Hydrogen peroxide produced by superoxide dismutase SOD-2 is required for sperm activation in Caenorhabditis elegans [Signal Transduction]

Superoxide dismutase (SOD) is a ubiquitous antioxidant enzyme that catalytically converts the superoxide radical to hydrogen peroxide (H2O2). In mammals, high SOD activity can be detected in sperm and seminal plasma, and a correlation between loss of SOD activity and male infertility has been observed; however, the underlying mechanisms remain to be clarified. Here, we report that the deletion of two major SOD genes in Caenorhabditis elegans, sod-1 and sod-2, cause sperm activation defects, thereby leading to a significant reduction in brood size. By analyzing the reactivity to the activation signals including Pronase and triethanolamine, we found that sod-1;sod-2 double mutant sperm have defects in pseudopod extension. Neither the content nor oxidative modification of major sperm protein, an essential cytoskeletal component for crawling movement, were significantly affected in sod-1;sod-2 mutant sperm. Surprisingly, H2O2, the dismutation product of SOD, could activate sod-1;sod-2 mutant sperm treated with Pronase. In contrast, the H2O2-scavenger ebselen completely inhibited pseudopod extension in wild-type sperm treated with Pronase. In addition, H2O2 could directly induce pseudopod extension in wild-type sperm. Pronase-triggered sperm activation analysis in sod-1 and sod-2 single mutants revealed that sod-2 is required for pseudopod extension. These results suggest that SOD-2 plays an important role in the sperm activation of C. elegans by producing H2O2 as an activator of pseudopod extension.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2tIzn5I
via IFTTT