Leydig cells from neonatal pig testis abundantly express 11β-hydroxysteroid dehydrogenase (11β-HSD) type 2 and effectively inactivate cortisol to cortisone
Leydig cells from neonatal pig testis abundantly express 11β-hydroxysteroid dehydrogenase (11β-HSD) type 2 and effectively inactivate cortisol to cortisone
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DOI：
10.1016/j.jsbmb.2007.07.003
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发表时间：
2008-01-01
影响因子：
4.1
通讯作者：
Nakajin, S.
中科院分区：
文献类型：
--
作者：
Honda, Y.;Ohno, S.;Nakajin, S.
11 β-羟基类固醇脱氢酶（11 β-HSD）同工酶，命名为1型和2型，催化生理活性糖皮质激素和无活性11-酮形式的相互转化。通过逆转录聚合酶链反应、蛋白质印迹和免疫组织化学染色，在新生猪睾丸和从睾丸纯化的Leydig细胞中确定了1型和2型的存在。2型mRNA在新生猪睾丸中有高水平表达。特别是，在整个睾丸中，与1型相比，2型的表达水平更高。此外，将睾丸中的这些表达水平与已知具有高水平的猪肝和肾中相应同工酶的表达水平进行比较。接下来，在完整的Leydig细胞糖皮质激素代谢的方向进行了检查，只有从皮质醇到可的松的氧化检测。实际上没有检测到可的松还原为皮质醇。使用微粒体酶制剂从Leydig细胞，2型表现出强大的氧化活性，活性高于氧化活性催化的1型同工酶。在动力学分析中，1型的Km和V-max分别为1.36 μ M和0.91 nmol/（h mg），2型分别为0.38 μ M和1.25 nmol/（h mg）。本研究使用新生猪睾丸的结果表明，不仅11 β-HSD 1型，而且大量表达的2型，在猪Leydig细胞中的皮质醇失活中起重要作用，此外，过量的皮质醇将导致糖皮质激素介导的甚至新生猪Leydig细胞中睾酮产生的抑制。(c)2007爱思唯尔有限公司保留所有权利。
11 beta-Hydroxysteroid dehydrogenase (11 beta-HSD) isozymes, designated types 1 and 2, catalyze the interconversion of physiologically active glucocorticoids and inactive 11-keto forms. The presence of types 1 and 2 was determined in neonatal pig testis and Leydig cells purified from testes by reverse transcription polymerase chain reaction, Western blotting, and immunohistochemical staining. Type 2 mRNA was expressed at a high level in neonatal pig testis. In particular, in the entire testis, a higher level of type 2 was expressed compared to type 1. Furthermore, these expression levels in the testis were compared with the expression levels of the respective isozymes in pig liver and kidney, which are known to have high levels. Next, the direction of glucocorticoid metabolism in intact Leydig cells was examined, and only oxidation from cortisol to cortisone was detected. Virtually no reduction of cortisone to cortisol was detected. Using a microsomal enzyme preparation from Leydig cells, type 2 exhibited potent oxidation activity, and the activity was higher than the oxidation activity catalyzed by the type 1 isozyme. In kinetic analysis, the K-m and V-max for type 1 were 1.36 mu M and 0.91 nmol/(h mg), respectively, and 0.38 mu M and 1.25 nmol/(h mg), respectively, for type 2. The results of the present study using neonatal pig testis suggest that not only 11 beta-HSD type 1 but also type 2, which is abundantly expressed, plays important roles in cortisol inactivation in pig Leydig cells, and furthermore, that excess cortisol will cause glucocorticoid-mediated suppression of testosterone production in even neonatal pig Leydig cells. (c) 2007 Elsevier Ltd. All rights reserved.