Publications by authors named "Md Jashim Uddin"

54 Publications

The IL-33-ILC2 pathway protects from amebic colitis.

Mucosal Immunol 2021 Aug 16. Epub 2021 Aug 16.

Department of Medicine: Infectious Diseases and International Health, University of Virginia School of Medicine, Charlottesville, VA, USA.

Entamoeba histolytica is a pathogenic protozoan parasite that causes intestinal colitis, diarrhea, and in some cases, liver abscess. Through transcriptomics analysis, we observed that E. histolytica infection was associated with increased expression of IL-33 mRNA in both the human and murine colon. IL-33, the IL-1 family cytokine, is released after cell injury to alert the immune system of tissue damage. Treatment with recombinant IL-33 protected mice from amebic infection and intestinal tissue damage; moreover, blocking IL-33 signaling made mice more susceptible to amebiasis. IL-33 limited the recruitment of inflammatory immune cells and decreased the pro-inflammatory cytokine IL-6 in the cecum. Type 2 immune responses were upregulated by IL-33 treatment during amebic infection. Interestingly, administration of IL-33 protected RAG2 mice but not RAG2γc mice, demonstrating that IL-33-mediated protection required the presence of innate lymphoid cells (ILCs). IL-33 induced recruitment of ILC2 but not ILC1 and ILC3 in RAG2 mice. At baseline and after amebic infection, there was a significantly higher IL13+ILC2s in C57BL/J mice, which are naturally resistant to amebiasis, than CBA/J mice. Adoptive transfer of ILC2s to RAG2γc mice restored IL-33-mediated protection. These data reveal that the IL-33-ILC2 pathway is an important host defense mechanism against amebic colitis.
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http://dx.doi.org/10.1038/s41385-021-00442-2DOI Listing
August 2021

Targeting diacylglycerol lipase reduces alcohol consumption in preclinical models.

J Clin Invest 2021 Jul 22. Epub 2021 Jul 22.

Department of Psychiatry and Behavioral Sciences, Vanderbilt University School of Medicine, Nashville, United States of America.

Alcohol use disorder (AUD) is associated with substantial morbidity, mortality, and societal cost, and pharmacological treatment options for AUD are limited. The endogenous cannabinoid (eCB) signaling system is critically involved in reward processing and alcohol intake is positively correlated with release of the eCB ligand 2-Arachidonoylglycerol (2-AG) within reward neurocircuitry. Here we show that genetic and pharmacological inhibition of diacylglycerol lipase (DAGL), the rate limiting enzyme in the synthesis of 2-AG, reduces alcohol consumption in a variety of preclinical models ranging from a voluntary free-access model to aversion resistant-drinking and dependence-like drinking induced via chronic intermittent ethanol vapor exposure in mice. DAGL inhibition during either chronic alcohol consumption or protracted withdrawal was devoid of anxiogenic and depressive-like behavioral effects. Lastly, DAGL inhibition also prevented ethanol-induced suppression of GABAergic transmission onto midbrain dopamine neurons, providing mechanistic insight into how DAGL inhibition could affect alcohol reward. These data suggest reducing 2-AG signaling via inhibition of DAGL could represent an effective approach to reduce alcohol consumption across the spectrum of AUD severity.
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http://dx.doi.org/10.1172/JCI146861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8409586PMC
July 2021

Optimizing a Multi-Component Intranasal Vaccine Formulation Using a Design of Experiments Strategy.

Front Immunol 2021 25;12:683157. Epub 2021 Jun 25.

Infectious Disease Research Institute (IDRI), Seattle, WA, United States.

Amebiasis is a neglected tropical disease caused by a. Although the disease burden varies geographically, amebiasis is estimated to account for some 55,000 deaths and millions of infections globally per year. Children and travelers are among the groups with the greatest risk of infection. There are currently no licensed vaccines for prevention of amebiasis, although key immune correlates for protection have been proposed from observational studies in humans. We previously described the development of a liposomal adjuvant formulation containing two synthetic TLR ligands (GLA and 3M-052) that enhanced antigen-specific fecal IgA, serum IgG2a, a mixed IFNγ and IL-17A cytokine profile from splenocytes, and protective efficacy following intranasal administration with the LecA antigen. By applying a statistical design of experiments (DOE) and desirability function approach, we now describe the optimization of the dose of each vaccine formulation component (LecA, GLA, 3M-052, and liposome) as well as the excipient composition (acyl chain length and saturation; PEGylated lipid:phospholipid ratio; and presence of antioxidant, tonicity, or viscosity agents) to maximize desired immunogenicity characteristics while maintaining physicochemical stability. This DOE/desirability index approach led to the identification of a lead candidate composition that demonstrated immune response durability and protective efficacy in the mouse model, as well as an assessment of the impact of each active vaccine formulation component on protection. Thus, we demonstrate that both GLA and 3M-052 are required for statistically significant protective efficacy. We also show that immunogenicity and efficacy results differ in female male mice, and the differences appear to be at least partly associated with adjuvant formulation composition.
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http://dx.doi.org/10.3389/fimmu.2021.683157DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8268010PMC
June 2021

Megasphaera in the Stool Microbiota Is Negatively Associated With Diarrheal Cryptosporidiosis.

Clin Infect Dis 2021 09;73(6):e1242-e1251

Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA.

Background: The protozoan parasites in the Cryptosporidium genus cause both acute diarrheal disease and subclinical (ie, nondiarrheal) disease. It is unclear if the microbiota can influence the manifestation of diarrhea during a Cryptosporidium infection.

Methods: To characterize the role of the gut microbiota in diarrheal cryptosporidiosis, the microbiome composition of both diarrheal and surveillance Cryptosporidium-positive fecal samples from 72 infants was evaluated using 16S ribosomal RNA gene sequencing. Additionally, the microbiome composition prior to infection was examined to test whether a preexisting microbiome profile could influence the Cryptosporidium infection phenotype.

Results: Fecal microbiome composition was associated with diarrheal symptoms at 2 timepoints. Megasphaera was significantly less abundant in diarrheal samples compared with subclinical samples at the time of Cryptosporidium detection (log2 [fold change] = -4.3; P = 10-10) and prior to infection (log2 [fold change] = -2.0; P = 10-4); this assigned sequence variant was detected in 8 children who had diarrhea and 30 children without diarrhea. Random forest classification also identified Megasphaera abundance in the pre- and postexposure microbiota as predictive of a subclinical infection.

Conclusions: Microbiome composition broadly, and specifically low Megasphaera abundance, was associated with diarrheal symptoms prior to and at the time of Cryptosporidium detection. This observation suggests that the gut microenvironment may play a role in determining the severity of a Cryptosporidium infection. Clinical Trials Registration. NCT02764918.
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http://dx.doi.org/10.1093/cid/ciab207DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8442784PMC
September 2021

Host Protective Mechanisms to Intestinal Amebiasis.

Trends Parasitol 2021 02 23;37(2):165-175. Epub 2020 Oct 23.

Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, VA, USA. Electronic address:

The protozoan parasite Entamoeba histolytica is the causative agent of amebiasis, an infection that manifests as colitis and, in some cases, liver abscess. A better understanding of host protective factors is key to developing an effective remedy. Recently, significant advances have been made in understanding the mechanisms of MUC2 production by goblet cells upon amebic infection, regulation of antimicrobial peptide production by Paneth cells, the interaction of commensal microbiota with immune stimulation, and host genetics in conferring protection from amebiasis. In addition to host pathways that may serve as potential therapeutic targets, significant progress has also been made with respect to development of a vaccine against amebiasis. Here, we aim to highlight the current understanding and knowledge gaps critically.
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http://dx.doi.org/10.1016/j.pt.2020.09.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7840892PMC
February 2021

Harmaline Analogs as Substrate-Selective Cyclooxygenase-2 Inhibitors.

ACS Med Chem Lett 2020 Oct 14;11(10):1881-1885. Epub 2020 Feb 14.

A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.

We report the design, synthesis, and evaluation of a series of harmaline analogs as selective inhibitors of 2-arachidonylglycerol (2-AG) oxygenation over arachidonic acid (AA) oxygenation by purified cyclooxygenase-2 (COX-2). A fused tricyclic harmaline analog containing a CHO substituent at C-6 and a CH group at the C-1 position of 4,9-dihydro-3-pyrido[3,4-]indole (compound ) was the best substrate-selective COX-2 inhibitor of those evaluated, exhibiting a 2AG-selective COX-2 inhibitory IC of 0.022 μM as compared to >1 μM for AA. The 2.66 Å resolution crystal complex of COX-2 with compound revealed that this series of tricyclic indoles binds in the cyclooxygenase channel by flipping the side chain of L531 toward the dimer interface. This novel tricyclic indole series provides the foundation for the development of promising substrate-selective molecules capable of increasing endocannabinoid (EC) levels in the brain to offer new treatments for a variety of diseases, from pain and inflammation to stress and anxiety disorders.
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http://dx.doi.org/10.1021/acsmedchemlett.9b00555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549255PMC
October 2020

Molecular Imaging of Inflammation in Osteoarthritis Using a Water-Soluble Fluorocoxib.

ACS Med Chem Lett 2020 Oct 24;11(10):1875-1880. Epub 2020 Feb 24.

A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.

Clinical imaging approaches to detect inflammatory biomarkers, such as cyclooxygenase-2 (COX-2), may facilitate the diagnosis and therapy of inflammatory diseases. To this end, we report the discovery of -[(rhodamin-X-yl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1-indol-3-yl]acetamide chloride salt (fluorocoxib D), a hydrophilic analog of fluorocoxib A. Fluorocoxib D inhibits COX-2 selectively in purified enzyme preparations and cells. It exhibits adequate photophysical properties to enable detection of COX-2 in intact cells, in a mouse model of carrageenan-induced acute footpad inflammation and inflammation in a mouse model of osteoarthritis. COX-2-selectivity was verified either by blocking the enzyme's active site with celecoxib or by molecular imaging with nontargeted 5-carboxy-X-rhodamine dye. These data indicate that fluorocoxib D is an ideal candidate for early detection of inflammatory or neoplastic lesions expressing elevated levels of COX-2.
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http://dx.doi.org/10.1021/acsmedchemlett.9b00512DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549260PMC
October 2020

Pharmacokinetic characterization of fluorocoxib D, a cyclooxygenase-2-targeted optical imaging agent for detection of cancer.

J Biomed Opt 2020 08;25(8)

Vanderbilt University School of Medicine, Vanderbilt Institute of Chemical Biology, Center for Molec, United States.

Significance: Fluorocoxib D, N-[(rhodamin-X-yl)but-4-yl]-2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetamide, is a water-soluble optical imaging agent to detect cyclooxygenase-2 (COX-2)-expressing cancer cells.

Aim: We evaluated the pharmacokinetic and safety properties of fluorocoxib D and its ability to detect cancer cells in vitro and in vivo.

Approach: Pharmacokinetic parameters of fluorocoxib D were assessed from plasma collected at designated time points after intravenous administration of 1  mg  /  kg fluorocoxib D in six research dogs using a high-performance liquid chromatography analysis. Safety of fluorocoxib D was assessed for 3 days after its administration using physical assessment, complete blood count, serum chemistry profile, and complete urinalysis in six research dogs. The ability of fluorocoxib D to detect COX-2-expressing cancer cells was performed using human 5637 cells in vitro and during rhinoscopy evaluation of specific fluorocoxib D uptake by canine cancer cells in vivo.

Results: No evidence of toxicity and no clinically relevant adverse events were noted in dogs. Peak concentration of fluorocoxib D (114.8  ±  50.5  ng  /  ml) was detected in plasma collected at 0.5 h after its administration. Pretreatment of celecoxib blocked specific uptake of fluorocoxib D in COX-2-expressing human 5637 cancer cells. Fluorocoxib D uptake was detected in histology-confirmed COX-2-expressing head and neck cancer during rhinoscopy in a client-owned dog in vivo. Specific tumor-to-normal tissue ratio of detected fluorocoxib D signal was in an average of 3.7  ±  0.9 using Image J analysis.

Conclusions: Our results suggest that fluorocoxib D is a safe optical imaging agent used for detection of COX-2-expressing cancers and their margins during image-guided minimally invasive biopsy and surgical procedures.
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http://dx.doi.org/10.1117/1.JBO.25.8.086005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7456637PMC
August 2020

Detection of carcinogen-induced bladder cancer by fluorocoxib A.

BMC Cancer 2019 Nov 27;19(1):1152. Epub 2019 Nov 27.

Department of Small Animal Clinical Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, TN, 37996, USA.

Background: Conventional cystoscopy can detect advanced stages of bladder cancer; however, it has limitations to detect bladder cancer at the early stages. Fluorocoxib A, a rhodamine-conjugated analog of indomethacin, is a novel fluorescent imaging agent that selectively targets cyclooxygenase-2 (COX-2)-expressing cancers.

Methods: In this study, we have used a carcinogen N-butyl-N-4-hydroxybutyl nitrosamine (BBN)-induced bladder cancer immunocompetent mouse B6D2F1 model that resembles human high-grade invasive urothelial carcinoma. We evaluated the ability of fluorocoxib A to detect the progression of carcinogen-induced bladder cancer in mice. Fluorocoxib A uptake by bladder tumors was detected ex vivo using IVIS optical imaging system and Cox-2 expression was confirmed by immunohistochemistry and western blotting analysis. After ex vivo imaging, the progression of bladder carcinogenesis from normal urothelium to hyperplasia, carcinoma-in-situ and carcinoma with increased Ki67 and decreased uroplakin-1A expression was confirmed by histology and immunohistochemistry analysis.

Results: The specific uptake of fluorocoxib A correlated with increased Cox-2 expression in progressing bladder cancer. In conclusion, fluorocoxib A detected the progression of bladder carcinogenesis in a mouse model with selective uptake in Cox-2-expressing bladder hyperplasia, CIS and carcinoma by 4- and 8-fold, respectively, as compared to normal bladder urothelium, where no fluorocoxib A was detected.

Conclusions: Fluorocoxib A is a targeted optical imaging agent that could be applied for the detection of Cox-2 expressing human bladder cancer.
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http://dx.doi.org/10.1186/s12885-019-6366-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6882158PMC
November 2019

Targeted Detection of Cyclooxygenase-1 in Ovarian Cancer.

ACS Med Chem Lett 2020 Oct 24;11(10):1837-1842. Epub 2019 Jul 24.

A. B. Hancock, Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232 United States.

Overexpression of cyclooxygenase-1 (COX-1) is associated with the initiation and progression of ovarian cancer, and targeted imaging of COX-1 is a promising strategy for early detection of this disease. We report the discovery of -[(5-carboxy-X-rhodaminyl)but-4-yl]-3-(1-(4-methoxyphenyl)-5-(-tolyl)-1-pyrazol-3-yl)propenamide (CMP) as the first COX-1-targeted optical agent for imaging of ovarian cancer. CMP exhibits light emission at 604 nm (λ), thereby minimizing tissue autofluorescence interference. In both purified enzyme and COX-1-expressing human ovarian adenocarcinoma (OVCAR-3) cells, CMP inhibits COX-1 at low nanomolar potencies (IC = 94 and 44 nM, respectively). CMP's selective binding to COX-1 in OVCAR-3 cells was visualized microscopically as intense intracellular fluorescence. optical imaging of xenografts in athymic nude mice revealed COX-1-dependent accumulation of CMP in COX-1-expressing mouse ovarian surface epithelial carcinoma (ID8-NGL) and OVCAR-3 cells. These results establish proof-of-principle for the feasibility of targeting COX-1 in the development of new imaging and therapeutic strategies for ovarian cancer.
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http://dx.doi.org/10.1021/acsmedchemlett.9b00280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7549111PMC
October 2020

Discovery of Furanone-Based Radiopharmaceuticals for Diagnostic Targeting of COX-1 in Ovarian Cancer.

ACS Omega 2019 May 24;4(5):9251-9261. Epub 2019 May 24.

A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Department of Biochemistry, Chemistry and Pharmacology, Vanderbilt Institute of Chemical Biology, Vanderbilt-Ingram Cancer Center, and Department of Radiology and Radiological Sciences, Vanderbilt Institute of Imaging Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States.

In vivo targeting and visualization of cyclooxygenase-1 (COX-1) using multimodal positron emission tomography/computed tomography imaging represents a unique opportunity for early detection and/or therapeutic evaluation of ovarian cancer because overexpression of COX-1 has been characterized as a pathologic hallmark of the initiation and progression of this disease. The furanone core is a common building block of many synthetic and natural products that exhibit a wide range of biological activities. We hypothesize that furanone-based COX-1 inhibitors can be designed as imaging agents for the early detection, delineation of tumor margin, and evaluation of treatment response of ovarian cancer. We report the discovery of 3-(4-fluorophenyl)-5,5-dimethyl-4-(-tolyl)furan-2(5)-one (FDF), a furanone-based novel COX-1-selective inhibitor that exhibits adequate in vivo stability, plasma half-life, and pharmacokinetic properties for use as an imaging agent. We describe a novel synthetic scheme in which a Lewis acid-catalyzed nucleophilic aromatic deiodo[F]fluorination reaction is utilized for the radiosynthesis of [F]FDF. [F]FDF binds efficiently to COX-1 in vivo and enables sensitive detection of ovarian cancer in subcutaneous and peritoneal xenograft models in mice. These results provide the proof of principle for COX-1-targeted imaging of ovarian cancer and identify [F]FDF as a promising lead compound for further preclinical and clinical development.
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http://dx.doi.org/10.1021/acsomega.9b01093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6545551PMC
May 2019

Fluorescent indomethacin-dansyl conjugates utilize the membrane-binding domain of cyclooxygenase-2 to block the opening to the active site.

J Biol Chem 2019 05 18;294(22):8690-8698. Epub 2019 Apr 18.

From the A. B. Hancock Jr. Memorial Laboratory for Cancer Research, Departments of Biochemistry, Chemistry, and Pharmacology, Vanderbilt Institute of Chemical Biology, Center in Molecular Toxicology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232,

Many indomethacin amides and esters are cyclooxygenase-2 (COX-2)-selective inhibitors, providing a framework for the design of COX-2-targeted imaging and cancer chemotherapeutic agents. Although previous studies have suggested that the amide or ester moiety of these inhibitors binds in the lobby region, a spacious alcove within the enzyme's membrane-binding domain, structural details have been lacking. Here, we present observations on the crystal complexes of COX-2 with two indomethacin-dansyl conjugates (compounds 1 and 2) at 2.22-Å resolution. Both compounds are COX-2-selective inhibitors with IC values of 0.76 and 0.17 μm, respectively. Our results confirmed that the dansyl moiety is localized in and establishes hydrophobic interactions and several hydrogen bonds with the lobby of the membrane-binding domain. We noted that in both crystal structures, the linker tethering indomethacin to the dansyl moiety passes through the constriction at the mouth of the COX-2 active site, resulting in displacement and disorder of Arg-120, located at the opening to the active site. Both compounds exhibited higher inhibitory potency against a COX-2 R120A variant than against the WT enzyme. Inhibition kinetics of compound 2 were similar to those of the indomethacin parent compound against WT COX-2, and the R120A substitution reduced the time dependence of COX inhibition. These results provide a structural basis for the further design and optimization of conjugated COX reagents for imaging of malignant or inflammatory tissues containing high COX-2 levels.
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http://dx.doi.org/10.1074/jbc.RA119.007405DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6552414PMC
May 2019

Identification of Etiology-Specific Diarrhea Associated With Linear Growth Faltering in Bangladeshi Infants.

Am J Epidemiol 2018 10;187(10):2210-2218

Division of Infectious Diseases and International Health, School of Medicine, University of Virginia, Charlottesville, Virginia.

Childhood diarrhea in low-resource settings has been variably linked to linear growth shortfalls. However, the association between etiology-specific diarrhea and growth has not been comprehensively evaluated. We tested diarrheal stools collected from the Performance of Rotavirus and Oral Polio Vaccines in Developing Countries study from 2011 to 2013 in Dhaka, Bangladesh, by quantitative polymerase chain reaction for a broad range of enteropathogens to characterize diarrhea etiology and examine the association between etiology-specific diarrhea and linear growth and systemic inflammation. Pathogen-specific burdens of diarrhea were determined using attributable fractions. Linear regression was used to examine associations of pathogen-specific diarrhea with length-for-age z scores (LAZ) and serum C-reactive protein. There was no relationship between all-cause diarrhea and length at 12 months (change in 12-month LAZ per episode, -0.01, 95% confidence interval (CI): -0.06, 0.03). However, Cryptosporidium (change in 12-month LAZ per attributable episode, -0.23, 95% CI: -0.50, 0.03), Campylobacter jejuni/coli (change of -0.16, 95% CI: -0.32, -0.01), and Shigella/enteroinvasive Escherichia coli diarrhea (change of -0.12, 95% CI: -0.26, 0.03) were associated with linear growth deficits. Diarrhea attributable to C. jejuni/coli and Shigella/enteroinvasive E. coli were associated with elevated C-reactive protein. The association between diarrhea and linear growth appears to be pathogen-specific, reinforcing the need for pathogen-specific interventions.
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http://dx.doi.org/10.1093/aje/kwy106DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6166216PMC
October 2018

Microbiome-mediated neutrophil recruitment via CXCR2 and protection from amebic colitis.

PLoS Pathog 2017 Aug 17;13(8):e1006513. Epub 2017 Aug 17.

Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, United States of America.

The disease severity of Entamoeba histolytica infection ranges from asymptomatic to life-threatening. Recent human and animal data implicate the gut microbiome as a modifier of E. histolytica virulence. Here we have explored the association of the microbiome with susceptibility to amebiasis in infants and in the mouse model of amebic colitis. Dysbiosis occurred symptomatic E. histolytica infection in children, as evidenced by a lower Shannon diversity index of the gut microbiota. To test if dysbiosis was a cause of susceptibility, wild type C57BL/6 mice (which are innately resistant to E. histiolytica infection) were treated with antibiotics prior to cecal challenge with E. histolytica. Compared with untreated mice, antibiotic pre-treated mice had more severe colitis and delayed clearance of E. histolytica. Gut IL-25 and mucus protein Muc2, both shown to provide innate immunity in the mouse model of amebic colitis, were lower in antibiotic pre-treated mice. Moreover, dysbiotic mice had fewer cecal neutrophils and myeloperoxidase activity. Paradoxically, the neutrophil chemoattractant chemokines CXCL1 and CXCL2, as well as IL-1β, were higher in the colon of mice with antibiotic-induced dysbiosis. Neutrophils from antibiotic pre-treated mice had diminished surface expression of the chemokine receptor CXCR2, potentially explaining their inability to migrate to the site of infection. Blockade of CXCR2 increased susceptibility of control non-antibiotic treated mice to amebiasis. In conclusion, dysbiosis increased the severity of amebic colitis due to decreased neutrophil recruitment to the gut, which was due in part to decreased surface expression on neutrophils of CXCR2.
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http://dx.doi.org/10.1371/journal.ppat.1006513DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5560520PMC
August 2017

Community transmission of type 2 poliovirus after cessation of trivalent oral polio vaccine in Bangladesh: an open-label cluster-randomised trial and modelling study.

Lancet Infect Dis 2017 10 7;17(10):1069-1079. Epub 2017 Jul 7.

Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, VA, USA.

Background: Trivalent oral polio vaccine (tOPV) was replaced worldwide from April, 2016, by bivalent types 1 and 3 oral polio vaccine (bOPV) and one dose of inactivated polio vaccine (IPV) where available. The risk of transmission of type 2 poliovirus or Sabin 2 virus on re-introduction or resurgence of type 2 poliovirus after this switch is not understood completely. We aimed to assess the risk of Sabin 2 transmission after a polio vaccination campaign with a monovalent type 2 oral polio vaccine (mOPV2).

Methods: We did an open-label cluster-randomised trial in villages in the Matlab region of Bangladesh. We randomly allocated villages (clusters) to either: tOPV at age 6 weeks, 10 weeks, and 14 weeks; or bOPV at age 6 weeks, 10 weeks, and 14 weeks and either one dose of IPV at age 14 weeks or two doses of IPV at age 14 weeks and 18 weeks. After completion of enrolment, we implemented an mOPV2 vaccination campaign that targeted 40% of children younger than 5 years, regardless of enrolment status. The primary outcome was Sabin 2 incidence in the 10 weeks after the campaign in per-protocol infants who did not receive mOPV2, as assessed by faecal shedding of Sabin 2 by reverse transcriptase quantitative PCR (RT-qPCR). The effect of previous immunity on incidence was also investigated with a dynamical model of poliovirus transmission to observe prevalence and incidence of Sabin 2 virus. This trial is registered at ClinicalTrials.gov, number NCT02477046.

Findings: Between April 30, 2015, and Jan 14, 2016, individuals from 67 villages were enrolled to the study. 22 villages (300 infants) were randomly assigned tOPV, 23 villages (310 infants) were allocated bOPV and one dose of IPV, and 22 villages (329 infants) were assigned bOPV and two doses of IPV. Faecal shedding of Sabin 2 in infants who did not receive the mOPV2 challenge did not differ between children immunised with bOPV and one or two doses of IPV and those who received tOPV (15 of 252 [6%] vs six of 122 [4%]; odds ratio [OR] 1·29, 95% CI 0·45-3·72; p=0·310). However, faecal shedding of Sabin 2 in household contacts was increased significantly with bOPV and one or two doses of IPV compared with tOPV (17 of 751 [2%] vs three of 353 [1%]; OR 3·60, 95% CI 0·82-15·9; p=0·045). Dynamical modelling of within-household incidence showed that immunity in household contacts limited transmission.

Interpretation: In this study, simulating 1 year of tOPV cessation, Sabin 2 transmission was higher in household contacts of mOPV2 recipients in villages receiving bOPV and either one or two doses of IPV, but transmission was not increased in the community as a whole as shown by the non-significant difference in incidence among infants. Dynamical modelling indicates that transmission risk will be higher with more time since cessation.

Funding: Bill & Melinda Gates Foundation.
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http://dx.doi.org/10.1016/S1473-3099(17)30358-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5610141PMC
October 2017

Functional Redundancy Between Canonical Endocannabinoid Signaling Systems in the Modulation of Anxiety.

Biol Psychiatry 2017 Oct 15;82(7):488-499. Epub 2017 Mar 15.

Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee. Electronic address:

Background: Increasing the available repertoire of effective treatments for mood and anxiety disorders represents a critical unmet need. Pharmacological augmentation of endogenous cannabinoid (eCB) signaling has been suggested to represent a novel approach to the treatment of anxiety disorders; however, the functional interactions between two canonical eCB pathways mediated via anandamide (N-arachidonylethanolamine [AEA]) and 2-arachidonoylglycerol (2-AG) in the regulation of anxiety are not well understood.

Methods: We utilized pharmacological augmentation and depletion combined with behavioral and electrophysiological approaches to probe the role of 2-AG signaling in the modulation of stress-induced anxiety and the functional redundancy between AEA and 2-AG signaling in the modulation of anxiety-like behaviors in mice.

Results: Selective 2-AG augmentation reduced anxiety in the light/dark box assay and prevented stress-induced increases in anxiety associated with limbic AEA deficiency. In contrast, acute 2-AG depletion increased anxiety-like behaviors, which was normalized by selective pharmacological augmentation of AEA signaling and via direct cannabinoid receptor 1 stimulation with Δ-tetrahydrocannabinol. Electrophysiological studies revealed 2-AG modulation of amygdala glutamatergic transmission as a key synaptic correlate of the anxiolytic effects of 2-AG augmentation.

Conclusions: Although AEA and 2-AG likely subserve distinct physiological roles, a pharmacological and functional redundancy between these canonical eCB signaling pathways exists in the modulation of anxiety-like behaviors. These data support development of eCB-based treatment approaches for mood and anxiety disorders and suggest a potentially wider therapeutic overlap between AEA and 2-AG augmentation approaches than was previously appreciated.
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http://dx.doi.org/10.1016/j.biopsych.2017.03.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5585044PMC
October 2017

Association between enteropathogens and malnutrition in children aged 6-23 mo in Bangladesh: a case-control study.

Am J Clin Nutr 2017 05 5;105(5):1132-1138. Epub 2017 Apr 5.

International Center for Diarrhoeal Disease Research, Bangladesh, Dhaka, Bangladesh.

Early exposure to enteropathogens has been associated with malnutrition in children in low-resource settings. However, the contribution of individual enteropathogens remains poorly defined. Molecular diagnostics offer an increase in sensitivity for detecting enteropathogens but have not been comprehensively applied to studies of malnutrition. We sought to identify enteropathogens associated with malnutrition in Bangladesh. Malnourished children [weight-for-age score (WAZ) <-2] aged 6-23 mo in Dhaka, Bangladesh, and identified by active community surveillance were enrolled as cases, and normal-weight children (WAZ >-1) of the same age and from the same community were enrolled as controls. Stools were collected at enrollment and, for cases, after a 5-mo nutritional intervention. Enrollment and follow-up stools were tested by quantitative polymerase chain reaction for 32 enteropathogens with the use of a custom-developed TaqMan Array Card. Enteropathogen testing was performed on 486 cases and 442 controls upon enrollment and 365 cases at follow-up. At enrollment, the detection of enteroaggregative (OR: 1.39; 95% CI: 1.05, 1.83), spp. (OR: 1.46; 95% CI: 1.11, 1.91), heat-labile enterotoxin-producing (OR: 1.55; 95% CI: 1.04, 2.33), /enteroinvasive (OR: 1.65; 95% CI: 1.10, 2.46), norovirus genogroup I (OR: 1.66; 95% CI: 1.23, 2.25), and (OR: 1.73; 95% CI: 1.20, 2.49) were associated with malnourished cases, and the total burden of these pathogens remained associated with malnutrition after adjusting for sociodemographic factors. The number of these pathogens at follow-up was negatively associated with the change in WAZ during the intervention (-0.10 change in WAZ per pathogen detected; 95% CI: -0.14, -0.06), whereas the number at enrollment was positively associated with the change in WAZ (0.05 change in WAZ per pathogen detected; 95% CI: 0.00, 0.10). A subset of enteropathogens was associated with malnutrition in this setting. Broad interventions designed to reduce the burden of infection with these pathogens are needed. This trial was registered at clinicaltrials.gov as NCT02441426.
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http://dx.doi.org/10.3945/ajcn.116.138800DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5402031PMC
May 2017

Endocannabinoid signalling modulates susceptibility to traumatic stress exposure.

Nat Commun 2017 03 28;8:14782. Epub 2017 Mar 28.

Department of Psychiatry and Behavioral Sciences, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA.

Stress is a ubiquitous risk factor for the exacerbation and development of affective disorders including major depression and posttraumatic stress disorder. Understanding the neurobiological mechanisms conferring resilience to the adverse consequences of stress could have broad implications for the treatment and prevention of mood and anxiety disorders. We utilize laboratory mice and their innate inter-individual differences in stress-susceptibility to demonstrate a critical role for the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) in stress-resilience. Specifically, systemic 2-AG augmentation is associated with a stress-resilient phenotype and enhances resilience in previously susceptible mice, while systemic 2-AG depletion or CB1 receptor blockade increases susceptibility in previously resilient mice. Moreover, stress-resilience is associated with increased phasic 2-AG-mediated synaptic suppression at ventral hippocampal-amygdala glutamatergic synapses and amygdala-specific 2-AG depletion impairs successful adaptation to repeated stress. These data indicate amygdala 2-AG signalling mechanisms promote resilience to adverse effects of acute traumatic stress and facilitate adaptation to repeated stress exposure.
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http://dx.doi.org/10.1038/ncomms14782DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5379055PMC
March 2017

Fluorocoxib A enables targeted detection of cyclooxygenase-2 in laser-induced choroidal neovascularization.

J Biomed Opt 2016 09;21(9):90503

Vanderbilt University School of Medicine, Vanderbilt Eye Institute, Department of Ophthalmology and Visual Sciences, Nashville, Tennessee 37232-6840, United StatesdPharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd., Basel 4070, Switzerland.

Ocular angiogenesis is a blinding complication of age-related macular degeneration and other retinal vascular diseases. Clinical imaging approaches to detect inflammation prior to the onset of neovascularization in these diseases may enable early detection and timely therapeutic intervention. We demonstrate the feasibility of a previously developed cyclooxygenase-2 (COX-2) targeted molecular imaging probe, fluorocoxib A, for imaging retinal inflammation in a mouse model of laser-induced choroidal neovascularization. This imaging probe exhibited focal accumulation within laser-induced neovascular lesions, with minimal detection in proximal healthy tissue. The selectivity of the probe for COX-2 was validated
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http://dx.doi.org/10.1117/1.JBO.21.9.090503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5021825PMC
September 2016

Antitumor Activity of Cytotoxic Cyclooxygenase-2 Inhibitors.

ACS Chem Biol 2016 11 19;11(11):3052-3060. Epub 2016 Sep 19.

Departments of Biochemistry, Chemistry, and Pharmacology, A.B. Hancock Memorial Laboratory for Cancer Research, Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine , 850 RRB, 2220 Pierce Ave., Nashville, Tennessee 37232, United States.

Targeted delivery of chemotherapeutic agents to tumors has been explored as a means to increase the selectivity and potency of cytotoxicity. Most efforts in this area have exploited the molecular recognition of proteins highly expressed on the surface of cancer cells followed by internalization. A related approach that has received less attention is the targeting of intracellular proteins by ligands conjugated to anticancer drugs. An attractive target for this approach is the enzyme cyclooxygenase-2 (COX-2), which is highly expressed in a range of malignant tumors. Herein, we describe the synthesis and evaluation of a series of chemotherapeutic agents targeted to COX-2 by conjugation to indomethacin. Detailed characterization of compound 12, a conjugate of indomethacin with podophyllotoxin, revealed highly potent and selective COX-2 inhibition in vitro and in intact cells. Kinetics and X-ray crystallographic studies demonstrated that compound 12 is a slow, tight-binding inhibitor that likely binds to COX-2's allosteric site with its indomethacin moiety in a conformation similar to that of indomethacin. Compound 12 exhibited cytotoxicity in cell culture similar to that of podophyllotoxin with no evidence of COX-2-dependent selectivity. However, in vivo, compound 12 accumulated selectively in and more effectively inhibited the growth of a COX-2-expressing xenograft compared to a xenograft that did not express COX-2. Compound 12, which we have named chemocoxib A, provides proof-of-concept for the in vivo targeting of chemotherapeutic agents to COX-2 but suggests that COX-2-dependent selectivity may not be evident in cell culture-based assays.
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http://dx.doi.org/10.1021/acschembio.6b00560DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5289892PMC
November 2016

In Vivo Imaging of Retinal Hypoxia in a Model of Oxygen-Induced Retinopathy.

Sci Rep 2016 08 5;6:31011. Epub 2016 Aug 5.

Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA.

Ischemia-induced hypoxia elicits retinal neovascularization and is a major component of several blinding retinopathies such as retinopathy of prematurity (ROP), diabetic retinopathy (DR) and retinal vein occlusion (RVO). Currently, noninvasive imaging techniques capable of detecting and monitoring retinal hypoxia in living systems do not exist. Such techniques would greatly clarify the role of hypoxia in experimental and human retinal neovascular pathogenesis. In this study, we developed and characterized HYPOX-4, a fluorescence-imaging probe capable of detecting retinal-hypoxia in living animals. HYPOX-4 dependent in vivo and ex vivo imaging of hypoxia was tested in a mouse model of oxygen-induced retinopathy (OIR). Predicted patterns of retinal hypoxia were imaged by HYPOX-4 dependent fluorescence activity in this animal model. In retinal cells and mouse retinal tissue, pimonidazole-adduct immunostaining confirmed the hypoxia selectivity of HYPOX-4. HYPOX-4 had no effect on retinal cell proliferation as indicated by BrdU assay and exhibited no acute toxicity in retinal tissue as indicated by TUNEL assay and electroretinography (ERG) analysis. Therefore, HYPOX-4 could potentially serve as the basis for in vivo fluorescence-based hypoxia-imaging techniques, providing a tool for investigators to understand the pathogenesis of ischemic retinopathies and for physicians to address unmet clinical needs.
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http://dx.doi.org/10.1038/srep31011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4974503PMC
August 2016

Discovery of (R)-2-(6-Methoxynaphthalen-2-yl)butanoic Acid as a Potent and Selective Aldo-keto Reductase 1C3 Inhibitor.

J Med Chem 2016 08 12;59(16):7431-44. Epub 2016 Aug 12.

Department of Systems Pharmacology and Translational Therapeutics and the Center for Excellence in Environmental Toxicology, Perelman School of Medicine, University of Pennsylvania , 1315 BRBII/III, 421 Curie Boulevard, Philadelphia, Pennsylvania 19104-6160, United States.

Type 5 17β-hydroxysteroid dehydrogenase, aldo-keto reductase 1C3 (AKR1C3) converts Δ(4)-androstene-3,17-dione and 5α-androstane-3,17-dione to testosterone (T) and 5α-dihydrotestosterone, respectively, in castration resistant prostate cancer (CRPC). In CRPC, AKR1C3 is implicated in drug resistance, and enzalutamide drug resistance can be surmounted by indomethacin a potent inhibitor of AKR1C3. We examined a series of naproxen analogues and find that (R)-2-(6-methoxynaphthalen-2-yl)butanoic acid (in which the methyl group of R-naproxen was replaced by an ethyl group) acts as a potent AKR1C3 inhibitor that displays selectivity for AKR1C3 over other AKR1C enzymes. This compound was devoid of inhibitory activity on COX isozymes and blocked AKR1C3 mediated production of T and induction of PSA in LNCaP-AKR1C3 cells as a model of a CRPC cell line. R-Profens are substrate selective COX-2 inhibitors and block the oxygenation of endocannabinoids and in the context of advanced prostate cancer R-profens could inhibit intratumoral androgen synthesis and act as analgesics for metastatic disease.
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http://dx.doi.org/10.1021/acs.jmedchem.6b00160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5149398PMC
August 2016

Impact of enterovirus and other enteric pathogens on oral polio and rotavirus vaccine performance in Bangladeshi infants.

Vaccine 2016 06 3;34(27):3068-3075. Epub 2016 May 3.

Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville 22908, USA.

Background: Oral polio vaccine (OPV) and rotavirus vaccine (RV) exhibit poorer performance in low-income settings compared to high-income settings. Prior studies have suggested an inhibitory effect of concurrent non-polio enterovirus (NPEV) infection, but the impact of other enteric infections has not been comprehensively evaluated.

Methods: In urban Bangladesh, we tested stools for a broad range of enteric viruses, bacteria, parasites, and fungi by quantitative PCR from infants at weeks 6 and 10 of life, coincident with the first OPV and RV administration respectively, and examined the association between enteropathogen quantity and subsequent OPV serum neutralizing titers, serum rotavirus IgA, and rotavirus diarrhea.

Results: Campylobacter and enterovirus (EV) quantity at the time of administration of the first dose of OPV was associated with lower OPV1-2 serum neutralizing titers, while enterovirus quantity was also associated with diminished rotavirus IgA (-0.08 change in log titer per tenfold increase in quantity; P=0.037), failure to seroconvert (OR 0.78, 95% CI: 0.64-0.96; P=0.022), and breakthrough rotavirus diarrhea (OR 1.34, 95% CI: 1.05-1.71; P=0.020) after adjusting for potential confounders. These associations were not observed for Sabin strain poliovirus quantity.

Conclusion: In this broad survey of enteropathogens and oral vaccine performance we find a particular association between EV carriage, particularly NPEV, and OPV immunogenicity and RV protection. Strategies to reduce EV infections may improve oral vaccine responses. ClinicalTrials.gov Identifier: NCT01375647.
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http://dx.doi.org/10.1016/j.vaccine.2016.04.080DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4912219PMC
June 2016

Fluorocoxib A loaded nanoparticles enable targeted visualization of cyclooxygenase-2 in inflammation and cancer.

Biomaterials 2016 Jun 21;92:71-80. Epub 2016 Mar 21.

Department of Biomedical Engineering, Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University School of Engineering, Nashville, TN 37232, USA. Electronic address:

Cyclooxygenase-2 (COX-2) is expressed in virtually all solid tumors and its overexpression is a hallmark of inflammation. Thus, it is a potentially powerful biomarker for the early clinical detection of inflammatory disease and human cancers. We report a reactive oxygen species (ROS) responsive micellar nanoparticle, PPS-b-POEGA, that solubilizes the first fluorescent COX-2-selective inhibitor fluorocoxib A (FA) for COX-2 visualization in vivo. Pharmacokinetics and biodistribution of FA-PPS-b-POEGA nanoparticles (FA-NPs) were assessed after a fully-aqueous intravenous (i.v.) administration in wild-type mice and revealed 4-8 h post-injection as an optimal fluorescent imaging window. Carrageenan-induced inflammation in the rat and mouse footpads and 1483 HNSCC tumor xenografts were successfully visualized by FA-NPs with fluorescence up to 10-fold higher than that of normal tissues. The targeted binding of the FA cargo was blocked by pretreatment with the COX-2 inhibitor indomethacin, confirming COX-2-specific binding and local retention of FA at pathological sites. Our collective data indicate that FA-NPs are the first i.v.-ready FA formulation, provide high signal-to-noise in inflamed, premalignant, and malignant tissues, and will uniquely enable clinical translation of the poorly water-soluble FA compound.
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http://dx.doi.org/10.1016/j.biomaterials.2016.03.028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4833621PMC
June 2016

Aberrant over-expression of COX-1 intersects multiple pro-tumorigenic pathways in high-grade serous ovarian cancer.

Oncotarget 2015 Aug;6(25):21353-68

Department of Obstetrics & Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA.

Cyclooxygenase-1 (COX-1) is implicated in ovarian cancer. However, patterns of COX expression and function have been unclear and controversial. In this report, patterns of COX-1 and COX-2 gene expression were obtained from RNA-seq data through The Cancer Genome Atlas. Our analysis revealed markedly higher COX-1 mRNA expression than COX-2 in high-grade serous ovarian cancers (HGSOC) and higher COX-1 expression in HGSOC tumors than 10 other tumor types. High expression of COX-1 in HGSOC tumors was confirmed in an independent tissue microarray. In contrast, lower or similar expression of COX-1 compared to COX-2 was observed in endometrioid, mucinous and clear cell tumors. Stable COX-1 knockdown in HGSOC-representative OVCAR-3 ovarian cancer cells reduced gene expression in multiple pro-tumorigenic pathways. Functional cell viability, clonogenicity, and migration/invasion assays were consistent with transcriptomic changes. These effects were reversed by stable over-expression of COX-1 in SKOV-3 cells. Our results demonstrate a distinct pattern of COX-1 over-expression in HGSOC tumors and strong association of COX-1 with multiple pro-tumorigenic pathways in ovarian cancer cells. These findings provide additional insight into the role of COX-1 in human ovarian cancer and support further development of methods to selectively target COX-1 in the management of HGSOC tumors.
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http://dx.doi.org/10.18632/oncotarget.3860DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4673270PMC
August 2015

Targeted imaging of cancer by fluorocoxib C, a near-infrared cyclooxygenase-2 probe.

J Biomed Opt 2015 May;20(5):50502

Cyclooxygenase-2 (COX-2) is a promising target for the imaging of cancer in a range of diagnostic and therapeutic settings. We report a near-infrared COX-2-targeted probe, fluorocoxib C (FC), for visualization of solid tumors by optical imaging. FC exhibits selective and potent COX-2 inhibition in both purified protein and human cancercell lines. In vivo optical imaging shows selective accumulation of FC in COX-2-overexpressing human tumor xenografts [1483 head and neck squamous cell carcinoma (HNSCC)] implanted in nude mice, while minimal uptake is detectable in COX-2-negative tumor xenografts (HCT116)or 1483 HNSCC xenografts preblocked with the COX-2-selective inhibitor celecoxib. Time course imaging studies conducted from 3 h to 7-day post-FC injection revealed a marked reduction in nonspecific fluorescent signals with retention of fluorescence in 1483 HNSCC tumors. Thus, use of FC in a delayed imaging protocol offers an approach to improve imaging signal-to-noise that should improve cancer detection in multiple preclinical and clinical settings.
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http://dx.doi.org/10.1117/1.JBO.20.5.050502DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4430360PMC
May 2015

Applications of azo-based probes for imaging retinal hypoxia.

ACS Med Chem Lett 2015 Apr 12;6(4):445-9. Epub 2015 Feb 12.

Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center , Nashville, Tennessee 37232, United States ; Molecular Physiology and Biophysics, Vanderbilt University School of Medicine , Nashville, Tennessee 37232, United States.

We report the design and synthesis of an activatable molecular imaging probe to detect hypoxia in mouse models of retinal vascular diseases. Hypoxia of the retina has been associated with the initiation and progression of blinding retinal vascular diseases including age-related macular degeneration, diabetic retinopathy, and retinopathy of prematurity. In vivo retinal imaging of hypoxia may be useful for early detection and timely treatment of retinal diseases. To achieve this goal, we synthesized HYPOX-3, a near-infrared (NIR) imaging agent coupled to a dark quencher, Black Hole Quencher 3 (BHQ3), which has been previously reported to contain a hypoxia-sensitive cleavable azo-bond. HYPOX-3 was cleaved in hypoxic retinal cell culture and animal models, enabling detection of hypoxia with high signal-to-noise ratios without acute toxicity. HYPOX-3 fluorescences in hypoxic cells and tissues and was undetectable under normoxia. These imaging agents are promising candidates for imaging retinal hypoxia in preclinical disease models and patients.
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http://dx.doi.org/10.1021/ml5005206DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394343PMC
April 2015

Detection of non-melanoma skin cancer by in vivo fluorescence imaging with fluorocoxib A.

Neoplasia 2015 Feb;17(2):201-7

Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, CA; Dept. of Pediatrics, Stanford University School of Medicine, Stanford, CA; Dept. of Radiology, Stanford University School of Medicine, Stanford, CA; Dept. of Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA. Electronic address:

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the US and its incidence is increasing. The current standard of care is visual inspection by physicians and/or dermatologists, followed by skin biopsy and pathologic confirmation. We have investigated the use of in vivo fluorescence imaging using fluorocoxib A as a molecular probe for early detection and assessment of skin tumors in mouse models of NMSC. Fluorocoxib A targets the cyclooxygenase-2 (COX-2) enzyme that is preferentially expressed by inflamed and tumor tissue, and therefore has potential to be an effective broadly active molecular biomarker for cancer detection. We tested the sensitivity of fluorocoxib A in a BCC allograft SCID hairless mouse model using a wide-field fluorescence imaging system. Subcutaneous allografts comprised of 1000 BCC cells were detectable above background. These BCC allograft mice were imaged over time and a linear correlation (R(2) = 0.8) between tumor volume and fluorocoxib A signal levels was observed. We also tested fluorocoxib A in a genetically engineered spontaneous BCC mouse model (Ptch1(+/-) K14-Cre-ER2 p53(fl/fl)), where sequential imaging of the same animals over time demonstrated that early, microscopic lesions (100 μm size) developed into visible macroscopic tumor masses over 11 to 17 days. Overall, for macroscopic tumors, the sensitivity was 88% and the specificity was 100%. For microscopic tumors, the sensitivity was 85% and specificity was 56%. These results demonstrate the potential of fluorocoxib A as an in vivo imaging agent for early detection, margin delineation and guided biopsies of NMSCs.
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http://dx.doi.org/10.1016/j.neo.2014.12.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351298PMC
February 2015

Design of Fluorine-Containing 3,4-Diarylfuran-2(5H)-ones as Selective COX-1 Inhibitors.

ACS Med Chem Lett 2014 Nov 12;5(11):1254-8. Epub 2014 Oct 12.

A. B. Hancock, Jr., Memorial Laboratory for Cancer Research, Department of Biochemistry, Chemistry and Pharmacology, Vanderbilt Institute of Chemical Biology, Center for Molecular Toxicology and Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine , Nashville, Tennessee 37232, United States.

We report the design and synthesis of fluorine-containing cyclooxygenase-1 (COX-1)-selective inhibitors to serve as prototypes for the development of a COX-1-targeted imaging agent. Deletion of the SO2CH3 group of rofecoxib switches the compound from a COX-2- to a COX-1-selective inhibitor, providing a 3,4-diarylfuran-2(5H)-one scaffold for structure-activity relationship studies of COX-1 inhibition. A wide range of fluorine-containing 3,4-diarylfuran-2(5H)-ones were designed, synthesized, and tested for their ability to selectively inhibit COX-1 in purified protein and human cancer cell assays. Compounds containing a fluoro-substituent on the C-3 phenyl ring and a methoxy-substituent on the C-4 phenyl ring of the 3,4-diarylfuran-2(5H)-one scaffold were the best COX-1-selective agents of those evaluated, exhibiting IC50s in the submicromolar range. These compounds provide the foundation for development of an agent to facilitate radiologic imaging of ovarian cancer expressing elevated levels of COX-1.
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http://dx.doi.org/10.1021/ml500344jDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4233350PMC
November 2014

Kinetics of poliovirus shedding following oral vaccination as measured by quantitative reverse transcription-PCR versus culture.

J Clin Microbiol 2015 Jan 5;53(1):206-11. Epub 2014 Nov 5.

Division of Infectious Diseases and International Health, Department of Medicine, University of Virginia, Charlottesville, Virginia, USA.

Amid polio eradication efforts, detection of oral polio vaccine (OPV) virus in stool samples can provide information about rates of mucosal immunity and allow estimation of the poliovirus reservoir. We developed a multiplex one-step quantitative reverse transcription-PCR (qRT-PCR) assay for detection of OPV Sabin strains 1, 2, and 3 directly in stool samples with an external control to normalize samples for viral quantity and compared its performance with that of viral culture. We applied the assay to samples from infants in Dhaka, Bangladesh, after the administration of trivalent OPV (tOPV) at weeks 14 and 52 of life (on days 0 [pre-OPV], +4, +11, +18, and +25 relative to vaccination). When 1,350 stool samples were tested, the sensitivity and specificity of the quantitative PCR (qPCR) assay were 89 and 91% compared with culture. A quantitative relationship between culture(+)/qPCR(+) and culture(-)/qPCR(+) stool samples was observed. The kinetics of shedding revealed by qPCR and culture were similar. qPCR quantitative cutoffs based on the day +11 or +18 stool samples could be used to identify the culture-positive shedders, as well as the long-duration or high-frequency shedders. Interestingly, qPCR revealed that a small minority (7%) of infants contributed the vast majority (93 to 100%) of the total estimated viral excretion across all subtypes at each time point. This qPCR assay for OPV can simply and quantitatively detect all three Sabin strains directly in stool samples to approximate shedding both qualitatively and quantitatively.
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http://dx.doi.org/10.1128/JCM.02406-14DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290924PMC
January 2015
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