Protein Digests and Pure Peptides from Chia Seed Prevented Adipogenesis and Inflammation by Inhibiting PPARγ and NF-κB Pathways in 3T3L-1 Adipocytes

The objective was to evaluate the mechanisms of digested total proteins (DTP), albumin, glutelin, and pure peptides from chia seed (Salvia hispanica L.) to prevent adipogenesis and its associated inflammation in 3T3-L1 adipocytes. Preadipocytes (3T3-L1) were treated during differentiation with either DTP or digested albumin or glutelin (1 mg/mL) or pure peptides NSPGPHDVALDQ and RMVLPEYELLYE (100 µM). Differentiated adipocytes also received DTP, digested albumin or glutelin (1 mg/mL), before (prevention) or after (inhibition) induced inflammation by addition of conditioned medium (CM) from inflamed macrophages. All treatments prevented adipogenesis, reducing more than 50% the expression of PPARγ and to a lesser extent lipoprotein lipase (LPL), fatty acid synthase (FAS), sterol regulatory element-binding protein 1 (SREBP1), lipase activity and triglycerides. Inflammation induced by CM was reduced mainly during prevention, while DTP decreased expression of NF-κB (−48.4%), inducible nitric oxide synthase (iNOS) (−46.2%) and COX-2 (−64.5%), p < 0.05. Secretions of nitric oxide, PGE2 and TNFα were reduced by all treatments, p < 0.05. DTP reduced expressions of iNOS (−52.1%) and COX-2 (−66.4%). Furthermore, digested samples and pure peptides prevented adipogenesis by modulating PPARγ and additionally, preventing and even inhibiting inflammation in adipocytes by inhibition of PPARγ and NF-κB expression. These results highlight the effectiveness of digested total proteins and peptides from chia seed against adipogenesis complications in vitro.

In vitro dipeptidyl peptidase IV inhibitory activity and in situ insulinotropic activity of milk and egg white protein digests

Dietary proteins are involved in the regulation of glucose homeostasis by different mechanisms. Food protein digestion products are reported to inhibit dipeptidyl peptidase IV (DPP-IV), induce incretin secretion or directly...

A combined microphysiological-computational omics approach in dietary protein evaluation

The ever-growing world population puts pressure on food security. To tackle this, waste stream proteins and novel protein sources need to be evaluated for nutritional value, which requires information on digesta peptide composition in comparison to established protein sources and coupling to biological parameters. Here, we present a novel combined experimental and computational approach comparing seventeen protein sources with cow’s whey protein (WPC) as benchmark. In vitro digestion was followed by proteomics analysis and statistical model clustering based on Bayesian Information Criterion. Next, we incorporated functional protein data after evaluating the effects of eighteen protein digests on intestinal barrier integrity, viability, brush border enzyme activity and immune parameters using a bioengineered intestine. Our data show that a holistic approach allows evaluating a dietary protein’s potential for delivery of bioactive peptides, where protein source (animal, plant or novel source-derived) does not seem to be the driving force for clustering.

Protein Digests and Pure Peptides from Chia Seed (Salvia hispanica L) Prevented Adipogenesis and Its Associated Inflammation by Inhibition of PPAR-γ and NF-κB Pathways

Objectives To evaluate the mechanism of action of the effect of digested total proteins (DTP), albumin, and glutelin from chia seed to prevent and inhibit inflammation in 3T3-L1 adipocytes. Methods Preadipocytes (3T3-L1) were differentiated into mature adipocytes and received DTP, digested albumin, or glutelin (1 mg/ml) from chia seed together with conditioned medium (CM) from inflamed macrophages during 48 h (prevention), or the digested samples were added after 48 h of CM-stimulated inflammation (inhibition). ROS and cytokines secretion (IL-10, IL-12, IL-6, MCP-1, PGE2, and TNF-α) were analyzed by ELISA and lipid accumulation by oil red-O staining, triglyceride content, lipase activity and expression of proteins (PPAR-γ, SREBP1, FAS, LPL, COX-2, iNOS, and NF-κB) by western-blot. The interactions of peptides with FAS, MAGL, and PPAR-γ were evaluated in silico. Data analyses were performed in triplicate from two independent experiments by ANOVA and post-hoc of Tukey (P &lt; 0.05). Results DTP and digested albumin and glutelin in both, prevention and inhibition of induced inflammation, decreased the expression of PPAR-γ more than 50% (P &lt; 0.05). Digested samples reduced TNF-α secretion, ROS production, lipid accumulation, iNOS and COX-2 expression, especially glutelin (−71, −53, −15, −75, and -85%, respectively) on prevention of inflammation. Albumin digest inhibited NO and PGE2 (−42 and 64%, respectively). DTP reduced the lipase activity (−13%), triglyceride content (−27%), and NF-κB expression (−48%) (P &lt; 0.05). On inhibition of inflammation, only SREBP-1 expression was reduced more than 33% (P &lt; 0.05) by every digested protein. DTP was effective to reduce LPL (-32%), FAS (−29%), iNOS (−52%), and COX-2 (−66%) expression, as well as NO secretion (−15%), and triglyceride content (−18%) (P &lt; 0.05). Peptides TGPSPTAGPPAPGGGTH and YLGAHPGTAN, from digested albumin, showed the highest interaction with PPAR-γ (−9.1 kcal/mol) and MAGL (−7.8 kcal/mol), respectively. Peptide APSPPVLGPP from DTP, showed the highest interaction with FAS (−9.8 kcal/mol). Conclusions Digested samples from chia seed were effective in preventing and even inhibiting inflammation in adipocytes by inhibition of PPAR-γ and NF-κB pathways which highlight the effectiveness these digested proteins against obesity complications. Funding Sources CNPq and CAPES (Brazil), and NIFA HATCH (USA).

Modification of Luffa Sponge for Enrichment of Phosphopeptides

The enrichment technique is crucial to the comprehensive analysis of protein phosphorylation. In this work, a facile, green and efficient synthetic method was set up for quaternization of luffa sponge. The resultant luffa sponge showed strong anion-exchange characteristics and a high adsorption ability for phosphate ions. Along with the unique physical properties, e.g., tenacity and porous texture, quaternized luffa sponge was demonstrated to be a well-suited solid-phase extraction (SPE) material. The quaternized luffa sponge-based SPE method was simple, cost-effective and convenient in operation, and was successfully applied to the capture of phosphopeptides from protein digests. The enrichment approach exhibited exceptionally high selectivity, sensitivity and strong anti-interference ability. Four phosphopeptides were still detected by using the digest mixture of β-casein and bovine serum albumin with a molar ratio of 1:100. 21 phosphopeptides were identified from the tryptic digest of non-fat milk.

adductomicsR: A package for detection and quantification of protein adducts from mass spectra of tryptic digests

ABSTRACTSummaryLiquid chromatography-high resolution mass spectrometry (LC-HRMS) has been used to establish a method, referred to as ‘adductomics’, for characterisation of putative protein adducts at selected loci in human serum albumin (HSA). Applications of this method have been limited by the lack of software for untargeted analysis of modified peptides in protein digests. Here we present adductomicsR, an open-source R package for processing LC-HRMS data from analysis of adducted HSA peptides. The software interrogates mass spectra to correct for retention-time drift, and to discover and quantify putative adducts along with those for a housekeeping peptide and internal standard.Availability and implementationadductomicsR is written in R and publicly available at https://github.com/JosieLHayes/adductomicsR, which includes a vignette with example data.Supplementary informationmzXML files for the vignette and test dataset are available in an associated data package adductData (https://github.com/JosieLHayes/adductData)[email protected] SectionAPPLICATIONS NOTE