16 research outputs found

    Hedgehog overexpression leads to the formation of prostate cancer stem cells with metastatic property irrespective of androgen receptor expression in the mouse model

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    <p>Abstract</p> <p>Background</p> <p>Hedgehog signalling has been implicated in prostate tumorigenesis in human subjects and mouse models, but its effects on transforming normal basal/stem cells toward malignant cancer stem cells remain poorly understood.</p> <p>Methods</p> <p>We produced pCX-shh-IG mice that overexpress Hedgehog protein persistently in adult prostates, allowing for elucidation of the mechanism during prostate cancer initiation and progression. Various markers were used to characterize and confirm the transformation of normal prostate basal/stem cells into malignant cancer stem cells under the influence of Hedgehog overexpression.</p> <p>Results</p> <p>The pCX-shh-IG mice developed prostatic intraepithelial neoplasia (PIN) that led to invasive and metastatic prostate cancers within 90 days. The prostate cancer was initiated through activation of P63<sup>+ </sup>basal/stem cells along with simultaneous activation of Hedgehog signalling members, suggesting that P63<sup>+</sup>/Patch1<sup>+ </sup>and P63<sup>+</sup>/Smo<sup>+ </sup>cells may serve as cancer-initiating cells and progress into malignant prostate cancer stem cells (PCSCs). In the hyperplastic lesions and tumors, the progeny of PCSCs differentiated into cells of basal-intermediate and intermediate-luminal characteristics, whereas rare ChgA<sup>+ </sup>neuroendocrine differentiation was seen. Furthermore, in the metastatic loci within lymph nodes, kidneys, and lungs, the P63<sup>+ </sup>PCSCs formed prostate-like glandular structures, characteristic of the primitive structures during early prostate development. Besides, androgen receptor (AR) expression was detected heterogeneously during tumor progression. The existence of P63<sup>+</sup>/AR<sup>-</sup>, CK14<sup>+</sup>/AR<sup>- </sup>and CD44<sup>+</sup>/AR<sup>- </sup>progeny indicates direct procurement of AR<sup>- </sup>malignant cancer trait.</p> <p>Conclusions</p> <p>These data support a cancer stem cell scenario in which Hedgehog signalling plays important roles in transforming normal prostate basal/stem cells into PCSCs and in the progression of PCSCs into metastatic tumor cells.</p

    Automatic Segmentation of Retinal Fluid and Photoreceptor Layer from Optical Coherence Tomography Images of Diabetic Macular Edema Patients Using Deep Learning and Associations with Visual Acuity

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    Diabetic macular edema (DME) is a highly common cause of vision loss in patients with diabetes. Optical coherence tomography (OCT) is crucial in classifying DME and tracking the results of DME treatment. The presence of intraretinal cystoid fluid (IRC) and subretinal fluid (SRF) and the disruption of the ellipsoid zone (EZ), which is part of the photoreceptor layer, are three crucial factors affecting the best corrected visual acuity (BCVA). However, the manual segmentation of retinal fluid and the EZ from retinal OCT images is laborious and time-consuming. Current methods focus only on the segmentation of retinal features, lacking a correlation with visual acuity. Therefore, we proposed a modified U-net, a deep learning algorithm, to segment these features from OCT images of patients with DME. We also correlated these features with visual acuity. The IRC, SRF, and EZ of the OCT retinal images were manually labeled and checked by doctors. We trained the modified U-net model on these labeled images. Our model achieved S&oslash;rensen&ndash;Dice coefficients of 0.80 and 0.89 for IRC and SRF, respectively. The area under the receiver operating characteristic curve (ROC) for EZ disruption was 0.88. Linear regression indicated that EZ disruption was the factor most strongly correlated with BCVA. This finding agrees with that of previous studies on OCT images. Thus, we demonstrate that our segmentation network can be feasibly applied to OCT image segmentation and assist physicians in assessing the severity of the disease

    Tamm Plasmon Polaritons Hydrogen Sensors

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    Abstract Tamm plasmon polariton (TPP) resonance can be excited within the stopband of a distributed Bragg reflector (DBR) by combining a thin metal film. When exposured to hydrogen gas, the TPP resonance feature is redshifted for the TPPs structure with palladium (Pd) on the top, due to hydrogen‐induced palladium lattice expansion. By utilizing a DBR‐side TPP structure, near‐zero reflectance can be achieved, leading to more than 3 orders of magnitude changes in reflectance compared to metal‐side TPP structure. The proposed TPP hydrogen structure enables the detection with low H2 concentration from 0.5% to 4%. Comparing to the only Pd film, TPP sensor has increased the sensitivity about 100% at visible wavelengths

    The anti-TH17 polarization effect of Indigo naturalis and tryptanthrin by differentially inhibiting cytokine expression

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    Ethnopharmacological relevance: The Chinese herbal medicine Qing-Dai (also known as Indigo naturalis) extracted from indigo-bearing plants including Baphicacanthus cusia (Ness) Bremek was previously reported to exhibit anti-psoriatic effects in topical treatment. TH17 was later established as a key player in the pathogenesis of psoriasis. We investigated the anti-TH17 effect of Indigo naturalis and its active compounds. The aim of this study is to evaluate the toxicity of Indigo naturalis (IN) and its derivatives on five cell types involved in psoriasis, and to study the anti-inflammatory mechanism for the toxicity. Materials and methods: Following the fingerprint and quantity analysis of indirubin, indigo, and tryptanthrin in IN extract, we used MTS kits to measure the anti-proliferative effect of IN and three active compounds on five different cell types identified in psoriatic lesions. Quantitative RT-PCR analysis was used to measure the expression of various genes identified in the activated keratinocytes and TH17 polarized gene expression in RORÎłt-expressing T cells. Results: We showed that IN differentially inhibited the proliferation of keratinocytes and endothelial cells but not monocytes, fibroblasts nor Jurkat T cells. Among three active compounds identified in IN, tryptanthrin was the most potent compound to reduce their proliferation. In addition to differentially reducing IL6 and IL8 expression, both IN and tryptanthrin also potently decreased the expression of anti-microbial S100A9 peptide, CCL20 chemokine, IL1B and TNFA cytokines, independent of NF-ÎșB-p65-activation. Their attenuating effect was also detected on the expression of signature cytokines or chemokines induced during RORÎłT-induced TH17 polarization. Conclusions: We were the first to confirm a direct anti-TH17 effect of both IN herbal extract and tryptanthrin

    Targeting and Enrichment of Viral Pathogen by Cell Membrane Cloaked Magnetic Nanoparticles for Enhanced Detection

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    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

    Yeast Cip1 is activated by environmental stress to inhibit Cdk1–G1 cyclins via Mcm1 and Msn2/4

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    Upon environmental changes, proliferating cells delay cell cycle to prevent further damage accumulation. Yeast Cip1 is a Cdk1 and Cln2-associated protein. However, the function and regulation of Cip1 are still poorly understood. Here we report that Cip1 expression is co-regulated by the cell-cycle-mediated factor Mcm1 and the stress-mediated factors Msn2/4. Overexpression of Cip1 arrests cell cycle through inhibition of Cdk1-G1 cyclin complexes at G1 stage and the stress-activated protein kinase-dependent Cip1 T65, T69, and T73 phosphorylation may strengthen the Cip1and Cdk1-G1 cyclin interaction. Cip1 accumulation mainly targets Cdk1-Cln3 complex to prevent Whi5 phosphorylation and inhibit early G1 progression. Under osmotic stress, Cip1 expression triggers transient G1 delay which plays a functionally redundant role with another hyperosmolar activated CKI, Sic1. These findings indicate that Cip1 functions similarly to mammalian p21 as a stress-induced CDK inhibitor to decelerate cell cycle through G1 cyclins to cope with environmental stresses.A G1 cell cycle regulatory kinase Cip1 has been identified in budding yeast but how this is regulated is unclear. Here the authors identify cell cycle (Mcm1) and stress-mediated (Msn 2/4) transcription factors as regulating Cip1, causing stress induced CDK inhibition and delay in cell cycle progression
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