Role of complement regulatory proteins CD46, CD55 and CD59 in reproduction

Komrsková

2021

IJMS

In mammals, integrins are heterodimeric transmembrane glycoproteins that represent a large group of cell adhesion receptors involved in cell–cell, cell–extracellular matrix, and cell–pathogen interactions. Integrin receptors are an important part of signalization pathways and have an ability to transmit signals into and out of cells and participate in cell activation. In addition to somatic cells, integrins have also been detected on germ cells and are known to play a crucial role in complex gamete-specific physiological events, resulting in sperm-oocyte fusion. The main aim of this review is to summarize the current knowledge on integrins in reproduction and deliver novel perspectives and graphical interpretations presenting integrin subunits localization and their dynamic relocation during sperm maturation in comparison to the oocyte. A significant part of this review is devoted to discussing the existing view of the role of integrins during sperm migration through the female reproductive tract; oviductal reservoir formation; sperm maturation processes ensuing capacitation and the acrosome reaction, and their direct and indirect involvement in gamete membrane adhesion and fusion leading to fertilization.

Section: The Role Of Integrins In Membrane Reorganization and Stabilitysupporting

confidence: 86%

Role of Integrins in Sperm Activation and Fertilization

Merc

Komrsková

2021

IJMS

“…Interestingly, Tas1r3 expression in testis was~two-fold higher than that in the tongue where this receptor was originally detected. This expression pattern of Tas1r3 resembles the one of Cd46 [27], which was used as a positive control due to its abundant expression in testes and its well described role in fertilization of mammals especially rodents [7,8,28,29]. The result of mRNA gene expression ( Figure 1) suggests that the mTAS1R3 receptor, similar to CD46, is expressed in testes including male germ cells; therefore, it could be predicted to be involved in sperm-related fertilization strategies.…”

Section: The Analysis Of Mrna Expression Of Tas1r3 Gene In Mouse Tissuementioning

confidence: 87%

The Role of Taste Receptor mTAS1R3 in Chemical Communication of Gametes

Otčenášková

Valaskova

et al. 2020

IJMS

Self Cite

Fertilization is a multiple step process leading to the fusion of female and male gametes and the formation of a zygote. Besides direct gamete membrane interaction via binding receptors localized on both oocyte and sperm surface, fertilization also involves gamete communication via chemical molecules triggering various signaling pathways. This work focuses on a mouse taste receptor, mTAS1R3, encoded by the Tas1r3 gene, as a potential receptor mediating chemical communication between gametes using the C57BL/6J lab mouse strain. In order to specify the role of mTAS1R3, we aimed to characterize its precise localization in testis and sperm using super resolution microscopy. The testis cryo-section, acrosome-intact sperm released from cauda epididymis and sperm which underwent the acrosome reaction (AR) were evaluated. The mTAS1R3 receptor was detected in late spermatids where the acrosome was being formed and in the acrosomal cap of acrosome intact sperm. AR is triggered in mice during sperm maturation in the female reproductive tract and by passing through the egg surroundings such as cumulus oophorus cells. This AR onset is independent of the extracellular matrix of the oocyte called zona pellucida. After AR, the relocation of mTAS1R3 to the equatorial segment was observed and the receptor remained exposed to the outer surroundings of the female reproductive tract, where its physiological ligand, the amino acid L-glutamate, naturally occurs. Therefore, we targeted the possible interaction in vitro between the mTAS1R3 and L-glutamate as a part of chemical communication between sperm and egg and used an anti-mTAS1R3-specific antibody to block it. We detected that the acrosome reacted spermatozoa showed a chemotactic response in the presence of L-glutamate during and after the AR, and it is likely that mTAS1R3 acted as its mediator.

“…is a crucial step enabling sperm to become fusion competent. During AR, a dramatic reorganization of sperm head membranes occurs including fusion of plasma and outer acrosomal membranes, in order to release the acrosomal content leaving the sperm head surface covered with inner acrosomal membrane (IAM) exposing new proteins [30][31][32][33] . During this event, many of the membrane proteins originally locked in the acrosome relocate to the plasma membrane and different sperm head compartments, mainly to the equatorial segment.…”

mentioning

confidence: 99%

Expression and distribution of CD151 as a partner of alpha6 integrin in male germ cells

Jankovičová

Palenikova

et al. 2020

Sci Rep

The physiological importance of CD151 tetraspanin is known from somatic cells and its outside-in signalling through integrins was described. In male germ cells, two tetraspanins, CD9 and CD81, are involved in sperm-egg membrane fusion, and similarly to integrins, they occupy characteristic regions. We report here on a newly discovered presence of CD151 in sperm, and present its expression and distribution during spermatogenesis and sperm transition during the acrosome reaction. We traced CD151 gene and protein expression in testicular cell subpopulations, with strong enrichment in spermatogonia and spermatids. The testicular and epididymal localization pattern is designated to the sperm head primary fusion site called the equatorial segment and when compared to the acrosome vesicle status, CD151 was located into the inner acrosomal membrane overlying the nucleus. Moreover, we show CD151 interaction with α6 integrin subunit, which forms a dimer with β4 as a part of cisprotein interactions within sperm prior to gamete fusion. We used mammalian species with distinct sperm morphology and sperm maturation such as mouse and bull and compared the results with human. In conclusion, the delivered findings characterise CD151 as a novel sperm tetraspanin network member and provide knowledge on its physiology in male germ cells.CD151 belongs to the tetraspanin superfamily, these proteins participate in many biological processes such as growth control, intracellular signalling, cell adhesion, migration, motility 1-4 and they also take place in pathogenesis of some human diseases 5,6 . Tetraspanins create a scaffolding multiprotein network in the membrane that anchors other proteins into specific domains with precise functions and moreover, they are indispensable players in the mammalian fertilization process. Tetraspanin CD9 expressed on mouse eggs is considered as an essential molecule for successful gamete fusion 7-9 as well as tetraspanin CD81 which is also involved in fertilization 10,11 . Our previous studies concerning species-specific traits of CD9 and CD81 in mouse, bull and porcine gametes during their functional maturation and fertilization, suggested the active participation of tetraspanins in these events [11][12][13][14] . With the ability of tetraspanins being part of signalling cascades involving cytoskeleton 5,15,16 they also play a crucial role in the organization of functional membrane protein cluster domains called a tetraspanin web, which were also described in oocyte and recently in sperm. The integral part of the tetraspanin web are integrins and the presence of α3β1, α6β1 and α6β4 integrins was shown in sperm [17][18][19][20] . Importantly, in somatic cells, tetraspanin CD151 was found to play a key role in regulating the adhesion strengthening of integrin α6β1 21 . CD151 has previously been linked with human gamete fusion 22 , associates specifically with α3, α6 and α7 integrins 1,3,23 and links α3β1 and α6β1 integrins to other tetraspanins, including CD9 [24][25][26][27] . Based on that knowledge we p...