Control of APN/CD13 and NEP/CD10 on sperm motility

Aminopeptidase N (APN/CD13) and neutral endopeptidase (NEP/CD10) are enzymes present in human sperm cells and involved in regulation of sperm motility of noncapacitated spermatozoa. We investigated the involvement of APN/CD13 and NEP/CD10 in motility and in kinematic parameters of human capacitated spermatozoa. Sperm cells isolated by a discontinuous Percoll gradient (40%–80%) followed up by swim-up techniques were incubated with the APN/CD13-specific inhibitor, leuhistin (100 μmol L−1), and the NEP/CD10-specific inhibitor, thiorphan (1 μmol L−1). The complete inhibition of both APN/CD13 and NEP/CD10 improved sperm motility. Spermatozoa incubated with the APN/CD13-specific inhibitor leuhistin showed asymmetrical trajectories, whereas sperm trajectories were more regular after treatment with the NEP/CD10-specific inhibitor thiorphan. In conclusion, APN/CD13 and NEP/CD10 modulate the motility of capacitated spermatozoa, although each of the enzymes seems to participate in the control of different aspects of sperm motility. Therefore, both inhibitors may be useful for sperm activation at different functional stages of spermatozoa.Peer reviewe

Nobiletin-induced partial abrogation of deleterious effects of AKT inhibition on preimplantation bovine embryo development in vitro†

16 Pág. Departamento de Reproducción Animal​ (INIA)During preimplantational embryo development, PI3K/AKT regulates cell proliferation and differentiation and nobiletin modulates this pathway to promote cell survival. Therefore, we aimed to establish whether, when the AKT cascade is inhibited using inhibitors III and IV, nobiletin supplementation to in vitro culture media during the minor (2- to 8-cell stage, MNEGA) or major (8- to 16-cell stage, MJEGA) phases of EGA is able to modulate the development and quality of bovine embryos. In vitro zygotes were cultured during MNEGA or MJEGA phase in SOF + 5% FCS or supplemented with: 15 μM AKT-InhIII; 10 μM AKT-InhIV; 10 μM nobiletin; nobiletin + AKT-InhIII; nobiletin + AKT-InhIV; 0.03% DMSO. Embryo development was lower in treatments with AKT inhibitors, while combination of nobiletin with AKT inhibitors was able to recover their adverse developmental effect and also increase blastocyst cell number. The mRNA abundance of GPX1, NFE2L2, and POU5F1 was partially increased in 8- and 16-cell embryos from nobiletin with AKT inhibitors. Besides, nobiletin increased the p-rpS6 level whether or not AKT inhibitors were present. In conclusion, nobiletin promotes bovine embryo development and quality and partially recovers the adverse developmental effect of AKT inhibitors, which infers that nobiletin probably uses another signaling cascade that PI3K/AKT during early embryo development in bovine.This work was funded by the Spanish Ministry of Science and Innovation (PID2019-111641RB-I00 to DR and RTI2018-093548-B-I00 to AG-A). YNC was supported by a predoctoral fellowship from the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (Convocatoria abierta 2017, SENESCYT-Ecuador).Peer reviewe

BIASED AGONISM OF THREE DIFFERENT CANNABINOID RECEPTOR AGONISTS IN MOUSE BRAIN CORTEX

Cannabinoid receptors are able to couple to different families of G-proteins when activated by an agonist drug. It has been suggested that different intracellular responses may be activated depending on the ligand. The goal of the present study was to characterize the pattern of G protein subunit stimulation triggered by three different cannabinoid ligands, THC, WIN55212-2 and ACEA in mouse brain cortex.Stimulation of the [35S]GTPS binding coupled to specific immunoprecipitation with antibodies against different subtypes of G proteins (Gαi1, Gαi2, Gαi3, Gαo, Gαz, Gαs, Gαq/11, and Gα12/13), in the presence of Δ9-THC, WIN55212-2 and ACEA (submaximal concentration 10 µM) was determined by Scintillation Proximity Assay (SPA) technique in mouse cortex of wild type, CB1 knock-out, CB2 knock-out and CB1/CB2 double knock-out mice. Results show that, in mouse brain cortex, cannabinoid agonists are able to significantly stimulate not only the classical inhibitory Gαi/o subunits but also other G subunits like Gαz, Gαq/11, and Gα12/13. Moreover, the specific pattern of G protein subunit activation is different depending on the ligand. In conclusion, our results demonstrate that, in mice brain native tissue, different exogenous cannabinoid ligands are able to selectively activate different inhibitory and non-inhibitory Gα protein subtypes, through the activation of CB1 and/or CB2 receptors. Results of the present study may help to understand the specific molecular pathways involved in the pharmacological effects of cannabinoid-derived drugs

Differential hepatoprotective role of the cannabinoid CB1 and CB2 receptors in paracetamol-induced liver injury.

Protective mechanisms of the endogenous cannabinoid system against drug-induced liver injury (DILI) are actively being investigated regarding the differential regulatory role of the cannabinoid CB1 and CB2 receptors in liver fibrogenesis and inflammation. The 2-arachidonoylglycerol (2-AG)-related signalling receptors and enzymatic machinery, and inflammatory/fibrogenic factors were investigated in the liver of a mouse model of hepatotoxicity induced by acute and repeated overdoses (750 mg·kg-1 ·day-1 ) of paracetamol (acetaminophen), previously treated with selective CB1 (ACEA) and CB2 (JWH015) agonists (10 mg·kg-1 ), or lacking CB1 and CB2 receptors. Acute paracetamol increased the expression of CB2 , ABHD6 and COX-2, while repeated paracetamol increased that of CB1 and COX-2 and decreased that of DAGLβ. Both acute paracetamol and repeated paracetamol decreased the liver content of acylglycerols (2-AG, 2-LG and 2-OG). Human liver samples from a patient suffering APAP hepatotoxicity confirmed CB1 and CB2 increments. Acute paracetamol-exposed CB2 KO mice had higher expression of the fibrogenic αSMA and the cytokine IL-6 and lower apoptotic cleaved caspase 3. CB1 deficiency enhanced the repeated APAP-induced increases in αSMA and cleaved caspase 3 and blocked those of CYP2E1, TNF-α, the chemokine CCL2 and the circulating γ-glutamyltransferase (γGT). Although JWH015 reduced the expression of αSMA and TNF-α in acute paracetamol, ACEA increased the expression of cleaved caspase 3 and CCL2 in repeated paracetamol. The differential role of CB1 versus CB2 receptors on inflammatory/fibrogenic factors related to paracetamol-induced hepatotoxicity should be considered for designing alternative therapies against DILI