Monocytes treated with ciprofloxacin and oxyLDL express myristate,priming atherosclerosis

Antibiotics are essential in many life‐threatening diseases. On the other hand, improper use of antibiotics can be disastrous. Cell morphological changes were observed in the ciprofloxacin‐treated cells starting at 48 hours. Changes in cell morphology were continuously observed up to 14 days, which showed gradual morphological changes from monocyte to plaque‐like cells at day 12, and foam cell, which is an intermediate stage in atherosclerosis was observed at day 8, which was confirmed with Oil Red O staining. Flow cytometry data revealed that oxidized LDL (oxyLDL)‐induced cells showed 60.16% of CD64 (proinflammatory macrophage markers) and no expression of CD23 (anti‐inflammatory macrophage markers), whereas ciprofloxacin‐treated cells expressed 67.97% of CD64 and 13.78% of CD23. Chemokine antibody array analysis revealed that ciprofloxacin exposed cells showed a proinflammatory role (ENA78, Eotaxin1, Eotaxin2, IP‐10, MIG, MIP‐3β, SDF‐1β, TECK, CXCL16, and Fractalkine). Liquid chromatography with tandem mass spectrometry (LC‐MS/MS) revealed that myristic acid was incorporated into a protein with 68 kDa molecular mass in exposing oxyLDL‐induced monocytes with ciprofloxacin, which could be a reason for the observed foam cells and in vitro plaque formation. As myristic acid primes atherosclerosis, it is better to limit the intake of antibiotics like ciprofloxacin for common illness, specifically the high‐risk patients, which may contribute to atherosclerosis.     

Up-regulation of MUC2 and IL-1β expression in human colonic epithelial cells by Shigella and its interaction with mucins

Background

The entire gastrointestinal tract is protected by a mucous layer, which contains complex glycoproteins called mucins. MUC2 is one such mucin that protects the colonic mucosa from invading microbes. The initial interaction between microbes and mucins is an important step for microbial pathogenesis. Hence, it was of interest to investigate the relationship between host (mucin) and pathogen interaction, including Shigella induced expression of MUC2 and IL-1β during shigellosis.

Methods

The mucin-Shigella interaction was revealed by an in vitro mucin-binding assay. Invasion of Shigella dysenteriae into HT-29 cells was analyzed by Transmission electron microscopy. Shigella induced mucin and IL-1β expression were analyzed by RT-PCR and Immunofluorescence.

Results

The clinical isolates of Shigella were found to be virulent by a congo-red binding assay. The in vitro mucin-binding assay revealed both Shigella dysenteriae and Shigella flexneri have binding affinity in the increasing order of: guinea pig small intestinal mucinShigella dysenteriae into HT-29 cells occurs within 2 hours. Interestingly, in Shigella dysenteriae infected conditions, significant increases in mRNA expression of MUC2 and IL-1β were observed in a time dependent manner. Further, immunofluorescence analysis of MUC2 shows more positive cells in Shigella dysenteriae treated cells than untreated cells.

Conclusions

Our study concludes that the Shigella species specifically binds to guinea pig colonic mucin, but not to guinea pig small intestinal mucin. The guinea pig colonic mucin showed a greater binding parameter (R), and more saturable binding, suggesting the presence of a finite number of receptor binding sites in the colonic mucin of the host. In addition, modification of mucins with TFMS and sodium metaperiodate significantly reduced mucin-bacterial binding; suggesting that the mucin-Shigella interaction occurs through carbohydrate epitopes on the mucin backbones. Overproduction of MUC2 may alter adherence and invasion of Shigella dysenteriae into human colonic epithelial cells.     

Provision of nestboxes raises the breeding density of Great Tits Parus major equally in coniferous and deciduous woodland

Nestbox provision is a technique used to increase nest-site availability for secondary cavity-nesting birds. However, little is known about the demographic consequences of nestbox provision in different habitat types. To assess how nestbox provision affects the density of hole-nesting birds simultaneously in two contrasting habitats, we compared the breeding density of Great Tits along transects without nestboxes with that in transects where nestboxes were provided. Although the initial density of breeders was considerably higher in the deciduous habitat than in the coniferous habitat, provision of nestboxes increased density by a similar number of additional pairs in each habitat type. Thus, the provision of nestboxes in managed coniferous forests may be as effective in increasing the breeding opportunities of cavity nesters as in deciduous stands. Moreover, previous research showed that pairs in deciduous habitat with nestboxes have consistently lower breeding success than those in coniferous habitat with nestboxes. It is possible that the addition of nestboxes in the preferred habitat increased density to such an extent that density-dependent effects became apparent.     

Apoptosis inducing effect of plumbagin on colonic cancer cells depends on expression of COX-2

Plumbagin, a quinonoid found in the plants of the Plumbaginaceae, possesses medicinal properties. In this study we investigated the anti-proliferative and apoptotic activity of plumbagin by using two human colonic cancer cell lines, HT29 and HCT15. IC50 of Plumbagin for HCT15 and HT29 cells (22.5 μM and 62.5 μM, respectively) were significantly different. To study the response of cancer cells during treatment strategies, cells were treated with two different concentrations, 15 μM, 30 μM for HCT15 and 50 μM, 75 μM for HT29 cells. Though activation of NFκB, Caspases-3, elevated levels of TNF-α, cytosolic Cytochrome C were seen in both HCT15 cells HT29 treated with plumbagin, aberrant apoptosis with decreased level of pEGFR, pAkt, pGsk-3β, PCNA and Cyclin D1was observed only in 15 μM and 30 μM plumbagin treated HCT15 and 75 μM plumbagin treated HT29 cells. This suggests that plumbagin induces apoptosis in both HCT15 cells and HT29 treated, whereas, proliferation was inhibited only in 15 μM and 30 μM plumbagin treated HCT15 and 75 μM plumbagin treated HT29 cells, but not in 50 μM plumbagin treated HT29 cells. Expression of COX-2 was decreased in 75 μM plumbagin treated HT29 cells when compared to 50 μM plumbagin treated HT29 cells, whereas HCT15 cells lack COX. Hence the observed resistance to induction of apoptosis in 50 μM plumbagin treated HT29 cells are attributed to the expression of COX-2. In conclusion, plumbagin induces apoptosis in colonic cancer cells through TNF-α mediated pathway depending on expression of COX-2 expression.     

Attenuation of N-nitrosodiethylamine-induced hepatocellular carcinogenesis by a novel flavonol-Morin

Morin (3,5,7,2′,4′-pentahydroxyflavone), a plant-derived flavonoid belonging to the subclass of flavonol is believed to play a role in chemoprevention and cancer chemotherapy. In this study, we found that the cotreatment of morin (500 ppm in diet) for 16 weeks to N-nitosodiethylamine-induced (200 mg/kg bodyweight in drinking water) rats provides protection against the oxidative stress caused by the carcinogen and thereby prevents hepatocellular carcinogenesis. On administration of the carcinogen, the level of lipid peroxidation increased markedly, but was found to be significantly lowered by morin treatment. On the contrary, the antioxidant levels in both liver and serum were decreased in carcinogen-administered animals, which was improved to normalcy upon morin administration. Cotreatment with morin prevented the elevation of marker enzymes induced by N-nitrosodiethylamine. The body weight of the animals decreased and their relative liver weight increased significantly on N-nitrosodiethylamine administration when compared to control group. However, cotreatment with morin significantly prevented the decrease of the body weight and increase in relative liver weight caused by DEN. Histological observations of liver tissue too correlated with the biochemical observations. In conclusion, these findings indicate that morin prevents lipid peroxidation, hepatic cell damage and protects the antioxidant system in N-nitrosodiethylamine-induced hepatocellular carcinogenesis.