Investigations into the Influence of Chronic Colitis on Colonic Adenocarcinoma Cell Growth A Progress Report

Graduate Basi

Colitis Induced Microvascular Leak Triggers Colonic Dysmotility

Graduate Basi

Cyclosporin A differentially inhibits multiple steps in VEGF induced angiogenesis in human microvascular endothelial cells through altered intracellular signaling

The immunosuppressive agent cyclosporin A (CsA), a calcineurin inhibitor which blocks T cell activation has provided the pharmacologic foundation for organ transplantation. CsA exerts additional effects on non-immune cell populations and may adversely effect microvascular endothelial cells, contributing to chronic rejection, a long-term clinical complication and significant cause of mortality in solid-organ transplants, including patients with small bowel allografts. Growth of new blood vessels, or angiogenesis, is a critical homeostatic mechanism in organs and tissues, and regulates vascular populations in response to physiologic requirements. We hypothesized that CsA would inhibit the angiogenic capacity of human gut microvessels. Primary cultures of human intestinal microvascular endothelial cells (HIMEC) were used to evaluate CsA's effect on four in vitro measures of angiogenesis, including endothelial stress fiber assembly, migration, proliferation and tube formation, in response to the endothelial growth factor VEGF. We characterized the effect of CsA on intracellular signaling mechanisms following VEGF stimulation. CsA affected all VEGF induced angiogenic events assessed in HIMEC. CsA differentially inhibited signaling pathways which mediated distinct steps of the angiogenic process. CsA blocked VEGF induced nuclear translocation of the transcription factor NFAT, activation of p44/42 MAPK, and partially inhibited JNK and p38 MAPK. CsA differentially affected signaling cascades in a dose dependent fashion and completely blocked expression of COX-2, which was integrally linked to HIMEC angiogenesis. These data suggest that CsA inhibits the ability of microvascular endothelial cells to undergo angiogenesis, impairing vascular homeostatic mechanisms and contributing to the vasculopathy associated with chronic rejection

Oral Citrobacter-Secreting Shiga Toxin as a Model of Murine Shigellosis

Undergraduate Basi

Effect of Adalimumab on Work Productivity and Indirect Costs in Moderate to Severe Crohn’s Disease: A Meta-Analysis

peer reviewedOBJECTIVE: To assess the effect of adalimumab on work productivity and indirect costs in patients with Crohn's disease (CD) using a meta-analysis of clinical trials. METHODS: Study-level results were pooled from all clinical trials of adalimumab for moderate to severe CD in which work productivity outcomes were evaluated. Work Productivity and Activity Impairment Questionnaire outcomes (absenteeism, presenteeism and total work productivity impairment [TWPI]) were extracted from adalimumab trials. Meta-analyses were used to estimate pooled averages and 95% CIs of one-year accumulated reductions in work productivity impairment with adalimumab. Pooled averages were multiplied by the 2008 United States national average annual salary ($44,101) to estimate per-patient indirect cost savings during the year following adalimumab initiation. RESULTS: The four included trials (ACCESS, CARE, CHOICE and EXTEND) represented a total of 1202 employed adalimumab-treated patients at baseline. Each study followed patients for a minimum of 20 weeks. Pooled estimates (95$3,856 ($3,183 to$4,529) and $10,964 ($8,833 to $13,096), respectively. CONCLUSION: Adalimumab provided clinically meaningful improvements in work productivity among patients with moderate to severe CD, which may translate into substantial indirect cost savings from an employer's perspective

L-arginine Supplementation Improves Responses to Injury and Inflammation in Dextran Sulfate Sodium Colitis

Inflammatory bowel disease (IBD), consisting of Crohn's disease and ulcerative colitis (UC), results in substantial morbidity and is difficult to treat. New strategies for adjunct therapies are needed. One candidate is the semi-essential amino acid, L-arginine (L-Arg), a complementary medicine purported to be an enhancer of immunity and vitality in the lay media. Using dextran sulfate sodium (DSS) as a murine colonic injury and repair model with similarities to human UC, we assessed the effect of L-Arg, as DSS induced increases in colonic expression of the y+ cationic amino acid transporter 2 (CAT2) and L-Arg uptake. L-Arg supplementation improved the clinical parameters of survival, body weight loss, and colon weight, and reduced colonic permeability and the number of myeloperoxidase-positive neutrophils in DSS colitis. Luminex-based multi-analyte profiling demonstrated that there was a marked reduction in proinflammatory cytokine and chemokine expression with L-Arg treatment. Genomic analysis by microarray demonstrated that DSS-treated mice supplemented with L-Arg clustered more closely with mice not exposed to DSS than to those receiving DSS alone, and revealed that multiple genes that were upregulated or downregulated with DSS alone exhibited normalization of expression with L-Arg supplementation. Additionally, L-Arg treatment of mice with DSS colitis resulted in increased ex vivo migration of colonic epithelial cells, suggestive of increased capacity for wound repair. Because CAT2 induction was sustained during L-Arg treatment and inducible nitric oxide (NO) synthase (iNOS) requires uptake of L-Arg for generation of NO, we tested the effect of L-Arg in iNOS−/− mice and found that its benefits in DSS colitis were eliminated. These preclinical studies indicate that L-Arg supplementation could be a potential therapy for IBD, and that one mechanism of action may be functional enhancement of iNOS activity

NKX2-3 Transcriptional Regulation of Endothelin-1 and VEGF Signaling in Human Intestinal Microvascular Endothelial Cells

BACKGROUND: NKX2-3 is associated with inflammatory bowel disease (IBD). NKX2-3 is expressed in microvascular endothelial cells and the muscularis mucosa of the gastrointestinal tract. Human intestinal microvascular endothelial cells (HIMECs) are actively involved in the pathogenesis of IBD and IBD-associated microvascular dysfunction. To understand the cellular function of NKX2-3 and its potential role underlying IBD pathogenesis, we investigated the genes regulated by NKX2-3 in HIMEC using cDNA microarray. METHODOLOGY/PRINCIPAL FINDINGS: NKX2-3 expression was suppressed by shRNA in two HIMEC lines and gene expression was profiled by cDNA microarray. Pathway Analysis was used to identify gene networks according to biological functions and associated pathways. Validation of microarray and genes expression in intestinal tissues was assessed by RT-PCR. NKX2-3 regulated genes are involved in immune and inflammatory response, cell proliferation and growth, metabolic process, and angiogenesis. Several inflammation and angiogenesis related signaling pathways that play important roles in IBD were regulated by NKX2-3, including endothelin-1 and VEGF-PI3K/AKT-eNOS. Expression levels of NKX2-3, VEGFA, PI3K, AKT, and eNOS are increased in intestinal tissues from IBD patients and expression levels of EDN1 are decreased in intestinal tissues from IBD patients. These results demonstrated the important roles of NKX2-3, VEGF, PI3K, AKT, eNOS, and EDN1 in IBD pathogenesis. Correlation analysis showed a positive correlation between mRNA expression of NKX2-3 and VEGFA and a negative correlation between mRNA expression of NKX2-3 and EDN1 in intestinal tissues from IBD patients. CONCLUSION/RELEVANCE: NKX2-3 may play an important role in IBD pathogenesis by regulating endothelin-1 and VEGF signaling in HIMECs

The Tissue Microlocalisation and Cellular Expression of CD163, VEGF, HLA-DR, iNOS, and MRP 8/14 Is Correlated to Clinical Outcome in NSCLC

BACKGROUND: We have previously investigated the microlocalisation of M1 and M2 macrophages in NSCLC. This study investigated the non-macrophage (NM) expression of proteins associated with M1 and M2 macrophages in NSCLC. METHODS: Using immunohistochemistry, CD68(+) macrophages and proteins associated with either a cytotoxic M1 phenotype (HLA-DR, iNOS, and MRP 8/14), or a non-cytotoxic M2 phenotype (CD163 and VEGF) were identified. NM expression of the markers was analysed in the islets and stroma of surgically resected tumours from 20 patients with extended survival (ES) (median 92.7 months) and 20 patients with poor survival (PS) (median 7.7 months). RESULTS: The NM expression of NM-HLA-DR (p<0.001), NM-iNOS (p = 0.02) and NM-MRP 8/14 (p = 0.02) was increased in ES compared to PS patients in the tumour islets. The tumour islet expression of NM-VEGF, was decreased in ES compared to PS patients (p<0.001). There was more NM-CD163 expression (p = 0.04) but less NM-iNOS (p = 0.002) and MRP 8/14 (p = 0.01) expression in the stroma of ES patients compared with PS patients. The 5-year survival for patients with above and below median NM expression of the markers in the islets was 74.9% versus 4.7% (NM-HLA-DR p<0.001), 65.0% versus 14.6% (NM-iNOS p = 0.003), and 54.3% versus 22.2% (NM-MRP 8/14 p = 0.04), as opposed to 34.1% versus 44.4% (NM-CD163 p = 0.41) and 19.4% versus 59.0% (NM-VEGF p = 0.001). CONCLUSIONS: Cell proteins associated with M1 and M2 macrophages are also expressed by other cell types in the tumour islets and stroma of patients with NSCLC. Their tissue and cellular microlocalisation is associated with important differences in clinical outcome