Neurotransmitters, neuropeptides and calcium in oocyte maturation and early development

Abstract

A primary reason behind the high level of complexity we embody as multicellular organisms is a highly complex intracellular and intercellular communication system. As a result, the activities of multiple cell types and tissues can be modulated resulting in a specific physiological function. One of the key players in this communication process is extracellular signaling molecules that can act in autocrine, paracrine, and endocrine fashion to regulate distinct physiological responses. Neurotransmitters and neuropeptides are signaling molecules that renders long-range communication possible. In normal conditions, neurotransmitters are involved in normal responses such as development and normal physiological aspects; however, the dysregulation of neurotransmitters mediated signaling has been associated with several pathologies such as neurodegenerative, neurological, psychiatric disorders, and other pathologies. One of the interesting topics that is not yet fully explored is the connection between neuronal signaling and physiological changes during oocyte maturation and fertilization. Knowing the importance of Ca2+ signaling in these reproductive processes, our objective in this review is to highlight the link between the neuronal signals and the intracellular changes in calcium during oocyte maturation and embryogenesis. Calcium (Ca2+) is a ubiquitous intracellular mediator involved in various cellular functions such as releasing neurotransmitters from neurons, contraction of muscle cells, fertilization, and cell differentiation and morphogenesis. The multiple roles played by this ion in mediating signals can be primarily explained by its spatiotemporal dynamics that are kept tightly checked by mechanisms that control its entry through plasma membrane and its storage on intracellular stores. Given the large electrochemical gradient of the ion across the plasma membrane and intracellular stores, signals that can modulate Ca2+ entry channels or Ca2+ receptors in the stores will cause Ca2+ to be elevated in the cytosol and consequently activating downstream Ca2+-responsive proteins resulting in specific cellular responses. This review aims to provide an overview of the reported neurotransmitters and neuropeptides that participate in early stages of development and their association with Ca2+ signaling.

The Therapeutic and Diagnostic Potential of Phospholipase C Zeta, Oocyte Activation, and Calcium in Treating Human Infertility

“…The series of Ca 2+ oscillations that are seen in OA that are attributed to be the function of the “sperm factor” is believed to be the direct result of Ca 2+ release via (IP 3 -mediated reactions [ 10 , 15 , 28 , 43 , 44 , 45 ], and PLCs are a class of enzymes well characterised to be involved in the catabolism of phosphatidylinositol 4,5-bisphosphate (PIP 2 ) into IP 3 and diacylglycerol (DAG) [ 28 , 46 , 47 , 48 ]. PLCs have 13 known isoforms that can be classified based on function and structure and they are PLC beta (β1–4), PLC delta (δ1,3 and 4), PLC epsilon (ε), PLC eta (η1–2), PLC gamma (γ1–2), and PLC zeta (ζ) [ 28 , 47 , 49 , 50 , 51 , 52 ].…”

“…The Ca 2+ oscillation signals the start as a result of the disturbance of cytosolic Ca 2+ equilibrium. This disturbance occurs as a response to stimulatory signals that act on Ca 2+ receptors which are found either in the cytoplasmic membrane or ER (Ca 2 store) and will result in an increase in cytoplasmic Ca 2+ [ 15 ]. Coordinated calcium waves will be produced by internal Ca 2+ stores, where a sudden increase of Ca 2+ will induce more Ca 2+ release through a series of events as positive feedback [ 16 ], a process termed calcium-induced calcium release (CICR).…”

Applications of advances in mRNA-based platforms as therapeutics and diagnostics in reproductive technologies

“…To this degree, the control of mRNA degradation/translation status is major regulatory step, maintained both spatially and temporally, with specific regulatory factors exerting a critical role during early embryogenesis. Thus, such factors may also serve as important potential targets for RNA-based therapies (knockdown/expression as appropriate) (Teixeira and Lehmann, 2019;Alhajeri et al, 2022;Zhang et al, 2022). Further to maternal factors, Yuan et al (2023) reported that the paternal genome also exerts a significant influence during maternal RNA degradation (MRD) and ZGA in human early embryos, and mused whether the infertility of some patients may be attributable to defects of paternal contributors of human ZGA.…”

Effects of amylin on egg quality traits of hens during the early laying period

“…Tryptophan is not only an essential aminoacid for chickens, mainly used for protein synthesis, but also has various metabolic functions in the brain, such as the precursor of serotonin and melatonin (El-Slamoney et al, 2010;Khattak and Helmbrecht, 2019). Serotonin plays an important role in oocyte maturation, embryonic development, laying behavior, and improving intracellular Ca levels (Khattak and Helmbrecht, 2019;Alhajeri et al, 2022).…”