COX-2 plays a role in angiogenic DBA(+) uNK cell subsets activation and pregnancy protection in LPS-exposed mice.
Placenta 2016;
44:34-45. [PMID:
27452436 DOI:
10.1016/j.placenta.2016.06.006]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 06/02/2016] [Accepted: 06/10/2016] [Indexed: 12/16/2022]
Abstract
INTRODUCTION
Although uterine Natural Killer (uNK) cells have cytoplasmic granules rich in perforin and granzymes, these cells do not degranulate in normal pregnancy. DBA lectin(+) uNK cells produce angiogenic factors which stimulate remodeling of uterine arterioles to increase blood flow within the growing feto-placental unit. We sought to investigate the importance of COX-2 on mouse pregnancy inoculated with Gram-negative bacteria Lipopolysaccharide (LPS) by treating with a selective COX-2 inhibitor (nimesulide).
METHODS
We have combined histochemical, immunohistochemical, stereological, morphometric, behavioral, and litter analyses to investigate mouse pregnancy inoculated with LPS with or without pre-treatment with nimesulide 30 min before LPS injections, focusing on DBA(+) uNK cell response and viability of the pregnancy.
RESULTS
LPS caused sickness behavior, an immature DBA(+) uNK influx, decreased mature DBA(+) uNK cell numbers, and triggered a new DBA(low) uNK appearance. These effects of LPS, except the sickness behavior, were prevented by nimesulide. COX-2 inhibition also prevented the down-regulation of uNK perforin and spiral arteriole α-actin expression stimulated by LPS. While the litter size from Nimesulide + LPS-treated mothers was significantly smaller compared to those from LPS-treated group, nimesulide alone showed no effect on the offspring.
DISCUSSION
Collectively, our data indicate that COX-2 changes angiogenic DBA(+) uNK cells in order to protect mouse pregnancy after LPS injection.
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