Koutaro Yokote

Koutaro Yokote


Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 February 2019 in Diabetes Care
Verified
Journal Article
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TDThomas Danne
Thomas Danne
SGSatish Garg
Satish Garg
APAnne L. Peters
Anne L. Peters
JBJohn B. Buse
John B. Buse
CMChantal Mathieu
Chantal Mathieu
MPMoshe Phillip
Moshe Phillip
Sodium–glucose cotransporter (SGLT) inhibitors are new oral antidiabetes medications shown to effectively reduce glycated hemoglobin (A1C) and glycemic variability, blood pressure, and body weight without intrinsic properties to cause hypoglycemia in people with type 1 diabetes. However, recent studies, particularly in individuals with type 1 diabetes, have demonstrated increases in the absolute risk of diabetic ketoacidosis (DKA). Some cases presented with near-normal blood glucose levels or mild hyperglycemia, complicating the recognition/diagnosis of DKA and potentially delaying treatment. Several SGLT inhibitors are currently under review by the U.S. Food and Drug Administration and European regulatory agencies as adjuncts to insulin therapy in people with type 1 diabetes. Strategies must be developed and disseminated to the medical community to mitigate the associated DKA risk. This Consensus Report reviews current data regarding SGLT inhibitor use and provides recommendations to enhance the safety of SGLT inhibitors in people with type 1 diabetes.

1 January 2024 in Endocrine Journal
Verified
Journal Article
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WOWataru Ogawa
Wataru Ogawa
YHYushi Hirota
Yushi Hirota
SMShigeru Miyazaki
Shigeru Miyazaki
TNTadashi Nakamura
Tadashi Nakamura
YOYoshihiro Ogawa
Yoshihiro Ogawa
O(on behalf of the Creation Committee for Guidelines for the Management of Obesity Disease 2022 by Japan Society for the Study of Obesity (JASSO)
on behalf of the Creation Committee for Guidelines for the Management of Obesity Disease 2022 by Japan Society for the Study of Obesity (JASSO)
To identify those who might benefit from weight reduction within a large population of obese individuals, Japan Society for the Study of Obesity (JASSO) advocated the concept of “obesity disease.” Here we summarize the definition, criteria, and core concepts for the management of obesity disease based on JASSO’s latest guideline. JASSO defines obesity as excessive fat storage in adipose tissue associated with a BMI of ≥25 kg/m2. The threshold BMI of obesity is low as compared to Western countries given that Japanese individuals tend to develop obesity-related health disorders at lower BMI. Obesity with a BMI of ≥35 kg/m2 is referred to as “high-degree obesity” as treatment strategies vary based on the degree of obesity. Obesity is diagnosed as “obesity disease” if accompanied by any of the 11 specific obesity-related health disorders that weight reduction can prevent or alleviate, or if it meets the criteria for visceral fat obesity with a visceral fat area of ≥100 cm2. The initial weight reduction goals for high-degree obesity disease range from 5% to 10% of their current body weight, depending on the associated health disorders. That for those with obesity disease who do not qualify as high-degree is 3% or more. If these initial goals are not achieved, intensifying dietary therapy or introducing drug therapy (or both) may be necessary. While surgical treatment is primarily indicated for high-degree obesity disease, it might be appropriate for cases of obesity disease with a BMI <35 kg/m2, depending on the accompanying health disorders. Enhancing the quality of life for individuals with obesity or obesity disease necessitates a broader societal approach, emphasizing the resolution of related stigma.

1 June 2016 in Atherosclerosis
Verified
Journal Article
Open access
SIShun Ishibashi
Shun Ishibashi
Shizuya YamashitaShizuya Yamashita
Shizuya Yamashita
HAHidenori Arai
Hidenori Arai
EAEiichi Araki
Eiichi Araki
KYKoutaro Yokote
Koutaro Yokote
TKTatsuhiko Kodama
Tatsuhiko Kodama
To assess the efficacy and safety of K-877 (Pemafibrate), a novel selective peroxisome proliferator-activated receptor α modulator (SPPARMα) that possesses unique PPARα activity and selectivity, compared with placebo and fenofibrate in dyslipidaemic patients with high triglyceride (TG) and low high-density lipoprotein cholesterol (HDL-C) levels. This study was a double blind, placebo-controlled, parallel-group 12-week clinical trial. The study randomized 224 patients to K-877 0.025, 0.05, 0.1, 0.2 mg BID, fenofibrate 100 mg QD, or placebo (1:1:1:1:1:1) groups. Least squares mean percent changes from the baseline TG levels were -30.9%, -36.4%, -42.6%, -42.7% for the K-877 0.025, 0.05, 0.1, 0.2 mg BID respectively (p < 0.001), which were greater than that of the fenofibrate 100 mg QD (-29.7%, p < 0.001) group. Statistically significant improvements from the baseline HDL-C, very-low-density lipoprotein cholesterol, chylomicron cholesterol, remnant lipoprotein cholesterol, apolipoprotein (apo) B (apoB), and apoC-III were also observed in the K-877 groups. The incidence of adverse events (AEs) in the K-877 groups (32.4-56.8%) was comparable to those in placebo (47.2%) and fenofibrate 100 mg QD (56.8%); adverse drug reactions (ADRs) in the K-877 groups (2.7-5.4%) were less than those in placebo (8.3%) and fenofibrate 100 mg QD (10.8%) groups. In dyslipidaemic patients with high TG and low HDL-C, K-877 improved TG, HDL-C, and other lipid parameters without increasing AEs or ADRs, compared to placebo and fenofibrate. K-877 can be expected to improve atherogenicity and to be a new beneficial treatment for dyslipidaemic patients.

11 July 2014 in Journal of Diabetes Investigation
Verified
Journal Article
Open access
PDF file
YMYoshiro Maezawa
Yoshiro Maezawa
MTMinoru Takemoto
Minoru Takemoto
KYKoutaro Yokote
Koutaro Yokote
Diabetic nephropathy is the major cause of end‐stage renal failure throughout the world in both developed and developing countries. Diabetes affects all cell types of the kidney, including endothelial cells, tubulointerstitial cells, podocytes and mesangial cells. During the past decade, the importance of podocyte injury in the formation and progression of diabetic nephropathy has been established and emphasized. However, recent findings provide additional perspectives on pathogenesis of diabetic nephropathy. Glomerular endothelial damage is already present in the normoalbuminuric stage of the disease when podocyte injury starts. Genetic targeting of mice that cause endothelial injury leads to accelerated diabetic nephropathy. Tubulointerstitial damage, previously considered to be a secondary effect of glomerular protein leakage, was shown to have a primary significance in the progression of diabetic nephropathy. Emerging evidence suggests that the glomerular filtration barrier and tubulointerstitial compartment is a composite, dynamic entity where any injury of one cell type spreads to other cell types, and leads to the dysfunction of the whole apparatus. Accumulation of novel knowledge would provide a better understanding of the pathogenesis of diabetic nephropathy, and might lead to a development of a new therapeutic strategy for the disease.

27 July 2022 in Cancer Research
Verified
Journal Article
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SSSawako Suzuki
Sawako Suzuki
DVDivya Venkatesh
Divya Venkatesh
HKHiroaki Kanda
Hiroaki Kanda
ANAkitoshi Nakayama
Akitoshi Nakayama
HHHiroyuki Hosokawa
Hiroyuki Hosokawa
CPCarol Prives
Carol Prives
Glutamine synthase 2 (GLS2) is a key regulator of glutaminolysis and has been previously implicated in activities consistent with tumor suppression. Here we generated Gls2 knockout (KO) mice that develop late-occurring B-cell lymphomas and hepatocellular carcinomas (HCC). Further, Gls2 KO mice subjected to the hepatocarcinogenic Stelic Animal Model (STAM) protocol produce larger HCC tumors than seen in wild-type (WT) mice. GLS2 has been shown to promote ferroptosis, a form of cell death characterized by iron-dependent accumulation of lipid peroxides. In line with this, GLS2 deficiency, either in cells derived from Gls2 KO mice or in human cancer cells depleted of GLS2, conferred significant resistance to ferroptosis. Mechanistically, GLS2, but not GLS1, increased lipid reactive oxygen species (ROS) production by facilitating the conversion of glutamate to α-ketoglutarate (αKG), thereby promoting ferroptosis. Ectopic expression of WT GLS2 in a human hepatic adenocarcinoma xenograft model significantly reduced tumor size; this effect was nullified by either expressing a catalytically inactive form of GLS2 or by blocking ferroptosis. Furthermore, analysis of cancer patient datasets supported a role for GLS2-mediated regulation of ferroptosis in human tumor suppression. These data suggest that GLS2 is a bona fide tumor suppressor and that its ability to favor ferroptosis by regulating glutaminolysis contributes to its tumor suppressive function. Significance: This study demonstrates that the key regulator of glutaminolysis, GLS2, can limit HCC in vivo by promoting ferroptosis through αKG-dependent lipid ROS, which in turn might lay the foundation for a novel therapeutic approach.

4 June 2019 in Cardiovascular Diabetology
Verified
Journal Article
Open access
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JFJean-Charles Fruchart
Jean-Charles Fruchart
RSRaul D Santos
Raul D Santos
CACarlos A. Aguilar-Salinas
Carlos A. Aguilar-Salinas
MAMasanori Aikawa
Masanori Aikawa
Khalid Al-RasadiKhalid Al-Rasadi
Khalid Al-Rasadi
PLPeter Libby
Peter Libby
In the era of precision medicine, treatments that target specific modifiable characteristics of high-risk patients have the potential to lower further the residual risk of atherosclerotic cardiovascular events. Correction of atherogenic dyslipidemia, however, remains a major unmet clinical need. Elevated plasma triglycerides, with or without low levels of high-density lipoprotein cholesterol (HDL-C), offer a key modifiable component of this common dyslipidemia, especially in insulin resistant conditions such as type 2 diabetes mellitus. The development of selective peroxisome proliferator-activated receptor alpha modulators (SPPARMα) offers an approach to address this treatment gap. This Joint Consensus Panel appraised evidence for the first SPPARMα agonist and concluded that this agent represents a novel therapeutic class, distinct from fibrates, based on pharmacological activity, and, importantly, a safe hepatic and renal profile. The ongoing PROMINENT cardiovascular outcomes trial is testing in 10,000 patients with type 2 diabetes mellitus, elevated triglycerides, and low levels of HDL-C whether treatment with this SPPARMα agonist safely reduces residual cardiovascular risk.