CP-25 inhibits PGE2-induced angiogenesis by down-regulating EP4/AC/cAMP/PKA-mediated GRK2 translocation.

G protein-coupled receptor kinase 2 (GRK2), a type of cytosolic enzyme, transiently translocates to the plasma membrane upon G protein-coupled receptors (GPCRs) activation, and it also binds to extracellular signal-regulated kinase (ERK) to inhibit the activation of ERK. GRK2 deficiency in endothelial cells (ECs) leads to increased pro-inflammatory signaling and promotes recruitment of leukocytes to activated ECs. However, the role of GRK2 in regulating angiogenesis remains unclear. Here, we show that GRK2 is a novel regulatory molecule on migration and tube formation of ECs, vessel sprouting ex vivo and angiogenesis in vivo. We identify that EP4/AC/cAMP/protein kinase A (PKA)-mediated GRK2 translocation to cells membrane decreases the binding of GRK2 and ERK1/2 to inhibit ERK1/2 activation, which promotes prostaglandin E2 (PGE2)-induced angiogenesis. GRK2 small interfering RNA (siRNA) inhibits the increase in PGE2-induced HUVECs migration and tube formation. In vivo, PGE2 increases ECs sprouting from normal murine aortic segments and angiogenesis in mice, but not from GRK2-deficient ones, on Matrigel. Further research found that Lys220 and Ser685 of GRK2 play an important role in angiogenesis by regulating GRK2 translocation. Paeoniflorin-6'-O-benzene sulfonate (CP-25), as a novel ester derivative of paeoniflorin (pae), has therapeutic potential for the treatment of adjuvant arthritis (AA) and collagen-induced arthritis (CIA), but the underlying mechanism of CP-25 on angiogenesis has not been elucidated. In our study, CP-25 inhibits the migration and tube formation of HUVECs, and angiogenesis in mice by down-regulating GRK2 translocation activation without affecting GRK2 total expression. Taken together, the present results revealed that CP-25 down-regulates EP4/AC/cAMP/PKA-mediated GRK2 translocation, restoring the inhibition of GRK2 for ERK1/2, thereby inhibiting PGE2-stimulated angiogenesis.

Han CC ，Liu Q ，Zhang Y ，Li YF ，Cui DQ ，Luo TT ，Zhang YW ，Wang XM ，Wang C ，Ma Y ，Wei W ... -  《-》

GRK2 Mediated Abnormal Transduction of PGE2-EP4-cAMP-CREB Signaling Induces the Imbalance of Macrophages Polarization in Collagen-Induced Arthritis Mice.

Yang X ，Li S ，Zhao Y ，Li S ，Zhao T ，Tai Y ，Zhang B ，Wang X ，Wang C ，Chen J ，Wang Q ，Zhang L ，Xu D ，Chang Y ，Wei W ... -  《Cells》

CP-25 reverses prostaglandin E4 receptor desensitization-induced fibroblast-like synoviocyte dysfunction via the G protein-coupled receptor kinase 2 in autoimmune arthritis.

Jia XY ，Chang Y ，Wei F ，Dai X ，Wu YJ ，Sun XJ ，Xu S ，Wu HX ，Wang C ，Yang XZ ，Wei W ... -  《-》

Regulatory effects of paeoniflorin-6'-O-benzene sulfonate (CP-25) on dendritic cells maturation and activation via PGE2-EP4 signaling in adjuvant-induced arthritic rats.

Jia XY ，Chang Y ，Sun XJ ，Wei F ，Wu YJ ，Dai X ，Xu S ，Wu HX ，Wang C ，Yang XZ ，Wei W ... -  《-》

CP-25 exerts anti-angiogenic effects on a rat model of adjuvant-induced arthritis by promoting GRK2-induced downregulation of CXCR4-ERK1/2 signaling in endothelial cells.

Zhang M ，Gao M ，Chen J ，Song L ，Wei W ... -  《-》