PGE2 Signal Through EP2 Promotes the Growth of Articular Chondrocytes

Abstract

EP2 was identified as the major PGE2 receptor expressed in articular cartilage. An EP2 agonist increased intracellular cAMP in articular chondrocytes, stimulating DNA synthesis in both monolayer and 3D cultures. Hence, the EP2 agonist may be a potent therapeutic agent for degenerative cartilage diseases.

Shear-induced Interleukin-6 Synthesis in Chondrocytes

“…In agreement with previously published data from primary human chondrocytes (26), T/C-28a2 cells express EP2, EP3 and very low levels of EP4, but lack EP1, receptors (supplemental Fig. S2A).…”

“…Li et al (14) reported that EP2 and EP4 and to a lesser extent EP3 are expressed in human adult articular cartilage. In contrast, Aoyama et al concluded that EP2 and EP3 are abundantly present in human articular chondrocytes isolated from four individuals primarily of young ages (26). Li et al (14,26) attributed their differences to age variations between the cartilage specimens used in these two studies, and speculated that EP3 may be more prevalent in cartilage of a younger age.…”

“…In contrast, Aoyama et al concluded that EP2 and EP3 are abundantly present in human articular chondrocytes isolated from four individuals primarily of young ages (26). Li et al (14,26) attributed their differences to age variations between the cartilage specimens used in these two studies, and speculated that EP3 may be more prevalent in cartilage of a younger age. Our data reveal that human T/C-28a2 chondrocytes express EP2, EP3, and very low levels of EP4, but lack EP1, receptors.…”

Temporal expression of calcium/calmodulin‐dependent adenylyl cyclase isoforms in rat articular chondrocytes: RT‐PCR and immunohistochemical localization

“…These include the expression of P 1 and P 2 purine receptors (Koolpe et al 1999;Kudirka et al 2007), prostaglandin receptors (Aoyama et al 2005), adenosine receptors (Varani et al 2008) and adrenergic receptors (Lai & Mitchell, 2008). Expression of these receptors along with the expression of Ca 2+ /CaMdependent AC isoforms in articular chondrocytes suggests the complexity of signalling pathways.…”

“…Expression of these receptors along with the expression of Ca 2+ /CaMdependent AC isoforms in articular chondrocytes suggests the complexity of signalling pathways. The expression of G-protein coupled receptors and their downstream signalling pathways demonstrate a chondrocyte-matrix interaction, which is essential to maintain the integrity of articular cartilage (Aoyama et al 2005;Kudirka et al 2007;Lai & Mitchell, 2008;Varani et al 2008). Furthermore, the importance of articular chondrocyte-matrix interaction is demonstrated in age-related changes in articular cartilage.…”