Reproductive biology: Progesterone's gateway into sperm.
ABSTRACT The hormone progesterone rapidly activates intracellular signalling in human sperm, regulating key aspects of their physiology. An ion channel unique to the sperm tail seems to relay progesterone's signal. See Letters p.382 & p.387
SourceAvailable from: Woo-Sung Kwon[Show abstract] [Hide abstract]
ABSTRACT: Male infertility refers to the inability of a man to achieve a pregnancy in a fertile female. In more than one-third of case, infertility arises due to male factor. Therefore, developing strategies for the diagnosis and prognosis of male infertility is critical. Simultaneously, a satisfactory model for the cellular mechanisms that regulate normal sperm function must be established. In this regard, tyrosine phosphorylation is one of the most common mechanisms through which several signal transduction pathways are adjusted in spermatozoa. It regulates the various aspects of sperm function for example, motility, hyperactivation, capacitation, the acrosome reaction, fertilization and beyond. Several recent large-scale studies have identified the proteins that are phosphorylated in spermatozoa to acquire fertilization competence. However, most of these studies are basal and have not presented an overall mechanism through which tyrosine phosphorylation regulates male infertility. In this review, we focus of this mechanism, discussing most of the tyrosine-phosphorylated proteins in spermatozoa that have been identified to date. We categorized tyrosine-phosphorylated proteins in spermatozoa that regulate male infertility using MedScan Reader (v5.0) and Pathway Studio (v9.0).Journal of Proteome Research 09/2014; 13(11):4505-4517. DOI:10.1021/pr500524p · 5.06 Impact Factor
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ABSTRACT: Calcium ion is a secondary messenger of mammalian spermatozoa. The dynamic change of its concentration plays a vital role in the process of sperm motility, capacitation, acrosome and fertilization. Progesterone released by the cumulus cells, as a potent stimulator of fertilization, can activate the calcium channels on the plasma membrane, which in turn triggers the dynamic change of intracellular calcium concentration. In this paper, a mathematical model of calcium dynamic response in mammalian spermatozoa induced by progesterone is proposed and numerical simulation of the dynamic model is conducted. The results show that the dynamic response of calcium concentration predicted by the model is in accordance with experimental evidence. The proposed dynamic model can be used to explain the phenomena observed in the experiments and predict new phenomena to be revealed by experimental investigations, which will provide the basis to quantitatively investigate the fluid mechanics and biochemistry for the sperm motility induced by progesterone.Journal of Theoretical Biology 03/2014; DOI:10.1016/j.jtbi.2014.02.026 · 2.35 Impact Factor
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ABSTRACT: Spermatozoon is the male gamete and its main function is to fertilize the oocyte. When ejaculation occurs, this cell is immature and therefore cannot perform its function. When it contacts the female reproductive tract, the sperm undergoes capacitation. This process is characterized by biochemical and functional changes. The acrosome reaction is the last process for fertilization and it is characterized by the release of proteolytic enzymes which hydrolyze the zona pellucida. All of these processes depend of signaling pathways. Most of the signaling pathways described for somatic cells have been identified in the sperm, but their effects are not completely known. In this review the main signaling pathways of sperm are described, including PPP1CC2, cAMP/PKA, phospholipase C, PI3K‐AKT and ROS.Revista Internacional de Andrología 07/2014; DOI:10.1016/j.androl.2014.04.006 · 0.22 Impact Factor