Effect of Ubiquitin-Proteasome Pathway on Mouse Blastocyst Implantation and Expression of Matrix Metalloproteinases-2 and -91

Abstract

Previous studies have documented that ubiquitin-related proteins are present in human, baboon, rhesus monkey, cow, sheep, and mouse pregnant uteri, indicating that the ubiquitin-proteasome pathway (UPP) may be involved in the extensive uterine remodeling during mammalian early pregnancy, but there is still no direct evidence. A mouse intrauterine injection model was employed to study the direct effect of the UPP on mouse embryo implantation and its possible mechanisms. On Day 3 of pregnancy in each mouse, one of the uterine horns in each mouse was injected with different concentrations of lactacystin, a specific proteasome inhibitor, or anti-ubiquitin antibody, and the other side was used as a control. On days 5, 6, and 7, the number of implanted embryos was counted and the expression and gelatinolytic activities of matrix metalloproteinase-2 (MMP-2) and MMP-9 were studied. Results presented here illustrate that injection of lactacystin and anti-ubiquitin antibody significantly inhibited mouse embryo implantation. Further investigations by reverse transcription-polymerase chain reaction and gelatin zymography showed that MMP-2 and MMP-9 mRNA expression, as well as the gelatinolytic activity of MMP-9 in the lactacystin-treated uterine horn, significantly decreased, whereas the activity of MMP-2 was not significantly affected. The results obtained from this study, together with previous reports, suggest that the UPP is involved in mouse embryo implantation, and UPP's effect on embryo implantation is achieved at least in part by regulating MMP-2 and MMP-9 mRNA expression and the gelatinolytic activity of MMP-9.

Power of Proteomics in Linking Oxidative Stress and Female Infertility

“…Wang et al were able to prove that blocking this pathway inhibited pregnancy in different species including humans [126]. The change of ubiquitin expression in the uterine tissue also altered the activity of the matrix metalloproteinases which are important during the early pregnancy [126, 127]. Ubiquitin levels measured in the secretome of the embryo may therefore be used as a biomarker for noninvasive and easy prediction of successful pregnancy.…”

Protein expression in human cumulus cells as an indicator of blastocyst formation and pregnancy success

“…For known proteins [31] or to correlate protein phosphorylation with embryonic development [32], Western blot analysis has been used. More recently, mass spectrometry (MS) fingerprinting has been demonstrated to provide a reliable approach for the identification of groups of proteins within limited amounts of samples [33,34].…”

Modulation of host ubiquitin system genes in human endometrial cell line infected with Mycobacterium tuberculosis

“…The figure shows mean ± standard error of the mean (error bars) of three independent experiments. *P < 0.05, **P < 0.01, ***P < 0.001 have been shown to be important in early pregnancy [17], and therefore, its imbalance caused by M. tuberculosis may underlie infertility caused by the pathogen. mkrn1 elicits an apoptotic response during stress [18] caused by M. tuberculosis.…”