Time filter

Source Type

Evanston, IL, United States

Arias M.A.,University of Zaragoza | JimenezdeBagues M.P.,CSIC - Centro de Investigacion y Tecnologia Agroalimentaria | Aguilo N.,University of Zaragoza | Menao S.,HCU Lozano Blesa | And 6 more authors.
Cell Reports | Year: 2014

During bacterial sepsis, proinflammatory cytokines contribute to multiorgan failure and death in a process regulated in part by cytolytic cell granzymes. When challenged with a sublethal dose of the identified mouse pathogen Brucella microti, wild-type (WT) and granzyme A (gzmA)-/- mice eliminate the organism from liver and spleen in 2 or 3weeks, whereas the bacteria persist in mice lacking perforin or granzyme B as well as in mice depleted of Tc cells. In comparison, after a fatal challenge, only gzmA-/- mice exhibit increased survival, which correlated with reduced proinflammatory cytokines. Depletion of natural killer (NK) cells protects WT mice from sepsis without influencing bacterial clearance and the transfer of WT, but not gzmA-/- NK, cells into gzmA-/- recipients restores the susceptibility to sepsis. Therefore, infection-related pathology, but not bacterial clearance, appears to require gzmA, suggesting the protease may be a therapeutic target for the prevention of bacterial sepsis without affecting immune control of the pathogen. © 2014 The Authors. Source

Qi W.,NorthShore University Research Institute | Weber C.R.,University of Chicago | Wasland K.,NorthShore University Research Institute | Roy H.,NorthShore University Research Institute | And 3 more authors.
American Journal of Physiology - Gastrointestinal and Liver Physiology | Year: 2011

Epithelial proliferation, critical for homeostasis, healing, and colon cancer progression, is in part controlled by epidermal growth factor receptor (EGFR). Proliferation of colonic epithelia can be induced by Citrobacter rodentium infection, and we have demonstrated that activity of tumor suppressor FOXO3 was attenuated after this infection. Thus the aim of this study was to determine the contribution of FOXO3 in EGFR-dependent proliferation of intestinal epithelia and colon cancer cell lines. In this study we show that, during infection with C. rodentium, EGFR was significantly phosphorylated in colonic mucosa and Foxo3 deficiency in this model lead to an increased number of bromodeoxyuridine-positive cells. In vitro, in human colon cancer cells, increased expression and activation of EGFR was associated with proliferation that leads to FOXO3 phosphorylation (inactivation). Following EGFR activation, FOXO3 was phosphorylated (via phosphatidylinositol 3-kinase/Akt) and translocated to the cytosol where it was degraded. Moreover, inhibition of proliferation by overexpressing FOXO3 was not reversed by the EGFR signaling, implicating FOXO3 as one of the regulators downstream of EGFR. FOXO3 binding to the promoter of the cell cycle inhibitor p27kip1 was decreased by EGFR signaling, suggesting its role in EGFR-dependent proliferation. In conclusion, we show that proliferation in colonic epithelia and colon cancer cells, stimulated by EGFR, is mediated via loss of FOXO3 activity and speculate that FOXO3 may serve as a target in the development of new pharmacological treatments of proliferative diseases. Copyright © 2011 the American Physiological Society. Source

Qi W.,NorthShore University Research Institute | Joshi S.,University of Chicago | Weber C.R.,NorthShore University Research Institute | Wali R.K.,NorthShore University Research Institute | And 2 more authors.
Gut Microbes | Year: 2011

Infections from enteric bacteria such as enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic Escherichia coli (EHEC) are a public health threat worldwide. EPEC and EHEC are extracellular pathogens, and their interaction with host surface receptors is critical to the infection process. We previously demonstrated that polyethylene glycol (PE G) downregulates surface receptors in intestinal cells. Here we show that PE G decreases β1-integrin, the surface receptor in intestinal cells that is critical for EPEC and EHEC attachment. We hypothesized that PE G would inhibit the attachment of these enteric pathogens to host cells and improve clinical signs of infection. We found that attachment of the mouse enteric pathogen Citrobacter rodentium, which belongs to the same group of pathogens as EPEC and EHEC, was attenuated by the concurrent presence of PE G. Pretreatment with PE G, without concurrent presence during infection, also reduced bacterial attachment. This finding was further supported in vivo such as that PE G administered by gavage daily during infection as well as prior to infection significantly decreased C. rodentium in the colon and improved the appearance of the infected colon in mice. In addition, PE G decreased the β1-integrin in colonic mucosa and reduced the C. rodentium-induced activation of epidermal growth factor receptors. PE G also significantly reduced infectioninduced colonic inflammation. Finally, PE G efficiently reduced C. rodentium shedding from the colon during infection. In conclusion, PE G can be an efficient and safe preventive agent against EPEC and EHEC infections. © 2011 Landes Bioscience. Source

Qi W.,NorthShore University Research Institute | Weber C.R.,University of Chicago | Wasland K.,NorthShore University Research Institute | Savkovic S.D.,NorthShore University Research Institute
BMC Cancer | Year: 2011

Background: Soy consumption is associated with a lower incidence of colon cancer which is believed to be mediated by one of its of components, genistein. Genistein may inhibit cancer progression by inducing apoptosis or inhibiting proliferation, but mechanisms are not well understood. Epidermal growth factor (EGF)-induced proliferation of colon cancer cells plays an important role in colon cancer progression and is mediated by loss of tumor suppressor FOXO3 activity. The aim of this study was to assess if genistein exerts anti-proliferative properties by attenuating the negative effect of EGF on FOXO3 activity.Methods: The effect of genistein on proliferation stimulated by EGF-mediated loss of FOXO3 was examined in human colonic cancer HT-29 cells. EGF-induced FOXO3 phosphorylation and translocation were assessed in the presence of genistein. EGF-mediated loss of FOXO3 interactions with p53 (co-immunoprecipitation) and promoter of p27kip1 (ChIP assay) were examined in presence of genistein in cells with mutated p53 (HT-29) and wild type p53 (HCT116). Silencing of p53 determined activity of FOXO3 when it is bound to p53.Results: Genistein inhibited EGF-induced proliferation, while favoring dephosphorylation and nuclear retention of FOXO3 (active state) in colon cancer cells. Upstream of FOXO3, genistein acts via the PI3K/Akt pathway to inhibit EGF-stimulated FOXO3 phosphorylation (i.e. favors active state). Downstream, EGF-induced disassociation of FOXO3 from mutated tumor suppressor p53, but not wild type p53, is inhibited by genistein favoring FOXO3-p53(mut) interactions with the promoter of the cell cycle inhibitor p27kip1 in colon cancer cells. Thus, the FOXO3-p53(mut) complex leads to elevated p27kip1 expression and promotes cell cycle arrest.Conclusion: These novel anti-proliferative mechanisms of genistein suggest a possible role of combining genistein with other chemoreceptive agents for the treatment of colon cancer. © 2011 Qi et al; licensee BioMed Central Ltd. Source

Grippo P.,Northwestern University | Fitchev P.S.,NorthShore University Research Institute | Bentrem D.J.,Northwestern University | Melstrom L.G.,Northwestern University | And 11 more authors.
Gut | Year: 2012

Background and aims: Pigment epithelium-derived factor (PEDF), a non-inhibitory SERPIN with potent antiangiogenic activity, has been recently implicated in metabolism and adipogenesis, both of which are known to influence pancreatic cancer progression. Increased pancreatic fat in human pancreatic tumour correlates with greater tumour dissemination while PEDF deficiency in mice promotes pancreatic hyperplasia and visceral obesity. Oncogenic Ras, the most common mutation in pancreatic ductal adenocarcinoma (PDAC), has similarly been shown to promote adipogenesis and premalignant lesions. Methods: In order to determine whether concurrent loss of PEDF is sufficient to promote adipogenesis and tumorigenesis in the pancreas, the authors ablated PEDF in an EL-KrasG12D mouse model of non-invasive cystic papillary neoplasms. Results: EL-KrasG12D/PEDF deficient mice developed invasive PDAC associated with enhanced matrix metalloproteinase (MMP)-2 and MMP-9 expression and increased peripancreatic fat with adipocyte hypertrophy and intrapancreatic adipocyte infiltration (pancreatic steatosis). In support of increased adipogenesis, the stroma of the pancreas of EL-KrasG12D/PEDF deficient mice demonstrated higher tissue levels of two lipid droplet associated proteins, tail-interacting protein 47 (TIP47, perilipin 3) and adipose differentiation-related protein (ADRP, Pperilipin 2), while adipose triglyceride lipase, a key factor in lipolysis, was decreased. In patients with PDAC, both tissue and serum levels of PEDF were decreased, stromal TIP47 expression was higher and the tissue VEGF to PEDF ratio was increased (p<0.05). Conclusions: These data highlight the importance of lipid metabolism in the tumour microenvironment and identify PEDF as a critical negative regulator of both adiposity and tumour invasion in the pancreas. Source

Discover hidden collaborations