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Dive into the research topics where Masako Nishikawa is active.

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Featured researches published by Masako Nishikawa.


Circulation | 2013

Atorvastatin, Etidronate, or Both in Patients at High Risk for Atherosclerotic Aortic Plaques: A Randomized Controlled Trial

Tetsuya Kawahara; Masako Nishikawa; Chie Kawahara; Tetsuya Inazu; Kunio Sakai; Gen Suzuki

Background— Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta. Methods and Results— A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, −16.4 to −11.3) and 12.3% (95% confidence interval, −14.9 to −9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, −0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (−11.4%) than in the atorvastatin group (−0.9%; P<0.001) and the etidronate group (5.5%; P=0.006). Conclusions— Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.


Journal of Atherosclerosis and Thrombosis | 2015

Lysophosphatidylserine has Bilateral Effects on Macrophages in the Pathogenesis of Atherosclerosis.

Masako Nishikawa; Makoto Kurano; Hitoshi Ikeda; Junken Aoki; Yutaka Yatomi

AIM Lysophospholipids, particularly sphingosine 1-phosphate and lysophosphatidic acid, are known to be involved in the pathogenesis of atherosclerosis; however, the role of lysophosphatidylserine (LysoPS) in the onset of atherosclerotic diseases remains uncertain. METHODS We investigated the effects of LysoPS on the uptake of oxidized low-density lipoprotein (oxLDL) and the modulation of inflammatory mediators and ER stress utilizing RAW264.7 cells and mouse peritoneal macrophages (MPMs). RESULTS We found that LysoPS augmented cholesterol accumulation in both models. Consistent with these findings, LysoPS increased the expression of scavenger receptors (CD36, MSR1, LOX1 and TLR4). Regarding the involvement of these lipids in inflammation, LysoPS significantly decreased the expression of inflammatory mediators in lipopolysaccharide (LPS)-treated RAW264.7 cells and MPMs. LysoPS also attenuated ER stress in LPS-untreated RAW264.7 cells. The expression patterns of LysoPS receptors differed considerably among the LPS-untreated RAW264.7 cells, LPS-treated RAW264.7 cells and MPMs. CONCLUSIONS LysoPS may have proatherosclerotic properties in the setting of foam cell formation as well as antiatherosclerotic effects on inflammation in macrophages.


BBA clinical | 2015

Blood levels of serotonin are specifically correlated with plasma lysophosphatidylserine among the glycero-lysophospholipids

Makoto Kurano; Tomotaka Dohi; Takahiro Nojiri; Tamaki Kobayashi; Yuji Hirowatari; Asuka Inoue; Kuniyuki Kano; Hirotaka Matsumoto; Koji Igarashi; Masako Nishikawa; Katsumi Miyauchi; Hiroyuki Daida; Hitoshi Ikeda; Junken Aoki; Yutaka Yatomi

Backgrounds Glycero-lysophospholipids (glycero-LPLs), which are known to exert potent biological activities, have been demonstrated to be secreted from activated platelets in vitro; however, their association with platelet activation in vivo has not been yet elucidated. In this study, we investigated the correlations between the blood levels of each glycero-LPL and serotonin, a biomarker of platelet activation, in human subjects to elucidate the involvement of platelet activation in glycero-LPLs in vivo. Methods and Results We measured the plasma serotonin levels in 141 consecutive patients undergoing coronary angiography (acute coronary syndrome, n = 38; stable angina pectoris, n = 71; angiographically normal coronary arteries, n = 32) and investigated the correlations between the plasma levels of serotonin and glycero-LPLs. The results revealed the existence of a specific and significant association between the plasma serotonin and plasma lysophosphatidylserine (LysoPS) levels. On the contrary, regular aspirin intake failed to affect the plasma LysoPS levels despite the fact that the plasma lysophosphatidic acid, lysophosphatidylethanolamine, lysophosphatidylglycerol, and lysophosphatidylinositol levels were lower in those who had taken aspirin regularly. Conclusion We found a specific positive correlation between the blood levels of serotonin and LysoPS, a new lipid mediator. Thus, LysoPS might be specifically involved in strong platelet activation, which is associated with the release of serotonin. General Significance Our present results suggest the possible involvement of LysoPS in the pathogenesis of atherosclerotic diseases.


Journal of Lipid Research | 2017

Different Origins of Lysophospholipid Mediators between Coronary and Peripheral Arteries in Acute Coronary Syndrome

Makoto Kurano; Kuniyuki Kano; Tomotaka Dohi; Hirotaka Matsumoto; Koji Igarashi; Masako Nishikawa; Ryunosuke Ohkawa; Hitoshi Ikeda; Katsumi Miyauchi; Hiroyuki Daida; Junken Aoki; Yutaka Yatomi

Lysophosphatidic acids (LysoPAs) and lysophosphatidylserine (LysoPS) are emerging lipid mediators proposed to be involved in the pathogenesis of acute coronary syndrome (ACS). In this study, we attempted to elucidate how LysoPA and LysoPS become elevated in ACS using human blood samples collected simultaneously from culprit coronary arteries and peripheral arteries in ACS subjects. We found that: 1) the plasma LysoPA, LysoPS, and lysophosphatidylglycerol levels were not different, while the lysophosphatidylcholine (LysoPC), lysophosphatidylinositol, and lysophosphatidylethanolamine (LysoPE) levels were significantly lower in the culprit coronary arteries; 2) the serum autotaxin (ATX) level was lower and the serum phosphatidylserine-specific phospholipase A1 (PS-PLA1) level was higher in the culprit coronary arteries; 3) the LysoPE and ATX levels were significant explanatory factors for the mainly elevated species of LysoPA, except for 22:6 LysoPA, in the peripheral arteries, while the LysoPC and LysoPE levels, but not the ATX level, were explanatory factors in the culprit coronary arteries; and 4) 18:0 and 18:1 LysoPS were significantly correlated with PS-PLA1 only in the culprit coronary arteries. In conclusion, the origins of LysoPA and LysoPS might differ between culprit coronary arteries and peripheral arteries, and substrates for ATX, such as LysoPC and LysoPE, might be important for the generation of LysoPA in ACS.


Journal of Atherosclerosis and Thrombosis | 2017

Vehicle-dependent Effects of Sphingosine 1-phosphate on Plasminogen Activator Inhibitor-1 Expression

Chiharu Takahashi; Makoto Kurano; Masako Nishikawa; Kuniyuki Kano; Tomotaka Dohi; Katsumi Miyauchi; Hiroyuki Daida; Tomo Shimizu; Junken Aoki; Yutaka Yatomi

Aim: Sphingosine 1-phosphate (S1P) has been suggested to be a positive regulator of plasminogen activator inhibitor 1 (PAI-1) in adipocytes, while some studies are not consistent with this prothrombotic property of S1P. Since S1P is bound to apolipoprotein M (apoM) on HDL or to albumin in plasma, we compared the properties of these two forms on the PAI-1 induction. Methods: We investigated the associations of S1P, apoM, and PAI-1 concentrations in the plasma of normal coronary artery (NCA), stable angina pectoris (SAP), and acute coronary syndrome (ACS) subjects (n = 32, 71, and 38, respectively). Then, we compared the effects of S1P with various vehicles on the PAI-1 expression in 3T3L1 adipocytes. We also investigated the modulation of the PAI-1 levels in mice infected with adenovirus coding apoM. Results: Among ACS subjects, the PAI-1 level was positively correlated with the S1P level, but not the apoM level. In adipocytes, S1P bound to an apoM-rich vehicle induced PAI-1 expression to a lesser extent than the control vehicle, while S1P bound to an apoM-depleted vehicle induced PAI-1 expression to a greater extent than the control vehicle in 3T3L1 adipocytes. Additionally, apoM overexpression in mice failed to modulate the plasma PAI-1 level and the adipose PAI-1 expression level. S1P bound to albumin increased PAI-1 expression through the S1P receptor 2-Rho/ROCK-NFκB pathway. Conclusion: S1P bound to albumin, but not to apoM, induces PAI-1 expression in adipocytes, indicating that S1P can exert different properties on the pathogenesis of vascular diseases, depending on its vehicle.


Journal of Lipid Research | 2017

Analysis of glycero-lysophospholipids in gastric cancerous ascites

Shigenobu Emoto; Makoto Kurano; Kuniyuki Kano; Keisuke Matsusaki; Hiroharu Yamashita; Masako Nishikawa; Koji Igarashi; Hitoshi Ikeda; Junken Aoki; Joji Kitayama; Yutaka Yatomi

Lysophosphatidic acid (LysoPA) has been proposed to be involved in the pathogenesis of various cancers. Moreover, glycero-lysophospholipids (glycero-LysoPLs) other than LysoPA are now emerging as novel lipid mediators. Therefore, we aimed to elucidate the possible involvement of glycero-LysoPLs in the pathogenesis of gastric cancer by measuring glycero-LysoPLs, autotaxin (ATX), and phosphatidylserine-specific phospholipase A1 (PS-PLA1) in ascites obtained from patients with gastric cancer and those with cirrhosis (as a control). We observed that after adjustments according to the albumin levels, the lysophosphatidylserine (LysoPS) and lysophosphatidylglycerol (LysoPG) levels were significantly higher, while the LysoPA and ATX levels were lower, in the ascites from patients with gastric cancer. We also found that multiple regression analyses revealed that ATX was selected as a significant explanatory factor for all the detectable LysoPA species only in the cirrhosis group and that a significant positive correlation was observed between LysoPS and PS-PLA1 only in the gastric cancer group. In conclusion, the LysoPA levels might be determined largely by LysoPC and LysoPI (possible precursors) and the PS-PLA1-mediated pathway might be involved in the production of LysoPS in gastric cancer. Glycero-LysoPLs other than LysoPA might also be involved in the pathogenesis of cancer directly or through being converted into LysoPA.


Annals of Hematology | 2018

Eculizumab treatment for ischemic enteritis accompanied with paroxysmal nocturnal hemoglobinuria: a case report and literature review

Megumi Yasunaga; Kazuki Taoka; Hayato Nakagawa; Atsuo Yamada; Hiroyuki Abe; Masahiro Jona; Masako Nishikawa; Kumi Nakazaki; Yutaka Yatomi; Masashi Fukayama; Kazuhiko Koike; Mineo Kurokawa

Dear Editor, Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hematopoietic stem cell disease characterized by intravascular hemolysis by complement as a result of clonal expansion of hematopoietic stem cells having acquired mutations in PIG-A gene. PNH is known to cause deep venous thrombosis and this accounts for a large part of the causes of death in this disease [1, 2]. Ischemic enteritis accompanied with PNH was lifethreatening complications associated with extensive ischemia. We herein included a case report and literature review of treatments for ischemic enteritis with PNH. A 70-year-old female was diagnosed as PNH nine years ago. She had not received any treatment for a year before she began to receive 15 mg of prednisolone every other day due to the advent of hemolytic attacks. However, hemolytic attacks continued several times a year. Five years after the diagnosis, the patient had fever and hemolytic attacks; therefore, eculizumab was started instead of prednisolone. She came to our hospital complaining of right abdominal pain and fever one month later. Laboratory tests showed elevated C-reactive protein (7.02 mg/dl; normal < 0.30 mg/dl). Flow cytometry revealed the PNH defect in erythrocytes (CD55 and CD59 were deficient on 21%; normal 0–0.024%) and granulocytes (CD55 and CD59 were deficient on 90%; normal 0–0.008%). Prothrombin and activated partial thromboplastin times were within the normal ranges but fibrinogen (664 mg/dl; normal 186–355 mg/dl) and D-D dimer (12.9 μg/ml; normal < 0.9 μg/ml) were elevated. CT scan revealed the wall thickening as well as constriction of the ileum, and 10 cm stenotic lesion was detected by using a double-balloon endoscope. Then, partial ileectomy was performed for the severe ischemic enteritis, and the histopathology of the resected ileum showed shedding of mucosal membrane, dense inflammatory cell infiltration, and fibrosis (Fig. 1a, b). As eculizumab has been continuously administered once in two weeks, none of hemolytic attack and ischemic enteritis have recurred for four years. In this case, the patient with PNH had developed to contain ischemic enteritis in the course of repeated hemolytic attacks. * Mineo Kurokawa [email protected]


Circulation | 2013

Atorvastatin, Etidronate, or Both in Patients at High Risk for Atherosclerotic Aortic PlaquesClinical Perspective: A Randomized, Controlled Trial

Tetsuya Kawahara; Masako Nishikawa; Chie Kawahara; Tetsuya Inazu; Kunio Sakai; Gen Suzuki

Background— Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta. Methods and Results— A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, −16.4 to −11.3) and 12.3% (95% confidence interval, −14.9 to −9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, −0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (−11.4%) than in the atorvastatin group (−0.9%; P<0.001) and the etidronate group (5.5%; P=0.006). Conclusions— Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.


Circulation | 2013

Atorvastatin, Etidronate, or Both in Patients at High Risk for Atherosclerotic Aortic PlaquesClinical Perspective

Tetsuya Kawahara; Masako Nishikawa; Chie Kawahara; Tetsuya Inazu; Kunio Sakai; Gen Suzuki

Background— Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta. Methods and Results— A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, −16.4 to −11.3) and 12.3% (95% confidence interval, −14.9 to −9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, −0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (−11.4%) than in the atorvastatin group (−0.9%; P<0.001) and the etidronate group (5.5%; P=0.006). Conclusions— Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.


Circulation | 2013

Atorvastatin, Etidronate, or Both in Patients at High Risk for Atherosclerotic Aortic Plaques

Tetsuya Kawahara; Masako Nishikawa; Chie Kawahara; Tetsuya Inazu; Kunio Sakai; Gen Suzuki

Background— Statins are not effective in reducing atherosclerotic plaques of the abdominal aorta, and accumulating evidence suggests that bisphosphonates have the potential to induce the regression of atherosclerotic plaques of the abdominal aorta. Methods and Results— A prospective, randomized, open-label, blinded-end-point trial involving 108 participants with hypercholesterolemia was conducted. Participants received 20 mg atorvastatin daily, 400 mg etidronate daily, or both drugs daily. The primary end point was the percent change in maximal vessel wall thickness of atherosclerotic plaques in the thoracic and abdominal aortas as measured by magnetic resonance imaging after 12 months of treatment. In both the combination therapy and atorvastatin groups, maximal vessel wall thickness of the thoracic aorta was reduced by 13.8% (95% confidence interval, −16.4 to −11.3) and 12.3% (95% confidence interval, −14.9 to −9.7), respectively. These reduction rates were comparable between groups (P=0.61). Meanwhile, in the etidronate group, maximal vessel wall thickness of the thoracic aorta remained unchanged (2.2%; 95% confidence interval, −0.3 to 4.8). Conversely, maximal vessel wall thickness of the abdominal aorta was reduced more effectively in the combination therapy group (−11.4%) than in the atorvastatin group (−0.9%; P<0.001) and the etidronate group (5.5%; P=0.006). Conclusions— Atorvastatin plus etidronate combination therapy for 12 months significantly reduced both thoracic and abdominal aortic plaques, whereas atorvastatin monotherapy reduced only thoracic aortic plaques and etidronate monotherapy reduced only abdominal aortic plaques. The effectiveness of combination therapy in reducing atherosclerotic plaques in the abdominal aorta was significantly greater than for both atorvastatin and etidronate monotherapy. Clinical Trial Registration— URL: http://www.umin.ac.jp/ctr/. Unique identifier: UMIN 000002635.

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Chie Kawahara

University of Occupational and Environmental Health Japan

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Kunio Sakai

Ritsumeikan University

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