Hsd17b7 undergoes dynamic subcellular localization during Neuro2a differentiation

Enzymes within the cholesterol biosynthesis pathway, particularly those in post-squalene biosynthesis, have been linked to abnormal neurodevelopment. Alterations of individual enzymes manifest unique brain phenotypes, suggesting each enzyme has distinct roles within the mammalian neural cell. However, a comprehensive characterization of cholesterol biosynthesis enzymes to understand these differences has yet to be fully obtained. Therefore, this study aimed to contribute to this growing body of knowledge by characterizing the subcellular localization of the cholesterol biosynthesis enzyme Hydroxysteroid-17-beta7 (Hsd17b7) within a mammalian neural cell line. Using mouse Neuro2a cells, we compared expression patterns between both endogenous Hsd17b7 and GFP-tagged constructs. Using confocal microscopy, we noted Hsd17b7 absence in the Golgi and lysosomes while confirming its presence in the endoplasmic reticulum. Of interest, we also observed co-localization with the nuclear membrane, which had not been established. Upon 24-hour serum deprivation, patterns of Hsd17b7-GFP in differentiated cells were still observed in the cell body, as seen in the undifferentiated cells. However, we also observed evidence of GFP-positive protein localization within MAP2-positive neurites. Co-staining with Hsd17b7 antibody and conjugated Phalloidin further supported the localization of Hsd17b7 within developing neurites. Together, this suggests a potential role for Hsd17b7 within early axons and dendrites, however, further investigation is needed to determine potential implications on neural differentiation.