Background/Objectives: Choline plays an important role in maintaining normal cellular function and overall physiology. Endogenous choline availability depends on the synthesis of phosphatidylcholine via the phosphatidylethanolamine N-methyltransferase (PEMT) pathway. Expression of PEMT is influenced by estrogen, as its promoter contains multiple estrogen-responsive elements that enhance enzyme activity. How a low estrogenic condition like menopause influences choline's effect on the brain is not yet fully understood. Methods: In this pilot study, 20 women participated in two study days, with 1650 mg of oral choline bitartrate or a matching placebo administered three hours before a functional and structural magnetic resonance imaging (MRI) scan. Blood oxygen level dependent (BOLD) functional MRI scans were collected on each study day while subjects performed an N-back working memory task. Results: In this pilot study, no differences in working memory performance were observed, but decreased activation was found for the choline compared to the placebo during the 2-back compared to 0-back conditions in regions of the right temporal lobe (p < 0.001 voxel-level threshold, and p-FDR < 0.05 cluster-size threshold). When we seeded the right planum temporale to examine its functional connectivity with the rest of the brain, we found that choline modulated a large portion of the working memory network during the difficult memory load condition. Conclusions: These results in this pilot study illustrate the effect of choline on working memory-related brain activation and functional connectivity in postmenopausal women. We propose that choline may increase brain functional efficiency in low estrogenic conditions like menopause, but further studies are needed.
The early post-embryo transfer period lacks well-defined beta-human chorionic gonadotropin (hCG) thresholds to distinguish viable from non-viable pregnancies after frozen embryo transfer (FET). This study aimed to identify a day-14 post-FET hCG cutoff that predicts fetal heart tones (FHT) and live birth (LB), and to assess its utility in guiding decisions regarding continuation of progesterone support. A retrospective cohort study was conducted at a single academic center including 1681 single-embryo FETs from 2021 to 2023. Demographic, cycle, and embryologic variables were extracted from medical records. Serum hCG levels were measured 14 days post-FET. Receiver operating characteristic analyses identified optimal hCG thresholds for predicting FHT and LB. Outcomes were compared using appropriate parametric and nonparametric statistical tests. Overall, 59.0
Human pluripotent stem cells (hPSCs) exist in at least two distinct states of pluripotency: naïve and primed. While naïve hPSCs possess the unique ability to generate blastocyst-like structures, they are often genetically and epigenetically unstable, which compromises the quality and developmental potential of naïve hPSC-derived blastoids. This protocol presents an optimized human blastoid protocol through a transient resetting method that converts primed hPSCs into a naïve-like state, addressing the stability issues associated with long-term naïve hPSC maintenance. The approach is compatible with both feeder-free and feeder-based culture systems and demonstrates high efficiency in generating human blastoids directly from primed hPSCs. This advancement provides a more robust and reliable strategy for blastoid formation, circumventing the limitations of suboptimal naïve hPSC cultures.
Early embryonic development occurs in a low oxygen environment, and mitochondrial morphology and function are distinct in embryonic cells and pluripotent stem cells (PSC), which rely less on oxidative phosphorylation than differentiated cells. Oxidative phosphorylation increases with differentiation to trophoblast (TB) and this process is reversed by reprogramming of adult cells to pluripotency, but the influence of oxygen conditions on this process has not been characterized. When PSC were differentiated to trophoblast by treatment with BAP (BMP4, A83-01 and PD173074), cellular ATP concentrations increased equally in 5% and 20% oxygen conditions. Although oxygen conditions in culture altered transcripts encoding mitochondrial proteins, particularly by suppressing COX4l2 at 20% oxygen, there were no consistent differences in mitochondrial morphology in either cytotrophoblast (CTB) or syncytiotrophoblast (STB) cells with changing oxygen. These results suggest that TB adapt to maintain mitochondrial function at high and low oxygen during differentiation. In a previous study, iPSCs were derived from both control and early onset preeclampsia (EOPE) pregnancies and differentiated with BAP; high oxygen conditions impaired TB invasion only in cells from EOPE pregnancies. Here, the increase in ATP concentration with TB differentiation was less robust in EOPE cells, and cytochrome C and ATPase subunit transcripts differed between EOPE and control cells at high oxygen. However, investigation of mitochondrial morphology revealed no excess damage in EOPE-derived lines, and no difference in mitochondrial respiration was detected. Collectively, these data provide limited support for the hypothesis that intrinsic differences in mitochondria underlie poor TB invasion in EOPE.
