Trp53 deficient mice predisposed to preterm birth display region-specific lipid alterations at the embryo implantation site

Abstract

Here we demonstrate that conditional deletion of mouse uterine Trp53 (p53d/d), molecularly linked to mTORC1 activation and causally linked to premature uterine senescence and preterm birth, results in aberrant lipid signatures within the heterogeneous cell types of embryo implantation sites on day 8 of pregnancy. In situ nanospray desorption electrospray ionization mass spectrometry imaging (nano-DESI MSI) was used to characterize the molecular speciation of free fatty acids, monoacylglycerol species, unmodified and oxidized phosphatidylcholine (PC/Ox-PC), and diacylglycerol (DG) species within implantation sites of p53d/d mice and floxed littermates. Implantation sites from p53d/d mice exhibited distinct spatially resolved changes demonstrating accumulation of DG species, depletion of Ox-PC species, and increase in species with more unsaturated acyl chains, including arachidonic and docosahexaenoic acid. Understanding abnormal changes in the abundance and localization of individual lipid species early in the progression to premature birth is an important step toward discovering novel targets for treatments and diagnosis.

Automated mass spectrometry imaging of over 2000 proteins from tissue sections at 100-μm spatial resolution

“…The luminal epithelial (LE) cells lining the uterine cavity are surrounded by stromal (S) cells and dispersed glandular epithelial (GE) cells. These cells show unique cell-type-specific protein expression in preparation for the attachment of early embryos to the LE, and subsequent invasion into the S. Distinct molecular signatures across the heterogeneous landscape of the mouse uterus during early pregnancy has made this an ideal model system for evaluating other imaging techniques such as matrix-assisted laser desorption ionization (MALDI) IMS 30,31 and nanodesorption electrospray ionization (NanoDESI) IMS [32][33][34][35] in previous studies. In this study, our proteomic imaging platform was capable of mapping >2000 proteins with 100-µm spatial resolution, thereby capturing the unique protein expression patterns of the LE, S, and GE cell types.…”

Decidual expression and regulation of Fatty acid desaturase 3 during mouse decidualization

“…cPLA2a is crucial for successful pregnancy because of cPLA2a KO mice show small litters, abnormal uterine spacing of embryos and often exhibit pregnancy failures (Bonventre et al 1997, Song et al 2002. Conditional deletion of mouse uterine Trp53 (p53(d/d)), leads to premature uterine senescence and preterm birth, and also causes an increase in arachidonic and docosahexaenoic acid (Lanekoff et al 2016). These data suggest that a balance in arachidonic acid should be essential for decidual development.…”

Characterizing the lipid and metabolite changes associated with placental function and pregnancy complications using ion mobility spectrometry-mass spectrometry and mass spectrometry imaging

“…One of the most powerful uses of MS alone to study pregnancy complications has been with mass spectrometry imaging (MSI). MSI technologies have previously been used to characterize the high and diverse lipid content of decidua [21–24]. MSI has also been applied to normal human placentas and used to determine the specific distribution of SM(d18:1/16:0) in the stem villi and PC(16:0/20:4) in the terminal villi [25].…”

“…The sample is then efficiently transferred to the MS and electrosprayed as highly charged sub-micron droplets that facilitate sensitive MS analysis. Three recent nano-DESI studies have illustrated the success of this technique for imaging lipids and metabolites from uterine sections under ambient conditions and without special sample pre-treatment [22–24]. In the most recent study, implantation sites from a mouse model of preterm birth ( p53 d/d mice) exhibited distinct spatially resolved changes demonstrating depletion of oxidized phosphatidylcholine (Ox-PC) species (Fig.…”

“…In the most recent study, implantation sites from a mouse model of preterm birth ( p53 d/d mice) exhibited distinct spatially resolved changes demonstrating depletion of oxidized phosphatidylcholine (Ox-PC) species (Fig. 3), accumulation of DG species, and increase in species with more unsaturated acyl chains including arachidonic (20:4) and docosahexaenoic acid (22:6) by day 8 of pregnancy [24]. In this mouse model, uterine deletion of Trp53 increases the incidence of preterm birth through an increase in the cyclooxygenase 2 (COX2)/PGF synthase/PGF (2alpha) pathway [56].…”