Mesalazine treatment in organotypic culture of celiac patients: Comparative study with gluten free diet.

Given the central role of gluten in the pathogenesis of celiac disease (CD), a strict gluten-free diet (GFD) is the only validated treatment able to restore epithelium integrity and eliminate risks of complications. The risk of gluten contamination and the persistence of inflammation, even in patients strictly adhering to GFD, may render this treatment not always effective claiming the necessity of different new solutions. Oxidative and nitrosative stress have been indicated to play a pathophysiological role in CD. Mesalazine (5-ASA), a drug largely used in inflammatory bowel disease, has potent antinflammatory and antioxidant effects. In fact, mesalazine has been shown to decrease in vitro gluten induced cytokine response and it has been used in vivo in some refractory condition. However, its effect has never compared to that of GFD. The present study aimed to address this issue by comparing the ability of mesalazine and GFD in treating gluten-induced inflammation and oxidative stress. These effects were studied on duodenal mucosa biopsy cultures from newly diagnosed CD patients, treated or not in vitro with mesalazine, and CD biopsy cultures from patients on gluten-free diet for at least one year; and a cohort of controls constituted by healty subjects. On these models, the antioxidant cellular defences, the PPARγ, NF-kB and NOS2 proteins levels were studied. This study shows that mesalazine is as effective as GFD in reducing oxidative burst and inducing PPARγ expression; moreover it resulted more effective than GFD in decreasing NF-kB and NOS2 to the levels of controls.

PPARß/δ and γ in a rat model of Parkinson's disease: possible involvement in PD symptoms.

Parkinson's disease is one of the most common neurologic disorder, affecting about 1-4% of persons older than 60 years. Among the proposed mechanisms of PD generation, free radical damage is believed to play a pivotal role in the development and/or progression of the disease. Recently, PPARs, a class of transcription factors involved in several pathways both in physiological and pathological conditions, have been linked by us and others to neurodegeneration. Particularly, PPARγ and its ligands have been indicated as potential therapeutic targets for the treatment of several pathological conditions associated with neuroinflammation within the CNS. The anti-inflammatory function of PPARγ has attracted attention since agonists exert a broad spectrum of protective effects in several animal models of neurological diseases, including psychiatric diseases. On the other hand a detrimental role for PPARß/δ has been proposed in Alzheimer, being closely related to the decrease of BDNF and Trkfl. On these bases, in this work we used a 6-OHDA hemi-lesioned rat model, inducing loss of dopaminergic neurons, to study the effects of the lesion at three time points from the lesion (1, 2, and 3 weeks), in relevant areas of PD motor symptoms, such as substantia nigra and globus pallidus and in the area of reward and mood control, the nucleus accumbens. In particular, it was studied: (i) the expression of BDNF and its downstream signals; (ii) the modulation of PPARs levels. The results obtained indicate the possible use of a dual PPARß/δ antagonist/PPARγ agonist to counteract primary and secondary signs of PD neurodegeneration.

Glioblastoma Stem Cells Microenvironment: The Paracrine Roles of the Niche in Drug and Radioresistance.

Among all solid tumors, the high-grade glioma appears to be the most vascularized one. In fact, "microvascular hyperplasia" is a hallmark of GBM. An altered vascular network determines irregular blood flow, so that tumor cells spread rapidly beyond the diffusion distance of oxygen in the tissue, with the consequent formation of hypoxic or anoxic areas, where the bulk of glioblastoma stem cells (GSCs) reside. The response to this event is the induction of angiogenesis, a process mediated by hypoxia inducible factors. However, this new capillary network is not efficient in maintaining a proper oxygen supply to the tumor mass, thereby causing an oxygen gradient within the neoplastic zone. This microenvironment helps GSCs to remain in a "quiescent" state preserving their potential to proliferate and differentiate, thus protecting them by the effects of chemo- and radiotherapy. Recent evidences suggest that responses of glioblastoma to standard therapies are determined by the microenvironment of the niche, where the GSCs reside, allowing a variety of mechanisms that contribute to the chemo- and radioresistance, by preserving GSCs. It is, therefore, crucial to investigate the components/factors of the niche in order to formulate new adjuvant therapies rendering more efficiently the gold standard therapies for this neoplasm.

Targeting CXCR1 on breast cancer stem cells: signaling pathways and clinical application modelling.

In breast cancer it has been proposed that the presence of cancer stem cells may drive tumor initiation, progression and recurrences. IL-8, up-regulated in breast cancer, and associated with poor prognosis, increases CSC self-renewal in cell line models. It signals via two cell surface receptors, CXCR1 and CXCR2. Recently, the IL-8/CXCR1 axis was proposed as an attractive pathway for the design of specific therapies against breast cancer stem cells. Reparixin, a powerful CXCR1 inhibitor, was effective in reducing in vivo the tumour-initiating population in several NOD/SCID mice breast cancer models, showing that the selective targeting of CXCR1 and the combination of reparixin and docetaxel resulted in a concomitant reduction of the bulk tumour mass and CSC population. The available data indicate that IL-8, expressed by tumour cells and induced by chemotherapeutic treatment, is a key regulator of the survival and self-renewal of the population of CXCR1-expressing CSC. Consequently, this investigation on the mechanism of action of the reparixin/paclitaxel combination, was based on the observation that reparixin treatment contained the formation of metastases in several experimental models. However, specific data on the formation of breast cancer brain metastases, which carry remarkable morbidity and mortality to a substantial proportion of advanced breast cancer patients, have not been generated. The obtained data indicate a beneficial use of the drug combination reparixin and paclitaxel to counteract brain tumour metastasis due to CSC, probably due to the combined effects of the two drugs, the pro-apoptotic action of paclitaxel and the cytostatic and anti-migratory effects of reparixin.

Involvement of peroxisome proliferator-activated receptor ß/δ (PPAR ß/δ) in BDNF signaling during aging and in Alzheimer disease: possible role of 4-hydroxynonenal (4-HNE).

Aging and many neurological disorders, such as AD, are linked to oxidative stress, which is considered the common effector of the cascade of degenerative events. In this phenomenon, reactive oxygen species play a fundamental role in the oxidative decomposition of polyunsaturated fatty acids, resulting in the formation of a complex mixture of aldehydic end products, such as malondialdehyde, 4-hydroxynonenal, and other alkenals. Interestingly, 4-HNE has been indicated as an intracellular agonist of peroxisome proliferator-activated receptor ß/δ. In this study, we examined, at early and advanced AD stages (3, 9, and 18 months), the pattern of 4-HNE and its catabolic enzyme glutathione S-transferase P1 in relation to the expression of PPARß/δ, BDNF signaling, as mRNA and protein, as well as on their pathological forms (i.e., precursors or truncated forms). The data obtained indicate a novel detrimental age-dependent role of PPAR ß/δ in AD by increasing pro-BDNF and decreasing BDNF/TrkB survival pathways, thus pointing toward the possibility that a specific PPARß/δ antagonist may be used to counteract the disease progression.