Single cell analysis revealed that two distinct, unique CD4+ T cell subsets were increased in the small intestinal intraepithelial lymphocytes of aged mice

Recent advances in research suggest that aging has a controllable chronic inflammatory disease aspect. Aging systemic T cells, which secrete pro-inflammatory factors, affect surrounding somatic cells, and accelerate the aging process through chronic inflammation, have attracted attention as potential therapeutic targets in aging. On the other hand, there are few reports on the aging of the intestinal immune system, which differs from the systemic immune system in many ways. In the current study, we investigated the age-related changes in the intestinal immune system, particularly in T cells. The most significant changes were observed in the CD4+ T cells in the small intestinal IEL, with a marked increase in this fraction in old mice and reduced expression of CD27 and CD28, which are characteristic of aging systemic T cells. The proliferative capacity of aging IEL CD4+ T cells was significantly more reduced than that of aging systemic T cells. Transcriptome analysis showed that the expression of inflammatory cytokines was not upregulated, whereas Cd8α, NK receptors, and Granzymes were upregulated in aging IEL CD4+ T cells. Functional analysis showed that aging IEL T cells had a higher cytotoxic function against intestinal tumor organoids in vitro than young IEL T cells. scRNAseq revealed that splenic T cells show a transition from naïve to memory T cells, whereas intestinal T cells show the emergence of a CD8αα+CD4+ T cell fraction in aged mice, which is rarely seen in young cells. Further analysis of the aging IEL CD4+ T cells showed that two unique subsets are increased that are distinct from the systemic CD4+ T cells. Subset 1 has a pro-inflammatory component, with expression of IFNγ and upregulation of NFkB signaling pathways. Subset 2 does not express IFNγ, but upregulates inhibitory molecules and nIEL markers. Expression of granzymes and Cd8a was common to both. These fractions were in opposite positions in the clustering by UMAP and had different TCR repertoires. They may be involved in the suppression of intestinal aging and longevity through anti-tumor immunity, elimination of senescent cells and stressed cells in the aging environment. This finding could be a breakthrough in aging research.

Protocol to generate large human intestinal organoids using a rotating bioreactor

Current techniques for producing induced-pluripotent-stem-cell-derived mid/hindgut spheroids have faced major hurdles in consistency and reproducibility. Here, we present a protocol that uses mid/hindgut cells to generate homogeneous spheroids that subsequently mature into human intestinal organoids (HIOs). We describe steps for stepwise differentiation and spheroid formation using a 96-well plate. We then detail cell maturation in a suspended state and the implementation of a rotational bioreactor platform to maximize the culture efficiency of larger HIOs. For complete details on the use and execution of this protocol, please refer to Takahashi et al.1.

Development and Application of Regenerative Medicine in Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by idiopathic and chronic inflammation arising elsewhere within the gastrointestinal tract. Consequently, the mucosal tissue is destroyed during the active phase of the disease, and therefore, spontaneous repair of damaged tissue is required to restore the function and long-term homeostasis of the intestinal mucosa. Also, in patients with refractory Crohn's disease, loss of massive intestinal function can lead to short bowel syndrome or may lead to fatal intestinal failure.

SUMMARY

The concept of mucosal healing shares the idea that both regulation of mucosal inflammation and repair of the damaged mucosa are critical to achieve the ideal clinical outcome in patients with IBD. However, current treatments lack the option of those targeted to mucosal repair, and therefore, patients must achieve mucosal healing depending on their intrinsic system. To counteract inflammation-induced mucosal damage, various biologics or cell-based treatments are currently being developed. In the early developmental phase, various growth factors have been tested for their ability to promote mucosal repair. However, most of these factors did not show clinical benefit, except the recombinant glucagon-like peptide-2 (GLP-2). On the contrary, cell-based treatments are rapidly emerging, using both somatic stem cells and pluripotent stem cells.

KEY MESSAGES

In this review, we focus on the current state of factor-based or cell-based regenerative medicine in the treatment of IBD. Additionally, we would like to introduce current examples of tissue engineering technologies and provide future prospects for the application of regenerative medicine in IBD.

Collagen type I-mediated mechanotransduction controls epithelial cell fate conversion during intestinal inflammation

BACKGROUND

The emerging concepts of fetal-like reprogramming following tissue injury have been well recognized as an important cue for resolving regenerative mechanisms of intestinal epithelium during inflammation. We previously revealed that the remodeling of mesenchyme with collagen fibril induces YAP/TAZ-dependent fate conversion of intestinal/colonic epithelial cells covering the wound bed towards fetal-like progenitors. To fully elucidate the mechanisms underlying the link between extracellular matrix (ECM) remodeling of mesenchyme and fetal-like reprogramming of epithelial cells, it is critical to understand how collagen type I influence the phenotype of epithelial cells. In this study, we utilize collagen sphere, which is the epithelial organoids cultured in purified collagen type I, to understand the mechanisms of the inflammatory associated reprogramming. Resolving the entire landscape of regulatory networks of the collagen sphere is useful to dissect the reprogrammed signature of the intestinal epithelium.

METHODS

We performed microarray, RNA-seq, and ATAC-seq analyses of the murine collagen sphere in comparison with Matrigel organoid and fetal enterosphere (FEnS). We subsequently cultured human colon epithelium in collagen type I and performed RNA-seq analysis. The enriched genes were validated by gene expression comparison between published gene sets and immunofluorescence in pathological specimens of ulcerative colitis (UC).

RESULTS

The murine collagen sphere was confirmed to have inflammatory and regenerative signatures from RNA-seq analysis. ATAC-seq analysis confirmed that the YAP/TAZ-TEAD axis plays a central role in the induction of the distinctive signature. Among them, TAZ has implied its relevant role in the process of reprogramming and the ATAC-based motif analysis demonstrated not only Tead proteins, but also Fra1 and Runx2, which are highly enriched in the collagen sphere. Additionally, the human collagen sphere also showed a highly significant enrichment of both inflammatory and fetal-like signatures. Immunofluorescence staining confirmed that the representative genes in the human collagen sphere were highly expressed in the inflammatory region of ulcerative colitis.

CONCLUSIONS

Collagen type I showed a significant influence in the acquisition of the reprogrammed inflammatory signature in both mice and humans. Dissection of the cell fate conversion and its mechanisms shown in this study can enhance our understanding of how the epithelial signature of inflammation is influenced by the ECM niche.

Suspension culture in a rotating bioreactor for efficient generation of human intestinal organoids

Human intestinal organoids (HIOs) derived from human pluripotent stem cells (hPSCs) hold great promise for translational medical applications. A common method to obtain HIOs has been to harvest floating hindgut spheroids arising from hPSCs. As this technique is elegant but burdensome due to the complex protocol and line-to-line variability, a more feasible method is desired. Here, we establish a robust differentiation method into suspension-cultured HIOs (s-HIOs) by seeding dissociated cells on a spheroid-forming plate. This protocol realizes the reliable generation of size-controllable spheroids. Under optimized conditions in a rotating bioreactor, the generated spheroids quickly grow and mature into large s-HIOs with supporting mesenchyme. Upon mesenteric transplantation, s-HIOs further mature and develop complex tissue architecture in vivo. This method demonstrates that intestinal tissue can be generated from iPSC-derived HIOs via suspension induction and bioreactor maturation, establishing a reliable culture platform with wide applications in regenerative medicine.

Serum autotaxin level predicts future cardiac events in patients with dilated cardiomyopathy

Background

Autotaxin (ATX) has been reported to promote myocardial inflammation and subsequent cardiac remodeling through lysophosphatidic acid (LPA) production. However, the prognostic impact of ATX has not been clarified in dilated cardiomyopathy (DCM).

Purpose

We aimed to investigate the prognostic impact of ATX in patients with DCM.

Methods

We enrolled 104 DCM patients (49.8 years, 76 males). The subjects underwent blood sampling, echocardiography, cardiac catheterization, and endomyocardial biopsy. Gender differences in serum ATX levels have been reported, thus we divided the subjects into two groups using median serum ATX levels for men and women: High-ATX group and Low-ATX group. All patients were followed up by expert cardiologists. The cardiac event was defined as a composite of cardiac death and hospitalization for worsening heart failure.

Results

Eighty-nine percent of the subjects were classified as New York Heart Association functional class I or II. Female patients had higher serum ATX levels than male patients, with median values of 257.0 ng/mL and 203.5 ng/mL, respectively (Figure A). The average left ventricular ejection fraction and brain natriuretic peptide levels were 30.6% and 122.5 pg/mL. In survival analysis, cumulative event-free probability was significantly lower in High ATX group (p=0.007, Figure B). In Cox proportional hazards analysis, High-ATX was one of the independent predictors of composite cardiac events (Hazards Ratio, 2.575; p=0.043). On the other hand, high sensitive C-reactive protein and collagen volume fraction in myocardial samples were not significant predictors.

Conclusion

High serum ATX level was associated with poor prognosis in patients with DCM.

Funding Acknowledgement

Type of funding sources: None. Gender difference in autotaxin levelsSurvival analysis of cardiac events

Clinical significance of spleen size in patients with heart failure

Background

The spleen is an important organ that stores blood, releases erythrocytes or monocytes, and destroys no-longer-needed platelets. It can reserve 20–30% of the total blood volume, and its size is reduced in hypovolemic shock. However, the clinical significance of the spleen size in patients with heart failure (HF) remains unclear.

Purpose

The purpose of this study was to investigate the relationship between spleen size, hemodynamic parameters, and prognosis in patients with HF.

Methods

A total of 219 patients with clinically stable HF were enrolled. All patients underwent right heart catheterisation and computed tomography. The spleen size was measured using computed tomography volumetry. In addition, spleen volume was assessed using the spleen volume index (SVI), corrected for body surface area. Cardiac events were composite endpoints of cardiac death, hospitalisation for worsening HF, fatal arrhythmias, implantation of cardiac devices, implantation of left ventricular assist devices, and unexpected percutaneous coronary intervention or cardiac surgery. Spearman's rank correlation coefficient was used to examine the relationship between spleen volume and hemodynamic parameters. Multivariate Cox hazard regression models were used to investigate whether SVI was an independent determinant of cardiac events.

Results

Of the 219 patients (median age, 54 [interquartile range] 46–64 years), 145 (66%) were males. The median (interquartile range) spleen volume and SVI was 118.0 (91.5–156.0) mL and 67.8 (54.9–87.2) mL/m2, respectively. SVI was positively correlated with cardiac output (r=0.269, P<0.001), and negatively correlated with systemic vascular resistance (r=−0.302, P<0.001) (Figure 1). A total of 70 cardiac events were observed, and the optimal cut-off value of SVI for cardiac events was 68.9 mL/m2 in the receiver operating characteristic analysis. Patients were divided into two groups: low-SVI (n=107, <68.9 mL/m2) and high-SVI groups (n=112, ≥68.9 mL/m2). Blood adrenaline concentration was higher in the low-SVI group than in the high-SVI group (0.039 [0.020–0.057] ng/mL vs 0.026 [0.014–0.044] ng/mL, P=0.004). The low-SVI group had more cardiac events than the high-SVI group (log-rank test, P<0.001) (Figure 2). In the multivariate Cox proportional hazard model, the low-SVI group was an independent predictor of cardiac events, even when adjusted for the conventional validated HF risk score, blood catecholamine levels, and hemodynamic parameters.

Conclusion

The spleen size may affect the prognosis in patients with HF, reflecting haemodynamics, including systemic circulating blood volume status and sympathetic nerve activity.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Clinical impact of pulmonary artery to aorta diameter ratio on left ventricular reverse remodeling in patients with dilated cardiomyopathy

Background

Left ventricular reverse remodeling (LVRR) is an important predictor for a good prognosis in patients with dilated cardiomyopathy (DCM). Previous reports indicated the pulmonary artery diameter (PAD) to ascending aortic diameter (AoD) ratio as a predictor of adverse outcomes in heart failure patients. However, the impact of the PAD/AoD ratio for predicting LVRR in patients with DCM is unknown.

Aim

The aim of this study is to investigate the association between PAD/AoD ratio and LVRR in patients with DCM.

Methods

From a prospective study, clinically stable DCM patients who were investigated the LVRR on echocardiography and underwent CT at baseline were enrolled. LVRR is defined as left ventricular (LV) ejection fraction increase of 10% and a decrease in indexed LV end-diastolic diameter of 10% compared to those at baseline. PAD and AoD data was collected with nonenhanced computed tomography images at baseline.

Results

In sixty-nine patients (mean age 50.0±13.3 years), the mean LV ejection fraction was 29.8%, and mean LV end-diastolic dimension was 64.5mm, and both of which data was no significant difference between patients with or without LVRR. LVRR was observed in 23 (33.3%) patients. The PAD/AoD ratio was significantly lower in patients with LVRR than without LVRR (81.4% vs. 92.4%, p=0.003). By ROC analysis, the best cut-off for the detection of LVRR was found for a PAD/AoD ratio of 0.9. From multivariate analyses, PAD/AoD ratio was identified as a significant predictor of LVRR. After a median follow-up duration of 2.5 years, the DCM patients with PAD/AoD≥0.9 revealed a significant higher cardiac event than those with PAD/AoD<0.9 (log-rank, p=0.007)

Conclusions

The PAD/AoD ratio is useful for predicting LVRR in patients with DCM. The DCM patients with high PAD/AoD ratio had a poor long-term outcome.

Funding Acknowledgement

Type of funding sources: None. ROC curve for LVRR predictionKaplan-Meier survival curves

KSR1- and ERK-dependent translational regulation of the epithelial-to-mesenchymal transition

The epithelial-to-mesenchymal transition (EMT) is considered a transcriptional process that induces a switch in cells from a polarized state to a migratory phenotype. Here, we show that KSR1 and ERK promote EMT-like phenotype through the preferential translation of Epithelial-Stromal Interaction 1 (EPSTI1), which is required to induce the switch from E- to N-cadherin and coordinate migratory and invasive behavior. EPSTI1 is overexpressed in human colorectal cancer (CRC) cells. Disruption of KSR1 or EPSTI1 significantly impairs cell migration and invasion in vitro, and reverses EMT-like phenotype, in part, by decreasing the expression of N-cadherin and the transcriptional repressors of E-cadherin expression, ZEB1 and Slug. In CRC cells lacking KSR1, ectopic EPSTI1 expression restored the E- to N-cadherin switch, migration, invasion, and anchorage-independent growth. KSR1-dependent induction of EMT-like phenotype via selective translation of mRNAs reveals its underappreciated role in remodeling the translational landscape of CRC cells to promote their migratory and invasive behavior.

Notch and TNF-α signaling promote cytoplasmic accumulation of OLFM4 in intestinal epithelium cells and exhibit a cell protective role in the inflamed mucosa of IBD patients

Notch signaling is activated in the intestinal epithelial cells (IECs) of patients with inflammatory bowel disease (IBD), and contributes to mucosal regeneration. Our previous study indicated that TNF-α and Notch signaling may synergistically promote the expression of the intestinal stem cell (ISC) marker OLFM4 in human IECs. In the present study, we investigated the gene regulation and function of OLFM4 in human IEC lines. We confirmed that TNF-α and Notch synergistically upregulate the mRNA expression of OLFM4. Luciferase reporter assay showed that OLFM4 transcription is regulated by the synergy of TNF-α and Notch. At the protein level, synergy between TNF-α and Notch promoted cytoplasmic accumulation of OLFM4, which has potential anti-apoptotic properties in human IECs. Analysis of patient-derived tissues and organoids consistently showed cytoplasmic accumulation of OLFM4 in response to NF-κB and Notch activation. Cytoplasmic accumulation of OLFM4 in human IECs is tightly regulated by Notch and TNF-α in synergy. Such cytoplasmic accumulation of OLFM4 may have a cell-protective role in the inflamed mucosa of patients with IBD.

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Notch and TNF-α signaling is important in IECs of patients with IBD.

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Notch and TNF-α signaling promotes the cytoplasmic accumulation of OLFM4.

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OLFM4 accumulation may have anti-apoptotic properties.

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OLFM4 could protect against mucosal inflammation in IBD.

Functional analysis of isoflavones using patient-derived human colonic organoids

Inflammatory bowel disease (IBD) comprises two major subtypes, ulcerative colitis (UC) and Crohn's disease, which are multifactorial diseases that may develop due to genetic susceptibility, dysbiosis, or environmental factors. Environmental triggers of IBD include food-borne factors, and a previous nationwide survey in Japan identified pre-illness consumption of isoflavones as a risk factor for UC. However, the precise mechanisms involved in the detrimental effects of isoflavones on the intestinal mucosa remain unclear. The present study employed human colonic organoids (hCOs) to investigate the functional effect of two representative isoflavones, genistein and daidzein, on human colonic epithelial cells. The addition of genistein to organoid reformation assays significantly decreased the number and size of reformed hCOs compared with control and daidzein treatment, indicating an inhibitory effect of genistein on colonic cell/progenitor cell function. Evaluation of the phosphorylation status of 49 different receptor tyrosine kinases showed that genistein selectively inhibited phosphorylation of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (HGFR). We established a two-dimensional wound-repair model using hCOs and showed that genistein significantly delayed the overall wound-repair response. Our results collectively show that genistein may exert its detrimental effects on the intestinal mucosa via negative regulation of stem/progenitor cell function, possibly leading to sustained mucosal injury and the development of UC.

New methods for determination of the keyhole position in the lateral suboccipital approach to avoid transverse-sigmoid sinus injury: Proposition of the groove line as a new surgical landmark

PURPOSE

The asterion is frequently used as an anatomical landmark to determine the location of a keyhole in the lateral suboccipital approach used in craniotomies. However, the asterion may not be ideal because of large individual differences among patients. We examined a simple and safe method for determining an optimal keyhole position (KP) using the digastric groove as a new landmark in the lateral suboccipital approach.

METHODS

Thirty-three patients with trigeminal neuralgia who underwent surgery in our institute between April 2014 and December 2018 were included. The groove line (GL) was designed accurately, extending the digastric groove on the surface of the occipital bone, as the x-axis. The y-axis was depicted from the posterior edge of the digastric groove (the groove point: GP) vertical to the GL. The x-y coordinates represented the distances from GP on each axis. The x-y coordinates of median edge of the transverse-sigmoid sinus (TSJ point), asterion, and the intersection of the GL and transverse sinus (the transverse point: TP) were investigated, based on intraoperative findings and recorded videos.

RESULTS

The x-y coordinated of the TSJ point were (23.9±3.9, 7.2±3.6). In all patients, the TSJ point was located superior to the GL. The x-y coordinates of the asterion were (27.3±6.0, 8.9±4.1), and in 28 of the 33 patients, their coordinates exceeded the TSJ points. The x-coordinate of the TP was 29.5±4.5, and was located behind the TSJ point on the GL in all patients. The shortest distance between the TSJ points and TP was approximately 3mm. According to these measurements, we decided that the optimal KP would be at 20mm from the GP, subjacent to the GL.

CONCLUSIONS

Our methods of using the GL as a new surgical landmark for setting the optimal KP is simple, safe, and useful.

A phase III study of adjuvant chemotherapy in patients with completely resected, node-negative non–small cell lung cancer (JCOG 0707)

Objective

To evaluate efficacy of S-1 (tegafur/gimeracil/oteracil), an active novel fluoropyrimidine, as compared to UFT (tegafur/uracil) as a postoperative adjuvant therapy in patients with node-negative non–small cell lung cancer (NSCLC).

Methods

Eligible patients had undergone complete resection of p-stage I (T1 with tumor diameter >2 cm or T2-N0M0 by 5th edition Union for International Cancer Control TNM) NSCLC, and were randomized to receive oral UFT 250 mg/m²/day for 2 years (Arm A) or oral S-1 80 mg/m²/day for 2 weeks with a 1-week rest period, for 1 year (Arm B). The primary end point was relapse-free survival (RFS), with 80% power and a one-sided type I error of 0.05.

Results

From November 2008 to December 2013, 963 patients were enrolled (Arm A: 482, Arm B: 481). Toxicities (hematologic/nonhematologic) of grade 3 or more were observed in 15.9 (1.5/14.7)% in Arm A, and in 14.9 (3.6/12.1)% in Arm B, respectively. At data cut-off in December 2018, the hazard ratio for RFS was 1.06 (95% confidence interval, 0.82-1.36), showing no superiority of S-1 over UFT. The hazard ratio of overall survival (OS) was 1.10 (95% confidence interval, 0.81-1.50). The 5-year RFS/OS were 79.4%/88.8% in Arm A and 79.5%/89.7% in Arm B, respectively. The original NSCLC accounted for 58%/53%, respectively, of the Arm A/Arm B OS events. Secondary malignancies were observed in 85 (17.8%) and 84 (17.8%) individuals in Arm A and Arm B, respectively.

Conclusions

S-1 was not superior to UFT as postoperative adjuvant therapy in node-negative NSCLC. Future investigation should incorporate identification of high-risk populations for recurrence.

5-FU promotes stemness of colorectal cancer via p53-mediated WNT/β-catenin pathway activation

5-Fluorouracil (5-FU) remains the first-line treatment for colorectal cancer (CRC). Although 5-FU initially de-bulks the tumor mass, recurrence after chemotherapy is the barrier to effective clinical outcomes for CRC patients. Here, we demonstrate that p53 promotes WNT3 transcription, leading to activation of the WNT/β-catenin pathway in Apc^Min/+/Lgr5^EGFP mice, CRC patient-derived tumor organoids (PDTOs) and patient-derived tumor cells (PDCs). Through this regulation, 5-FU induces activation and enrichment of cancer stem cells (CSCs) in the residual tumors, contributing to recurrence after treatment. Combinatorial treatment of a WNT inhibitor and 5-FU effectively suppresses the CSCs and reduces tumor regrowth after discontinuation of treatment. These findings indicate p53 as a critical mediator of 5-FU-induced CSC activation via the WNT/β-catenin signaling pathway and highlight the significance of combinatorial treatment of WNT inhibitor and 5-FU as a compelling therapeutic strategy to improve the poor outcomes of current 5-FU-based therapies for CRC patients.

Abstract 307: KSR1-dependent modulation of the translational landscape in Ras-driven colorectal cancer

KRAS is mutated and activated in an estimated 40% of colon cancers but has proven difficult to target directly due to the lack of drug-binding pockets on the surface of Ras. Thus, identifying effectors that transmit signals from oncogenic Ras is a critical step in targeting vulnerabilities in the tumors of patients with colorectal cancer (CRC). Kinase Suppressor of Ras 1 (KSR1) is a molecular scaffold that coordinates the interaction of effectors in the Raf/MEK/ERK signaling cascade downstream of Ras. KSR1 is necessary for oncogenic transformation of cells expressing mutated Ras but is dispensable for normal cell growth making KSR1 an attractive therapeutic target for Ras-driven colon cancers. In CRC cells, KSR1 and ERK mediate Ras-dependent effects on protein translation, notably driving cap-dependent and cap-independent translation of the Myc oncogene. Depletion of KSR1 or treatment with ERK inhibitor (SCH772984) leads to a decrease in phophorylated 4EBP1 and a decrease in PDCD4, which collectively impair protein translation, notably leading to a decrease in Myc translation. Patient-derived CRC organoids with deletion of APC, p53, and SMAD4, and an activating G12D mutation in KRAS treated with ERK inhibitor show a marked decrease in Myc protein expression, coincident with changes in PDCD4 and 4EBP1 that impair protein translation. These observations indicate that the KSR1-dependent ERK activation observed in CRC cell lines is present in pre-clinical colon tumoroid models. Genome-wide polysome profiling in CRC cell lines HCT116 and HCT15 depleted of KSR1 identified mRNAs that were preferentially translated in a KSR1 and ERK-dependent manner. Several of these mRNAs were previously predicted by our Functional Signature Ontology (FUSION) screen to be critical to CRC viability but dispensable for normal cell growth. GSEA identified functional classes of mRNAs whose translation is KSR1-dependent, including mediators of oncogenic signaling in pathways that regulate mTOR, MAPK, WNT and JAK-STAT. Our data suggest that an essential component of oncogenic Ras-induced and KSR1-dependent signaling is the preferential translation of mRNAs supporting the transformed phenotype of CRC cells.

Citation Format: Heidi Vieira, Chaitra Rao, Adrian R. Black, Siddesh Southekal, Tomohiro Mizutani, Babu Guda, Hans Clevers, Jennifer D. Black, Robert E. Lewis. KSR1-dependent modulation of the translational landscape in Ras-driven colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 307.

Mutational signature in colorectal cancer caused by genotoxic pks+ E. coli

Various species of the intestinal microbiota have been associated with the development of colorectal cancer1,2, but it has not been demonstrated that bacteria have a direct role in the occurrence of oncogenic mutations. Escherichia coli can carry the pathogenicity island pks, which encodes a set of enzymes that synthesize colibactin3. This compound is believed to alkylate DNA on adenine residues4,5 and induces double-strand breaks in cultured cells3. Here we expose human intestinal organoids to genotoxic pks+ E. coli by repeated luminal injection over five months. Whole-genome sequencing of clonal organoids before and after this exposure revealed a distinct mutational signature that was absent from organoids injected with isogenic pks-mutant bacteria. The same mutational signature was detected in a subset of 5,876 human cancer genomes from two independent cohorts, predominantly in colorectal cancer. Our study describes a distinct mutational signature in colorectal cancer and implies that the underlying mutational process results directly from past exposure to bacteria carrying the colibactin-producing pks pathogenicity island.

Gradient subthalamic neurodegeneration and tau pathology in the hypoglossal nucleus as essential pathological markers of progressive supranuclear palsy - Richardson syndrome

Progressive supranuclear palsy - Richardson syndrome (PSP-RS) was first described in 1964 by Steele et al. Tau pathology has not been reported in the hypoglossal nuclei of PSP-RS patients, whereas Steele et al. described gliosis with no remarkable neuronal losses in the hypoglossal nucleus. This study aimed to investigate the distribution and degree of tau pathology-associated neurodegeneration, with an emphasis on the hypoglossal nucleus, in patients with PSP-RS. Six clinicopathologically proven PSP-RS cases were included in this study. All patients were clinicopathologically and immunohistochemically re-evaluated. This study confirmed the following neuropathological characteristics of PSP-RS: (1) neurodegeneration usually affects the striatonigral system and cerebellar dentate nucleus; (2) the cerebellar afferent system in PSP-RS is affected by absent-to-mild neurodegeneration; and (3) the extent of tau distribution throughout the central nervous system is greater than the extent of neurodegeneration. Furthermore, we found that subthalamic neurodegeneration was more prominent in the ventromedial region than in the dorsolateral region. Nevertheless, the tau pathology showed no remarkable differences between these two sites. Interestingly, the tau pathology was frequently observed in the hypoglossal nuclei of PSP-RS patients. Gradient neurodegeneration of the subthalamus and tau pathology in the hypoglossal nucleus could be regarded as essential pathological features of PSP-RS.

A multicenter study on the clinical characteristics and risk factors of in-hospital mortality in patients with mechanical complications following acute myocardial infarction

Mechanical complications (MCs) following acute myocardial infarction (AMI), such as ventricular septal rupture (VSR), free-wall rupture (FWR), and papillary muscle rupture (PMR), are fatal. However, the risk factors of in-hospital mortality among patients with MCs have not been previously reported in Japan. The purpose of this study was to evaluate the prognostic factors of in-hospital mortality in these patients. The study cohort consisted of 233 consecutive patients with MCs from the registry of 10 facilities in the Cardiovascular Research Consortium-8 Universities (CIRC-8U) in East Japan between 1997 and 2014 (2.3% of 10,278 AMI patients). The authors conducted a retrospective observational study to analyse the correlation between the subtypes of MCs with in-hospital mortality, clinical data, and medical treatment. We observed a decreasing incidence of MC (1997-2004: 3.7%, 2005-2010: 2.1%, 2011-2014: 1.9%, p < 0.001). In-hospital mortality among patients with MCs was 46%. Thirty-three percent of patients with MCs were not able to undergo surgical repair due to advanced age or severe cardiogenic shock. In-hospital mortality among patients who had undergone surgical repair was 29% (VSR: 21%, FWR: 33%, PMR: 60%). In patients with MCs, hazard ratio for in-hospital mortality according to multivariate analysis of without surgical repair was 5.63 (95% CI 3.54-8.95). In patients with surgical repair, the hazard ratios of blow-out-type FWR (5.53, 95% confidence interval (CI) 2.22-13.76), those with renal dysfunction (3.11, 95% CI 1.37-7.05), and those receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) (3.79, 95% CI 1.81-7.96) were significantly high. Although primary percutaneous coronary intervention (PCI) is associated with decreased incidence of MCs, high in-hospital mortality persisted in patients with MCs that also presented with renal dysfunction and in those requiring VA-ECMO. Early detection and surgical repair of MCs are essential.

Primary Intestinal Epithelial Organoid Culture

The intestinal epithelium is known as one of the most regenerative tissues in our body. The lining of the intestine is composed of a single layer of epithelial cells generated by rapidly renewing stem cells residing at the crypt bottoms, resulting in a flow of cells to the villus tips. The stereotypical crypt-villus architecture makes the intestine an ideal model for stem cell research. Based on recent advances in research of stem cell niche signals in vivo, we have established an intestinal epithelial stem cell culture method. Under this culture condition, single Lgr5+ intestinal stem cells (ISCs) or isolated whole crypts efficiently expand into three-dimensional spherical structures recapitulating the intestinal crypt-villus organization. These organoids can be passaged weekly and maintained for years in culture. Moreover, they can be cryopreserved. As intestinal organoids recapitulate many aspects of the epithelial biology and are amenable to most, if not all, current experimental manipulations, they are widely used to study stem cell biology, cell fate determination, gene function, and disease mechanism.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in an African pygmy hedgehog (Atelerix albiventris) colony in Japan

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A novel adenovirus outbreak occurred in a colony of African pygmy hedgehogs (APHs).

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An African pygmy hedgehog adenovirus 1 (AhAdV-1) infection was confirmed in 13 APHs.

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AhAdV-1 was isolated from one APH.

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Five APHs died during the outbreak and AhAdV-1 can cause fatal pneumonia in a case.

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AhAdV-1 should be monitored as a potential cause of emerging infections in APHs.

An African pygmy hedgehog adenovirus 1 (AhAdV-1) outbreak in a colony of 24 African pygmy hedgehogs (APHs) with a case of fatal pneumonia occurred in Japan. Thirteen out of a colony of 15 APHs with respiratory symptoms were diagnosed with AhAdV-1 infection based on the detection of AhAdV-1 genome in throat/nasal swabs and further one APH was diagnosed on isolation of the virus. Five infected APHs died during the outbreak and AhAdV-1 caused severe pneumonia and death in one case. After the outbreak, persistent AhAdV-1 infection was suggested in one surviving APH. AhAdV-1 is a novel adenovirus and is suspected to be an emerging pathogen.

Abstract OT2-01-05: A randomized controlled trial comparing post-operative intensive follow-up with standard follow-up in high-risk breast cancer patients (JCOG1204: INSPIRE)

Background: The standard follow-up after surgery for breast cancer includes periodic interviews, clinical examinations, and mammography, but many institutions are conducting intensive follow-up including periodic computed tomography(CT), magnetic resonance imaging(MRI), and bone scintigraphy in the world, despite the lack of evidence to support this approach. While intensive follow-up may contribute to prolonged survival through earlier diagnosis and treatment of relapse, it has the disadvantages of high effort and costs placed on patients(pts) and healthcare workers, radiation exposure for imaging examinations, and overtreatment owing to false-positive results. Although past two randomized trials could not show significant difference in overall survival (OS), as imaging methods have remarkably improved, leading to the earlier detection of relapse, and medical therapies have remarkably improved in recent years, randomized controlled trials are needed to confirm whether intensive follow-up can really prolong survival sufficiently to offset these disadvantages in high-risk breast cancer pts.

Trial design: This study is a multi-institutional two-arm open label randomized controlled phase III trial being conducted with the participation of 42 hospitals belonging to the Breast Cancer Study Group of Japan Clinical Oncology Group. Eligible pts are randomized either to the intensive follow-up group or to the standard follow-up group; the former will undergo physical examination, bone scintigraphy, chest and abdominal CT, brain MRI/CT and frequent tumor markers, whereas the latter will undergo physical examination at the same frequency and tumor markers will be evaluated once a year. Mammography once a year is planned for both groups. This trial has been registered at the UMIN Clinical Trials Registry as UMIN000012429.

Eligibility criteria: High-risk breast cancer pts, who are expected to have recurrence rates of over 30% within 5 years after surgery. The main inclusion criteria are as follows: four or more axillary nodal metastases in the estrogen receptor (ER) positive pts without neoadjuvant chemotherapy(NC)., axillary node metastases in ER-negative pts without NC, axillary nodal metastases in ER-positive pts with NC, histologically proven residual invasive cancer in the breast or axilla in ER-negative with NC.

Specific Aims: The primary endpoint is OS, and secondary endpoints are disease-free survival, relapse-free survival, distant metastasis–free survival, OS in intrinsic subtypes, actual number of implemented examinations, compliance with pre-specified examinations, and adverse events.

Statistical methods: The primary endpoint will require a total of 538 events to be assessed in order to obtain a statistical power of 80% with a one-sided significance level of 0.05. Thus, the planned sample size to compare the two survival curves is set at 1500 pts, assuming an accrual time of 6 years and a follow-up time of 7 years according to the Schoenfeld and Richter's method.

Present accrual and target accrual: The trial was activated in November 2013. 773 pts have been enrolled by the end of June 2018.

Contact: Principal investigator Takashi Hojo MD tahojo@east.ncc.go.jp

Citation Format: Hojo T, Masuda N, Shibata T, Mizutani T, Shien T, Kinoshita T, Iwatani T, Kanbayashi C, Kitagawa D, Tsuneizumi M, Iwata H. A randomized controlled trial comparing post-operative intensive follow-up with standard follow-up in high-risk breast cancer patients (JCOG1204: INSPIRE) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-01-05.

New precise measurements of muonium hyperfine structure at J-PARC MUSE

High precision measurements of the ground state hyperfine structure (HFS) of muonium is a stringent tool for testing bound-state quantum electrodynamics (QED) theory, determining fundamental constants of the muon magnetic moment and mass, and searches for new physics. Muonium is the most suitable system to test QED because both theoretical and experimental values can be precisely determined. Previous measurements were performed decades ago at LAMPF with uncertainties mostly dominated by statistical errors. At the J-PARC Muon Science Facility (MUSE), the MuSEUM collaboration is planning complementary measurements of muonium HFS both at zero and high magnetic field. The new high-intensity muon beam that will soon be available at H-Line will provide an opportunity to improve the precision of these measurements by one order of magnitude. An overview of the different aspects of these new muonium HFS measurements, the current status of the preparation for high-field measurements, and the latest results at zero field are presented.

Contribution of ATOH1+ Cells to the Homeostasis, Repair, and Tumorigenesis of the Colonic Epithelium

ATOH1 is a master transcription factor for the secretory lineage differentiation of intestinal epithelial cells (IECs). However, the comprehensive contribution of ATOH1⁺ secretory lineage IECs to the homeostasis, repair, and tumorigenesis of the intestinal epithelium remains uncertain. Through our ATOH1⁺ cell-lineage tracing, we show here that a definite number of ATOH1⁺ IECs retain stem cell properties and can form ATOH1⁺IEC-derived clonal ribbons (ATOH1⁺ICRs) under completely homeostatic conditions. Interestingly, colonic ATOH1⁺ IECs appeared to exhibit their stem cell function more frequently compared with those of the small intestine. Consistently, the formation of ATOH1⁺ICRs was significantly enhanced upon dextran sodium sulfate colitis-induced mucosal damage. In addition, colonic ATOH1⁺ IECs acquired tumor stem cell-like properties in the azoxymethane-DSS tumor model. Our results reveal an unexpected contribution of colonic ATOH1⁺ IECs to maintaining the stem cell population under both homeostatic and pathologic conditions and further illustrate the high plasticity of the crypt-intrinsic stem cell hierarchy.

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Intestinal ATOH1⁺ cells can exhibit stem cell properties under homeostatic conditions

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Recruitment of ATOH1⁺ cell-derived stem cells is enhanced by inflammation

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Cell-intrinsic NF-kB signaling promotes generation of ATOH1⁺ cell-derived stem cells

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ATOH1⁺ tumor stem cells contribute to the development of colitis-associated tumors

Molecular epidemiological survey and phylogenetic analysis of bovine influenza D virus in Japan

The influenza D virus, a new member of the Orthomyxoviridae family, is predominantly found in cattle. Although viral pathology and clinical disease in cattle appear mild, this virus plays an important role as a trigger of bovine respiratory disease (BRD). BRD is a costly illness worldwide. Thus, epidemiological surveys of the influenza D virus are necessary. Here, we conducted a molecular epidemiological survey for the influenza D virus in healthy and respiratory-diseased cattle in Japan. We found that 2.1% (8/377) of the cattle were infected with influenza D. The cattle with and without respiratory symptoms had approximately equal amounts of the virus. A full-genome sequence analysis revealed that the influenza D virus that was isolated in Japan formed an individual cluster that was distinct from the strains found in other countries. These results suggest that this virus might have evolved uniquely in Japan over a long period of time and that the viral pathology of Japanese strains might be different from the strains found in other countries. Continuous surveillance is required to determine the importance of this virus and to characterize its evolution.

Use of CRISPR-modified human stem cell organoids to study the origin of mutational signatures in cancer

Mutational processes underlie cancer initiation and progression. Signatures of these processes in cancer genomes may explain cancer etiology and could hold diagnostic and prognostic value. We developed a strategy that can be used to explore the origin of cancer-associated mutational signatures. We used CRISPR-Cas9 technology to delete key DNA repair genes in human colon organoids, followed by delayed subcloning and whole-genome sequencing. We found that mutation accumulation in organoids deficient in the mismatch repair gene MLH1 is driven by replication errors and accurately models the mutation profiles observed in mismatch repair-deficient colorectal cancers. Application of this strategy to the cancer predisposition gene NTHL1, which encodes a base excision repair protein, revealed a mutational footprint (signature 30) previously observed in a breast cancer cohort. We show that signature 30 can arise from germline NTHL1 mutations.

Oncogene-inducible organoids as a miniature platform to assess cancer characteristics

Direct effects of oncogenic proteins or inhibitor treatments on signaling pathways are difficult to assess in transgenic mice. In this issue, Riemer et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201610058) demonstrate that oncogene-inducible organoids offer the experimental versatility of two-dimensional cell lines, while closely representing the in vivo situation.

Data showing proliferation and differentiation of intestinal epithelial cells under targeted depletion of Notch ligands in mouse intestine

The data on the immunohistochemical analysis of conditional Notch ligand knockout mice is presented. Targeted deletion of Jag1, Dll1, Dll4, or Dll1 plus Dll4 in Lgr5^+ve cells was induced by a Cre-mediated gene recombination, and differentiation or proliferation of the intestinal epithelial cells was examined by immunohistochemistry. These data are the extension of the data presented and discussed in the paper entitled "Indispensable role of non-canonical Notch signaling in the proliferation of Apc-deficient intestinal tumors" (Nakata et al., Submitted for publication) [1].

Temporal change of myocardial tissue character is associated with left ventricular reverse remodeling in patients with dilated cardiomyopathy: A cardiovascular magnetic resonance study

BACKGROUND

Prognostic significance of temporal change in myocardial tissue characterization by cardiovascular magnetic resonance (CMR) has not been elucidated in patients with non-ischemic dilated cardiomyopathy (DCM).

METHODS AND RESULTS

Sixty-eight patients with newly-diagnosed DCM who underwent CMR including late gadolinium enhancement (LGE) both at baseline and during follow-up period were enrolled. LGE score was defined by a signal intensity of ≥5 standard deviations above the remote reference myocardium mean. Left ventricular reverse remodeling (LVRR) defined as a LV ejection fraction increase of ≥10% and a decrease in indexed LV end-diastolic diameter of ≥10% compared to those at baseline was detected in 38% of the patients. There was no significant difference in LGE score between baseline and follow-up (5.8% vs. 7.3%; p=0.38). The change in LGE area (delta-LGE) was significantly lower in patients with LVRR than those without (-0.5%±3.4% vs. 3.0±7.4%; p=0.02). On the other hand, T2 ratio during the follow-up significantly reduced (1.95±0.48 vs. 1.67±0.56; p<0.01); however, there was no significant difference in the change in T2 ratio between patients with LVRR and those without (-0.29±0.73 vs. -0.27±0.66; p=0.88). Multivariate logistic analysis indicated that baseline LGE score [odds ratio; 0.78; 95% confidence interval (CI) 0.66 to 0.90; p<0.01] together with delta-LGE (odds ratio; 0.77; 95% CI 0.61 to 0.92; p=0.01) were independently associated with subsequent LVRR (p<0.01).

CONCLUSIONS

The temporal change of LGE-CMR score during the clinical course was significantly correlated with following LVRR.