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Abstract Background The precise role of capsule endoscopy in the diagnostic algorithm of obscure gastrointestinal bleeding has yet to be determined. Despite the higher diagnostic yield of capsule endoscopy, the actual impact on clinical outcome remains poorly defined. The aim of this study was to evaluate the follow-up results of patients with obscure gastrointestinal bleeding to determine which management strategies after capsule endoscopy reduced rebleeding. Methods All patients in whom the cause of obscure gastrointestinal bleeding was investigated between May 2004 and March 2007 were studied retrospectively. We evaluated the clinical outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy using the rebleeding rate as the primary outcome. Results Seventy-seven patients with obscure gastrointestinal bleeding underwent capsule endoscopy. Capsule endoscopy identified clinically significant findings that were thought to be the sources of obscure gastrointestinal bleeding in 58.4% of the patients. The overall rebleeding rate was 36.4%. The rebleeding rate was significantly higher among patients with insignificant findings than among those with significant findings (p = 0.036). Among the patients in whom capsule endoscopy produced significant findings, the rebleeding rate of the patients who underwent therapeutic interventions was significantly lower than that in those who did not undergo intervention (9.5% vs 40.0%, p = 0.046). Conclusion Follow-up and further aggressive interventions are necessary for patients with obscure gastrointestinal bleeding and significant capsule endoscopy findings to reduce the chance of rebleeding.

Background: The precise role of capsule endoscopy in the diagnostic algorithm of obscure gastrointestinal bleeding has yet to be determined. Despite the higher diagnostic yield of capsule endoscopy, the actual impact on clinical outcome remains poorly defined. The aim of this study was to evaluate the follow-up results of patients with obscure gastrointestinal bleeding to determine which management strategies after capsule endoscopy reduced rebleeding.Methods: All patients in whom the cause of obscure gastrointestinal bleeding was investigated between May 2004 and March 2007 were studied retrospectively. We evaluated the clinical outcome of patients with obscure gastrointestinal bleeding after capsule endoscopy using the rebleeding rate as the primary outcome.Results: Seventy-seven patients with obscure gastrointestinal bleeding underwent capsule endoscopy. Capsule endoscopy identified clinically significant findings that were thought to be the sources of obscure gastrointestinal bleeding in 58.4% of the patients. The overall rebleeding rate was 36.4%. The rebleeding rate was significantly higher among patients with insignificant findings than among those with significant findings (p = 0.036). Among the patients in whom capsule endoscopy produced significant findings, the rebleeding rate of the patients who underwent therapeutic interventions was significantly lower than that in those who did not undergo intervention (9.5% vs 40.0%, p = 0.046).Conclusion: Follow-up and further aggressive interventions are necessary for patients with obscure gastrointestinal bleeding and significant capsule endoscopy findings to reduce the chance of rebleeding. [ABSTRACT FROM AUTHOR]

Background: Globally, prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing, and there is an urgent need to develop innovative therapies that promote liver regeneration following hepatectomy for this disease. Surgical excision is a key therapeutic approach with curative potential for liver tumors. However, hepatic steatosis can lead to delayed liver regeneration and higher post-operative complication risk. Mesenchymal stem cells-conditioned medium (MSC-CM) is considered a rich source of paracrine factors that can repair tissues and restore function of damaged organs. Meanwhile, hydrogels have been widely recognized to load MSC secretome and achieve sustained release. This study aimed to evaluate the therapeutic effect of hydrogel-encapsulated MSC-CM on liver regeneration following partial hepatectomy (PHx) in a rodent model of diet-induced hepatic steatosis., Methods: Male Lewis rats were fed with a methionine and choline-deficient diet. After 3 weeks of feeding, PHx was performed and rats were randomly allocated into two groups that received hydrogel-encapsulated MSC-CM or vehicle via the intra-mesenteric space of the superior mesenteric vein (SMV)., Results: The regeneration of the remnant liver at 30 and 168 h after PHx was significantly accelerated, and the expressions of proliferating cell nuclear antigen were significantly enhanced in the MSC-CM group. MSC-CM treatment significantly increased hepatic ATP and β-hydroxybutyrate content at 168 h after PHx, indicating that MSC-CM fosters regeneration not only in volume but also in functionality. The number of each TUNEL- and cleaved caspase-3 positive nuclei in hepatocytes at 9 h after PHx were significantly decreased in the MSC-CM group, suggesting that MSC-CM suppressed apoptosis. MSC-CM increased serum immunoregulatory cytokine interleukin-10 and interleukin-13 at 30 h after PHx. Additionally, mitotic figures and cyclin D1 expression decreased and hepatocyte size increased in the MSC-CM group, implying that this mode of regeneration was mainly through cell hypertrophy rather than cell division., Conclusions: MSC-CM represents a novel therapeutic approach for patients with MASLD requiring PHx., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Segmental grafts from living donors have advantages over grafts from deceased donors when used for small intestine transplantation. However, storage time for small intestine grafts can be extremely short and optimal graft preservation conditions for short-term storage remain undetermined. Secreted factors from mesenchymal stem cells (MSCs) that allow direct activation of preserved small intestine grafts. Freshly excised Luc-Tg LEW rat tissues were incubated in preservation solutions containing MSC-conditioned medium (MSC-CM). Preserved Luc-Tg rat-derived grafts were then transplanted to wild-type recipients, after which survival, injury score, and tight junction protein expression were examined. Luminance for each graft was determined using in vivo imaging. The findings indicated that 30-100 and 3-10 kDa fractions of MSC-CM have superior activating effects for small intestine preservation. Expression of the tight-junction proteins claudin-3, and zonula occludens-1 preserved for 24 h in University of Wisconsin (UW) solution containing MSC-CM with 50-100 kDa, as shown by immunostaining, also indicated effectiveness. Reflecting the improved graft preservation, MSC-CM preloading of grafts increased survival rate from 0% to 87%. This is the first report of successful transplantation of small intestine grafts preserved for more than 24 h using a rodent model to evaluate graft preservation conditions that mimic clinical conditions., Competing Interests: Author MM was employed by the company Asteras. However, he is only involved in supporting small intestine transplants and has no relation to the company Astellas. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Teratani, Fujimoto, Sakuma, Kasahara, Maeda, Miki, Lefor, Sata and Kitayama.)

Background: Osteopenia is a well-known risk factor for survival in patients with hepatocellular carcinoma; however, it is unclear whether osteopenia can apply to both genders and how osteopenia is associated with cancer progression. The aim of this study was to elucidate whether osteopenia predicts reduced survival in regression models in both genders and whether osteopenia is associated with the pathological factors associated with reduced survival., Methods: This study included 188 consecutive patients who underwent hepatectomy. Bone mineral density was assessed using computed tomography (CT) scan images taken within 3 months before surgery. Non-contrast CT scan images at the level of the 11th thoracic vertebra were used. The cutoff value of osteopenia was calculated using a threshold value of 160 Hounsfield units. Overall survival (OS) curves and recurrence-free survival (RFS) were constructed using the Kaplan-Meier method, as was a log-rank test for survival. The hazard ratio and 95% confidence interval for overall survival were calculated using Cox's proportional hazard model., Results: In the regression analysis, age predicted bone mineral density. The association in females was greater than that in males. The OS and RFS of osteopenia patients were shorter than those for non-osteopenia patients. According to univariate and multivariate analyses, osteopenia was an independent risk factor for OS and RFS. The sole pathological factor associated with osteopenia was microvascular portal vein invasion., Conclusion: Models suggest that osteopenia may predict decreased OS and RFS in patients undergoing resection of hepatocellular carcinoma due to the mechanisms mediated via microvascular portal vein invasion.

Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD., (© 2024. The Author(s).)

It is important to assess the prognosis and intervene before and after surgery in patients with hepatocellular carcinoma. This study aims to elucidate the association of outcomes and residual liver function after hepatectomy. A total of 176 patients who underwent the initial resection for hepatocellular carcinoma between January 2011 and March 2021 at Jichi Medical University were included. Hepatic clearance of the remnant liver was measured using 99mTc-galactosyl serum albumin scintigraphy. The log-rank test was used to analyze survival using the Kaplan-Meier method. Hazard ratios (HR) and 95% confidence intervals (CI) for overall survival were calculated using Cox's proportional hazard model. In multivariate analysis, microvascular invasion, intraoperative blood loss, and hepatic clearance of the remnant liver were independently associated with overall survival. Hepatic clearance of the remnant liver was independently associated with recurrence free survival. This is the first report to show that lower residual liver function is associated with shorter survival in patients with hepatocellular carcinoma undergoing hepatectomy. Preoperative determination of remnant liver function may allow assessment of prognosis in patients planned to undergo resection of hepatocellular carcinoma. Preservation of liver functional reserve may be crucial for improved long-term outcomes after hepatectomy., (© 2023. Springer Nature Limited.)

Background/aims: Endoscopic ultrasound gallbladder drainage (EUS-GBD) is gaining attention as a treatment method for cholecystitis. However, only a few studies have assessed the outcomes of permanent stenting with EUS-GBD. Therefore, we evaluated the clinical outcomes of permanent stenting using EUS-GBD., Methods: This was a retrospective, single-center cohort study. The criteria for EUS-GBD at our institution are a high risk for surgery, inability to perform surgery owing to poor performance status, and inability to obtain consent for emergency surgery. EUS-GBD was performed using a 7-Fr double-pigtail plastic stent with a dilating device. The primary outcomes were the recurrence-free rate of cholecystitis and the late-stage complication-avoidance rate. Secondary outcomes were technical success, clinical success, and procedural adverse events., Results: A total of 41 patients were included in the analysis. The median follow-up period was 168 (range, 10-1,238) days. The recurrence-free and late-stage complication-avoidance rates during the follow-up period were 95% (38 cases) and 90% (36 cases), respectively. There were only two cases of cholecystitis recurrence during the study period., Conclusion: EUS-GBD using double-pigtail plastic stent was safe and effective with few complications, even in the long term, in patients with acute cholecystitis.

The intricate interplay between gut microbes and the onset of experimental autoimmune encephalomyelitis (EAE) remains poorly understood. Here, we uncover remarkable similarities between CD4 + T cells in the spinal cord and their counterparts in the small intestine. Furthermore, we unveil a synergistic relationship between the microbiota, particularly enriched with the tryptophan metabolism gene EC:1.13.11.11, and intestinal cells. This symbiotic collaboration results in the biosynthesis of kynurenic acid (KYNA), which modulates the recruitment and aggregation of GPR35-positive macrophages. Subsequently, a robust T helper 17 (Th17) immune response is activated, ultimately triggering the onset of EAE. Conversely, modulating the KYNA-mediated GPR35 signaling in Cx3cr1 + macrophages leads to a remarkable amelioration of EAE. These findings shed light on the crucial role of microbial-derived tryptophan metabolites in regulating immune responses within extraintestinal tissues., Competing Interests: Declaration of interests K.M. is an employee of Miyarisan Pharmaceutical. This study has partially supported the finance for the collaboration study from Miyarisan Pharmaceutical., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Intestinal intraepithelial lymphocytes (IELs) reside in the gut epithelial layer, where they help in maintaining intestinal homeostasis. Peripheral CD4 + T cells can develop into CD4 + CD8αα + IELs upon arrival at the gut epithelium via the lamina propria (LP). Although this specific differentiation of T cells is well established, the mechanisms preventing it from occurring in the LP remain unclear. Here, we show that chemokine receptor 9 (CCR9) expression is low in epithelial CD4 + CD8αα + IELs, but CCR9 deficiency results in CD4 + CD8αα + over-differentiation in both the epithelium and the LP. Single-cell RNA sequencing shows an enriched precursor cell cluster for CD4 + CD8αα + IELs in Ccr9 -/- mice. CD4 + T cells isolated from the epithelium of Ccr9 -/- mice also display increased expression of Cbfβ2, and the genomic occupancy modification of Cbfβ2 expression reveals its important function in CD4 + CD8αα + differentiation. These results implicate a link between CCR9 downregulation and Cbfb2 splicing upregulation to enhance CD4 + CD8αα + IEL differentiation., (© 2023. Springer Nature Limited.)

Background: Platelet (PLT) transfusion was the most practical way to increase patients' PLT counts before invasive hepatic procedures such as radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). A novel drug that raises the PLT count by acting on the thrombopoietin receptor has recently become available., Methods: Lusutrombopag 3 mg was administered daily for 7 days to patients who underwent RFA for liver tumors with low PLT counts (< 50,000 PLT µL - 1 ). We collected demographic data concerning the patients' liver function and PLT counts., Results: Lusutrombopag was administered to 91 patients, with a median age of 71 years (range 51-86). Forty-two patients had hepatitis C, 12 had hepatitis B, 21 had alcoholic liver disease, 11 had nonalcoholic steatohepatitis, and five had other diseases. The median Child-Pugh score was 7 (range 5-11). Thirty-seven patients had stage I tumors, 41 had Stage II, 12 had stage III, and one had stage IV. PLT count was elevated from 4.4 × 10 4  ± 1.4 × 10 4 to 8.6 × 10 4  ± 2.5 × 10 4 PLT µL - 1 . Lusutrombopag administration prevented PLT transfusions in 84/91 patients (92%). No patient had bleeding complications after RFA. One had portal thrombosis after lusutrombopag administration. Patients who achieved PLT counts of > 50,000 PLT µL - 1 had higher PLT counts before lusutrombopag administration. The degree of splenomegaly did not affect the rate of PLT count elevation. There was no specific adverse effect by administrating lusutrombopag for patients with PLT counts of around 50,000 µL - 1 but > 50,000 µL - 1 ., Conclusions: Lusutrombopag administration before RFA was effective and seemed to be relatively safe for hepatocellular carcinoma patients with low PLT counts., Trial Registration: This study was approved by Japanese Red Cross Medical Center Institutional Reseach Comittie (#862, 07/03/2016), and was registered in a publically accessible primary register (#UMIN000046629, registered date: 14/01/2022)., (© 2023. The Author(s).)

Primary sclerosing cholangitis (PSC) is characterized by progressive biliary inflammation and fibrosis. Although gut commensals are associated with PSC, their causative roles and therapeutic strategies remain elusive. Here we detect abundant Klebsiella pneumoniae (Kp) and Enterococcus gallinarum in fecal samples from 45 PSC patients, regardless of intestinal complications. Carriers of both pathogens exhibit high disease activity and poor clinical outcomes. Colonization of PSC-derived Kp in specific pathogen-free (SPF) hepatobiliary injury-prone mice enhances hepatic Th17 cell responses and exacerbates liver injury through bacterial translocation to mesenteric lymph nodes. We developed a lytic phage cocktail that targets PSC-derived Kp with a sustained suppressive effect in vitro. Oral administration of the phage cocktail lowers Kp levels in Kp-colonized germ-free mice and SPF mice, without off-target dysbiosis. Furthermore, we demonstrate that oral and intravenous phage administration successfully suppresses Kp levels and attenuates liver inflammation and disease severity in hepatobiliary injury-prone SPF mice. These results collectively suggest that using a lytic phage cocktail shows promise for targeting Kp in PSC., (© 2023. The Author(s).)

Background and Aim: This study aimed to compare the efficacy and safety of endoscopic ultrasound-guided gallbladder drainage and percutaneous transhepatic gallbladder drainage as a bridge to surgery in patients with acute cholecystitis unfit for urgent cholecystectomy., Methods: This retrospective study included 46 patients who underwent cholecystectomy following endoscopic ultrasound-guided gallbladder drainage (EUS-GBD) or percutaneous transhepatic gallbladder drainage (PTGBD) for acute cholecystitis in NTT Tokyo Medical Center. We surveyed 35 patients as the EUS-GBD group and 11 patients as the PTGBD group, and compared the rate of technical success of the cholecystectomy and periprocedural adverse events. A 7-F, 10-cm double pigtail plastic stent was used for ultrasound-guided gallbladder drainage., Results: The rate of technical success of cholecystectomy was 100% in both groups. Regarding postsurgical adverse events, no significant difference was noted between the two groups (EUS-GBD group, 11.4%, vs. PTGBD group, 9.0%; p = 0.472)., Conclusions: EUS-GBD as a BTS seems to be an alternative for patients with AC because it can ensure lower adverse events. On the other hand, there are two major limitations in this study--the sample size is small and there is a risk of selection bias.

Background & Aims: B-cell depletion therapy with an anti-CD20 is an effective treatment strategy for patients with refractory autoimmune hepatitis (AIH). However, the mechanisms underlying B-cell action are unclear., Methods: Herein, we used the adeno-associated virus IL-12 model, in which hepatic IL-12 expression triggers liver injuries characteristic of AIH. We also analysed the clinical samples of patients with AIH., Results: B-cell depletion using anti-CD20 or splenectomy was found to improve liver functions and decrease the cytotoxic CD8 + T-cell (cytotoxic T lymphocyte [CTL]) count in the liver. This improvement was reversed by the adoptive transfer of splenic B cells derived from AAV IL-12-treated mice to splenectomised mice as it caused the hepatic CTL count to increase. RNA-sequencing analysis identified IL-15 as a key factor in pathogenic B cells, which promotes CTL expansion and subsequent migration to the liver via the CXCL9/CXCR3 axis. Indeed, IL-15 neutralisation ameliorated hepatitis by suppressing splenic and hepatic CTLs in vivo . The close distribution of B220 + B cells and CD8 + T cells in the spleen of AIH mice suggested mutual interactions. Mechanistically, IFNγ and CD40L/CD40 signalling were indispensable for the expression of IL-15 in B cells, and in vitro co-culture experiments revealed that splenic CD40L + CD8 + T cells promoted IL-15 production in B cells, which led to CTL expansion. In patients with AIH, high serum IL-15 concentration and IL-15 + B-cell counts, positively correlating with serum alanine aminotransferase levels, support translation and potential therapeutic targeting in human AIH., Conclusions: This investigation elucidated the roles of IL-15-producing splenic B cells that occur in concert with pathogenic CD8 + T cells during the development of AIH., Impact and Implications: IL-15-producing B cells were shown to exacerbate experimental AIH via cytotoxic T lymphocyte expansion. CD40L + CD8 + T cells promoted IL-15 expression in B cells, indicating the mutual interaction of both cells. High serum IL-15 concentrations, IL-15 + B-cell counts, and CD40L + IL-15Rα + CD8 + T-cell counts were confirmed in the blood of patients with AIH., (© 2023 The Author(s).)

The fate of resolution of liver fibrosis after withdrawal of liver injury is still incompletely elucidated. Toll-like receptor 4 (TLR4) in tissue fibroblasts is pro-fibrogenic. After withdrawal of liver injury, we unexpectedly observed a significant delay of fibrosis resolution as TLR4 signaling was pharmacologically inhibited in vivo in two murine models. Single-cell transcriptome analysis of hepatic CD11b + cells, main producers of matrix metalloproteinases (MMPs), revealed a prominent cluster of restorative Tlr4 -expressing Ly6c2 -low myeloid cells. Delayed resolution after gut sterilization suggested its microbiome-dependent nature. Enrichment of a metabolic pathway linking to a significant increase of bile salt hydrolase-possessing family Erysipelotrichaceae during resolution. Farnesoid X receptor-stimulating secondary bile acids including 7-oxo-lithocholic acids upregulated MMP12 and TLR4 in myeloid cells in vitro . Fecal material transplant in germ-free mice confirmed phenotypical correlations in vivo . These findings highlight a pro-fibrolytic role of myeloid TLR4 signaling after injury withdrawal and may provide targets for anti-fibrotic therapy., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Background: The prognostic importance of osteopenia in patients with intrahepatic cholangiocarcinoma (ICC) undergoing hepatectomy is unclear. The aim of this study was to evaluate the impact of osteopenia on survival in patients with ICC., Methods: A total of 71 patients who underwent hepatectomy at Jichi Medical University between July 2008 and June 2022 were included in this study. Non-contrast computed tomography scan images at the eleventh thoracic vertebra were used to assess bone mineral density. The cutoff value was calculated using a threshold value of 160 Hounsfield units. Overall survival curves were made using the Kaplan-Meier method and the log-rank test was used to evaluate survival. The hazard ratio (HR) and 95% confidence interval (CI) for overall survival were calculated using Cox's proportional hazard model., Results: In multivariable analysis, osteopenia (HR 3.66, 95%CI 1.16-14.1, p = 0.0258) and the platelet-lymphocyte ratio (HR 6.26, 95%CI 2.27-15.9, p = 0.0008) were significant independent factors associated with overall survival. There were no significant independent prognostic factors for recurrence-free survival., Conclusions: Preoperative osteopenia is significantly associated with postoperative survival in patients with ICC undergoing hepatectomy.

Background & Aims: D-amino acids, the chiral counterparts of protein L-amino acids, were primarily produced and utilized by microbes, including those in the human gut. However, little was known about how orally administered or microbe-derived D-amino acids affected the gut microbial community or gut disease progression., Methods: The ratio of D- to L-amino acids was analyzed in feces and blood from patients with ulcerative colitis (UC) and healthy controls. Also, composition of microbe was analyzed from patients with UC. Mice were treated with D-amino acid in dextran sulfate sodium colitis model and liver cholangitis model., Results: The ratio of D- to L-amino acids was lower in the feces of patients with UC than that of healthy controls. Supplementation of D-amino acids ameliorated UC-related experimental colitis and liver cholangitis by inhibiting growth of Proteobacteria. Addition of D-alanine, a major building block for bacterial cell wall formation, to culture medium inhibited expression of the ftsZ gene required for cell fission in the Proteobacteria Escherichia coli and Klebsiella pneumoniae, thereby inhibiting growth. Overexpression of ftsZ restored growth of E. coli even when D-alanine was present. We found that D-alanine not only inhibited invasion of pathological K. pneumoniae into the host via pore formation in intestinal epithelial cells but also inhibited growth of E. coli and generation of antibiotic-resistant strains., Conclusions: D-amino acids might have potential for use in novel therapeutic approaches targeting Proteobacteria-associated dysbiosis and antibiotic-resistant bacterial diseases by means of their effects on the intestinal microbiota community., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The success of islet transplantation in both basic research and clinical settings has proven that cell therapy has the potential to cure diabetes. Islets intended for transplantation are inevitably subjected to damage from a number of sources, including ischemic injury during removal and delivery of the donor pancreas, enzymatic digestion during islet isolation, and reperfusion injury after transplantation in the recipient. Here, we found that protein factors secreted by porcine adipose-tissue mesenchymal stem cells (AT-MSCs) were capable of activating preserved porcine islets. A conditioned medium was prepared from the supernatant obtained by culturing porcine AT-MSCs for 2 days in serum-free medium. Islets were preserved at 4°C in University of Wisconsin solution during transportation and then incubated at 37°C in RPMI-1620 medium with fractions of various molecular weights prepared from the conditioned medium. After treatment with certain fractions of the AT-MSC secretions, the intracellular ATP levels of the activated islets had increased to over 160% of their initial values after 4 days of incubation. Our novel system may be able to restore the condition of isolated islets after transportation or preservation and may help to improve the long-term outcome of islet transplantation. Abbreviations: AT-MSC, adipose-tissue mesenchymal stem cell; Cas-3, caspase-3; DAPI, 4,6-diamidino-2-phenylindole; DTZ, dithizone; ES cell, embryonic stem cell; FITC, fluorescein isothiocyanate; IEQ, islet equivalent; INS, insulin; iPS cell, induced pluripotent stem cell; Luc-Tg rat, luciferase-transgenic rat; PCNA, proliferating cell nuclear antigen; PDX1, pancreatic and duodenal homeobox protein-1; UW, University of Wisconsin; ZO1, zona occludens 1.

Cytotoxic CD4 + T cells (CD4-CTLs) show the presence of cytolytic granules, which include the enzymes granzyme and perforin. The cells have a pathogenic and protective role in various diseases, including cancer, viral infection, and autoimmune disease. In mice, cytotoxic CD4 + T cells express CD8αα + and reside in the intestine (mouse CD4 + CTLs; mCD4-CTLs). The population of cytotoxic CD4 + T cells in the human intestine is currently unknown. Moreover, it is unclear how cytotoxic CD4 T cells change in patients with inflammatory bowel disease (IBD). Here, we aimed to identify cytotoxic CD4 + T cells in the human intestine and analyze the characteristics of the population in patients with IBD using single-cell RNA-seq (scRNA-seq). In CD4 + T cells, granzyme and perforin expression was high in humanMAIT (hMAIT) cells and hCD4 + CD8A + T cell cluster. Both CD4 and CD8A were expressed in hTreg, hMAIT, and hCD4 + CD8A + T cell clusters. Next we performed fast gene set enrichment analysis to identify cell populations that showed homology to mCD4CTLs. The analysis identified the hCD4 + CD8A + T cell cluster (hCTL-like population; hCD4-CTL) similar to mouse CTLs. The percentage of CD4 + CD8A + T cells among the total CD4 + T cells in the inflamed intestine of the patients with Crohn's disease was significantly reduced compared with that in the noninflamed intestine of the patients. In summary, we identified cytotoxic CD4 + CD8 + T cells in the small intestine of humans. The integration of the mouse and human sc-RNA-seq data analysis highlight an approach to identify human cell populations related to mouse cell populations, which may help determine the functional properties of several human cell populations in mice., Competing Interests: Author KM is an employee of Miyarisan Pharmaceutical Co. Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tanemoto, Sujino, Miyamoto, Moody, Yoshimatsu, Ando, Koya, Harada, Tojo, Ono, Hayashi, Takabayashi, Okabayashi, Teratani, Mikami, Nakamoto, Hosoe, Ogata, Hon, Shin and Kanai.)

Group 2 innate lymphoid cells (ILC2s) serve as frontline defenses against parasites. However, excluding helminth infections, it is poorly understood how ILC2s function in intestinal inflammation, including inflammatory bowel disease.   Here, we analyzed the global gene expression of ILC2s in healthy and colitic conditions and revealed that type I interferon (T1IFN)-stimulated genes were up-regulated in ILC2s in dextran sodium sulfate (DSS)-induced colitis. The enhancement of T1IFN signaling in ILC2s in DSS-induced colitis was correlated with the downregulation of cytokine production by ILC2s, such as interleukin-5. Blocking T1IFN signaling during colitis resulted in exaggeration of colitis in both wild-type and Rag2 -deficient mice. The exacerbation of colitis induced by neutralization of T1IFN signaling was accompanied by reduction of amphiregulin (AREG) in ILC2s and was partially rescued by exogenous AREG treatment. Collectively, these findings show the potential roles of T1IFN in ILC2s that contribute to colitis manifestation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Irie, Ishihara, Mizushima, Hatai, Hagihara, Takada, Tsunoda, Iwata, Matsubara, Yoshimatsu, Kiyohara, Taniki, Sujino, Takabayashi, Hosoe, Ogata, Teratani, Nakamoto, Mikami and Kanai.)

Plasmacytoid dendritic cells (pDCs) perform dual proinflammatory and immunosuppressive roles. We recently reported the potential of pDC therapy for treatment of intractable acute liver failure. However, establishment of efficient methods to deliver pDCs to the liver is essential for future clinical therapeutic applications. The present study demonstrates a higher abundance of liver and peripheral blood pDCs in mice lacking C-C motif chemokine receptor 9 (CCR9), a pDC gut-homing receptor, than in WT mice. Adoptive transfer of Ccr9-/- pDCs resulted in a higher efficiency of migration to the liver than WT pDCs did, while WT pDCs migrated efficiently to the original target organ, the small intestine. Further, Ccr9-/- pDCs consistently migrated efficiently to livers with concanavalin A-induced inflammation, and exerted a more effective immunosuppressive effect, resulting in better protection against acute liver inflammation than that demonstrated by WT pDCs. These findings highlight the therapeutic potential of the manipulation of the CCR9 axis as an approach to improve migration of immunosuppressive pDCs to the liver in order to exploit their beneficial effects in acute liver disease.

It has long been assumed that the nervous system exerts distinct effects on immune functions, given the large number of immune disorders that are affected by mental stress. In fact, many different immune cells have been shown to possess a wide variety of neurotransmitter receptors and receive signals from various neurotransmitters, including acetylcholine and noradrenaline. Compared with the findings on local neuroimmune interactions, limited experimental techniques have so far failed to capture a comprehensive overview of neuroimmune interactions between distant organs and the autonomic nervous system in vivo, and the molecular mechanisms underlying local immune regulation of the nervous system have long remained unclear. However, the recent rapid progress in genetic recombination, microscopy and single-cell analysis has deepened our understanding of the anatomical and physiological functions of peripheral nerves at each organ to which they belong. Furthermore, the development of optogenetic and chemogenetic methods has enabled the artificial modulation of specific neuronal activities, and there has been remarkable progress in elucidation of the interaction between nerves and immune cells in vivo, particularly in barrier organs such as the gastrointestinal tract, respiratory tract and skin. This review focuses on the immunoregulatory mechanisms governed by the autonomic nervous system and outlines the latest findings in the regulation of enteric and hepatic immunity by the nervous system., (© The Author(s) 2022. Published by Oxford University Press on behalf of The Japanese Society for Immunology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: The Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) is a specifically designed scoring system for children and has been translated into several languages. However, to date, no validated Japanese version of this scoring system is available., Purpose: To translate the HSS Pedi-FABS into Japanese and assess its reliability and validity., Study Design: Cohort study (diagnosis); Level of evidence, 2., Methods: The HSS Pedi-FABS was translated into Japanese and back-translated into English to confirm the appropriateness of the translation. A total of 764 children aged 9 to 15 years participated in the validation study. The participants answered the Japanese version of the HSS Pedi-FABS along with 2 other questionnaires in Japanese (the Physical Activity Questionnaire for Older Children [PAQ-C] and the physical activity questionnaire of the World Health Organization's Health Behavior in School-aged Children [HBSC PAQ]). At 1 month after the first assessment, the children answered the Japanese version of the HSS Pedi-FABS again. We evaluated reliability using the Cronbach alpha and the intraclass correlation coefficient. Validity was evaluated by quantifying floor and ceiling effects, correlations between the HSS Pedi-FABS and the PAQ-C, the HSS Pedi-FABS discrepancy between active and inactive groups divided by the HBSC PAQ, and correlation between the HSS Pedi-FABS and body mass index., Results: HSS Pedi-FABS scores were slightly but significantly higher in male participants (mean = 16.7) than in female participants (mean = 13.2). The Cronbach alpha coefficient was .90, and the intraclass correlation coefficient value was 0.90, indicating excellent internal consistency and test-retest reliability, respectively. No floor (2.6%) or ceiling effect (1.0%) was observed. The HSS Pedi-FABS was significantly correlated with the PAQ-C ( r = 0.70). The active group demonstrated a significantly higher score on the HSS Pedi-FABS (mean = 18.9) than did the inactive group (mean = 11.2). In terms of discriminative validity, the HSS Pedi-FABS was not correlated with body mass index ( r = -0.15)., Conclusion: The Japanese version of the HSS Pedi-FABS demonstrated appropriate reliability and validity, indicating that it is a useful tool to assess physical activity levels in Japanese children., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was supported by Pfizer Global Medical Grants (grant 43802135). AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2022.)

Mouse studies have reported anti-stress effects of Lactiplantibacillus plantarum SNK12 (SNK). Specifically, oral SNK administration increased mRNA levels of hippocampal neurotrophic factor and gamma-aminobutyric acid receptor in mice with sub-chronic mild stress-induced social defeat; moreover, it improved depressive behavior. We aimed to evaluate the efficacy of SNK ingestion against stress in healthy adults. We used the Uchida-Kraepelin test for the stress load, with a low-dose (50 mg/day), high-dose (150 mg/day), and placebo groups (dextrin). The primary outcome was the psychological evaluation as measured by the Profile of Mood States 2nd Edition (POMS2) using total mood disturbance (TMD) scores. The secondary outcomes were the score of each POMS2 item, salivary cortisol as a stress marker, and autonomic balance with the low frequency (LF)/ high frequency (HF) ratio. Compared with the placebo group, the SNK ingestion group showed significantly lower TMD scores. Additionally, compared with the placebo group, the high-dose group showed significantly lower scores for Tension-Anxiety and Confusion-Bewilderment, while the low-dose group showed significantly lower Anger-Hostility scores, salivary cortisol levels, and LF/HF scores. Our findings suggest that SNK ingestion could relieve stress (negative feelings, anxiety, tension, embarrassment, confusion, anger, and hostility) resulting from the temporary load caused by work and study.

Group 2 innate lymphoid cells (ILC2s) were identified in 2010 as a novel lymphocyte subset lacking antigen receptors, such as T-cell or B-cell receptors. ILC2s induce local immune responses characterized by producing type 2 cytokines and play essential roles for maintaining tissue homeostasis. ILC2s are distributed across various organs, including the intestine where immune cells are continuously exposed to external antigens. Followed by luminal antigen stimulation, intestinal epithelial cells produce alarmins, such as IL-25, IL-33, and thymic stromal lymphopoietin, and activate ILC2s to expand and produce cytokines. In the context of parasite infection, the tuft cell lining in the epithelium has been revealed as a dominant source of intestinal IL-25 and possesses the capability to regulate ILC2 homeostasis. Neuronal systems also regulate ILC2s through neuropeptides and neurotransmitters, and interact with ILC2s bidirectionally, a process termed "neuro-immune crosstalk". Activated ILC2s produce type 2 cytokines, which contribute to epithelial barrier function, clearance of luminal antigens and tissue repair, while ILC2s are also involved in chronic inflammation and tissue fibrosis. Recent studies have shed light on the contribution of ILC2s to inflammatory bowel diseases, mainly comprising ulcerative colitis and Crohn's disease, as defined by chronic immune activation and inflammation. Modern single-cell analysis techniques provide a tissue-specific picture of ILC2s and their roles in regulating homeostasis in each organ. Particularly, single-cell analysis helps our understanding of the uniqueness and commonness of ILC2s across tissues and opens the novel research area of ILC2 heterogeneity. ILC2s are classified into different phenotypes depending on tissue and phase of inflammation, mainly inflammatory and natural ILC2 cells. ILC2s can also switch phenotype to ILC1- or ILC3-like subsets. Hence, recent studies have revealed the heterogeneity and plasticity of ILC2, which indicate dynamicity of inflammation and the immune system. In this review, we describe the regulatory mechanisms, function, and pathological roles of ILC2s in the intestine., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sunaga, Tsunoda, Teratani, Mikami and Kanai.)

CD4 + Foxp3 + regulatory T cells (Tregs) are essential for homeostasis in the colon, but the mechanism by which local environmental cues determine the localization of colonic Tregs is unclear. Here, we administer indigo naturalis (IN), a nontoxic phytochemical aryl hydrocarbon receptor (AhR) agonist used for treating patients with ulcerative colitis (UC) in Asia, and we show that IN increases Helios + Tregs and MHC class II + epithelial cells (ECs) in the colon. Interactions between Tregs and MHC class II + ECs occur mainly near the crypt bottom in the steady state, whereas Tregs dramatically increase and shift toward the crypt top following IN treatment. Moreover, the number of CD25 + T cells is increased near the surface of ECs in IN-treated UC patients compared with that in patients treated with other therapies. We also highlight additional AhR-signaling mechanisms in intestinal ECs that determine the accumulation and localization of Helios + Tregs in the colon., Competing Interests: Declaration of interests K.M. and T.S. are employees of Miyarisan Pharmaceutical Co., Ltd., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Osteopenia is defined as low bone mineral density (BMD) and has been shown to be associated with outcomes of patients with various cancers. The association between osteopenia and perihilar cholangiocarcinoma is unknown. The aim of this study was to evaluate osteopenia as a prognostic factor in patients with perihilar cholangiocarcinoma. Methods: A total of 58 patients who underwent surgery for perihilar cholangiocarcinoma were retrospectively analyzed. The BMD at the 11th thoracic vertebra was measured using computed tomography scan within one month of surgery. Patients with a BMD < 160 HU were considered to have osteopenia and b BMD ≥ 160 did not have osteopenia. The log-rank test was performed for survival using the Kaplan−Meier method. After adjusting for confounding factors, overall survival was assessed by Cox′s proportional-hazards model. Results: The osteopenia group had 27 (47%) more females than the non-osteopenia group (p = 0.036). Median survival in the osteopenia group was 37 months and in the non-osteopenia group was 61 months (p = 0.034). In multivariable analysis, osteopenia was a significant independent risk factor associated with overall survival in patients with perihilar cholangiocarcinoma (hazard ratio 3.54, 95% confidence interval 1.09−11.54, p = 0.036), along with primary tumor stage. Conclusions: Osteopenia is associated with significantly shorter survival in patients with perihilar cholangiocarcinoma.

Surgical training using live animals such as pigs is one of the best ways of achieving skilled techniques and fostering confidence in preclinical medical students and surgeon trainees. However, due to animal welfare ethics, laboratory animals' usage for training should be kept to a minimum. We have developed a novel kidney organ model utilizing a simple procedure in which the kidney is first refluxed with N-vinyl-2-pyrrolidone (NVP) solution for 1 hour in its bath, followed by permeation for 23 hours, with a subsequent freshwater refluxed for 48 hours in the washing step. Surgical simulation of the prepared kidney model (NVP-fixed kidney) was compared with three types of other basic known simulation models (fresh kidney, freeze-thaw kidney, and FA-fixed kidney) by various evaluations. We found the NVP-fixed kidney to mimicked fresh kidney function the most, pertaining to the hardness, and strength of the renal parenchyma. Moreover, the NVP-fixed kidney demonstrated successful blood-like fluids perfusion and electrocautery. Further, we confirmed that surgical training could be performed under conditions closer to actual clinical practice. Our findings suggest that our model does not only contribute to improving surgical skills but also inspires the utilization of otherwise, discarded inedible livestock organs as models for surgical training., Competing Interests: The authors have declared that no competing interests exist.

The pathophysiology of inflammatory bowel diseases (IBDs) involves immunological, genetic and environmental factors. Through its ability to sense environmental stimuli, the autonomic nervous system plays a key role in the development and persistence of IBDs. The vagus nerve (VN), which contains sensory and motor neurons, travels throughout the body to innervate the gut and other visceral organs in the thoracic and abdominopelvic cavities. Recent studies show that the VN has anti-inflammatory effects via the release of acetylcholine, in what is known as the cholinergic anti-inflammatory pathway (CAIP). In the gut immune system, the CAIP is proposed to be activated directly by signals from the gut and indirectly by signals from the liver, which receives gut-derived bioactive substances via the portal vein and senses the status of the gut. The gut-brain axis and liver-brain-gut reflex arc regulate a wide variety of peripheral immune cells to maintain homeostasis in the gut. Therefore, targeting the neural reflex by methods such as VN stimulation is now under investigation for suppressing intestinal inflammation associated with IBDs. In this review, we describe the role of the VN in the regulation of intestinal immunity, and we discuss novel therapeutic approaches for IBDs that target neuroimmune interactions., (© The Japanese Society for Immunology. 2021. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

How liver tolerance is disrupted in immune-mediated liver injury is currently unclear. There is also insufficient information available regarding susceptibility, precipitation, escalation, and perpetuation of autoimmune hepatitis. To explore how dietary fiber influences hepatic damage, we applied the concanavalin A (ConA)-induced acute immune-mediated liver injury model in mice fed a diet supplemented with 6.8% inulin, a water-soluble fermentable fiber. Twelve hours after ConA administration, inulin-supplemented diet-fed mice demonstrated significantly alleviated hepatic damage histologically and serologically, with down-regulation of hepatic interferon-γ and tumor necrosis factor and reduced myeloperoxidase (MPO)-producing neutrophil infiltration. Preconditioning with an inulin-supplemented diet for 2 weeks significantly reduced hepatic adenosine triphosphate (ATP) content; suramin, a purinergic P2 receptor antagonist, abolished the protective effect. Of note, the portal plasma derived from mice fed the inulin-supplemented diet significantly alleviated ConA-induced immune-mediated liver injury. Mechanistically, increased portal short-chain fatty acid (SCFA) levels, such as those of acetate and butyrate, by inulin supplementation leads to up-regulation of hepatic γ-type peroxisome proliferator-activated receptor (Pparg) and uncoupling protein 2 (Ucp2), which uncouples mitochondrial ATP synthesis downstream of PPARγ. Pparg down-regulating small interfering RNA cancelled the protective effect of inulin supplementation against MPO-producing neutrophil infiltration and the subsequent immune-mediated liver injury, suggesting that the SCFA-PPARγ-UCP2 axis plays a key role in the protective effect by inulin supplementation. Moreover, significant changes in the gut microbiota, including increased operational taxonomic units in genera Akkermansia and Allobaculum, also characterized the protective effect of the inulin-supplemented diet. Conclusion: There is a possible unraveled etiopathophysiological link between the maintenance of liver tolerance and dietary fiber. The SCFA-PPARγ-UCP2 axis may provide therapeutic targets for immune-mediated liver injury in the future., (© 2021 The Authors. Hepatology Communications published by Wiley Periodicals LLC on behalf of the American Association for the Study of Liver Diseases.)

Non-alcoholic steatohepatitis (NASH) is a leading cause of chronic liver disease that can progress to liver fibrosis. Recent clinical advance suggests a reversibility of liver fibrosis, but the cellular and molecular mechanisms underlying NASH resolution remain unclarified. Here, using a murine diet-induced NASH and the subsequent resolution model, we demonstrate direct roles of CD8 + tissue-resident memory CD8 + T (CD8 + Trm) cells in resolving liver fibrosis. Single-cell transcriptome analysis and FACS analysis revealed CD69 + CD103 - CD8 + Trm cell enrichment in NASH resolution livers. The reduction of liver CD8 + Trm cells, maintained by tissue IL-15, significantly delayed fibrosis resolution, while adoptive transfer of these cells protected mice from fibrosis progression. During resolution, CD8 + Trm cells attracted hepatic stellate cells (HSCs) in a CCR5-dependent manner, and predisposed activated HSCs to FasL-Fas-mediated apoptosis. Histological assessment of patients with NASH revealed CD69 + CD8 + Trm abundance in fibrotic areas, further supporting their roles in humans. These results highlight the undefined role of liver CD8 + Trm in fibrosis resolution., (© 2021. The Author(s).)

Background and Aims: It remains unclear whether obesity increases the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C who achieved a sustained virological response (SVR) with antiviral therapy., Methods: In this multicenter cohort study, we enrolled patients with chronic hepatitis C who achieved SVR with interferon (IFN)-based therapy (IFN group) or direct-acting antiviral (DAA) therapy (DAA group) between January 1, 1990, and December 31, 2018. The patients underwent regular surveillance for HCC. Cumulative incidence of and the risk factors for HCC development after SVR were assessed using the Kaplan-Meier method and Cox proportional hazard regression analysis, respectively., Results: Among 2,055 patients (840 in the IFN group and 1,215 in the DAA group), 75 developed HCC (41 in the IFN group and 34 in the DAA group) during the mean observation period of 4.1 years. The incidence rates of HCC at 1, 2, and 3 years were 1.2, 1.9, and 3.0%, respectively. Multivariate analysis revealed that in addition to older age, lower albumin level, lower platelet count, higher alpha-fetoprotein level, and absence of dyslipidemia, obesity (body mass index ≥25 kg/m 2 ) and heavy alcohol consumption (≥60 g/day) were independent risk factors for HCC development, with adjusted hazard ratio (HR) of 2.53 (95% confidence interval [CI]: 1.51-4.25) and 2.56 (95% CI: 1.14-5.75), respectively. The adjusted HR was not significant between the 2 groups (DAA vs. IFN; HR 1.19, 95% CI: 0.61-2.33)., Conclusions: Obesity and heavy alcohol consumption increased the risk of HCC development after SVR., Competing Interests: Kazuhiko Koike has received research funding from Merck Sharp & Dohme, Chugai Pharmaceutical Co., Ltd, Bristol-Meyers Squibb, Gilead Sciences, AbbVie GK, Janssen Pharmaceutical K.K., and Mitsubishi Tanabe Pharma Corporation. Ryosuke Tateishi has received lecture fee from Merck Sharp & Dohme, Chugai Pharmaceutical Co., Ltd, Bristol-Meyers Squibb, Gilead Sciences, AbbVie GK, and Mitsubishi Tanabe Pharma Corporation. Tatsuya Minami has received lecture fee from Merck Sharp & Dohme, Gilead Sciences, and AbbVie GK. Hiroshi Yotsuyanagi has received lecture fee from Merck Sharp & Dohme, Bristol-Meyers Squibb, Gilead Sciences, and AbbVie GK. Naoya Kato has received research funding and lecture fee from Merck Sharp & Dohme, Chugai Pharmaceutical Co., Ltd, Bristol-Meyers Squibb, Gilead Sciences, AbbVie GK, Jansen Pharmaceutical K.K., and Mitsubishi Tanabe Pharma Corporation. Atsushi Tanaka has received lecture fee from Gilead Sciences and AbbVie GK. Yoshinari Asaoka has received lecture fee from Merck Sharp & Dohme, Gilead Sciences, and AbbVie GK. Kazuaki Inoue has received research funding from Chugai Pharmaceutical K.K, Bristol-Myers Squibb, AbbVie GK, and Merck Sharp & Dohme and has received lecture fee from AbbVie GK, Bristol-Myers Squibb, Merck Sharp & Dohme, and Gilead Sciences. Yasuo Tanaka has received research funding from Gilead Sciences. Hayato Nakagawa has received lecture fee from Merck Sharp & Dohme and Gilead Sciences. Takamasa Ohki has received lecture fee from Bayer Yakuhin Ltd and Eisai Co., Ltd., (Copyright © 2021 by S. Karger AG, Basel.)

Increased intestinal permeability and hepatic macrophage activation by endotoxins are involved in alcohol-induced liver injury pathogenesis. Long-term alcohol exposure conversely induces endotoxin immune tolerance; however, the precise mechanism and reversibility are unclear. Seventy-two alcohol-dependent patients with alcohol dehydrogenase-1B (ADH1B, rs1229984) and aldehyde dehydrogenase-2 (ALDH2, rs671) gene polymorphisms admitted for alcohol abstinence were enrolled. Blood and fecal samples were collected on admission and 4 weeks after alcohol cessation and were sequentially analyzed. Wild-type and ALDH2*2 transgenic mice were used to examine the effect of acetaldehyde exposure on liver immune responses. The productivity of inflammatory cytokines of peripheral CD14 + monocytes in response to LPS stimulation was significantly suppressed in alcohol dependent patients on admission relative to that in healthy controls, which was partially restored by alcohol abstinence with little impact on the gut microbiota composition. Notably, immune suppression was associated with ALDH2/ADH1B gene polymorphisms, and patients with a combination of ALDH2*1/*2 and ADH1B*2 genotypes, the most acetaldehyde-exposed group, demonstrated a deeply suppressed phenotype, suggesting a direct role of acetaldehyde. In vitro LPS and malondialdehyde-acetaldehyde adducted protein stimulation induced direct cytotoxicity on monocytes derived from healthy controls, and a second LPS stimulation suppressed the inflammatory cytokines production. Consistently, hepatic macrophages of ethanol-administered ALDH2*2 transgenic mice exhibited suppressed inflammatory cytokines production in response to LPS compared to that in wild-type mice, reinforcing the contribution of acetaldehyde to liver macrophage function. These results collectively provide new perspectives on the systemic influence of excessive alcohol consumption based on alcohol-metabolizing enzyme genetic polymorphisms.

The severe shortage of donor hearts hampered the cardiac transplantation to patients with advanced heart failure. Therefore, cardiac regenerative therapies are eagerly awaited as a substitution. Human induced pluripotent stem cells (hiPSCs) are realistic cell source for regenerative cardiomyocytes. The hiPSC-derived cardiomyocytes are highly expected to help the recovery of heart. Avoidance of teratoma formation and large-scale culture of cardiomyocytes are definitely necessary for clinical setting. The combination of pure cardiac spheroids and gelatin hydrogel succeeded to recover reduced ejection fraction. The feasible transplantation strategy including transplantation device for regenerative cardiomyocytes are established in this study., Competing Interests: This work was supported by the Highway Program for Realization of Regenerative Medicine (17bm054006h0007 [to Dr. Fukuda]) and the Research Project for Practical Applications of Regenerative Medicine (17bk010462h0001 [to Dr. Fukuda]) from the Japan Agency for Medical Research and Development, and a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology (nos. 15K09098 [to Dr. Kanazawa], 16K09507 [to Dr. Fujita], 19H03660 [to Dr. Fujita], 17H05067 [to Dr. Tohyama], 18K15903 [to Dr. Nakajima]). Drs. Kanazawa, Tohyama, Fukuda, and Fujita have patents related to this work. Drs. Tohyama, Shimizu, Kanazawa, Fukuda, and Fujita own equity in Heartseed, Inc. Dr. Tohyama is an advisor of Heartseed, Inc. Dr. Fukuda is a co-founder and CEO of Heartseed, Inc.; and receives a salary from Heartseed, Inc. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2021 The Authors.)

The MHC class I-like molecule CD1d is a nonpolymorphic antigen-presenting glycoprotein, and its ligands include glycolipids, such as α-GalCer. The complexes between CD1d and ligands activate natural killer T cells by T cell receptor recognition, leading to the secretion of various cytokines (IFN-γ, IL-4, IL-17A, etc.). Herein, we report structure-activity relationship studies of α-GalCer derivatives containing various functional groups in their lipid acyl chains. Several derivatives have been identified as potent CD1d ligands displaying higher cytokine induction levels and/or unique cytokine polarization. The studies also indicated that flexibility of the lipid moiety can affect the binding affinity, the total cytokine production level and/or cytokine biasing. Based on our immunological evaluation and investigation of physicochemical properties, we chose bisamide- and Bz amide-containing derivatives 2 and 3, and evaluated their in vivo efficacy in a DSS-induced model of ulcerative colitis. The derivative 3 that exhibits Th2- and Th17-biasing responses, demonstrated significant protective effects against intestinal inflammation in the DSS-induced model, after a single intraperitoneal injection.

Recent clinical and experimental evidence has evoked the concept of the gut-brain axis to explain mutual interactions between the central nervous system and gut microbiota that are closely associated with the bidirectional effects of inflammatory bowel disease and central nervous system disorders 1-4 . Despite recent advances in our understanding of neuroimmune interactions, it remains unclear how the gut and brain communicate to maintain gut immune homeostasis, including in the induction and maintenance of peripheral regulatory T cells (pT reg cells), and what environmental cues prompt the host to protect itself from development of inflammatory bowel diseases. Here we report a liver-brain-gut neural arc that ensures the proper differentiation and maintenance of pT reg cells in the gut. The hepatic vagal sensory afferent nerves are responsible for indirectly sensing the gut microenvironment and relaying the sensory inputs to the nucleus tractus solitarius of the brainstem, and ultimately to the vagal parasympathetic nerves and enteric neurons. Surgical and chemical perturbation of the vagal sensory afferents at the hepatic afferent level reduced the abundance of colonic pT reg cells; this was attributed to decreased aldehyde dehydrogenase (ALDH) expression and retinoic acid synthesis by intestinal antigen-presenting cells. Activation of muscarinic acetylcholine receptors directly induced ALDH gene expression in both human and mouse colonic antigen-presenting cells, whereas genetic ablation of these receptors abolished the stimulation of antigen-presenting cells in vitro. Disruption of left vagal sensory afferents from the liver to the brainstem in mouse models of colitis reduced the colonic pT reg cell pool, resulting in increased susceptibility to colitis. These results demonstrate that the novel vago-vagal liver-brain-gut reflex arc controls the number of pT reg cells and maintains gut homeostasis. Intervention in this autonomic feedback feedforward system could help in the development of therapeutic strategies to treat or prevent immunological disorders of the gut.