Gene expression of luteinizing hormone receptor and steroidogenic enzymes during Leydig cell development
Gene expression of luteinizing hormone receptor and steroidogenic enzymes during Leydig cell development
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DOI：
10.1677/jme.0.0200119
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发表时间：
1998-02-01
影响因子：
3.5
通讯作者：
Zhai, J
中科院分区：
文献类型：
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作者：
Abney, TO;Zhai, J
注射乙烷二甲磺酸盐 (EDS) 可快速、选择性地破坏睾丸间质细胞 (LC)。 LC 再生发生在 EDS 处理的大鼠睾丸中，由前体 Leydig 细胞 (PLC) 分化而来。本研究旨在研究 PLC 再生过程中黄体生成素受体 (LHR) 和类固醇生成酶、胆固醇侧链裂解 (P-450(scc)) 和 17 α-羟化酶 (P-450(17 α)) mRNA 的变化模式。成熟（60 日龄）Sprague-Dawley 雄性大鼠接受单次腹腔注射 EDS，并在治疗后第 2 天至 60 天之间的不同时间处死。使用胶原酶消化-Percoll 梯度法从 EDS 处理的大鼠和年龄匹配的对照大鼠的睾丸中分离出富含 PLC 和 LC 的级分。从这些细胞群中提取总 RNA 并进行 Northern 印迹分析。从对照大鼠睾丸中分离的 LC 部分表达 LHR 的四种主要转录物，大小为 1.8、2.5、4.2 和 7.0 kb。来自对照的未分化的 PLC 部分仅表达截短的形式，即 18 kb 转录物。这种截短的 LHR 转录本也是 EDS 处理后第 2 天在 PLC 中检测到的唯一 LHR mRNA 种类。相比之下，在 EDS 治疗后第 10 天，在 PLC 部分中检测到了 LHR 的所有四个转录本。此后，PLC 级分中全长 7.0 kb 转录物的水平增加，并在 EDS 处理后第 24 天至 36 天之间达到峰值。伴随着 7.0 kb 转录本的增加，截短的 1.8 kb 转录本的数量减少，并在治疗后第 16 天和第 36 天之间达到最低点。在该细胞部分中观察到的变化反映了 PLC 分化为 LC 的过程。在 EDS 处理后第 45 天，PLC 部分中 7.0 kb 转录物的水平下降，而 1.8 kb 形式增加，反映了该细胞部分的 LC 再生已完成。到 EDS 处理后第 60 天，1.8 kb 转录物的水平升至未分化对照 PLC 中观察到的值，并且在 PLC 级分中不再检测到其他转录本，表明 PLC 级分中的细胞再次处于未分化阶段。类固醇生成酶 P-450(scc) 和 P-450(17 α) 的信使 RNA 在对照 LC 级分中表达。在对照大鼠的 PLC 部分中均未检测到这两种 mRNA。 EDS 处理后第 10 天，P-450(scc) 和 P-450(17 α) mRNA 首先在 PLC 级分中表达。此后，PLC部分中P-450(scc)和P-450(17α) mRNA的水平增加，并分别在EDS治疗后第24天和第36天以及第24天和第45天达到峰值。 EDS 处理后第 60 天，PLC 级分中不再表达 P-450(scc) 和 P-450(17 α) mRNA。这些模式也反映了PLC分化为功能性LC的过程。这些结果首次证明对照睾丸中的PLC是未分化的，并且不表达功能性LHR和类固醇生成酶或其mRNA。然而，PLC 的特点是表达截短的 1.8 kb LHR mRNA 转录物。功能性 LHR 和类固醇生成酶仅在 EDS 处理后分化为 LC 期间在 PLC 中表达。 LC 再生后，PLC 返回到未分化阶段。
Testicular Leydig cells (LC) are rapidly and selectively destroyed by an injection of ethane dimethane sulfonate (EDS). LC regeneration occurs in the testis of the EDS-treated rats from the differentiation of the precursor Leydig cells (PLC). This study was designed to investigate the patterns of change in the mRNAs for the luteinizing hormone receptor (LHR) and the steroidogenic enzymes, cholesterol side chain cleavage (P-450(scc)) and 17 alpha-hydroxylase (P-450(17 alpha)) during LC regeneration from PLCs. Mature (60 days of age) Sprague-Dawley male rats received a single intraperitoneal injection of EDS and were killed at different times between days 2 and 60 post-treatment. PLC- and LC-enriched fractions were isolated from the testes of the EDS-treated rats and age-matched control rats using a collagenase digestion-Percoll gradient method. Total RNA was extracted from these cell populations and subjected to Northern blot analysis.The LC fraction isolated from testes of control rats expressed four major transcripts of the LHR, sized 1.8, 2.5, 4.2 and 7.0 kb. The undifferentiated PLC fraction from controls expressed only a truncated form, the 18 kb transcript. This truncated LHR transcript was also the only LHR mRNA species detected in PLCs at day 2 post-EDS treatment. In contrast, all four transcripts of the LHR were detected in the PLC fraction at day 10 post-EDS treatment. The levels of the full length 7.0 kb transcript increased thereafter and reached a peak between days 24 and 36 post-EDS treatment in the PLC fraction. Concomitant with the increase in the 7.0 kb transcript, the truncated 1.8 kb transcript decreased in amount and reached a nadir between days 16 and 36 post-treatment. The changes observed in this cell fraction reflect the process of differentiation of PLCs into LCs. At day 45 post-EDS treatment, the level of the 7.0 kb transcript decreased while the 1.8 kb form increased in the PLC fraction, reflecting the completion of LC regeneration from this cell fraction. By day 60 post-EDS treatment, the levels of the 1.8 kb transcript rose to the value observed in undifferentiated control PLCs and the other transcripts were no longer detected in the PLC fraction, indicating that cells in the PLC fraction were again in an undifferentiated stage.Messenger RNAs for both the steroidogenic enzymes, P-450(scc) and P-450(17 alpha) were expressed in the control LC fraction. Neither of these two mRNAs were detected in the PLC fraction of the control rats. P-450(scc) and P-450(17 alpha) mRNAs were first expressed in the PLC fraction at day 10 post-EDS treatment. Thereafter, the levels of P-450(scc) and P-450(17 alpha) mRNAs increased in the PLC fraction and reached a peak between days 24 and 36 and days 24 and 45 post-EDS treatment respectively. P-450(scc) and P-450(17 alpha) mRNAs were no longer expressed in the PLC fraction at day 60 post-EDS treatment. These patterns also reflect the process of differentiation of PLCs into functional LCs.These results demonstrate for the first time that PLCs in the control testis are undifferentiated and do not express functional LHR and steroidogenic enzymes or their mRNAs. The PLCs are characterized, however, by the expression of a truncated 1.8 kb transcript of the LHR mRNA. Functional LHR and steroidogenic enzymes are expressed in PLCs only during their differentiation into LCs after EDS treatment. Subsequent to LC regeneration, the PLCs return to an undifferentiated stage.