sphingosine-kinase and geniposide

Rheumatoid arthritis (RA) is an angiogenesis-dependent disease caused by the imbalance of pro- and anti-angiogenic factors. More effective strategies to block synovial angiogenesis in RA should be studied. Geniposide (GE), a natural product isolated from the fruit of Gardenia jasminoides Ellis (GJ), is reported to have anti-inflammatory, anti-angiogenic and other pharmacological effects. However, the underlying mechanism through which GE affects synovial angiogenesis in RA remains unclear.. In this research, we aimed to elucidate the effect and potential mechanisms of GE on angiogenesis in RA.. Synovial angiogenesis in patients with RA and a rat model of adjuvant arthritis (AA) was detected by hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and western blottiing. The biological functions of vascular endothelial cells (VECs) and sphingosine kinase 1 (SphK1) translocation were checked by CCK-8, EdU, Transwell, tube formation, co-immunoprecipitation assays, and laser scanning confocal microscopy. The effect of the SphK1 gene on angiogenesis was assessed by transfection of SphK1-siRNA in cells and mices. The effect of GE on VEGF-induced angiogenesis was measured by Matrigel plug assay in a mouse model of AA.. GE effectively inhibited synovial angiogenesis and alleviated the disease process. SphK1, as a new regulatory molecule, has a potentially important relationship in regulating VEGF/VEGFR2 and S1P/S1PR1 signals. SphK1 translocation was activated via the VEGFR2/PKC/ERK1/2 pathway and was closely linked to the biological function of VECs. GE significantly reduced SphK1 translocation, thereby ameliorating the abnormal biological function of VECs. Furthermore, after transfection of SphK1 siRNA in VECs and C57BL/6 mice, silencing SphK1 caused effectively attenuation of VEGF-induced VEC biological functions and angiogenesis. In vivo, the Matrigel plug experiment indicated that GE significantly inhibited pericyte coverage, basement membrane formation, vascular permeability, and fibrinogen deposition.. Our findings suggest that GE inhibited VEGF-induced VEC biological functions and angiogenesis by reducing SphK1 translocation. Generally, studies have revealed that GE down-regulated VEGFR2/PKC/ERK1/2-mediated SphK1 translocation and inhibited S1P/S1PR1 signaling activation, thereby alleviating VEGF-stimulated angiogenesis. The above evidences indicated that angiogenesis inhibition may provide a new direction for RA treatment.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Endothelial Cells; Humans; Iridoids; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; Neovascularization, Pathologic; Phosphotransferases (Alcohol Group Acceptor); Rats; RNA, Small Interfering; Vascular Endothelial Growth Factor A

Imbalance of macrophage polarization plays a critical role in the progression of rheumatoid arthritis (RA). Geniposide (GE) has been shown to exert anti-inflammatory effects. However, the effect of GE on macrophage polarization remains unclear. Here, we investigated the regulation of GE on the imbalance of macrophage polarization in RA and how it functions. We established a mouse model of collagen-induced arthritis (CIA) and isolated bone marrow-derived macrophages (BMDMs). The results confirmed that pro-inflammatory M1 macrophages were dominant in CIA mice, but the polarization imbalance of macrophages was restored to a certain extent after GE treatment. Furthermore, the membrane targeting of sphingosine kinase 1 (SphK1) was increased in BMDMs of CIA mice, as manifested by increased membrane and cytoplasmic expression of p-SphK1 and high secretion level of sphingosine-1-phosphate (S1P). RAW264.7 cells were stimulated with lipopolysaccharide (LPS)-interferon (IFN)-γ or interleukin (IL)-4 to induce M1 or M2 phenotype, respectively, to revalidate the results obtained in BMDMs. The results again observed SphK1 membrane targeting in LPS-IFN-γ-stimulated RAW264.7 cells. Selective inhibition of SphK1 by PF543 or inhibition of the S1P receptors by FTY720 both restored the proportion of M1 and M2 macrophages in LPS-IFN-γ-stimulated RAW264.7 cells, confirming that SphK1 membrane targeting mediated a proportional imbalance in M1 and M2 macrophage polarization. In addition, GE inhibited SphK1 membrane targeting and kinase activity. Taken together, results confirmed that the inhibition of SphK1 membrane targeting by GE was responsible for restoring the polarization balance of macrophages in CIA mice.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Experimental; Arthritis, Rheumatoid; Fingolimod Hydrochloride; Interferon-gamma; Iridoids; Lipopolysaccharides; Macrophages; Mice; Phosphotransferases (Alcohol Group Acceptor); Signal Transduction

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