Takaaki Sugihara

Dr. Takaaki Sugihara

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Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

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

Representative Publications

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KHKohshiro Hosokawa
Kohshiro Hosokawa
TTTomoaki TAKATA
Tomoaki TAKATA
TSTakaaki Sugihara
Takaaki Sugihara
TMTomomitsu Matono
Tomomitsu Matono
MKMasahiko Koda
Masahiko Koda
Hajime IsomotoHajime Isomoto
Hajime Isomoto
Background: Chronic kidney disease (CKD) and non-alcoholic steatohepatitis (NASH) are major health burdens closely related to metabolic syndrome. A link between CKD and NASH has been assumed; however, the underlying mechanism is still unknown. Ectopic lipid deposition (ELD) in the hepatocyte results in endoplasmic reticulum (ER) stress, which plays an important role in the development of steatohepatitis. ELD is also assumed to play a role in the development of kidney injury. We aimed to investigate the role of ELD and ER stress in the development of CKD, and evaluate the efficacy of a sodium glucose cotransporter-2 inhibitor, ipragliflozin. Methods: Male FLS-ob/ob mice that closely imitate the pathophysiology of NASH were treated with vehicle or ipragliflozin. Metabolic characteristics, histology of the kidney, ER stress, and apoptotic signals were evaluated. Results: The serum triglyceride was significantly lower in mice treated with ipragliflozin. Ipragliflozin reduced ELD in renal tubules. Ipragliflozin also reduced the expression levels of GRP78 and CHOP, apoptotic cells, and interstitial fibrosis. Conclusions: ELD induced kidney injury through ER stress. Ipragliflozin improved the pathogenesis of CKD by reducing ELD and ER stress in NASH-model mice. Our results suggest ipragliflozin has therapeutic effect on CKD in NASH.

27 February 2020 in PLOS ONE
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KOKinya Okamoto
Kinya Okamoto
MKMasahiko Koda
Masahiko Koda
TOToshiaki Okamoto
Toshiaki Okamoto
TOTakumi Onoyama
Takumi Onoyama
KMKenichi Miyoshi
Kenichi Miyoshi
HIHajime Isomoto
Hajime Isomoto
Non-alcoholic fatty liver disease (NAFLD) has a wide spectrum, eventually leading to cirrhosis and hepatic carcinogenesis. We previously reported that a series of microRNAs (miRNAs) mapped in the 14q32.2 maternally imprinted gene region (Dlk1-Dio3 mat) are related to NAFLD development and progression in a mouse model. We examined the suitability of miR-379, a circulating Dlk1-Dio3 mat miRNA, as a human NAFLD biomarker. Eighty NAFLD patients were recruited for this study. miR-379 was selected from the putative Dlk1-Dio3 mat miRNA cluster because it exhibited the greatest expression difference between NAFLD and non-alcoholic steatohepatitis in our preliminary study. Real-time PCR was used to examine the expression levels of miR-379 and miR-16 as an internal control. One patient was excluded due to low RT-PCR signal. Compared to normal controls, serum miR-379 expression was significantly up-regulated in NAFLD patients. Receiver operating characteristic curve analysis suggested that miR-379 is a suitable marker for discriminating NAFLD patients from controls, with an area under the curve value of 0.72. Serum miR-379 exhibited positive correlations with alkaline phosphatase, total cholesterol, low-density-lipoprotein cholesterol and non-high-density-lipoprotein cholesterol levels in patients with early stage NAFLD (Brunt fibrosis stage 0 to 1). The correlation between serum miR-379 and cholesterol levels was lost in early stage NAFLD patients treated with statins. Software-based predictions indicated that various energy metabolism–related genes, including insulin-like growth factor-1 (IGF-1) and IGF-1 receptor, are potential targets of miR-379. Serum miR-379 exhibits high potential as a biomarker for NAFLD. miR-379 appears to increase cholesterol lipotoxicity, leading to the development and progression of NAFLD, via interference with the expression of target genes, including those related to the IGF-1 signaling pathway. Our results could facilitate future research into the pathogenesis, diagnosis, and treatment of NAFLD.

1 January 2020 in Yonago Acta Medica
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SISuguru Ikeda
Suguru Ikeda
TSTakaaki Sugihara
Takaaki Sugihara
YHYoshiki Hoshino
Yoshiki Hoshino
YMYukako Matsuki
Yukako Matsuki
TNTakakazu Nagahara
Takakazu Nagahara
HIHajime Isomoto
Hajime Isomoto
Background Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease related to metabolic syndrome, which can progress to liver cirrhosis. Standard medication has not been established. Pemafibrate is a selective peroxisome proliferator-activated receptor (PPAR) α modulator. We retrospectively evaluated the efficacy of pemafibrate in patients with NAFLD.Methods We retrospectively enrolled 17 patients (ten men, seven women; median age, 63 years; range, 27–81 years). They were all proven to have fatty liver through imaging and had little or no history of drinking (ethanol consumption of < 20 g/day for women and < 30 g/day for men). They were administered pemafibrate from October 2018 to June 2020.Results After administration, serum triglyceride (TG) tended to be decreased (300.5 ± 22.5 to 239.5 ± 34.3 mg/dL, P = 0.06). Serum high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol levels did not change. ALT was significantly decreased (–47.4%) for six months (57.5 ± 8.8 to 30.3 ± 5.8 U/L, P < 0.01). The values of serum GGT significantly decreased (–48.7%) for sixth months (63.9 ± 10.3 to 32.8 ± 6.6 U/L, P < 0.01). Aspartate aminotransferase (AST) to platelet ratio (APRI), a fibrosis marker, also was significantly decreased in the sixth month (0.7 ± 0.1 to 0.4 ± 0.1, P < 0.05). Body mass index (BMI) and hemoglobin A1c (HbA1c) showed no significant change.Conclusion Pemafibrate dramatically ameliorated the values of liver function tests and APRI in patients with NAFLD.

7 December 2018 in Journal of Clinical Medicine
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SHShotaro Hoi
Shotaro Hoi
TTTomoaki TAKATA
Tomoaki TAKATA
TSTakaaki Sugihara
Takaaki Sugihara
AIAyami Ida
Ayami Ida
MOMasaya Ogawa
Masaya Ogawa
Hajime IsomotoHajime Isomoto
Hajime Isomoto
Background: Kidney size is associated with renal function, however it is not elucidated whether kidney size is a risk for the progression of chronic kidney disease. The aim of this study was to investigate the predictive value of morphological evaluation of kidney size by ultrasonography for the progression of renal dysfunction. Methods: Morphological parameters including kidney length, volume, cortical thickness, and medullary thickness were measured by ultrasonography in 87 patients with chronic kidney disease, and adjusted by body size. Renal functions at baseline and after 2 years were measured and the associations of morphological parameters to decline in renal function over 2 years were analyzed. Results: Height-adjusted cortical thickness was correlated to decline in renal function (r = 0.426, p < 0.001). Height-adjusted cortical thickness could predict renal dysfunction with the area under the curve of 0.786, and height-adjusted cortical thickness of 4.0 mm/cm was a cut off value with a sensitivity of 72.5% and a specificity of 80.0% for the risk of a more than 30% decline in renal function or initiation of dialysis. Conclusions: We provide new insights into the utility of measuring cortical thickness by ultrasonography for predict future renal impairment.

9 December 2021 in Diagnostics
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SISuguru Ikeda
Suguru Ikeda
TSTakaaki Sugihara
Takaaki Sugihara
TKTakuya Kihara
Takuya Kihara
YMYukako Matsuki
Yukako Matsuki
TNTakakazu Nagahara
Takakazu Nagahara
Hajime IsomotoHajime Isomoto
Hajime Isomoto
Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease related to metabolic syndrome. No standard pharmacological treatment has yet been established. We retrospectively evaluated the efficacy of pemafibrate in 16 NAFLD patients (11 men and 5 women; median age, 59 years; range, 27–81 years) who had taken pemafibrate for at least one year. They were all diagnosed with fatty liver according to imaging and clinical criteria. They were administered pemafibrate from October 2018 to October 2021 (median, 94 weeks; range, 56–157 weeks). Serum triglyceride was significantly decreased by −41.9% (342.3 ± 54.0 to 198.9 ± 20.4 mg/dL, p < 0.001). Aspartate aminotransferase (AST), alanine aminotransferase, and gamma-glutamyl transferase levels significantly decreased by −42.1% (49.6 ± 7.0 to 28.7 ± 3.4 U/L, p < 0.001), −57.1% (65.1 ± 10.8 to 27.9 ± 3.7 U/L, p < 0.001), and −43.2% (68.9 ± 10.9 to 39.1 ± 5.3 U/L, p < 0.05), respectively. The AST to platelet ratio (APRI) (0.8 ± 0.1 to 0.4 ± 0.1, p < 0.001) and fibrosis based on four factors (FIB-4) index (1.8 ± 0.3 to 1.4 ± 0.2, p < 0.05) also significantly decreased. Liver attenuation (39.1 ± 1.2 to 57.8 ± 2.7 HU, p = 0.028) and liver/spleen ratio (0.76 ± 0.04 to 1.18 ± 0.02, p = 0.012) significantly improved in three patients, as assessed by computed tomography. In conclusion, pemafibrate significantly improves serum triglyceride levels, liver function, FIB-4 index, APRI, and fatty liver in NAFLD patients with hypertriglyceridemia.

3 August 2021 in Oncology Letters
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HTHasegawa Takashi
Hasegawa Takashi
TSTakaaki Sugihara
Takaaki Sugihara
HYHoshino Yoshiki
Hoshino Yoshiki
TRTarumoto Ryohei
Tarumoto Ryohei
MYMatsuki Yukako
Matsuki Yukako
IHIsomoto Hajime
Isomoto Hajime
Yes‑associated protein (YAP) positivity indicates a poor prognosis in gastric cancer. Transcriptional co‑activator with a PDZ‑binding domain (TAZ), a YAP paralog, is highly expressed in gastric signet ring cell carcinoma. Verteporfin (VP), a clinical photosensitizer, was recently shown to inhibit YAP/TAZ. In the present study, the therapeutic potential of VP treatment was explored using two gastric cancer cell lines: MKN‑45 (TAZ‑dominant) and MKN‑74 (YAP‑dominant). Cell proliferation was evaluated by MTS assay. Vascular mimicry was evaluated by the tube formation assay. Gene and protein expression levels of YAP/TAZ downstream effectors [such as Survivin, Cysteine‑rich angiogenic inducer 61 (CYR61), and connective tissue growth factor (CTGF)] were measured. YAP or TAZ localization was evaluated by immunofluorescence. Cell death was assessed by immunofluorescent staining of Annexin V. YAP and TAZ expression were knocked down by small interfering RNA. The current results demonstrate that MKN‑45, a poorly differentiated TAZ‑dominant gastric cancer cell line, was more sensitive to VP than MKN‑74, a moderately differentiated YAP‑dominant gastric cancer cell line. VP changed the localization of YAP/TAZ, promoted its degradation and significantly decreased the protein level of Survivin in both cell lines. Cell death was induced by VP treatment in a dose‑dependent manner. Vascular mimicry was inhibited in both cell lines. Proliferation in both cell lines decreased in response to YAP/TAZ knockdown. The present study indicated that VP has potential as a therapeutic agent in YAP‑ and TAZ‑dominant gastric cancers due to its ability to suppress the anti‑apoptotic protein Survivin via inhibition of YAP and TAZ.