Asymmetric distribution of CRUMBS polarity complex proteins from compacted 8-cell to blastocyst stage during mouse preimplantation development

Embryo-Induced Changes in the Protein Profile of Bovine Oviductal Extracellular Vesicles

The study of early maternal-embryonic cross-talk remains one of the most challenging topics in reproductive biology. Understanding the physiological mechanisms involved in the interactions between the maternal reproductive tract and the developing embryo is essential for enhancing bovine reproductive efficiency. This complex communication starts within the oviduct, where the modulation of biological processes important for ensuring embryo quality is partially facilitated through extracellular vesicles (EVs). Utilizing a combination of in vivo and in vitro models this study had three main objectives: 1) to examine the protein cargo of EVs isolated from the oviductal fluid (OF) of cyclic and pregnant heifers to understand their role in maternal-embryonic communication in vivo; 2) to characterize the protein profile of EVs in conditioned medium (CM) resulting from the culture of oviductal explants alone (Exp) or in the presence of 8- to 16-cell stage embryos (Exp + Emb); and 3) to compare the protein cargo of EVs from Exp with EVs from cyclic heifers and EVs from Exp + Emb with EVs from pregnant heifers. Proteins were considered "identified" if detected in at least three out of five replicates and considered "exclusive" if detected in at least three out of five replicates within one group but absent in all samples of other groups. We identified 659 and 1476 proteins in the OF-EVs of cyclic and pregnant heifers, respectively. Among these, 644 proteins were identified in OF-EVs from both cyclic and pregnant heifers, and 40 proteins were exclusive to OF-EVs from the pregnant group. Within the 644 proteins identified in both groups, 31 were identified as differently abundant proteins (DAPs). In pregnant heifers, DAPs were mainly related to genome activation, DNA repair, embryonic cell differentiation, migration, and immune tolerance. In vitro, we identified 841 proteins in the CM-EVs from Exp alone, 613 from Exp + Emb, and 111 in the CM-EVs from Emb alone. In the qualitative analysis between the three in vitro groups, 81 proteins were identified in all groups, 452 were common to Exp and Exp + Emb, 17 were common to Exp and Emb, 5 were common to Exp + Emb and Emb, 4 were unique to Exp, 6 were unique to Exp + Emb, and none were unique to Emb. Proteins identified when there is an interaction between the oviduct and the embryo in vitro, corresponding to the Exp + Emb group, were associated with immune tolerance, structural activity, binding, and cytoskeletal regulation. In vivo and in vitro EVs exhibit distinct qualitative and quantitative protein contents, both when comparing EVs produced in the absence of an embryo (Cyclic and Exp) and those that have undergone embryo-oviduct interaction (Pregnant and Exp + Emb). The observed changes in the protein cargo of EVs due to maternal-embryonic communication in vivo and in vitro suggest that the interaction between the embryo and the maternal milieu initiates within the oviduct and is potentially facilitated by EVs and their protein contents.

Noninvasive autologous mitochondria transport improves the quality and developmental potential of oocytes from aged mice

OBJECTIVE

To establish an optimized autologous mitochondria transport technique for oocyte-aging rescue, which minimizes both the patient's pains and the damage to oocytes.

DESIGN

Experimental laboratory study.

SETTING

Laboratory.

ANIMAL(S)

Institute of Cancer Research mice.

INTERVENTION(S)

The murine umbilical cord mesenchymal stem cells were isolated from the female pup and cryopreserved. After the female aged, its germinal vesicle (GV) oocytes were collected and treated to weaken the zona pellucida. Its autologous umbilical cord mesenchymal stem cells were induced into granulosa cells (iGCs). The zona-weakened GV oocytes were aggregated with iGCs into iGC-oocyte complexes. Then, these complexes were cultured in growth-differentiation factor 9-containing media for 3 days. Next, they were subjected to in vitro maturation and fertilization. Presumptive zygotes were cultured for 24 hours, and the cleaved 2-cell embryos were selected for embryo transfer.

MAIN OUTCOME MEASURE(S)

The oocyte quality was determined by examining mitochondrial ultrastructure using transmission electron microscopy, the adenosine triphosphate content using a luminometer, and intracellular reactive oxygen species levels by confocal microscopy. The spindle organization in mature oocytes was examined by confocal microscopy. The developmental potential of oocytes was evaluated by monitoring the in vitro embryo development and the birth rate after embryo transfer.

RESULT(S)

Mitochondria migrated from iGCs into the GV oocyte via transzonal filopodia. The maturation rate, quality, and developmental potential of these oocytes were substantially increased. Furthermore, the birth rate after embryo transfer has been improved.

CONCLUSION(S)

This approach used noninvasive procedures to collect mitochondria donor cells and optimized mitochondria transfer manipulations; thus, it may have potential in ameliorating oocyte-aging-related subfertility.

Zeb1 modulates hematopoietic stem cell fates required for suppressing acute myeloid leukemia

Zeb1, a zinc finger E-box binding homeobox epithelial-mesenchymal transition (EMT) transcription factor, confers properties of "stemness," such as self-renewal, in cancer. Yet little is known about the function of Zeb1 in adult stem cells. Here, we used the hematopoietic system as a well-established paradigm of stem cell biology to evaluate Zeb1-mediated regulation of adult stem cells. We employed a conditional genetic approach using the Mx1-Cre system to specifically knock out (KO) Zeb1 in adult hematopoietic stem cells (HSCs) and their downstream progeny. Acute genetic deletion of Zeb1 led to rapid-onset thymic atrophy and apoptosis-driven loss of thymocytes and T cells. A profound cell-autonomous self-renewal defect and multilineage differentiation block were observed in Zeb1-KO HSCs. Loss of Zeb1 in HSCs activated transcriptional programs of deregulated HSC maintenance and multilineage differentiation genes and of cell polarity consisting of cytoskeleton-, lipid metabolism/lipid membrane-, and cell adhesion-related genes. Notably, epithelial cell adhesion molecule (EpCAM) expression was prodigiously upregulated in Zeb1-KO HSCs, which correlated with enhanced cell survival, diminished mitochondrial metabolism, ribosome biogenesis, and differentiation capacity and an activated transcriptomic signature associated with acute myeloid leukemia (AML) signaling. ZEB1 expression was downregulated in AML patients, and Zeb1 KO in the malignant counterparts of HSCs - leukemic stem cells (LSCs) - accelerated MLL-AF9- and Meis1a/Hoxa9-driven AML progression, implicating Zeb1 as a tumor suppressor in AML LSCs. Thus, Zeb1 acts as a transcriptional regulator in hematopoiesis, critically coordinating HSC self-renewal, apoptotic, and multilineage differentiation fates required to suppress leukemic potential in AML.

Research Progress on PATJ and Underlying Mechanisms Associated with Functional Outcomes After Stroke

Cell polarity is an intrinsic property of epithelial cells regulated by scaffold proteins. The CRB (crumbs) complex is known to play a predominant role in the dynamic cooperative network of polarity scaffold proteins. PATJ (PALS1-associated tight junction) is the core component in the CRB complex and has been highly conserved throughout evolution. PATJ is crucial to several important events in organisms' survival, including embryonic development, cell polarity, and barrier establishment. A recent study shows that PATJ plays an important role in functional outcomes of stroke. In this article, we elaborate on the biological structure and physiological functions of PATJ and explore the underlying mechanisms of PATJ genetic polymorphism that are associated with poor functional outcomes in ischemic stroke.