Lara Batičić

Neuroimmunomodulative properties of dipeptidyl peptidase IV/CD26 in a TNBS‐induced model of colitis in mice

Causal connections between dipeptidyl peptidase IV, also known as CD26 molecule (DPP IV/CD26) and inflammatory bowel disease (IBD) have been shown, but mechanisms of these interactions are unclear. Our hypothesis was that DPP IV/CD26 could affect the neuroimmune response during inflammatory events. Therefore, we aimed to evaluate its possible role and the relevance of the gut–brain axis in a model of IBD in mice. Trinitrobenzenesulfonic acid‐induced (TNBS) colitis was induced in CD26‐deficient (CD26−/−) and wild‐type (C57BL/6) mice. Pathohistological and histomorphometrical measurements were done. Concentrations and protein expressions of DPP IV/CD26 substrates neuropeptide Y (NPY) and vasoactive intestinal peptide (VIP) were determined. Concentrations of IL‐6 and IL‐10 were evaluated. Investigations were conducted at systemic and local levels. Acute inflammation induced increased serum NPY concentrations in both mice strains, more enhanced in CD26−/− mice. Increased NPY concentrations were found in colon and brain of C57BL/6 mice, while in CD26−/− animals only in colon. VIP and IL‐6 serum and tissue concentrations were increased in both mice strains in acute inflammation, more pronouncedly in CD26−/− mice. IL‐10 concentrations, after a decrease in serum of both mice strains, increased promptly in CD26−/− mice. Decreased IL‐10 concentration was found in brain of C57BL/6 mice, while it was increased in colon of CD26−/− mice in acute inflammation. DPP IV/CD26 deficiency affects the neuroimmune response at systemic and local levels during colitis development and resolution in mice. Inflammatory changes in the colon reflected on investigated parameters in the brain, suggesting an important role of the gut–brain axis in IBD pathogenesis. J. Cell. Biochem. 112: 3322–3333, 2011.

THE INFLUENCE OF AGE ON INTESTINAL DIPEPTIDYL PEPTIDASE IV (DPP IV/CD26), DISACCHARIDASES, AND ALKALINE PHOSPHATASE ENZYME ACTIVITY IN C57BL/6 MICE

The objective of this study was to determine and describe the age-related changes in intestinal brush border membrane enzyme activities that occur in C57Bl/6 mice. Specifically, jejunal, duodenal, and ileal dipeptidyl peptidase IV/CD26, disaccharidase (lactase, sucrase, and maltase), and alkaline phosphatase activities were determined. A significant correlation between analyzed intestinal brush border membrane enzyme activities and animal age was found. Our study revealed that intestinal dipeptidyl peptidase IV/CD26, lactase, sucrase, maltase, and alkaline phosphatase activities decline significantly with age (p < .05). Nevertheless, the horizontal (duodenum to ileum) enzyme activity patterns are not affected by age.

Fish Lipids as a Source of Healthy Components: Fatty Acids from Mediterranean Fish

From the time when the epidemiological work on Greenland Eskimos suggested a possible correlation between a low incidence of heart disease and the consumption of seafood, a considerable number of studies have been done on the role of n-3 polyunsaturated fatty acids (n-3 PUFA) in human health and diseases. A substantial number of experiments have indicated that consumption of fish oils rich in n-3 PUFA has different health benefits including cardiovascular health improving, properly fetal development, anti-inflammatory effects and chronic disease alleviation. The natural sources of n-3 PUFA are foremost fish lipids, especially those of marine origin. The two most important n-3 PUFA are eicosapentaenoic acid (20:5 n-3, EPA) and docosahexaenoic acid (22:6 n-3, DHA). EPA and DHA have been largely investigated and their positive biological effects have been demonstrated from feeding studies with fish or fish oil supplements. Therefore, the nutritional importance of fish consumption is associated with their n-3 PUFA components and the recommendation, particularly for high-risk populations, to increase the dietary intake of n-3 PUFA through the consumption of fish is justified. These findings have created a new market for fish oil as a source of healthy components. Many products based on fish oil fatty acids such as dietary supplements and pharmaceuticals as well as other products with technical and cosmetic applications based on fish oil fatty acids have been developed and produced commercially. Knowledge about the presence of important constituents and the fatty acid composition of the lipid fractions is essential in the assessment of diet evaluation. Likewise, data on fatty acid composition are needed by food scientists and nutritionists for dietary formulation, processing and product development. In the last decade a significant number of fatty acid compositional data for a number of marine, freshwater and cultured fish from different parts of the world have been published. However, fatty acid compositions of Mediterranean, especially Adriatic Sea fish species have not been investigated thoroughly. Therefore, the aim of this study was to determine and review the fatty acid compositions of the common two-banded seabream (Diplodus vulgaris, L.), the sea eel (Conger conger, L.) and the white seabream (Diplodus sargus, L.), which are appreciated fish species in the Mediterranean diet, and have an important place in the fishing activity of Mediterranean countries. This review deals with the fatty acid characterization of fish liver (D. vulgaris and D. sargus) and edible muscle tissue lipid fractions. The fatty acid compositions of neutral (triacylglycerols, TAG) and polar (phosphatidylinositol, PI ; phosphatidylserine, PS ; phosphatidylcholine, PC ; and phosphatidylethanolamine, PE) lipid classes were analyzed in different fish species in different seasons. The fatty acid composition showed a noticeable pattern of seasonality that reflected fluctuations mainly in neutral lipids. The results of this study indicated that analyzed fish species are a good source of natural n-3 PUFA and would therefore be suitable for inclusion in highly unsaturated low-fat diets. Likewise, fish lipids could serve as a good source of biomedically significant components if used as raw material for products based on fish oil fatty acids.