Quantitative proteomics study of carnosine effect in an animal model of Western diet-induced nonalcoholic fatty liver disease.

The nonalcoholic fatty liver disease (NAFLD), which is closely related to westernized dietary (WD) patterns, displays a rising epidemiological and economic burden. Since there is no pharmacological therapy approved for this disease, mechanistic studies are warranted. In this work, we investigated the action of carnosine (CAR), a natural dipeptide with several protection roles against oxidative stress in the liver of NAFLD rats. NAFLD was induced by WD-rich sugars and fat, verifying the histological evidence of steatosis. As intraperitoneal administration of CAR reversed liver steatosis, the protein profiles of NAFLD liver and CAR NAFLD liver were evaluated by label-free proteomics approach. A total of 2531 proteins were identified and the 230 and 276 were significantly up- and downregulated, respectively, by CAR treatment of NAFLD rats and involved in fundamental pathways such as oxidative stress and lipid metabolism. Perilipin 2 and apolipoprotein E, components of the plasma membrane of vesicle, resulted in highly downregulated in the CAR-treated NAFLD liver. The advanced bioanalytical approach demonstrated the efficacy of CAR in overcoming the main symptoms of NAFLD, ameliorating the steatosis in the liver.

Differentially expressed proteins obtained by label-free quantitative proteomic analysis reveal affected biological processes and functions in Western diet-induced steatohepatitis.

Nonalcoholic steatohepatitis (NASH) is a pathological manifestation with a progressive incidence in response to the epidemic of hepatic steatosis caused primarily by excessive energy intake. The present study unravels affected biological processes and functions by the presence of NASH in rats using a label-free quantitative proteomic strategy. NASH was induced by a Western high-sugar and high-fat diet for 20 weeks. The liver tissue was collected for histology and for a mass spectrometry-based proteomic protocol. The NASH group showed severe lipidosis, hepatocyte ballooning, and the presence of collagen deposition. Among upregulated proteins in NASH perilipin-2 (Plin-2; F6QBA3; difference [diff]: 2.29), ferritin heavy (Fth1; Q66HI5; diff: 2.19) and light (Ftl1; P02793; diff: 1.75) chains, macrophage migration inhibitory factor 1 (Mif; P30904; diff: 1.69), and fibronectin (Fn1; F1LST1; diff: 0.35) were observed, whereas among downregulated proteins, plectin (Q6S399; diff: -3.34), some Cyp2 family proteins of the cytochrome P450 complex, glutathione S-transferases, flavin-containing monooxygenase 1 (Fmo1; P36365; diff: -2.08), acetyl-CoA acetyltransferase 2 (Acat2; Q5XI22; diff: -2.25), acyl-CoA oxidase 2 (Acox2; F1LNW3; diff: -1.59), and acyl-CoA oxidase 3 (Acox3; F1M9A7; diff: -2.41) were observed. Also, biological processes and functions such as LPS/IL-1 inhibition of RXR, fatty acid metabolism, Nrf2-mediated oxidative stress response, xenobiotic metabolism, and PXR/RXR and CAR/RXR activations were predicted to be affected. In conclusion, the liver of rats with NASH induced by Western diet shows a decreased capacity of metabolizing lipids, fatty acids, and xenobiotic compounds that predispose fibrosis development.

Novel low-abundance allergens from mango via combinatorial peptide libraries treatment: A proteomics study.

Mango allergy is a rare condition, which may cause severe hypersensitivity reactions, such as anaphylaxis, angioedema, asthma and contact dermatitis. By exploiting the combinatorial peptide ligand library (CPLL) technology, mango proteomes have been extracted and the presence of traces of allergens assessed via Western blot analysis two-dimensional maps. Upon reactive spot elution and mass spectrometry analyses, four major mango allergens could be identified for the first time and shown to be in common with three of the five known banana species. These allergens include: Mus a 1, Mus a 2 and Mus a 5. Additional mango allergens detected do not seem to be in common with the banana species. In particular, a pectinesterase and a superoxide dismutase, both widely described as allergens, could be identified in mango extracts. Conversely, plain mango extracts not treated with CPLLs did not exhibit any reactive spots in Western blot analysis.

In-depth exploration of Hevea brasiliensis latex proteome and "hidden allergens" via combinatorial peptide ligand libraries.

The proteome of Hevea brasiliensis latex has been explored in depth via combinatorial peptide ligand libraries. A total of 300 unique gene products have been identified in this latex, whose proteome has been largely unknown up to the present. In search for unknown allergens, control latex and eluates from the ligand libraries have been fractionated by two-dimensional mapping, blotted and confronted with sera of 18 patients. In addition to the already known and named Hevea major allergens, we have unambiguously detected several others like, for instance: heat shock protein (81 kDa), proteasome subunit (30 kDa), protease inhibitor (8 kDa), hevamine A (43 kDa) and glyceraldehyde-3-phosphate dehydrogenase (37 kDa). Gene Ontology analysis of analyzed fractions has shown that major functions are substantially unchanged after sample treatment, while novel biological functions appeared that were undetectable in the crude sample.