Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance.

TP63, an important epithelial developmental gene, has significant homology to p53. Unlike p53, the expression of p63 is regulated by two different promoters resulting in proteins with opposite functions: the full-length transcriptionally active TAp63 and the dominant-negative DNp63. We investigated the downstream mechanisms by which TAp63a elicits apoptosis. TAp63a directly transactivates the CD95 gene via the p53 binding site in the first intron resulting in upregulation of a functional CD95 death receptor. Stimulation and blocking experiments of the CD95, TNF-R and TRAIL-R death receptor systems revealed that TAp63a can trigger expression of each of these death receptors. Furthermore, our findings demonstrate a link between TAp63a and the mitochondrial apoptosis pathway. TAp63a upregulates expression of proapoptotic Bcl-2 family members like Bax and BCL2L11 and the expression of RAD9, DAP3 and APAF1. Of clinical relevance is the fact that TAp63a is induced by many chemotherapeutic drugs and that inhibiting TAp63 function leads to chemoresistance. Thus, beyond its importance in development and differentiation, we describe an important role for TAp63a in the induction of apoptosis and chemosensitivity.

Vitamin C is accumulated in mammalian cells by two types of proteins: sodium-ascorbate co-transporters (SVCTs) and hexose transporters (GLUTs); in particular, SVCTs actively import ascorbate, the reduced form of this vitamin. SVCTs are surface glycoproteins encoded by two different genes, very similar in structure. They show distinct tissue distribution and functional characteristics, which indicate different physiological roles. SVCT1 is involved in whole-body homeostasis of vitamin C, while SVCT2 protects metabolically active cells against oxidative stress. Regulation at mRNA or protein level may serve for preferential accumulation of ascorbic acid at sites where it is needed. This review will summarize the present knowledge on structure, function and regulation of the SVCT transporters. Understanding the physiological role of SVCT1 and SVCT2 may lead to develop new therapeutic strategies to control intracellular vitamin C content or to promote tissue-specific delivery of vitamin C-drug conjugates.

Epidermal development requires the transcription factor p63, as p63À/À mice are born dead, without skin. The gene expresses two proteins, one with an amino-terminal transactivation domain (TAp63) and one without (DNp63), although their relative contribution to epidermal development is unknown. To address this issue, we reintroduced TAp63a and/or DNp63a under the K5 promoter into p63À/À mice by in vivo genetic complementation. Whereas p63À/À and p63À/À;TA mice showed extremely rare patches of poorly differentiated keratinocytes, p63À/À;DN mice showed significant epidermal basal layer formation. Double TAp63a/ DNp63a complementation showed greater patches of differentiated skin; at the ultrastructural level, there was clear reformation of a distinct basal membrane and hemidesmosomes. At the molecular level, DNp63 regulated expression of genes characteristic of the basal layer (K14), interacting (by Chip, luc assay) with the third p53 consensus site. Conversely, TAp63 transcribed the upper layer's genes (Ets-1, K1, transglutaminases, involucrin). Therefore, the two p63 isoforms appear to play distinct cooperative roles in epidermal formation.

Breast cancer (BC) is the second most common cancer worldwide and the most commonly occurring malignancy in women. There is growing evidence that lifestyle factors, including diet, body weight and physical activity, may be associated with higher BC risk. However, the effect of dietary factors on BC recurrence and mortality is not clearly understood. Here, we provide an overview of the current evidence obtained from the PubMed databases in the last decade, assessing dietary patterns, as well as the consumption of specific food-stuffs/food-nutrients, in relation to BC incidence, recurrence and survival. Data from the published literature suggest that a healthy dietary pattern characterized by high intake of unrefined cereals, vegetables, fruit, nuts and olive oil, and a moderate/low consumption of saturated fatty acids and red meat, might improve overall survival after diagnosis of BC. BC patients undergoing chemotherapy and/or radiotherapy experience a variety of symptoms that worsen patient quality of life. Studies investigating nutritional interventions during BC treatment have shown that nutritional counselling and supplementation with some dietary constituents, such as EPA and/or DHA, might be useful in limiting drug-induced side effects, as well as in enhancing therapeutic efficacy. Therefore, nutritional intervention in BC patients may be considered an integral part of the multimodal therapeutic approach. However, further research utilizing dietary interventions in large clinical trials is required to definitively establish effective interventions in these patients, to improve long-term survival and quality of life.

The p53-related p73 and p63 genes encode proteins that share considerable structural and functional homology with p53. Despite similarities, their deletion in mice has different outcomes, implying that the three genes may play distinct roles in vivo. Here we show that endogenous p73 levels increase in neuroblastoma cells induced to differentiate by retinoic acid and that exogenously expressed p73, but not p53, is sufficient to induce both morphological (neurite outgrowth) and biochemical (expression of neurofilaments and neural cell adhesion molecule (N-CAM); down-regulation of N-MYC and up-regulation of pRB) markers of neuronal differentiation. This activity is shared, to different extents, by all p73 isoforms, whereas the transcriptionally inactive mutants of p73 isoforms are ineffective. Conversely, blockage of endogenous p73 isoforms with a dominant negative p73 results in the abrogation of retinoid-induced N-CAM promoter-driven transcription. Our results indicate that the p73 isoforms activate a pathway that is not shared by p53 and that is required for neuroblastoma cell differentiation in vitro.The p53 homologue p73 (1) is expressed in human cells as several alternatively spliced forms that show different abilities to homo/heterodimerize with each other and with p53 (1-3). Few studies have directly investigated p73 functions, and its assumed activities are largely based on analogy with its p53 homologue. Indeed, p73 isoforms share with p53 the ability to transactivate the p21 promoter, thus enforcing cell cycle arrest at the G 1 /S transition (1, 2, 4), and to induce apoptosis when overexpressed (4). p73 apoptotic functions are also recruited in response to DNA damage, through a p53-independent pathway that requires the activation of the nuclear tyrosine kinase c-Abl by either ATM or a proficient MLH-1 mismatch repair gene (5-7). Unlike p53, mutant p73 genes have rarely been found in human tumors (8 -10). There is evidence that p73 may play a role in differentiation. The carboxyl terminus of both p63 and p73 contains a sterile ␣ motif found in a variety of signaling proteins that is known to play a role in development and differentiation (11). The p73 gene has been mapped to a region (1p36.33) that is frequently deleted in neuroblastomas (undifferentiated neuronal tumors (12, 13)), suggesting that loss or altered expression of p73 in vivo may be a determinant of the undifferentiated phenotype of neuroblastoma. Moreover, neurons from p53 null mice and neurons from wild type mice cultured with p53 antisense oligonucleotides in vitro show accelerated spontaneous differentiation (14). This suggests the hypothesis that loss of the p53 heterodimeric partner of p73 may liberate more uncomplexed or homodimerized p73 and allow expression of its differentiation-inducing function.Accordingly, we have investigated the role of p73 in the differentiation of neuroblastoma cell lines, a well studied model of neuronal differentiation and death (15-17). MATERIALS AND METHODSCell Culture-N1E-115 cells were grown in Dulbecco...

Endocannabinoids bind to cannabinoid, vanilloid, and peroxisome proliferator-activated receptors. The biological actions of these polyunsaturated lipids are controlled by key agents responsible for their synthesis, transport and degradation, which together form an endocannabinoid system (ECS). In the past few years, evidence has been accumulated for a role of the ECS in regulating food intake and energy balance, both centrally and peripherally. In addition, up-regulation of the ECS in the gastrointestinal tract has a potential impact on inflammatory bowel diseases. In this review, the main features of the ECS are summarized in order to put in better focus our current knowledge of the nutritional relevance of endocannabinoid signaling and of its role in obesity, cardiovascular pathologies, and gastrointestinal diseases. The central and peripheral pathways that underlie these effects are discussed, as well as the possible exploitation of ECS components as novel drug targets for therapeutic intervention in eating disorders.

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