Trisomy 21 is Associated with Caspase-2 Upregulation in Cytotrophoblasts at the Maternal-Fetal Interface

Impaired placentation is implicated in poor perinatal outcomes associated with Trisomy 21. Earlier studies revealed abnormal cytotrophoblast differentiation along the invasive pathway as a contributing mechanism. To further elucidate the causes, we evaluated Caspase-2 expression at the protein level (immunolocalization and immunoblot) in samples from Trisomy 21 (n = 9) and euploid (n = 4) age-matched placentas. Apoptosis was investigated via the TUNEL assay. An immunolocalization approach was used to characterize Caspase-3, Fas (CD95), and Fas ligand in the same samples. Caspase-2 was significantly overexpressed in Trisomy 21 placentas, with the highest expression in villous cores and invasive cytotrophoblasts. Immunolocalization showed that Caspase-3 had a similar expression pattern as Caspase-2. Using the TUNEL approach, we observed high variability in the number of apoptotic cells in biopsies from different regions of the same placenta and among different placentas. However, Trisomy 21 placentas had more apoptotic cells, specifically in cell columns and basal plates. Furthermore, Caspase-2 co-immunolocalized with Fas (CD95) and FasL in TUNEL-positive extravillous cytotrophoblasts, but not in villous cores. These results help explain the higher levels of apoptosis among placental cells of Trisomy 21 pregnancies in molecular terms. Specifically, the co-expression of Caspase-2 and Caspase-3 with other regulators of the apoptotic process in TUNEL-positive cells suggests these molecules may cooperate in launching the observed apoptosis. Among trophoblasts, only the invasive subpopulation showed this pattern, which could help explain the higher rates of adverse outcomes in these pregnancies. In future experiments, this relationship will be further examined at a functional level in cultured human trophoblasts.

Chemical fingerprinting of naphthenic acids and oil sands process waters-A review of analytical methods for environmental samples

This article provides a review of the routine methods currently utilized for total naphthenic acid analyses. There is a growing need to develop chemical methods that can selectively distinguish compounds found within industrially derived oil sands process affected waters (OSPW) from those derived from the natural weathering of oil sands deposits. Attention is thus given to the characterization of other OSPW components such as oil sands polar organic compounds, PAHs, and heavy metals along with characterization of chemical additives such as polyacrylamide polymers and trace levels of boron species. Environmental samples discussed cover the following matrices: OSPW containments, on-lease interceptor well systems, on- and off-lease groundwater, and river and lake surface waters. There are diverse ranges of methods available for analyses of total naphthenic acids. However, there is a need for inter-laboratory studies to compare their accuracy and precision for routine analyses. Recent advances in high- and medium-resolution mass spectrometry, concomitant with comprehensive mass spectrometry techniques following multi-dimensional chromatography or ion-mobility separations, have allowed for the speciation of monocarboxylic naphthenic acids along with a wide range of other species including humics. The distributions of oil sands polar organic compounds, particularly the sulphur containing species (i.e., OxS and OxS2) may allow for distinguishing sources of OSPW. The ratios of oxygen- (i.e., Ox) and nitrogen-containing species (i.e., NOx, and N2Ox) are useful for differentiating organic components derived from OSPW from natural components found within receiving waters. Synchronous fluorescence spectroscopy also provides a powerful screening technique capable of quickly detecting the presence of aromatic organic acids contained within oil sands naphthenic acid mixtures. Synchronous fluorescence spectroscopy provides diagnostic profiles for OSPW and potentially impacted groundwater that can be compared against reference groundwater and surface water samples. Novel applications of X-ray absorption near edge spectroscopy (XANES) are emerging for speciation of sulphur-containing species (both organic and inorganic components) as well as industrially derived boron-containing species. There is strong potential for an environmental forensics application of XANES for chemical fingerprinting of weathered sulphur-containing species and industrial additives in OSPW.