Adding cholesterol to the stallion sperm plasma membrane improves cryosurvival

Moore, Amanda; Squires, E.L.; Graham, James K.

doi:10.1016/j.cryobiol.2005.07.004

Cited by 200 publications

(158 citation statements)

References 23 publications

Supporting

Mentioning

115

Contrasting

Unclassified

Order By: Relevance

“…Translocation of the cargo through the lipid bilayer by the process of flip-flop diffusion would face an energy barrier, and thus could be expected to be slowed by lowering the temperature. Additionally, peptide flip-flop may also be drastically reduced due to the fluid-gel transition of the mammalian plasma membrane at temperatures below 20°C (30,50). Future studies to clarify the molecular mechanism of cargo translocation across the plasma membrane will help elucidate this issue.…”

Section: Discussionmentioning

confidence: 99%

Myristoyl-Based Transport of Peptides into Living Cells

et al. 2007

View full text Add to dashboard Cite

Translocation of membrane impermeant molecules to the interior of living cells is a necessity for many biochemical investigations. Myristoylation was studied as a means to introduce peptides into living cells. Uptake of a myristoylated, fluorescent peptide was efficient in the B lymphocyte cell line BA/F3. In contrast, this cell line was resistant to peptide uptake using a cell penetrating peptide derived from the TAT protein. In BA/F3 cells, membrane association was shown to be rapid reaching a maximum within 30 minutes. Cellular uptake of the peptide lagged the membrane association, but occurred within a similar time frame. Experiments performed at 37°C vs. 4°C demonstrated profound temperature dependence in the cellular uptake of myristoylated cargo. Myristoylated peptides with either positive or negative charge were shown to load efficiently. In contrast to TAT-conjugated cargo, pyrenebutyrate did not enhance cellular uptake of the myristoylated peptide. The myristoylated peptide did not adversely affect cell viability at concentrations up to 100 μM. This assessment of myristoyl-based transport provides fundamental data needed in understanding the intracellular delivery of myristoylated peptide cargoes for cellbased biochemical studies.

show abstract

Section: Discussionmentioning

confidence: 99%

Myristoyl-Based Transport of Peptides into Living Cells

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Similar studies were done with stallion sperm. Moore et al (2005) reported a beneficial effect of CLC at a level of 1.5 mg/ml when added to stallion sperm prior to freezing.…”

Section: Advances In Freezing Semenmentioning

confidence: 99%

Integration of future biotechnologies into the equine industry

Squires¹

2005

Animal Reproduction Science

View full text Add to dashboard Cite

There has and will continue to be reproductive techniques available that have a positive impact upon the equine breeding industry. This review focuses on semen technologies that have been developed or are in the process of being developed. The use of fluorescent dyes and flow cytometry has provided the researcher and clinician with powerful tools to evaluate several sperm attributes. These procedures have been utilized to evaluate sperm viability, acrosome status, mitochondrial status, DNA integrity and stages of capacitation. Flow cytometry allows several sperm attributes to be evaluated on thousands of spermatozoa in a matter of seconds. Development of procedures for insemination of mares with relatively small numbers of spermatozoa has the potential to change how stallions and their semen are managed. This review discusses the use of insemination of fresh, frozen and sex-sorted spermatozoa in relatively small numbers compared with conventional insemination technologies. The recent acceptance of frozen-thawed semen by many of the major breed registries has stimulated an increase in research on frozen semen. Many of the studies have focused on identifying damage during the freezing and thawing process. Numerous studies also have been conducted to modify freezing extenders so that the sperm are protected during the freezing and thawing process. The production of in vitro-produced embryos is extremely limited in the horse due to the failure of in vitro fertilization. However, intracytoplasmic sperm injection (ICSI) has been used for the production of foals from stallions that have less than typical sperm numbers or from stallions that have died and a limited quantity of frozen semen is available. This technique has been used by several laboratories to produce embryos in vitro. The breeder and veterinarian now have access to techniques that allow assessment of semen quality, improvement of procedures for freezing and thawing and insemination of mares with fewer numbers of spermatozoa. It is likely that the next decade will also produce tremendous advances in semen technologies that can be utilized in the horse industry.

show abstract

“…The addition of certain lipid mixtures, including cholesterol (Moore et al 2005), appeared to be the best way to prevent deterioration, and more recently, cholesterol-loaded cyclodextrins (CLC; molecules with specific affinity for free sterols (Shadan et al 2004)) have been used (Moce et al 2010, Serin et al 2011. Such approaches led to increased cellular levels of cholesterol by monomeric transfer of these lipids from their carriers and spermatozoa pre-loaded with cholesterol are more stable during freeze-thawing than those that have not been pre-loaded ( (2011) demonstrated that cholesterol can be oxidised during capacitation and that these oxidation products are preferentially adsorbed by albumin (the cholesterol depletory in IVF media).…”

Section: Stabilisation Of the Sperm Surface With Cholesterol And Othementioning

confidence: 99%

Sperm surface changes and physiological consequences induced by sperm handling and storage

2011

View full text Add to dashboard Cite

Spermatozoa interact with their immediate environment and this contact remodels the sperm surface in preparation for fertilisation. These fundamental membrane changes will be critically covered in this review with special emphasis on the very specific surface destabilisation event, capacitation. This process involves very subtle and intricate modifications of the sperm membrane including removal of suppression (decapacitation) factors and changes in the lateral organisation of the proteins and lipids of the sperm surface. Processing of sperm for assisted reproduction (storage, sex-sorting, etc.) subjects spermatozoa to numerous stressors, and it is possible that this processing overrides such delicate processes resulting in sperm instability and cell damage. To improve sperm quality, novel mechanisms must be used to stabilise the sperm surface during handling. In this review, different types of membrane stress are considered, as well as novel surface manipulation methods to improve sperm stability.

show abstract

Adding cholesterol to the stallion sperm plasma membrane improves cryosurvival

Cited by 200 publications

References 23 publications

Myristoyl-Based Transport of Peptides into Living Cells

Myristoyl-Based Transport of Peptides into Living Cells

Integration of future biotechnologies into the equine industry

Sperm surface changes and physiological consequences induced by sperm handling and storage

Contact Info

Product

Resources

About