Human noroviruses are the major cause of nonbacterial epidemic gastroenteritis worldwide. However, little is known regarding their pathogenesis or the immune responses that control them because until recently there has been no small animal model or cell culture system of norovirus infection. We recently reported the discovery of the first murine norovirus, murine norovirus 1 (MNV-1), and its cultivation in macrophages and dendritic cells in vitro. We further defined interferon receptors and the STAT-1 molecule as critical in both resistance to MNV-1-induced disease in vivo and control of virus growth in vitro. To date, neither histopathological changes upon infection nor viral replication in wild-type mice has been shown. Here we extend our studies to demonstrate that MNV-1 replicates and rapidly disseminates to various tissues in immunocompetent mice and that infection is restricted by STAT1-dependent interferon responses at the levels of viral replication and virus dissemination. Infection of wild-type mice is associated with histopathological alterations in the intestine (mild inflammation) and the spleen (red pulp hypertrophy and white pulp activation); viral dissemination to the spleen, liver, lung, and lymph nodes; and low-level persistent infection in the spleen. STAT-1 inhibits viral replication in the intestine, prevents virus-induced apoptosis of intestinal cells and splenocytes, and limits viral dissemination to peripheral tissues. These findings demonstrate that murine norovirus infection of wild-type mice is associated with initial enteric seeding and subsequent extraintestinal spread, and they provide mechanistic evidence of the role of STAT-1 in controlling clinical norovirus-induced disease.

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the intestinal tract with unknown multifactorial etiology that, among other things, result in alteration and dysfunction of the intestinal microvasculature. Clinical observations of increased colon microvascular density during IBD have been made. However, there have been no reports investigating the physiological or pathological importance of angiogenic stimulation during the development of intestinal inflammation. Here we report that the dextran sodium sulfate and CD4+CD45RBhigh T-cell transfer models of colitis stimulate angiogenesis that results in increased blood vessel density concomitant with increased histopathology, suggesting that the neovasculature contributes to tissue damage during colitis. We also show that leukocyte infiltration is an obligatory requirement for the stimulation of angiogenesis. The angiogenic response during experimental colitis was differentially regulated in that the production of various angiogenic mediators was diverse between the two models with only a small group of molecules being similarly controlled. Importantly, treatment with the anti-angiogenic agent thalidomide or ATN-161 significantly reduced angiogenic activity and associated tissue histopathology during experimental colitis. Our findings identify a direct pathological link between angiogenesis and the development of experimental colitis, representing a novel therapeutic target for IBD.

Chidlow JH Jr, Shukla D, Grisham MB, Kevil CG. Pathogenic angiogenesis in IBD and experimental colitis: new ideas and therapeutic avenues. Am J Physiol Gastrointest Liver Physiol 293: G5-G18, 2007. First published April 26, 2007; doi:10.1152/ajpgi.00107.2007.-Angiogenesis is now understood to play a major role in the pathology of chronic inflammatory diseases and is indicated to exacerbate disease pathology. Recent evidence shows that angiogenesis is crucial during inflammatory bowel disease (IBD) and in experimental models of colitis. Examination of the relationship between angiogenesis and inflammation in experimental colitis shows that initiating factors for these responses simultaneously increase as disease progresses and correlate in magnitude. Recent studies show that inhibition of the inflammatory response attenuates angiogenesis to a similar degree and, importantly, that inhibition of angiogenesis does the same to inflammation. Recent data provide evidence that differential regulation of the angiogenic mediators involved in IBD-associated chronic inflammation is the root of this pathological angiogenesis. Many factors are involved in this phenomenon, including growth factors/cytokines, chemokines, adhesion molecules, integrins, matrix-associated molecules, and signaling targets. These factors are produced by various vascular, inflammatory, and immune cell types that are involved in IBD pathology. Moreover, recent studies provide evidence that antiangiogenic therapy is a novel and effective approach for IBD treatment. Here we review the role of pathological angiogenesis during IBD and experimental colitis and discuss the therapeutic avenues this recent knowledge has revealed. inflammation; T cells; growth factors; adhesion molecules; antiangiogenesis ANGIOGENESIS PLAYS AN IMPORTANT role in many chronic inflammatory diseases including but not limited to diabetic retinopathy, atherosclerosis, rheumatoid arthritis, hypercholesterolemia, and psoriasis. It has been suggested that the angiogenic components of these diseases contribute to and exacerbate disease conditions (26, 31). Recent findings, both clinical and experimental, indicate that angiogenesis also plays a crucial role in the inflammatory bowel diseases (IBD), consisting of Crohn's disease (CD) and ulcerative colitis (UC) (31,37,58,131,155). Development of new vasculature during chronic inflammation may play a negative "pathological" role by contributing to increased inflammatory responses due to dysfunctional new vessel architecture and increases in the recruitment of inflammatory cell types. Importantly, recent data have shown that angiogenic inhibition during chronic inflammatory diseases attenuates further inflammation and disease pathology (31, 37, 51). As such, expanding our knowledge of how pathological angiogenesis occurs during IBD will further our ability to treat patients with these diseases. IBD PathogenesisCD and UC are idiopathic inflammatory disorders of the intestine and/or colon in which patients suffer from rectal bleeding, severe...

BACKGROUND Expression of metallothionein isoform 3 (MT‐3) was initially reported to be confined to neural tissues. However, it was recently demonstrated that MT‐3 is expressed in epithelial cells of the human kidney. This motivated the current examination of the expression of MT‐3 in the human prostate. METHODS Immunohistochemistry (IHC) was used to localize the expression of MT‐3, RT‐PCR to determine the expression of MT‐3 mRNA, and Western blot analysis to determine the level of MT‐3 protein. RESULTS Selected epithelial and stromal cells of the normal human prostate were shown to have low levels of MT‐3 expression. MT‐3 was increased in prostatic intraepithelial neoplasia (PIN) lesions and further increased in a highly variable fashion in prostatic adenocarcinoma. In some adenocarcinomas, MT‐3 expression exceeded that of nerve. Three cell culture models of prostate cancer were also shown to variably express MT‐3. Restriction enzyme analysis confirmed the expression of MT‐3 in the cells and tissues. CONCLUSIONS MT‐3 is expressed in the normal human prostate, and expression is enhanced and highly variable in PIN lesions and primary prostate cancer cells. The variable nature of MT‐3 expression was also noted in commonly utilized prostate cancer cell lines. Prostate 41:196–202, 1999. © 1999 Wiley‐Liss, Inc.

Background & Aims Increased vascular density has been associated with progression of human inflammatory bowel diseases (IBDs) and animal models of colitis. Pathologic angiogenesis in chronically inflamed tissues is mediated by several factors that are regulated at specialized lipid rafts known as caveolae. Caveolin-1 (Cav-1), the major structural protein of caveolae in endothelial cells, is involved in the regulation of angiogenesis, so we investigated its role in experimental colitis. Methods Colitis was induced by administration of dextran sodium sulfate to wild-type and Cav-1−/− mice, as well as Cav-1−/− mice that overexpress Cav-1 only in the endothelium. Colon tissues were analyzed by histologic analyses. Leukocyte recruitment was analyzed by intravital microscopy; angiogenesis was evaluated by immunohistochemistry and in vivo disk assays. Results Cav-1 protein levels increased after the induction of colitis in wild-type mice. In Cav-1−/− mice or mice given a Cav-1 inhibitory peptide, the colitis histopathology scores, vascular densities, and levels of inflammatory infiltrates decreased significantly compared with controls. Lower levels of leukocyte and platelet rolling and adhesion colitis also were observed in Cav-1−/− mice and mice given a Cav-1 inhibitory peptide, compared with controls. Cav-1−/− mice that received transplants of wild-type bone marrow had a lower colitis score than wild-type mice. Data from mice that overexpress Cav-1 only in the endothelium indicated that endothelial Cav-1 is the critical regulator of colitis. Genetic deletion or pharmacologic inhibition of endothelial Cav-1 also significantly decreased vascular densities and angiogenesis scores, compared with controls. Conclusions Endothelial Cav-1 mediates angiogenesis in experimental colitis. Modulation of Cav-1 could provide a novel therapeutic target for IBD.