Author
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Submitted to: Journal of Histochemistry and Cytochemistry
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/22/2008 Publication Date: 6/12/2008 Citation: Kirschke, C.P., Huang, L. 2008. Expression of ZNT (SLC30) family members in the epithelium of the mouse prostate during sexual maturation. Journal of Histochemistry and Cytochemistry (2008) 39:359-370. Interpretive Summary: Growth and maturation of the prostate, a secretory gland containing four distinctive lobes (anterior, dorsal, lateral, and ventral), in the male genital tract is dependent on androgen (testosterone), a male hormone secreted by testes. The prostate produces a bulk of zinc-enriched fluid that is essential for fertility. A prostate contains ~10-fold higher cellular zinc than any other soft organs, such as liver, brain, and kidney in the body. To establish protein expression profiles of zinc transporters involved in zinc export and intracellular zinc sequestration/storage in the mouse prostates during sexual maturation, ZNT1, 2, and 4-7 was investigated by immunohistochemistry, a method to localize proteins in cells of a biological tissue section using antibodies specific for the proteins of interests. Our study demonstrated that ZNT proteins were differentially expressed in the epithelium (fluid producing cells) of the prostate in the period of 4-8 weeks of age. Overlapping expression and localization of ZNT proteins were also observed. ZNT1 was mainly localized on the lateral membrane of the epithelium of the prostate. The amount of ZNT1 expression was greatly reduced when the prostate was matured at 8 weeks. All other ZNT proteins were predominantly intracellularly (inside cells) resided in the epithelium of the prostate. Among differences were a staining of ZNT2 along the lateral and apical membrane, a luminal border staining of ZNT4, a strong expression of ZNT5 resembling the staining of the Golgi complex (a cell structure to process and package the macromolecules such as proteins and lipids that are synthesized by the cell) in the ventral lobe, a relatively uniform expression in the amount of ZNT6 across the lobes and ages, and a high expression of ZNT7 in all lobes at 6 weeks. In conclusion, the expression patterns and levels of ZNT proteins revealed in this study are consistent with their roles in cellular zinc accumulation in different compartments of the epithelium of the prostate. Technical Abstract: The mouse prostate is an androgen-dependent secretory gland containing four distinctive lobes (anterior, dorsal, lateral, and ventral) in the male genital tract. They produce a bulk of zinc-enriched seminal secretion that is essential for fertility. A prostate contains ~10-fold higher cellular zinc than any other soft organs in the body. To establish protein expression profiles of zinc transporters involved in zinc export and intracellular zinc sequestration/storage in the mouse prostates during sexual maturation, ZNT1, 2, and 4-7 was investigated by immunohistochemistry. Our study demonstrated that ZNT proteins were differentially expressed in the epithelium of the prostate in the period of 4-8 weeks of age. Overlapping expression and localization of ZNT proteins were also observed. ZNT1 was mainly localized on the lateral membrane of the epithelium of the prostate. The amount of ZNT1 expression was greatly reduced when the prostate was matured at 8 weeks. All other ZNT proteins were predominantly intracellularly resided in the epithelium of the prostate. Among differences were a staining of ZNT2 along the lateral and apical membrane, a luminal border staining of ZNT4, a strong expression of ZNT5 resembling the staining of the Golgi complex in the ventral lobe, a relatively uniform expression in the amount of ZNT6 across the lobes and ages, and a high expression of ZNT7 in all lobes at 6 weeks. In conclusion, the expression patterns and levels of ZNT proteins revealed in this study are consistent with their roles in cellular zinc accumulation in different compartments of the epithelium of the prostate. |
