Takahiro Sasaki

Takahiro Sasaki

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Takahiro Sasaki

Division of Gastroenterology, Department of Internal Medicine, Asahikawa Medical University, Midorigaoka-Higashi 2-1-1-1, Asahikawa 078-8510, Hokkaido, Japan

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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16 July 2020 in Scientific Reports
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Journal Article
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TSTakahiro Sasaki
Takahiro Sasaki
MSMasamitsu Shimazawa
Masamitsu Shimazawa
HKHiromitsu Kanamori
Hiromitsu Kanamori
YYYoshihisa Yamada
Yoshihisa Yamada
ANAnri Nishinaka
Anri Nishinaka
HHHideaki Hara
Hideaki Hara
Progranulin is a secreted growth factor associated with multiple physiological functions in ischemic pathophysiology. However, it is still not fully understood how progranulin is involved in ischemic lesion and cardiac remodeling after myocardial infarction (MI). In this study, we investigated the effects of progranulin on myocardial ischemia and reperfusion injury. We investigated progranulin expression using Western blotting and immunostaining after permanent left coronary artery (LCA) occlusion in mice. Infarct size and the number of infiltrating neutrophils were measured 24 h after permanent LCA occlusion. Recombinant mouse progranulin was administered before LCA occlusion. In addition, we evaluated cardiac function using cardiac catheterization and echocardiography, and fibrosis size by Masson’s trichrome staining after myocardial ischemia/reperfusion in rabbits. Recombinant human progranulin was administered immediately after induction of reperfusion. Progranulin expression increased in the myocardial ischemic area 1, 3, and 5 days after permanent LCA occlusion in mice. The administration of recombinant mouse progranulin significantly attenuated infarct size and infiltrating neutrophils 24 h after permanent LCA occlusion in mice. We also found that administration of recombinant human progranulin ameliorated the deterioration of cardiac dysfunction and fibrosis after myocardial ischemia/reperfusion in rabbits. These findings suggest that progranulin may protect myocardial ischemia/reperfusion injury.

Verified
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KTKeitaro Takahashi
Keitaro Takahashi
MFMikihiro Fujiya
Mikihiro Fujiya
HKHiroaki Konishi
Hiroaki Konishi
YMYuki Murakami
Yuki Murakami
TITakuya Iwama
Takuya Iwama
TOToshikatsu Okumura
Toshikatsu Okumura
The oncogenic properties of heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) have been reported, although the tumor-promoting mechanism remains unclear. We herein report the mechanism underlying colorectal cancer cell progression mediated by hnRNP H1. The growth of colorectal cancer cells was suppressed by hnRNP H1 downregulation. A terminal deoxynucleotidyl transferase dUTP nick-end labeling assay revealed the anti-apoptotic effect of hnRNP H1 in colorectal cancer cells. An RNA immunoprecipitation assay revealed that hnRNP H1 bound to sphingosine-1-phosphate lyase 1 (SGPL1). Reverse transcription-polymerase chain reaction revealed the high expression of hnRNP H1 mRNA in colorectal cancer cells and Spearman’s rank correlation coefficient showed a strong positive correlation between hnRNP H1 mRNA and SGPL1 mRNA. An siRNA of hnRNP H1 decreased SGPL1 mRNA expression in colorectal cancer cells, but not in non-tumorous cells. These findings suggested that hnRNP H1 increased SGPL1 mRNA expression specifically in cancer cells through direct binding. Targeted knockdown of hnRNP H1 or SGPL1 with siRNAs upregulated p53 phosphorylation and p53-associated molecules, resulting in cell growth inhibition, while hnRNP H1 upregulated the mRNA of SGPL1 and inhibited p53 activation, thereby promoting tumor cell growth. This is a novel mechanism underlying colorectal cancer cell progression mediated by hnRNP H1–SGPL1 mRNA stabilization.

20 March 2019 in Molecules
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Journal Article
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KMKentaro Moriichi
Kentaro Moriichi
MFMikihiro Fujiya
Mikihiro Fujiya
YKYu Kobayashi
Yu Kobayashi
YMYuki Murakami
Yuki Murakami
TITakuya Iwama
Takuya Iwama
TOToshikatsu Okumura
Toshikatsu Okumura
Background: Autofluorescence imaging (AFI) is useful for diagnosing colon neoplasms, but what affects the AFI intensity remains unclear. This study investigated the association between AFI and the histological characteristics, aberrant methylation status, and aberrant expression in colon neoplasms. Methods: Fifty-three patients with colorectal neoplasms who underwent AFI were enrolled. The AFI intensity (F index) was compared with the pathological findings and gene alterations. The F index was calculated using an image analysis software program. The pathological findings were assessed by the tumor crypt density, cell densities, and N/C ratio. The aberrant methylation of p16, E-cadherin, Apc, Runx3, and hMLH1 genes was determined by a methylation-specific polymerase chain reaction. The aberrant expression of p53 and Ki-67 was evaluated by immunohistochemical staining. Results: An increased N/C ratio, the aberrant expression of p53, Ki-67, and the altered methylation of p16 went together with a lower F index. The other pathological findings and the methylation status showed no association with the F index. Conclusions: AFI reflects the nuclear enlargement of tumor cells, the cell proliferation ability, and the altered status of cell proliferation-related genes, indicating that AFI is a useful and practical method for predicting the dysplastic grade of tumor cells and cell proliferation.

14 July 2023 in Medicine
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Journal Article
Open access
YSYuya Sugiyama
Yuya Sugiyama
NUNobohiro Ueno
Nobohiro Ueno
STShion Tachibana
Shion Tachibana
YKYu Kobayashi
Yu Kobayashi
YMYuki Murakami
Yuki Murakami
MFMikihiro Fujiya
Mikihiro Fujiya
Rationale: Latent tuberculosis (TB) infection screening before inducing anti-tumor necrosis factor (anti-TNF) alpha agents is important to prevent TB reactivation. However, latent TB infection reactivation may still occur, and the ideal therapeutic strategy for patients with inflammatory bowel disease (IBD) who develop active TB infection has not been established. Vedolizumab (VDZ) has a good safety profile, with low incidence rates of serious infections. However, its safety in patients with latent TB infection reactivation associated with anti-TNF-alpha agents remains unknown. Patient concerns: A 21-year-old Vietnamese male patient presented to our hospital with hemorrhagic stool. He had no personal or family history of IBD or TB. Diagnoses: Colonoscopy revealed multiple longitudinal ulcers and a cobblestone appearance in the terminal ileum, as well as multiple small erosions and aphtha throughout the colon. Computed tomography revealed a right lung nodular lesion. Serological interferon-gamma release assay and several culture tests were all negative. Thus, he was diagnosed with ileocolonic Crohn’s disease (CD) without TB. Interventions: The intravenous anti-TNF-alpha agent administration with an immunomodulator was initiated. Outcomes: Computed tomography revealed nodular lesion expansion at the right lung, and serological interferon-gamma release assay was positive. He was diagnosed with latent TB infection reactivation. Anti-TNF-alpha agent with an immunomodulator was immediately discontinued, and anti-TB therapy was initiated. His endoscopic findings were still active, and VDZ was selected for maintenance therapy because VDZ has a favorable safety profile with low incidence rates of serious infections. Consequently, mucosal healing was achieved without active TB relapse. Lessons: This case report presented a patient in whom VDZ was continued as maintenance therapy without inducing TB relapse in a patient with CD who developed latent TB infection reactivation associated with anti-TNF-alpha agents and summarized the safety profile of VDZ for patients with IBD with active or latent TB infection. VDZ may be a safe option for induction and maintenance therapy in patients with CD, even in cases with latent TB infection reactivation.

1 January 2021 in Journal of Gastric Cancer
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Journal Article
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KTKeitaro Takahashi
Keitaro Takahashi
NUNobohiro Ueno
Nobohiro Ueno
TSTakahiro Sasaki
Takahiro Sasaki
YKYu Kobayashi
Yu Kobayashi
YSYuya Sugiyama
Yuya Sugiyama
MFMikihiro Fujiya
Mikihiro Fujiya
Takahashi K, et al. J Gastric Cancer. 2021 Mar;21(1):103-109. https://doi.org/10.5230/jgc.2021.21.e11

22 March 2022 in BMC Gastroenterology
Verified
Journal Article
Open access
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SKShin Kashima
Shin Kashima
KMKentaro Moriichi
Kentaro Moriichi
YKYu Kobayashi
Yu Kobayashi
YSYuya Sugiyama
Yuya Sugiyama
YMYuki Murakami
Yuki Murakami
MFMikihiro Fujiya
Mikihiro Fujiya
Background: Reconstruction surgery-associated stricture frequently occurs in patients with long-gap esophageal atresia (LGEA). While several endoscopic dilatation methods have been applied and would be desirable, endoscopic recanalization is very difficult in cases with complete esophageal closure. Surgical treatment has been performed for a severe stricture, which causes extensive damage to the infant. No reports have described successful endoscopic recanalization for complete closure due to scarring after surgery for LGEA. We herein report the case of successful endoscopic recanalization by single endoscopist in an LGEA patient with complete closure after reconstruction surgery. Case presentation: A seven-month-old boy with LGEA who received reconstruction surgery and gastrostomy immediately after birth presented to our unit due to vomiting and malnutrition. Contrast radiography and peroral endoscopy detected complete closure of the esophagus at the anastomotic site. After confirming the length of stricture as several millimeters, we punctured the center of the lumen with a 25-G puncture needle under fluoroscopy. An endoscope was then inserted via the gastrostomy and the puncture hole was detected at the center of the lumen. After passing the guidewire, endoscopic balloon dilation was performed three times, and the hole was sufficiently dilatated. Oral ingestion was feasible, and his nutritional condition was improved. Conclusions: To our knowledge, this is the first report to propose a less invasive endoscopic approach to recanalize a site of complete esophageal closure in a LGEA patient after reconstruction surgery by single endoscopist. Our endoscopic procedure using an ultrathin endoscope and puncture needle may be a therapeutic option for the treatment of patients with complete esophageal closure in a LGEA patient after reconstruction surgery.