Castration- and Aging-Induced Changes in the Expression of Zinc Transporter and Metallothionein in Rat Prostate
Castration- and Aging-Induced Changes in the Expression of Zinc Transporter and Metallothionein in Rat Prostate
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DOI：
10.2164/jandrol.110.011205
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发表时间：
2011-03-01
影响因子：
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通讯作者：
Hirano, Kazuyuki
中科院分区：
文献类型：
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作者：
Iguchi, Kazuhiro;Morihara, Naoaki;Hirano, Kazuyuki
前列腺组织含有高浓度的锌。前列腺中的锌含量在前列腺疾病中发生变化，如良性前列腺增生和前列腺癌，这些疾病随着年龄的增长而发生得更频繁。在动物模型中，去势后前列腺锌含量也会降低。目前尚不清楚前列腺锌含量是如何调节的，因此，为了阐明锌稳态的机制，我们研究了老年或去势大鼠前列腺中的锌含量以及锌转运蛋白和金属硫蛋白的表达。用火焰原子吸收光谱法测定锌含量。采用实时荧光定量逆转录聚合酶链反应技术检测锌转运蛋白和金属硫蛋白的mRNA表达。老年大鼠（21月龄）腹侧前列腺（VP）锌转运蛋白Slc 30 a2（Znt 2）的表达量约为青年大鼠（4月龄）VP的21倍，青年大鼠VP中锌含量显著高于老年大鼠。青年和老年大鼠前列腺外侧（LP）和背侧的锌含量没有差异。在去势大鼠的LP中观察到金属硫蛋白-3（Mt3）表达减少，睾酮替代可防止这种减少。锌含量和Mt3表达水平在大鼠LP中显著相关。我们的研究结果表明，Mt3可以发挥关键作用，锌稳态在大鼠LP。
Prostate tissue contains high concentrations of zinc. Zinc content in the prostate gland changes in prostatic disease, such as benign prostate hyperplasia and prostate cancer, which occur more frequently with increasing age. Prostate zinc content is also known to decrease after castration in animal models. It is not clear how prostate zinc content is regulated; therefore, to clarify the mechanisms underlying zinc homeostasis, we examined zinc content and the expression of zinc transporters and metallothioneins in the prostates of aged or castrated rats. Zinc concentration was measured by flame atomic absorption spectrometry. The mRNA expression of zinc transporters and metallothioneins was determined by real-time reverse transcriptase polymerase chain reaction analysis. The expression of the zinc transporter Slc30a2 (Znt2) in ventral prostate (VP) of aged rats (21 months) was approximately 21-fold higher than that in VP of young rats (4 months), and zinc levels in VP of young rats increased significantly compared with that in aged rats. Zinc content in lateral prostate (LP) and dorsal prostate did not differ between young and aged rats. Decreased metallothionein-3 (Mt3) expression was observed in LP of castrated rats, and this reduction was prevented by testosterone replacement. Zinc content and Mt3 expression levels correlated significantly in rat LP. Our findings suggest that Mt3 could play a critical role in zinc homeostasis in rat LP.