Integrator complex subunit 15 controls mRNA splicing and is critical for eye development.

The eye and brain are composed of elaborately organized tissues, development of which is supported by spatiotemporally precise expression of a number of transcription factors and developmental regulators. Here we report the molecular and genetic characterization of Integrator complex subunit 15 (INTS15). INTS15 was identified in search for the causative gene(s) for an autosomal-dominant eye disease with variable individual manifestation found in a large pedigree. While homozygous Ints15 knockout mice are embryonic lethal, mutant mice lacking a small C-terminal region of Ints15 show ocular malformations similar to the human patients. INTS15 is highly expressed in the eye and brain during embryogenesis and stably interacts with the Integrator complex to support small nuclear RNA 3' end processing. Its knockdown resulted in missplicing of a large number of genes, probably as a secondary consequence, and substantially affected genes associated with eye and brain development. Moreover, studies using human iPS cells-derived neural progenitor cells showed that INTS15 is critical for axonal outgrowth in retinal ganglion cells. This study suggests a new link between general transcription machinery and a highly specific hereditary disease.

Poor Diagnostic Efficacy of Noninvasive Tests for Advanced Fibrosis in Obese or Younger Than 60 Diabetic NAFLD patients.

BACKGROUND & AIMS: Serum-based noninvasive tests (NITs) have been widely used to assess liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). However, the diagnostic efficacy of NITs across ranges of age, body mass index (BMI), and presence of type 2 diabetes (T2DM) may vary and have not been well-characterized. METHODS: We analyzed 1489 patients with biopsy-proven NAFLD from 6 centers in Japan, Taiwan, and Korea. Using histology as the gold standard, we compared the areas under the receiver operating characteristic (AUROCs) of Fibrosis-4 index (FIB-4), NAFLD fibrosis score (NFS), and the new Hepamet fibrosis score (HFS), with a focus on performance in subgroups as stratified by age, BMI, and the presence of T2DM. RESULTS: By histology, 44.0% of the overall cohort (655/1489) had F2-4, and 20.6% (307/1489) had F3-4 fibrosis. FIB-4 had the highest AUROCs for both F2-4 (0.701 vs NFS 0.676 and HFS 0.682, P = .001) and F3-4 (0.767 vs NFS 0.736 and HFS 0.752, P = .002). However, for F3-4 fibrosis, the AUROCs of all 3 NITs were generally higher in older (>60 years), nonobese (BMI <25 kg/m2), and non-diabetic patients, although overall the best performance was observed with FIB-4 among nonobese (BMI<25) diabetic patients (AUROC, 0.92). The worst performance was observed in younger patients with T2DM for all NITs including FIB-4 (AUROC, 0.63-0.66). CONCLUSIONS: FIB-4 had higher diagnostic efficacy for F3-4 than NFS or HFS, but this varied greatly by age, BMI, and T2DM, with better performance in older, nonobese, and nondiabetic patients. However, all NITs including FIB-4 had unacceptably poor performance in young or obese diabetic patients.

Decamethylcyclopentasiloxane affects estradiol production in female rats but not H295R cells.

Sex hormones, such as androgens and estrogens, are predominantly produced in the gonads (ovaries and testes) and adrenal cortex. Endocrine-disrupting chemicals (EDCs) are substances that mimic, block, or interfere with hormones in the endocrine systems of humans and organisms. EDCs mainly act via nuclear receptors and steroidogenesis-related enzymes. In the OECD conceptual framework for testing and assessment of EDCs, several well-known assays are used to identify the potential disruption of nuclear receptors both in vivo and in vitro, whereas the H295R steroidogenesis assay is the only assay that detects the disruption of steroidogenesis. Forskolin and prochloraz are often used as positive controls in the H295R steroidogenesis assay. Decamethylcyclopentasiloxane (D5) was suspected one of EDCs, but the effects of D5 on steroidogenesis remain unclear. To establish a short-term in vivo screening method that detects the disruption of steroidogenesis, rats in the present study were fed a diet containing forskolin, prochloraz, or D5 for 14 days. Forskolin increased plasma levels of 17ß-estradiol (E2) and testosterone as well as the mRNA level of Cyp19 in both the adrenal glands and ovaries. Prochloraz induced the loss of cyclicity in the sexual cycle and decreased plasma levels of E2 and testosterone. D5 increased E2 levels and shortened the estrous cycle in a dose-dependent manner; however, potential endocrine disruption was not detected in the H295R steroidogenesis assay. These results demonstrate the importance of comprehensively assessing the endocrine-disrupting effects of chemicals on steroidogenesis in vivo.

Determining the factors affecting serum presepsin level and its diagnostic utility: A cross-sectional study.

INTRODUCTION: This study aimed to identify factors affecting presepsin levels and to determine their diagnostic utility. METHODS: This cross-sectional study was conducted at an outpatient clinic and emergency department at an acute care hospital in Japan between January 2015 and December 2017. We enrolled 1,840 consecutive outpatients with at least one measurement of serum presepsin, who were suspected of having bacterial infection. The outcome variables were bacterial infection, lower respiratory tract infection, urinary tract infection, cholangitis, and other infections diagnoses, based on the chart review. We collected blood analysis data on the patients' presepsin levels. RESULTS: There was a significant association between presepsin level and the diagnosis of bacterial infection even when adjusted for age, sex, renal function, and biliary enzyme levels. An increase of 1 unit in the log of presepsin values resulted in a relative risk ratio of 1.71 (1.09-2.66), 2.1 (1.58-2.79), 2.93 (2.05-4.19), 4.7(2.90-7.61), and 2.41(1.70-3.43), for bacterial infection, lower respiratory tract infection, urinary tract infection, cholangitis, and other infections, respectively. CONCLUSIONS: Presepsin showed a statistically significant increase in the diagnosis of bacterial infections (lower respiratory tract infections, urinary tract infections, cholangitis, and non-severe patients) in a community hospital setting. However, in patients with renal dysfunction, presepsin levels should be interpreted with caution.

The protective effect of tight-fitting powered air-purifying respirators during chest compressions.

BACKGROUND: Airborne personal protective equipment is required for healthcare workers when performing aerosol-generating procedures on patients with infectious diseases. Chest compressions, one of the main components of cardiopulmonary resuscitation, require intense and dynamic movements of the upper body. We aimed to investigate the protective effect of tight-fitting powered air-purifying respirators (PAPRs) during chest compressions. METHODS: This single-center simulation study was performed from February 2021 to March 2021. The simulated workplace protection factor (SWPF) is the concentration ratio of ambient particles and particles inside the PAPR mask; this value indicates the level of protection provided by a respirator when subjected to a simulated work environment. Participants performed continuous chest compressions three times for 2 min each time, with a 4-min break between each session. We measured the SWPF of the tight-fitting PAPR during chest compression in real-time mode. The primary outcome was the ratio of any failure of protection (SWPF <500) during the chest compression sessions. RESULTS: Fifty-four participants completed the simulation. Overall, 78% (n = 42) of the participants failed (the measured SWPF value was less than 500) at least one of the three sessions of chest compressions. The median value and interquartile range of the SWPF was 4304 (685-16,191). There were no reports of slipping down of the respirator or mechanical failure during chest compressions. CONCLUSIONS: Although the median SWPF value was high during chest compressions, the tight-fitting PAPR did not provide adequate protection.

G-quadruplex DNA and RNA: Their roles in regulation of DNA replication and other biological functions.

G-quadruplex is one of the best-studied non-B type DNA that is now known to be prevalently present in the genomes of almost all the biological species. Recent studies reveal roles of G-quadruplex (G4) structures in various nucleic acids and chromosome transactions. In this short article, we will first describe recent findings on the roles of G4 in regulation of DNA replication. G4 is involved in regulation of spatio-temporal regulation of DNA replication through interaction with a specific binding protein, Rif1. This regulation is at least partially mediated by generation of specific chromatin architecture through Rif1-G4 interactions. We will also describe recent studies showing the potential roles of G4 in initiation of DNA replication. Next, we will present showcases of highly diversified roles of DNA G4 and RNA G4 in regulation of nucleic acid and chromosome functions. Finally, we will discuss how the formation of cellular G4 could be regulated.

Efficacy and Safety of Sorafenib in Unresectable Hepatocellular Carcinoma with Bile Duct Invasion.

INTRODUCTION: Because the frequency of bile duct invasion in hepatocellular carcinoma (HCC) patients is very rare, there is limited clinical evidence to demonstrate the outcomes of systemic therapy in HCC with bile duct invasion. OBJECTIVE: Our aim was to clarify the efficacy and safety of sorafenib treatment in patients with unresectable advanced HCC with bile duct invasion. METHODS: One hundred and seventy-five patients with advanced HCC were enrolled in this study. We retrospectively compared the outcomes of sorafenib between patients without bile duct invasion [B (-) group, n = 165] and those with bile duct invasion [B (+) group, n = 10]. RESULTS: There were no significant differences in the confirmed objective response rate (ORR) and the confirmed disease control (DC) rate between the B (-) and the B (+) groups (13.9 vs. 20.0%, p = 0.637 for ORR; 47.2 vs. 70.0%, p = 0.202 for DC rate, respectively). There were no significant differences in median overall survival (OS) and time to progression (TTP) between the B (-) group and the B (+) group (14.8 vs. 14.1 months, p = 0.780 for OS; 3.4 vs. 5.7 months, p = 0.277 for TTP, respectively). Post-treatment factors associated with good OS were changes in albumin-bilirubin score (0-6 weeks) of <0.25, and antitumor response at 6 weeks of DC. Though 5 of 10 patients (50%) in the B (+) group had bile duct complications, such as obstructive jaundice and biliary bleeding, these 5 patients were able to recover from biliary troubles by careful and vigorous management with biliary endoscopic intervention, and were able to continue sorafenib therapy safely. CONCLUSIONS: Our present results suggest that sorafenib might have potential therapeutic efficacy and safety in advanced HCC patients with bile duct invasion. In case of biliary tract troubles before and during sorafenib treatment, early biliary management may be important to continue sorafenib therapy safely. Further studies are needed to confirm the outcomes of sorafenib in advanced HCC patients with bile duct invasion.

Fork restart protein, PriA, binds around oriC after depletion of nucleotide precursors: Replication fork arrest near the replication origin.

Arrest of replication fork progression is one of the most common causes for increasing the genomic instability. In bacteria, PriA, a conserved DEXH-type helicase, plays a major role in recognition of the stalled forks and restart of DNA replication. We took advantage of PriA's ability to specifically recognize stalled replication forks to determine the genomic loci where replication forks are prone to stall on the Escherichia coli genome. We found that PriA binds around oriC upon thymine starvation which reduces the nucleotide supply and causes replication fork stalling. PriA binding quickly disappeared upon readdition of thymine. Furthermore, BrdU was incorporated at around oriC upon release from thymine starvation. Our results indicate that reduced supply of DNA replication precursors causes replication fork stalling preferentially in the 600 kb segment centered at oriC. This suggests that replication of the vicinity of oriC requires higher level of nucleotide precursors. The results also point to a possibility of slow fork movement and/or the presence of multiple fork arrest signals within this segment. Indeed, we have identified rather strong fork stall/pausing signals symmetrically located at ∼50 kb away from oriC. We speculate that replication pausing and fork-slow-down shortly after initiation may represent a novel checkpoint that ensures the presence of sufficient nucleotide supply prior to commitment to duplication of the entire genome.

Identification and characterization of natural microbial products that alter the free d-aspartate content of mammalian cells.

Mammalian cells possess the molecular apparatus necessary to take up, degrade, synthesize, and release free d-aspartate, which plays an important role in physiological functions within the body. Here, biologically active microbial compounds and pre-existing drugs were screened for their ability to alter the intracellular d-aspartate level in mammalian cells, and several candidate compounds were identified. Detailed analytical studies suggested that two of these compounds, mithramycin A and geldanamycin, suppress the biosynthesis of d-aspartate in cells. Further studies suggested that these compounds act at distinct sites within the cell. These compounds may advance our current understanding of biosynthesis of d-aspartate in mammals, a whole picture of which remains to be disclosed.

The Runt domain of AML1 (RUNX1) binds a sequence-conserved RNA motif that mimics a DNA element.

AML1 (RUNX1) is a key transcription factor for hematopoiesis that binds to the Runt-binding double-stranded DNA element (RDE) of target genes through its N-terminal Runt domain. Aberrations in the AML1 gene are frequently found in human leukemia. To better understand AML1 and its potential utility for diagnosis and therapy, we obtained RNA aptamers that bind specifically to the AML1 Runt domain. Enzymatic probing and NMR analyses revealed that Apt1-S, which is a truncated variant of one of the aptamers, has a CACG tetraloop and two stem regions separated by an internal loop. All the isolated aptamers were found to contain the conserved sequence motif 5'-NNCCAC-3' and 5'-GCGMGN'N'-3' (M:A or C; N and N' form Watson-Crick base pairs). The motif contains one AC mismatch and one base bulged out. Mutational analysis of Apt1-S showed that three guanines of the motif are important for Runt binding as are the three guanines of RDE, which are directly recognized by three arginine residues of the Runt domain. Mutational analyses of the Runt domain revealed that the amino acid residues used for Apt1-S binding were similar to those used for RDE binding. Furthermore, the aptamer competed with RDE for binding to the Runt domain in vitro. These results demonstrated that the Runt domain of the AML1 protein binds to the motif of the aptamer that mimics DNA. Our findings should provide new insights into RNA function and utility in both basic and applied sciences.

A Case Study of Non-specialist Disease Management Using Teladoc Health Support: A Case Report.

In Japan, there is a shortage of emergency medicine specialists, often leading non-specialists (physicians who treat conditions outside their area of specialty) to handle cases outside their expertise, which can cause challenges and necessitate specialist support. Starting from December 2023, the St. Marianna University Hospital, which has emergency medicine specialists, began offering overnight emergency outpatient support to Kawasaki Municipal Tama Hospital using the Teladoc HEALTH Mini Cart telemedicine device (Teladoc Health, Inc., CA, USA). The case involved a 44-year-old male with a history of peritonsillar abscess and incisional drainage presented with pharyngeal pain. The treating physician at the Kawasaki Municipal Tama Hospital and a neurologist (the supported physician) examined the patient at 9 PM. An enlarged right tonsil was noted, and a peritonsillar abscess was suspected, prompting a contrast-enhanced CT scan. The results confirmed a 1 cm right peritonsillar abscess. Faced with the decision to transfer the patient to a higher medical facility, the supported physician consulted with the support physician through a Teladoc HEALTH Mini Cart. The St. Marianna University Hospital's emergency physician (supporting physician) used the Teladoc HEALTH Mini Cart to assess the patient's overall condition, blood tests, and CT images and advise on antibiotic treatment. A visit to the ear, nose, and throat expert (ENT) the following day was considered sufficient. The supported physician received feedback that the use of the Teladoc HEALTH Mini Cart reduced the burden of nighttime transfers for otolaryngological conditions, which can take several hours. This finding suggests that remote medical support can affect Japan's emergency medical system.

Modeling long-term transfers of radiocesium in farmland under different tillage and cover crop treatments.

The 2011 nuclear accident at Japan's Fukushima Daiichi Nuclear Power Plant (FDNPP) prompted inquiries about the long-term transfer of Cesium-137 (137Cs) from soil to agricultural plants. In this context, numerical modeling is particularly useful for the long-term evaluation of the consequences of agroecosystem contamination. Agricultural practices, such as tillage and cover cropping, play key roles in 137Cs recycling in agroecosystems. In this study, we used 10-year monitoring data to develop a dynamic model to predict 137Cs redistribution (via uptake, litterfall, translocation, and percolation) under different tillage (no-tillage, NT; rotary cultivation, RC; moldboard plow, MP) and cover crop (rye; hairy vetch; fallow weed) treatments. The verification exercise and assessment results indicated the model's reliability, as the temporal dynamics of predicted values agreed with observed values. Tillage significantly influenced the 137Cs distribution in soil, thereby decreasing plant uptake of 137Cs, whereas cover crop exerted a minimal effect on 137Cs cycling. Furthermore, while the 137Cs concentrations in soybean grain under RC and NT treatments were comparable 62 years after the FDNPP accident, the concentration under MP treatment remained consistently the lowest. Despite natural decay being the main cause of the decreased global 137Cs level in the agroecosystem, with minimal losses from percolation to deeper soil layers and soybean harvesting, adopting an appropriate tillage practice was shown to promote a long-term reduction of 137Cs concentration in crops. Finally, to improve the model's accuracy, further research should consider incorporating the effects of soil properties and extreme weather events on 137Cs flow into the model, as these factors are essential for realizing improved agroecosystem predictions.

A chatbot to improve adherence to internet-based cognitive-behavioural therapy among workers with subthreshold depression: a randomised controlled trial.

BACKGROUND: Internet-based cognitive-behavioural therapy (iCBT) is effective for subthreshold depression. However, iCBT has problems with adherence, especially when unaccompanied by human guidance. Knowledge on how to enhance adherence to iCBT without human involvement can contribute to improving the effectiveness of iCBT. OBJECTIVE: This is an implementation study to examine the effect of an automated chatbot to improve the adherence rate of iCBT. METHODS: We developed a chatbot to increase adherence to an existing iCBT programme, and a randomised controlled trial was conducted with two groups: one group using iCBT plus chatbot (iCBT+chatbot group) and one group not using the chatbot (iCBT group). Participants were full-time employees with subthreshold depression working in Japan (n=149, age mean=41.4 (SD=11.1)). The primary endpoint was the completion rate of the iCBT programme at 8 weeks. FINDINGS: We analysed data from 142 participants for the primary outcome. The completion rate of the iCBT+chatbot group was 34.8% (24/69, 95% CI 23.5 to 46.0), that of the iCBT group was 19.2% (14/73, 95% CI 10.2 to 28.2), and the risk ratio was 1.81 (95% CI 1.02 to 3.21). CONCLUSIONS: Combining iCBT with a chatbot increased participants' iCBT completion rate. CLINICAL IMPLICATIONS: Encouraging messages from the chatbot could improve participation in an iCBT programme. Further studies are needed to investigate whether chatbots can improve adherence to the programme in the long term and to assess their impact on depression, anxiety and well-being. TRIAL REGISTRATION NUMBER: UMIN000047621.

Modeling of Retina and Optic Nerve Ischemia-Reperfusion Injury through Hypoxia-Reoxygenation in Human Induced Pluripotent Stem Cell-Derived Retinal Ganglion Cells.

Retinal ganglion cells (RGCs) are specialized projection neurons that constitute part of the retina, and the death of RGCs causes various eye diseases, but the mechanism of RGC death is still unclear. Here, we induced cell death in human induced pluripotent stem cell (hiPSC)-derived RGC-rich retinal tissues using hypoxia-reoxygenation in vitro. Flow cytometry, immunochemistry, and Western blotting showed the apoptosis and necrosis of RGCs under hypoxia-reoxygenation, and they were rescued by an apoptosis inhibitor but not by a necrosis inhibitor. This revealed that the cell death induced in our model was mainly due to apoptosis. To our knowledge, this is the first model to reproduce ischemia-reperfusion in hiPSC-derived RGCs. Thus, the efficacy of apoptosis inhibitors and neuroprotective agents can be evaluated using this model, bringing us closer to clinical applications.

External validation of the HACOR score and ROX index for predicting treatment failure in patients with coronavirus disease 2019 pneumonia managed on high-flow nasal cannula therapy: a multicenter retrospective observational study in Japan.

BACKGROUND: The HACOR score for predicting treatment failure includes vital signs and acid-base balance factors, whereas the ROX index only considers the respiratory rate, oxygen saturation, and fraction of inspired oxygen (FiO2). We aimed to externally validate the HACOR score and ROX index for predicting treatment failure in patients with coronavirus disease 2019 (COVID-19) on high-flow nasal cannula (HFNC) therapy in Japan. METHODS: This retrospective, observational, multicenter study included patients, aged ≥ 18 years, diagnosed with COVID-19 and treated with HFNC therapy between January 16, 2020, and March 31, 2022. The HACOR score and ROX index were calculated at 2, 6, 12, 24, and 48 h after stating HFNC therapy. The primary outcome was treatment failure (requirement for intubation or occurrence of death within 7 days). We calculated the area under the receiver operating characteristic curve (AUROC) and assessed the diagnostic performance of these indicators. The 2-h time-point prediction was considered the primary analysis and that of other time-points as the secondary analysis. We also assessed 2-h time-point sensitivity and specificity using previously reported cutoff values (HACOR score > 5, ROX index < 2.85). RESULTS: We analyzed 300 patients from 9 institutions (median age, 60 years; median SpO2/FiO2 ratio at the start of HFNC therapy, 121). Within 7 days of HFNC therapy, treatment failure occurred in 127 (42%) patients. The HACOR score and ROX index at the 2-h time-point exhibited AUROC discrimination values of 0.63 and 0.57 (P = 0.24), respectively. These values varied with temporal changes-0.58 and 0.62 at 6 h, 0.70 and 0.68 at 12 h, 0.68 and 0.69 at 24 h, and 0.75 and 0.75 at 48 h, respectively. The 2-h time-point sensitivity and specificity were 18% and 91% for the HACOR score, respectively, and 3% and 100% for the ROX index, respectively. Visual calibration assessment revealed well calibrated HACOR score, but not ROX index. CONCLUSIONS: In COVID-19 patients receiving HFNC therapy in Japan, the predictive performance of the HACOR score and ROX index at the 2-h time-point may be inadequate. Furthermore, clinicians should be mindful of time-point scores owing to the variation of the models' predictive performance with the time-point. Trial registration UMIN (registration number: UMIN000050024, January 13, 2023).

Association between loss of hypercoagulable phenotype, clinical features and complement pathway consumption in COVID-19.

Background: Coronavirus disease 2019 (COVID-19) features a hypercoagulable state, but therapeutic anticoagulation effectiveness varies with disease severity. We aimed to evaluate the dynamics of the coagulation profile and its association with COVID-19 severity, outcomes, and biomarker trajectories. Methods: This multicenter, prospective, observational study included patients with COVID-19 requiring respiratory support. Rotational thromboelastometry findings were evaluated for coagulation and fibrinolysis status. Hypercoagulable status was defined as supranormal range of maximum clot elasticity in an external pathway. Longitudinal laboratory parameters were collected to characterize the coagulation phenotype. Results: Of 166 patients, 90 (54%) were severely ill at inclusion (invasive mechanical ventilation, 84; extracorporeal membrane oxygenation, 6). Higher maximum elasticity (P=0.02) and lower maximum lysis in the external pathway (P=0.03) were observed in severely ill patients compared with the corresponding values in patients on non-invasive oxygen supplementation. Hypercoagulability components correlated with platelet and fibrinogen levels. Hypercoagulable phenotype was associated with favorable outcomes in severely ill patients, while normocoagulable phenotype was not (median time to recovery, 15 days vs. 27 days, P=0.002), but no significant association was observed in moderately ill patients. In patients with severe COVID-19, lower initial C3, minimum C3, CH50, and greater changes in CH50 were associated with the normocoagulable phenotype. Changes in complement components correlated with dynamics of coagulation markers, hematocrit, and alveolar injury markers. Conclusions: While hypercoagulable states become more evident with increasing severity of respiratory disease in patients with COVID-19, normocoagulable phenotype is associated with triggered by alternative pathway activation and poor outcomes.

How dynamic transfer models can complement an equilibrium-based approach: Case studies of radiocesium transfer to forest trees following accidental atmospheric release.

Accidental release of radionuclides caused by nuclear accidents like those in Fukushima and Chernobyl can result in pulses of radioactivity entering the forest environment. Due to intense recycling in the forest, equilibrium between radioactivity concentrations in trees and in soil may not be reached during the period of short-term radionuclide transport following the accident. Another question arises as to whether the equilibrium hypothesis using empirical concentration ratios (CRs) can be applied to the long-term period. Using two atmospheric 137Cs fallout scenarios in the Fukushima and Chernobyl sites, this study investigated whether the CR approach could provide conservative predictions of 137Cs levels in trees following 137Cs fallout events by comparing predictions from the CR approach using data gathered for trees by the IAEA to those from dynamic transfer models and actual measured data. The inter-comparisons also aimed to investigate whether the CR approach could account for the variability of 137Cs levels across different tree organs. The results showed that caution may be necessary when using the CR approach, which relies on the IAEA dataset, to estimate 137Cs accumulation in forest trees in the short - and long term following atmospheric 137Cs fallout events. A calculation by TRIPS 2.0 demonstrated the importance of considering the distribution within tree organs for in-depth analysis of radiological impact of forest trees. Our findings suggest that it may be preferable to use CR values based on site-specific data rather than generic data collected from various sites. This is particularly relevant when studying the sites where the bioavailability of 137Cs for trees and thus possible exposures are higher. This study also showed that dynamic modeling approaches could offer an alternative means of estimating CR values of the entire tree or specific tree organs in situations where empirically derived values are not available.

Proteomic Analysis Reveals Changes in Tight Junctions in the Small Intestinal Epithelium of Mice Fed a High-Fat Diet.

The impact of a high-fat diet (HFD) on intestinal permeability has been well established. When bacteria and their metabolites from the intestinal tract flow into the portal vein, inflammation in the liver is triggered. However, the exact mechanism behind the development of a leaky gut caused by an HFD is unclear. In this study, we investigated the mechanism underlying the leaky gut related to an HFD. C57BL/6J mice were fed an HFD or control diet for 24 weeks, and their small intestine epithelial cells (IECs) were analyzed using deep quantitative proteomics. A significant increase in fat accumulation in the liver and a trend toward increased intestinal permeability were observed in the HFD group compared to the control group. Proteomics analysis of the upper small intestine epithelial cells identified 3684 proteins, of which 1032 were differentially expressed proteins (DEPs). Functional analysis of DEPs showed significant enrichment of proteins related to endocytosis, protein transport, and tight junctions (TJ). Expression of Cldn7 was inversely correlated with intestinal barrier function and strongly correlated with that of Epcam. This study will make important foundational contributions by providing a comprehensive depiction of protein expression in IECs affected by HFD, including an indication that the Epcam/Cldn7 complex plays a role in leaky gut.

Distinct features of two lipid droplets types in cell nuclei from patients with liver diseases.

Lipid droplets (LDs) have been observed in the nuclei of hepatocytes; however, their significance in liver disease remains unresolved. Our purpose was to explore the pathophysiological features of intranuclear LDs in liver diseases. We included 80 patients who underwent liver biopsies; the specimens were dissected and fixed for electron microscopy analysis. Depending on the presence of adjacent cytoplasmic invagination of the nuclear membrane, LDs in the nuclei were classified into two types: nucleoplasmic LDs (nLDs) and cytoplasmic LD invagination with nucleoplasmic reticulum (cLDs in NR). nLDs were found in 69% liver samples and cLDs in NR were found in 32%; no correlation was observed between the frequencies of the two LD types. nLDs were frequently found in hepatocytes of patients with nonalcoholic steatohepatitis, whereas cLDs in NR were absent from the livers of such patients. Further, cLDs in NR were often found in hepatocytes of patients with lower plasma cholesterol level. This indicates that nLDs do not directly reflect cytoplasmic lipid accumulation and that formation of cLDs in NR is inversely correlated to the secretion of very low-density lipoproteins. Positive correlations were found between the frequencies of nLDs and endoplasmic reticulum (ER) luminal expansion, suggesting that nLDs are formed in the nucleus upon ER stress. This study unveiled the presence of two distinct nuclear LDs in various liver diseases.

Stalled replication forks: making ends meet for recognition and stabilization.

In bacteria, PriA protein, a conserved DEXH-type DNA helicase, plays a central role in replication restart at stalled replication forks. Its unique DNA-binding property allows it to recognize and stabilize stalled forks and the structures derived from them. Cells must cope with fork stalls caused by various replication stresses to complete replication of the entire genome. Failure of the stalled fork stabilization process and eventual restart could lead to various forms of genomic instability. The low viability of priA null cells indicates a frequent occurrence of fork stall during normal growth that needs to be properly processed. PriA specifically recognizes the 3'-terminus of the nascent leading strand or the invading strand in a displacement (D)-loop by the three-prime terminus binding pocket (TT-pocket) present in its unique DNA binding domain. Elucidation of the structural basis for recognition of arrested forks by PriA should provide useful insight into how stalled forks are recognized in eukaryotes.