Abnormal regulation of an enzyme in the inner wall of the uterus may be one root of infertility and miscarriage.
The enzyme, SGK1, regulates sodium transport and its levels are known to be altered in infertile women. Jan Brosens at Warwick Medical School in Coventry, UK, and his colleagues injected female mice post-coitus with an active version of the gene. Embryos failed to implant and the animals showed either reduced or no expression of key implantation genes. Deleting the Sgk1 gene in females resulted in implantation but later led to a reduction in litter size and signs of uterine bleeding. Silencing the gene in a class of human uterine cells disrupted the activation of molecules that mop up damaging free radicals.
The study reveals two distinct fertility-promoting roles for SGK1 in the uterus: it must be downregulated to enhance embryo implantation but is needed during pregnancy to help support the embryo.