Department of Animal Reproduction, College of Veterinary Medicine and Animal Science, University of Sao Paulo, Sao Paulo, Brazil.
Published: February 2023
AI Article Synopsis
Article Abstract
The first cellular differentiation event in the pre-implantation embryo results in the trophectoderm (TE) and the inner cell mass (ICM). A second event occurs in the latter, resulting in the epiblast and the primitive endoderm (PE). This second differentiation is still not fully characterized in bovine development, although it is likely to involve FGF signalling. Thus, in this study, we tested the hypothesis that stimulation or inhibition of the FGF pathway during bovine embryo in vitro culture would only interfere with PE differentiation if maintained until later blastocyst stages. At first, we characterized the expression of PE marker SOX17 at different blastocyst stages. Then, we treated in vitro produced embryos during different windows of time: days 5.0-7.0 (D5-D7), D7-D9, and D5-D9 with 1 μg/ml FGF4 and 1 μg/ml heparin or 1 mM FGFR inhibitor, AZD4547. We observed that the SOX17-positive cell number only increases in late-stage blastocysts compared to early stages. Treatment of embryos with FGF4 did not change the number of SOX17-positive cells, while inhibition of FGFR signalling reduced SOX17-positive cells from D5-D7 and completely ablated SOX17 expression when kept until D9. In conclusion, FGFR inhibition repressed PE differentiation in bovine embryos at all time points, although stimulation with FGF4 did not interfere with PE cell numbers.
Background: Previously we found that increasing fibroblast growth factor (FGF) signaling in the neural crest cells within the frontonasal process (FNP) of the chicken embryo caused dysmorphology that was correlated with reduced proliferation, disrupted cellular orientation, and lower MAPK activation but no change in PLCy and PI3K activation. This suggests RTK signaling may drive craniofacial morphogenesis through specific downstream effectors that affect cellular activities. In this study we inhibited three downstream branches of RTK signaling to determine their role in regulating cellular activities and how these changes affect morphogenesis of the FNP.
State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, 21 Sassoon Road, Pokfulam 999077, Hong Kong, China; Department of Medicine, School of Clinical Medicine, The University of Hong Kong, 21 Sassoon Road, Pokfulam 999077, Hong Kong, China; Department of Pharmacology and Pharmacy, The University of Hong Kong, 21 Sassoon Road, Pokfulam 999077, Hong Kong, China. Electronic address:
β-Klotho (KLB), a type I transmembrane protein, serves as an obligate co-receptor determining the tissue-specific actions of endocrine fibroblast growth factors (FGFs). Despite accumulative evidence suggesting the occurrence of N-glycosylation in the KLB protein, the precise N-glycosites, glycoforms, and the impacts of N-glycosylation on the expression and function of the KLB protein remain unexplored. Employing a mass spectrometry-based approach, a total of 12 N-glycosites displaying heterogeneous site occupancy and glycoforms were identified within the extracellular region of the recombinant human KLB protein.
The formation of the vertebrate body involves the coordinated production of trunk tissues from progenitors located in the posterior of the embryo. Although in vitro models using pluripotent stem cells replicate aspects of this process, they lack crucial components, most notably the notochord-a defining feature of chordates that patterns surrounding tissues. Consequently, cell types dependent on notochord signals are absent from current models of human trunk formation.
Objective: Epithelial-mesenchymal transition (EMT) of alveolar epithelial cells is an important mechanism for the onset and development of broncho-pulmonary dysplasia (BPD).The role of FGF-2 in BPD is currently unclear. The aim of our study is to investigate the expression of FGF-2 in lung tissue of BPD mice, to further clarify the effect of FGF-2 on EMT in alveolar epithelial cells and to actively search for possible signaling pathways.
Cardiac development is a complex developmental process. The early cardiac straight tube is composed of an external myocardial layer and an internal endocardial lining. Soon after rightward looping, the embryonic heart becomes externally covered by a new epithelial lining, the embryonic epicardium.
