As a multifaceted adipokine, chemerin has been found to perform functions vital for immunity, adiposity, and metabolism through its three known receptors (chemokine-like receptor 1, CMKLR1; G-protein-coupled receptor 1, GPR1; C-C motif chemokine receptor-like 2, CCRL2). Chemerin and the cognate receptors are also expressed in the hypothalamus, pituitary gland, testis, ovary, and placenta. Accumulating studies suggest that chemerin participates in normal reproduction and underlies the pathological mechanisms of certain reproductive system diseases, including polycystic ovary syndrome (PCOS), preeclampsia, and breast cancer. Herein, we present a comprehensive review of the roles of the chemerin system in multiple reproductive processes and human reproductive diseases, with a brief discussion and perspectives on future clinical applications.

High expression of CINCs as well IL-1a and CXCL5/LIX suggests their potent roles in the pathogenicity of endometritis.

Studies have shown that sFlt-1 overproduction stimulated by excess VEGF of deciduous origin in trophoblasts can cause preeclampsia. However, the mechanism underlying how VEGF regulates sFtl-1 expression in trophoblasts remains unknown. To address this issue, JEG3 and HTR-8/SV neo (HTR8) trophoblast cell lines were used to investigate the signaling pathways involved in the regulation of sFlt-1 production via VEGF overexpression in vitro. JEG3 (VEGF-GFP-JEG3, V-J) and HTR8 (VEGF-GFP-HTR8, V-H) cells overexpressing VEGF165 were established by infecting the JEG3 and HTR8 cell lines with lentivirus expressing VEGF165. Both the mRNA and protein levels of VEGF and sFlt-1 were dramatically up-regulated in the V-J and V-H cells compared to the JEG3 and HTR8 cells, and they were significantly decreased after treatment with an Flt-1 receptor inhibitor (MK-2461), a KDR receptor inhibitor (XL-184), or an Flt-1 and KDR receptor inhibitor (ABT-869). The mRNA levels of sFlt-1, Flt-1, and KDR were increased in V-H cells after treatment, and the VEGF-A mRNA levels were also elevated. The migration and invasion abilities of JEG3 and HTR8 cells were decreased after VEGF overexpression, and this reduction could be reversed with VEGF receptor inhibitor treatment. In addition, after the different treatments, the cell migration rates of V-J cells were significantly increased compared with the control treatment. Taken together, these results indicate that sFlt-1 up-regulation by VEGF may be mediated by the VEGF/Flt-1 and/or VEGF/KDR signaling pathways. However, elucidating which pathway plays this key role requires further investigation.