iridoids and sphingosine-1-phosphate

The changes of fibroblast-like synoviocytes (FLSs) and vascular endothelial cells (VECs) biological functions are closely related to angiogenesis in rheumatoid arthritis (RA). Nevertheless, how the crosstalk between FLSs and VECs interferes with RA is far from being clarified. Herein, we studied the effect of the reciprocal interactions between FLSs and VECs on angiogenesis and mechanism of geniposide (GE). After administration of GE, improvement of synovial hyperplasia in adjuvant arthritis rats was accompanied by downregulation of SphK1 and p-Erk1/2. The dynamic interaction between FLSs and VECs triggers the release of S1P by activating p-Erk1/2 and SphK1, then activating RhoA-F-actin and Ras-Erk1/2 pathways. When exposed to the inflammatory microenvironment mediated by FLSs-VECs crosstalk, proliferation, migration, and permeability of VECs were enhanced, the angiogenic factors were imbalanced. Meanwhile, the proliferation and secretory ability of FLSs increased. Interestingly, depletion of S1P or blocking of the activation of SphK1 by GE and PF-543 prevented the changes. In conclusion, S1P released during FLSs-VECs crosstalk changed their biological functions by activating RhoA-F-actin and Ras-Erk1/2 pathways. GE acted on p-Erk1/2 and SphK1, inhibited the secretion of S1P, and blocked the interplay between FLSs and VECs. These results provide new insights into the mechanism of angiogenesis in RA.

Topics: Actins; Animals; Arthritis, Experimental; Cell Movement; Cell Proliferation; Cells, Cultured; Endothelial Cells; Fibroblasts; Iridoids; Lysophospholipids; Rats; Signal Transduction; Sphingosine; Synovial Membrane

Rheumatoid arthritis (RA) is a common inflammatory autoimmune disease characterized by the formation of joint synovitis and pannus. Sphingosine 1-phosphate (S1P) is an important mediator related to angiogenesis, inflammation and autoimmunity. As Geniposide (GE) has potent immuno-modulation function, we investigated the effects on the dynamic balance of angiogenesis-related factors and Sphingosine kinase 1 (SphK1)-S1P-S1P receptor 1 (S1PR1) signal transduction in adjuvant-induced arthritis (AA) rats.. The model evaluation was performed from paw swelling degree, arthritis index and movement score. The immunohistochemistry and enzyme-linked immunosorbent assay were used to study the microvascular density (MVD) and pro/anti-angiogenic factors levels. The cell viability was examined by cell counting kit-8 assay. SphK1, S1PR1 mRNA and protein levels in fibroblast-like synoviocytes (FLSs) were detected by quantitative real-time polymerase chain reaction and Western blotting.. The results showed that GE can apparently suppressed the inflammatory pathological status. The arthritis index, paw swelling and MVD of AA rats were decreased with dose dependence (. It indicated that GE reduces the activity of SphK1 by restoring the dynamic balance between pro/anti-angiogenic factors, thereby interfering with SphK1-S1P-S1PR1 signal transduction, reducing the formation of synovial microvessels and exerting anti-angiogenesis effect of RA.

Topics: Animals; Cell Survival; Cells, Cultured; Drug Delivery Systems; Iridoids; Lysophospholipids; Male; Neovascularization, Pathologic; Phosphotransferases (Alcohol Group Acceptor); Random Allocation; Rats; Rats, Sprague-Dawley; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors

Geniposide (GE) is an iridoid glycoside compound with anti-inflammatory effect. The potential of sphingosine 1-phosphate (S1P) as a plasma marker in human diseases was suggested recently in the literature, which demonstrated that, in patients with inflammatory diseases, plasma S1P was elevated. It follows that the obstructive coronary artery disease can be predicted with serum S1P. Therefore, S1P can also be potentially used as a pharmacodynamic marker to study adjuvant arthritis (AA) rats. In the current study, a UHPLC-MS/MS method combined with the microdialysis sampling technique (using FTY720 phosphate as an internal standard) was adopted and validated to measure S1P levels in the hemodialysis fluid and joint cavity dialysates of AA rats after oral administration of GE. A S1P concentration-time curve in the dialysate was established in this study. It was demonstrated that GE exerted an anti-inflammatory effect by reducing AA-induced elevated S1P levels. It is showed that changes in S1P concentrations over time can be used to monitor the pharmacodynamic effects of GE in treating AA rats in pharmacodynamic studies.

Topics: Animals; Arthritis, Experimental; Chromatography, High Pressure Liquid; Drug Stability; Iridoids; Linear Models; Lysophospholipids; Male; Microdialysis; Random Allocation; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Sensitivity and Specificity; Sphingosine; Tandem Mass Spectrometry