Androgen and its receptor (AR) have been reported to have pro-or antiapoptotic functions. However, the underlying molecular mechanism is incompletely understood. We report here that androgen and AR promote Bax-mediated apoptosis in prostate cancer cells. UV irradiation and ectopic expression of Bax induce apoptosis in AR-positive, but not AR-negative prostate cancer cells. UV-and Bax-induced apoptosis is abrogated in AR-positive cells that express small interference RNA (siRNA) of AR and is sensitized by reintroduction of AR into AR-negative cells. Although AR is able to promote Bax-mediated apoptosis independently of androgen, the promotion by AR can be further potentiated by androgen via AR-dependent transcription activation. AR is essential for the translocation of Bax to mitochondria in UV-or Bax-induced apoptosis. Inhibition of Bax expression by Bax siRNA suppresses UV-induced apoptosis in AR-positive cells. In addition, introduction of AR into AR-negative prostate cancer cells upregulates expression levels of the BH3-only protein Noxa, whereas inhibition of Noxa expression reduces the promotion by AR on UV-induced apoptosis. Thus, our results reveal a novel cross talk between the androgen/AR hormonal signaling pathway and the intrinsic apoptotic death pathway that determines the sensitivity of stress-induced apoptosis in prostate cancer cells.
Feline infectious peritonitis (FIP), caused by a mutated feline coronavirus, is one of the most serious and fatal viral diseases in cats. The disease remains incurable, and there is no effective vaccine available. In light of the pathogenic mechanism of feline coronavirus that relies on endosomal acidification for cytoplasmic entry, a novel vacuolar ATPase blocker, diphyllin, and its nanoformulation are herein investigated for their antiviral activity against the type II feline infectious peritonitis virus (FIPV). Experimental results show that diphyllin dose-dependently inhibits endosomal acidification in fcwf-4 cells, alters the cellular susceptibility to FIPV, and inhibits the downstream virus replication. In addition, diphyllin delivered by polymeric nanoparticles consisting of poly(ethylene glycol)-block-poly(lactide-co-glycolide) (PEG-PLGA) further demonstrates an improved safety profile and enhanced inhibitory activity against FIPV. In an in vitro model of antibody-dependent enhancement of FIPV infection, diphyllin nanoparticles showed a prominent antiviral effect against the feline coronavirus. In addition, the diphyllin nanoparticles were well tolerated in mice following high-dose intravenous administration. This study highlights the therapeutic potential of diphyllin and its nanoformulation for the treatment of FIP.
Attachment to cellular surfaces is a major attribute among infectious pathogens for initiating disease pathogenesis. In viral infections, viruses exploit receptor-ligand interactions to latch onto cellular exterior prior to subsequent entry and invasion. In light of the selective binding affinity between viral pathogens and cells, nanoparticles cloaked in cellular membranes are herein employed for virus targeting. Using the influenza virus as a model, erythrocyte membrane cloaked nanoparticles are prepared and modified with magnetic functionalities (RBC-mNP) for virus targeting and isolation. To maximize targeting and isolation efficiency, density gradient centrifugation and nanoparticle tracking analysis were applied to minimize the presence of uncoated particles and membrane vesicles. The resulting nanoparticles possess a distinctive membrane corona, a sialylated surface, and form colloidally stable clusters with influenza viruses. Magnetic functionality is bestowed to the nanoparticles through encapsulation of superparamagnetic iron-oxide particles, which enable influenza virus enrichment via magnetic extraction. Viral samples enriched by the RBC-mNPs result in significantly enhanced virus detection by multiple virus quantification methods, including qRT-PCR, immunnochromatographic strip test, and cell-based titering assays. The demonstration of pathogen targeting and isolation by RBC-mNPs highlights a biologically inspired approach toward improved treatment and diagnosis against infectious disease threats. The work also sheds light on the efficient membrane cloaking mechanism that bestows nanoparticles with cell mimicking functionalities.
Literature about healthcare-associated infection (HCAI) in China is scarce. A cross-sectional anonymous survey was conducted on 647 clinicians (199 physicians and 448 nurses) from six Shanghai hospitals (grades A–C) to investigate their cognizance, knowledge, attitude, self-reported practice, and risks regarding HCAI with emphasis on precautions. The mean overall score of HCAI knowledge was 40.89±11.4 (mean±SD; range, 13∼72) out of 100 for physicians and 43.48±9.9 (10∼70) for nurses. The respondents generally received high scores in hand hygiene, HCAI core concept, and healthcare worker safety but low scores in HCAI pathogen identification and isolation precautions. There were substantial variations in the knowledge scores of various demographic groups across individual hospitals and within hospital grades (ps<0.05). Within-hospital comparisons showed that the nurses were better than physicians particularly in hand hygiene knowledge in 4 hospitals (ps<0.05). Multiple linear regression analysis showed that longer work experience was inversely and independently associated with the overall and categorical knowledge of nurses, whereas independent associations between older age or higher education and categorical knowledge were noted for physicians. The respondents' self-reported practices and adherence to standard precautions were less than satisfactory. This multi-center study reports a high level of cognizance, patchy knowledge, suboptimal adherence to infection control precautions, and self-protective attitudes among the practicing clinicians regarding HCAI, with potential safety risk to patients and healthcare providers. Providing quality learning resources, enforcing knowledge-informed practice, and promoting a healthcare safety culture are recommended as interventions. Future studies are warranted for social and behavioral aspects of healthcare safety with emphasis on infection control.
l-Stepholidine (SPD) is a tetrahydroprotoberberine alkaloid and a mixed dopamine D1 agonist/D2 antagonist. Preliminary clinical trials suggest that SPD improves both positive and negative symptoms of schizophrenia without producing significant extrapyramidal side effects. Here, we report that SPD mimics the effect of the atypical antipsychotic drug clozapine, preferentially increasing Fos expression in corticolimbic areas. Thus, at 10 mg/kg (i.p.), SPD induced Fos expression in the medial prefrontal cortex (mPFC), nucleus accumbens (NAc), and lateral septal nucleus (LSN) without significantly affecting the dorsolateral striatum (DLSt). At higher doses (20-40 mg/kg), SPD also increased Fos expression in the DLSt. The increase, however, was less pronounced than the increase seen in the NAc. Within the NAc, SPD also induced more Fos expression in the shell than in the core. In all subcortical areas examined, the Fos expression induced by SPD was mimicked by the D2 antagonist sulpiride and reversed by the D2 agonist quinpirole, suggesting that the effect is due to blockade of D2-like receptors by SPD. In the mPFC, however, the effect was not mimicked by sulpride or reversed by quinpirole. It was also not mimicked by the D1 agonist SKF38393 or SKF38393 plus sulpride, and not reversed by the D1 antagonist SCH23390. These results suggest that, in the mPFC, SPD may induce Fos expression through a non-DA mechanism. Whether the mechanism involves an interaction of SPD with other neurotransmitters such as 5-HT and norepinephrine remains to be determined.
Abstract:The signaling cascades of the mitogen activated protein kinase (MAPK) family, calcineurin/NFATc4, and PI3K/Akt/GSK3, are believed to participate in endothelin-1 (ET-1)-induced cardiac hypertrophy. The aim of this study was to investigate whether KMUP-1, a synthetic xanthine-based derivative, prevents cardiomyocyte hypertrophy induced by ET-1 and to elucidate the underlying mechanisms. We found that in H9c2 cardiomyocytes, stimulation with ET-1 (100 nM) for 4 days induced cell hypertrophy and enhanced expressions of hypertrophic markers, including atrial natriuretic peptide and brain natriuretic peptide, which were all inhibited by KMUP-1 in a dose-dependent manner. In addition, KMUP-1 prevented ET-1-induced intracellular reactive oxygen species generation determined by the DCFH-DA assay in cardiomyocytes. KMUP-1 also attenuated phosphorylation of ERK1/2 and Akt/GSK-3β, and activation of calcineurin/NFATc4 and RhoA/ROCK pathways induced by ET-1. Furthermore, we found that the expression of heme oxygenase-1 (HO-1), a stress-response enzyme implicated in cardio-protection, was OPEN ACCESSMolecules 2015, 20 10436 up-regulated by KMUP-1. Finally, KMUP-1 attenuated ET-1-stimulated activator protein-1 DNA binding activity. In conclusion, KMUP-1 attenuates cardiomyocyte hypertrophy induced by ET-1 through inhibiting ERK1/2, calcineurin/NFATc4 and RhoA/ROCK pathways, with associated cardioprotective effects via HO-1 activation. Therefore, KMUP-1 may have a role in pharmacological therapy of cardiac hypertrophy.
DDIT4 is a mitochondrial and tumor-related protein involved in anti-tumor therapy resistance, proliferation, and invasion, etc. Its expression level increases under the stress such as chemotherapy, hypoxia, and DNA damage. A number of clinical studies have confirmed that DDIT4 can change the behavior of tumor cells and the prognosis of patients with cancer. However, the role of DDIT4 in promoting or suppressing cancer is still inconclusive. This article summarized the four characteristics of DDIT4 including a mitochondria-related protein, interactions with various protein molecules, immune and metabolic cell related proteins and participator in the oxygen sensing pathway, which may be related to the progress of cancer.
Ovarian cancer is currently one of the most common cancers of the female reproductive organs, and its mortality rate is the highest among all types of gynecologic cancers. Rapid and accurate classification of ovarian cancer plays an important role in the determination of treatment plans and prognoses. Nevertheless, the most commonly used classification method is based on histopathological specimen examination, which is time‐consuming and labor‐intensive. Thus, in this study, we utilize radiomics feature extraction methods and the automated machine learning tree‐based pipeline optimization tool (TOPT) for analysis of 3D, second harmonic generation images of benign, malignant and normal human ovarian tissues, to develop a high‐efficiency computer‐aided diagnostic model. Area under the receiver operating characteristic curve values of 0.98, 0.96 and 0.94 were obtained, respectively, for the classification of the three tissue types. Furthermore, this approach can be readily applied to other related tissues and diseases, and has great potential for improving the efficiency of medical diagnostic processes.
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