Relaxin-2 (RLN2)

Relaxin-2 (RLN2) is a peptide hormone belonging to the insulin superfamily, composed of two polypeptide chains (A and B) linked by three disulfide bonds, processed from a prorelaxin precursor[1][2][3][4][5]. RLN2 is produced mainly by the corpus luteum during pregnancy but is also expressed in other tissues, including the prostate and heart[3][4][5]. It acts via the G protein-coupled receptor RXFP1 to mediate a range of physiological effects including tissue remodeling, vasodilation, and anti-fibrotic actions, and is critically important for reproductive system adaptations during pregnancy, cardiovascular homeostasis, and extracellular matrix integrity[1][3][4][5]. Recombinant forms like serelaxin are being developed and clinically tested for acute heart failure and possibly fibrosis-related conditions, exploiting its potent vasodilatory and cardioprotective actions[2][4][5]. Key therapeutic and safety challenges include species-specific effects, complex roles in cancer biology, and the challenge of precisely modulating its matrix-remodeling activity outside pregnancy[1][2][5].

Other names

Prorelaxin H2Relaxin B chainRelaxin A chainRLN2H2RLXH2bA12D24.1.1bA12D24.1.2relaxin H2H2-RLXprorelaxin H2H2-preprorelaxinrelaxinovarianof pregnancy

Binds and activates relaxin family peptide receptor 1 (RXFP1; a G protein-coupled receptor), leading to activation of cAMP/PKA, PI3K/Akt, nitric oxide, and MMP signaling pathways; Inhibits transforming growth factor-β (TGF-β) signaling and reduces fibrosis; Induces vasodilation and tissue remodeling.