Assessment of Atg7 and LC3II/LC3, as The Markers of Autophagy,
in Sperm of Infertile Men with Globozoospermia:
A Case-Control Study
Assessment of relationship between LC3II/LC3 and Autophagy-related 7 (Atg7) proteins, as markers of autophagy, as well as evaluating the sperm parameters and DNA fragmentation in spermatozoa of infertile men with globozoospermia.
Materials and Methods
In this case-control study, 10 semen samples from infertile men with globozoospermia and 10 fertile individuals were collected, and the sperm parameters, sperm DNA fragmentation, and main autophagy markers (Atg7 and LC3II/LC3) were assessed according to World Health Organization (WHO) criteria, TUNEL assay, and western blot technique, respectively.
The mean of sperm concentration and motility were significantly lower, while the percentage of abnormal spermatozoa and DNA fragmentation were significantly higher in infertile men with globozoospermia compared to fertile individuals (P<0.01). Unlike the relative expression of LC3II/LC3 that did not significantly differ between the two groups, the relative expression of ATG7 was significantly higher in infertile men with globozoospermia compared to fertile individuals (P<0.05). There was a significantly negative correlation between the sperm concentration (r=-0.679; P=0.005) and motility (r=-0.64; P=0.01) with the expression of ATG7, while a significantly positive association was founf between the percentage of DNA fragmentation and expression of ATG7 (0.841; P =0.018).
The increased expression of ATG7 and unaltered expression of LC3II/LC3 may indicate that the autophagy pathway is initiated but not completely executed in spermatozoa of individuals with globozoospermia. A significant correlation of ATG7 expression with increased sperm DNA fragmentation, reduced sperm concentration, and sperm motility may associate with the activation of a compensatory mechanism for promoting deficient spermatozoa to undergo cell death by the autophagy pathway. Therfore, this pathway could act as a double-edged sword that, at the physiological level, is involved in acrosome biogenesis, while, at the pathological level, such as globozoospermia, could act as a compensatory mechanism.