Aging-Related Expression of Twinfilin-1 Regulates Cholangiocyte Biological Response to Injury.

Disorders of the biliary tree develop and progress differently according to patient age. It is currently not known whether the aging process affects the response to injury of cholangiocytes. The aim of this study was to identify molecular pathways associated with cholangiocyte aging and to determine their effects in the biological response to injury of biliary cells. A panel of microRNAs (miRs) involved in aging processes was evaluated in cholangiocytes of young and old mice (2 months and 22 months of age, respectively) and subjected to a model of sclerosing cholangitis. Intracellular pathways that are common to elevated miRs were identified by in silico analysis. Cell proliferation and senescence were evaluated in Twinfilin-1 (Twf1) knocked-down cells. In vivo, senescence-accelerated prone mice (Samp8, a model for accelerated aging), Twf1-/- , or their respective controls were subjected to DDC (3,5-diethoxycarbonyl-1,4-dihydrocollidine). Cholangiocytes from DDC-treated mice showed up-regulation of a panel of aging-related miRs. Twf1 was identified by in silico analysis as a common target of the up-regulated miRs. Twf1 expression was increased both in aged and diseased cholangiocytes, and in human cholangiopathies. Knock-down of Twf1 in cholangiocytes reduced cell proliferation. Senescence and senescence-associated secretory phenotype marker expression increased in Twf1 knocked-down cholangiocytes following pro-proliferative and pro-senescent (10-day lipopolysaccharide) stimulation. In vivo, Samp8 mice showed increased biliary proliferation, fibrosis, and Twf1 protein expression level, whereas Twf1-/- had a tendency toward lower biliary proliferation and fibrosis following DDC administration compared with control animals. Conclusion: We identified Twf1 as an important mediator of both cholangiocyte adaptation to aging processes and response to injury. Our data suggest that disease and aging might share common intracellular pathways.

HDL cholesterol protects from liver injury in mice with intestinal specific LXRα activation.

BACKGROUND AND AIMS: Liver X receptors (LXRs) exert anti-inflammatory effects even though their hepatic activation is associated with hypertriglyceridemia and hepatic steatosis. Selective induction of LXRs in the gut might provide protective signal(s) in the aberrant wound healing response that induces fibrosis during chronic liver injury, without hypertriglyceridemic and steatogenic effects. METHODS: Mice with intestinal constitutive LXRα activation (iVP16-LXRα) were exposed to intraperitoneal injection of carbon tetrachloride (CCl4 ) for 8 weeks, and in vitro cell models were used to evaluate the beneficial effect of high-density lipoproteins (HDL). RESULTS: After CCl4 treatment, the iVP16-LXRα phenotype showed reduced M1 macrophage infiltration, increased expression M2 macrophage markers, and lower expression of hepatic pro-inflammatory genes. This anti-inflammatory effect in the liver was also associated with decreased expression of hepatic oxidative stress genes and reduced expression of fibrosis markers. iVP16-LXRα exhibited increased reverse cholesterol transport in the gut by ABCA1 expression and consequent enhancement of the levels of circulating HDL and their receptor SRB1 in the liver. No hepatic steatosis development was observed in iVP16-LXRα. In vitro, HDL induced a shift from M1 to M2 phenotype of LPS-stimulated Kupffer cells, decreased TNFα-induced oxidative stress in hepatocytes and reduced NF-kB activity in both cells. SRB1 silencing reduced TNFα gene expression in LPS-stimulated KCs, and NOX-1 and IL-6 in HepG2. CONCLUSIONS: Intestinal activation of LXRα modulates hepatic response to injury by increasing circulating HDL levels and SRB1 expression in the liver, thus suggesting this circuit as potential actionable pathway for therapy.

The Bio-Functional Properties of Pigmented Cereals may Involve Synergies among Different Bioactive Species.

This study was aimed at characterizing the anthocyanins and phenolics profile in different varieties of pigmented corn and wheat and in some of their milling fractions. Acid/ethanol extracts were used to assess total anthocyanins, overall antioxidant activity, the overall polyphenol profile, and for evaluating the inhibition of pancreatic α-amylase and of intestinal α-glucosidase. Both enzymes were inhibited in a dose-dependent manner by all extracts, but individual extracts had specific effects on each enzyme. Anti-inflammatory response was evaluated by using acid-free extracts and Caco-2 cells transiently transfected with a luciferase reporter gene responding to cytokine stimulation. The immune response of interleukin-stimulated cells decreased significantly in a dose-dependent manner in the presence of 20-50 µM/l anthocyanins from all grains extracts, again with a different efficiency. The inhibitory ability and the anti-inflammatory capability of these extracts are in most cases higher than in similar extracts from other sources, suggesting that activities in each extract may imply specific synergies between anthocyanins and other phenolics.

Role of inflammation and proinflammatory cytokines in cholangiocyte pathophysiology.

Cholangiocytes, the epithelial cells lining the bile ducts, are an important subset of liver cells. They are involved in the modification of bile volume and composition, and respond to endogenous and exogenous stimuli. Along the biliary tree, two different kinds of cholangiocytes exist: small and large cholangiocytes. Each type has different features and biological role in physiologic and pathologic conditions, and their immunobiology is important for understanding biliary diseases. Cholangiocytes provide the first line of defence against luminal microbes in the hepatobiliary system. Indeed, they express a variety of pattern recognition receptors and may start an antimicrobial defence activating a set of intracellular signalling cascades. In response to injury, cholangiocytes that are normally quiescent become reactive and acquire a neuroendocrine-like phenotype with the release of proinflammatory mediators and antimicrobial peptides, which support biliary epithelial integrity. These molecules act in an autocrine/paracrine manner to modulate cholangiocyte biology and determine the evolution of biliary damage. Failure or dysregulation of such mechanisms may influence the progression of cholangiopathies, a group of diseases that selectively target biliary cells. In this review, we focus on the response of cholangiocytes in inflammatory conditions, with a particular focus on the mechanism driving cholangiocytes adaptation to damage. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by Jesus Banales, Marco Marzioni, Nicholas LaRusso and Peter Jansen.

Nlrp3 Activation Induces Il-18 Synthesis and Affects the Epithelial Barrier Function in Reactive Cholangiocytes.

Microbial products are thought to influence the progression of cholangiopathies, in particular primary sclerosing cholangitis (PSC). Inflammasomes are molecular platforms that respond to microbial products through the synthesis of proinflammatory cytokines. We investigated the role of inflammasome activation in cholangiocyte response to injury. Nucleotide-binding oligomerization domain (NOD)-like receptor family, pyrin domain-containing protein 3 (Nlrp3) expression was tested in cholangiocytes of normal and cholestatic livers. Effects of Nlrp3 activation induced by incubation with lipopolysaccharide and ATP was studied in vitro in normal and siRNA-Nlrp3 knocked-down cholangiocytes. Wild-type and Nlrp3 knockout (Nlrp3-/-) mice were fed 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC; a model of sclerosing cholangitis) for 4 weeks. Nlrp3 and its components were overexpressed in cholangiocytes of mice subjected to DDC and in patients affected by PSC. In vitro, Nlrp3 activation stimulated expression of Il-18 but not of Il-1ß and Il-6. Nlrp3 activation had no effect on cholangiocyte proliferation but significantly decreased the expression of Zonulin-1 and E-cadherin, whereas Nlrp3 knockdown increased the permeability of cholangiocyte monolayers. In vivo, the DDC-stimulated number of cytokeratin-19-positive cells in the liver of wild-type animals was slightly reduced in Nlrp3-/- mice, and expression of E-cadherin was reestablished. In conclusion, Nlrp3 is expressed in reactive cholangiocytes, in both murine models and patients with PSC. Activation of Nlrp3 leads to synthesis of proinflammatory cytokines and influences epithelial integrity of cholangiocytes.

Inflammation and the Gut-Liver Axis in the Pathophysiology of Cholangiopathies.

Cholangiocytes, the epithelial cells lining the bile ducts, represent the unique target of a group of progressive diseases known as cholangiopathies whose pathogenesis remain largely unknown. In normal conditions, cholangiocytes are quiescent and participate to the final bile volume and composition. Following exogenous or endogenous stimuli, cholangiocytes undergo extensive modifications of their phenotype. Reactive cholangiocytes actively proliferate and release a set of proinflammatory molecules, which act in autocrine/paracrine manner mediating the cross-talk with other liver cell types and innate and adaptive immune cells. Cholangiocytes themselves activate innate immune responses against gut-derived microorganisms or bacterial products that reach the liver via enterohepatic circulation. Gut microbiota has been implicated in the development and progression of the two most common cholangiopathies, i.e., primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), which have distinctive microbiota composition compared to healthy individuals. The impairment of intestinal barrier functions or gut dysbiosis expose cholangiocytes to an increasing amount of microorganisms and may exacerbate inflammatory responses thus leading to fibrotic remodeling of the organ. The present review focuses on the complex interactions between the activation of innate immune responses in reactive cholangiocytes, dysbiosis, and gut permeability to bacterial products in the pathogenesis of PSC and PBC.

Folate distribution in barley (Hordeum vulgare L.), common wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum durum Desf.) pearled fractions.

BACKGROUND: Wholegrain cereals are an important source of folates. In this study, total folate was analysed in pearled fractions of barley and wheat cultivars employing AOAC Official Method 2004.05. In particular, the distribution of folate in the kernels was evaluated in three barley cultivars (two hulled types and a hulless one as well as two- and six-row types) and in a common and a durum wheat cultivar. RESULTS: A noticeable variation in the folate content was observed between the barley [653-1033 ng g(-1) dry matter (DM)] and wheat cultivars (1024-1119 ng g(-1) DM). The highest folate content was detected in the hulless barley cultivar (1033 ng g(-1) DM). A significant reduction in total folate, from 63% to 86%, was observed in all cultivars from the outermost to the innermost pearled fractions. CONCLUSION: Results proved that folates are mainly present in the germ and in the outer layers of the kernel. This is the first study reporting the folate distribution in kernels of both common and durum wheat and in a hulless barley cultivar. Results suggest that the pearling process could be useful for the selection of intermediate fractions that could be used in order to develop folate-enhanced ingredients and products.

Malignant melanoma in a seagull (Larus fuscus): morphological and immunohistochemical approach.

A common seagull (Larus fuscus) was found near the southern coast of Italy by the veterinarians of the local wild animal rescue center. Physical examination of the bird revealed an ulcerated mass involving a majority of the oral cavity; the mass did not allow for normal feeding. After the bird died necropsy was performed and the mass was histologically and immunohistochemically examined. The morphology and the immunoreactivity for Melan-A and S-100 antigens led to a diagnosis of malignant melanoma. This is the first case of malignant melanoma described in a seagull, and herein we compare the characteristics of the present case with malignant melanoma already described in domestic animals.

High-amylose corn in gluten-free pasta: Strategies to deliver nutritional benefits ensuring the overall quality.

High-amylose corn alone or in combination (25% and 50%) with conventional corn was used to produce gluten-free pasta. Flour pre-gelatinization in a tank (process A) or on a conveyor belt (process B) were tested. Resistant starch (RS), soluble (SPAs) and cell-wall bound phenolic acids (CWBPAs) and antioxidant capacity were significantly higher in high-amylose corn pasta. Cooked pasta from process B showed a higher SPA concentration, likely due to the lower cooking loss. The structure of pasta prepared with process B was more homogeneous, whereas it was more compact in the case of process A, as shown by a lower starch susceptibility to α-amylase hydrolysis, higher beginning of gelatinization temperature and lower water absorption. 25% HA represents a good compromise between high RS (4.2%) and good cooking behavior. At higher HA levels, process B is more suitable to obtain pasta with a better cooking quality.

The effect of the amylose content and milling fractions on the physico-chemical features of co-extruded snacks from corn.

The suitability of corn fractions (break meal: 250-500 µm; flour: < 150 µm) from hybrids with different amylose contents (conventional: 18%; high-amylose: 42%; waxy: 2%) and their blends, to produce co-extruded snacks was assessed. Corn flour exhibited a higher content in total soluble phenolic acids (+34%) than break meal. The high-amylose hybrid maintained a higher antioxidant capacity and phenolic acid content (+52% for soluble and + 54% for cell-wall bound phenolic acids), even after extrusion, than the conventional one. Because of its gelatinization properties (high pasting and peak temperatures; low maximum viscosity), the high-amylose hybrid produced co-extruded snacks characterized by low section areas and large inner areas. The blends led to snacks whose features (sections and inner areas, porosity and hardness) did not follow a linear trend with the amylose content, suggesting the need for further studies to better understand the starch interactions that take place among the various hybrids.

Elevated CO2 Impact on Common Wheat (Triticum aestivum L.) Yield, Wholemeal Quality, and Sanitary Risk.

The rising atmospheric CO2, concentration is expected to exert a strong impact on crop production, enhancing crop growth but threatening food security and safety. An improver wheat, a hybrid, and its parents were grown at elevated CO2, e[CO2] in open field, and their yield and rheological, nutritional, and sanitary quality were assessed. For all cultivars, grain yield increased (+16%) and protein content decreased (-7%), accompanied by a reduction in dough strength. Grain nitrogen yield increased (+24%) only in ordinary bread making cultivars. e[CO2] did not result in significant changes in phenolic acid content and composition, whereas it produced a significant increase in the deoxynivalenol content. Different responses to e[CO2] between cultivars were found for yield parameters, while the effect on qualitative traits was quite similar. In the upcoming wheat cropping systems, agronomic practices and cultivar selection suited to guarantee higher nitrogen responsiveness and minimization of sanitary risk are required.

Characterization and selection of functional yeast strains during sourdough fermentation of different cereal wholegrain flours.

The increasing demand for healthy baked goods boosted studies on sourdough microbiota with beneficial metabolic traits, to be used as potential functional starters. Here, 139 yeasts isolated from cereal-based fermented foods were in vitro characterized for their phytase and antioxidant activities. The molecular characterization at strain level of the best 39 performing isolates showed that they did not derive from cross contamination by baker's yeast. Afterwards, the 39 isolates were in vivo analyzed for their leavening ability, phytase activity and polyphenols content using five different wholegrain flours, obtained from conventional and pigmented common wheat, emmer and hull-less barley. Combining these findings, through multivariate permutation analysis, we identified the 2 best performing strains, which resulted diverse for each flour. Doughs singly inoculated with the selected strains were further analyzed for their antioxidant capacity, phenolic acids, xanthophylls and anthocyanins content. All the selected yeasts significantly increased the total antioxidant activity, the soluble, free and conjugated, forms of phenolic acids and anthocyanins of fermented doughs. This study revealed the importance of a specific selection of yeast strains for wholegrain flours obtained from different cereals or cultivars, in order to enhance the pro-technological, nutritional and nutraceutical traits of fermented doughs.

Nutritional Features and Bread-Making Performance of Wholewheat: Does the Milling System Matter?

Despite the interest in stone-milling, there is no information on the potential advantages of using the resultant wholegrain flour (WF) in bread-making. Consequently, nutritional and technological properties of WFs obtained by both stone- (SWF) and roller-milling (RWF) were assessed on four wheat samples, differing in grain hardness and pigment richness. Regardless of the type of wheat, stone-milling led to WFs with a high number of particles ranging in size from 315 to 710 µm), whereas RWFs showed a bimodal distribution with large (>1000 µm) and fine (<250 µm) particles. On average, the milling system did not affect the proximate composition and the bioactive features of WFs. The gluten aggregation kinetics resulted in similar trends for all SWFs, with indices higher than for RWFs. The effect of milling on dough properties (i.e., mixing and leavening) was sample dependent. Overall, SWFs produced more gas, resulting in bread with higher specific volume. Bread crumb from SWF had higher lutein content in the wheat cv rich in xanthophylls, while bread from RWF of the blue-grained cv had a moderate but significantly higher content in esterified phenolic acids and total anthocyanins. In conclusion, there was no relevant advantage in using stone- as opposed to roller-milling (and vice versa).

Distribution of bioactive compounds in pearled fractions of tritordeum.

Hexaploid tritordeum is the amphidiploid cereal derived from the cross between wild barley and durum wheat. The present study compares two cultivars of tritordeum with other cereals grown in the same experimental area to weigh up its potential use as ingredient for health-valued foods. Tritordeum shows 2.5-fold higher concentration of lutein than common wheat and barley, and 1.2-fold higher than durum wheat, while the concentration of ß-glucans is 5 folds lower than the one observed for barley. Based on the distribution of bioactive compounds in pearled fractions, the use of whole-grain flours seems the best way to exploit the antioxidant potential of tritordeum. Nevertheless, the internal layers of the kernel of this cereal are characterized on average by high concentrations of antioxidants (32.0 mg/kg and 518 mg/kg soluble and cell wall-bound phenolic acids, respectively), making tritordeum interesting also for the production of refined flours rich in bioactive compounds.

Influence of Agricultural Management on Phytochemicals of Colored Corn Genotypes ( Zea mays L.). Part 2: Sowing Time.

Among the agronomic practices carried out in corn cultivation, the early sowing time is increasingly used by farmers of temperate regions to improve yield and reduce mycotoxin contamination of corn grains. The present study determined the influence of sowing time on the phytochemical content of grains of 10 colored genotypes of corn. There was a significant improvement of both grain yield (+26%), thousand kernel weight (+3%), and test weight (+2%) in plots sown early. The early sowing also significantly influenced the chemical composition of corn grains, with an increase in the concentration of cell-wall-bound phenolic acids (+5%) and ß-cryptoxanthin (+23%) and a decrease in the concentration of lutein (-18%) and total anthocyanins (-21%). Environmental conditions that occurred during grain development significantly influenced the phytochemical content of corn grain, and early spring sowing could impart advantages in terms of both productivity and content of some antioxidants of whole-meal corn flour.

Influence of Agricultural Management on Phytochemicals of Colored Corn Genotypes ( Zea mays L.). Part 1: Nitrogen Fertilization.

In this study, the influence of nitrogen (N) fertilization (170 versus 300 kg of N/ha) on the content of bioactive compounds of whole-meal flour of 10 different colored corn genotypes was investigated. Considerable differences in antioxidant capacity and phytochemical concentrations were observed among genotypes. Higher N fertilization rates significantly ( p < 0.05) increased the content of both total cell-wall-bound phenolics and xanthophylls (lutein and zeaxanthin). Nevertheless, the main phenolic acids (ferulic, p-coumaric, and sinapic acids) as well as the antioxidant capacity and content of ß-cryptoxanthin, ß-carotene, and total anthocyanins did not show significant differences as far as the N fertilization rate is concerned. For corn cultivation, the application of high N fertilization rates, generally carried out to obtain higher grain yields, could positively influence the content of some bioactives particularly in years characterized by high rainfall levels responsible for N leaching from the soil.

Application of Fungicides and Microalgal Phenolic Extracts for the Direct Control of Fumonisin Contamination in Maize.

Fungicides and, for the first time, microalgal phenolic extracts (MPE) from Spirulina sp. and Nannochloropsis sp. were applied on maize culture media under field conditions to evaluate their ability to minimize Fusarium species development and fumonisin production. An in vitro assay against F. verticillioides was carried out using maize grains as the culture medium. An open-field experiment was carried out in Northwest Italy under natural infection conditions. The compared treatments were factorial combinations of two insecticide treatments (an untreated control and pyrethroid, used against European Corn Borer), four antifungal treatments (an untreated control, MPE from Spirulina sp., MPE from Nannochloropsis sp., and a synthetic fungicide), and two timings of the application of the antifungal compounds (at maize flowering and at the milk stage). The MPE compounds were capable of inhibiting fumonisin production in vitro more efficiently than tebuconazole. Insecticide application reduced the infection by Fusarium species and subsequent fumonisin contamination. However, fumonisins in maize fields were not significantly controlled by either fungicide or MPE application.

Bioactive compound and antioxidant activity distribution in roller-milled and pearled fractions of conventional and pigmented wheat varieties.

In this study, the chemical composition of pigmented wheats (yellow, purple and blue types), and the distribution of the bioactive compounds in their roller-milled and pearled fractions, were compared with conventional wheats (red and white types). Roller-milling promoted the recovery of total dietary fiber, ß-glucans, phenolic acids and anthocyanins in the bran fraction, which resulted also in a higher total antioxidant activity than the refined flour. Conversely, lutein resulted mainly concentrated in the refined flour. In the same way, the distribution pattern in the pearled fractions differ depending on the bioactive considered. The study highlights that a careful selection of the most appropriate fractionation process should be performed to produce flours rich in bioactive compounds. Roller-milling resulted useful for the production of refined flours rich in xanthophylls, with particular emphasis to the yellow-grained wheats. Contrarily, pearling could be more useful in the valorization of the health potential of anthocyanin-pigmented varieties.

Lack of NLRP3-inflammasome leads to gut-liver axis derangement, gut dysbiosis and a worsened phenotype in a mouse model of NAFLD.

Non-Alcoholic Fatty Liver Disease (NAFLD) represents the most common form of chronic liver injury and can progress to cirrhosis and hepatocellular carcinoma. A "multi-hit" theory, involving high fat diet and signals from the gut-liver axis, has been hypothesized. The role of the NLRP3-inflammasome, which senses dangerous signals, is controversial. Nlrp3-/- and wild-type mice were fed a Western-lifestyle diet with fructose in drinking water (HFHC) or a chow diet. Nlrp3-/--HFHC showed higher hepatic expression of PPAR γ2 (that regulates lipid uptake and storage) and triglyceride content, histological score of liver injury and greater adipose tissue inflammation. In Nlrp3-/--HFHC, dysregulation of gut immune response with impaired antimicrobial peptides expression, increased intestinal permeability and the occurrence of a dysbiotic microbiota led to bacterial translocation, associated with higher hepatic expression of TLR4 (an LPS receptor) and TLR9 (a receptor for double-stranded bacterial DNA). After antibiotic treatment, gram-negative species and bacterial translocation were reduced, and adverse effects restored both in liver and adipose tissue. In conclusion, the combination of a Western-lifestyle diet with innate immune dysfunction leads to NAFLD progression, mediated at least in part by dysbiosis and bacterial translocation, thus identifying new specific targets for NAFLD therapy.

Fibronectin Type III Domain-Containing Protein 5 rs3480 A>G Polymorphism, Irisin, and Liver Fibrosis in Patients With Nonalcoholic Fatty Liver Disease.

Context: Contrasting data have been reported on the role of irisin, a novel myokine encoded by the fibronectin type III domain-containing protein 5 (FNDC5) gene, in nonalcoholic fatty liver disease (NAFLD) pathogenesis. We tested in patients with suspected nonalcoholic steatohepatitis (NASH) the association of FNDC5 variants, hepatic expression, and circulating irisin with liver damage (F2 to F4 fibrosis as main outcome). We also investigated whether irisin modulates hepatocellular fat accumulation and stellate cell activation in experimental models. Methods: We considered 593 consecutive patients who underwent liver biopsy for suspected NASH and 192 patients with normal liver enzymes and without steatosis. FNDC5 rs3480 and rs726344 genotypes were assessed by 5' nuclease assays. Hepatic irisin expression was evaluated in mice fed a high-fat diet or treated with CCl4. The effect of irisin was evaluated in fat-laden HepG2 hepatocytes and in hepatic stellate cells (HSCs). Results: In patients at risk for NASH [odds ratio (OR) = 0.64, 95% confidence interval (CI), 0.47 to 0.87; P = 0.005], and more so in the high-risk subgroup of those with impaired fasting glucose/diabetes (OR = 0.44, 95% CI, 0.26 to 0.74; P = 0.002), the rs3480 A>G variant was independently associated with protection from F2 to F4 fibrosis. Irisin is expressed in human activated HSC, where it mediated fibrogenic actions and collagen synthesis, and is overexpressed in NAFLD patients with F2 to F4 fibrosis and CCl4-treated mice. However, Irisin does not affect fat accumulation in HepG2 and is not induced by high-fat-diet-inducing NAFLD. Conclusions: The FNDC5 rs3480 variant is associated with protection from clinically significant fibrosis in patients with NAFLD, while irisin expression is correlated with the severity of NAFLD and may be involved in extracellular matrix deposition. These data suggest that irisin is involved in regulation of hepatic fibrogenesis.