Multiorgan Systems Study Reveals Igfbp7 as a Suppressor of Gluconeogenesis after Gastric Bypass Surgery.

Roux-en-Y gastric bypass (RYGB) surgery reduces weight in obese patients. A marked decrease in blood glucose levels occurs before weight loss; however, key molecules that improve the glycemic profile remain largely unknown. Using a murine RYGB surgery model, we performed multiorgan proteomics and bioinformatics to monitor the proteins and molecular pathways that change in this early glycemic response. Multiplexed proteomic kinetics data analysis revealed that the Roux limb, biliopancreatic limb, liver, and pancreas each exhibited unique temporal and molecular responses to the RYGB surgery. In addition, protein-protein network analysis indicated that the changes to the microbial environment in the intestine may play a crucial role in the beneficial effects of RYGB surgery. Furthermore, insulin-like growth factor binding protein 7 (Igfbp7) was identified as an early induced protein in the Roux limb. Known secretory properties of Igfbp7 prompted us to further investigate its role as a remote organ regulator of glucose metabolism. Igfbp7 overexpression decreased blood glucose levels in diet-induced obese mice and attenuated gluconeogenic gene expression in the liver. Secreted Igfbp7 appeared to mediate these beneficial effects. These results demonstrate that organs responded differentially to RYGB surgery and indicate that Igfbp7 may play an important role in improving blood glucose levels.

Change in body composition in patients with achalasia before and after peroral endoscopic myotomy.

BACKGROUND AND AIM: Patients with achalasia experience weight loss because of dysphagia caused by impaired relaxation of the lower esophageal sphincter. This study aimed to use dual bioelectrical impedance analysis (BIA) to determine the change in bodyweight and body composition in patients with achalasia before and after peroral endoscopic myotomy (POEM). METHODS: Patients with achalasia who underwent POEM from 2013 to 2018 (n = 72) were retrospectively analyzed for change in bodyweight before and after 3 months. Additionally, change in body composition was prospectively investigated in the final 10 of 72 patients using non-radiation dual BIA. RESULTS: Twenty patients (27.8%) were underweight (body mass index < 18.5) before undergoing POEM. No clinical parameters were identified to be associated with the underweight condition before POEM and be predictive of an increase in bodyweight after POEM. Low visceral fat volume observed on dual BIA correlated closely with the result obtained using computed tomography (Pearson correlation coefficient: r = 0.850, P < 0.01). Patients with achalasia had a statistically significant increase in visceral (P < 0.01) and subcutaneous fat volumes (P < 0.01) after POEM. Skeletal muscle mass index slightly increased (P = 0.02), although the value after POEM was still low. No blood biomarkers were indicators for low bodyweight or low visceral fat volume. CONCLUSIONS: Dual BIA is an effective non-invasive tool to evaluate the change in body composition of underweight patients with achalasia. Skeletal muscle volume was not enough after POEM, although a rapid increase in the intra-abdominal fat volume was observed. Additional studies are warranted to understand the pathological implications.

Dimerization of sortilin regulates its trafficking to extracellular vesicles.

Extracellular vesicles (EVs) play a critical role in intercellular communication by transferring microRNAs, lipids, and proteins to neighboring cells. Sortilin, a sorting receptor that directs target proteins to the secretory or endocytic compartments of cells, is found in both EVs and cells. In many human diseases, including cancer and cardiovascular disorders, sortilin expression levels are atypically high. To elucidate the relationship between cardiovascular disease, particularly vascular calcification, and sortilin expression levels, we explored the trafficking of sortilin in both the intracellular and extracellular milieu. We previously demonstrated that sortilin promotes vascular calcification via its trafficking of tissue-nonspecific alkaline phosphatase to EVs. Although recent reports have noted that sortilin is regulated by multiple post-translational modifications, the precise mechanisms of sortilin trafficking still need to be determined. Here, we show that sortilin forms homodimers with an intermolecular disulfide bond at the cysteine 783 (Cys783) residue, and because Cys783 can be palmitoylated, it could be shared via palmitoylation and an intermolecular disulfide bond. Formation of this intermolecular disulfide bond leads to trafficking of sortilin to EVs by preventing palmitoylation, which further promotes sortilin trafficking to the Golgi apparatus. Moreover, we found that sortilin-derived propeptide decreased sortilin homodimers within EVs. In conclusion, sortilin is transported to EVs via the formation of homodimers with an intermolecular disulfide bond, which is endogenously regulated by its own propeptide. Therefore, we propose that inhibiting dimerization of sortilin acts as a new therapeutic strategy for the treatment of EV-associated diseases, including vascular calcification and cancer.

Overlap in disease concept of functional esophageal disorders and minor esophageal motility disorders.

BACKGROUND AND AIM: Functional gastrointestinal disorders are the most common disorders in gastroenterology and are currently considered as gut-brain interaction disorders with multiple related factors including motility disturbance. However, high-resolution manometry (HRM) had revealed a new disease concept known as minor esophageal motility disorders. This study aimed to investigate the correlation between functional esophageal disorders (FEDs) and minor esophageal motility disorders. METHODS: Functional esophageal disorders were diagnosed using upper endoscopy, pH monitoring, and HRM, to exclude achalasia, esophago-gastric junction outflow obstruction, and other major esophageal motility disorders. FEDs with or without minor esophageal motility disorders were compared using the Chicago classification. RESULTS: Twelve healthy volunteers also subjected to HRM showed no minor esophageal motility disorders. Of the 40 patients with FEDs, 15 (37.5%) were diagnosed with minor esophageal motility disorders. Characteristics were not different between patients with and without minor esophageal motility disorders (sex: P = 0.609, age: P = 0.054, body mass index: P = 0.137, and presence of psychiatric disorders: P = 0.404). The type and location of symptoms were not related to the comorbidity rate of minor esophageal motility disorders (P = 0.744 and 0.094). No patients with FEDs developed major esophageal motility disorders. CONCLUSIONS: Minor esophageal motility disorders were frequently observed in FEDs, but the causal relationship between esophageal symptoms remains unclear. The disease concepts of FEDs and minor esophageal motility disorders are considered to overlap and are both independent of major esophageal motility disorders.

Recombination-restarted replication makes inverted chromosome fusions at inverted repeats.

Impediments to DNA replication are known to induce gross chromosomal rearrangements (GCRs) and copy-number variations (CNVs). GCRs and CNVs underlie human genomic disorders and are a feature of cancer. During cancer development, environmental factors and oncogene-driven proliferation promote replication stress. Resulting GCRs and CNVs are proposed to contribute to cancer development and therapy resistance. When stress arrests replication, the replisome remains associated with the fork DNA (stalled fork) and is protected by the inter-S-phase checkpoint. Stalled forks efficiently resume when the stress is relieved. However, if the polymerases dissociate from the fork (fork collapse) or the fork structure breaks (broken fork), replication restart can proceed either by homologous recombination or microhomology-primed re-initiation. Here we ascertain the consequences of replication with a fork restarted by homologous recombination in fission yeast. We identify a new mechanism of chromosomal rearrangement through the observation that recombination-restarted forks have a considerably high propensity to execute a U-turn at small inverted repeats (up to 1 in 40 replication events). We propose that the error-prone nature of restarted forks contributes to the generation of GCRs and gene amplification in cancer, and to non-recurrent CNVs in genomic disorders.

Management decision based on lymphovascular involvement leads to favorable outcomes after endoscopic treatment of esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) invading the muscularis mucosae (MM) and submucosa up to 200 µm (SM1) has a risk of metastasis. The aims of this study were to investigate the long-term outcome of endoscopic submucosal dissection (ESD) for MM/SM1 ESCC and to assess the management after ESD in our hospital. METHODS: This was a retrospective cohort study conducted at a single institution. Patients with MM or SM1 ESCC who were treated with ESD were included. Additional prophylactic therapy was added if lymphovascular involvement (LVI) was noted in the ESD specimens. RESULTS: A total of 102 patients were analyzed. The median length of follow-up was 71.5 months (range 9 - 144 months) and the median number of CTs was 6 (range 0 - 24). LVI was found in 21 patients (20.6 %), and 12 patients underwent additional prophylactic therapy. The 5-year overall survival, disease-specific survival, and tumor-free survival rates were 84.1 %, 97.5 %, and 82.1 %, respectively. A total of 26 patients died, but only 2 of them died from ESCC. The cumulative metastasis rate was 11.8 %, and LVI was a significant predictor of metastasis (hazard ratio 5.42, 95 % confidence interval 1.39 - 21.18; P = 0.02). There were no differences between patients with MM ESCC and those with SM1 ESCC. CONCLUSIONS: The long-term outcome after ESD for MM/SM1 ESCC was favorable with additional prophylactic therapy and strict adherence to follow-up. These results indicate that our management decision based on LVI is a valid approach and that ESD can be offered as a therapeutic option to MM/SM1 ESCCs.

Design, synthesis and pharmacology of aortic-selective acyl-CoA: Cholesterol O-acyltransferase (ACAT/SOAT) inhibitors.

We describe our molecular design of aortic-selective acyl-coenzyme A:cholesterol O-acyltransferase (ACAT, also abbreviated as SOAT) inhibitors, their structure-activity relationships (SARs) and their pharmacokinetic (PK) and pharmacological profiles. The connection of two weak ligands-N-(2,6-diisopropylphenyl)acetamide (50% inhibitory concentration [IC50] = 8.6 µM) and 2-(methylthio)benzo[d]oxazole (IC50 = 31 µM)-via a linker comprising a 6 methylene group chains yielded a highly potent molecule, 9-(benzo[d]oxazol-2-ylthio)-N-(2,6-diisopropylphenyl)nonanamide (3h) that exhibited high potency (IC50 = 0.004 µM) toward aortic ACAT. This head-to-tail design made it possible to markedly enhance the activity to 2150- to 7750-fold and to discriminate the isoform-selectivity based on the double-induced fit mechanism. At doses of 1 and 3 mg/kg, 3h significantly decreased the lipid-accumulation areas in the aortic arch to 74 and 69%, respectively without reducing the plasma total cholesterol level in high fat- and cholesterol-fed F1B hamsters. Here, we demonstrate the antiatherosclerotic effect of 3hin vivo via its direct action on aortic ACAT and its powerful modulator of cholesterol level. This molecule is a potential therapeutic agent for the treatment of diseases involving ACAT-1 overexpression.

Homologous recombination restarts blocked replication forks at the expense of genome rearrangements by template exchange.

Template switching induced by stalled replication forks has recently been proposed to underlie complex genomic rearrangements. However, the resulting models are not supported by robust physical evidence. Here, we analyzed replication and recombination intermediates in a well-defined fission yeast system that blocks replication forks. We show that, in response to fork arrest, chromosomal rearrangements result from Rad52-dependent nascent strand template exchange occurring during fork restart. This template exchange occurs by both Rad51-dependent and -independent mechanisms. We demonstrate that Rqh1, the BLM homolog, limits Rad51-dependent template exchange without affecting fork restart. In contrast, we report that the Srs2 helicase promotes both fork restart and template exchange. Our data demonstrate that template exchange occurs during recombination-dependent fork restart at the expense of genome rearrangements.

Long-term outcomes of colorectal endoscopic submucosal dissection in elderly patients.

BACKGROUND AND AIMS: The safety and efficacy of endoscopic submucosal dissection (ESD) in elderly patients remain unclear. The aim of this study is to clarify the short- and long-term outcomes of colorectal ESD in elderly patients. PATIENTS AND METHODS: A total of 482 consecutive patients with 501 colorectal lesions treated with ESD from February 2005 to December 2013 were retrospectively reviewed. Patients were divided into two groups: an elderly group (≥ 75 years of age) and a non-elderly group (< 75 years of age). Short-term outcomes of interest were procedure time, complication rate, hospital stay, en bloc resection rate, and non-curative resection rate. Long-term outcomes of interest were disease-specific survival, and overall survival rates in the elderly group (51 patients) and non-elderly group (92 patients) were also analyzed. RESULTS: No significant differences were observed between the groups with respect to short-term outcomes. Two patients in each group required emergency surgery. Of the patients who underwent non-curative resection, 7/12 (58%) in the elderly group and 15/23 (65%) in the non-elderly group underwent additional surgery. The 5-year disease-specific survival rates in the elderly and non-elderly groups were both 100%, and the corresponding 5-year overall survival rates were 86.3 and 93.5%, respectively (p = 0.026). CONCLUSIONS: Short-term outcomes after colorectal ESD were equivalent in both groups, and all patients showed favorable long-term outcomes. Considering the benign prognosis of lesions resected with ESD, preoperative screening of comorbidities is essential to improve overall survival.

Safety of unsedated PEG placement using transoral ultrathin endoscopy in patients with amyotrophic lateral sclerosis.

BACKGROUND AND AIMS: In patients with amyotrophic lateral sclerosis (ALS), percutaneous endoscopic gastrostomy (PEG) placement under sedation often causes apnea or hypoventilation. The aim of the present study was to assess whether unsedated PEG placement in ALS patients using ultrathin endoscopy (UTE) via the transoral route can improve safety. METHODS: Between 2003 and 2013, PEG placement was identified and reviewed in 45 patients with ALS. PEG was performed in 14 patients using transoral UTE without sedation (UTE group), 17 patients using conventional normal-diameter esophagogastroduodenoscopy (C-EGD) without sedation (unsedated C-EGD group) and 14 patients using C-EGD with sedation (sedated C-EGD group). We compared the clinical features, cardiopulmonary data before and during PEG placement, and complications related to PEG placement among the three groups. RESULTS: There were no significant differences in age, male/female ratio, forced vital capacity, blood pressure, oxygen saturation before and during PEG, or major complications among the three groups. No minor complications were observed in the UTE group, whereas apnea and/or hypoventilation were observed in the sedated C-EGD group and aspiration pneumonia was observed in the unsedated C-EGD group. CONCLUSIONS: Unsedated PEG placement using transoral UTE in ALS patients is a safe method.

Nearby inverted repeats fuse to generate acentric and dicentric palindromic chromosomes by a replication template exchange mechanism.

Gene amplification plays important roles in the progression of cancer and contributes to acquired drug resistance during treatment. Amplification can initiate via dicentric palindromic chromosome production and subsequent breakage-fusion-bridge cycles. Here we show that, in fission yeast, acentric and dicentric palindromic chromosomes form by homologous recombination protein-dependent fusion of nearby inverted repeats, and that these fusions occur frequently when replication forks arrest within the inverted repeats. Genetic and molecular analyses suggest that these acentric and dicentric palindromic chromosomes arise not by previously described mechanisms, but by a replication template exchange mechanism that does not involve a DNA double-strand break. We thus propose an alternative mechanism for the generation of palindromic chromosomes dependent on replication fork arrest at closely spaced inverted repeats.

New CETP inhibitor K-312 reduces PCSK9 expression: a potential effect on LDL cholesterol metabolism.

Despite significant reduction of cardiovascular events by statin treatment, substantial residual risk persists, driving emerging needs for the development of new therapies. We identified a novel cholesteryl ester transfer protein (CETP) inhibitor, K-312, that raises HDL and lowers LDL cholesterol levels in animals. K-312 also suppresses hepatocyte expression of proprotein convertase subtilisin/kexin 9 (PCSK9), a molecule that increases LDL cholesterol. We explored the underlying mechanism for the reduction of PCSK9 expression by K-312. K-312 inhibited in vitro human plasma CETP activity (IC50; 0.06 µM). Administration of K-312 to cholesterol-fed New Zealand White rabbits for 18 wk raised HDL cholesterol, decreased LDL cholesterol, and attenuated aortic atherosclerosis. Our search for additional beneficial characteristics of this compound revealed that K-312 decreases PCSK9 expression in human primary hepatocytes and in the human hepatoma cell line HepG2. siRNA silencing of CETP in HepG2 did not compromise the suppression of PCSK9 by K-312, suggesting a mechanism independent of CETP. In HepG2 cells, K-312 treatment decreased the active forms of sterol regulatory element-binding proteins (SREBP-1 and -2) that regulate promoter activity of PCSK9. Chromatin immunoprecipitation assays demonstrated that K-312 decreased the occupancy of SREBP-1 and SREBP-2 on the sterol regulatory element of the PCSK9 promoter. PCSK9 protein levels decreased by K-312 treatment in the circulating blood of cholesterol-fed rabbits, as determined by two independent mass spectrometry approaches, including the recently developed, highly sensitive parallel reaction monitoring method. New CETP inhibitor K-312 decreases LDL cholesterol and PCSK9 levels, serving as a new therapy for dyslipidemia and cardiovascular disease.

Successful management of severe intrahepatic cholestasis of pregnancy: report of a first Japanese case.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is a cholestasis condition caused by elevated levels of serum bile acids that mainly occurs in the third trimester of pregnancy. Maternal symptoms include pruritus; elevation of transaminases, biliary enzymes, and bilirubin levels; and abnormal liver function tests. Fetal symptoms include spontaneous preterm labor, fetal distress, and intrauterine death. It is more prevalent in the Caucasians and is rarely found in Asian countries, including Japan. The etiology of ICP has been reported as involving various factors such as, environmental factors, hormone balance, and genetic components. The genetic factors include single-nucleotide polymorphisms (SNPs) in the genes of canalicular transporters, including ABCB4 and ABCB11. It has also been reported that the combination of these SNPs induces severe cholestasis and liver dysfunction. CASE PRESENTATION: Here, we report for the first time a 24-year Japanese case of severe ICP diagnosed by typical symptoms, serum biochemical analysis, and treated with the administration of ursodeoxycholic acid which improved cholestasis and liver injury and prevented fetal death. The sequence analysis showed SNPs reported their association with ICP in the ABCB11 (rs2287622, V444A) and ABCB4 (rs1202283, N168N) loci. CONCLUSION: The risk of ICP has been reported to be population-specific, and it is rare in the Japanese population. Our case was successfully treated with ursodeoxycholic acid and the genetic sequence analysis has supported the diagnosis. Because genetic variation in ABCB4 and ABCB11 has also been reported in the Japanese population, we need to be aware of potential ICP cases in pregnant Japanese women although further studies are necessary.

Granulocytapheresis for the treatment of severe alcoholic hepatitis: a case series and literature review.

Severe alcoholic hepatitis has a high mortality rate due to limited therapeutic methods. Although corticosteroids have been used to control the inflammatory response, the outcomes vary and no standardized therapy has been established. Novel therapeutic approaches, such as anti-TNF-α, pentoxifilline, and others have been tested clinically on the basis of their cytokinemic pathophysiology with limited success. However, treatment of leukocytosis that causes cytokinemia and hepatic inflammation in patients via granulocytapheresis and leukocytapheresis showed promising results in a number of reports. Here, we report two cases of severe alcoholic hepatitis treated with granulocytapheresis. The liver function and inflammation recovered after the therapy. A review of 35 cases treated with granulocytapheresis and leukocytapheresis demonstrated their efficacy in treating alcoholic hepatitis by controlling leukocytosis as well as cytokines such as IL-8. Multidisciplinary treatment for severe alcoholic hepatitis should be considered case by case on the basis of the complexity and severity of the condition.

Natural history of diminutive colorectal polyps: long-term prospective observation by colonoscopy.

BACKGROUND AND AIM: Endoscopic removal of colorectal adenomatous polyps effectively prevents cancer. However, the treatment strategy for diminutive polyps (diameter ≤ 5 mm) remains controversial. Understanding the natural history of diminutive polyps is a prerequisite to their effective management. We prospectively examined the natural history of diminutive polyps by long-term surveillance colonoscopy. METHODS: A total of 207 polyps detected in 112 patients from December 1991 through March 2002 were studied. To avoid potential effects on size and morphological characteristics, all polyps were selected randomly and were followed without biopsy. Polyp size was estimated by comparing the lesion with the diameter of a biopsy forceps. RESULTS: Mean follow up was 7.8 years (SD, 4.8; range, 1.0-18.6; median, 7.5; interquartile range 3.4-11.2). Twenty-four polyps were resected endoscopically, and the histopathological diagnosis was mucosal high-grade neoplasia (Category 4) for one polyp, and mucosal low-grade neoplasia (Category 3) for 23 polyps. Mean linear size of the polyps was 3.2 mm (SD, 1.0; range, 1.3-5.0) at initial colonoscopy and 3.8 mm (SD 1.6; range 1.3-10.0) at final colonoscopy (P<0.01). Left-sided polyps showed a higher growth rate than right-sided polyps, and a type IIIL2 pit pattern was associated with a lower growth rate than a type IIIL1 pattern. CONCLUSION: We clarified the natural history of diminutive polyps by long-term follow-up colonoscopy. The benign course of diminutive polyps should be considered in the design of treatment strategies.

Smc5/6 maintains stalled replication forks in a recombination-competent conformation.

The Smc5/6 structural maintenance of chromosomes complex is required for efficient homologous recombination (HR). Defects in Smc5/6 result in chromosome mis-segregation and fragmentation. By characterising two Schizosaccharomyces pombe smc6 mutants, we define two separate functions for Smc5/6 in HR. The first represents the previously described defect in processing recombination-dependent DNA intermediates when replication forks collapse, which leads to increased rDNA recombination. The second novel function defines Smc5/6 as a positive regulator of recombination in the rDNA and correlates mechanistically with a requirement to load RPA and Rad52 onto chromatin genome-wide when replication forks are stably stalled by nucleotide depletion. Rad52 is required for all HR repair, but Rad52 loading in response to replication fork stalling is unexpected and does not correlate with damage-induced foci. We propose that Smc5/6 is required to maintain stalled forks in a stable recombination-competent conformation primed for replication restart.

Salvage endoscopic submucosal dissection in patients with local failure after chemoradiotherapy for esophageal squamous cell carcinoma.

OBJECTIVE: For locoregional failure after chemoradiotherapy (CRT) in patients with esophageal squamous cell carcinoma (ESCC), salvage esophagectomy and endoscopic mucosal resection have disadvantages, such as a high morbidity rate and a high local recurrence rate, respectively. The aim of this study was to clarify the efficacy of salvage endoscopic submucosal dissection (ESD) for locoregional failure of CRT. METHODS: A total of 19 lesions in 19 patients were treated with salvage ESD; 15 lesions were local recurrences at the primary site and 4 lesions were residual. All lesions were intramucosal or submucosal tumors without metastases. A case-control study was retrospectively evaluated to clarify whether the clinical outcomes of salvage ESD were equivalent to those of control primary ESD. RESULTS: No significant differences were observed between salvage ESD and primary ESD in short-term outcomes, including procedure time. For salvage ESD, the complete en bloc resection rate was 94.7% (18 of 19), and no severe complications were observed. At a median follow up of 54.6 (range: 5-98) months after salvage ESD, the local recurrence rate was 0%. However, three patients (15.8%) died due to lymph node and distant metastases and six patients (31.5%) died from other diseases, including radiation pneumonitis, pyothorax or respiratory failure with no recurrence of ESCC. The 3-year overall survival rate for all 19 patients was 74%. CONCLUSIONS: ESD represents an acceptable treatment option for recurrent or residual ESCC because of its improvement in local control, when local failure after CRT is limited to the submucosal layer without metastases.

Usefulness of endoscopic submucosal dissection for type I gastric carcinoid tumors compared with endoscopic mucosal resection.

BACKGROUND/AIMS: Gastric carcinoid tumors (GCTs) often extends into the submucosa, and are therefore difficult to resect completely by using conventional endoscopic mucosal resection (EMR). Endoscopic submucosal dissection (ESD) allows en bloc resection of submucosal gastrointestinal lesions. Therefore, ESD may be a feasible method for complete resection of GCT. Our purpose is to clarify the usefulness of ESD for treatment of type I GCT. METHODOLOGY: Between 1998 and 2011, EMR or ESD was performed for 13 lesions in 12 patients with type I GCTs. Among the 13 GCTs, 6 were resected using EMR, and 7 were removed using ESD. RESULTS: All lesions were histologically classified as Grade 1. The depth of invasion was the mucosa for 1 lesion and the submucosa for 12 lesions. The horizontal margins of excision were negative for all lesions; however, the vertical margins were positive in 4 lesions (66.7%) in the EMR group and no lesions (0%) in the ESD group. CONCLUSIONS: The results of this study suggest that ESD for small type I GCT is better to achieve complete resection than conventional EMR. ESD would be an effective technique for the treatment of small type I GCT.