Embryo biosensing by uterine natural killer cells determines endometrial fate decisions at implantation

Kong, CS; Ordonez, AA; Turner, S; Tremaine, T; Muter, J; Lucas, ES; Salisbury, E; Vassena, R; Tiscornia, G; Fouladi-Nashta, AA; Hartshorne, G; Brosens, JJ; Brighton, PJ

Abstract

Decidualizing endometrial stromal cells (EnSC) critically determine the maternal response to an implanting conceptus, triggering either menstruation-like disposal of low-fitness embryos or creating an environment that promotes further development. However, the mechanism that couples maternal recognition of low-quality embryos to tissue breakdown remains poorly understood. Recently, we demonstrated that successful transition of the cycling endometrium to a pregnancy state requires selective elimination of pro-inflammatory senescent decidual cells by activated uterine natural killer (uNK) cells. Here we report that uNK cells express CD44, the canonical hyaluronan (HA) receptor, and demonstrate that high molecular weight HA (HMWHA) inhibits uNK cell-mediated killing of senescent decidual cells. In contrast, low molecular weight HA (LMWHA) did not attenuate uNK cell activity in co-culture experiments. Killing of senescent decidual cells by uNK cells was also inhibited upon exposure to medium conditioned by IVF embryos that failed to implant, but not successful embryos. Embryo-mediated inhibition of uNK cell activity was reversed by recombinant hyaluronidase 2 (HYAL2), which hydrolyses HMWHA. We further report a correlation between the levels of HYAL2 secretion by human blastocysts, morphological scores, and implantation potential. Taken together, the data suggest a pivotal role for uNK cells in embryo biosensing and endometrial fate decisions at implantation.

Citation

Kong, C., Ordonez, A., Turner, S., Tremaine, T., Muter, J., Lucas, E., …Brighton, P. (2021). Embryo biosensing by uterine natural killer cells determines endometrial fate decisions at implantation. FASEB Journal, 35(4), https://doi.org/10.1096/fj.202002217R

• Journal Article Type: Article
• Acceptance Date: Mar 21, 2021
• Publication Date: 2021
• Deposit Date: Dec 15, 2021
• Publicly Available Date: Dec 15, 2021
• Print ISSN: 0892-6638
• Publisher: Federation of American Society of Experimental Biology (FASEB)
• Peer Reviewed: Peer Reviewed
• Volume: 35
• Issue: 4
• DOI: https://doi.org/10.1096/fj.202002217R
• Keywords: decidualization; embryo implantation; endometrium; hyaluronan; senescence; uterine natural killer cells
• Public URL: https://rvc-repository.worktribe.com/output/1553370