Serum progesterone and oxytocinase, and endometrial and luteal gene expression in pregnant, nonpregnant, oxytocin, carbetocin and meclofenamic acid treated mares.

Our objectives were to examine changes in endometrial and luteal gene expression during estrus, diestrus, pregnancy and treatments to induce luteolysis and putatively induce luteostasis. Groups were: Diestrus (DIEST), Estrus (ESTR), Pregnant (PREG), Oxytocin (OXY), Carbetocin (CARB), and Meclofenamic acid (MFA). Blood was obtained from day (D)12 to D15 for measurement of oxytocinase, also referred to as leucyl-cysteinyl aminopeptidase (LNPEP) and progesterone.

Endometrial and luteal gene expression of putative gene regulators of the equine maternal recognition of pregnancy.

Our understanding of the temporal changes in endometrial and luteal gene transcripts related to the actions of oxytocin and prostaglandin during early equine pregnancy is incomplete. Additionally, the role of oxytocinase, also known as Leucyl-cystinyl aminopeptidase (LNPEP), during early pregnancy in mares has not been previously investigated. Luteal and endometrial biopsies were obtained on Day (D)8, D10, D12 and D15 post-ovulation in pregnant (PREG) and diestrus (DIEST) mares for real-time qPCR.

Testis-Specific Isoform of Na/K-ATPase (ATP1A4) Interactome in Raft and Non-Raft Membrane Fractions from Capacitated Bovine Sperm.

The plasma membrane of sperm contains highly dynamic lipid microdomains (rafts), which house signaling proteins with a role in regulating capacitation. We reported that ATP1A4, the testis-specific isoform of Na/K-ATPase, interacted with caveolin-1, Src, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinases 1/2 (ERK1/2) in raft and non-raft domains of the plasma membrane of bovine sperm during capacitation. The objective of the present study was to use a proteomic approach to characterize the ATP1A4 interactome in rafts and non-rafts from capacitated bovine sperm.

Na/K-ATPase and Regulation of Sperm Function.

A standard bull breeding soundness evaluation (BBSE) identifies bulls with semen that is grossly abnormal. Nonetheless, semen samples classified as satisfactory based on these traditional approaches differ in fertility; perhaps there are submicroscopic differences in sperm characteristics affecting fertility. Therefore, a better understanding of molecular regulation of sperm function could promote development of novel, evidence-based approaches to predict male fertility.

Na/K-ATPase regulates bovine sperm capacitation through raft- and non-raft-mediated signaling mechanisms.

Highly dynamic lipid microdomains (rafts) in the sperm plasma membrane contain several signaling proteins that regulate sperm capacitation. Na/K-ATPase isoforms (testis-specific isoform ATP1A4 and ubiquitous isoform ATP1A1) are abundant in bovine sperm plasma membrane. We previously reported that incubation of bovine sperm with ouabain, a specific Na/K-ATPase ligand, induced tyrosine phosphorylation of several sperm proteins during capacitation.

The ubiquitous isoform of Na/K-ATPase (ATP1A1) regulates junctional proteins, connexin 43 and claudin 11 via Src-EGFR-ERK1/2-CREB pathway in rat Sertoli cells.

Interaction of Na/K-ATPase with its ligand ouabain has been implicated in the regulation of various biological processes. The objective was to investigate roles of Na/K-ATPase isoforms in formation and function of junctional complexes in Sertoli cells. Primary cultures of Sertoli cells were obtained by enzymatic digestion of 20-day-old rat testes and grown on Matrigel-coated dishes for 7 days.

Content of testis-specific isoform of Na/K-ATPase (ATP1A4) is increased during bovine sperm capacitation through translation in mitochondrial ribosomes.

Capacitation comprises a series of structural and functional modifications of sperm that confer fertilizing ability. We previously reported that the testis-specific isoform of Na/K-ATPase (ATP1A4) regulated bovine sperm capacitation through signaling mechanisms involving kinases. During subsequent investigations to elucidate mechanisms by which ATP1A4 regulates sperm capacitation, we observed that ATP1A4 was localised in both raft and non-raft fractions of the sperm plasma membrane and that its total content was increased in both membrane fractions during capacitation.

Proteins associated with critical sperm functions and sperm head shape are differentially expressed in morphologically abnormal bovine sperm induced by scrotal insulation.

Unlabelled: The objective was to investigate expression patterns of proteins in pyriform sperm, a common morphological abnormality in bull sperm. Ejaculates were collected from sexually mature Holstein bulls (n=3) twice weekly for 10 weeks (pre-thermal insult samples). Testicular temperature was elevated in all bulls by scrotal insulation for 72 consecutive hours during week 2.