Dysfunction of the Brown Adipose Organ in HFD-Obese Rats and Effect of Tart Cherry Supplementation.

Obesity has a great impact on adipose tissue biology, based on its function as a master regulator of energy balance. Brown adipose tissue (BAT) undergoes remodeling, and its activity declines in obese subjects due to a whitening process. The anti-obesity properties of fruit extracts have been reported. The effects of tart cherry against oxidative stress, inflammation, and the whitening process in the BAT of obese rats were investigated. Intrascapular BAT (iBAT) alterations and effects of Prunus cerasus L. were debated in rats fed for 17 weeks with a high-fat diet (DIO), in DIO supplemented with seed powder (DS), and with seed powder plus the juice (DJS) of tart cherry compared to CHOW rats fed with a normo-caloric diet. iBAT histologic observations revealed a whitening process in DIO rats that was reduced in the DS and DJS groups. A modulation of uncoupling protein-1 (UCP-1) protein and gene expression specifically were detected in the obese phenotype. An upregulation of UCP-1 and related thermogenic genes after tart cherry intake was detected compared to the DIO group. Metabolic adjustment, endoplasmic reticulum stress, protein carbonylation, and the inflammatory microenvironment in the iBAT were reported in DIO rats. The analysis demonstrated an iBAT modulation that tart cherry promoted. In addition to our previous results, these data confirm the protective impact of tart cherry consumption on obesity.

Supplementation with Lactiplantibacillus plantarum IMC 510 Modifies Microbiota Composition and Prevents Body Weight Gain Induced by Cafeteria Diet in Rats.

Changes in functionality and composition of gut microbiota (GM) have been associated and may contribute to the development and maintenance of obesity and related diseases. The aim of our study was to investigate for the first time the impact of Lactiplantibacillus (L.) plantarum IMC 510 in a rat model of diet-induced obesity, specifically in the cafeteria (CAF) diet. This diet provides a strong motivation to voluntary overeat, due to the palatability and variety of selected energy-dense foods. The oral administration for 84 days of this probiotic strain, added to the CAF diet, decreased food intake and body weight gain. Accordingly, it ameliorated body mass index, liver and white adipose tissue weight, hepatic lipid accumulation, adipocyte size, serum parameters, including glycemia and low-density lipoprotein levels, in CAF fed rats, potentially through leptin control. In this scenario, L. plantarum IMC 510 showed also beneficial effects on GM, limiting the microbial imbalance established by long exposure to CAF diet and preserving the proportion of different bacterial taxa. Further research is necessary to better elucidate the relationship between GM and overweight and then the mechanism of action by which L. plantarum IMC 510 modifies weight. However, these promising results prompt a clear advantage of probiotic supplementation and identify a new potential probiotic as a novel and safe therapeutic approach in obesity prevention and management.

Tart Cherry Juice and Seeds Affect Pro-Inflammatory Markers in Visceral Adipose Tissue of High-Fat Diet Obese Rats.

BACKGROUND: Tart cherries (Prunus cerasus L.) are a rich source of anthocyanins. They are phytochemical flavonoids found in red and blue fruits, and vegetables that can reduce hyperlipidemia. Visceral Adipose Tissue (VAT) has emerged as a major player in driving obesity-related inflammatory response. METHODS: This study has investigated the potential positive effects of tart cherries on rats with Diet-Induced Obesity (DIO). In particular, the inflammatory status in retroperitoneal (RPW) and perigonadal (PGW) adipose tissue were studied. Rats were fed ad libitum for 17 weeks with a hypercaloric diet with the supplementation of tart cherries seeds powder (DS) and seeds powder plus tart cherries juice containing 1mg of anthocyanins (DJS). In RPW and PGW, expression of CRP, IL-1 ß, TNF-α, CCL2 and CD36, were measured by qRT-PCR, Western blot and immunohistochemistry techniques. RESULTS: No differences in the weight of RPW and PGW animals were found between DS and DJS groups compared to DIO rats. However, an increase of inflammatory markers was observed in DIO group in comparison with control lean rats. A modulation of these markers was evident upon tart cherry supplementation. CONCLUSION: Study results suggest that tart cherry enriched-diet did not modify the accumulation of visceral fat, but it decreased inflammatory markers in both tissues. Therefore, this supplementation could be useful, in combination with healthy lifestyles, to modify adipose tissue cell metabolism limiting-obesity related organ damage.

Effects of Prunus cerasus L. Seeds and Juice on Liver Steatosis in an Animal Model of Diet-Induced Obesity.

The accumulation of adipose tissue increases the risk of several diseases. The fruits-intake, containing phytochemicals, is inversely correlated with their development. This study evaluated the effects of anthocyanin-rich tart cherries in diet-induced obese (DIO) rats. DIO rats were exposed to a high-fat diet with the supplementation of tart cherry seeds powder (DS) and seed powder plus juice (DJS). After 17 weeks, the DIO rats showed an increase of body weight, glycaemia, insulin, and systolic blood pressure. In the DS and DJS groups, there was a decrease of systolic blood pressure, glycaemia, triglycerides, and thiobarbituric reactive substances in the serum. In the DJS rats, computed tomography revealed a decrease in the spleen-to-liver attenuation ratio. Indeed, sections of the DIO rats presented hepatic injury characterized by steatosis, which was lower in the supplemented groups. In the liver of the DIO compared with rats fed with a standard diet (CHOW), a down-regulation of the GRP94 protein expression and a reduction of LC3- II/LC3-I ratio were found, indicating endoplasmic reticulum stress and impaired autophagy flux. Interestingly, tart cherry supplementation enhanced both unfolded protein response (UPR) and autophagy. This study suggests that tart cherry supplementation, although it did not reduce body weight in the DIO rats, prevented its related risk factors and liver steatosis.

Starch-enriched diet modulates the glucidic profile in the rat colonic mucosa.

PURPOSE: The protective function of the intestinal mucosa largely depends on carbohydrate moieties that as a part of glycoproteins and glycolipids form the epithelial glycocalyx or are secreted as mucins. Modifications of their expression can be induced by an altered intestinal microenvironment and have been associated with inflammatory disorders and colorectal cancer. Given the influence of dietary factors on the gut ecosystem, here we have investigated whether a long term feeding on a starch-rich diet can modulate the glucidic profile in the colonic mucosa of rats. METHODS: Animals were divided into two groups and maintained for 9 months at different diets: one group was fed a standard diet, the second was fed a starch-enriched diet. Samples of colonic mucosa, divided in proximal and distal portions, were processed for microscopic analysis. Conventional stainings and lectin histochemistry were applied to identify acidic glycoconjugates and specific sugar residues in oligosaccharide chains, respectively. Some lectins were applied on adjacent sections after sialidase/fucosidase digestion, deacetylation, and oxidation to characterize either terminal dimers or sialic acid acetylation. RESULTS: An increase in sulfomucins was found to be associated with the starch-enriched diet that affected also the expression of several sugar residues as well as fucosylated and sialylated sequences in both proximal and distal colon. CONCLUSIONS: Although the mechanisms leading to such a modulation are at present unknown, either an altered intestinal microbiota or a dysregulation of glycosylation patterns might be responsible for the types and distribution of changes in the glucidic profile here observed.

A Wickerhamomyces anomalus killer strain in the malaria vector Anopheles stephensi.

The yeast Wickerhamomyces anomalus has been investigated for several years for its wide biotechnological potential, especially for applications in the food industry. Specifically, the antimicrobial activity of this yeast, associated with the production of Killer Toxins (KTs), has attracted a great deal of attention. The strains of W. anomalus able to produce KTs, called "killer" yeasts, have been shown to be highly competitive in the environment. Different W. anomalus strains have been isolated from diverse habitats and recently even from insects. In the malaria mosquito vector Anopheles stephensi these yeasts have been detected in the midgut and gonads. Here we show that the strain of W. anomalus isolated from An. stephensi, namely WaF17.12, is a killer yeast able to produce a KT in a cell-free medium (in vitro) as well as in the mosquito body (in vivo). We showed a constant production of WaF17.12-KT over time, after stimulation of toxin secretion in yeast cultures and reintroduction of the activated cells into the mosquito through the diet. Furthermore, the antimicrobial activity of WaF17.12-KT has been demonstrated in vitro against sensitive microbes, showing that strain WaF17.12 releases a functional toxin. The mosquito-associated yeast WaF17.12 thus possesses an antimicrobial activity, which makes this yeast worthy of further investigations, in view of its potential as an agent for the symbiotic control of malaria.

Carbonic anhydrase in minor salivary glands of quail: histochemistry versus immunohistochemistry.

Studies on the mechanisms of saliva secretion have indicated that carbonic anhydrase (CA) is expressed in mammalian salivary glands. The enzyme is present in the saliva as the only known secretory isoenzyme, CAVI; its activity has been related to the modulation of taste and caries development. Unlike mammals, in birds, saliva is produced by the so-called minor salivary glands, mostly concentrated in the tongue. The involvement of CA has never been explored in avian salivary secretion. Thus, we aimed here to ascertain the enzyme occurrence in the quail lingual glands by a parallel investigation of the distributional patterns of CA activity sites, as visualized by histochemistry, and the immunohistochemical patterns of cytosolic CAII and secretory CAVI. The comparative evaluation of our findings does not rule out that some CA isoforms, associated to basolateral borders of the secretory cells and antigenically different from cytosolic CAII and secretory CAVI, may be involved in the salivary secretion in the quail lingual glands.

Astrogliosis in the brain of obese Zucker rat: a model of metabolic syndrome.

Metabolic syndrome (MetS) is a disorder characterized primarily by the development of insulin resistance. Insulin resistance and subsequent hyperinsulinemia, originating from abdominal obesity, increases the risk of cerebrovascular and cardiovascular disease and all-cause mortality. Obesity is probably a risk factor for Alzheimer's disease and vascular dementia and is associated with impaired cognitive function. The obese Zucker rat (OZR) represents a model of type 2 diabetes exhibiting a moderate degree of arterial hypertension and of increased oxidative stress. To clarify the possible relationships between MetS and brain damage, the present study has investigated brain microanatomy in OZRs compared with their littermate controls lean Zucker rats (LZRs). Male OZRs and LZRs of 12 weeks of age were used. Their brain was processed for immunochemical and immunohistochemical analysis of glial fibrillary acidic protein (GFAP). In frontal and parietal cortex of OZRs a significant increase in the number of GFAP immunoreactive astrocytes was observed. Similar findings were found in the hippocampus, where an increased number of GFAP immunoreactive astrocytes were detected in the CA1 and CA3 subfields and dentate gyrus of OZRs compared to the LZRs. These findings indicating the occurrence of brain injury accompanied by astrogliosis in OZRs suggest that these rats, developed as an animal model of type 2 diabetes, may also represent a model for assessing the influence of MetS on brain. The identification of neurodegenerative changes in OZRs may represent the first step for better characterizing neuronal involvement in this model of MetS and possible treatment for countering it.

The chick chorioallantoic membrane: a model of molecular, structural, and functional adaptation to transepithelial ion transport and barrier function during embryonic development.

The chick chorioallantoic membrane is a very simple extraembryonic membrane which serves multiple functions during embryo development; it is the site of exchange of respiratory gases, calcium transport from the eggshell, acid-base homeostasis in the embryo, and ion and H(2)O reabsorption from the allantoic fluid. All these functions are accomplished by its epithelia, the chorionic and the allantoic epithelium, by differentiation of a wide range of structural and molecular peculiarities which make them highly specialized, ion transporting epithelia. Studying the different aspects of such a developmental strategy emphasizes the functional potential of the epithelium and offers an excellent model system to gain insights into questions partly still unresolved.

Lectin histochemistry for in situ profiling of rat colon sialoglycoconjugates.

The growing interest in glycoconjugates expressed and released by the epithelium of the intestinal mucosa is tightly related to the multiple functional roles attributed to sialic acid and its derivatives. In the present work, biotin and HRP conjugated lectins were used to detect the sialylation pattern and to identify specific structural features of sialoderivatives in the rat colon. In particular, the occurrence and distribution of sialic acids linked alpha2,6 to D-Gal/D-GalNAc and alpha2,3 to D-Gal were directly demonstrated with SNA and MAL II binding, respectively. In addition, in order to by-pass the specificity problems of SNA and MAL II as histochemical reagents, as well as to look for additional and complementary information about acetylation degree and sites, we combined sialidase digestion, potassium hydroxide deacetylation, and differential periodate oxidation with PNA and DBA binding. The data showed the distribution and structure of sialic acid-beta-D-Gal(1-3)-D-GalNAc and sialic acid-D-GalNac sequences, which proved to be widely distributed as cellular components or secretory products in surface goblet cells and crypt cells of the colonic epithelium. A high degree of O-acetylation, with acetyl groups mainly at 9 and 4 positions, was found, showing an increasing gradient from the proximal to distal portion of the colon. These results, which largely reproduce the sialylation pattern in other species, contribute new insights in defining the tissue specific expression of sialoderivatives in the colonic mucosa, and testify to their high heterogeneity which the wide range of sialic acid functional correlates in the intestinal tract depend on.

Prostaglandins differently regulate FGF-2 and FGF receptor expression and induce nuclear translocation in osteoblasts via MAPK kinase.

We have previously reported that prostaglandin F(2alpha) (PGF(2alpha)) and its selective agonist fluprostenol increase basic fibroblast growth factor (FGF-2) mRNA and protein production in osteoblastic Py1a cells. The present report extends our previous studies by showing that Py1a cells express FGF receptor-2 (FGFR2) and that treatment with PGF(2alpha) or fluprostenol decreases FGFR2 mRNA. We have used confocal and electron microscopy to show that, under PGF(2alpha) stimulation, FGF-2 and FGFR2 proteins accumulate near the nuclear envelope and colocalize in the nucleus of Py1a cells. Pre-treatment with cycloheximide blocks nuclear labelling for FGF-2 in response to PGF(2alpha). Treatment with SU5402 does not block prostaglandin-mediated nuclear internalization of FGF-2 or FGFR2. Various effectors have been used to investigate the signal transduction pathway. In particular, pre-treatment with phorbol 12-myristate 13-acetate (PMA) prevents the nuclear accumulation of FGF-2 and FGFR2 in response to PGF(2alpha). Similar results are obtained by pre-treatment with the protein kinase C (PKC) inhibitor H-7. In addition, cells treated with PGF(2alpha) exhibit increased nuclear labelling for the mitogen-activated protein kinase (MAPK), p44/ERK2. Pre-treatment with PMA blocks prostaglandin-induced ERK2 nuclear labelling, as confirmed by Western blot analysis. We conclude that PGF(2alpha) stimulates nuclear translocation of FGF-2 and FGFR2 by a PKC-dependent pathway; we also suggest an involvement of MAPK/ERK2 in this process.

Developmental expression of glycocomponents in the chick chorioallantoic membrane.

Widespread interest has focused on the research of the chorioallantoic membrane (CAM) and its functional contribution to gaseous exchange, calcium reabsorption, water and electrolyte transport during chick embryogenesis. Nevertheless, very little information is available on the glycoconjugate components of this extra-embryonic structure. In the present study, we investigated by lectin histochemistry, the glycosylation pattern expressed in the CAM epithelia during embryonic development. Occurrence of sialic acid-associated glycoproteins was detailed by either specific lectins, which discriminate alpha2,3 and alpha2,6 sialoderivatives, or sialidase digestion combined with appropriate lectins to identify the sialic acid acceptor sugars. Lectin affinities proved to depend greatly on differentiation of the CAM epithelia which showed highest expression of binding sites during the second half of incubation up to hatching. Differences emerged between the chorionic and the allantoic epithelium, regarding qualitative, quantitative and temporal expression of sugar moieties. A cell type-specific distribution of glycocomponents was found in the chorionic epithelium where lectin binding sites were specifically located in the villus cavity cells. In the allantoic epithelium, high and heterogeneous occurrence of sialoglycoconjugates as well as specific presence of fucose residues were evidenced mostly in the granule cells. We conclude from these findings that various glycoconjugates in the CAM could participate in different physiological functions characteristic of the chorionic and the allantoic epithelium.