The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

The Chemical Chaperone 4-Phenylbutyric Acid Prevents Alcohol-Induced Liver Injury in Obese KK-Ay Mice

BACKGROUND

Co-occurrence of metabolic syndrome and chronic alcohol consumption is increasing worldwide. The present study investigated the effect of the chemical chaperone 4-phenylbutyric acid (PBA)-which has been shown to alleviate dietary steatohepatitis caused by endoplasmic reticulum (ER) stress-on chronic-plus-binge ethanol (EtOH)-induced liver injury in a mouse model of obesity.

METHODS

Male KK-A^y mice (8 weeks old) were fed a Lieber-DeCarli diet (5% EtOH) for 10 days. Some mice were given PBA intraperitoneally (120 mg/kg body weight, daily) during the experimental period. On day 11, mice were gavaged with a single dose of EtOH (4 g/kg body weight). Control mice were given a dextrin gavage after being pair-fed a control diet. All mice were then serially euthanized before or at 9 hours after gavage.

RESULTS

Chronic-plus-binge EtOH intake induced massive hepatic steatosis along with hepatocyte apoptosis and inflammation, which was reversed by PBA treatment. Administration of PBA also suppressed chronic-plus-binge EtOH-induced up-regulation of ER stress-related genes including binding immunoglobulin protein (Bip), unspliced and spliced forms of X-box-binding protein-1 (uXBP1 and sXBP1, respectively), inositol trisphosphate receptor (IP3R), and C/EBP homologous protein (CHOP). Further, it blocked chronic-plus-binge EtOH-induced expression of the oxidative stress marker heme oxygenase-1 (HO-1) and 4-hydroxynonenal. Chronic EtOH alone (without binge) increased Bip and uXBP1, but it did not affect those of sXBP1, IP3R, CHOP, or HO-1. PBA reversed the prebinge expression of these genes to control levels, but it did not affect chronic EtOH-induced hepatic activity of cytochrome P450 2E1.

CONCLUSIONS

Binge EtOH intake after chronic consumption induces massive ER stress-related oxidative stress and liver injury in a mouse model of obesity through dysregulation of the unfolded protein response. PBA ameliorated chronic-plus-binge EtOH-induced liver injury by reducing ER and oxidative stress after an EtOH binge.

A prospective randomized trial of a potassium competitive acid blocker vs proton pump inhibitors on the effect of ulcer healing after endoscopic submucosal dissection of gastric neoplasia

Background/Aims

Vonoprazan is a new a potassium-competitive acid blocker (P-CAB) that was recently developed in Japan. However, vonoprazan’s efficacy in healing gastric ulcers after endoscopic submucosal dissection (ESD) remains controversial. This study aimed to compare the efficacy of P-CABs and proton pump inhibitors (PPIs) in healing post-ESD ulcers.

Materials and Methods

This prospective randomized controlled trial (UMIN000017386) enrolled 40 patients with gastric neoplasia, who underwent ESD at our hospital from April 2015 to January 2016. Before ESD, patients were randomly divided into the following two groups: group V, vonoprazan 20 mg/day; or group R, rabeprazole 10 mg/day. Medications were taken 1 day before to 4 weeks after ESD. The ESD-induced artificial ulcer size was measured just after ESD and 4 weeks after ESD to calculate the reduction rate as follows: (ulcer area 4 weeks after ESD)/(ulcer area just after ESD) × 100.

Results

Eighteen patients in group V and 15 patients in group R were analyzed. The mean reduction rate was significantly different in groups V and R (93.3% vs 96.6%, respectively). Post-ESD bleeding was observed in two patients in group R and drug-induced hepatic injury in one patient in group R.

Conclusion

Rabeprazole facilitated the healing process post-ESD.

Cathepsin L-deficiency enhances liver regeneration after partial hepatectomy

AIM

Cathepsin L (Ctsl) plays a pivotal role in lysosomal and autophagic proteolysis. Previous investigations revealed that partial hepatectomy (PH) decreases biosynthesis of cathepsins in liver, followed by suppression of lysosomal and autophagic proteolysis during liver regeneration. Conversely, it was reported that autophagy-deficiency suppressed liver regeneration. Thus, the purpose of this study is to determine if Ctsl deficiency affects liver regeneration after PH.

METHODS

70% of PH was performed in male Ctsl-deficient mice (Ctsl-/-) and wild-type littermates (Ctsl +/+) after PH. Mice were sacrificed and wet weight of the whole remaining liver was measured. Bromodeoxyuridine (BrdU)-immunostaining of liver sections was performed. Expression of cyclin D1, p62, LC-3, Nrf2, cleaved-Notch1, Hes1 was evaluated by western blot analysis. NQO1 mRNA expression was measured by realtime-PCR.

RESULTS

After a 70% of PH, the liver mass was significantly restored within 5 days in Ctsl-/- mice compared to wild-type. Ctsl-deficiency enhanced the increases in both the rate of BrdU-positive cells and cyclin D1 expression after PH more than wild-type mice. On the other hand, Ctsl-deficiency upregulated p62, cleaved-Notch1 and Hes1 expression after PH. Moreover, the protein level of Nrf2 in the nucleus and mRNA expression of NQO1 in the liver after PH was also up-regulated in Ctsl-/- mice.

CONCLUSIONS

These findings suggest that accumulation of p62 due to loss of Ctsl plays an important role in liver regeneration through activation of Nrf2-Notch1 signaling. Taken together, Ctsl might be a new therapeutic target on disorder of liver regeneration.

Usefulness of Demarcation of Differentiated-Type Early Gastric Cancers after Helicobacter pylori Eradication by Magnifying Endoscopy with Narrow-Band Imaging

BACKGROUND/AIMS

Early gastric cancer after Helicobacter pylori (Hp) eradication is difficult to demarcate. We used the vessel plus surface classification system (VSCS) to determine whether magnifying endoscopy with narrow-band imaging (ME-NBI) could demarcate differentiated-type early gastric cancers after Hp eradication, and to identify causes of an unclear demarcation line (DL).

METHODS

Among 100 lesions of differentiated-type early gastric cancer resected endoscopically, 34 lesions in the Hp-eradicated group and 66 in the Hp-infected group were retrospectively compared. Clinicopathological factors and ME-NBI findings, including the presence or absence of the DL, were examined. Histopathologically, histological gastritis, the surface structure at the tumor border, well-differentiated adenocarcinoma with low-grade atypia (tub1-low), and non-neoplastic epithelium (NE) coverage rate on the tumor surface and at the tumor border were evaluated.

RESULTS

DL (-) cases were more frequent in the Hp-eradicated group (11.8%, 4/34) than in the Hp-infected group (1.5%, 1/66; p < 0.05). The Hp-eradicated group had a higher NE coverage rate than the Hp-infected group (p < 0.05). All DL (-) cases had tub1-low or NE at the tumor border.

CONCLUSION

ME-NBI with VSCS can identify the DL in most patients (88.2%) with differentiated-type early gastric cancer after Hp eradication.

TP53 inactivation and expression of methylation-associated proteins in gastric adenocarcinoma with enteroblastic differentiation

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare variant of aggressive adenocarcinoma. We demonstrated previously that GAED is genetically characterized by frequent TP53 mutation. In this study, we aimed to further clarify the mechanism of inactivation of TP53 in GAED in the light of promoter methylation of TP53, and expression of methylation-associated proteins such as Ten-eleven translocation (TET) 1 and 5-hydroxymethylcytosine (5-hmc) in addition to ATM mutations. We analyzed 51 cases of GAED. The ATM mutation was detected in only one case. Promoter methylation of TP53 was detected in 18% and frequency of loss of heterozygosity (LOH) at TP53 locus was 37.2%. Reduced TET1 expression was found in 29 cases (56.9%) and was significantly associated with advanced stage (p = 0.01), lymph node metastasis (p = 0.04), and macroscopic type (p = 0.01). Reduced 5-hmc expression was found in 28 cases (54.9%) and was significantly associated with advanced stage (p = 0.01), gender (p = 0.01), tumor location (p = 0.03), tumor size (p = 0.01), and lymph node metastasis (p = 0.01). Among 9 cases with TP53 promoter methylation, reduced expression of TET1 was observed in 6 cases, and reduced expression of 5-hmc was observed in 5 cases. Reduced expression of both TET1 and 5-hmc was significantly associated with adverse clinical outcomes. In summary, promoter methylation of TP53 is partly involved in loss of p53 expression. Aberrant methylation by reduced TET1 and 5-hmc may be involved in the development of aggressive GAED.

The Microbial Composition of Bacteroidetes Species in Ulcerative Colitis Is Effectively Improved by Combination Therapy With Fecal Microbiota Transplantation and Antibiotics

BACKGROUND

We previously reported that fresh fecal microbiota transplantation (FMT) after triple-antibiotic therapy (amoxicillin, fosfomycin, and metronidazole [AFM]; A-FMT) synergistically contributed to the recovery of phylum Bacteroidetes composition associated with the endoscopic severity and treatment efficacy of ulcerative colitis (UC). Here, we performed further microbial analyses using a higher-resolution method to identify the key bacterial species in UC and determine whether viable Bacteroidetes species from donor feces were successfully colonized by A-FMT.

METHODS

The taxonomic composition of Bacteroidetes in 25 healthy donors and 27 UC patients at baseline was compared at the species level using a heat-shock protein (hsp) 60-based microbiome method. Microbiota alterations before and after treatment of UC patients were also analyzed in 24 cases (n = 17 A-FMT; n = 3 mono-AFM; n = 4 mono-FMT).

RESULTS

We found species-level dysbiosis within the phylum Bacteroidetes in UC samples, which was associated with reduced species diversity, resulting from hyperproliferation and hypoproliferation of particular species. Moreover, in responders treated with A-FMT, diversity was significantly recovered at 4 weeks after a fresh round of FMT, after which high degrees of similarity in Bacteroidetes species composition among recipients and donors were observed.

CONCLUSIONS

A-FMT alleviated intestinal dysbiosis, which is caused by the loss of Bacteroidetes species diversity in patients with UC. Eradication of dysbiotic indigenous Bacteroidetes species by AFM pretreatment might promote the colonization of viable Bacteroidetes cells, thereby improving the intestinal microbiota dysbiosis induced by UC. Our findings serve as a basis for further investigations into the mechanisms of FMT.

Improved Visibility of Barrett's Esophagus with Linked Color Imaging: Inter- and Intra-Rater Reliability and Quantitative Analysis

BACKGROUND/AIMS

To evaluate the usefulness of linked color imaging (LCI) and blue LASER imaging (BLI) in Barrett's esophagus (BE) compared with white light imaging (WLI).

METHODS

Five expert and trainee endoscopists compared WLI, LCI, and BLI images obtained from 63 patients with short-segment BE. Physicians assessed visibility as follows: 5 (improved), 4 (somewhat improved), 3 (equivalent), 2 (somewhat decreased), and one (decreased). Scores were evaluated to assess visibility. The inter- and intra-rater reliability (intra-class correlation coefficient) of image assessments were also evaluated. Images were objectively evaluated based on L* a* b* color values and color differences (ΔE*) in a CIELAB color space system.

RESULTS

Improved visibility compared with WLI was achieved for LCI: 44.4%, BLI: 0% for all endoscopists; LCI: 55.6%, BLI: 1.6% for trainees; and LCI: 47.6%, BLI: 0% for experts. The visibility score of trainees compared with experts was significantly higher for LCI (p = 0.02). Intra- and inter-rater reliability ratings for LCI compared with WLI were "moderate" for trainees, and "moderate-substantial" for experts. The ΔE* revealed statistically significant differences between WLI and LCI.

CONCLUSION

LCI improved the visibility of short-segment BE compared with WLI, especially for trainees, when evaluated both subjectively and objectively.

Formation of p62-positive inclusion body is associated with macrophage polarization in non-alcoholic fatty liver disease

AIM

Hepatic inclusion composed of autophagy-specific substrate p62 is one of the histological features of non-alcoholic fatty liver disease (NAFLD) and can be a precursor to hepatic carcinogenesis. The expression of p62 was enhanced by not only autophagic dysfunction but also oxidative stress and inflammation. M1/M2 phenotypic balance of macrophages plays a pivotal role in the progression of NAFLD. We evaluated the correlation between macrophage polarization and the formation of p62 aggregation in NAFLD.

METHODS

Liver biopsy specimens from NAFLD patients were analyzed by immunohistochemical staining for M1 macrophage marker CD11c, M2 macrophage marker CD163, and p62/SQSTM1 (p62). The histological severity of NAFLD is assessed by a NAFLD activity score (NAS). The number of autophagic vesicles in hepatocytes was visualized and counted by using transmission electron microscopy.

RESULTS

The aggregation of p62 was undetectable in control, whereas hepatocytes with p62 aggregation were observed in approximately 88% of NAFLD specimens. The number of hepatocytes with p62 aggregation was positively correlated with the number of autophagic vesicles, serum alanine aminotransferase, NAS, fibrosis, and the number of CD11c-positive cells, but not CD163-positive cells. Assembly of CD11c-positive cells was observed around hepatocytes with p62 aggregation. The ratio of CD11c/CD163-positive macrophages was significantly associated with the formation of p62 aggregation.

CONCLUSIONS

These findings indicate that chronic inflammation by M1-polarization of macrophages contributes to the disease progression from simple steatosis to non-alcoholic steatohepatitis in concert with autophagic dysfunction.