Clinical impact of pancreatic steatosis measured by CT on the risk of post-ERCP pancreatitis: a multicenter prospective trial.

BACKGROUND AND AIMS: Pancreatic steatosis (PS) may be a risk factor for acute pancreatitis. Whether it is also a risk factor for post-ERCP pancreatitis (PEP) has not been evaluated. This study aimed to determine the impact of PS on PEP development. METHODS: This multicenter prospective trial enrolled 786 consecutive patients who underwent contrast-enhanced abdominal CT and subsequent first-time ERCP. PS was evaluated based on pancreatic attenuation on unenhanced CT images. The risk of PS for the development of PEP was evaluated using a logistic regression model. RESULTS: Of 527 patients included in the study, 157 (29.8%) had PS and 370 (70.2%) did not. At 24 hours after ERCP, there was a significant difference in the PEP identified in 22 patients (14.0%) in the PS group and 23 patients (6.2%) in the "no PS" (NPS) group (P = .017). Diabetes and hypertension were more common in the PS group than in the NPS group; no differences in dyslipidemia were found. Patients with PS had a higher risk for the development of PEP than those with NPS (odds ratio, 2.09; 95% confidence interval, 1.08-4.03). No other variables were identified as risk factors for PEP. CONCLUSIONS: PS is a significant risk factor for PEP for which preventive measures should be considered. Standardized measurement protocols to assess PS by CT are needed. (Clinical trial registration number: KCT0006068.).

Evaluation on the Sex-Specific Association Between Cigarette Smoke Exposure and Inflammation Markers-C-Reactive Protein and White Blood Cell Count.

INTRODUCTION: Cigarette smoke increases peripheral white blood cell (WBC) count. However, the dose-dependent association between smoking and C-reactive protein (CRP), an important inflammatory marker, has been reported as inconsistent. AIMS AND METHODS: Here, we evaluated the associations between smoking and CRP using both smoking questionnaires and urine cotinine as exposure markers. The Korea National Health and Nutrition Examination Survey data were used for analyzing the associations. Multiple regression analyses were performed to examine the associations between cigarette smoke exposure, as assessed by questionnaires and urine cotinine, and health effects, as measured by CRP and WBC count, controlling for potential confounders. The confounders, including age, sex, body mass index, blood pressure, cholesterol, glucose, alanine aminotransferase, and uric acid, were selected a priori based on the literature. RESULTS: A total of 11 435 participants were included for analysis. For the exposure-response relationship, the results indicated a significant increase in CRP levels in male smokers compared to male nonsmokers (p = .002), whereas no significant increase was found in female smokers compared to female nonsmokers (p = .680). For the dose-response relationship, a significant positive association was observed between urine cotinine and CRP in male smokers (p = .018), whereas no significant association was found in female smokers (p = .508). WBC count consistently showed significant exposure-response and dose-response relationships in both sexes. CONCLUSIONS: WBC count was found to be a consistent effect marker of cigarette smoke exposure, while the association between CRP level and smoking was inconsistent and varied by sex. The sex-specific response to cigarette smoke exposure warrants further exploration in future studies. IMPLICATIONS: Cigarette smoke exposure is known to increase inflammation and has been thought to increase CRP, a significant inflammation marker. However, recent studies have reported conflicting results regarding the dose-dependent association between cigarette smoke exposure and CRP. This study found that the association between smoking and CRP is inconsistent and varies by sex, showing significant exposure response in men but not in women. Furthermore, the study suggests that WBC count is a more consistent marker for cigarette smoke exposure.

In Silico and In Vitro multiple analysis approach for screening naturally derived ligands for red seabream aryl hydrocarbon receptor.

The aryl hydrocarbon receptor (AHR) is a key ligand-dependent transcription factor that mediates the toxic effects of compounds such as dioxin. Recently, natural ligands of AHR, including flavonoids, have been attracting physiological and toxicological attention as they have been reported to regulate major biological functions such as inflammation and anti-cancer by reducing the toxic effects of dioxin. Additionally, it is known that natural AHR ligands can accumulate in wildlife tissues, such as fish. However, studies in fish have investigated only a few ligands in experimental fish species, and the AHR response of marine fish to natural AHR ligands of various other structures has not been thoroughly investigated. To explore various natural AHR ligands in marine fish, which make up the most fish, it is necessary to develop new screening methods that consider the specificity of marine fish. In this study, we investigated the response of natural ligands by constructing in vitro and in silico experimental systems using red seabream as a model species. We attempted to develop a new predictive model to screen potential ligands that can induce transcriptional activation of red seabream AHR1 and AHR2 (rsAHR1 and rsAHR2). This was achieved through multiple analyses using in silico/ in vitro data and Tox21 big data. First, we constructed an in vitro reporter gene assay of rsAHR1 and rsAHR2 and measured the response of 10 representatives natural AHR ligands in COS-7 cells. The results showed that FICZ, Genistein, Daidzein, I3C, DIM, Quercetin and Baicalin induced the transcriptional activity of rsAHR1 and rsAHR2, while Resveratrol and Retinol did not induce the transcriptional activity of rsAHR isoforms. Comparing the EC50 values of the respective compounds in rsAHR1 and rsAHR2, FICZ, Genistein, and Daidzein exhibited similar isoform responses, but I3C, Baicalin, DIM and Quercetin show the isoform-specific responses. These results suggest that natural AHR ligands have specific profiling and transcriptional activity for each rsAHR isoform. In silico analysis, we constructed homology models of the ligand binding domains (LBDs) of rsAHR1 and rsAHR2 and calculated the docking energies (U_dock values) of natural ligands with measured in vitro transcriptional activity and dioxins reported in previous studies. The results showed a significant correlation (R2=0.74(rsAHR1), R2=0.83(rsAHR2)) between docking energy and transcriptional activity (EC50) value, suggesting that the homology model of rsAHR1 and rsAHR2 can be utilized to predict the potential transactivation of ligands. To broaden the applicability of the homology model to diverse compound structures and validate the correlation with transcriptional activity, we conducted additional analyses utilizing Tox21 big data. We calculated the docking energy values for 1860 chemicals in both rsAHR1 and rsAHR2, which were tested for transcriptional activation in Tox21 data against human AHR. By comparing the U_dock energy values between 775 active compounds and 1085 inactive compounds, a significant difference (p<0.001) was observed between the U_dock energy values in the two groups, suggesting that the U_dock value can be applied to distinguish the activation of compounds. Furthermore, we observed a significant correlation (R2=0.45) between the AC50 of Tox21 database and U_dock values of human AHR model. In conclusion, we calculated equations to translate the results of an in silico prediction model for ligand screening of rsAHR1 and rsAHR2 transactivation. This ligand screening model can be a powerful tool to quantitatively estimate AHR transactivation of major marine agents to which red seabream may be exposed. The study introduces a new screening approach for potential natural AHR ligands in marine fish, based on homology model-docking energy values of rsAHR1 and rsAHR2, with implications for future agonist development and applications bridging in silico and in vitro data.

Cholecystectomy Increases the Risk of Type 2 Diabetes in the Korean Population: Data From the National Health Insurance Cooperation Health Checkup 2010-2017.

OBJECTIVE: This study assessed whether cholecystectomy is a risk factor for newly developed type 2 diabetes mellitus (T2DM) in the Korean population. BACKGROUND: There is a lack of evidence that cholecystectomy is independently associated with insulin resistance and T2DM. METHODS: This study included all patients aged more than 20 years who had undergone cholecystectomy from 2010 to 2015 (n=55,166) and age-matched and sex-matched control subjects without cholecystectomy (n=110,332) using the National Health Insurance Service database. They were followed up until the date of newly developed T2DM or study end and the incidence of T2DM was traced over a maximum observation period of 7 years. RESULTS: Overall, 55,166 patients who underwent cholecystectomy and 110,332 age-matched and sex-matched controls were followed up for ∼4.7 years, during which, incident T2DM occurred in 5982 (3.61%) patients. Cholecystectomy was associated with 20% higher risk of T2DM after adjustment for all covariates. The cumulative incidence of T2DM also significantly increased in the cholecystectomy group for ∼7 years ( P <0.001). The adjusted hazard ratio (HR) for T2DM was the highest in the group with both cholecystectomy and obesity using the control without both cholecystectomy and obesity as a reference [HR=1.41, 95% confidence interval (CI): 1.29-1.56]. The group with cholecystectomy without obesity showed the comparable risk of incident T2DM compared with the group without cholecystectomy with obesity (HR=1.29, 95% CI: 1.20-1.40 for cholecystectomy without obesity and HR=1.24, 95% CI: 1.14-1.36 for control with obesity). CONCLUSIONS: These results provide evidence that cholecystectomy is associated with an increased risk of newly developed T2DM in the Korean population. Further research is required to elucidate the mechanism of the association between cholecystectomy and incident diabetes.

Evaluation of Temporal Trends of Lead Exposure in Korean Workers Using Workplace Monitoring Data.

BACKGROUND: Lead, which is widely used in various industrial settings, is a major health hazard for manufacturing workers. Therefore, control of lead exposure has been implemented in an effort to prevent lead-related health problems. In this study, our aim was to evaluate temporal trends in occupational lead exposure in Korean lead workers using data from monitoring of workplace exposure. METHODS: A nationwide work environment monitoring database, data from a work environment monitoring institution, and data extracted from a review paper were utilized. Different versions of standard industrial classification codes were aligned with the 10th Korean Standard Industrial Classification, which is generally consistent with the 4th revision of the International Standard Industrial Classification. The multiple data sources were combined and temporal trends over the period from 1994-2021 were estimated. In addition, separate estimation of temporal trends in the storage battery manufacturing industry over the period from 1987-2021 was also performed. RESULTS: A total of 444,296 personal airborne lead measurements were used for the estimation process. The temporal trends in occupational exposure to lead declined by -6% annually over the study period. In particular, levels of lead exposure in the storage battery manufacturing industry showed a steeper decline of -12% annually. CONCLUSIONS: Findings of our study showed that occupational exposure to lead declined over the period from 1994 to 2021 in Korea. However, adverse effects of exposure to lead on health should be regarded with caution. The results will be useful in conduct of epidemiological studies examining lead-related effects on health.

Low insertion of cystic duct increases risk for common bile duct stone recurrence.

BACKGROUND: Common bile duct (CBD) stone is one of the most frequent biliary diseases. Recurrence after the complete removal of CBD stones is high, and we aim to evaluate the rate and risk factors for symptomatic recurrence of CBD stones after endoscopic retrograde cholangiopancreatography (ERCP). METHODS: We, retrospectively, reviewed the database of patients who underwent ERCP for CBD stones and subsequent cholecystectomy between January 2015 and December 2017 at a tertiary hospital. The recurrence of symptomatic CBD stones was defined as the presence of a CBD stone with related symptoms at least 6 months after the ERCP procedure. The primary outcomes were recurrence of symptomatic CBD stones and its risk factors. RESULTS: Among the 362 enrolled patients, 60 experienced a symptomatic recurrence of CBD stones between 6 months and 5 years after the procedure. The mean duration of follow-up was 32.3 ± 8.1 months. The patients with recurrences were older and had a longer follow-up duration. Low insertion of the cystic duct (HR = 2.893, p = 0.016), distal CBD angulation (HR = 1.015, p = 0.034), maximum CBD diameter (HR = 1.070, p = 0.012), number of ERCP sessions at first admission (HR = 1.558, p = 0.032), and cannulation time (HR = 1.030, p = 0.008) were the independent risk factors for symptomatic recurrent CBD stones. CONCLUSIONS: Patients with risk factors, especially those with low cystic duct insertion, are more prone to symptomatic recurrent CBD stones and should be followed more carefully.

Ursodeoxycholic acid shows antineoplastic effects in bile duct cancer cells via apoptosis induction; p53 activation; and EGFR-ERK, COX-2, and PI3K-AKT pathway inhibition.

Unlike in normal cells, ursodeoxycholic acid (UDCA) causes apoptosis rather than protection in cancer cells. Aim of this study was to demonstrate whether UDCA actually inhibits proliferation and induces apoptosis in bile duct cancer cells; the effect of UDCA on the expression of COX-2, PI3K/AKT, ERK, and EGFR; how UDCA affects cancer cell invasiveness and metastasis, since these effects are not established in bile duct cancer cells. SNU-245 cells (human extrahepatic bile duct cancer cells) were cultured. MTT assays were performed to evaluate the effect of UDCA on the cell proliferation. A cell death detection enzyme-linked immunosorbent assay and a caspase-3 activity assay were used to determine apoptosis. Western blot analysis measured expression levels of various proteins. The invasiveness of the cancer cells was evaluated by invasion assay. In cultured bile duct cancer cells, UDCA suppressed cell proliferation in bile duct cancer cells by inducing apoptosis and p53 activation, blocking deoxycholic acid (DCA)-induced activated EGFR-ERK signaling and COX-2, inhibiting DCA-induced activated PI3K-AKT signaling, and suppressing the invasiveness of bile duct cancer cells. In addition, a MEK inhibitor impaired UDCA-induced apoptosis in bile duct cancer cells. UDCA has antineoplastic and apoptotic effects in bile duct cancer cells. Thus, UDCA could be a chemopreventive agent in patients with a high risk of cancer, and/or a therapeutic option that enhances other chemotherapeutics.

Identification of risk factors for obstructive cholecystitis following placement of biliary stent in unresectable malignant biliary obstruction: a 5-year retrospective analysis in single center.

BACKGROUND: The risk factors for acute cholecystitis following biliary stent placement in patients with malignant biliary obstruction (MBO) have not been identified. We determined these risk factors and the efficacy of endoscopic ultrasound (EUS)-guided gallbladder drainage (GBD) as treatment. METHODS: We retrospectively analyzed patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) for MBO from October 2013 to September 2018, and those with unresectable MBO with intact gallbladder (GB) were enrolled. RESULTS: Acute cholecystitis occurred in 30 (15.7%) of 191 patients who underwent biliary stent placement for unresectable MBO. Logistic regression analysis confirmed that biliary stent across the orifice of the cystic duct (OCD) (odds ratio [OR] 6.02, 95% confidence interval [CI] 1.43-25.41, P = 0.015), GB opacification during ERCP (OR 13.07, 95% CI 4.22-40.50; P < 0.0001), and self-expandable metal stent (SEMS) (OR 14.19, 95% CI 4.36-46.18; P < 0.0001) were independent risk factors for cholecystitis. Subgroup analysis of patients who only underwent SEMS placement showed that biliary stent across the OCD and GB opacification were significant risk factors. Among the 25 patients who underwent EUS-GBD, the technical and clinical success rates were 100% and 96%, respectively. CONCLUSIONS: Biliary stent across the OCD, GB opacification, and SEMS were established as potential risk factors for post-ERCP cholecystitis. Thus, the strategy of using shorter stent length and avoiding unnecessary contrast injection could be a reasonable treatment option for selected patients with high risk of cholecystitis. Furthermore, EUS-GBD is not only safe and reliable for acute cholecystitis, but it also improves quality of life.

Effects of tris(2-chloroethyl) phosphate exposure on chicken embryos in a shell-less incubation system.

Tris(2-chloroethyl) phosphate (TCEP) is an organophosphate flame retardant that used in textiles, industrial materials, and furniture to delay the spread of fire after ignition. TCEP has been detected in the tissues and eggs of fish and birds. However, there are no studies regarding the effects of TCEP on avian embryos. In the present study, we investigated the developmental toxicity of TCEP exposure on chicken embryos in a shell-less incubation system, which enables in situ observation. Chicken embryos were treated with graded doses of TCEP (50, 250, and 500 nmol/g egg) on incubation day 0. The survival rate, morphological biometrics, heart rate, and length and branch number of extraembryonic blood vessels were measured on incubation days 3-9. Survival rates were reduced from incubation day 3 and were significantly decreased until day 9. Body length, head + bill length and eye diameter were significantly reduced by TCEP exposure. Regarding skeletal effects, spine length was decreased in a dose-dependent manner on day 9. Body weight on day 9 significantly reduced in all TCEP treatment groups. These results suggest that TCEP exposure to >50 nmol/g egg retards development in chicken embryos. TCEP exposure to 500 nmol/g egg significantly increased heart weight to body weight ratio in the embryos. More than 250 nmol/g egg of TCEP significantly reduced the heart rate of embryos in the early developmental stage. The formation of extraembryonic blood vessels and the number of erythrocytes were significantly reduced even with 50 nmol/g egg of TCEP. These findings suggest that TCEP exposure specifically affects the cardiovascular system in chicken embryos, which leads to developmental delay. The results of this study also demonstrate that the shell-less incubation system can be used to continuously monitor the effects of chemicals on developing avian embryos.

Primary Needle-Knife Fistulotomy Versus Conventional Cannulation Method in a High-Risk Cohort of Post-Endoscopic Retrograde Cholangiopancreatography Pancreatitis.

OBJECTIVES: Successful biliary cannulation is a prerequisite and important component of endoscopic retrograde cholangiopancreatography, but conventional cannulation methods (CCMs) have a postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) rate of 14.1% in patients at high risk for PEP. The aim of this study was to evaluate the effectiveness and safety of needle-knife fistulotomy (NKF), compared with a CCM, when used for primary biliary access in patients at high risk for developing PEP. METHODS: A total of 207 patients with one or more risk factors for PEP were prospectively enrolled. The patients were randomly allocated to one of 2 groups according to the primary biliary cannulation technique (NKF or CCM). We compared biliary cannulation success rates, cannulation and procedure times, and the incidence of adverse events, including PEP, between the groups. RESULTS: The mean number of PEP risk factors was similar between the groups (NKF, 2.2 ± 1.0; CCM, 2.2 ± 0.9). PEP occurred in 8 patients in the CCM group and in no patients in the NKF group (9.2% vs 0%, P < 0.001). The rates of other adverse events did not differ between the groups. The biliary cannulation success rate was high in the NKF group, but relatively low in the CCM group, possibly because of the stringent failure criteria aimed at reducing PEP. However, the mean cannulation and total procedural times were longer in the NKF group than in the CCM group. DISCUSSION: NKF is an effective and safe procedure to gain primary biliary access in patients at high risk for developing PEP. ClinicalTrials.gov, NCT02916199.

The role of linked color imaging in endoscopic diagnosis of Helicobacter pylori associated gastritis.

OBJECTIVE: Linked color imaging (LCI), a novel image-enhanced endoscopy, can make it easy to recognize differences in mucosal color. It may be helpful for diagnosing H. pylori associated gastritis and H. pylori infection status. We investigated whether LCI could improve the diagnostic accuracy of H. pylori associated gastritis. MATERIALS AND METHODS: Upper endoscopy was performed for 100 patients using white light imaging (WLI) and LCI. During the exam, endoscopic video was recorded. It was then analyzed by four expert endoscopists. They reviewed these videos for endoscopic diagnosis of atrophic gastritis, metaplastic gastritis, nodular gastritis and H. pylori infection. Tissue biopsies with rapid urease test were done to confirm H. pylori infection status and intestinal metaplasia. RESULTS: Kappa values for the inter-observer variability among the four endoscopists were fair to moderate under WLI and fair to good under LCI. Sensitivity, specificity, positive predictive value and negative predictive value for diagnosing H. pylori infection using WLI were 32.4%, 93.3%, 85.2% and 53.6%, respectively, while those for LCI were 57.4%, 91.3%, 88.7% and 64.3%, respectively. Total diagnostic accuracies for diagnosing H. pylori infection using WLI/LCI were 70.8%/78.8%. The accuracy and sensitivity of LCI for diagnosing H. pylori infection were significantly higher than those of WLI (p < .001 for both). However, there were no significant differences in the accuracy, sensitivity or specificity for diagnosing metaplastic gastritis between LCI and WLI. CONCLUSIONS: LCI has better diagnostic accuracy for H. pylori infection status than WLI. Clinical trial registration number: KCT0003674.

Production of ERCP training model using a 3D printing technique (with video).

BACKGROUND: ERCP training models are very different in terms of anatomical differences, ethical issues, storage problems, realistic tactile sensation, durability and portability. There is no easy way to select an optimized model for ERCP training. If the ERCP training model could be made as a soft silicone model using 3D printing technique, it would have numerous advantages over the models presented so far. The purpose of this study was to develop an optimized ERCP training model using a 3D printing technique and to try to find ways for implementing various practical techniques. METHODS: All organ parts of this model were fabricated using silicone molding techniques with 3D printing. Especially, various anatomy of the ampulla of Vater and common bile duct (CBD) were creatively designed for different diagnostic and therapeutic procedures. In order to manufacture each of the designed organ parts with silicone, a negative part had to be newly designed to produce the molder. The negative molders were 3D printed and then injection molding was applied to obtain organ parts in silicone material. The eight different types of ampulla and CBD were repeatedly utilized and replaced to the main system as a module-type. RESULTS: ERCP training silicone model using 3D technique was semi-permanently used to repeat various ERCP procedures. All ERCP procedures using this model could be observed by real-time fluoroscopic examination as well as endoscopic examination simultaneously. Using different ampulla and CBD modules, basic biliary cannulation, difficult cannulation, stone extraction, mechanical lithotripsy, metal stent insertion, plastic stent insertion, and balloon dilation were successfully and repeatedly achieved. Endoscopic sphincterotomy was also performed on a specialized ampulla using a Vienna sausage. After repeat procedures and trainings, all parts of organs including the ampulla and CBD modules were not markedly damaged or deformed. CONCLUSIONS: We made a specialized ERCP training silicon model with 3D printing technique. This model is durable, relatively cheap and easy to make, and thus allows the users to perform various specialized ERCP techniques, which increases its chances of being a good ERCP training model.

The diagnostic performance of novel torque technique for endoscopic ultrasound-guided tissue acquisition in solid pancreatic lesions: A prospective randomized controlled trial.

BACKGROUND AND AIM: Although several techniques for improved outcomes in endoscopic ultrasound (EUS)-guided tissue acquisition have been reported, the reported diagnostic yield for pancreatic masses is not satisfactory. The effects of novel technique (torque method) on twisting the scope in the clockwise or counterclockwise direction during EUS-fine needle biopsy (EUS-FNB) are unknown. We compared the diagnostic yield of EUS-FNB for pancreatic masses using the torque and standard techniques. METHODS: From April 20, 2017, to March 16, 2018, 124 consecutive patients with solid pancreatic mass who underwent EUS-FNB using either the torque or standard technique were randomly assigned. Three passes were made with each technique, comprising 10 uniform to-and-fro movements on each pass with a 10-mL syringe suction. The primary outcome was procurement rates of histologic cores, and the secondary outcomes were the diagnostic performance and technical failure. RESULTS: There were significant differences between the groups regarding the procurement rate of the histologic core and optimal quality core (standard vs torque: 87.1% [54/62] vs 98.4% [61/62], P = 0.038 and 79.0% [49/62] vs 93.5% [58/62], P = 0.037). The sensitivity, specificity, positive predictive value, and negative predictive values of EUS-FNB were 85.45%, 100%, 100%, and 46.67%, respectively, for the standard technique and 96.49%, 100%, 100%, and 71.43%, respectively, for the torque technique. The diagnostic accuracies of the standard and torque techniques were 87.10% and 96.77%, respectively. CONCLUSIONS: The torque technique for EUS-FNB offered acceptable technical feasibility and superior diagnostic performance, including optimal histologic core procurement, compared with the standard technique.

The AHR1-ARNT1 dimerization pair is a major regulator of the response to natural ligands, but not to TCDD, in the chicken.

The activation of the aryl hydrocarbon receptor (AHR) occurs through the binding of dioxin-like compounds (DLCs) or natural ligands. In this pathway, the AHR-ARNT (AHR nuclear translocator) heterodimer serves to regulate critical physiological functions, such as immune responses and the metabolism of xenobiotics. Birds have three AHR isoforms (AHR1, AHR1ß, and AHR2) and two ARNT isoforms (ARNT1 and ARNT2). However, how AHR and ARNT dimerization pair in birds regulates the AHR signaling pathway in an isoform-specific manner remains unknown. In this study, we initially sought to clarify the major chicken AHR-ARNT (ckAHR-ckARNT) pairs by estimating the mRNA tissue distributions of various ckAHR and ckARNT isoforms. Our results indicated that the ckAHR1-ckARNT1 represented the major dimerization pair in most tissues except the brain. We then measured the transactivation potencies of various ckAHR-ckARNT pairs by natural ligands and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), in in vitro reporter gene assays using COS-7 and LMH cell lines. Our results from the in vitro assays demonstrated that the ckAHR1-ckARNT1 pair was strongly activated by the five natural ligands, namely, 6-formylindolo [3,2-b]carbazole, L-kynurenin, kynurenic acid, indoxyl-3-sulfate, and 1,3,7-tribromodibenzo-p-dioxin, but not by TCDD. In in silico ligand docking simulations with ckAHR1 homology models, all the natural ligands showed a interaction pattern that was distinct from that observed with anthropogenic DLCs, including TCDD. In conclusion, our findings indicate that the ckAHR1-ckARNT1 may be the most important dimerization pair in most tissues for regulating the physiological functions driven by natural ligands, although it was less reactive to TCDD.

Necroptosis signaling in liver diseases: An update.

The apoptosis alternate cell death pathways are extensively studied in recent years and their significance has been well recognized. With identification of newer cell death pathways, the therapeutic opportunities to modulate cell death have indeed further extended. Necroptosis, among other apoptosis alternate pathways, has been immensely studied recently in different hepatic disease models. Receptor-interacting protein 1 (RIPK1), RIPK3 and mixed lineage kinase domain like (MLKL) seemed to be the key players to mediate necroptosis pathway. Initially, necroptosis seemed to be following the typical pathway. But recently diverse pathways and outcomes have been observed. With recent studies reporting diverse outcomes, the necroptosis signalling has become a lot more interesting and intricate. The typical RIPK1 signalling followed by RIPK3 and MLKL might not always be strictly followed. Although, necroptosis signalling has been intensively investigated in various disease conditions; however, there is still a need to further elaborate and understand the unique scaffolding and kinase properties and other signalling interactions of necroptosis signalling molecules.

Decrease in fat de novo synthesis and chemokine ligand expression in non-alcoholic fatty liver disease caused by inhibition of mixed lineage kinase domain-like pseudokinase.

BACKGROUND AND AIM: Receptor-interacting serine/threonine kinase 3 and mixed lineage kinase domain-like pseudokinase (MLKL) have gained attention as apoptosis alternate cell death signaling molecules. We aimed to evaluate the role of MLKL in non-alcoholic fatty liver disease (NAFLD). METHODS: Hepatic tissue MLKL expression was compared between NAFLD patients and healthy controls. High-fat diet was fed to wild-type and MLKL-knockout (KO) mice for 12 weeks. Brown adipose fat tissue was measured by [18 F]-fluorodeoxyglucose positron emission tomography. Energy expenditure was measured by indirect calorimetry. Anti-MLKL effects were also evaluated in in vitro setting using U937 and HepG2 cells. RESULTS: Hepatic tissue MLKL expression increased in NAFLD patients compared with healthy controls. MLKL expression increased according to the degree of steatosis, ballooning, and inflammation. High-fat diet-fed MLKL-KO mice displayed decreased alanine aminotransferase, triglycerides, liver weight, NAFLD activity score (6.3 vs 3.5, P < 0.001), steatosis score (3.0 vs 1.8, P < 0.001), inflammation, and ballooning degeneration compared with wild-type mice. SREBP1c, fatty acid synthase, and SCD-1 expressions decreased in MLKL-KO mice. Adipose tissue F4/80-positive crown-like structures were also reduced in MLKL-KO mice. HepG2 cells treated with necrosulfonamide (an MLKL inhibitor) showed reduced Nile red staining and reduced SREBP1c and SCD-1 expressions. Stimulation of necroptosis using lipopolysaccharide + caspase inhibitor (zVAD) increased CXCL1/2 expressions in U937 monocyte cells. Lipopolysaccharide + zVAD-induced increased expressions of CXCL1/2 were reduced with necrosulfonamide treatment. CONCLUSIONS: Mixed lineage kinase domain-like pseudokinase inhibition has protective effects in non-alcoholic steatohepatitis by decreasing hepatic de novo fat synthesis and chemokine (C-X-C motif) ligand expressions.

The aryl hydrocarbon receptor 2 potentially mediates cytochrome P450 1A induction in the jungle crow (Corvus macrorhynchos).

To understand the role of aryl hydrocarbon receptor (AHR) isoforms in avian species, we investigated the functional characteristics of two AHR isoforms (designated as jcAHR1 and jcAHR2) of the jungle crow (Corvus macrorhynchos). Two amino acid residues corresponding to Ile324 and Ser380 (high sensitive type) in chicken AHR1 that are known to determine dioxin sensitivity were Ile325 and Ala381 (moderate sensitive type) in jcAHR1 and Val306 and Ala362 (low sensitive type) in jcAHR2. The quantitative comparison of the two jcAHR mRNA expression levels in a Tokyo jungle crow population showed that jcAHR2 accounted for 92.4% in the liver, while jcAHR1 accounted for only 7.6%. Both in vitro-expressed jcAHR1 and jcAHR2 proteins exhibited a specific binding to [3H]-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Transactivation potencies for jcAHR1 and jcAHR2 in in vitro reporter gene assays were measured in jcAHR-expressed cells exposed to 16 dioxins and related compounds (DRCs). Both jcAHR1 and jcAHR2 were activated in a congener- and an isoform-specific manner. EC50 value of TCDD for jcAHR2 (0.61 nM) was six-fold higher than that for jcAHR1 (0.098 nM), but jcAHR2 had higher transactivation efficacy than jcAHR1 in terms of the magnitude of response. The high transactivation efficacy of jcAHR2 in DRCs is in contrast to that of AHR2s in other avian species with low transactivation efficacy. Molecular docking simulations of TCDD with in silico jcAHR1 and jcAHR2 homology models showed that the two sensitivity-decisive amino acids indirectly controlled TCDD-binding modes through their surrounding amino acids. Deletion assays of jcAHR2 revealed that 736-805 amino acid residues in the C-terminal region were critical for its transactivation. We suggest that jcAHR2 plays a critical role in regulating the AHR signaling pathway, at least in its highly expressed organs.

In vitro and in silico AHR assays for assessing the risk of heavy oil-derived polycyclic aromatic hydrocarbons in fish.

In the aftermath of the Great East Japan Earthquake of March 11, 2011, marine fish in Kesennuma Bay, Japan, have been contaminated with heavy oil containing polycyclic aromatic hydrocarbons (PAHs). To estimate the risk of six PAHs (benzo[α]pyrene, dibenzothiophene, phenanthrene, 2,3,5-trimethylnaphthalene, acenaphthene, and 1-methylphenanthrene), which have been detected at high levels in the tissues of fish from Kesennuma Bay, we attempted to evaluate the effects of these PAHs on the fish aryl hydrocarbon receptor (AHR) signaling pathway. We initially measured PAH concentrations and cytochrome P4501A catalytic activities (EROD: ethoxyresorufin-O-deethylase and MROD: methoxyresorufin-O-demethylase) as markers of AHR activation in greenlings (Hexagrammos otakii) collected from Kesennuma Bay in 2014. The results showed that alkylated PAH concentrations and EROD/MROD activities were higher in sites close to the oil-spilled sites than in the control site, suggesting AHR activation by spilled alkylated PAHs. We then investigated AHR-mediated responses to these PAHs in the in vitro reporter gene assay system where red seabream (Pagrus major) AHR1 (rsAHR1) or rsAHR2 expression plasmids were transiently transfected into COS-7 cells. The in vitro assay showed rsAHR isoform-, PAH-, and dose-dependent transactivation potencies. The relative effective concentrations of benzo[α]pyrene, dibenzothiophene, phenanthrene, 2,3,5-trimethylnaphthalene, acenaphthene, and 1-methylphenanthrene that induce 20% of the maximum benzo[α]pyrene response (REC20-BaP) for rsAHR1 activation were 0.052, 38, 79, 88, 270 nM, and no response, respectively, and those for rsAHR2 activation were 0.0049, 32, 53, 88, 60 nM, and no response, respectively. The results showed that the REC20-BaP values of benzo[α]pyrene for both the rsAHR1 and rsAHR2 isoforms were lower than the concentrations (0.041-0.20 nM) detected in the muscle tissue of fish from Kesennuma Bay, while the REC20-BaP values of other PAHs were higher than their tissue concentrations. In silico rsAHR homology modeling and subsequent ligand docking simulation analyses indicated that the rsAHR activation potencies of PAHs could be predicted from a rsAHR2 model. This study shows that in vitro and in silico rsAHR analyses may be a useful tool for assessing the risks to fish contaminated with PAHs.

Estimates of the Prevalence, Intensity and the Number of Workers Exposed to Cigarette Smoking across Occupations and Industries in Korea.

BACKGROUND: Tobacco smoking affects the incidence of various illnesses such as lung cancer, respiratory diseases, and cardiovascular diseases. In an effort to prevent smoking-related cancers, we aimed to estimate the smoking prevalence, intensity, and number of workers exposed to smoking, which would be specific to the occupational and industrial circumstances in Korea. METHODS: We used the Korean Working Condition Survey (KWCS) and Korea's Census data. Smoking prevalence and intensity were estimated using the KWCS data. The number of smokers was estimated by multiplying smoking prevalence with the number of workers in the occupation or industry. Smoking prevalence, intensity, and number of smokers were estimated for major, sub-major, and minor groups of occupation and industry. RESULTS: Of the total labor force in 2010, 52.66% of men and 5.24% of women workers were estimated to be current smokers. Men workers smoked 15.42 cigarettes/day, and women workers 11.29 cigarettes/day. In terms of occupation, "craft and related trades workers" demonstrated the highest smoking prevalence (52.24%). "Managers" smoked the highest number of cigarettes (16.63 cigarettes/day) and "equipment, machine operating, and assembling workers" comprised the largest number of estimated smokers (1,368,726 workers). In terms of industry, "mining and quarrying" had the highest smoking prevalence (69.27%). Those in "construction" smoked the highest number of cigarettes (17.16 cigarettes/day) and those in "manufacturing" comprised the largest number of estimated smokers (1,629,893 workers). CONCLUSION: Our results may help in setting priorities for smoking prevention-related activities. In addition, these results can be used for epidemiological studies controlling for the effect of smoking by occupation or industry.