Background and Aims
Mitochondrial double‐stranded RNA (mtdsRNA) and its innate immune responses have been reported previously; however, mtdsRNA generation and its effects on alcohol‐associated liver ...disease (ALD) remain unclear. Here, we report that hepatic mtdsRNA stimulates toll‐like receptor 3 (TLR3) in Kupffer cells through the exosome (Exo) to enhance interleukin (IL)‐17A (IL‐17A) production in ALD.
Approach and Results
Following binge ethanol (EtOH) drinking, IL‐17A production primarily increased in γδ T cells of wild‐type (WT) mice, whereas the production of IL‐17A was mainly facilitated by CD4+ T cells in acute‐on‐chronic EtOH consumption. These were not observed in TLR3 knockout (KO) or Kupffer cell–depleted WT mice. The expression of polynucleotide phosphorylase, an mtdsRNA‐restricting enzyme, was significantly decreased in EtOH‐exposed livers and hepatocytes of WT mice. Immunostaining revealed that mtdsRNA colocalized with the mitochondria in EtOH‐treated hepatocytes from WT mice and healthy humans. Bioanalyzer analysis revealed that small‐sized RNAs were enriched in EtOH‐treated Exos (EtOH‐Exos) rather than EtOH‐treated microvesicles in hepatocytes of WT mice and humans. Quantitative real‐time PCR and RNA sequencing analyses indicated that mRNA expression of mitochondrial genes encoded by heavy and light strands was robustly increased in EtOH‐Exos from mice and humans. After direct treatment with EtOH‐Exos, IL‐1β expression was significantly increased in WT Kupffer cells but not in TLR3 KO Kupffer cells, augmenting IL‐17A production of γδ T cells in mice and humans.
Conclusions
EtOH‐mediated generation of mtdsRNA contributes to TLR3 activation in Kupffer cells through exosomal delivery. Consequently, increased IL‐1β expression in Kupffer cells triggers IL‐17A production in γδ T cells at the early stage that may accelerate IL‐17A expression in CD4+ T cells in the later stage of ALD. Therefore, mtdsRNA and TLR3 may function as therapeutic targets in ALD.
Non-alcoholic fatty liver disease (NAFLD) is a dominant cause of chronic liver disease, but the exact mechanism of progression from simple steatosis to nonalcoholic steatohepatitis (NASH) remains ...unknown. Here, we investigated the role of exosomes in NAFLD progression. Exosomes were isolated from a human hepatoma cell line treated with palmitic acid (PA) and their miRNA profiles examined by microarray. The human hepatic stellate cell (HSC) line (LX-2) was then treated with exosome isolated from hepatocytes. Compared with controls, PA-treated hepatocytes displayed significantly increased CD36 and exosome production. The microarray analysis showed there to be distinctive miRNA expression patterns between exosomes from vehicle- and PA-treated hepatocytes. When LX-2 cells were cultured with exosomes from PA-treated hepatocytes, the expression of genes related to the development of fibrosis were significantly amplified compared to those treated with exosomes from vehicle-treated hepatocytes. In conclusion, PA treatment enhanced the production of exosomes in these hepatocytes and changed their exosomal miRNA profile. Moreover, exosomes derived from PA-treated hepatocytes caused an increase in the expression levels of fibrotic genes in HSCs. Therefore, exosomes may have important roles in the crosstalk between hepatocytes and HSCs in the progression from simple steatosis to NASH.
AMP-activated protein kinase (AMPK) plays a key role in controlling energy metabolism in response to physiological and nutritional status. Although AMPK activation has been proposed as a promising ...molecular target for treating obesity and its related comorbidities, the use of pharmacological AMPK activators has been met with contradictory therapeutic challenges. Here we show a regulatory mechanism for AMPK through its ubiquitination and degradation by the E3 ubiquitin ligase makorin ring finger protein 1 (MKRN1). MKRN1 depletion promotes glucose consumption and suppresses lipid accumulation due to AMPK stabilisation and activation. Accordingly, MKRN1-null mice show chronic AMPK activation in both liver and adipose tissue, resulting in significant suppression of diet-induced metabolic syndrome. We demonstrate also its therapeutic effect by administering shRNA targeting MKRN1 into obese mice that reverses non-alcoholic fatty liver disease. We suggest that ubiquitin-dependent AMPK degradation represents a target therapeutic strategy for metabolic disorders.
We investigated the role of connexin 43 (Cx43) in maintaining the integrity of mitochondria in brown adipose tissue (BAT). The functional effects of Cx43 were evaluated using inducible, ...adipocyte-specific Cx43 knockout in mice (Gja1
KO) and by overexpression and knockdown of Cx43 in cultured adipocytes. Mitochondrial morphology was evaluated by electron microscopy and mitochondrial function and autophagy were assessed by immunoblotting, immunohistochemistry, and qPCR. The metabolic effects of adipocyte-specific knockout of Cx43 were assessed during cold stress and following high fat diet feeding. Cx43 expression was higher in BAT compared to white adipose tissue. Treatment with the β3-adrenergic receptor agonist CL316,243 increased Cx43 expression and mitochondrial localization. Gja1
KO mice reduced mitochondrial density and increased the presence of damaged mitochondria in BAT. Moreover, metabolic activation with CL316,243 further reduced mitochondrial integrity and upregulated autophagy in the BAT of Gja1
KO mice. Inhibition of Cx43 in cultured adipocytes increased the generation of reactive oxygen species and induction of autophagy during β-adrenergic stimulation. Gja1
KO mice were cold intolerant, expended less energy in response to β3-adrenergic receptor activation, and were more insulin resistant after a high-fat diet challenge. Collectively, our data demonstrate that Cx43 is required for maintaining the mitochondrial integrity and metabolic activity of BAT.
Summary
In a prospective, explorative study, the donor‐source difference of haploidentical family (HF), matched sibling (MS), and unrelated donors (UD) was evaluated for the outcome of haematopoietic ...cell transplantations (HCT) in 101 patients with acute myeloid leukaemia (AML) in complete remission (CR). To eliminate compounding effects, a uniform conditioning regimen containing antithymocyte globulin (ATG) was used. After transplantation, there was a significantly higher cumulative incidence of acute graft‐versus‐host disease (GVHD) in HF‐HCT patients (49%, 7%, and 16% for HF‐, MS‐ and UD‐HCT respectively; p < 0.001). A quarter of acute GVHD cases observed in HF‐HCT patients occurred within three days of engraftment and were characterized by diffuse skin rash, fever, weight gain, and hypoalbuminaemia. This peri‐engraftment acute GVHD was not observed in MS‐HCT or UD‐HCT patients. Additionally, a significantly higher proportion of HF‐HCT patients achieved complete donor chimaerism in the peripheral mononuclear cells at one month (88%, 46%, and 69% for HF‐, MS‐ and UD‐HCT respectively; p = 0.001). There was no significant difference in engraftment, chronic GVHD, leukaemia recurrence, non‐relapse mortality, and patient survival. In patients with AML in CR who received HCT using ATG‐containing conditioning, stronger donor–patient alloreactivity was observed in HF‐HCT, in terms of increased acute GVHD and higher likelihood of complete donor chimaerism.
We proposed wideband antireflective circular polarizer for realizing a true black state in all viewing directions in organic light-emitting-diode displays (OLEDs). Present commercialized wideband ...circular polarizer consisted of a half wave and a quarter wave plates having the refractive index parameter (Nz) of 1.5 in both films exhibits light leakage in the oblique viewing directions, deteriorating image quality of a black state. We evaluated Nzs of both films and proposed a new wideband antireflective circular polarizer with a perfect dark state in all viewing directions with Nz = 0.5 in both plates, which will greatly improve image quality of OLEDs.
Summary
Clonal cytopenia of undetermined significance (CCUS) is characterized by persistent cytopenias with genetic aberrations, which do not meet the diagnostic criteria for myelodysplastic syndrome ...(MDS). We aimed to compare the clinical and genetic characteristics of CCUS with lower‐risk MDS and identify patients with CCUS with a high risk of progression. We performed targeted sequencing of bone marrow (BM) samples from patients with idiopathic cytopenia of undetermined significance (ICUS) (n = 139) and MDS (n = 226). Overall survival (OS) of patients with CCUS (n = 78) was worse than non‐clonal ICUS (n = 61) and superior to lower‐risk MDS (n = 99). Patients with CCUS showed similar characteristics to those with lower‐risk MDS, except for higher haemoglobin, lower BM cellularity, and less frequent SF3B1 mutations. Lower haemoglobin, DDX41 (biallelic germline and somatic), ETV6, and RUNX1 mutations were independent prognostic factors for worse OS. Lower haemoglobin and DDX41 mutations were also associated with lower progression‐free survival. Patients with CCUS with high‐risk features showed similar or worse OS than patients with lower‐risk MDS. Our findings suggest that patients with CCUS having certain clinical or genetic features should be regarded and treated as lower‐risk MDS despite lacking significant dysplasia or MDS‐associated chromosomal abnormalities.
A simple, inexpensive and scalable method to prepare silicon‑carbon composite particles for use in all-solid-state Li-ion battery anodes is presented. The composite's electrochemically active ...soft-carbon matrix is formed through the pyrolysis of coal-tar-pitch, an abundant industrial waste material. Various techniques are used to characterize the physical and electrochemical properties of this pitch derived carbon. Optimization of the Si-C composite anode resulted in an all-solid-state Li-ion half-cell displaying stable specific capacities of 653.5 mAh/g (per mass electrode) and 1089.2 mAh/g (per mass Si-C composite) after 100 discharge-charge cycles. Cross sectional images of cycled electrodes, prepared via FIB milling, were taken in order to investigate the effect of silicon particle expansion on their composite microstructures.
•The pyrolysis of Coal-Tar-Pitch produces a mixed conducting amorphous carbon with impressive electrochemical properties.•A simple, inexpensive solution coating process is utilized to prepare carbon coated silicon anode materials.•Si-C composite particles are prepared using a variety of silicon powders.•All-solid-state Li-ion batteries constructed with the solution coated Si-C composites are optimized for extended performance.
DDX41 mutations are associated with hematologic malignancies including myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but the incidence in idiopathic cytopenia of undetermined ...significance (ICUS) is unknown. We investigated the incidence, genetic characteristics, and clinical features of DDX41 mutations in Korean patients with ICUS, MDS, or AML. We performed targeted deep sequencing of 61 genes including DDX41 in 457 patients with ICUS (n=75), MDS (n=210), or AML (n=172). Germline DDX41 mutations with causality were identified in 28 (6.1%) patients, of whom 27 (96.4%) had somatic mutations in the other position of DDX41. Germline origins of the DDX41 mutations were confirmed in all of the 11 patients in whom germline-based testing was performed. Of the germline DDX41 mutations, p.V152G (n=10) was most common, followed by p.Y259C (n=8), p.A500fs (n=6), and p.E7* (n=3). Compared with non-mutated patients, patients with a DDX41 mutation were more frequently male, older, had a normal karyotype, low leukocyte count, and hypocellular marrow at diagnosis. Three of the four ICUS patients with germline DDX41 mutations progressed to MDS. The incidence of DDX41 mutations in Korean patients was high and there was a distinct mutation pattern, in that p.V152G was a unique germline variant. ICUS harboring germline DDX41 mutations may be regarded as a hereditary myeloid neoplasm. Germline DDX41 mutations are not uncommon and should be explored when treating patients with myeloid malignancies.
Tryptanthrin 6,12-dihydro-6,12-dioxoindolo-(2,1-b)-quinazoline, originally isolated from Isatidis radix, has been characterized as having anti-microbial and anti-tumor activities. It is well-known ...that excess oxidative stress is one of the major factors causing cell damage in the liver. This study investigated the cytoprotective effects and molecular mechanism of tryptanthrin against tert-butyl hydroperoxide (tBHP)-induced oxidative stress in human hepatocyte-derived HepG2 cells. Tryptanthrin pre-treatment blocked the reactive oxygen species production, mitochondrial dysfunction, and cell death induced by tBHP. Moreover, tryptanthrin reversed tBHP-induced GSH reduction. This study also confirmed the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) by tryptanthrin as a plausible molecular mechanism for its cytoprotective effects. Specifically, tryptanthrin treatment induced nuclear translocation and transactivation of Nrf2 as well as phosphorylation of extracellular signal-regulated kinase (ERK), a potential upstream kinase of Nrf2. Tryptanthrin also up-regulated the expression of the heme oxygenase 1 and glutamate–cysteine ligase catalytic subunits, which are representative target genes of Nrf2. Moreover, inhibitor of ERK was used to verify the important role of the ERK-Nrf2 pathway in the hepatoprotective effects of tryptanthrin. In conclusion, this study demonstrated that tryptanthrin protects hepatocytes against oxidative stress through the activation of the ERK/Nrf2 pathway in HepG2 cells.
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