Regulated expression and ultrastructural localization of galectin-1, a proapoptotic β-galactoside-binding lectin, during spermatogenesis in rat testis
Regulated expression and ultrastructural localization of galectin-1, a proapoptotic β-galactoside-binding lectin, during spermatogenesis in rat testis
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DOI：
10.1095/biolreprod.102.006361
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发表时间：
2003-01-01
影响因子：
3.6
通讯作者：
Maldonado, CA
中科院分区：
文献类型：
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作者：
Dettin, L;Rubinstein, N;Maldonado, CA
半乳糖凝集素-1是一种高度保守的β-半乳糖苷结合蛋白，可诱导活化的T细胞凋亡并抑制自身免疫和慢性炎症的发展。为了深入了解半乳糖凝集素-1作为一种新的免疫赦免机制的潜在作用，我们研究了半乳糖凝集素-1在大鼠睾丸中的表达和超微结构定位。Galectin-1的表达进行了评估，通过Western印迹分析和免疫细胞化学定位在睾丸中获得的大鼠年龄从9至60天。这种碳水化合物结合蛋白的表达受到发育调控，其免疫标记在整个生精过程中表现出阶段特异性模式。使用抗半乳糖凝集素-1抗体的免疫金染色揭示了生精上皮中典型的支持细胞概况，主要在X-II期。在精子（阶段VI-VIII），强烈的标签观察到在生精上皮的腔极，定位于支持细胞的顶柄，成熟精子细胞的头部，和残留的细胞质的机构。此外，释放到管腔中的精子显示出强烈的免疫染色。继精子（第八阶段），半乳糖凝集素-1的表达恢复在支持细胞的基底部分，并逐步扩散到整个细胞的分化germinal细胞进行。免疫电子显微镜证实半乳糖凝集素-1分布在支持细胞的细胞核和细胞质突起和晚期精子细胞和残留体的头部和尾部。半乳糖凝集素-1的表面定位证明精子从附睾头。因此，半乳糖凝集素-1在精子发生周期中的表达调控表明这种免疫抑制凝集素在生殖生物学中的新作用。
Galectin-1, a highly conserved beta-galactoside-binding protein, induces apoptosis of activated T cells and suppresses the development of autoimmunity and chronic inflammation. To gain insight regarding the potential role of galectin-1 as a novel mechanism of immune privilege, we investigated expression and ultrastructural localization of galectin-1 in rat testis. Galectin-1 expression was assessed by Western blot analysis and immunocytochemical localization in testes obtained from rats aged from 9 to 60 days. Expression of this carbohydrate-binding protein was developmentally regulated, and its immunolabeling exhibited a stage-specific pattern throughout the spermatogenic process. Immunogold staining using the anti-galectin-1 antibody revealed the typical Sertoli cell profile in the seminiferous epithelium, mainly at stages X-II. During spermiation (stages VI-VIII), a strong labeling was observed at the luminal pole of seminiferous epithelium, localized on apical stalks of Sertoli cells, on heads of mature spermatids, and on bodies of residual cytoplasm. Moreover, spermatozoa released into the lumen showed a strong immunostaining. Following spermiation (stage VIII), galectin-1 expression was restored at the basal portion of Sertoli cells and progressively spread out through the whole cells as differentiation of germinal cells proceeded. Immunoelectron microscopy confirmed distribution of galectin-1 in nuclei and cytoplasmic projections of Sertoli cells and on heads and tails of late spermatids and residual bodies. Surface localization of galectin-1 was evidenced in spermatozoa from caput epididymis. Thus, the regulated expression of galectin-1 during the spermatogenic cycle suggests a novel role for this immunosuppressive lectin in reproductive biology.