scholarly journals Regulation and roles of Ca2+ stores in human sperm

Reproduction ◽  
2015 ◽  
Vol 150 (2) ◽  
pp. R65-R76 ◽  
Author(s):  
Joao Correia ◽  
Francesco Michelangeli ◽  
Stephen Publicover
Keyword(s):  
Plasma Membrane ◽  
Ion Channel ◽  
Regulatory Mechanism ◽  
Human Sperm ◽  
Good Evidence ◽  
Current Understanding ◽  
Sperm Function ◽  
Mammalian Sperm ◽  
Intracellular Organelles

[Ca2+]isignalling is a key regulatory mechanism in sperm function. In mammalian sperm the Ca2+-permeable plasma membrane ion channel CatSper is central to [Ca2+]isignalling, but there is good evidence that Ca2+stored in intracellular organelles is also functionally important. Here we briefly review the current understanding of the diversity of Ca2+stores and the mechanisms for the regulation of their activity. We then consider the evidence for the involvement of these stores in [Ca2+]isignalling in mammalian (primarily human) sperm, the agonists that may activate these stores and their role in control of sperm function. Finally we consider the evidence that membrane Ca2+channels and stored Ca2+may play discrete roles in the regulation of sperm activities and propose a mechanism by which these different components of the sperm Ca2+-signalling apparatus may interact to generate complex and spatially diverse [Ca2+]isignals.

scholarly journals Glutathione S-Transferases Play a Crucial Role in Mitochondrial Function, Plasma Membrane Stability and Oxidative Regulation of Mammalian Sperm

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 100 ◽  
Author(s):  
Marc Llavanera ◽  
Ariadna Delgado-Bermúdez ◽  
Samuel Olives ◽  
Yentel Mateo-Otero ◽  
Sandra Recuero ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Mitochondrial Function ◽  
Sperm Quality ◽  
Mammalian Species ◽  
Membrane Stability ◽  
Sperm Function ◽  
Cell Protection ◽  
Mammalian Sperm ◽  
Boar Sperm ◽  
Glutathione S Transferases

Glutathione S-transferases (GSTs) are essential sperm antioxidant enzymes involved in cell protection against oxidative stress and toxic chemicals, preserving sperm function and fertilising ability. Artificial insemination (AI) in pigs is commonly carried out through the use of liquid-stored semen at 17 °C, which not only reduces sperm metabolic activity but also sperm quality and AI-farrowing rates within the 72 h of storage. While one may reasonably suggest that such enzymes are implicated in the physiology and maintenance of mammalian sperm function during liquid-storage, no previous studies conducted on any species have addressed this hypothesis. Therefore, the objective of the present work was to characterise the presence and function of sperm GSTs in mammalian sperm, using the pig as a model. In this regard, inhibition of such enzymes by ethacrynic acid (EA) during semen storage at 17 °C was performed to evaluate the effects of GSTs in liquid-preserved boar sperm by flow cytometry, immunofluorescence, and immunoblotting analysis. The results of this study have shown, for the first time in mammalian species, that the inhibition of GSTs reduces sperm quality and functionality parameters during their storage at 17 °C. These findings highlight the key role of such enzymes, especially preserving mitochondrial function and maintaining plasma membrane stability. In addition, this study has identified and localised GSTM3 in the tail and equatorial subdomain of the head of boar sperm. Finally, this study has set grounds for future investigations testing supplementation of semen extenders with GSTs, as this may improve fertility outcomes of swine AIs.

Type 1 angiotensin II receptors in rat and human sperm

1995 ◽  
Vol 144 (2) ◽  
pp. 369-378 ◽  
Author(s):  
G P Vinson ◽  
J R Puddefoot ◽  
M M Ho ◽  
S Barker ◽  
J Mehta ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Reproductive Tract ◽  
Human Sperm ◽  
At1 Receptor ◽  
Seminiferous Tubules ◽  
Sperm Function ◽  
Motile Sperm ◽  
Physiological Factors ◽  
Mammalian Sperm

Abstract The physiological factors which induce and maintain mammalian sperm maturation and motility generally remain unclear, although several agents are known to be involved. We describe here the application of immunocytochemical and immunoblotting methods to identify the angiotensin II type 1 (AT1) receptor in the tails of ejaculated rat and human sperm. Motility data on stimulated and unstimulated sperm from volunteers and patients attending fertility clinics showed that angiotensin II may increase both the percentage of motile sperm and their linear velocity, while the specific AT1 receptor antagonist DuP753 inhibited the action of angiotensin II on the percentage of motile sperm. In rat seminiferous tubules, AT1 receptors were present in primary spermatogonia and in spermatid tails, but immunoreactivity was not seen in sperm contained in caput or cauda epididymis, showing that AT1 receptor function is regulated during transit through the reproductive tract. Since local tissue reninangiotensin systems are present in both male and female tracts, the data suggest that angiotensin II has a role in the maintenance of sperm function and fertility. Journal of Endocrinology (1995) 144, 369–

scholarly journals Three pools of plasma membrane cholesterol and their relation to cholesterol homeostasis

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Akash Das ◽  
Michael S Brown ◽  
Donald D Anderson ◽  
Joseph L Goldstein ◽  
Arun Radhakrishnan
Keyword(s):  
Plasma Membrane ◽  
Regulatory Mechanism ◽  
Low Density Lipoprotein ◽  
Human Fibroblasts ◽  
Density Lipoprotein ◽  
Cholesterol Homeostasis ◽  
Mutant Form ◽  
Perfringolysin O ◽  
Cholesterol Levels ◽  
Plasma Membrane Cholesterol

When human fibroblasts take up plasma low density lipoprotein (LDL), its cholesterol is liberated in lysosomes and eventually reaches the endoplasmic reticulum (ER) where it inhibits cholesterol synthesis by blocking activation of SREBPs. This feedback protects against cholesterol overaccumulation in the plasma membrane (PM). But how does ER know whether PM is saturated with cholesterol? In this study, we define three pools of PM cholesterol: (1) a pool accessible to bind 125I-PFO*, a mutant form of bacterial Perfringolysin O, which binds cholesterol in membranes; (2) a sphingomyelin(SM)-sequestered pool that binds 125I-PFO* only after SM is destroyed by sphingomyelinase; and (3) a residual pool that does not bind 125I-PFO* even after sphingomyelinase treatment. When LDL-derived cholesterol leaves lysosomes, it expands PM's PFO-accessible pool and, after a short lag, it also increases the ER's PFO-accessible regulatory pool. This regulatory mechanism allows cells to ensure optimal cholesterol levels in PM while avoiding cholesterol overaccumulation.

Ionic control of sperm function

1995 ◽  
Vol 7 (4) ◽  
pp. 905 ◽  
Author(s):  
LR Fraser
Keyword(s):  
Ionic Composition ◽  
Ion Fluxes ◽  
Sperm Function ◽  
Considerable Evidence ◽  
Functional Potential ◽  
Mammalian Sperm ◽  
Acrosomal Exocytosis ◽  
Extracellular Environment

Successful sperm function leads to fertilization. It is dependent on the extracellular environment, especially the array and concentration of various ions. Considerable evidence indicates that this is because of consequent effects on the intracellular ionic composition. Although both cations and anions undoubtedly play a role in a modulating sperm function, most of the evidence currently available concerns cations. Therefore, this review will concentrate on cations, focussing on Ca2+, Na+, K+ and H+. Their requirements for successful capacitation (mammalian sperm) and acrosomal exocytosis (both invertebrate and mammalian sperm) will be considered. In particular, the mechanisms which may control ion fluxes, leading to changes in the intracellular ionic composition and subsequently to changes in sperm functional potential, will be addressed.

Ketamine inhibits human sperm function by Ca2+-related mechanism

2016 ◽  
Vol 478 (1) ◽  
pp. 501-506 ◽  
Author(s):  
Yuanqiao He ◽  
Qianxing Zou ◽  
Bingda Li ◽  
Houyang Chen ◽  
Xiaohong Du ◽  
...  
Keyword(s):  
Human Sperm ◽  
Sperm Function

scholarly journals The endosomal transcriptional regulator RNF11 integrates degradation and transport of EGFR

2016 ◽  
Vol 215 (4) ◽  
pp. 543-558 ◽  
Author(s):  
Sandra Scharaw ◽  
Murat Iskar ◽  
Alessandro Ori ◽  
Gaelle Boncompain ◽  
Vibor Laketa ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Egf Receptor ◽  
Regulatory Mechanism ◽  
Transcriptional Regulator ◽  
Transport Efficiency ◽  
Early Endosomes ◽  
Epidermal Growth ◽  
Partial Degradation ◽  
Stimulation Of

Stimulation of cells with epidermal growth factor (EGF) induces internalization and partial degradation of the EGF receptor (EGFR) by the endo-lysosomal pathway. For continuous cell functioning, EGFR plasma membrane levels are maintained by transporting newly synthesized EGFRs to the cell surface. The regulation of this process is largely unknown. In this study, we find that EGF stimulation specifically increases the transport efficiency of newly synthesized EGFRs from the endoplasmic reticulum to the plasma membrane. This coincides with an up-regulation of the inner coat protein complex II (COPII) components SEC23B, SEC24B, and SEC24D, which we show to be specifically required for EGFR transport. Up-regulation of these COPII components requires the transcriptional regulator RNF11, which localizes to early endosomes and appears additionally in the cell nucleus upon continuous EGF stimulation. Collectively, our work identifies a new regulatory mechanism that integrates the degradation and transport of EGFR in order to maintain its physiological levels at the plasma membrane.

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