Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
24 result(s) for "Lourie, Rohan"
Sort by:
The interplay between endoplasmic reticulum stress and inflammation
Endoplasmic reticulum (ER) stress may be both a trigger and consequence of chronic inflammation. Chronic inflammation is often associated with diseases that arise because of primary misfolding mutations and ER stress. Similarly, ER stress and activation of the unfolded protein response (UPR) is a feature of many chronic inflammatory and autoimmune diseases. In this review, we describe how protein misfolding and the UPR trigger inflammation, how environmental ER stressors affect antigen presenting cells and immune effector cells, and present evidence that inflammatory factors exacerbate protein misfolding and ER stress. Examples from both animal models of disease and human diseases are used to illustrate the complex interactions between ER stress and inflammation, and opportunities for therapeutic targeting are discussed. Finally, recommendations are made for future research with respect to the interaction of ER stress and inflammation. Autoimmunity occurs when an organism develops an immune response against itself, resulting in an inflammatory reaction which damages organs such as brain, joints or pancreas. This results in diseases such as Type 1 diabetes, vasculitis, or rheumatoid arthritis. A fine balance exists in order to accommodate the control of microbial pathogens and commensals, and immune self‐tolerance. The March 2012 issue will include a review series on Autoimmune Disease, particularly featuring articles on clinical translation, and the current state of research in this area. Articles include reasons for the increased incidence of certain autoimmune diseases and allergic diseases in Western society and the advances made by the application of novel and high throughput technologies to the analysis of diseased tissues. The accompanying web focus presents links to related articles from across Nature Publishing Group.
CDCP1 enhances Wnt signaling in colorectal cancer promoting nuclear localization of β-catenin and E-cadherin
Elevated CUB-domain containing protein 1 (CDCP1) is predictive of colorectal cancer (CRC) recurrence and poor patient survival. While CDCP1 expression identifies stem cell populations that mediate lung metastasis, mechanisms underlying the role of this cell surface receptor in CRC have not been defined. We sought to identify CDCP1 regulated processes in CRC using stem cell populations, enriched from primary cells and cell lines, in extensive in vitro and in vivo assays. These experiments, demonstrating that CDCP1 is functionally important in CRC tumor initiation, growth and metastasis, identified CDCP1 as a positive regulator of Wnt signaling. Detailed cell fractionation, immunoprecipitation, microscopy, and immunohistochemical analyses demonstrated that CDCP1 promotes translocation of the key regulators of Wnt signaling, β-catenin, and E-cadherin, to the nucleus. Of functional importance, disruption of CDCP1 reduces nuclear localized, chromatin-associated β-catenin and nuclear localized E-cadherin, increases sequestration of these proteins in cell membranes, disrupts regulation of CRC promoting genes, and reduces CRC tumor burden. Thus, disruption of CDCP1 perturbs pro-cancerous Wnt signaling including nuclear localization of β-catenin and E-cadherin.
Immune-driven alterations in mucin sulphation is an important mediator of Trichuris muris helminth expulsion
Mucins are heavily glycosylated proteins that give mucus its gel-like properties. Moreover, the glycans decorating the mucin protein core can alter the protective properties of the mucus barrier. To investigate whether these alterations could be parasite-induced we utilized the Trichuris muris (T. muris) infection model, using different infection doses and strains of mice that are resistant (high dose infection in BALB/c and C57BL6 mice) or susceptible (high dose infection in AKR and low dose infection in BALB/c mice) to chronic infection by T. muris. During chronicity, within the immediate vicinity of the T. muris helminth the goblet cell thecae contained mainly sialylated mucins. In contrast, the goblet cells within the epithelial crypts in the resistant models contained mainly sulphated mucins. Maintained mucin sulphation was promoted by TH2-immune responses, in particular IL-13, and contributed to the protective properties of the mucus layer, making it less vulnerable to degradation by T. muris excretory secretory products. Mucin sulphation was markedly reduced in the caecal goblet cells in the sulphate anion transporter-1 (Sat-1) deficient mice. We found that Sat-1 deficient mice were susceptible to chronic infection despite a strong TH2-immune response. Lower sulphation levels lead to decreased efficiency of establishment of T. muris infection, independent of egg hatching. This study highlights the complex process by which immune-regulated alterations in mucin glycosylation occur following T. muris infection, which contributes to clearance of parasitic infection.
The MUC13 cell-surface mucin protects against intestinal inflammation by inhibiting epithelial cell apoptosis
Background and AimsThe MUC13 transmembrane mucin is highly and constitutively expressed in the small and large intestine. Although MUC13 polymorphisms have been associated with human inflammatory bowel diseases and susceptibility to Escherichia coli infection in pigs, the biological functions of MUC13 are unknown. This study aimed to explore whether MUC13 modulates intestinal inflammation.MethodsMuc13−/− mice were generated, phenotyped and challenged with the colitis-inducing agent, dextran sodium sulphate (DSS). Colitis was assessed by clinical symptoms and intestinal histopathology. Intestinal epithelial cell apoptosis and proliferation, macrophage infiltration and cytokine production were also quantified. Apoptosis of human LS513 intestinal epithelial cells in response to apoptotic agents, including DSS, was also measured, following knockdown of MUC13 with siRNA.ResultsMuc13−/− mice were viable, fertile and developed normally, with no spontaneous intestinal pathology except mild focal neutrophilic inflammation in the small and large intestines of old mice. In response to DSS challenge, Muc13−/− mice developed more severe acute colitis, as reflected by increased weight loss, rectal bleeding, diarrhoea and histological colitis scores compared with wild-type mice. Increased numbers of F4/80+ macrophages in inflamed mucosa of Muc13−/− mice were accompanied by increased expression of intestinal IL-1β and TNFα mRNA. Muc13−/− mice had significantly increased intestinal epithelial cell apoptosis within 3 days of DSS exposure. LS513 cells were more susceptible to DSS, actinomycin-D, ultraviolet irradiation and TRAIL-induced apoptosis when MUC13 was knocked down by siRNA.ConclusionsThese novel findings indicate a protective role for Muc13 in the colonic epithelium by inhibiting toxin-induced apoptosis and have important implications for intestinal infections, inflammatory diseases and the development of intestinal cancer.
Endometrial cancer PDX-derived organoids (PDXOs) and PDXs with FGFR2c isoform expression are sensitive to FGFR inhibition
Endometrial cancer (EC) patients with metastatic/recurrent disease have limited treatment options and poor survival outcomes. Recently, we discovered the FGFR2c splice isoform is associated with poor prognosis in EC patients. Here we report the establishment of 16 EC patient-derived xenografts (PDX)-derived organoids (PDXOs) with or without FGFR2c expression. In vitro treatment of 5 EC PDXOs with BGJ398 showed significant cell death in 3 models with FGFR2c expression. PDXs with high/moderate FGFR2c expression showed significant tumour growth inhibition (TGI) following 21-day treatment with FGFR inhibitors (BGJ398 or pemigatinib) and significantly prolonged survival in 4/5 models. Pemigatinib + cisplatin combination therapy ( n  = 5) resulted in significant TGI and prolonged survival in one of two p53abn PDXs. All five models treated with cisplatin alone showed de novo resistance and no survival benefit. Seven-day treatment with BGJ398 revealed a significant reduction in angiogenesis and CD206 + M2 macrophages. These data collectively support the evaluation of FGFR inhibitors in a clinical trial.
UGDH promotes tumor-initiating cells and a fibroinflammatory tumor microenvironment in ovarian cancer
Background Epithelial ovarian cancer (EOC) is a global health burden, with the poorest five-year survival rate of the gynecological malignancies due to diagnosis at advanced stage and high recurrence rate. Recurrence in EOC is driven by the survival of chemoresistant, stem-like tumor-initiating cells (TICs) that are supported by a complex extracellular matrix and immunosuppressive microenvironment. To target TICs to prevent recurrence, we identified genes critical for TIC viability from a whole genome siRNA screen. A top hit was the cancer-associated, proteoglycan subunit synthesis enzyme UDP-glucose dehydrogenase (UGDH). Methods Immunohistochemistry was used to characterize UGDH expression in histological and molecular subtypes of EOC. EOC cell lines were subtyped according to the molecular subtypes and the functional effects of modulating UGDH expression in vitro and in vivo in C1/Mesenchymal and C4/Differentiated subtype cell lines was examined. Results High UGDH expression was observed in high-grade serous ovarian cancers and a distinctive survival prognostic for UGDH expression was revealed when serous cancers were stratified by molecular subtype. High UGDH was associated with a poor prognosis in the C1/Mesenchymal subtype and low UGDH was associated with poor prognosis in the C4/Differentiated subtype. Knockdown of UGDH in the C1/mesenchymal molecular subtype reduced spheroid formation and viability and reduced the CD133 + /ALDH high TIC population. Conversely, overexpression of UGDH in the C4/Differentiated subtype reduced the TIC population. In co-culture models, UGDH expression in spheroids affected the gene expression of mesothelial cells causing changes to matrix remodeling proteins, and fibroblast collagen production. Inflammatory cytokine expression of spheroids was altered by UGDH expression. The effect of UGDH knockdown or overexpression in the C1/ Mesenchymal and C4/Differentiated subtypes respectively was tested on mouse intrabursal xenografts and showed dynamic changes to the tumor stroma. Knockdown of UGDH improved survival and reduced tumor burden in C1/Mesenchymal compared to controls. Conclusions These data show that modulation of UGDH expression in ovarian cancer reveals distinct roles for UGDH in the C1/Mesenchymal and C4/Differentiated molecular subtypes of EOC, influencing the tumor microenvironmental composition. UGDH is a strong potential therapeutic target in TICs, for the treatment of EOC, particularly in patients with the mesenchymal molecular subtype.
Scalable Engineering of Bio‐Manufactured Extracellular Vesicles for Selective Delivery in Ovarian Cancer Patient‐Derived Models
Ovarian cancer remains challenging to treat because of late diagnosis, heterogeneity, and poor response to existing therapies. Here, we present a streamlined and scalable extracellular vesicle (EV) engineering approach that enables efficient cargo packaging and enhances targeted cargo delivery to ovarian tumors in vivo. Systematic comparison of vesicle‐anchoring domains identifies an optimized scaffold for loading bioluminescent cargo into EVs. We characterized EV production from five cell lines commonly used for biopharmaceutical manufacturing and selected and stably engineered ExpiCHO cells as a robust, large‐scale source of engineered EVs (eEVs). To achieve molecular targeting, the transmembrane scaffold Δ688 PTGFRN is modified to display tissue‐targeting ligand Ephrin‐B2 (EB2) on the EV surface, exploiting its high‐affinity interaction with the Eph receptor B4 (EphB4), which is overexpressed in advanced ovarian carcinoma. Following systemic administration, these eEVs carrying bioluminescent cargo preferentially accumulate in EphB4‐positive cells in vivo and permit non‐invasive, spatiotemporal tracking via cargo‐mediated bioluminescence resonance energy transfer. In patient‐derived xenograft models with differential EphB4 expression, Ephrin‐B2–displaying eEVs show selective localization to EphB4‐positive tumors and report intratumoral cargo distribution. This work establishes a translational strategy for large‐scale eEV production, advancing EV‐based delivery platforms for precision targeting of EphB4‐expressing ovarian cancer. Engineered extracellular vesicles displaying Ephrin‐B2 selectively target Ephrin‐B4–expressing ovarian cancer cells, enabling precise delivery in patient‐derived models. This scalable bio‐manufacturing platform reveals a versatile strategy to exploit Ephrin signaling for highly specific therapeutic payload delivery and motivates exploration of tailored EV‐based interventions in heterogeneous ovarian tumours.
Adult Non-Cystic Fibrosis Bronchiectasis Is Characterised by Airway Luminal Th17 Pathway Activation
Non-cystic fibrosis (CF) bronchiectasis is characterised by chronic airway infection and neutrophilic inflammation, which we hypothesised would be associated with Th17 pathway activation. Th17 pathway cytokines were quantified in bronchoalveolar lavage fluid (BALF), and gene expression of IL-17A, IL-1β, IL-8 and IL-23 determined from endobronchial biopsies (EBx) in 41 stable bronchiectasis subjects and 20 healthy controls. Relationships between IL-17A levels and infection status, important clinical measures and subsequent Pseudomonas aeruginosa infection were determined. BALF levels of all Th17 cytokines (median (IQR) pg/mL) were significantly higher in bronchiectasis than control subjects, including IL-17A (1.73 (1.19, 3.23) vs. 0.27 (0.24, 0.35), 95% CI 1.05 to 2.21, p<0.0001) and IL-23 (9.48 (4.79, 15.75) vs. 0.70 (0.43, 1.79), 95% CI 4.68 to 11.21, p<0.0001). However, BALF IL-17A levels were not associated with clinical measures or airway microbiology, nor predictive of subsequent P. aeruginosa infection. Furthermore, gene expression of IL-17A in bronchiectasis EBx did not differ from control. In contrast, gene expression (relative to medians of controls) in bronchiectasis EBx was significantly higher than control for IL1β (4.12 (1.24, 8.05) vs 1 (0.13, 2.95), 95% CI 0.05 to 4.07, p = 0.04) and IL-8 (3.75 (1.64, 11.27) vs 1 (0.54, 3.89), 95% CI 0.32 to 4.87, p = 0.02) and BALF IL-8 and IL-1α levels showed significant relationships with clinical measures and airway microbiology. P. aeruginosa infection was associated with increased levels of IL-8 while Haemophilus influenzae was associated with increased IL-1α. Established adult non-CF bronchiectasis is characterised by luminal Th17 pathway activation, however this pathway may be relatively less important than activation of non-antigen-specific innate neutrophilic immunity.
Disruption of Glycogen Utilization Markedly Improves the Efficacy of Carboplatin against Preclinical Models of Clear Cell Ovarian Carcinoma
High stage and recurrent ovarian clear cell carcinoma (OCC) are associated with poor prognosis and resistance to chemotherapy. A distinguishing histological feature of OCC is abundant cytoplasmic stores of glucose, in the form of glycogen, that can be mobilized for cellular metabolism. Here, we report the effect on preclinical models of OCC of disrupting glycogen utilization using the glucose analogue 2-deoxy-D-glucose (2DG). At concentrations significantly lower than previously reported for other cancers, 2DG markedly improves the efficacy in vitro of carboplatin chemotherapy against chemo-sensitive TOV21G and chemo-resistant OVTOKO OCC cell lines, and this is accompanied by the depletion of glycogen. Of note, 2DG doses—of more than 10-fold lower than previously reported for other cancers—significantly improve the efficacy of carboplatin against cell line and patient-derived xenograft models in mice that mimic the chemo-responsiveness of OCC. These findings are encouraging, in that 2DG doses, which are substantially lower than previously reported to cause adverse events in cancer patients, can safely and significantly improve the efficacy of carboplatin against OCC. Our results thus justify clinical trials to evaluate whether low dose 2DG improves the efficacy of carboplatin in OCC patients.
High Fat Diets Induce Colonic Epithelial Cell Stress and Inflammation that is Reversed by IL-22
Prolonged high fat diets (HFD) induce low-grade chronic intestinal inflammation in mice, and diets high in saturated fat are a risk factor for the development of human inflammatory bowel diseases. We hypothesized that HFD-induced endoplasmic reticulum (ER)/oxidative stress occur in intestinal secretory goblet cells, triggering inflammatory signaling and reducing synthesis/secretion of proteins that form the protective mucus barrier. In cultured intestinal cells non-esterified long-chain saturated fatty acids directly increased oxidative/ER stress leading to protein misfolding. A prolonged HFD elevated the intestinal inflammatory cytokine signature, alongside compromised mucosal barrier integrity with a decrease in goblet cell differentiation and Muc2, a loss in the tight junction protein, claudin-1 and increased serum endotoxin levels. In Winnie mice, that develop spontaneous colitis, HFD-feeding increased ER stress, further compromised the mucosal barrier and increased the severity of colitis. In obese mice IL-22 reduced ER/oxidative stress and improved the integrity of the mucosal barrier, and reversed microbial changes associated with obesity with an increase in Akkermansia muciniphila . Consistent with epidemiological studies, our experiments suggest that HFDs are likely to impair intestinal barrier function, particularly in early life, which partially involves direct effects of free-fatty acids on intestinal cells, and this can be reversed by IL-22 therapy.