Celso R. Belmiro

Unfractionated Heparin and New Heparin Analogues from Ascidians (Chordate-Tunicate) Ameliorate Colitis in Rats

The anti-inflammatory effect of mammalian heparin analogues, named dermatan sulfate and heparin, isolated from the ascidian Styela plicata was accessed in a TNBS-induced colitis model in rats. Subcutaneous administration of the invertebrate compounds during a 7-day period drastically reduced inflammation as observed by the normalization of the macroscopic and histological characteristics of the colon. At the molecular level, a decrease in the production of TNF-α, TGF-β, and VEGF was observed, as well as a reduction of NF-κB and MAPK kinase activation. At the cellular level, the heparin analogues attenuated lymphocyte and macrophage recruitment and epithelial cell apoptosis. A drastic reduction in collagen-mediated fibrosis was also observed. No hemorrhagic events were observed after glycan treatment. These results strongly indicate the potential therapeutic use of these compounds for the treatment of colonic inflammation with a lower risk of hemorrhage when compared with mammalian heparin.

Biochemical and immunohistochemical analysis of glycosaminoglycans in inflamed and non-inflamed intestinal mucosa of patients with Crohn’s disease

ObjectivesChanges in extracellular matrix glycosaminoglycans (GAGs) of the intestinal mucosa have been associated with inflammatory bowel disease. The aim of the present study was to follow the changes in GAGs metabolism during the progression from non-inflamed to inflamed intestinal colon of patients with Crohn’s disease (CD), using direct biochemical analysis and specific immunohistochemistry against chondroitin/dermatan sulfate and heparan sulfate.Design and methodsThe content of GAGs from inflamed and non-inflamed colon of eight patients with active CD was estimated by uronic acid per dry weight of tissue and analyzed by agarose gel electrophoresis and ion-exchange chromatography. Intestinal sections were stained using antibodies against dermatan sulfate/chondroitin 4-sulfate (DS/CS), heparan sulfate (HS), and ICAM-1 (CD54), and analyzed by confocal microscopy.ResultsThere was a reduction in the amount of GAGs in the non-inflamed colon of patients with CD. In the inflamed colon, HS, CS and DS showed increased concentrations compared with the non-inflamed colon. GAGs showed a diffuse distribution in the lamina propria and in the basement membrane of both inflamed and non-inflamed mucosa of patients with CD.ConclusionWe observed a marked reduction in GAGs with altered patterns of distribution in the non-inflamed colon of patients with CD. The increase in the synthesis of GAGs observed in the inflamed colon may be a compensatory mechanism for the restoration of the integrity of the intestinal mucosa.

Biochemical and toxicological evaluation of nano-heparins in cell functional properties, proteasome activation and expression of key matrix molecules.

The glycosaminoglycan heparin and its derivatives act strongly on blood coagulation, controlling the activity of serine protease inhibitors in plasma. Nonetheless, there is accumulating evidence highlighting different anticancer activities of these molecules in numerous types of cancer. Nano-heparins may have great biological significance since they can inhibit cell proliferation and invasion as well as inhibiting proteasome activation. Moreover, they can cause alterations in the expression of major modulators of the tumor microenvironment, regulating cancer cell behavior. In the present study, we evaluated the effects of two nano-heparin formulations: one isolated from porcine intestine and the other from the sea squirt Styela plicata, on a breast cancer cell model. We determined whether these nano-heparins are able to affect cell proliferation, apoptosis and invasion, as well as proteasome activity and the expression of extracellular matrix molecules. Specifically, we observed that nano-Styela compared to nano-Mammalian analogue has higher inhibitory role on cell proliferation, invasion and proteasome activity. Moreover, nano-Styela regulates cell apoptosis, expression of inflammatory molecules, such as IL-6 and IL-8 and reduces the expression levels of extracellular matrix macromolecules, such as the proteolytic enzymes MT1-MMP, uPA and the cell surface proteoglycans syndecan-1 and -2, but not on syndecan-4. The observations reported in the present article indicate that nano-heparins and especially ascidian heparin are effective agents for heparin-induced effects in critical cancer cell functions, providing an important possibility in pharmacological targeting.

Leishmaniasis and glycosaminoglycans: a future therapeutic strategy?

Leishmania spp. depend on effective macrophage infection to establish and develop in mammalian hosts. Both metacyclic promastigotes and amastigotes are able to infect host cells, and thus they rely on several ligands that, when recognized by macrophage receptors, mediate parasite uptake. During macrophage primary infection with metacyclic forms from the insect vector and during amastigote dissemination via macrophage rupture, both infective stages have to cope with the host extracellular microenvironment, including extracellular matrix molecules. Glycosaminoglycans are abundant in the extracellular matrix and many of these molecules are able to interact with the parasite and the host cell, mediating positive and negative effects for the infection, depending on their structure and/or location. In addition, glycosaminoglycans are present at the surface of macrophages as proteoglycans, playing important roles for parasite recognition and uptake. In this review, we discuss glycosaminoglycans in the context of Leishmania infection as well as the possible applications of the current knowledge regarding these molecules for the development of new therapeutic strategies to control parasite dissemination.

S1752 Amelioration of TNBS-Induced Colitis By Marine Glycosaminoglycans

delivery of IL-22BP gene was performed into the proximal colon of DSS-treated WT mice. As predicted, significantly enhanced IL-22BP expression was observed in the injected site. The IL-22BP-gene delivery significantly inhibited the activation of STAT3 in CECs within the injected, but not non-injected, sites of the colon. Most importantly, the IL-22BP gene delivery exacerbated the inflammation as judged by presence of severe ulcerations.CONCLUSION: We herein develop a novel microinjection-based local gene delivery system that is capable of targeting inflamed mucosa and may provide a means to develop a new therapeutic strategy for treating mucosal inflammation.