. Young green barley leaves are a good natural source of vitamins and minerals, and their juice is widely consumed as a functional food for health reasons in Japan. This study investigated the protective effect of young green barley leaves for stress control. Materials and Methods: ICR outbred mice were exposed to 3-h sessions of restraint stress. Young green barley leaves (400 and 1,000 mg/kg) were administered orally 1 h before the sessions for 5 days. To analyze voluntary behavior, wheel-running activity was monitored during the dark period. Brain-derived neurotrophic factor (BDNF) messenger RNA (mRNA) expression in the whole hippocampus was measured by real-time quantitative polymerase chain reaction. Results: Restraint stress resulted in a significant decrease in voluntary wheel-running behavior, but this decrease was ameliorated by the administration of young green barley leaves. The leaves also enhanced the decreased levels of BDNF mRNA induced by restraint stress; in particular, a significant protective effect was shown in the exon IV variant as compared to vehicle control mice. Conclusion: The findings suggest that young green barley leaves have potent anti-stress properties, as evidenced by preventing decreases in the levels of voluntary wheel-running activity and hippocampal BDNF mRNA in response to restraint stress. Our findings support the possibility that supplementation with young green barley leaves might be beneficial for preventing stress-related psychiatric disorders like depression.
  • Sato H, Uzu M
    Nihon yakurigaku zasshi. Folia pharmacologica Japonica 145(2) 74-79 2015年2月  査読有り責任著者
  • Hiromi Sato, Sana Siddig, Miaki Uzu, Sayumi Suzuki, Yuki Nomura, Tatsuro Kashiba, Keisuke Gushimiyagi, Yuko Sekine, Tomoya Uehara, Yasushi Arano, Katsunori Yamaura, Koichi Ueno
    EUROPEAN JOURNAL OF PHARMACOLOGY 746 258-266 2015年1月  査読有り筆頭著者責任著者
    intrinsic drug resistance occurs in many renal carcinomas and is associated with increased expression of multidrug resistant proteins, which inhibits intracellular drug accumulation. Multidrug resistant protein 1, also known as P-glycoprotein, is a membrane drug efflux pump belonging to the ATP-binding cassette (ABC) transporter superfamily. ABC Sub-family B Member 2 (ABCG2) is widely distributed and is involved in the multidrug resistant phenotype. Sunitinib is a tyrosine kinase inhibitor used to treat kidney cancer that disrupts signaling pathways responsible for abnormal cancer cell proliferation and tumor angiogenesis. Multiple drug resistance is important in tyrosine kinase inhibitor-induced resistance. We hypothesized that inhibition of multiclrug resistant transporters by elacridar (dual inhibitor of P-glycoprotein and ABCG 2) might overcome sunitinib resistance in experimental renal cell carcinoma. Human renal carcinoma cell lines 786-O, ACHN, and Caki-1 were treated with sunitinib or elacriclar alone, or in combination. We showed that elacridar significantly enhanced sunitinib cytotoxicity in 786-O cells. P-glycoprotein activity, confirmed by P-glycoprotein function assay, was found to be inhibited by elacridar. ABCG2 expression was low in all renal carcinoma cell lines, and was suppressed only by combination treatment in 786-O cells. ABCG2 function was inhibited by sunitinib alone or combination with elacridar but not elacridar alone. These findings suggest that sunitinib resistance involves multidrug resistance transporters, and in combination with elacridar, can be reversed in renal carcinoma cells by P-glycoprotein inhibition. (C) 2014 Elsevier B.V. All rights reserved.
  • 佐藤洋美, 宇津美秋
    日本薬理学雑誌 145 74-79 2015年  査読有り責任著者
  • 佐藤洋美, 上野光一
    日本臨牀 73(4) 542-546 2015年  査読有り
  • Sato H, Ishikawa M, Sugai H, Funaki A, Kimura Y, Sumitomo M, Ueno K
    Hormone molecular biology and clinical investigation 20(2) 51-61 2014年11月1日  査読有り筆頭著者責任著者
  • Takao Namiki, Hiromi Sato, Yukari Matsumoto, Haruka Kakikura, Koichi Ueno, Atsushi Chino, Hideki Okamoto, Akito Hisanaga, Akiyo Kaneko, Toshiaki Kita, Maki Kihara, Makio Shozu, Katsutoshi Terasawa
    EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014 962109 2014年  査読有り
    Keishibukuryogan (KBG; Guizhi-Fuling-Wan in Chinese) is one of the Kampo (Japanese traditional) medicines used to treat patients with climacteric syndrome. KBG can be used by patients who cannot undergo hormone replacement therapy due to a history of breast cancer. We evaluated whether cytosine-adenine (CA) repeat polymorphism of the estrogen receptor.. gene can be a predictor of the beneficial effect of KBG on climacteric syndrome. We also investigated the relationship between CA repeat polymorphism, the patients' profiles, and the therapeutic effect. We found that CA was an SS, SL, or LL genotype according to the number of repeats. We studied 39 consecutive patients with climacteric disorders who took KBG for 12 weeks. The diagnosis of climacteric disorders was made on the basis of the Kupperman index. KBG significantly improved the patients' climacteric symptoms (i.e., vasomotor symptoms in the patients with the LL genotype and melancholia in the patients with the SL genotype). No relationship between the patients' profiles and CA repeat polymorphism was recognized. CA repeat polymorphism could thus be a potential biomarker to predict the efficacy of KBG in climacteric syndrome, and its use will help to reduce the cost of treating this syndrome by focusing the administration of KBG on those most likely to benefit from it.
  • 上野光一, 佐藤洋美
    月刊薬事 56(2) 239-242 2014年  査読有り
  • 島田万里江, 佐藤洋美, 関根祐子, 上野光一
    医薬品医療機器レギュラトリーサイエンス 45(2) 147-154 2014年  査読有り責任著者
  • Hiromi Sato, Momoko Ishikawa, Asami Funaki, Yuki Kimura, Hiroya Yoshida, Hideki Fukata, Hideo Hasegawa, Koichi Ueno
    Nutrition Research 33(11) 922-931 2013年11月  査読有り筆頭著者責任著者
    Cyclolepis genistoides D. Don is a herbaceous perennial belonging to the family Asteraceae, and its vernacular name is "palo azul" (palo). Palo has been reported to exhibit many physiological effects that contribute to the prevention of metabolic syndromes, although its mechanism is unclear. Among palo's various activities, we investigated the hypothesis that palo promotes adipocytes differentiation and regulates adipokine profiles in 3T3-L1 adipocytes by modulation of peroxisome proliferator-activated receptor (PPAR) γ, a major regulator of adipose differentiation. 3T3-L1 adipocytes were cultured and differentiated in Dulbecco modified Eagle medium with 50 to 200 μg/mL palo for 7 days or were cultured with palo without differentiation protocol for 14 days. Palo down-regulated the expression of 2 types of expressed/secreted adipokines, leptin and resistin, in a concentration-dependent manner. Under a nondifferentiated condition, palo promoted the accumulation of lipid droplets in cells. Real-time polymerase chain reaction and luciferase reporter assay showed that palo up-regulated expression and transcriptional activity of PPAR. γ. Furthermore, palo increased the expression of insulin-sensitizing adipokine, adiponectin, which is a directly target of PPAR. γ, both at the messenger RNA level and at the protein level. In summary, palo demonstrated the potential to improve insulin resistance by promoting adipocyte differentiation via PPAR. γ activation. Results suggest an increase in adiponectin secretion and a decrease in insulin-resistant factors such as leptin and resistin. © 2013 Elsevier Inc.
  • Guligena Tuerdi, Saki Ichinomiya, Hiromi Sato, Sana Siddig, Eriko Suwa, Hiroki Iwata, Tomohiro Yano, Koichi Ueno
    CANCER LETTERS 339(1) 116-127 2013年10月  査読有り責任著者
    The present study is the first to demonstrate the synergetic effect of statins (atorvastatin and simvastatin) and gamma-tocotrienol (gamma-T3) on human malignant mesothelioma (MM). Statin + gamma-T3 combinations induced greater cell growth inhibition more than each single treatment via inhibition of mevalonate pathway, a well-known target of both gamma-T3 and statins. gamma-T3 was necessary for endoplasmic reticulum stress markers CHOP and GRP78, whereas an intrinsic apoptotic marker, caspase 3 activation was induced only in the presence of statins. Overall, the combination of gamma-T3 and statins could be useful for MM therapy and functions in a complementary style. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
  • Ryouya Nomura, Madoka Yanagihara, Hiromi Sato, Kenjiro Matsumoto, Kimihito Tashima, Shunji Horie, Shuonan Chen, Hiromichi Fujino, Kouichi Ueno, Toshihiko Murayama
    EUROPEAN JOURNAL OF PHARMACOLOGY 718(1-3) 314-322 2013年10月  査読有り
    Various events including digestion and inflammation are regulated by secreted phospholipase A(2) (sPLA(2)) in gastrointestinal tissues, however, the role of sPLA(2) on contractile activity has not been elucidated. We investigated the effect of bee venom PLA(2) (bvPLA(2)), which is homologous to the central domain of group Ill sPLA(2), on contractile activity in mouse rectum. The longitudinal preparations of rectum showed rhythmic phasic contractions (RPCs) with varied amplitude ancl high frequency. Treatment with bvPLA(2) at 1 mu g/ml increased amplitudes of RPCs without markecl changes in frequency and basal tone. RPCs by bvPLA(2) were affected neither by atropine nor by inhibition of nitric oxide synthase, and partly inhibited by dual inhibition of the cyclooxygenase and lipoxygenase pathways. Pretreatment of bvPLA(2) with dithiothreitol, which inhibits the enzyme activity, partly reduced bvPLA(2)-induced RPCs, and arachiclonic acid-increased RPCs were completely abolished by cyclooxygenase/lipoxygenase inhibition. Phasic contractions have been shown to be regulated by gap junction and to be decreased in gastrointestinal tissues with experimental colitis. Treatment with inhibitors of gap junction proteins, 50 mu M 14-glycyrrhetinic acid and 100 mu M carbenoxolone, partly and almost completely reduced bvPLA(2)-induced RPCs without and with the cyclooxygenase/lipoxygenase inhibitors, respectively, but not arachidonic acid induced RPCs. In rectum from mouse having colitis, where total levels and modified forms of connexin43 increased, bvPLA(2)-induced RPCs were markedly decreased. Our results suggest that both arachidonic acid metabolism and gap junction proteins independently regulated the 5PLA(2)-induced RPCs in mouse rectum. An increased expression and/or modification of connexin43 may influence 5PLA(2)-induced RPCs iii rectum with colitis. (C) 2013 Elsevier B.V. All rights reserved
  • Hiromi Sato, Hana Sugai, Hiroshi Kurosaki, Momoko Ishikawa, Asami Funaki, Yuki Kimura, Koichi Ueno
    BIOLOGICAL & PHARMACEUTICAL BULLETIN 36(4) 564-573 2013年4月  査読有り筆頭著者責任著者
    Peroxisome proliferator-activated receptor (PPAR) gamma plays a major role in the regulation of lipid and carbohydrate metabolism. Pioglitazone is a PPAR gamma agonist that is widely used for the treatment of type 2 diabetes mellitus. However, female patients have been reported to experience stronger efficacy and adverse effects than male patients. This study evaluated the effects of sex hormones on PPAR gamma expression and activity in adipocytes. Mouse 3T3-L1 preadipocytes were used after being grown into matured adipocytes. The sex hormones 17/beta-estradiol (E2), testosterone (T), or 5 alpha-androstan-17 beta-ol-3-one (dihydrotestosterone; DHT) were added to the matured adipocytes and the cells were then maintained for short (24-72 h) or long (1- or 2-weeks) periods. E2 significantly upregulated PPAR gamma protein expression in a concentration-dependent manner after extended exposure, whereas T and DHT did not have such an effect. When cells were co-treated with pioglitazone and E2, PPAR gamma protein expression significantly increased in an E2-dependent manner, whereas this expression seemed to be reduced by pioglitazone mono-treatment and co-treatment with DHT at higher concentrations. The secretion levels of adiponectin protein, a major indicator of PPAR gamma activity, were significantly decreased by DHT, but were not affected by E2. Finally a luciferase assay was performed using a PPAR response element-Luk reporter gene. Transcriptional activity was not changed by any of single sex hormone treatment, but was significantly downregulated by co-treatment with pioglitazone and DHT. Taken together, our results suggest that sex hormones may influence PPAR gamma expression and function, which may explain the observed sex-specific different effect of pioglitazone.

MISC

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書籍等出版物

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講演・口頭発表等

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担当経験のある科目(授業)

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共同研究・競争的資金等の研究課題

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社会貢献活動

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