研究者業績

関根 亜由美

セキネ アユミ  (Sekine Ayumi)

基本情報

所属
千葉大学 大学院医学研究院 特任助教
学位
医学博士(千葉大学)

researchmap会員ID
B000333859

主要な論文

 63
  • Jun Nagata, Ayumi Sekine, Nobuhiro Tanabe, Yu Taniguchi, Keiichi Ishida, Yuki Shiko, Seiichiro Sakao, Koichiro Tatsumi, Takuji Suzuki
    BMC Pulmonary Medicine 22(1) 2022年12月  査読有り責任著者
    Abstract Background The prognostic value of mixed venous oxygen tension (PvO2) at pulmonary hypertension diagnosis treated with selective pulmonary vasodilators remains unclear. This study sought to investigate the association of PvO2 with long-term prognosis in pulmonary arterial hypertension (PAH) and medically treated chronic thromboembolic pulmonary hypertension (CTEPH) and to identify the distinct mechanisms influencing tissue hypoxia in patients with CTEPH or PAH. Methods We retrospectively analyzed data from 138 (age: 50.2 ± 16.6 years, 81.9% women) and 268 (age: 57.4 ± 13.1 years, 72.8% women) patients with PAH and CTEPH, respectively, diagnosed at our institution from 1983 to 2018. We analyzed the survival rates of patients with/without tissue hypoxia (PvO2 < 35 mmHg) and identified their prognostic factors based on the pulmonary hypertension risk stratification guidelines. Results Survival was significantly poorer in patients with tissue hypoxia than in those without it for PAH (P = 0.001) and CTEPH (P = 0.017) treated with selective pulmonary vasodilators. In patients with PAH, PvO2 more strongly correlated with prognosis than other hemodynamic prognostic factors regardless of selective pulmonary vasodilators usage. PvO2 was the only significant prognostic factor in patients with CTEPH treated with pulmonary hypertension medication. Patients with CTEPH experiencing tissue hypoxia exhibited significantly poorer survival than those in the intervention group (P < 0.001). PvO2 more strongly correlated with the cardiac index (CI) than the alveolar-arterial oxygen gradient (A-aDO2) in PAH; whereas in CTEPH, PvO2 was more strongly correlated with A-aDO2 than with CI. Conclusions PvO2 may represent a crucial prognostic factor for pulmonary hypertension. The prognostic impact of tissue hypoxia affects different aspects of PAH and CTEPH, thereby reflecting their distinct pathogenesis.
  • Yumiko Ikubo, Takayuki Jujo Sanada, Koji Hosomi, Jonguk Park, Akira Naito, Hiroki Shoji, Tomoko Misawa, Rika Suda, Ayumi Sekine, Toshihiko Sugiura, Ayako Shigeta, Hinako Nanri, Seiichiro Sakao, Nobuhiro Tanabe, Kenji Mizuguchi, Jun Kunisawa, Takuji Suzuki, Koichiro Tatsumi
    BMC pulmonary medicine 22(1) 138-138 2022年4月8日  査読有り
    Abstract Background The pathogenesis of chronic thromboembolic pulmonary hypertension (CTEPH) is considered to be associated with chronic inflammation; however, the underlying mechanism remains unclear. Recently, altered gut microbiota were found in patients with pulmonary arterial hypertension (PAH) and in experimental PAH models. The aim of this study was to characterize the gut microbiota in patients with CTEPH and assess the relationship between gut dysbiosis and inflammation in CTEPH. Methods In this observational study, fecal samples were collected from 11 patients with CTEPH and 22 healthy participants. The abundance of gut microbiota in these fecal samples was assessed using 16S ribosomal ribonucleic acid (rRNA) gene sequencing. Inflammatory cytokine and endotoxin levels were also assessed in patients with CTEPH and control participants. Results The levels of serum tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were elevated in patients with CTEPH. Plasma endotoxin levels were significantly increased in patients with CTEPH (P < 0.001), and were positively correlated with TNF-α, IL-6, IL-8, and MIP-1α levels. The 16S rRNA gene sequencing and the principal coordinate analysis revealed the distinction in the gut microbiota between patients with CTEPH (P < 0.01) and control participants as well as the decreased bacterial alpha-diversity in patients with CTEPH. A random forest analysis for predicting the distinction in gut microbiota revealed an accuracy of 80.3%. Conclusion The composition of the gut microbiota in patients with CTEPH was distinct from that of healthy participants, which may be associated with the elevated inflammatory cytokines and endotoxins in CTEPH.
  • 酒寄 雅史, 関根 亜由美, 坂尾 誠一郎, 重田 文子, 杉浦 寿彦, 須田 理香, 笠井 大, 内藤 亮, 東海林 寛樹, 田邉 信宏, 巽 浩一郎
    日本呼吸器学会誌 10(増刊) 304-304 2021年4月  
  • Tu L, Desroches-Castan A, Mallet C, Guyon L, Cumont A, Phan C, Robert F, Thuillet R, Bordenave J, Sekine A, Huertas A, Ritvos O, Savale L, Feige JJ, Humbert M, Bailly S, Guignabert C
    Circulation research 124(6) 846-855 2019年3月  査読有り
  • Toshio Suzuki, Yuji Tada, Rintaro Nishimura, Takeshi Kawasaki, Ayumi Sekine, Takashi Urushibara, Fumiaki Kato, Taku Kinoshita, Jun Ikari, James West, Koichiro Tatsumi
    American Journal of Physiology - Lung Cellular and Molecular Physiology 310(11) L1185-L1198 2016年6月1日  
    Pulmonary vascular endothelial function may be impaired by oxidative stress in endotoxemia-derived acute lung injury. Growing evidence suggests that endothelial-to-mesenchymal transition (EndMT) could play a pivotal role in various respiratory diseases however, it remains unclear whether EndMT participates in the injury/repair process of septic acute lung injury. Here, we analyzed lipopolysaccharide (LPS)-treated mice whose total number of pulmonary vascular endothelial cells (PVECs) transiently decreased after production of reactive oxygen species (ROS), while the population of EndMT-PVECs significantly increased. NAD(P)H oxidase inhibition suppressed EndMT of PVECs. Most EndMT-PVECs derived from tissue-resident cells, not from bone marrow, as assessed by mice with chimeric bone marrow. Bromodeoxyuridine-incorporation assays revealed higher proliferation of capillary EndMT-PVECs. In addition, EndMT-PVECs strongly expressed c-kit and CD133. LPS loading to human lung microvascular endothelial cells (HMVEC-Ls) induced reversible EndMT, as evidenced by phenotypic recovery observed after removal of LPS. LPS-induced EndMT-HMVEC-Ls had increased vasculogenic ability, aldehyde dehydrogenase activity, and expression of drug resistance genes, which are also fundamental properties of progenitor cells. Taken together, our results demonstrate that LPS induces EndMT of tissue-resident PVECs during the early phase of acute lung injury, partly mediated by ROS, contributing to increased proliferation of PVECs.
  • Ayumi Sekine, Tetsu Nishiwaki, Rintaro Nishimura, Takeshi Kawasaki, Takashi Urushibara, Rika Suda, Toshio Suzuki, Shin Takayanagi, Jiro Terada, Seiichiro Sakao, Yuji Tada, Atsushi Iwama, Koichiro Tatsumi
    American journal of physiology. Lung cellular and molecular physiology 310(11) L1130-42-42 2016年6月1日  査読有り筆頭著者責任著者
    Pulmonary vascular endothelial cells could contribute to maintain homeostasis in adult lung vasculature. "Tissue-resident" endothelial progenitor cells (EPCs) play pivotal roles in postnatal vasculogenesis, vascular repair, and tissue regeneration; however, their local pulmonary counterparts remain to be defined. To determine whether prominin-1/CD133 expression can be a marker of tissue-resident vascular EPCs in the pulmonary circulation, we examined the origin and characteristics of prominin-1/CD133-positive (Prom1(+)) PVECs considering cell cycle status, viability, histological distribution, and association with pulmonary vascular remodeling. Prom1(+) PVECs exhibited high steady-state transit through the cell cycle compared with Prom1(-) PVECs and exhibited homeostatic cell division as assessed using the label dilution method and mice expressing green fluorescent protein. In addition, Prom1(+) PVECs showed more marked expression of putative EPC markers and drug resistance genes as well as highly increased activation of aldehyde dehydrogenase compared with Prom1(-) PVECs. Bone marrow reconstitution demonstrated that tissue-resident cells were the source of >98% of Prom1(+) PVECs. Immunofluorescence analyses revealed that Prom1(+) PVECs preferentially resided in the arterial vasculature, including the resistant vessels of the lung. The number of Prom1(+) PVECs was higher in developing postnatal lungs. Sorted Prom1(+) PVECs gave rise to colonies and formed fine vascular networks compared with Prom1(-) PVECs. Moreover, Prom1(+) PVECs increased in the monocrotaline and the Su-5416 + hypoxia experimental models of pulmonary vascular remodeling. Our findings indicated that Prom1(+) PVECs exhibited the phenotype of tissue-resident EPCs. The unique biological characteristics of Prom1(+) PVECs predominantly contribute to neovasculogenesis and maintenance of homeostasis in pulmonary vascular tissues.
  • Toshio Suzuki, Yuji Tada, Rintaro Nishimura, Takeshi Kawasaki, Ayumi Sekine, Takashi Urushibara, Fumiaki Kato, Taku Kinoshita, Jun Ikari, James West, Koichiro Tatsumi
    AMERICAN JOURNAL OF PHYSIOLOGY-LUNG CELLULAR AND MOLECULAR PHYSIOLOGY 310(11) L1185-L1198 2016年6月  査読有り
    Pulmonary vascular endothelial function may be impaired by oxidative stress in endotoxemia-derived acute lung injury. Growing evidence suggests that endothelial-to-mesenchymal transition (EndMT) could play a pivotal role in various respiratory diseases; however, it remains unclear whether EndMT participates in the injury/repair process of septic acute lung injury. Here, we analyzed lipopolysaccharide (LPS)-treated mice whose total number of pulmonary vascular endothelial cells (PVECs) transiently decreased after production of reactive oxygen species (ROS), while the population of EndMT-PVECs significantly increased. NAD(P)H oxidase inhibition suppressed EndMT of PVECs. Most EndMT-PVECs derived from tissue-resident cells, not from bone marrow, as assessed by mice with chimeric bone marrow. Bromodeoxyuridine-incorporation assays revealed higher proliferation of capillary EndMT-PVECs. In addition, EndMT-PVECs strongly expressed c-kit and CD133. LPS loading to human lung microvascular endothelial cells (HMVEC-Ls) induced reversible EndMT, as evidenced by phenotypic recovery observed after removal of LPS. LPS-induced EndMT-HMVEC-Ls had increased vasculogenic ability, aldehyde dehydrogenase activity, and expression of drug resistance genes, which are also fundamental properties of progenitor cells. Taken together, our results demonstrate that LPS induces EndMT of tissue-resident PVECs during the early phase of acute lung injury, partly mediated by ROS, contributing to increased proliferation of PVECs.
  • Rintaro Nishimura, Nobuhiro Tanabe, Ayumi Sekine, Hajime Kasai, Rika Suda, Fumiaki Kato, Takayuki Jujo, Toshihiko Sugiura, Ayako Shigeta, Seiichiro Sakao, Koichiro Tatsumi
    Respiration; international review of thoracic diseases 91(2) 132-40 2016年  査読有り
    BACKGROUND: The insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene (ACE) and the C825T polymorphism in the G-protein β3 subunit gene (GNB3) are associated with the efficacy of phosphodiesterase-5 inhibitor (PDE-5I) in erectile dysfunction. In addition, GNB3 genotypes could be associated with clinical worsening in pulmonary hypertension (PH) treated with PDE-5I. However, no studies have described the synergistic effects of gene polymorphisms on drug efficacy in patients with PH. OBJECTIVES: We aimed to examine the effects of combined ACE/GNB3 polymorphisms on the efficacy of PDE-5I in patients with PH. METHODS: This was a retrospective uncontrolled study. Ninety patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic PH (CTEPH) were treated with PDE-5I. Freedom from clinical worsening and pre- and post-treatment parameters, including the 6-min walk distance (6MWD) and serum brain natriuretic peptide (BNP) levels, were compared between patients with ACE/GNB3 II/TT and non-II/TT genotypes. RESULTS: Time to clinical worsening was significantly longer in patients with the II/TT genotype than in those with the non-II/TT genotype (5-year freedom from clinical worsening: 100 vs. 48.8%, respectively; p = 0.018), even in patients with CTEPH alone. Post-treatment 6MWD and BNP levels in patients with the II/TT genotype tended to be better than those in patients with the non-II/TT genotype. The ACE/GNB3 genotype was a significant predictor of clinical worsening, even after adjusting for pulmonary vascular resistance and 6MWD. CONCLUSIONS: ACE and GNB3 polymorphisms may synergistically influence the efficacy of PDE-5I in patients with PH.
  • Takeshi Kawasaki, Tetsu Nishiwaki, Ayumi Sekine, Rintaro Nishimura, Rika Suda, Takashi Urushibara, Toshio Suzuki, Shin Takayanagi, Jiro Terada, Seiichiro Sakao, Koichiro Tatsumi
    American journal of respiratory cell and molecular biology 53(4) 500-12 2015年10月  査読有り
    Vascular disruption is one of the pathological hallmarks in acute respiratory distress syndrome. Bone marrow (BM)-derived circulating endothelial progenitor cells (EPCs) and lung tissue-resident EPCs have been considered to play a pivotal role in pulmonary vascular repair; however, which population is predominant in local pulmonary vasculogenesis remains to be clarified. We therefore examined the origin of EPCs participating in the regenerative process of pulmonary vascular endothelial cells (PVECs) in experimental acute respiratory distress syndrome. Lung samples from mice administered LPS intratracheally were investigated for cell dynamics and EPC functions. Quantitative flow cytometric analysis demonstrated that the number of PVECs decreased by roughly 20% on Day 1 and then recovered on Day 7 of LPS challenge. Bromodeoxyuridine-incorporation assays and immunofluorescence microscopy demonstrated that proliferating PVECs preferentially located in the capillary vessels. Experiments using BM chimera mice revealed that most of the regenerating PVECs were tissue-resident cells, and BM-derived cells hardly engrafted as PVECs. The population of circulating putative phenotypical EPCs decreased during the first week after LPS challenge. The regenerating PVECs were characterized by high colony-forming and vasculogenic capacities, intracellular reactive oxygen species scavenging and aldehyde dehydrogenase activites, and enhanced gene expression of Abcb1b (a drug-resistant gene), suggesting that the population of PVECs included tissue-resident EPCs activated during regenerative process of PVECs. The proliferating PVECs expressed CD34, Flk-1/KDR, and c-kit more strongly and Prom1/CD133 less strongly on the surface than nonproliferating PVECs. Our findings indicated that lung tissue-resident EPCs predominantly contribute to pulmonary vascular repair after endotoxin-induced injury.
  • Rintaro Nishimura, Tetsu Nishiwaki, Takeshi Kawasaki, Ayumi Sekine, Rika Suda, Takashi Urushibara, Toshio Suzuki, Shin Takayanagi, Jiro Terada, Seiichiro Sakao, Koichiro Tatsumi
    American journal of physiology. Lung cellular and molecular physiology 308(8) L746-58-58 2015年4月15日  査読有り
    Exposure to hypoxia induces changes in the structure and functional phenotypes of the cells composing the pulmonary vascular wall from larger to most peripheral vessels. Endothelial progenitor cells (EPCs) may be involved in vascular endothelial repair. Resident EPCs with a high proliferative potential are found in the pulmonary microcirculation. However, their potential location, identification, and functional role have not been clearly established. We investigated whether resident EPCs or bone marrow (BM)-derived EPCs play a major role in hypoxic response of pulmonary vascular endothelial cells (PVECs). Mice were exposed to hypoxia. The number of PVECs transiently decreased followed by an increase in hypoxic animals. Under hypoxic conditions for 1 wk, prominent bromodeoxyuridine incorporation was detected in PVECs. Some Ki67-positive cells were detected among PVECs after 1 wk under hypoxic conditions, especially in the capillaries. To clarify the origin of proliferating endothelial cells, we used BM chimeric mice expressing green fluorescent protein (GFP). The percentage of GFP-positive PVECs was low and constant during hypoxia in BM-transplanted mice, suggesting little engraftment of BM-derived cells in lungs under hypoxia. Proliferating PVECs in hypoxic animals showed increased expression of CD34, suggesting hypoxia-induced gene expression and cell surface antigen of EPC or stem/progenitor cells markers. Isolated PVECs from hypoxic mice showed colony- and tube-forming capacity. The present study indicated that hypoxia could induce proliferation of PVECs, and the origin of these cells might be tissue-resident EPCs.
  • Sekine A, Tanabe N, Sugiura T, Shigeta A, Jujo T, Nishimura R, Sakao S, Kasahara Y, Tatsumi K
    Internal medicine (Tokyo, Japan) 53(4) 291-297 2014年  査読有り筆頭著者責任著者

主要なMISC

 99

講演・口頭発表等

 24

主要な共同研究・競争的資金等の研究課題

 7

学術貢献活動

 6

社会貢献活動

 1