ABSTRACT
Macroautophagy (hereafter autophagy) is an evolutionarily highly conserved cellular process that participates in the maintenance of intracellular homeostasis through the degradation of most long-lived proteins and entire organelles. Autophagy participates in some reproductive events; however, there are not reports regarding the role of autophagy in the regulation of sperm physiology. Hence, the aim of this study was to investigate whether autophagy-related proteins are present and functionally active in human spermatozoa. Proteins related to autophagy/mitophagy process (LC3, Atg5, Atg16, Beclin 1, p62, m-TOR, AMPKα 1/2, and PINK1) were present in human spermatozoa. LC3 colocalized with p62 in the middle piece of the spermatozoa. Autophagy activation induced a significant increase in motility and a decrease in PINK1, TOM20 expression and caspase 3/7 activation. In contrast, autophagy inhibition resulted in decreased motility, viability, ATP and intracellular calcium concentration whereas PINK1, TOM20 expression, AMPK phosphorylation and caspase 3/7 activation were significantly increased. In conclusion our results show that autophagy related proteins and upstream regulators are present and functional in human spermatozoa. Modification of mitochondrial proteins expression after autophagy activation/inhibition may be indicating that a specialized form of autophagy named mitophagy may be regulating sperm function such as motility and viability and may be cooperating with apoptosis.
Subject(s)
Autophagy-Related Proteins/metabolism , Cell Movement , Spermatozoa/cytology , Spermatozoa/metabolism , AMP-Activated Protein Kinases/metabolism , Adenosine Triphosphate/metabolism , Adult , Autophagy/drug effects , Calcium/metabolism , Caspases/metabolism , Cell Movement/drug effects , Cell Survival/drug effects , Chloroquine/pharmacology , Enzyme Activation/drug effects , Humans , Hydrogen-Ion Concentration , Intracellular Space/metabolism , Macrolides/pharmacology , Male , Membrane Transport Proteins/metabolism , Mitochondrial Precursor Protein Import Complex Proteins , Phosphorylation/drug effects , Protein Kinases/metabolism , Receptors, Cell Surface/metabolism , Semen/metabolism , Sequestosome-1 Protein/metabolism , Sirolimus/pharmacology , Spermatozoa/drug effects , Spermatozoa/ultrastructureABSTRACT
The protective potential against Leishmania infection of the Leishmania chimerical Q protein administered as a single (Q) or double dose (Q+Q) without adjuvant was analyzed in a double-blind placebo controlled experiment in dogs. During vaccination the protein induced an intense early anti-Q response but no reactivity against total Leishmania infantum proteins was detected. Several end-points were taken into consideration. In the vaccinated animals the amount and intensity of clinical symptoms was lower than in the control group. Pathological signs of disease were observed in liver, kidney and spleen of all dogs from the control group in contrast to the normal appearance of the organs of the vaccinated animals. Vaccination was able to induce parasite clearance in most dogs. Only 1/7 dog was parasite DNA positive in skin in the Q group in contrast to 6/7 dogs in control and 4/7 in Q+Q. Significant anti-SLA clearance was observed in the vaccinated animals at the end of the study. Differences between control and vaccinated animals were also observed at the biochemical level, DTH and nitrite oxide production.
