Effect of formyl peptide receptor 2 in recurrent spontaneous abortion through p38 MAPK pathway / 解剖学报

Objective To explore the express of formyl peptide receptor 2(FPR2) in villi of recurrent spontaneous abortion ( RSA) , the effect on proliferation, migration and invasion of trophoblast, and the mechanism to clarify the effect of FPR2 on trophoblast function and explore its role and mechanism in recurrent spontaneous abortion. Methods Clinical villus specimens of 30 nonnal and 30 RSA patients were collected. Immunohistochemical staining, Real-time PCR and Western blotting were used to detect the location and expression of FPR2 in villi of patients with RSA and nonnal pregnant women. CRISPR/Cas-9 technique was used to knock down FPR2 in HTR-8/SVneo cells, CCK-8 assay, wound healing and Transwell assays were used to detennine the ability of cell viability, migration and invasion. Immunofluorescent staining and Western blotting were used to analyze the changes of phosphorylated p38 MAPK ( p-p38 MAPK)/p38 MAPK protein expression after applying with p38 MAPK inhibitor SB203580 alone or in combination. Results The expression of FPR2 in villi of patients with RSA increased. FPR2 knock-down improved the biological functions of HTR-8/Svneo cells such as proliferation, migration and invasion significantly. The expression of p-p38 MAPK was up-regulated significantly by FPR2 knock-down, and the ability enhancement of migration and invasion of trophoblasts was reversed partially by SB203580 which inhibits p38 MAPK pathway. FPR2 knock-down caused the change of p38 MAPK signaling pathway related to proteins. Conclusion FPR2 is highly expressed in trophoblasts of RSA patients, and inhibits the migration and invasion of trophoblasts through p38 MAPK signaling pathway, which ma)' play an important role in RSA.

Paeonol inhibits rheumatoid arthritis through formyl peptide receptors / 中国药理学通报

Aim To investigate the pharmacological effects of paeonol as a formyl peptide receptor activator on rheumatoid arthritis (HA).Methods The target rlataset was obtained from the high throughput Gene Expression Database ( GEO) , and multiple data sets were combined by USING R language to explore three groups of macrophage differentially expressed genes ( DEGs) in untreated,lipopolysaccharide (LPS) treat¬ment and paeonol and LPS treatment, and their enrich-ment pathway was analyzed.Protein-protein interaction (PPI) networks were constructed in the STRING data¬base anrl visualized in Cytoscape software.The inhibi¬tor}' effect of Hub gene formyl peptide receptor ( FPR) on RA inflammation was validated by TNF-cx stimula¬tion of fibroblast synovial cells ( FLS).Results Through bioinformatics analysis, 169 differential genes ( DEGs) related to inflammation and 275 DEGs related to the mechanism of paeonol action were obtained.Combined analysis of the two groups of DEGs showed that FPR played a key role in the anti-inflammatory mechanism of paeonol.Further studies on the mecha¬nism of paeonol showed that paeonol activated FPR, and the inhibitory effect of paeonol on FLS inflamma¬tion was rescued by TRP-ARg-TRP-TRP-TRP-TRP- TRP-TRP-NH2 (WRW4).Conclusion Paeonol can inhibit the inflammatory development of RA through the FPR pathway.

Buyang Huanwutang Alleviated Oxidative Stress Following Cerebral Ischemia/Reperfusion in Rats by Formyl Peptide Receptor 2 / 中国实验方剂学杂志

Objective:To investigate the role of formyl peptide receptor 2 （FPR2） in the inhibitory effects of Buyang Huanwutang （BYHWT） on the oxidative stress and its protective effects on cerebral ischemia-reperfusion in rats. Method:Forty-eight male SD rats were randomly divided into sham group， model group， BYHWT group and BYHWT combined with FPR2 inhibitor （Boc-2） group. In the sham group， only the vessels were isolated. In other groups， the middle cerebral artery occlusion （MCAO） model was constructed using the modified Longa method and reperfused after 2 h of ischemia. BYHWT （16 g·kg^-1） was given by gavaged twice daily after reperfusion in BYHWT group and BYHWT+Boc-2 group. Boc-2 （0.4 mg·kg^-1） was injected intraperitoneally 30 min before surgery. Equal volume of saline were given instead in sham and model group. After 24 h of reperfusion， Fluoro-Jade C （FJC） staining was performed to observe the changes in the number of FJC-positive cells. Western blot was performed to detect the expression of apoptosis-related B-cell lymphoma-2 (Bcl-2)， Bcl-2 associated X (Bax)， and cleaved aspartic acid cysteine proteolytic enzyme-3（Caspase-3）. Besides， superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione （GSH）， and nitric oxide （NO） was measured. The mean fluorescence intensity of nicotinamide adenine dinucleotide phosphate Ⅱ（NADPH） oxidase 2 （NOX2） was examined by immunofluorescence. Result:Compared with sham group， the model group showed increased number of FJC-positive cells （<italic>P</italic><0.01）， decreased Bcl-2 expression （<italic>P</italic><0.01）， increased Bax and cleaved Caspase-3 expression （<italic>P</italic><0.01）， increased NO and MDA content （<italic>P</italic><0.05，<italic>P</italic><0.01）， decreased GSH and SOD activities （<italic>P</italic><0.05，<italic>P</italic><0.01）， and increased NOX2 expression （<italic>P</italic><0.01）. Compared with model group， there were decreased FJC-positive cells （<italic>P</italic><0.01）， up-regulated Bcl-2 expression （<italic>P</italic><0.01） with down-regulated cleaved Caspase-3 and Bax （<italic>P</italic><0.05，<italic>P</italic><0.01）， decreased NO and MDA （<italic>P</italic><0.05，<italic>P</italic><0.01） with increased GSH and SOD （<italic>P</italic><0.01）， and decreased NOX2 expression （<italic>P</italic><0.01） in the BYHWT group. All the above effects were partially blocked by Boc-2. Conclusion:BYHWT can reduce oxidative stress injury and inhibit apoptosis in cerebral ischemia/reperfusion rats， which may be related with the down-regulation of NOX2 expression by FPR2.

Functionally diverse ligands modulate different activation states of the formyl peptide receptor 2, a G protein-coupled receptor / 中国药理学与毒理学杂志

OBJECTIVE To identify the mechanisms by which the formyl peptide receptor 2 (FPR2) mediates both inflammatory and anti-inflammatory signaling in an agonist-dependent manner. METHODS Cells expressing FPR2 were incubated with weak agonists, Aβ42 and Ac2-26, before stimulation with a strong agonist, WKYMVm. Calcium mobilization, cAMP inhibition and MAP kinase activation were measured. Intramolecular FRET were determined using FPR2 constructs with an ECFP attached to the C- terminus and a FlAsH binding motif embedded in the first or third intracellular loop (IL1 or IL3, respectively). RESULTS Aβ42 did not induce significant Ca2 + mobilization, but positively modulated WKYMVm-induced Ca2 + mobilization and cAMP reduction in a dose-variable manner within a narrow range of ligand concentrations. Treating FPR2-expressing cells with Ac2-26, a peptide with anti-inflam?matory activity, negatively modulated WKYMVm-induced Ca2 + mobilization and cAMP reduction. Intra?molecular FRET assay showed that stimulation of the receptor constructs with Aβ42 brought the C-terminal domain closer to IL1 but away from IL3. An opposite conformational change was induced by Ac2-26. The FPR2 conformation induced by Aβ42 corresponded to enhanced ERK phosphorylation and attenuated p38 MAPK phosphorylation, whereas Ac2-26 induced FPR2 conformational change corresponding to elevated p38 MAPK phosphorylation and reduced ERK phosphorylation. CONCLUSION Aβ42 and Ac2-26 induce different conformational changes in FPR2. These findings provide a structural basis for FPR2 mediation of inflammatory vs anti-inflammatory functions and identify a type of receptor modulation that differs from the classic positive and negative allosteric modulation.