研究者業績

北本 匠

キタモト タクミ  (Takumi Kitamoto)

基本情報

所属
千葉大学 千葉大学医学部附属病院 助教 (診療講師)
学位
医学士(2008年3月 千葉大学医学部)
医学博士(2017年3月 千葉大学大学院医学薬学府)

連絡先
t.kitamotochiba-u.jp
研究者番号
90916173
ORCID ID
 https://orcid.org/0000-0002-9457-267X
J-GLOBAL ID
202101007450993555
researchmap会員ID
R000028887

研究キーワード

 1

学歴

 3

受賞

 7

論文

 44
  • Hajime Kato, Takumi Kitamoto, Soichiro Kimura, Takashi Sunouchi, Yoshitomo Hoshino, Naoko Hidaka, Yuya Tsurutani, Nobuaki Ito, Noriko Makita, Tetsuo Nishikawa, Masaomi Nangaku, Kosuke Inoue
    Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists 2024年4月22日  
    BACKGROUND: While clinical features of KCNJ5-mutated aldosterone-producing adenoma (APA) have been reported, evidence of its clinical outcomes is lacking. We aimed to synthesize available literature about the associations between KCNJ5 mutation with cardiovascular and metabolic outcomes among patients with APA. METHODS: In this systematic review of observational studies, MEDLINE and EMBASE were searched through August 2022. Two independent authors screened the search results and extracted data from eligible observational studies investigating cardiovascular or metabolic outcomes between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs. Risk of Bias In Non-randomized Studies of Interventions was used to assess the quality of the included studies. RESULTS: A total of 573 titles/abstracts were screened and after the expert opinion of the literature, 20 were read the full text, of which 12 studies were included. Across three studies comparing the baseline or change in the cardiac function between KCNJ5-mutated APAs and KCNJ5-non-mutated APAs, all studies reported the association between impaired cardiac functions and KCNJ5 mutation status. Among six studies evaluating the cure of hypertension after surgery, all studies showed that KCNJ5 mutation was significantly associated with the cure of hypertension. In quality assessment, seven studies were at serious risk of bias, while the remaining studies were at moderate risk of bias. CONCLUSIONS: This systematic review provided evidence of the significant association between KCNJ5 mutation and unfavorable cardiovascular outcomes in patients with primary aldosteronism. Further research is needed to improve the quality of evidence on this topic and elucidate the underlying mechanisms of the potential burden of KCNJ5 mutation.
  • Domenico Accili, Shivatra C Talchai, Ryotaro Bouchi, April Yun-Kyoung Lee, Wen Du, Takumi Kitamoto, Wendy M McKimpson, Sandro Belvedere, Hua V Lin
    Journal of diabetes investigation 2024年3月1日  
    Insulin-deficient (type 1) diabetes is treated by providing insulin to maintain euglycemia. The current standard of care is a quasi-closed loop integrating automated insulin delivery with a continuous glucose monitoring sensor. Cell replacement technologies are advancing as an alternative treatment and have been tested as surrogates to cadaveric islets in transplants. In addition, immunomodulatory treatments to delay the onset of type 1 diabetes in high-risk (stage 2) individuals have gained regulatory approval. We have pioneered a cell conversion approach to restore insulin production through pharmacological conversion of intestinal epithelial cells into insulin-producing cells. We have advanced this approach along a translational trajectory through the discovery of small molecule forkhead box protein O1 inhibitors. When administered to different rodent models of insulin-deficient diabetes, these inhibitors have resulted in robust glucose-lowering responses and generation of insulin-producing cells in the gut epithelium. We review past work and delineate a path to human clinical trials.
  • 矢野 愛美香, 菅生 将史, 野牛 勇佑, 渡邉 涼香, 五十嵐 活志, 類家 裕太郎, 石渡 一樹, 藤本 真徳, 北本 匠, 鈴木 佐和子, 小出 尚史, 市川 智彦, 横手 幸太郎
    日本内分泌学会雑誌 99(4) 892-892 2024年1月  
  • Takumi Kitamoto, Tsuyoshi Idé, Yuta Tezuka, Norio Wada, Yui Shibayama, Yuya Tsurutani, Tomoko Takiguchi, Kosuke Inoue, Sachiko Suematsu, Kei Omata, Yoshikiyo Ono, Ryo Morimoto, Yuto Yamazaki, Jun Saito, Hironobu Sasano, Fumitoshi Satoh, Tetsuo Nishikawa
    Scientific reports 13(1) 21722-21722 2023年12月11日  査読有り筆頭著者責任著者
    Adrenal venous sampling (AVS) is crucial for subtyping primary aldosteronism (PA) to explore the possibility of curing hypertension. Because AVS availability is limited, efforts have been made to develop strategies to bypass it. However, it has so far proven unsuccessful in applying clinical practice, partly due to heterogeneity and missing values of the cohorts. For this purpose, we retrospectively assessed 210 PA cases from three institutions where segment-selective AVS, which is more accurate and sensitive for detecting PA cases with surgical indications, was available. A machine learning-based classification model featuring a new cross-center domain adaptation capability was developed. The model identified 102 patients with PA who benefited from surgery in the present cohort. A new data imputation technique was used to address cross-center heterogeneity, making a common prediction model applicable across multiple cohorts. Logistic regression demonstrated higher accuracy than Random Forest and Deep Learning [(0.89, 0.86) vs. (0.84, 0.84), (0.82, 0.84) for surgical or medical indications in terms of f-score]. A derived integrated flowchart revealed that 35.2% of PA cases required AVS with 94.1% accuracy. The present model enabled us to reduce the burden of AVS on patients who would benefit the most.
  • Hiyori Kaneko, Yoshiro Maezawa, Ayano Tsukagoshi-Yamaguchi, Masaya Koshizaka, Aki Takada-Watanabe, Rito Nakamura, Shinichiro Funayama, Kazuto Aono, Naoya Teramoto, Daisuke Sawada, Yukari Maeda, Takuya Minamizuka, Aiko Hayashi, Kana Ide, Shintaro Ide, Mayumi Shoji, Takumi Kitamoto, Minoru Takemoto, Hisaya Kato, Koutaro Yokote
    Geriatrics & gerontology international 2023年12月8日  査読有り
    AIM: Whether sex differences exist in hereditary progeroid syndromes remains unclear. In this study, we investigated sex differences in patients with Werner syndrome (WS), a model of human aging, using patient data at the time of diagnosis. METHODS: The presence of six cardinal signs in the diagnostic criteria was retrospectively evaluated. RESULTS: We found that the percentage of patients with all cardinal signs was higher in males than in females (54.2% vs. 21.2%). By the age of 40 years, 57.1% of male patients with WS presented with all the cardinal signs, whereas none of the female patients developed all of them. In particular, the frequency of having a high-pitched, hoarse voice, a characteristic of WS, was lower in female patients. The positive and negative predictive values for clinical diagnosis were 100% for males and females, indicating the helpfulness of diagnostic criteria regardless of sex. More female patients than male (86.7% vs. 64%) required genetic testing for their diagnosis because their clinical symptoms were insufficient, suggesting the importance of genetic testing for females even if they do not show typical symptoms of WS. Finally, the frequency of abnormal voice was lower in patients with WS harboring the c.3139-1G > C homozygous mutation. CONCLUSION: These results indicate, for the first time, that there are sex differences in the phenotypes of hereditary progeroid syndromes. The analysis of this mechanism in this human model of aging may lead to the elucidation of sex differences in the various symptoms of normal human aging. Geriatr Gerontol Int 2023; ••: ••-••.
  • Daisuke Sawada, Hisaya Kato, Hiyori Kaneko, Daisuke Kinoshita, Shinichiro Funayama, Takuya Minamizuka, Atsushi Takasaki, Katsushi Igarashi, Masaya Koshizaka, Aki Takada-Watanabe, Rito Nakamura, Kazuto Aono, Ayano Yamaguchi, Naoya Teramoto, Yukari Maeda, Tomohiro Ohno, Aiko Hayashi, Kana Ide, Shintaro Ide, Mayumi Shoji, Takumi Kitamoto, Yusuke Endo, Hideyuki Ogata, Yoshitaka Kubota, Nobuyuki Mitsukawa, Atsushi Iwama, Yasuo Ouchi, Naoya Takayama, Koji Eto, Katsunori Fujii, Tomozumi Takatani, Tadashi Shiohama, Hiromichi Hamada, Yoshiro Maezawa, Koutaro Yokote
    Aging 15(19) 9948-9964 2023年10月3日  査読有り
    Werner syndrome (WS) is a hereditary premature aging disorder characterized by visceral fat accumulation and subcutaneous lipoatrophy, resulting in severe insulin resistance. However, its underlying mechanism remains unclear. In this study, we show that senescence-associated inflammation and suppressed adipogenesis play a role in subcutaneous adipose tissue reduction and dysfunction in WS. Clinical data from four Japanese patients with WS revealed significant associations between the decrease of areas of subcutaneous fat and increased insulin resistance measured by the glucose clamp. Adipose-derived stem cells from the stromal vascular fraction derived from WS subcutaneous adipose tissues (WSVF) showed early replicative senescence and a significant increase in the expression of senescence-associated secretory phenotype (SASP) markers. Additionally, adipogenesis and insulin signaling were suppressed in WSVF, and the expression of adipogenesis suppressor genes and SASP-related genes was increased. Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR), alleviated premature cellular senescence, rescued the decrease in insulin signaling, and extended the lifespan of WS model of C. elegans. To the best of our knowledge, this study is the first to reveal the critical role of cellular senescence in subcutaneous lipoatrophy and severe insulin resistance in WS, highlighting the therapeutic potential of rapamycin for this disease.
  • Takumi Kitamoto, Domenico Accili
    Endocrine journal 70(9) 851-866 2023年9月28日  査読有り招待有り筆頭著者責任著者
    Over 100 years have passed since insulin was first administered to a diabetic patient. Since then great strides have been made in diabetes research. It has determined where insulin is secreted from, which organs it acts on, how it is transferred into the cell and is delivered to the nucleus, how it orchestrates the expression pattern of the genes, and how it works with each organ to maintain systemic metabolism. Any breakdown in this system leads to diabetes. Thanks to the numerous researchers who have dedicated their lives to cure diabetes, we now know that there are three major organs where insulin acts to maintain glucose/lipid metabolism: the liver, muscles, and fat. The failure of insulin action on these organs, such as insulin resistance, result in hyperglycemia and/or dyslipidemia. The primary trigger of this condition and its association among these tissues still remain to be uncovered. Among the major organs, the liver finely tunes the glucose/lipid metabolism to maintain metabolic flexibility, and plays a crucial role in glucose/lipid abnormality due to insulin resistance. Insulin resistance disrupts this tuning, and selective insulin resistance arises. The glucose metabolism loses its sensitivity to insulin, while the lipid metabolism maintains it. The clarification of its mechanism is warranted to reverse the metabolic abnormalities due to insulin resistance. This review will provide a brief historical review for the progress of the pathophysiology of diabetes since the discovery of insulin, followed by a review of the current research clarifying our understanding of selective insulin resistance.
  • 寺本 直弥, 前澤 善朗, 山口 彩乃, 金子 ひより, 南塚 拓也, 加藤 尚也, 井出 真太郎, 井出 佳奈, 北本 匠, 越坂 理也, 遠藤 裕介, 秋元 義弘, 横手 幸太郎
    糖尿病合併症 37(Suppl.1) 171-171 2023年9月  
  • Yusuke Goto, Takumi Kitamoto, Satoki Tanaka, Masafumi Maruo, Sho Sugawara, Kazuto Chiba, Kanetaka Miyazaki, Atsushi Inoue, Kazuki Nakai, Yuya Tsurutani, Jun Saito, Masao Omura, Tetsuo Nishikawa, Tomohiko Ichikawa, Maki Nagata
    Surgery 174(2) 234-240 2023年5月13日  査読有り
    BACKGROUND: The surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy for patients with aldosterone-producing adenomas are unknown. Precise diagnosis of intra-adrenal aldosterone activity and a precise surgical procedure may improve outcomes. In this study, we aimed to determine the surgical and endocrinological outcomes of single-port laparoscopic partial adrenalectomy with preoperative segmental selective adrenal venous sampling and intraoperative high-resolution laparoscopic ultrasound in patients with unilateral aldosterone-producing adenomas. We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. METHODS: A single-center, retrospective cohort study. All patients with unilateral aldosterone-producing adenomas diagnosed by selective adrenal venous sampling and treated surgically between January 2012 and February 2015 were included. Follow-up with biochemical and clinical assessments was set at 1 year after surgery for short-term outcomes and was performed every 3 months after surgery. RESULTS: We identified 53 patients with partial adrenalectomy and 29 patients with laparoscopic total adrenalectomy. Single-port surgery was performed for 37 and 19 patients, respectively. Single-port surgery was associated with shorter operative and laparoscopic times (odds ratio, 0.14; 95% confidence interval, 0.039-0.49; P = .002 and odds ratio, 0.13; 95% confidence interval, 0.032-0.57; P = .006, respectively). All single-port and multi-port partial adrenalectomy cases showed complete short-term (median 1 year) biochemical success, and 92.9% (26 of 28 patients) who underwent single-port partial adrenalectomy and 100% (13 of 13 patients) who underwent multi-port partial adrenalectomy showed complete long-term (median 5.5 years) biochemical success. No complications were observed with single-port adrenalectomy. CONCLUSION: Single-port partial adrenalectomy is feasible after selective adrenal venous sampling for unilateral aldosterone-producing adenomas, with shorter operative and laparoscopic times and a high rate of complete biochemical success.
  • Wendy M McKimpson, Sophia Spiegel, Maria Mukhanova, Michael Kraakman, Wen Du, Takumi Kitamoto, Junjie Yu, Utpal Pajvani, Domenico Accili
    bioRxiv : the preprint server for biology 2023年3月7日  
    Calorie restriction increases lifespan. While some tissue-specific protective effects of calorie restriction have been described, the impact of calorie restriction on the gastrointestinal tract remains unclear. We found increased abundance of chromogranin A+, including orexigenic ghrelin+, endocrine cells in the stomach of calorie-restricted mice. This effect coincided with increased Notch target Hes1 and Notch ligand Jag1 and was reversed when Notch signaling was blocked using the γ-secretase inhibitor DAPT. Using primary cultures and genetically-modified reporter mice, we determined that increased endocrine cell abundance was due to altered stem and progenitor proliferation. Different from the intestine, calorie restriction decreased gastric Lgr5+ stem cells, while increasing a FOXO1/Neurog3+ subpopulation of endocrine progenitors in a Notch-dependent manner. Further, calorie restriction triggered nuclear localization of FOXO1, which was sufficient to promote endocrine cell differentiation. Taken together, the data indicate that calorie restriction promotes gastric endocrine cell differentiation triggered by active Notch signaling and regulated by FOXO1.
  • Hitoshi Watanabe, Wen Du, Jinsook Son, Lina Sui, Shun-Ichiro Asahara, Irwin J Kurland, Taiyi Kuo, Takumi Kitamoto, Yasutaka Miyachi, Rafael de Cabo, Domenico Accili
    Science translational medicine 15(681) eabq4126 2023年2月  査読有り
    Sulfonylureas (SUs) are effective and affordable antidiabetic drugs. However, chronic use leads to secondary failure, limiting their utilization. Here, we identify cytochrome b5 reductase 3 (Cyb5r3) down-regulation as a mechanism of secondary SU failure and successfully reverse it. Chronic exposure to SU lowered Cyb5r3 abundance and reduced islet glucose utilization in mice in vivo and in ex vivo murine islets. Cyb5r3 β cell-specific knockout mice phenocopied SU failure. Cyb5r3 engaged in a glucose-dependent interaction that stabilizes glucokinase (Gck) to maintain glucose utilization. Hence, Gck activators can circumvent Cyb5r3-dependent SU failure. A Cyb5r3 activator rescued secondary SU failure in mice in vivo and restored insulin secretion in ex vivo human islets. We conclude that Cyb5r3 is a key factor in the secondary failure to SU and a potential target for its prevention, which might rehabilitate SU use in diabetes.
  • Domenico Accili, Wen Du, Takumi Kitamoto, Taiyi Kuo, Wendy McKimpson, Yasutaka Miyachi, Maria Mukhanova, Jinsook Son, Liheng Wang, Hitoshi Watanabe
    Diabetology international 14(1) 21-31 2023年1月  査読有り招待有り
    Research on the etiology and treatment of diabetes has made substantial progress. As a result, several new classes of anti-diabetic drugs have been introduced in clinical practice. Nonetheless, the number of patients achieving glycemic control targets has not increased for the past 20 years. Two areas of unmet medical need are the restoration of insulin sensitivity and the reversal of pancreatic beta cell failure. In this review, we integrate research advances in transcriptional regulation of insulin action and pathophysiology of beta cell dedifferentiation with their potential impact on prospects of a durable "cure" for patients suffering from type 2 diabetes.
  • Yun-Kyoung Lee, Wen Du, Yaohui Nie, Bryan Diaz, Nishat Sultana, Takumi Kitamoto, Rudolph L Leibel, Domenico Accili, Sandro Belvedere
    Molecular metabolism 66 101618-101618 2022年12月  査読有り
    OBJECTIVES: Insulin treatment remains the sole effective intervention for Type 1 Diabetes. Here, we investigated the therapeutic potential of converting intestinal epithelial cells to insulin-producing, glucose-responsive β-like cells by targeted inhibition of FOXO1. We have previously shown that this can be achieved by genetic ablation in gut Neurogenin3 progenitors, adenoviral or shRNA-mediated inhibition in human gut organoids, and chemical inhibition in Akita mice, a model of insulin-deficient diabetes. METHODS: We profiled two novel FOXO1 inhibitors in reporter gene assays, and hepatocyte gene expression studies, and in vivo pyruvate tolerance test (PTT) for their activity and specificity. We evaluated their glucose-lowering effect in mice rendered insulin-deficient by administration of streptozotocin. RESULTS: We provide evidence that two novel FOXO1 inhibitors, FBT432 and FBT374 have glucose-lowering and gut β-like cell-inducing properties in mice. FBT432 is also highly effective in combination with a Notch inhibitor in this model. CONCLUSION: The data add to a growing body of evidence suggesting that FOXO1 inhibition be pursued as an alternative treatment to insulin administration in diabetes.
  • Wen Du, Junqiang Wang, Taiyi Kuo, Liheng Wang, Wendy M. McKimpson, Jinsook Son, Hitoshi Watanabe, Takumi Kitamoto, Yun-Kyoung Lee, Remi J. Creusot, Lloyd E. Ratner, Kasi McCune, Ya-Wen Chen, Brendan H. Grubbs, Matthew E. Thornton, Jason Fan, Nishat Sultana, Bryan S. Diaz, Iyshwarya Balasubramanian, Nan Gao, Sandro Belvedere, Domenico Accili
    Journal of Clinical Investigation 132(24) 2022年10月25日  査読有り
    As a highly regenerative organ, the intestine is a promising source for cellular reprogramming for replacing lost pancreatic β cells in diabetes. Gut enterochromaffin cells can be converted to insulin-producing cells by forkhead box O1 (FoxO1) ablation, but their numbers are limited. In this study, we report that insulin-immunoreactive cells with Paneth/goblet cell features are present in human fetal intestine. Accordingly, lineage-tracing experiments show that, upon genetic or pharmacologic FoxO1 ablation, the Paneth/goblet lineage can also undergo conversion to the insulin lineage. We designed a screening platform in gut organoids to accurately quantitate β-like cell reprogramming and fine-tune a combination treatment to increase the efficiency of the conversion process in mice and human adult intestinal organoids. We identified a triple blockade of FOXO1, Notch, and TGF-β that, when tested in insulin-deficient streptozotocin (STZ) or NOD diabetic animals, resulted in near normalization of glucose levels, associated with the generation of intestinal insulin-producing cells. The findings illustrate a therapeutic approach for replacing insulin treatment in diabetes.
  • Takumi Kitamoto, Yun-Kyoung Lee, Nishat Sultana, Hitoshi Watanabe, Wendy M. M, Kimpson, Wen Du, Jason Fan, Bryan Diaz, Hua V. Lin, Rudolph L. Leibel, Sandro Belvedere, Domenico Accili
    Molecular Metabolism 66 101624-101624 2022年10月  査読有り筆頭著者責任著者
    OBJECTIVE: Lifelong insulin replacement remains the mainstay of type 1 diabetes treatment. Genetic FoxO1 ablation promotes enteroendocrine cell (EECs) conversion into glucose-responsive β-like cells. Here, we tested whether chemical FoxO1 inhibitors can generate β-like gut cells. METHODS: We used Ngn3-or Villin-driven FoxO1 ablation to capture the distinctive developmental effects of FoxO1 on EEC pool. We combined FoxO1 ablation with Notch inhibition to enhance the expansion of EEC pool. We tested the ability of an orally available small molecule of FoxO1 inhibitor, Cpd10, to phenocopy genetic ablation of FoxO1. We evaluated the therapeutic impact of genetic ablation or chemical inhibition of FoxO1 on insulin-deficient diabetes in Ins2Akita/+ mice. RESULTS: Pan-intestinal epithelial FoxO1 ablation expanded the EEC pool, induced β-like cells, and improved glucose tolerance in Ins2Akita/+ mice. This genetic effect was phenocopied by Cpd10. Cpd10 induced β-like cells that released insulin in response to glucose in gut organoids, and this effect was enhanced by the Notch inhibitor, DBZ. In Ins2Akita/+ mice, a five-day course of either Cpd10 or DBZ induced intestinal insulin-immunoreactive β-like cells, lowered glycemia, and increased plasma insulin levels without apparent adverse effects. CONCLUSION: These results provide proof of principle of gut cell conversion into β-like cells by a small molecule FoxO1 inhibitor, paving the way for clinical applications.
  • Takumi Kitamoto, Tetsuo Nishikawa
    International journal of molecular sciences 23(16) 2022年8月12日  査読有り筆頭著者責任著者
    Hypertension due to primary aldosteronism poses a risk of severe cardiovascular complications compared to essential hypertension. The discovery of the KCNJ5 somatic mutation in aldosteroene producing adenoma (APA) in 2011 and the development of specific CYP11B2 antibodies in 2012 have greatly advanced our understanding of the pathophysiology of primary aldosteronism. In particular, the presence of CYP11B2-positive aldosterone-producing micronodules (APMs) in the adrenal glands of normotensive individuals and the presence of renin-independent aldosterone excess in normotensive subjects demonstrated the continuum of the pathogenesis of PA. Furthermore, among the aldosterone driver mutations which incur excessive aldosterone secretion, KCNJ5 was a major somatic mutation in APA, while CACNA1D is a leading somatic mutation in APMs and idiopathic hyperaldosteronism (IHA), suggesting a distinctive pathogenesis between APA and IHA. Although the functional detail of APMs has not been still uncovered, its impact on the pathogenesis of PA is gradually being revealed. In this review, we summarize the integrated findings regarding APA, APM or diffuse hyperplasia defined by novel CYP11B2, and aldosterone driver mutations. Following this, we discuss the clinical implications of KCNJ5 mutations to support better cardiovascular outcomes of primary aldosteronism.
  • María Concepción Izquierdo, Niroshan Shanmugarajah, Samuel X Lee, Michael J Kraakman, Marit Westerterp, Takumi Kitamoto, Michael Harris, Joshua R Cook, Galina A Gusarova, Kendra Zhong, Elijah Marbuary, InSug O-Sullivan, Nikolaus Rasmus, Stefania Camastra, Terry G Unterman, Ele Ferrannini, Barry E Hurwitz, Rebecca A Haeusler
    The Journal of clinical investigation 132(7) 2022年4月1日  査読有り
    Multiple beneficial cardiovascular effects of HDL depend on sphingosine-1-phosphate (S1P). S1P associates with HDL by binding to apolipoprotein M (ApoM). Insulin resistance is a major driver of dyslipidemia and cardiovascular risk. However, the mechanisms linking alterations in insulin signaling with plasma lipoprotein metabolism are incompletely understood. The insulin-repressible FoxO transcription factors mediate key effects of hepatic insulin action on glucose and lipoprotein metabolism. This work tested whether hepatic insulin signaling regulates HDL-S1P and aimed to identify the underlying molecular mechanisms. We report that insulin-resistant, nondiabetic individuals had decreased HDL-S1P levels, but no change in total plasma S1P. This also occurred in insulin-resistant db/db mice, which had low ApoM and a specific reduction of S1P in the HDL fraction, with no change in total plasma S1P levels. Using mice lacking hepatic FoxOs (L-FoxO1,3,4), we found that hepatic FoxOs were required for ApoM expression. Total plasma S1P levels were similar to those in controls, but S1P was nearly absent from HDL and was instead increased in the lipoprotein-depleted plasma fraction. This phenotype was restored to normal by rescuing ApoM in L-FoxO1,3,4 mice. Our findings show that insulin resistance in humans and mice is associated with decreased HDL-associated S1P. Our study shows that hepatic FoxO transcription factors are regulators of the ApoM/S1P pathway.
  • Du W, Wang J, Kuo T, Wang L, McKimpson WM, Son J, Watanabe H, Kitamoto T, Lee Y, Ratner LE, McCune K, Chen Y, Grubbs BH, Thornton ME, Fan J, Accili D
    2022年3月  
  • Wendy M McKimpson, Taiyi Kuo, Takumi Kitamoto, Sei Higuchi, Jason C Mills, Rebecca A Haeusler, Domenico Accili
    Gastro hep advances 1(5) 733-745 2022年  査読有り
    BACKGROUND AND AIMS: Stomach cells can be converted to insulin-producing cells by Neurog3, MafA, and Pdxl over-expression. Enteroendocrine cells can be similarly made to produce insulin by the deletion of FOXO1. Characteristics and functional properties of FOXO1-expressing stomach cells are not known. METHODS: Using mice bearing a FOXO1-GFP knock-in allele and primary cell cultures, we examined the identity of FOXO1-expressing stomach cells and analyzed their features through loss-of-function studies with red-to-green fluorescent reporters. RESULTS: FOXO1 localizes to a subset of Neurog3 and parietal cells. FOXO1 deletion ex vivo or in vivo using Neurog3-cre or Atp4b-cre increased numbers of parietal cells, generated insulin- and C-peptide-immunoreactive cells, and raised Neurog3 messenger RNA. Gene expression and ChIP- seq experiments identified the cell cycle regulator cyclin E1 (CCNE1) as a FOXO1 target. CONCLUSION: FOXO1 is expressed in a subset of stomach cells. Its ablation increases parietal cells and yields insulin-immunoreactive cells, consistent with a role in lineage determination.
  • Takuya Minamizuka, Masaya Koshizaka, Mayumi Shoji, Masaya Yamaga, Aiko Hayashi, Kana Ide, Shintaro Ide, Takumi Kitamoto, Kenichi Sakamoto, Akiko Hattori, Takahiro Ishikawa, Junji Kobayashi, Yoshiro Maezawa, Kazuki Kobayashi, Minoru Takemoto, Masaru Inagaki, Akira Endo, Koutaro Yokote
    Asia Pacific journal of clinical nutrition 30(3) 424-435 2021年9月  査読有り
    BACKGROUND AND OBJECTIVES: Red yeast rice contains monacolin K, an inhibitor of cholesterol synthesis, and gamma-aminobutyric acid, a neurotransmitter. The daily dose of red yeast rice and monacolin K in previous studies was relatively high; therefore, there were safety concerns. We aimed to examine the effects of low daily dose red yeast rice on arteriosclerosis in patients with mild dyslipidemia. METHODS AND STUDY DESIGN: Eighteen patients without known cardiovascular disease and unsatisfactory low-density lipoprotein cholesterol (3.96±0.19 mmol/L) controlled only by diet therapy were randomly allocated to receive low dose red yeast rice (200 mg/day) containing 2 mg monacolin K or diet therapy alone for 8 weeks. The primary outcome was the absolute change in low-density lipoprotein cholesterol. Secondary outcomes included total cholesterol, apolipoprotein B, and blood pressure. RESULTS: Low-density lipoprotein cholesterol decreased significantly in the red yeast rice group than in the diet therapy group (median [interquartile range]: control -0.20 [-0.62, 1.19] mmol/L vs. red yeast rice -0.96 [-1.05, -0.34] mmol/L, p=0.030). The red yeast rice group also exhibited significant decreases in total cholesterol, apolipoprotein B, and blood pressure. No severe treatment-related adverse effects on muscles, liver, or renal function were observed. CONCLUSIONS: We found that patients in the red yeast rice group exhibited significant reductions in lowdensity lipoprotein cholesterol, total cholesterol, apolipoprotein B, and blood pressure without any recognised adverse effect. This suggests that low daily dose red yeast rice could reduce cardiovascular risk in patients with dyslipidemia.
  • Kitamoto T, Kuo T, Okabe A, Kaneda A, Accili D
    Proc Natl Acad Sci U S A. in press(45) 2021年9月  査読有り筆頭著者責任著者
    Abnormalities of lipid/lipoprotein and glucose metabolism are hallmarks of hepatic insulin resistance in type 2 diabetes. The former antedate the latter, but the latter become progressively refractory to treatment and contribute to therapeutic failures. It's unclear whether the two processes share a common pathogenesis and what underlies their progressive nature. In this study, we investigated the hypothesis that genes in the lipid/lipoprotein pathway and those in the glucose metabolic pathway are governed by different transcriptional regulatory logics that affect their response to physiologic (fasting/refeeding) as well as pathophysiologic cues (insulin resistance and hyperglycemia). To this end, we obtained genomic and transcriptomic maps of the key insulin-regulated transcription factor, FoxO1, and integrated them with those of CREB, PPAR-α, and glucocorticoid receptor. We found that glucose metabolic genes are primarily regulated by promoter and intergenic enhancers in a fasting-dependent manner, while lipid genes are regulated through fasting-dependent intron enhancers and fasting-independent enhancerless introns. Glucose genes also showed a remarkable transcriptional resiliency (i.e., the ability to compensate following constitutive FoxO1 ablation through an enrichment of active marks at shared PPAR-α/FoxO1 regulatory elements). Unexpectedly, insulin resistance and hyperglycemia were associated with a "spreading" of FoxO1 binding to enhancers and the emergence of unique target sites. We surmise that this unusual pattern correlates with the progressively intractable nature of hepatic insulin resistance. This transcriptional logic provides an integrated model to interpret the combined lipid and glucose abnormalities of type 2 diabetes.
  • Takumi Kitamoto, Ryuichi Saegusa, Takuma Tashiro, Tomomi Sakurai, Koutaro Yokote, Takahiko Tokuyama
    Diabetes therapy : research, treatment and education of diabetes and related disorders 12(6) 1751-1761 2021年6月  査読有り筆頭著者責任著者
    BACKGROUND: Elderly patients with type 2 diabetes (T2DM) are vulnerable to treatment-inducible hypoglycemia, falls, and depressive symptoms. Although it is challenging for elderly patients to adhere to regular exercise, its positive effect on functional ability, glycemic control, and mental wellness offers comprehensive diabetes treatment. In the present study, we aimed to investigate a novel exercise approach for the elderly, focusing on whole-body vibration (WBV). METHODS: This retrospective cohort study was conducted in a primary-care setting at a medical fitness center affiliated with the incorporated medical institution of THY (TOTAL HEALTH YARD). Fourteen (WBV group) and 12 (control group) elderly patients with T2DM undergoing and not undergoing our WBV program, respectively, for > 6 months were analyzed. Primary endpoints were the functional ability changes, evaluated by Timed Up and Go (TUG), Sit-to-Stand test (SST), gait length, and grip test. Secondary endpoints were global glycemic control and questionnaires, namely the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and Geriatric Depression Scale (GDS). All records of exercise adherence and any adverse events were followed. RESULTS: Significant improvements in TUG and SST were found only in the WBV group [TUG: 7.1 ± 0.9, 7.1 ± 0.8 to 7.0 ± 1.0, 6.6 ± 0.9 (s), P = 0.63, 0.01; SST: 10.4 ± 1.9, 11.3 ± 2.4 to 9.7 ± 2.3, 9.5 ± 2.1 (s), P = 0.62, P < 0.01, control vs. WBV group, respectively]. The WBV group demonstrated significant improvement of hemoglobin A1C levels (7.2 ± 0.8 to 6.9 ± 0.5, P < 0.01) and DTSQ and GDS scores, while the control group did not. There were no hypoglycemic events during the study. The WBV program adherence was 93.3 ± 8.0%. CONCLUSION: We demonstrated the favorable effect of WBV training on balance, diabetes treatment, and mood. Therefore, WBV training can be proposed as comprehensive therapy in a safe manner and potentially has a positive effect on health-related quality of life in elderly patients with T2DM.
  • Masaya Koshizaka, Ko Ishikawa, Ryoichi Ishibashi, Yoshiro Maezawa, Kenichi Sakamoto, Daigaku Uchida, Susumu Nakamura, Masaya Yamaga, Hidetaka Yokoh, Akina Kobayashi, Shunichiro Onishi, Kazuki Kobayashi, Jun Ogino, Naotake Hashimoto, Hirotake Tokuyama, Fumio Shimada, Emi Ohara, Takahiro Ishikawa, Mayumi Shoji, Shintaro Ide, Kana Ide, Yusuke Baba, Akiko Hattori, Takumi Kitamoto, Takuro Horikoshi, Ryouta Shimofusa, Sho Takahashi, Kengo Nagashima, Yasunori Sato, Minoru Takemoto, L Kristin Newby, Koutaro Yokote
    Journal of diabetes investigation 12(2) 200-206 2021年2月  査読有り
    AIMS/INTRODUCTION: Recent randomized clinical trials have suggested that sodium-glucose cotransporter 2 inhibitors might reduce cardiovascular events and heart failure, and have renal protective effects. Despite these remarkable benefits, the effects of sodium-glucose cotransporter 2 inhibitors on bone and muscle are unclear. MATERIALS AND METHODS: A subanalysis of a randomized controlled study was carried out to evaluate the effects of the sodium-glucose cotransporter 2 inhibitor, ipragliflozin, versus metformin on bone and muscle in Japanese patients with type 2 diabetes mellitus (baseline body mass index ≥22 kg/m2 and hemoglobin A1c 7-10%) who were already receiving sitagliptin. These patients were randomly administered ipragliflozin 50 mg or metformin 1,000-1,500 mg daily. The effects of these medications on the bone formation marker, bone alkali phosphatase; the bone resorption marker, tartrate-resistant acid phosphatase 5b (TRACP-5b); handgrip strength; abdominal cross-sectional muscle area; and bone density of the fourth lumbar vertebra were evaluated. RESULTS: After 24 weeks of treatment, the changes in bone density of the fourth lumbar vertebra, handgrip strength and abdominal cross-sectional muscle area were not significantly different between the two groups. However, TRACP-5b levels increased in patients treated with ipragliflozin compared with patients treated with metformin (median 11.94 vs -10.30%, P < 0.0001), showing that ipragliflozin can promote bone resorption. CONCLUSIONS: There were no adverse effects on bone or muscle when sitagliptin was used in combination with either ipragliflozin or metformin. However, ipragliflozin combination increased the levels of TRACP-5b. A long-term study is required to further understand the effects of this TRACP-5b increase caused by ipragliflozin.
  • Kosuke Inoue, Takumi Kitamoto, Yuya Tsurutani, Jun Saito, Masao Omura, Tetsuo Nishikawa
    Frontiers in endocrinology 12 645488-645488 2021年  査読有り
    The hypothalamus-pituitary-adrenal (HPA) axis plays an important role in primary aldosteronism. Aldosterone biosynthesis is regulated not only by angiotensin II in the renin-angiotensin-aldosterone system, but also by adrenocorticotropic hormone (ACTH), one of the key components of the HPA axis. Although previous studies have reported cortisol cosecretion in primary aldosteronism, particularly aldosterone-producing adenoma (APA), the clinical relevance of such aldosterone and cortisol cosecretion from APA and hypertension or other metabolic disorders has not been fully established. Several somatic mutations including KCNJ5 and CACNA1D are known to induce autonomous production of aldosterone in APA, and the aldosterone responsiveness to ACTH may vary according to each mutation. The ACTH stimulation test has been reported to be a useful tool to distinguish the subtypes of primary aldosteronism (e.g., unilateral vs bilateral) in some studies, but it has not been commonly applied in clinical practice due to limited evidence. Given the recent advancement of imaging, omics research, and computational approach, it is important to summarize the most updated evidence to disentangle the potential impact of cortisol excess in primary aldosteronism and whether the ACTH stimulation test needs to be considered during the diagnostic process of primary aldosteronism. In this article, we conducted a systematic review of epidemiological studies about (i) cortisol cosecretion in primary aldosteronism and (ii) the ACTH stimulation test for the diagnosis of primary aldosteronism (including subtype diagnosis). Then, we discussed potential biases (e.g., confounding bias, overadjustment, information bias, selection bias, and sampling bias) in the previous studies and introduced some advanced epidemiological/statistical methods to minimize these limitations. A better understanding of biases and epidemiological perspective on this topic would allow us to produce further robust evidence and balanced discussion about the causal mechanisms involving the HPA axis and clinical usefulness of the ACTH stimulation test among patients with primary aldosteronism.
  • Takumi Kitamoto, Kanako Kiriyama Kitamoto, Masao Omura, Tomoko Takiguchi, Yuya Tsurutani, Haremaru Kubo, Yuto Yamazaki, Hironobu Sasano, Jun Saito, Tetsuo Nishikawa
    Hypertension (Dallas, Tex. : 1979) 76(3) 976-984 2020年9月  査読有り筆頭著者
    Segmental selective adrenal venous sampling (sAVS) elucidates an intraadrenal aldosterone activity map (IAMap), which allows us to design a novel surgical treatment strategy for patients with primary aldosteronism. We evaluated the usefulness of sAVS by analyzing 278 patients with whom we had prospectively used IAMap using the criteria of sAVS for surgical indication between 2009 and 2015. We evaluated its diagnostic accuracy using pathological and postsurgical biochemical and clinical outcomes. One hundred twenty and 158 patients were diagnosed with unilateral and bilateral disease, respectively, through sAVS. The concordance of lateralization diagnosis with computed tomography imaging was 66.6%. Among the unilateral patients, we performed partial adrenalectomy in 68 patients whose IAMap showed focal aldosterone hypersecretion from computed tomography-detectable tumor in the affected adrenal gland. All of them achieved complete biochemical success 1 year after surgery. Furthermore, 25 of 158 bilateral disease patients underwent surgical resection because they were preoperatively diagnosed as bilateral aldosterone-producing adenomas by IAMap. These cases showed complete or partial biochemical success (28.0% and 72.0%, respectively); 36.0% showed complete clinical success. Pathological studies demonstrated that all 145 resected specimens possessed aldosterone-producing adenoma or multiple nodules (132 and 13 cases, respectively), and none showed diffuse hyperplasia. IAMap accurately diagnosed both bilateral and unilateral aldosterone-producing adenomas and diffuse hyperplasia before surgery. sAVS allows a novel surgical strategy for selected PA patients with favorable outcomes.
  • Jason Fan, Wen Du, Ja Young Kim-Muller, Jinsook Son, Taiyi Kuo, Delfina Larrea, Christian Garcia, Takumi Kitamoto, Michael J Kraakman, Edward Owusu-Ansah, Vincenzo Cirulli, Domenico Accili
    Molecular metabolism 34 97-111 2020年4月  査読有り
    OBJECTIVE: Diabetes is characterized by pancreatic β-cell dedifferentiation. Dedifferentiating β cells inappropriately metabolize lipids over carbohydrates and exhibit impaired mitochondrial oxidative phosphorylation. However, the mechanism linking the β-cell's response to an adverse metabolic environment with impaired mitochondrial function remains unclear. METHODS: Here we report that the oxidoreductase cytochrome b5 reductase 3 (Cyb5r3) links FoxO1 signaling to β-cell stimulus/secretion coupling by regulating mitochondrial function, reactive oxygen species generation, and nicotinamide actin dysfunction (NAD)/reduced nicotinamide actin dysfunction (NADH) ratios. RESULTS: The expression of Cyb5r3 is decreased in FoxO1-deficient β cells. Mice with β-cell-specific deletion of Cyb5r3 have impaired insulin secretion, resulting in glucose intolerance and diet-induced hyperglycemia. Cyb5r3-deficient β cells have a blunted respiratory response to glucose and display extensive mitochondrial and secretory granule abnormalities, consistent with altered differentiation. Moreover, FoxO1 is unable to maintain expression of key differentiation markers in Cyb5r3-deficient β cells, suggesting that Cyb5r3 is required for FoxO1-dependent lineage stability. CONCLUSIONS: The findings highlight a pathway linking FoxO1 to mitochondrial dysfunction that can mediate β-cell failure.
  • Masaya Koshizaka, Ko Ishikawa, Ryoichi Ishibashi, Yoshiro Maezawa, Kenichi Sakamoto, Daigaku Uchida, Susumu Nakamura, Masaya Yamaga, Hidetaka Yokoh, Akina Kobayashi, Shunichiro Onishi, Kazuki Kobayashi, Jun Ogino, Naotake Hashimoto, Hirotake Tokuyama, Fumio Shimada, Emi Ohara, Takahiro Ishikawa, Mayumi Shoji, Shintaro Ide, Kana Ide, Yusuke Baba, Akiko Hattori, Takumi Kitamoto, Takuro Horikoshi, Ryota Shimofusa, Sho Takahashi, Kengo Nagashima, Yasunori Sato, Minoru Takemoto, Laura Kristin Newby, Koutaro Yokote
    Diabetes, obesity & metabolism 21(8) 1990-1995 2019年8月  査読有り
    A prospective, multicentre, open-label, blinded-endpoint, randomized controlled study was conducted to evaluate the efficacy of treatment with ipragliflozin (sodium-dependent glucose transporter-2 inhibitor) versus metformin for visceral fat reduction and glycaemic control among Japanese patients with type 2 diabetes treated with sitagliptin, HbA1c levels of 7%-10%, and body mass index (BMI) ≥ 22 kg/m2 . Patients were randomly assigned (1:1) to receive ipragliflozin 50 mg or metformin 1000-1500 mg daily. The primary outcome was change in visceral fat area as measured by computed tomography after 24 weeks of therapy. The secondary outcomes were effects on glucose metabolism and lipid metabolism. Mean percentage reduction in visceral fat area was significantly greater in the ipragliflozin group than in the metformin group (-12.06% vs. -3.65%, P = 0.040). Ipragliflozin also significantly reduced BMI, subcutaneous fat area, waist circumference, fasting insulin, and homeostatic model assessment (HOMA)-resistance, and increased HDL-cholesterol levels. Metformin significantly reduced HbA1c and LDL-cholesterol levels and increased HOMA-beta. There were no severe adverse events. The use of ipragliflozin or metformin in combination with dipeptidyl peptidase-4 inhibitors, widely used in Japan, may have beneficial effects in ameliorating multiple cardiovascular risk factors.
  • Liheng Wang, Qiongming Liu, Takumi Kitamoto, Junjie Hou, Jun Qin, Domenico Accili
    Diabetes 68(6) 1156-1167 2019年6月  査読有り
    Hepatocyte glucose production is a complex process that integrates cell-autonomous mechanisms with cellular signaling, enzyme activity modulation, and gene transcription. Transcriptional mechanisms controlling glucose production are redundant and involve nuclear hormone receptors and unliganded transcription factors (TFs). Our knowledge of this circuitry is incomplete. Here we used DNA affinity purification followed by mass spectrometry to probe the network of hormone-regulated TFs by using phosphoenolpyruvate carboxykinase (Pck1) and glucose-6-phosphatase (G6pc) in liver and primary hepatocytes as model systems. The repertoire of insulin-regulated TFs is unexpectedly broad and diverse. Whereas in liver the two test promoters are regulated by largely overlapping sets of TFs, in primary hepatocytes Pck1 and G6pc regulation diverges. Insulin treatment preferentially results in increased occupancy by the two promoters, consistent with a model in which the hormone's primary role is to recruit corepressors rather than to clear activators. Nine insulin-responsive TFs are present in both models, but only FoxK1, FoxA2, ZFP91, and ZHX3 require an intact Pck1p insulin response sequence for binding. Knockdown of FoxK1 in primary hepatocytes decreased both glucose production and insulin's ability to suppress it. The findings expand the repertoire of insulin-dependent TFs and identify FoxK1 as a contributor to insulin signaling.
  • Kosuke Inoue, Yuto Yamazaki, Takumi Kitamoto, Rei Hirose, Jun Saito, Masao Omura, Hironobu Sasano, Tetsuo Nishikawa
    The Journal of clinical endocrinology and metabolism 103(9) 3477-3485 2018年9月1日  査読有り
    Context: Aldosterone biosynthesis is regulated principally by ACTH and gene mutations as well as by angiotensin II and serum potassium. In addition, previous studies have reported the potential effects of KCNJ5 mutations in aldosterone-producing adenoma (APA) on cardiovascular diseases. However, responsiveness to ACTH in APAs according to potassium inwardly rectifying channel, subfamily J, member 5 (KCNJ5) mutations remains unknown. Objective: To investigate KCNJ5 genotype-specific differences in aldosterone biosynthesis in response to ACTH stimulation. Design and Setting: A cross-sectional study through retrieval of clinical records. Participants: One hundred forty-one patients aged ≥20 years with APA were examined. Main Outcome Measures: Associations between KCNJ5 mutations and clinical parameters reflecting the renin-angiotensin system [saline infusion test (SIT)] and ACTH pathways [dexamethasone suppression test (DST)]. Results: KCNJ5 mutations were detected in 107 cases. In the crude comparison, patients with mutations in KCNJ5 had higher plasma aldosterone concentrations (PACs) both at baseline and after the SIT. PAC after the DST showed a significant inverse association with KCNJ5 genotypes after controlling for age, sex, tumor size, and PAC after the SIT. Immunohistochemical analysis of 101 cases revealed more abundant immunoreactivity of CYP11B1 and CYP17 in the KCNJ5-mutated group than in the KCNJ5 wild-type group. Conclusion: This report of marked suppression of PAC by dexamethasone in patients with KCNJ5-mutated APAs indicates that such APAs respond to endogenous ACTH more readily than APAs in nonmutated cases. Further molecular and epidemiologic studies are required to validate our results and clarify the clinical effectiveness of the DST for predicting KCNJ5 mutations before adrenalectomy.
  • Yuto Yamazaki, Kei Omata, Yuta Tezuka, Yoshikiyo Ono, Ryo Morimoto, Yuzu Adachi, Kazue Ise, Yasuhiro Nakamura, Celso E Gomez-Sanchez, Yukiko Shibahara, Takumi Kitamoto, Tetsuo Nishikawa, Sadayoshi Ito, Fumitoshi Satoh, Hironobu Sasano
    Hypertension (Dallas, Tex. : 1979) 72(3) 632-640 2018年9月  査読有り
    Aldosterone-producing adenomas (APAs) harbor marked intratumoral heterogeneity in terms of morphology, steroidogenesis, and genetics. However, an association of biological significance of morphologically identified tumor cell subtypes and genotypes is virtually unknown. KCNJ5 mutation is most frequently detected and generally considered a curable phenotype by adrenalectomy. Therefore, to explore the biological significance of KCNJ5 mutation in APA based on intracellular hormonal activities, 35 consecutively selected APAs (n=18; KCNJ5 mutated, n=17; wild type) were quantitatively examined in the whole tumor areas by newly developed digital image analysis incorporating their histological and ultrastructural features (14 cells from 2 KCNJ5-mutated APAs and 15 cells from 1 wild type) and CYP11B2 immunoreactivity. Results demonstrated that KCNJ5-mutated APAs had significantly lower nuclear/cytoplasm ratio and more abundant clear cells than wild type. CYP11B2 immunoreactivity was not significantly different between these genotypes, but a significant correlation was detected between the proportion of clear cells and CYP11B2 immunoreactivity in all of the APAs examined. CYP11B2 was predominantly immunolocalized in clear cells in KCNJ5-mutated APAs. Quantitative ultrastructural analysis revealed that KCNJ5-mutated APAs had significantly more abundant and smaller-sized mitochondria with well-developed cristae than wild type, whereas wild type had more abundant lipid droplets per unit area despite the small number of the cases examined. Our results did provide the novel insights into the morphological features of APA based on their biological significance. KCNJ5-mutated APAs were characterized by predominance of enlarged lipid-rich clear cells possibly resulting in increased neoplastic aldosterone biosynthesis.
  • Ryoichi Ishibashi, Minoru Takemoto, Yuya Tsurutani, Masayuki Kuroda, Makoto Ogawa, Hanae Wakabayashi, Noriko Uesugi, Michio Nagata, Naofumi Imai, Akiko Hattori, Kenichi Sakamoto, Takumi Kitamoto, Yoshiro Maezawa, Ichiei Narita, Sadayuki Hiroi, Ayaka Furuta, Takashi Miida, Koutaro Yokote
    Journal of Clinical Lipidology 12(4) 888-897.e2 2018年7月  査読有り
    BACKGROUND: Recessive inherited disorder lecithin-cholesterol acyltransferase (LCAT) deficiency causes severe hypocholesterolemia and nephrotic syndrome. Characteristic lipoprotein subfractions have been observed in familial LCAT deficiency (FLD) with renal damage. OBJECTIVE: We described a case of acquired LCAT deficiencies with literature review. METHODS: The lipoprotein profiles examined by gel permeation-high-performance liquid chromatography (GP-HPLC) and native 2-dimensional electrophoresis before and after prednisolone (PSL) treatment. RESULTS: Here we describe the case of a 67-year-old man with severely low levels of cholesterol. The serum LCAT activity was undetectable, and autoantibodies against it were detected. The patient developed nephrotic syndrome at the age of 70 years. Renal biopsy revealed not only membranous glomerulonephritis but also lesions similar to those seen in FLD. We initiated PSL treatment, which resulted in remission of the nephrotic syndrome. In GP-HPLC analysis, lipoprotein profile was similar to that of FLD although lipoprotein X level was low. Acquired LCAT deficiencies are extremely rare with only 7 known cases including ours. Patients with undetectable LCAT activity levels develop nephrotic syndrome that requires PSL treatment; cases whose LCAT activity levels can be determined may also develop nephrotic syndrome, but spontaneously recover. CONCLUSION: Lipoprotein X may play a role in the development of renal impairment in individuals with FLD. However, the effect might be less significant in individuals with acquired LCAT deficiency.
  • Takumi Kitamoto, Kenichi Sakurai, Eun Young Lee, Koutaro Yokote, Domenico Accili, Takashi Miki
    Metabolism: clinical and experimental 82 100-110 2018年5月  査読有り筆頭著者
    OBJECTIVE: Pancreatic β-cell mass and function are critical in glucose homeostasis. Their regulatory mechanisms have been studied principally under experimental conditions of reduced β-cell numbers, such as β-cell ablation and partial pancreatectomy. In the present study, we generated an opposite mouse model with an excessive amount of ectopic β-cells, and analyzed its consequence on β-cell mass and survival. METHODS: Mice underwent sub-renal transplantation (SRT) of pseudo-islets generated from a pancreatic β-cell line MIN6 or intra-pancreatic transplantation (IPT) of MIN6 cells, and morphological and functional changes of their endocrine pancreata were analyzed. Cellular fate of pancreatic β-cells after transplantation was traced using RipCre:Rosa26-tdTomato mice. By using MIN6 cells, we evaluated the roles of extracellular glucose, membrane potential, and insulin signaling on β-cell survival. RESULTS: SRT mice developed severe, progressive hypoglycemia associated with marked reduction in insulin-positive (Ins+) cell mass and apparent increase in apoptotic Ins+ cells. In in vitro experiments of MIN6 cells, insulin signaling blockade potently induced cell death, suggesting that local insulin action is required for β-cell survival. In fact, IPT (i.e. transplantation close to endogenous β-cells) resulted in fewer apoptotic Ins+ cells compared with those induced by SRT. On the other hand, β-cell mass was decreased in proportion to the decrease in blood glucose levels in both SRT and IPT mice, suggesting a contribution of hypoglycemia induced by systemic hyperinsulinemia. CONCLUSION: Insulin plays distinct roles in β-cell survival and β-cell mass regulation through its local and systemic actions on β-cells, respectively.
  • Takumi Kitamoto, Masao Omura, Sachiko Suematsu, Jun Saito, Tetsuo Nishikawa
    Journal of hypertension 36(3) 619-627 2018年3月  査読有り筆頭著者
    OBJECTIVE: To investigate the effect of KCNJ5 mutations on the cure of hypertension in patients with aldosterone-producing adenoma (APA) after unilateral adrenalectomy. METHODS: Our study included 142 patients with APA, who were detected with an endocrinological abnormality and diagnosed with hypertension, as confirmed by pathological analysis. We sequenced KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1 from APA tissue samples, and performed a retrospective analysis to determine correlations between wild-type or mutated KCNJ5 and patient clinical characteristics. RESULTS: Somatic KCNJ5 mutations were identified in 106 of 142 patients with APA, 136 of whom had resolution of hyporeninemic-hyperaldosteronemia 1 year after surgery. Of the 136 patients, 81 patients had resolution of hypertension ('Cured group' vs. 'Improved group'). We found increased prevalence of KCNJ5 mutations in the Cured group compared to the Improved group (85.2% vs. 60.0%, respectively; P = 0.002), which was associated with younger age, shorter duration of hypertension, fewer antihypertensive medications, lower BMI, higher aldosterone level, higher estimated glomerular filtration rate, and milder vascular complications. In both groups we found that harbouring a KCNJ5 mutation, taking fewer antihypertensive medications, and the duration of hypertension were independently associated with resolution of hypertension by unilateral adrenalectomy. In patients with KCNJ5-mutated APA, left ventricular hypertrophy was significantly decreased by surgical treatment in patients from either Cured or Improved groups, although those patients with wild-type KCNJ5 showed no change. CONCLUSIONS: Testing for KCNJ5 mutations in young patients with APA may provide a prognostic indication for resolution of hypertension and severity of vascular complications.
  • Aiko Hayashi, Yukari Maeda, Minoru Takemoto, Hirotake Tokuyama, Hisashi Koide, Aya Kitahara, Hideki Hayashi, Takumi Kitamoto, Masaya Yamaga, Kazuki Kobayashi, Koutaro Yokote
    Geriatrics & gerontology international 17(11) 2068-2073 2017年11月  査読有り
    AIM: Laparoscopic sleeve gastrectomy (LSG) has proven to be the most effective strategy for the treatment of morbid obesity, however its efficacy and safety in an aging population has not yet been confirmed. In this study, we evaluated the effectiveness and safety of LSG in elderly obese Japanese patients. METHODS: Three obese individuals aged >60 years and 11 obese individuals aged <60 years who underwent LSG were enrolled. Pre- and postoperative changes after at least 12 months were examined, including bodyweight, body mass index, total weight loss, excess weight loss, bone mineral density and bone-related markers. RESULTS: There were no significant differences between patients aged <60 years and >60 years in terms of percent total weight loss (24.4 ± 11 vs 23 ± 4.4%, respectively) and percent excess weight loss (49.1 ± 23.4 vs 47.6 ± 10 %, respectively). Dual-energy X-ray absorptiometry was carried out before and 12 months after LSG. There were no significant differences in bone mineral density changes at the lumbar spine and femoral neck between the two groups (0.01 ± 0.06 vs 0.02 ± 0.03 g/cm2 , -0.03 ± 0.06 vs -0.08 ± 0.02 g/cm2 , respectively). There were no peri- and postoperative complications. All three patients aged >60 years had reduced bone mineral density in the femoral neck after LSG; one was diagnosed with osteoporosis. CONCLUSIONS: Although the present results suggest that LSG could be of considerable benefit to elderly obese Japanese patients, long-term careful observation after bariatric surgery is especially important in elderly patients to prevent future osteoporosis. Geriatr Gerontol Int 2017; 17: 2068-2073.
  • Masaya Yamaga, Minoru Takemoto, Aki Takada-Watanabe, Naoko Koizumi, Takumi Kitamoto, Kenichi Sakamoto, Takahiro Ishikawa, Masaya Koshizaka, Yoshiro Maezawa, Koutaro Yokote
    Journal of the American Geriatrics Society 65(8) 1853-1856 2017年8月  査読有り
    OBJECTIVES: To determine recent trends in mutation patterns in the WRN gene, which cause Werner syndrome (WS), a rare, inheritable progeroid syndrome in Japan. DESIGN: Retrospective cohort. SETTING: Longitudinal survey of WS and literature search for case reports. PARTICIPANTS: Individuals whose genetic testing their facilities had requested between 2009 and October 2016 (N = 67). MEASUREMENTS: A nationwide epidemiological study was conducted from 2009 to 2011 to improve understanding of the pathology of WS and develop therapeutic guidelines. Since 2009, Chiba University Hospital consecutively evaluated the WRN gene in 67 individuals throughout Japan who had requested genetic testing. A literature search was also conducted for case reports on Japanese WS reported since 1997. RESULTS: A definitive diagnosis of WS was confirmed genetically in 50 of 67 participants. Through the literature search, 16 individuals diagnosed genetically with WS were identified. Of these 66 individuals with WS, 42 were homozygous for a WRN mutation, and 21 were compound heterozygotes. One novel mutant allele was identified in an individual with the compound heterozygous genotype. The proportion of compound heterozygotes (31.8%) was significantly greater than reported previously (14.2%), indicating that the incidence of consanguineous marriage of parents has decreased. CONCLUSION: The increased frequency of individuals with WS with the compound heterozygous genotype is a recent trend in Japan. A long-term follow-up study on WRN homozygotes and compound heterozygotes will allow the relationship between WRN genotype and clinical severity of WS to be evaluated in the future.
  • Emi Ohara, Hirotake Tokuyama, Takumi Kitamoto, Aya Kitahara, Aiko Hayashi, Hideki Hayashi, Minoru Takemoto, Koutaro Yokote
    Obesity surgery 27(8) 2214-2217 2017年8月  査読有り
    Because growth hormone (GH) secretion is reportedly decreased in obese patients, we examined not only the factors associated with the decreased GH secretion but also GH response to the GH-releasing peptide (GHRP)-2-load test before and after laparoscopic gastrectomy (LSG). The study comprised 28 individuals aged 19-65 years [mean body mass index (BMI), 39.4 ± 9.4 kg/m2]. In the univariate analysis, GH secretion peaks correlated negatively with BMI (r = -0.59, p = 0.001), visceral adipose tissue (r = -0.47, p = 0.005), and subcutaneous adipose tissue (r = -0.40, p = 0.04). In the two obese patients, the response to the GHRP-2-load test markedly improved by weight loss 12 months after LSG. In conclusion, GH secretion was decreased in obese patients and improved by LSG.
  • Takumi Kitamoto, Sachiko Suematsu, Yuto Yamazaki, Yasuhiro Nakamura, Hironobu Sasano, Yoko Matsuzawa, Jun Saito, Masao Omura, Tetsuo Nishikawa
    The Journal of clinical endocrinology and metabolism 101(2) 494-503 2016年2月  査読有り筆頭著者
    OBJECT: This comparative study clarified the clinical characteristics and in vitro steroidogenic activities of aldosterone-producing adenomas (APAs) harboring ATPase or CACNA1D gene mutations. DESIGN AND PATIENTS: Genetic testing was performed on 159 unilateral APAs. Somatic ATPase and CACNA1D gene mutations were analyzed in 42 APA tissues without KCNJ5 gene mutations. RESULTS: ATP1A1, ATP2B3, and CACNA1D mutations were detected in one, four, and four patients, respectively. Compared with patients without KCNJ5, ATPase, or CACNA1D mutations (wild type), ATPase mutations tended to have more severe hyperaldosteronism and smaller tumors; those with CACNA1D mutations had clinical characteristics and tumor sizes similar to those with wild-type genes. APAs with ATPase mutations were composed mainly of compact eosinophilic tumor cells, whereas CACNA1D mutations resulted in predominantly clear tumor cells. Aldosterone production in APA cells with ATP2B3 mutations were more responsive to dibutyryl cAMP, whereas those with CACNA1D mutations were more responsive to adrenocorticotropic hormone than the wild-type cells. CONCLUSION: APAs with ATPase mutations demonstrated a potentially severe primary aldosteronism phenotype, whereas those with CACNA1D mutations displayed characteristics similar to wild-type APAs. The status of stimulated aldosterone production was also different according to the cell types, suggesting that the regulatory effects of adrenocorticotropic hormone on aldosterone synthesis could possibly vary according to the intracellular signaling involved in hormone production.
  • Aiko Hayashi, Minoru Takemoto, Takumi Kitamoto, Kazuki Kobayashi, Koutaro Yokote
    DIABETES 64 A327-A327 2015年6月  
  • Tetsuo Nishikawa, Takumi Kitamoto, Yoko Matsuzawa, Jun Saito, Masao Omura
    Journal of Endocrinology and Diabetes 2(1) 2015年  査読有り招待有り
  • Takumi Kitamoto, Sachiko Suematsu, Yoko Matsuzawa, Jun Saito, Masao Omura, Tetsuo Nishikawa
    Journal of atherosclerosis and thrombosis 22(2) 191-200 2015年  査読有り筆頭著者
    AIM: Our objective was to evaluate the incidence of cardiovascular complications before and after unilateral adrenalectomy in patients with and without KCNJ5 gene mutations harboring aldosterone-producing adenoma (APA). METHODS: A total of 108 APA patients were evaluated in the present study. We compared the clinical characteristics and laboratory findings according to the cardiovascular complications in the patients with or without KCNJ5 gene mutations harboring APA after excluding five APA patients with ATPase or CACNA1D gene mutations. RESULTS: There were 75 and 28 APA patients with somatic mutations of KCNJ5 (p.G151R, p.L168R, p.E145Q, p.T158A or 157del) and no mutations, respectively. There were no double mutations in any of the subjects. The KCNJ5-mutated and wild type groups demonstrated similar advances in left ventricular hypertrophy prior to surgery, although the mutated group was significantly younger, with higher plasma and urine aldosterone levels, than the wild type group (48.2 vs. 55.8 (years old); p<0.001, 436.0 vs. 247 (pg/mL); p<0.001, 22.2 vs. 12.6 (μg/day); p=0.008). Both groups displayed postoperative improvements in hyperaldosteronism and hypertension. Moreover, the LV mass index (LVMI) significantly improved after surgery in the mutated group (p<0.001), but not in the wild type group (p=0.256). A multiple linear regression analysis showed that an improvement in the LVMI was independently associated with KCNJ5 mutations and the plasma aldosterone level in that order (p=0.034, 0.050, respectively). CONCLUSION: The present findings clearly demonstrated that KCNJ5 mutations are common among Japanese APA patients (frequency: 69.4%). In this study, the KCNJ5-mutated group demonstrated significant postoperative improvements in LVMI, possibly due to strong autonomous aldosterone production. Hence, it is necessary to precisely diagnose younger APA patients possessing a strong capacity for aldosterone production due to KCNJ5 gene mutations, as such cases may be easily complicated by cardiovascular events.
  • Noriko Kimura, Kazuhiro Takekoshi, Akira Horii, Ryo Morimoto, Tsuneo Imai, Yutaka Oki, Tomohito Saito, Sanae Midorikawa, Tadashi Arao, Chiho Sugisawa, Masanobu Yamada, Yuichi Otuka, Isao Kurihara, Kokichi Sugano, Minoru Nakane, Atsushi Fukuuchi, Takumi Kitamoto, Jun Saito, Tetsuo Nishikawa, Mitsuhide Naruse
    Endocrine-related cancer 21(3) L13-6 2014年6月  査読有り
  • Takumi Kitamoto, Kenichi Sakurai, Kaori Tachibana, Hidetaka Yokoh, Ko Ishikawa, Takashi Miki, Koutaro Yokote
    Diabetes care 36(7) e89 2013年7月  査読有り筆頭著者
  • Takumi Kitamoto, Minoru Takemoto, Masaki Fujimoto, Takahiro Ishikawa, Shunichiro Onishi, Emiko Okabe, Ryoichi Ishibashi, Kazuki Kobayashi, Harukiyo Kawamura, Koutaro Yokote
    Diabetes care 35(12) e83 2012年12月  査読有り筆頭著者

MISC

 31

共同研究・競争的資金等の研究課題

 1

その他

 2
  • 2023年12月
    プレスリリース 千葉大学HP https://www.chiba-u.ac.jp/news/research-collab/--_7.html Research map https://researchmap.jp/press_releases/press_releases/view/633014/0411119647f9c0083430eec2a5debfb3?frame_id=1601185 日本において約4,300万人いるとされている高血圧患者さんの約10%に当たる430万人以上の方が、「原発性アルドステロン症 (PA)」という病気が原因であると推定されています。PAによる高血圧は手術によって治癒しうる病気ですが、この判断には、超選択的副腎静脈採血 (sAVS)という最先端の診断技術が必要です。しかし、sAVSはまだ限られた施設でしか利用できません。そこで、千葉大学医学部附属病院の北本匠助教、IBM Researchの井手剛博士、横浜労災病院の西川哲男名誉院長、鶴谷悠也部長、東北大学大学院医学系研究科病理診断学分野の佐藤文俊客員教授、東北大学病院糖尿病代謝・内分泌内科の手塚雄太医員、市立札幌病院和田典男部長の研究チームは、機械学習を応用した独自のアルゴリズムを開発し、一般的な診療情報を用いてPA患者さんのうち、sAVSによる診断が必要な方を35%まで絞り込むことに成功しました。この成果により、sAVSを実施することなく65%にあたる患者さんの治療方針を94%の精度で決定することが可能となったため、不必要な入院・採血等の負担を減らすことができます。同時に、35%のsAVSを必要とする患者さんのみに診断を実施し「治せる高血圧」をより多く見つけることも実現できます。本研究成果は、科学誌 Scientific Report にて2023年12月11日にオンライン公開されました。
  • 2021年11月
    プレスリリース 千葉大学HP https://www.m.chiba-u.ac.jp/research-topics/211108/ コロンビア大学医学部 北本匠研究員(千葉大学大学院医学研究院特任助教:現在留学中)、Domenico Accili 教授、千葉大学大学院医学研究院 金田篤志教授、岡部篤史助教らの研究チームは、最新技術を駆使し、健康状態及び糖尿病状態で糖代謝制御において重要な役割を持つ転写因子 FoxO1がゲノムに働きかける全体像を、特に糖・脂質代謝の観点から明らかにしました。全ゲノムレベルでインスリンシグナルによる糖と脂質代謝の制御機構の違いが明らかとなったのは世界で初めてです。動物モデルの作成及び、全ゲノム情報の網羅的解析技術を駆使することで、糖尿病で問題となる糖代謝特有の制御領域を特定し、病気によりゲノム上に生じる変化が明らかになりました。この成果により、インスリンの仕組みを応用した今までにない作用機序の薬剤である「選択的インスリン感受性改善薬」という新たな治療法の確立につながることが期待されます。本研究成果は、科学誌「米国科学アカデミー紀要」にて 2021 年 11 月 4 日 (日本時間)にオンライン公開されました。