Sperm dynein ATPase and ATPases associated with various cellular activities (AAA+): regulation in oligo-astheno-teratozoospermia and necrozoospermia as extreme sperm motility disorders

Asthenozoospermia is the most frequent sperm motility disorder, but there are other more extreme sperm motility disorders, namely oligo-astheno-teratozoospermia (OAT) and necrozoospermia. There are several cellular mechanisms known for OAT and necrozoospermia, but there are limited data on dynein ATPase and ATPases associated with various cellular activities (AAA+). AAA1 is involved in ATP hydrolysis, while AAA2 is entangled in ATP-binding pocket. This study was conducted to investigate the role of dynein ATPase activity and quantification of AAA dynein. Spermatozoa from 14 men with OAT, 11 men with necrozoospermic and 17 men with normoozspermic samples were used in this study. Makler chamber was used to determine sperm concentration and motility, while Papanicolaou stained semen smears using World Health Organization-fifth edition criteria was performed to determine sperm morphology, and dynein ATPase was quantified by calculation of released inorganic phosphate. AAA was quantified by enzyme-linked immunosorbent assay, whereas the distribution was determined by immunocytochemistry. This study showed that the dynein ATPase activity in OAT and necrozoospermia was lower than in the normozoospermic group (2.68±0.76, 1.01±0.31, 7.22±1.08 µmol Pi/mg protein/h, respectively, P<0.05), as well as the amounts of AAA1 and AAA2. In addition, staining for AAA in the sperm tail paralleled the dynein ATPase activity and quantity of AAA, being the highest in sperm from normozoospermic samples, lower in sperm from OAT samples, and almost undetectable in sperm from necrozoospermic samples. The structure and function of damaged sperm dynein may alter dynein ATPase activity and levels of AAA1 and AAA2.