(Open access funding provided by Semmelweis University)
Members of the NOX/DUOX family of NADPH oxidases are responsible for regulated ROS
production in diverse cells and tissues. Detection of NOX/DUOX proteins at the protein
level remains an important challenge in the field. Here we report the development
and characterization of a novel anti-NOX5 monoclonal antibody, which recognizes the
human NOX5 protein in both Western blot, immunocytochemistry, and histochemistry applications.
With the help of the antibody we could successfully detect both heterologously and
endogenously expressed NOX5 in mammalian cells. Furthermore, we could also detect
NOX5 protein in the human spleen, testis, and ovary. Immunohistochemical studies on
human testis revealed that NOX5 localized to spermatogenic cells. This expression
pattern was also supported by the result of in silico analysis of single-cell RNA
sequencing data that indicated that NOX5 protein is present in developing spermatids
and spermatocytes. Mature spermatozoa, however, did not contain detectable NOX5. In
the human ovary, both immunostaining and single-cell RNA sequencing suggest that NOX5
is expressed in interstitial fibroblasts and theca cells. We also analyzed vascular
cells for the presence of NOX5 and we found that NOX5 expression is a fairly specific
feature of splenic endothelial cells.
