Women have a lower risk of hepatocellular carcinoma (HCC) than men, and the decreased possibility of HCC in women is thought to depend on estrogen levels. As a soybean-isoflavone product, genistein ...has estrogenic activity in various reproductive tissues, because it mimics 17β-estradiol and binds the estrogen receptor. Though genistein is a known liver cancer suppressor, its effects have not been studies in long-term experiment, where genistein is fed to a female animal model of HCC.
Mice were treated with diethylnitrosamine (DEN) to induce HCC at 2 weeks of age and fed with supplemental genistein for 5 months, from 40 to 62 weeks of age.
The dietary intake of genistein decreased the incidence of HCC and suppressed HCC development. Genistein induced phospho-AMPK in total liver extracts, Hep3B cells, and Raw 264.7 cells, and phospho-AMPK promoted apoptosis in liver and Hep3B cells. Moreover, phospho-AMPK down-regulated pro-inflammatory responses and ameliorated liver damage. A suppressed pro-inflammatory response with increased mitochondrial respiration was concomitantly observed after genistein treatment.
Genistein-mediated AMPK activation increases hepatocyte apoptosis through energy-dependent caspase pathways, suppresses the inflammatory response in resident liver macrophages by increased cellular respiration, and consequently inhibits the initiation and progression of HCC.
The endothelial cilium is a microtubule‐based organelle responsible for blood flow‐induced mechanosensation and signal transduction during angiogenesis. The precise function and mechanisms by which ...ciliary mechanosensation occurs, however, are poorly understood. Although posttranslational modifications (PTMs) of cytoplasmic tubulin are known to be important in angiogenesis, the specific roles of ciliary tubulin PTMs play remain unclear. Here, we report that loss of centrosomal protein 41 (CEP41) results in vascular impairment in human cell lines and zebrafish, implying a previously unknown pro‐angiogenic role for CEP41. We show that proper control of tubulin glutamylation by CEP41 is necessary for cilia disassembly and that is involved in endothelial cell (EC) dynamics such as migration and tubulogenesis. We show that in ECs responding to shear stress or hypoxia, CEP41 activates Aurora kinase A (AURKA) and upregulates expression of VEGFA and VEGFR2 through ciliary tubulin glutamylation, as well as leads to the deciliation. We further show that in hypoxia‐induced angiogenesis, CEP41 is responsible for the activation of HIF1α to trigger the AURKA‐VEGF pathway. Overall, our results suggest the CEP41‐HIF1α‐AURKA‐VEGF axis as a key molecular mechanism of angiogenesis and demonstrate how important ciliary tubulin glutamylation is in mechanosense‐responded EC dynamics.
Synopsis
CEP41 regulates cilia disassembly and angiogenesis through AURKA activation by modulating axonemal tubulin glutamylation in mammalian and zebrafish endothelial cells.
CEP41‐mediated axonemal tubulin glutamylation is essential for endothelial cell dynamics during angiogenesis.
CEP41 activates AURKA and upregulates VEGFA/VEGFR2 mRNAs to promote endothelia cellular deciliation under shear stress.
CEP41 interacts with HIF1α and inhibits its UPS‐dependent degradation under hypoxia.
CEP41 controls HIF1α activation to trigger AURKA‐VEGF pathway in hypoxia‐induced angiogenesis.
CEP41 regulates cilia disassembly and angiogenesis through AURKA activation by modulating axonemal tubulin glutamylation in mammalian and zebrafish endothelial cells.
In this study, we investigated the role of heat shock protein 70 (HSP70) in porcine epidemic diarrhoea virus (PEDV) replication. We found that PEDV infection induced strong HSP70 overexpression in ...the very early stage of infection. We also confirmed that HSP70 overexpression increased the speed of PEDV replication, resulting in the generation of more virions. In contrast, knockout of HSP70 in cells significantly downregulated PEDV protein expression, resulting in a significant reduction in PEDV replication. Most importantly, we confirmed that among the structural proteins of PEDV, membrane (M) proteins have this important role. We found that membrane proteins control cellular HSP70 expression in PEDV-infected cells. We confirmed HSP70/M complex formation by both immunoprecipitation and immunofluorescence assays. Additionally, PEDV M overexpression induced strong HSP70 expression. All our results clearly confirmed that in PEDV-infected cells, the M protein plays a very important role in PEDV replication in collaboration with HSP70.
In this study, we investigated the correlation between the mechanism involved in porcine epidemic diarrhea virus (PEDV) replication and autophagic flux. In this study, we found that as PEDV ...replicated, production of LC3-II was significantly induced up to 24 h post-infection (hpi). Interestingly, although there was significant production of LC3-II, greater p62 accumulation was simultaneously found. Pretreatment with rapamycin significantly induced PEDV replication, but autolysosome formation was reduced. These results were confirmed by the evaluation of ATG5/ATG12 and LAMP1/LAMP2. Taken together, we conclude that PEDV infection induces autophagosome formation but inhibits autolysosome formation during replication.
Background & Aims Little is known about whether surveillance for hepatocellular carcinoma (HCC) is worthwhile in chronic hepatitis B virus (HBV)-infected patients who have achieved HBsAg ...seroclearance. Methods A retrospective analysis of 829 patients (mean age: 52.3 years; 575 males; 98 with cirrhosis) achieving HBsAg seroclearance was performed at a tertiary hospital in Korea between 1997 and 2012. We evaluated incidence rates of HCC, and validated CU-HCC score based on data at the time of HBsAg seroclearance. Results During a follow-up of 3464 patient-years, 19 patients developed HCC (annual rate: 0.55%). Liver cirrhosis (hazard ratio HR: 10.80; 95% confidence interval CI: 4.25–27.43), male gender (HR: 8.96; 95% CI: 1.17–68.80), and age ⩾50 years at the time of HBsAg seroclearance (HR: 12.14; 95% CI: 1.61–91.68) were independently associated with HCC. The estimated annual incidence of HCC was 2.85% and 0.29% in patients with and without cirrhosis, respectively. Among the non-cirrhotic patients, the annual rate of HCC was higher in the male patients than in the females (0.40% vs. 0%, respectively), and all the HCCs developed after age 50. The time-dependent area under the receiver operating characteristic curves for the CU-HCC score for 5 year and 10 year HCC prediction were 0.85 and 0.74, respectively. Conclusions HCC surveillance should be considered for cirrhotic patients and non-cirrhotic male patients over age 50, even after HBsAg seroclearance, especially those infected with HBV genotype C. HBsAg seroclearance at age ⩾50 years was also an independent predictor for HCC.
Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a ...sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty‐five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine‐type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.
Pattern-recognition receptors including Toll-like receptors (TLRs) recognize invading pathogens and trigger an immune response in mammals. Here we show that mammalian ste20-like kinase ...1/serine/threonine kinase 4 (MST1/STK4) functions as a negative regulator of lipopolysaccharide (LPS)-induced activation of the TLR4-NF-κB signaling pathway associated with inflammation. Myeloid-specific genetic ablation of MST1/STK4 increased the susceptibility of mice to LPS-induced septic shock. Ablation of MST1/STK4 also enhanced NF-κB activation triggered by LPS in bone marrow-derived macrophages (BMDMs), leading to increased production of proinflammatory cytokines by these cells. Furthermore, MST1/STK4 inhibited TRAF6 autoubiquitination as well as TRAF6-mediated downstream signaling induced by LPS. In addition, we found that TRAF6 mediates the LPS-induced activation of MST1/STK4 by catalyzing its ubiquitination, resulting in negative feedback regulation by MST1/STK4 of the LPS-induced pathway leading to cytokine production in macrophages. Together, our findings suggest that MST1/STK4 functions as a negative modulator of the LPS-induced NF-κB signaling pathway during macrophage activation.
The nuclear factor (NF)-κB pathway plays a central role in inflammatory and immune responses, with aberrant activation of NF-κB signaling being implicated in various human disorders. Here, we show ...that mammalian ste20-like kinase 1 (MST1) is a previously unrecognized component of the tumor necrosis factor α (TNFα) receptor 1 signaling complex (TNF-RSC) and attenuates TNFα-induced NF-κB signaling. Genetic ablation of MST1 in mouse embryonic fibroblasts and bone marrow-derived macrophages potentiated the TNFα-induced increase in IκB kinase (IKK) activity, as well as the expression of NF-κB target genes. TNFα induced the recruitment of MST1 to TNF-RSC and its interaction with HOIP, the catalytic component of the E3 ligase linear ubiquitin assembly complex (LUBAC). Furthermore, MST1 activated in response to TNFα stimulation mediates the phosphorylation of HOIP and thereby inhibited LUBAC-dependent linear ubiquitination of NEMO/IKKγ. Together, our findings suggest that MST1 negatively regulates TNFα-induced NF-κB signaling by targeting LUBAC.
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•TNFα induces the recruitment of MST1 to the TNFR1 signaling complex (TNF-RSC)•TRAF2 is required for the TNFα-induced activation of MST1 within the TNF-RSC•MST1 phosphorylates HOIP in TNF-RSC, thereby inhibiting an E3 ligase activity of LUBAC•MST1 attenuates the LUBAC-mediated activation of the NF-κB pathway
Lee et al. identify MST1 as a component of TNF-RSC that phosphorylates HOIP at serine 1,066 and thereby inhibits the linear ubiquitin chain-forming activity of LUBAC in a TRAF2-dependent manner. MST1, by inhibiting an E3 ligase activity of HOIP, negatively regulates the NF-κB-dependent inflammatory gene expression induced by TNFα.
The placenta regulates maternal-fetal communication, and its defect leads to significant pregnancy complications. The maternal and embryonic circulations are primitively connected in early ...placentation, but the function of the placenta during this developmentally essential period is relatively unknown. We thus performed a comparative proteomic analysis of the placenta before and after primary placentation and found that the metabolism and transport of lipids were characteristically activated in this period. The placental fatty acid (FA) carriers in specific placental compartments were upregulated according to gestational age, and metabolomic analysis also showed that the placental transport of FAs increased in a time-dependent manner. Further analysis of two mutant mice models with embryonic lethality revealed that lipid-related signatures could reflect the functional state of the placenta. Our findings highlight the importance of the nutrient transport function of the primary placenta in the early gestational period and the role of lipids in embryonic development. Summary Sentence The placenta is activated characteristically in terms of lipid transport during primary placentation, and the lipid-related signatures closely reflect the functional state of the placenta.
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