sphingosine-kinase and Colitis--Ulcerative

Patients with ulcerative colitis (UC) experience diarrhoea, hematochezia and abdominal pain. UC is a well-known health challenge affecting 200-250 per 100 000 individuals worldwide, with a similar prevalence in both sexes and elevated upon activation of gut immune responses. We evaluated the potential therapeutic effects of cycloastragenol in experimentally induced UC rats and examined the modulation of sphingosine kinase (SphK), macrophage inflammatory protein (MIP)-1α and miR-143. We treated UC rats with 30 mg/kg cycloastragenol and assessed gene and protein expression levels of SphK, MIP-1α, B-cell lymphoma 2 (BCL2), BCL2-associated X (BAX), miR-143, NF-κB, tumour necrosis factor (TNF)-α and active caspase-3. Colon sections were examined using electron microscopy; additional sections were stained with haematoxylin-eosin or immunostained with anti-TNF-α and anti-caspase-3 antibodies. Electron microscopy of UC specimens revealed dark distorted goblet cell nuclei with disarranged mucus granules and a nondistinct brush border with atypical microvilli. Haematoxylin-eosin staining showed damaged intestinal glands, severe haemorrhage and inflammatory cell infiltration. Cycloastragenol treatment improved the induced morphological changes. In UC rats, cycloastragenol significantly reduced expression levels of SphK, MIP-1α, BAX, NF-κB, TNF-α and active caspase-3, associated with BCL2 and miR-143 overexpression. Therefore, cycloastragenol protects against UC by modulating SphK/MIP-1α/miR-143, subsequently deactivating inflammatory and apoptotic pathways.

Topics: Animals; bcl-2-Associated X Protein; Chemokine CCL3; Colitis, Ulcerative; Eosine Yellowish-(YS); Female; Male; MicroRNAs; NF-kappa B; Phosphotransferases (Alcohol Group Acceptor); Rats; Sapogenins; Tumor Necrosis Factor Inhibitors; Tumor Necrosis Factor-alpha

Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is associated with high sphingosine kinase 1(SPHK1) expression in the colon, however its role in pathogenesis of UC is not clearly understood so, the aim of the present study was to clarify the role of SPHK1 and investigate whether the anti-inflammatory effects of metformin in UC is mediated by Sphingosine kinase 1/sphingosine 1 phosphate (S1P) signaling pathway.. Colitis was induced in adult male wistar rats by intra rectal administration of oxazolone in the fifth and seventh days from initial presensitization. Oxazolone treated rats were divided into untreated oxazolone group, metformin and mesalazine treated groups both in a dose of 100 mg/kg/day orally for 21 days. Along with these groups normal control and saline groups were used .Colitis was assessed by colon length, disease activity index (DAI) and histological examination of colontissue. Plasma samples were used to measure S1P.SPHK1 activity, signal transducer and activator of transcription -3(STAT-3), interleukin-6 (IL-6), nitric oxide (NO), myeloperoxidase activity (MPO), reduced glutathione (GSH) and tissue expression of intracellular cell adhesion molecule -1(ICAM-1) and caspase-3 genes were measured in tissue.. Metformin successfully attenuated oxazolone colitis by increasing colon length, decreasing DAI and improved colon histologic picture. Metformin also induced a significant decrease in Plasma SIP, SPHK1 activity, inflammatory, oxidative stress markers, ICAM-1 and Caspase-3 genes expression compared to oxazolone group.. It is revealed that metformin alleviated inflammation and underlying mechanism may result from inhibition of SPHK1/S1P signaling pathway.

Topics: Animals; Colitis, Ulcerative; Colon; Inflammation; Lysophospholipids; Male; Metformin; Oxazolone; Phosphotransferases (Alcohol Group Acceptor); Rats; Rats, Wistar; Signal Transduction; Sphingosine

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder (IBD) that has an elevated risk of developing into colon cancer. In trials to develop new therapeutic alternatives for UC, it is important to fulfill modifying effects on pathogenic targets and to reach the colon in a high concentration. Thus, the current work has investigated a colon-specific delivery formula of resveratrol in targeting sphingosine kinase 1 (SphK1) and apoptotic pathways to control pathogenesis and its progression to any expected neoplasm. This work was conducted on 40 Wister albino rats equally divided into 4 groups where group I served as the normal control group. The untreated oxazolone-induced colitis in group II exhibited significant increase in SphK1 activity as well as activity of both myeloperoxidase (MPO) and caspase-3 with concomitant mild DNA fragmentation in colonic tissue. Colonic SphK1 activity showed significant positive correlation with the disease activity index (DAI) and histopathological score in this group. Comparable with treatment by the native resveratrol formula, nRes (group III), treatment by the colon-specific delivery resveratrol formula, cRes (group IV) caused significant decrease in the activity of SphK1 and MPO with massive DNA fragmentation in colonic tissue and non significant change in caspase-3 activity. The lowest DAI and histopathological score have been recorded in the group treated by the colon-specific delivery resveratrol formula. In conclusion, the anti-inflammatory and apoptotic effects of resveratrol could be attributed to its inhibitory effect on sphingosine kinase 1 (SphK1) providing a useful therapeutic tool to break the link between inflammation and carcinogenesis risk in ulcerative colitis.

Topics: Animals; Apoptosis; Caspase 3; Chemistry, Pharmaceutical; Colitis, Ulcerative; Colon; DNA Fragmentation; Drug Delivery Systems; Humans; Molecular Targeted Therapy; Organ Specificity; Oxazolone; Peroxidase; Phosphotransferases (Alcohol Group Acceptor); Rats; Rats, Wistar; Resveratrol; Stilbenes

The bioactive lipid sphingosine-1-phosphate (S1P) is emerging as an important mediator of immune and inflammatory responses. S1P formation is catalyzed by sphingosine kinase (SK), of which the SK1 isoenzyme is activated by tumor necrosis alpha (TNF-alpha). SK1 has been shown to be required for mediating TNF-alpha inflammatory responses in cells, including induction of cyclooxygenase 2 (COX-2). Because TNF-alpha and COX-2 are increased in patients with inflammatory bowel disease (IBD), we investigated the role of SK1 in a murine model of colitis. SK1(-/-) mice treated with dextran sulfate sodium (DSS) had significantly less blood loss, weight loss, colon shortening, colon histological damage, and splenomegaly than did wild-type (WT) mice. In addition, SK1(-/-) mice had no systemic inflammatory response. Moreover, WT but not SK1(-/-) mice treated with dextran sulfate sodium had significant increases in blood S1P levels, colon SK1 message and activity, and colon neutrophilic infiltrate. Unlike WT mice, SK1(-/-) mice failed to show colonic COX-2 induction despite an exaggerated TNF-alpha response; thus implicating for the first time SK1 in TNF-alpha-mediated COX-2 induction in vivo. Inhibition of SK1 may prove to be a valuable therapeutic target by inhibiting systemic and local inflammation in IBD.

Topics: Animals; Body Weight; Colitis; Colitis, Ulcerative; Colon; Cyclooxygenase 2; Dextran Sulfate; Erythrocytes; Gene Expression Regulation; Humans; Lysophospholipids; Mice; Mice, Inbred C57BL; Mice, Knockout; Organ Size; Phosphotransferases (Alcohol Group Acceptor); Sphingosine; Spleen; Tumor Necrosis Factor-alpha

A critical step in the mechanism of action of inflammatory cytokines is the stimulation of sphingolipid metabolism, including activation of sphingosine kinase (SK), which produces the mitogenic and proinflammatory lipid sphingosine 1-phosphate (S1P). We have developed orally bioavailable compounds that effectively inhibit SK activity in vitro in intact cells and in cancer models in vivo. In this study, we assessed the effects of these SK inhibitors on cellular responses to tumor necrosis factor alpha (TNFalpha) and evaluated their efficacy in the dextran sulfate sodium (DSS) model of ulcerative colitis in mice. Using several cell systems, it was shown that the SK inhibitors block the ability of TNFalpha to activate nuclear factor kappa B (NFkappaB), induce expression of adhesion proteins, and promote production of prostaglandin E(2) (PGE(2)). In an acute model of DSS-induced ulcerative colitis, SK inhibitors were equivalent to or more effective than Dipentum in reducing disease progression, colon shortening, and neutrophil infiltration into the colon. The effects of SK inhibitors were associated with decreased colonic levels of inflammatory cytokines TNFalpha, interleukin (IL)-1beta, interferon gamma (IFN)-gamma, IL-6, and reduction of S1P levels. A similar reduction in disease progression was provided by SK inhibitors in a chronic model of ulcerative colitis in which the mice received 3-week-long cycles of DSS interspaced with week-long recovery periods. In the chronic model, immunohistochemistry for SK showed increased expression in DSS-treated mice (compared with water-treated controls) that was reduced by drug treatment. S1P levels were also elevated in the DSS group and significantly reduced by drug treatment. Together, these data indicate that SK is a critical component in inflammation and that inhibitors of this enzyme may be useful in treating inflammatory bowel diseases.

Topics: Administration, Oral; Animals; Colitis, Ulcerative; Cytokines; Dextran Sulfate; Disease Models, Animal; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Phosphotransferases (Alcohol Group Acceptor); Tumor Necrosis Factor-alpha