Faculty Profiles - IMAI Norihiro

Abdominal pain accompanied by elevated serum inflammatory markers and biliary enzymes for diagnosing immune checkpoint inhibitor-induced sclerosing cholangitis

Yamamoto, T; Mizuno, K; Ito, T; Yokoyama, S; Yamamoto, K; Imai, N; Ishizu, Y; Honda, T; Ishikawa, T; Kanamori, A; Yasuda, S; Toyoda, H; Yokota, K; Hase, T; Nishio, N; Maeda, O; Ishii, M; Sone, M; Ando, Y; Akiyama, M; Ishigami, M; Kawashima, H

INVESTIGATIONAL NEW DRUGS Vol. 41 ( 3 ) page： 512 - 521 2023.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Investigational New Drugs

Immune-related sclerosing cholangitis (irSC) is relatively rare and its clinical characteristics are not well known. In this study, we aimed to summarize the clinical features of irSC. Clinical data were collected retrospectively from 1,393 patients with advanced malignancy treated with immune-checkpoint inhibitors (ICIs) between August 2014 and October 2021. We analyzed patients with immune-related adverse events of liver injury (liver-irAEs) and compared irSC and non-irSC groups. Sixty-seven patients (4.8%) had a liver-irAE (≥ grade 3) during the follow-up period (median, 262 days). Among these, irSC was observed in eight patients (11.9%). All patients in the irSC group were treated with anti-PD-1/PD-L1 antibodies. Compared with the non-irSC group, the irSC group showed mainly non-hepatocellular liver injury (87.5 % vs 50.8 %, P = 0.065), and had elevated serum inflammatory markers (e.g., CRP and NLR) and biliary enzymes (e.g., GGTP and ALP) at the onset of liver-irAEs. Furthermore, most patients with irSC had abdominal pain. In the non-irSC group, the liver injury of 23 patients improved only with the discontinuation of ICIs, and 22 patients improved with medication including prednisolone (PSL). Conversely, almost all patients (n=7) in the irSC group were treated with PSL, but only two patients experienced an improvement in liver injury. We found that irSC is characterized by a non-hepatocellular type of liver injury with abdominal pain and a high inflammatory response and is refractory to treatment. Further examination by imaging is recommended to detect intractable irSC in cases with these characteristics.

DOI： 10.1007/s10637-023-01366-3

Significance of pretreatment alpha-fetoprotein in patients with compensated severe fibrosis after hepatitis C viral eradication

Ishigami, M; Honda, T; Ishizu, Y; Imai, N; Ito, T; Yamamoto, K; Kawashima, H

JOURNAL OF HEPATO-BILIARY-PANCREATIC SCIENCES Vol. 30 ( 6 ) page： 834 - 842 2023.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Hepato-Biliary-Pancreatic Sciences

Background: We aimed to investigate the factors associated with improvement of liver functional reserve after sustained virological response using interferon-free, direct-acting antiviral combination treatment in patients with compensated, severe fibrosis. Methods: Between September 2014 and April 2020, 492 patients received direct-acting antiviral combination treatment in our hospital. Among them, 173 patients who had severe fibrosis based on a fibrosis-4 index ≥3.25, showed sustained virological response after treatment. We investigated the dynamic change in albumin-bilirubin score and the baseline factors associated with its improvement, 48 weeks after treatment. Results: The baseline significant factors associated with albumin-bilirubin ≦ −0.5 were lower albumin (HR: 15.625, 95% CI: 4.273–58.824, P <.001), higher hepatitis C virus RNA (HR: 4.995, 95% CI: 1.882–13.260, P =.001), and higher alpha-fetoprotein (HR: 1.033, 95% CI: 1.011–1.055, P =.003). Patients with alpha-fetoprotein ≧10 ng/mL showed significant improvement of albumin-bilirubin score from baseline to 48 weeks after treatment compared to those with alpha-fetoprotein <10 ng/mL (P <.001). Conclusions: Baseline serum alpha-fetoprotein might be a predictive factor for improvement of liver function after sustained virological response in patients with severe fibrosis.

DOI： 10.1002/jhbp.1309

Distinct features of two lipid droplets types in cell nuclei from patients with liver diseases

Imai, N; Ohsaki, Y; Cheng, JL; Zhang, JJ; Mizuno, F; Tanaka, T; Yokoyama, S; Yamamoto, K; Ito, T; Ishizu, Y; Honda, T; Ishigami, M; Wake, H; Kawashima, H

SCIENTIFIC REPORTS Vol. 13 ( 1 ) page： 6851 2023.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Scientific Reports

Lipid droplets (LDs) have been observed in the nuclei of hepatocytes; however, their significance in liver disease remains unresolved. Our purpose was to explore the pathophysiological features of intranuclear LDs in liver diseases. We included 80 patients who underwent liver biopsies; the specimens were dissected and fixed for electron microscopy analysis. Depending on the presence of adjacent cytoplasmic invagination of the nuclear membrane, LDs in the nuclei were classified into two types: nucleoplasmic LDs (nLDs) and cytoplasmic LD invagination with nucleoplasmic reticulum (cLDs in NR). nLDs were found in 69% liver samples and cLDs in NR were found in 32%; no correlation was observed between the frequencies of the two LD types. nLDs were frequently found in hepatocytes of patients with nonalcoholic steatohepatitis, whereas cLDs in NR were absent from the livers of such patients. Further, cLDs in NR were often found in hepatocytes of patients with lower plasma cholesterol level. This indicates that nLDs do not directly reflect cytoplasmic lipid accumulation and that formation of cLDs in NR is inversely correlated to the secretion of very low-density lipoproteins. Positive correlations were found between the frequencies of nLDs and endoplasmic reticulum (ER) luminal expansion, suggesting that nLDs are formed in the nucleus upon ER stress. This study unveiled the presence of two distinct nuclear LDs in various liver diseases.

DOI： 10.1038/s41598-023-33977-4

A beta cell subset with enhanced insulin secretion and glucose metabolism is reduced in type 2 diabetes

Rubio-Navarro, A; Gómez-Banoy, N; Stoll, L; Dündar, F; Mawla, AM; Ma, LK; Cortada, E; Zumbo, P; Li, A; Reiterer, M; Montoya-Oviedo, N; Homan, EA; Imai, N; Gilani, A; Liu, CY; Naji, A; Yang, B; Chong, ACN; Cohen, DE; Chen, SB; Cao, JL; Pitt, GS; Huising, MO; Betel, D; Lo, JC

NATURE CELL BIOLOGY Vol. 25 ( 4 ) page： 565 - + 2023.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Nature Cell Biology

The pancreatic islets are composed of discrete hormone-producing cells that orchestrate systemic glucose homeostasis. Here we identify subsets of beta cells using a single-cell transcriptomic approach. One subset of beta cells marked by high CD63 expression is enriched for the expression of mitochondrial metabolism genes and exhibits higher mitochondrial respiration compared with CD63lo beta cells. Human and murine pseudo-islets derived from CD63hi beta cells demonstrate enhanced glucose-stimulated insulin secretion compared with pseudo-islets from CD63lo beta cells. We show that CD63hi beta cells are diminished in mouse models of and in humans with type 2 diabetes. Finally, transplantation of pseudo-islets generated from CD63hi but not CD63lo beta cells into diabetic mice restores glucose homeostasis. These findings suggest that loss of a specific subset of beta cells may lead to diabetes. Strategies to reconstitute or maintain CD63hi beta cells may represent a potential anti-diabetic therapy.

DOI： 10.1038/s41556-023-01103-1

Proteomic Analysis Reveals Changes in Tight Junctions in the Small Intestinal Epithelium of Mice Fed a High-Fat Diet

Muto, H; Honda, T; Tanaka, T; Yokoyama, S; Yamamoto, K; Ito, T; Imai, N; Ishizu, Y; Maeda, K; Ishikawa, T; Adachi, S; Sato, C; Tsuji, NM; Ishigami, M; Fujishiro, M; Kawashima, H

NUTRIENTS Vol. 15 ( 6 ) 2023.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Nutrients

The impact of a high-fat diet (HFD) on intestinal permeability has been well established. When bacteria and their metabolites from the intestinal tract flow into the portal vein, inflammation in the liver is triggered. However, the exact mechanism behind the development of a leaky gut caused by an HFD is unclear. In this study, we investigated the mechanism underlying the leaky gut related to an HFD. C57BL/6J mice were fed an HFD or control diet for 24 weeks, and their small intestine epithelial cells (IECs) were analyzed using deep quantitative proteomics. A significant increase in fat accumulation in the liver and a trend toward increased intestinal permeability were observed in the HFD group compared to the control group. Proteomics analysis of the upper small intestine epithelial cells identified 3684 proteins, of which 1032 were differentially expressed proteins (DEPs). Functional analysis of DEPs showed significant enrichment of proteins related to endocytosis, protein transport, and tight junctions (TJ). Expression of Cldn7 was inversely correlated with intestinal barrier function and strongly correlated with that of Epcam. This study will make important foundational contributions by providing a comprehensive depiction of protein expression in IECs affected by HFD, including an indication that the Epcam/Cldn7 complex plays a role in leaky gut.

DOI： 10.3390/nu15061473

Clustering using unsupervised machine learning to stratify the risk of immune-related liver injury

Yamamoto, T; Morooka, H; Ito, T; Ishigami, M; Mizuno, K; Yokoyama, S; Yamamoto, K; Imai, N; Ishizu, Y; Honda, T; Yokota, K; Hase, T; Maeda, O; Hashimoto, N; Ando, Y; Akiyama, M; Kawashima, H

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY Vol. 38 ( 2 ) page： 251 - 258 2023.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Gastroenterology and Hepatology (Australia)

Background and Aim: Immune-related liver injury (liver-irAE) is a clinical problem with a potentially poor prognosis. Methods: We retrospectively collected clinical data from patients treated with immune checkpoint inhibitors between September 2014 and December 2021 at the Nagoya University Hospital. Using an unsupervised machine learning method, the Gaussian mixture model, to divide the cohort into clusters based on inflammatory markers, we investigated the cumulative incidence of liver-irAEs in these clusters. Results: This study included a total of 702 patients. Among them, 492 (70.1%) patients were male, and the mean age was 66.6 years. During the mean follow-up period of 423 days, severe liver-irAEs (Common Terminology Criteria for Adverse Events grade ≥ 3) occurred in 43 patients. Patients were divided into five clusters (a, b, c, d, and e). The cumulative incidence of liver-irAE was higher in cluster c than in cluster a (hazard ratio [HR]: 13.59, 95% confidence interval [CI]: 1.70–108.76, P = 0.014), and overall survival was worse in clusters c and d than in cluster a (HR: 2.83, 95% CI: 1.77–4.50, P < 0.001; HR: 2.87, 95% CI: 1.47–5.60, P = 0.002, respectively). Clusters c and d were characterized by high temperature, C-reactive protein, platelets, and low albumin. However, there were differences in the prevalence of neutrophil count, neutrophil-to-lymphocyte ratio, and liver metastases between both clusters. Conclusions: The combined assessment of multiple markers and body temperature may help stratify high-risk groups for developing liver-irAE.

DOI： 10.1111/jgh.16038

Astaxanthin Attenuates Nonalcoholic Steatohepatitis with Downregulation of Osteoprotegerin in Ovariectomized Mice Fed Choline-Deficient High-Fat Diet

Zhao, M; Ma, LY; Honda, T; Kato, A; Ohshiro, T; Yokoyama, S; Yamamoto, K; Ito, T; Imai, N; Ishizu, Y; Nakamura, M; Kawashima, H; Tsuji, NM; Ishigami, M; Fujishiro, M

DIGESTIVE DISEASES AND SCIENCES Vol. 68 ( 1 ) page： 155 - 163 2023.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Digestive Diseases and Sciences

Background: Postmenopausal estrogen decline increases the risk of developing nonalcoholic steatohepatitis (NASH), and it might accelerate progression to cirrhosis and hepatocellular carcinoma. Aims: This study aimed to investigate a novel therapy for postmenopausal women who are diagnosed with NASH. Methods: Seven-week-old female C57BL/6 J mice were divided into three experimental groups as follows: (1) sham operation (SHAM group), (2) ovariectomy (OVX group), and (3) ovariectomy + 0.02% astaxanthin (OVX + ASTX group). These three groups of mice were fed a choline-deficient high-fat (CDHF) diet for 8 weeks. Blood serum and liver tissues were collected to examine liver injury, histological changes, and hepatic genes associated with NASH. An in vitro study was performed with the hepatic stellate cell line LX-2. Results: The administration of ASTX significantly improved pathological NASH with suppressed steatosis, inflammation, and fibrosis, in comparison with those in the OVX-induced estrogen deficiency group. As a result, liver injury was also attenuated with reduced levels of alanine aminotransferase and aspartate transaminase. In addition, our study found that ASTX supplementation decreased hepatic osteoprotegerin (OPG) in vivo, a possible factor that contributes to NASH development. In vitro, this study further confirmed that ASTX has an inhibitory effect on the secretion of OPG in LX-2 human hepatic stellate cells. Conclusions: Our findings suggest that ASTX alleviates CDHF-OVX-induced pathohistological NASH with downregulated OPG, possibly via suppression of the transforming growth factor beta pathway. ASTX could has promise for use in postmenopausal women diagnosed with NASH. Graphical Abstract: [Figure not available: see fulltext.].

DOI： 10.1007/s10620-022-07489-6

The presence of high-risk varices after sclerotherapy in biliary atresia

Yokoyama, S; Ishizu, Y; Honda, T; Imai, N; Ito, T; Yamamoto, K; Shirota, C; Tainaka, T; Sumida, W; Makita, S; Takimoto, A; Nakagawa, Y; Takada, S; Ishigami, M; Uchida, H; Kawashima, H

PEDIATRICS INTERNATIONAL Vol. 65 ( 1 ) page： e15454 2023.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Pediatrics International

Background: Esophagogastric varices (EGVs) may develop as a result of portal hypertension in children with biliary atresia (BA). Although endoscopic injection sclerotherapy (EIS) with ethanolamine oleate (EO) is reported useful for children, risk factors associated with the presence of high-risk EGVs after treatment remain unknown. Methods: The subjects were BA patients under 15 years of age who underwent EO-EIS. We retrospectively reviewed a total of 28 treatment sessions of EGVs with red signs and those larger than F2, which were considered to be at high risk of bleeding. Survival analysis was performed for the presence of high-risk EGVs at the time of follow-up endoscopy as the occurrence of an event. Results: Univariate analysis showed a significantly increased risk of the presence of high-risk EGVs post-EO-EIS in patients with increased liver stiffness (LS) and Mac-2 binding protein glycan isomer (M2BPGi), with hazard ratios of 1.48 and 1.15, respectively. The median presence-free period was significantly shorter in the LS ≥ 2.8 m/s patients than in those with LS <2.8 m/s (189 vs. 266 days). Similarly, the median presence-free period was significantly shorter in patients with M2BPGi ≥ 4.0 than in those with M2BPGi < 4.0 (182 vs. 203 days). The results of multivariate analysis revealed that the risk of the presence of high-risk EGVs was significantly higher only in the high-LS group, with a hazard ratio of 2.76. Conclusions: Increased LS is associated with risk of the presence of high-risk EGVs following EO-EIS in children with BA.

DOI： 10.1111/ped.15454

Differences in the Intestinal Microbiome Associated with Diarrhea during Lenvatinib Treatment for Hepatocellular Carcinoma

Inukai, Y; Yamamoto, K; Honda, T; Ito, T; Imai, N; Ishizu, Y; Nakamura, M; Kawashima, H; Ishigami, M

DIGESTIVE DISEASES Vol. 41 ( 1 ) page： 138 - 147 2023.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Digestive Diseases

Introduction: Lenvatinib has been widely used for the treatment of advanced hepatocellular carcinoma (HCC). Some adverse events, including diarrhea, have been reported for lenvatinib. Diarrhea may be associated with the changes in the intestinal microbiome; however, the underlying mechanism has not been elucidated. Aim: In this study, we aimed to investigate the relationship between the intestinal microbiome and diarrhea caused by lenvatinib via analysis of fecal samples collected before treatment. Methods: A total of 21 patients with advanced HCC who were treated with lenvatinib were enrolled. Fecal samples were collected from patients. The patients were divided into diarrhea (n = 8) and nondiarrhea groups (n = 12). We compared the characteristics of patients, incidence of adverse events, composition of the intestinal microbiome, and enrichment of functional pathways between both groups using QIIME2 and PICRUSt2. Results: The median age of the two groups was 73 years. The nondiarrhea group comprised a relatively higher number of male patients than the diarrhea group; however, there were no significant differences in patient characteristics between both groups. The proportion of the microbiome was similar, and alpha and beta diversities were not significantly different between both groups. The relative abundance of order Bacteroidales, including Parabacteroides and Prevotella, was higher in the diarrhea group than in the nondiarrhea group. PICRUSt2 analysis showed some metabolic pathways, including butanoate (butyrate) metabolism, were enriched in the nondiarrhea group when compared with those in the diarrhea group. Conclusion: Differences in the intestinal microbiomes and their functions may influence the incidence of diarrhea during lenvatinib treatment.

DOI： 10.1159/000524298

An improved method to assess skeletal muscle mass in patients with liver cirrhosis based on computed tomography images

Sugiyama, Y; Ishizu, Y; Ando, Y; Yokoyama, S; Yamamoto, K; Ito, T; Imai, N; Nakamura, M; Honda, T; Kawashima, H; Ishikawa, T; Ishigami, M

HEPATOLOGY RESEARCH Vol. 52 ( 11 ) page： 937 - 946 2022.11

Language：English Publishing type：Research paper (scientific journal) Publisher：Hepatology Research

Aim: Conventionally, the skeletal muscle area with computed tomography (CT) attenuation ranging from −29 to +150 Hounsfield unit (HU) divided by height squared (the conventional skeletal muscle index [SMI]) was used as an index of skeletal muscle mass. However, it includes fat-infiltrated skeletal muscle, which is known to have poor function. This study aims to determine whether the low-fat SMI, which uses skeletal muscle mass with CT attenuation ranging from +30 to +150 HU, or conventional SMI appropriately reflects the function of skeletal muscle. Methods: We retrospectively analyzed 120 patients with cirrhosis whose handgrip strength was measured. Among them, 48 patients underwent a physical performance assessment such as liver frailty index (LFI) and short physical performance battery (SPPB), and 80 underwent quality of life (QOL) assessment. The relationships between each SMI and handgrip strength, LFI, SPPB, and QOL were evaluated. Results: Low-fat SMI was significantly correlated with handgrip strength (males, R = 0.393, p = 0.002; females, R = 0.423, p < 0.001) and LFI (males, R = −0.535, p = 0.035; females, R = −0.368, p = 0.039), whereas conventional SMI was not. When using low-fat SMI, patients with low skeletal muscle mass had significantly low handgrip strength, LFI, SPPB, and physical and social-related QOL score than those without. By contrast, no significant differences were found for any items when using conventional SMI. Conclusions: Low-fat SMI is a good index of skeletal muscle mass that appropriately reflects skeletal muscle function.

DOI： 10.1111/hepr.13820

ANOREXIA IS ASSOCIATED WITH THE PRESENCE OF SARCOPENIA IN PATIENTS WITH CIRRHOSIS

Ishizu, Y; Yokoyama, S; Yamamoto, K; Ito, T; Imai, N; Honda, TH; Ishigami, M; Kawashima, H

HEPATOLOGY Vol. 76 page： S1181 - S1181 2022.10

USEFULNESS OF MUTATIONS INDUCED IN THE CORE REGION BY INTERFERON-BASED THERAPY

Honda, TH; Ishigami, M; Kato, A; Yokoyama, S; Yamamoto, K; Ito, T; Imai, N; Ishizu, Y; Yasuda, S; Toyoda, H; Kumada, T; Ishikawa, T; Kawashima, H

HEPATOLOGY Vol. 76 page： S262 - S263 2022.10

CLINICAL COURSE AND PROGNOSIS OF HEPATOCELLULAR CARCINOMA IN PATIENTS WITH HEMOPHILIA

Imai, N; Ishigami, M; Matsuda, N; Yokoyama, S; Yamamoto, K; Ito, T; Ishizu, Y; Honda, TH; Kawashima, H

HEPATOLOGY Vol. 76 page： S1330 - S1330 2022.10

Changes in Body Composition Predict the Time to Treatment Failure of Lenvatinib in Patients with Advanced Hepatocellular Carcinoma: A Pilot Retrospective Study.

Yamamoto T, Imai N, Kuzuya T, Yokoyama S, Yamamoto K, Ito T, Ishizu Y, Honda T, Ishigami M

Nutrition and cancer page： 1 - 10 2022.3

Patients with low muscle mass have characteristic microbiome with low potential for amino acid synthesis in chronic liver disease.

Yamamoto K, Ishizu Y, Honda T, Ito T, Imai N, Nakamura M, Kawashima H, Kitaura Y, Ishigami M, Fujishiro M

Scientific reports Vol. 12 ( 1 ) page： 3674 2022.3

Obesity and myosteatosis: the two characteristics of dynapenia in patients with cirrhosis.

Sugiyama Y, Ishizu Y, Ando Y, Yokoyama S, Yamamoto K, Ito T, Imai N, Nakamura M, Honda T, Kawashima H, Ishikawa T, Ishigami M

European journal of gastroenterology & hepatology Vol. 33 ( 1S Suppl 1 ) page： e916 - e921 2021.12

Language：English Publishing type：Research paper (scientific journal) Publisher：European journal of gastroenterology & hepatology

OBJECTIVE: In patients with liver cirrhosis, the clinical characteristics of dynapenia, a condition in which skeletal muscle mass is maintained but muscle strength is reduced, are not yet known. This study aimed to clarify the characteristics of dynapenia and its impact on quality of life (QOL) in patients with liver cirrhosis. METHODS: We retrospectively analyzed 116 patients with cirrhosis. Based on grip strength and skeletal muscle mass measured by the bioelectrical impedance analysis method, patients were divided into four groups: normal muscle status, dynapenia, pre-sarcopenia (a condition involving only low muscle mass), and sarcopenia. The characteristics of dynapenia and its influence on QOL were examined. RESULTS: Fourteen patients had dynapenia. Liver function did not differ among the four groups. In patients with dynapenia, BMI was highest and computed tomography attenuation of skeletal muscle at the third lumbar spine vertebra was lowest among the four groups. The percentage of patients with both BMI ≥25 kg/m2 and myosteatosis was significantly higher in patients with dynapenia [9/14 (64.3%)] than in those with sarcopenia [2/23 (8.7%), P = 0.004] and pre-sarcopenia [0/18 (0%), P < 0.001] and tended to be higher than those with normal muscle status [16/61 (26.2%), P = 0.065]. The physical QOL in patients with dynapenia was as low as that in those with sarcopenia and significantly lower than that in those with normal muscle status. CONCLUSION: Cirrhotic patients with dynapenia had high BMI and myosteatosis, and impaired physical QOL.

DOI： 10.1097/MEG.0000000000002303