Egg-Derived Tripeptide IRW Attenuates LPS-Induced Osteoclastogenesis in RAW 264.7 Macrophages via Inhibition of Inflammatory Responses and NF-κB/MAPK Activation

Dental Pulp Stem Cell-Derived Exosomes Regulate Anti-Inflammatory and Osteogenesis in Periodontal Ligament Stem Cells and Promote the Repair of Experimental Periodontitis in Rats

Purpose

Dental pulp stem cell-derived exosomes (DPSC-EXO), which have biological characteristics similar to those of metrocytes, have been found to be closely associated with tissue regeneration. Periodontitis is an immune inflammation and tissue destructive disease caused by plaque, resulting in alveolar bone loss and periodontal epithelial destruction. It is not clear whether DPSC-EXO can be used as an effective therapy for periodontal regeneration. The purpose of this study was not only to verify the effect of DPSC-EXO on reducing periodontitis and promoting periodontal tissue regeneration, but also to reveal the possible mechanism.

Methods

DPSC-EXO was isolated by ultracentrifugation. Then it characterized by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA) and Western Blot. In vitro, periodontal ligament stem cells (PDLSCs) were treated with DPSC-EXO, the abilities of cell proliferation, migration and osteogenic potential were evaluated. Furthermore, we detected the expression of IL-1β, TNF-αand key proteins in the IL-6/JAK2/STAT3 signaling pathway after simulating the inflammatory environment by LPS. In addition, the effect of DPSC-EXO on the polarization phenotype of macrophages was detected. In vivo, the experimental periodontitis in rats was established and treated with DPSC-EXO or PBS. After 4 weeks, the maxillae were collected and detected by micro-CT and histological staining.

Results

DPSC-EXO promoted the proliferation, migration and osteogenesis of PDLSCs in vitro. DPSC-EXO also regulated inflammation by inhibiting the IL-6/JAK2/STAT3 signaling pathway during acute inflammatory stress. In addition, the results showed that DPSC-EXO could polarize macrophages from the M1 phenotype to the M2 phenotype. In vivo, we found that DPSC-EXO could effectively reduce alveolar bone loss and promote the healing of the periodontal epithelium in rats with experimental periodontitis.

Conclusion

DPSC-EXO plays an important role in inhibiting periodontitis and promoting tissue regeneration. This study provides a promising acellular therapy for periodontitis.

Norbergenin prevents LPS-induced inflammatory responses in macrophages through inhibiting NFκB, MAPK and STAT3 activation and blocking metabolic reprogramming

Inflammation is thought to be a key cause of many chronic diseases and cancer. However, current therapeutic agents to control inflammation have limited long-term use potential due to various side-effects. This study aimed to examine the preventive effects of norbergenin, a constituent of traditional anti-inflammatory recipes, on LPS-induced proinflammatory signaling in macrophages and elucidate the underlying mechanisms by integrative metabolomics and shotgun label-free quantitative proteomics platforms. Using high-resolution mass spectrometry, we identified and quantified nearly 3000 proteins across all samples in each dataset. To interpret these datasets, we exploited the differentially expressed proteins and conducted statistical analyses. Accordingly, we found that LPS-induced production of NO, IL1β, TNFα, IL6 and iNOS in macrophages was alleviated by norbergenin via suppressed activation of TLR2 mediated NFκB, MAPKs and STAT3 signaling pathways. In addition, norbergenin was capable of overcoming LPS-triggered metabolic reprogramming in macrophages and restrained the facilitated glycolysis, promoted OXPHOS, and restored the aberrant metabolites within the TCA cycle. This is linked to its modulation of metabolic enzymes to support its anti-inflammatory activity. Thus, our results uncover that norbergenin regulates inflammatory signaling cascades and metabolic reprogramming in LPS stimulated macrophages to exert its anti-inflammatory potential.

Egg White Protein Ovotransferrin-Derived IRW (Ile-Arg-Trp) Inhibits LPS-Induced Barrier Integrity Dysfunction and Inflammation in Caco-2 Cells

Tripeptide IRW derived from egg ovotransferrin was initially identified to be an inhibitor of angiotensin-converting enzyme. Later, IRW has been shown to possess various bioactivities, including anti-inflammatory activity and the ability to suppress colitis development. Nevertheless, its role in protecting intestinal barrier integrity has not been reported. This study aims to investigate the effect of IRW on inhibiting intestinal barrier dysfunction and inflammation in lipopolysaccharide (LPS)-treated Caco-2 cells. Pretreatment with IRW could mitigate the LPS-induced reduction of transepithelial electronic resistance values and decrease the paracellular permeation of differentiated Caco-2 cell monolayers. Meanwhile, IRW restored the expression level and cell surface distribution of the tight junction protein occludin. Furthermore, IRW showed LPS-neutralizing activity and could significantly inhibit LPS-induced activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In conclusion, our study demonstrated the ability of IRW to prevent LPS-induced intestinal barrier dysfunction and prohibit inflammatory responses.

Assessment of Novel Oligopeptides from Rapeseed Napin (Brassica napus) in Protecting HepG2 Cells from Insulin Resistance and Oxidative Stress

Oligopeptides (Thr-His-Leu-Pro-Lys (THLPK), His-Pro-Leu-Lys (HPLK), Leu-Pro-Lys (LPK), His-Leu-Lys (HLK), and Leu-His-Lys (LHK)) are newly identified from rapeseed napin (Brassica napus) protein-derived hydrolysates with the capability of upregulating glucose transporter-4 (GLUT4) expression and translocation. However, whether each of them enhances GLUT4 expression and translocation and their specific mechanisms remain unclear. Here, we assess the effects of the oligopeptides against insulin resistance (IR) and oxidative stress in hepatocytes and screen out the most antidiabetic one. Specifically, compared with other oligopeptides, LPK not only remarkably elevated glucose consumption to 8.45 mmol/L protein; superoxide dismutase (SOD) activity to 319 U/mg protein; GLUT4 expression and translocation; and phosphorylated level of insulin receptor substrate-1 (IRS-1), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) (P < 0.05) but also remarkably attenuated the reactive oxygen species (ROS) level to 2255, lactate dehydrogenase (LDH) activity to 20.5 U/mg protein, malondialdehyde (MDA) content to 241 nmol/mg protein, and NO content to 1302 μmol/mL protein (P < 0.05). These findings demonstrated that antidiabetic oligopeptide LPK possessed the most potential to protect HepG2 cells from IR and oxidative stress via activating IRS-1/PI3K/Akt/GLUT4 and regulating common oxidative markers in vitro.

Chicken Muscle-Derived ACE2 Upregulating Peptide VVHPKESF Inhibits Angiotensin II-Stimulated Inflammation in Vascular Smooth Muscle Cells via the ACE2/Ang (1-7)/MasR Axis

This study aimed to evaluate the modulatory effects of four chicken muscle-derived peptides [VRP, LKY, VRY, and VVHPKESF (V-F)] on angiotensin II (Ang II)-induced inflammation in rat vascular smooth muscle A7r5 cells. Only V-F could significantly attenuate Ang II-stimulated inflammation via the inhibition of NF-κB and p38 MAPK signaling, being dependent on the Mas receptor (MasR) not on the Ang II type 1 or type 2 receptor (AT₁R or AT₂R). V-F accelerated Ang II degradation by enhancing cellular ACE2 activity, which was due to ACE2 upregulation other than a direct ACE2 activation. These findings demonstrated that V-F ameliorated Ang II-induced inflammation in A7r5 cells via the ACE2/Ang (1-7)/MasR axis. Three peptide metabolites of V-F─VHPKESF, PKESF, and SF─were identified but were not considered major contributors to V-F's bioactivity. The regulation of peptide V-F on vascular inflammation supported its functional food or nutraceutical application in the prevention and treatment of hypertension and cardiovascular diseases.

Antioxidant Stress and Anti-Inflammatory Activities of Egg White Proteins and Their Derived Peptides: A Review

Oxidative stress and chronic inflammation are the common pathological bases of chronic diseases such as atherosclerosis, cancer, and cardiovascular diseases, but most of the treatment drugs for chronic diseases have side effects. There is an increasing interest to identify food-derived bioactive compounds that can mitigate the pathological pathways associated with oxidative stress and chronic inflammation. Egg white contain a variety of biologically active proteins, many of which have antioxidant and anti-inflammatory activities and usually show better activity after enzymatic hydrolysis. This review covers the antioxidative stress and anti-inflammatory activities of egg white proteins and their derived peptides and clarifies their mechanism of action in vivo and in vitro. In addition, the link between oxidative stress and inflammation as well as their markers are reviewed. It suggests the potential application of egg white proteins and their derived peptides and puts forward further research prospects.

VF-4 and DR-8 Derived from Salted Egg White Inhibit Inflammatory Activity via NF-κB/PI3K-Akt/MAPK Signal Transduction Pathways in HT-29 Cells Induced by TNF-α

SCOPE

Inflammation is the pathological basis of many chronic diseases, and persistent intestinal inflammation is a key factor in the further development of colon cancer. Egg-derived peptides have been proven to have anti-intestinal inflammation activity. Egg white treated with salt contains a lot of rich protein, whether its peptides have anti-inflammatory activity and how their mechanism of action is still unclear.

METHODS AND RESULTS

In this study, ELISA is used to determine the anti-inflammatory activity of the peptides (VF-4 and DR-8 from salted egg white), and then RNA-seq is used to explore the mechanism of their anti-inflammatory activity, and then verified by western blotting and inhibitors. The results show that VF-4 and DR-8 significantly inhibit TNF-α-induced IL-8 secretion in HT-29 cells in a concentration-dependent manner, and VF-4 show a more significant anti-inflammatory effect than DR-8. The anti-inflammatory mechanism of VF-4 and DR-8 is through inhibiting the activation of Nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3' -kinase(PI3K)-Akt pathways, reducing the production of inflammatory mediators.

CONCLUSION

VF-4 and DR-8 have obvious anti-inflammatory activity, which can reduce intestinal inflammation and inhibit its further development into colon cancer.

Velvet Antler Methanol Extracts Ameliorate Parkinson's Disease by Inhibiting Oxidative Stress and Neuroinflammation: From C. elegans to Mice

Velvet antler is the traditional tonic food or medicine used in East Asia for treating aging-related diseases. Herein, we try to dissect the pharmacology of methanol extracts (MEs) of velvet antler on Parkinson's disease (PD). Caenorhabditis elegans studies showed that MEs decreased the aggregation of α-synuclein and protected oxidative stress-induced DAergic neuron degeneration. In vitro cellular data indicated that MEs suppressed the LPS-induced MAPKs and NF-κB activation, therefore inhibiting overproduction of reactive oxygen species, nitric oxide, tumor necrosis factor-α, and interleukin-6; blocking microglia activation; and protecting DAergic neurons from the microglia-mediated neurotoxicity. In vivo MPTP-induced PD mouse investigations found that MEs prevented MPTP-induced neuron loss in the substantia nigra and improved the behavioral rotating rod performance in MPTP-treated mice by increasing the expression level of tyrosine hydroxylase (TH) and downregulating α-synuclein protein expression. In all, these results demonstrate that MEs ameliorate PD by inhibiting oxidative stress and neuroinflammation.

A Novel Angiotensin Converting Enzyme 2 (ACE2) Activating Peptide: A Reflection of 10 Years of Research on a Small Peptide Ile-Arg-Trp (IRW)

IRW (Ile-Arg-Trp) was identified as an inhibitor of angiotensin converting enzyme (ACE) from egg white protein ovotransferrin through an integrated in silico digestion and quantitative structure and activity relationship prediction in 2011. Oral administration of IRW to spontaneously hypertensive rats (SHRs) can significantly reduce blood pressure, via upregulation of ACE2, but not through the inhibition of ACE. ACE2 converts Ang II into Ang (1-7), thus lowering blood pressure via Mas receptor (MasR); coinfusion of Mas receptor antagonist A779 and IRW in SHRs abolished blood pressure-lowering effect of IRW, supporting a key role of ACE2/Ang (1-7)/MasR axis. Our ongoing study further established new roles of IRW as an antioxidant, an anti-inflammatory agent, an insulin sensitizer, and a bone cell anabolic. Future studies are warranted to understand the unique structure features of this peptide, its mechanisms of action at various targets, its bioavailability and metabolism, and its possible roles toward COVID-19.