OBJECTIVE:

Genital tract infections of gram-negative bacteria lead to a pathogenic condition known as bacterial vaginosis. Endotoxins (lipopolysaccharides: LPS) are the main antigenic components of these bacteria and can trigger the immune system through the secretion of proinflammatory cytokines. Many of the cytokines are known to be involved in the process of embryonic development and implantation of the blastocyst on to a receptive endometrium for successful pregnancy to occur. In earlier studies, in a mouse model it was shown that the normal pattern of expression for IL-1, TNF-α, CSF-1 etc., in the embryos and uterine horns are altered when the animals are exposed to a ‘minimum dose’ of LPS. The current study investigates whether LPS can cause apoptosis in the preimplantation stage embryos as an end effect.

MATERIAL-METHODS:

5µg LPS were injected per mice (weighing ≈ 20 g) on day 0.5 of pregnancy. The degree of apoptosis induced by the ‘minimum dose’ of LPS was assessed by comet assays on individual preimplantation stage embryos.

RESULTS:

‘Minimum dose’ of LPS was found to cause cell deaths in more than 88% of the embryos by the time they reach to the stage of implantation.

DISCUSSION:

We conclude that LPS can cause implantation failure and pregnancy loss due to apoptosis of blastomeres during embryonic development to the blastocysts in-vivo.

Keywords: Lipopolysaccharides, Blastocyst, Implantation, Preganacy