Campolina-Silva Gabriel H, Hess Rex A, Oliveira Cleida A
Department of Morphology, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, CEP 31270-901 Belo Horizonte, MG, Brazil.
Department of Comparative Biosciences, University of Illinois, 2001, S. Lincoln, Urbana, IL 61802-6199, USA.
Gen Comp Endocrinol. 2019 Mar 1;273:3-10. doi: 10.1016/j.ygcen.2018.02.003. Epub 2018 Feb 7.
The balance between cell proliferation and apoptosis is important for maintenance of male fertility, being influenced by a variety of stimuli including androgens and estrogens. However, studies concerning regulation of these processes along the male reproductive tract under physiological conditions are scarce. Therefore, in this study, we investigated the profile of cell proliferation and apoptosis in the efferent ductules and epididymis of the Neotropical bat Artibeus lituratus, a seasonal breeder that presents natural variation in components of the androgen and estrogen responsive systems along the circannual cycle. Low rates of cell proliferation and apoptosis were found in the efferent ductules and epididymis of A. lituratus during the reproductive period, as few epithelial cells were positive for MCM7 (proliferation marker) and cleaved caspase-3 or TUNEL (apoptosis markers). In contrast, during the regressive period, the rate of both proliferating and apoptotic cells was significantly higher in the epithelium lining the efferent ductules as well as throughout the epididymis. The increased proliferative activity at this phase was positively correlated with the expression of estrogen receptor alpha (ERα), whereas the variation in apoptosis appears to be unrelated to the local expression of androgen and estrogen receptors. Together, these data suggest that cell proliferation and apoptosis are differentially modulated in the efferent ductules and epididymis of A. lituratus during the annual reproductive cycle, and support the hypothesis that ERα may be important in preparing the male reproductive tract for sexual recrudescence.
细胞增殖与凋亡之间的平衡对于维持雄性生育能力至关重要，这一平衡受到包括雄激素和雌激素在内的多种刺激的影响。然而，关于生理条件下雄性生殖道这些过程调控的研究却很匮乏。因此，在本研究中，我们调查了新热带区蝙蝠南美果蝠（Artibeus lituratus）输出小管和附睾中的细胞增殖与凋亡情况，南美果蝠是季节性繁殖动物，其雄激素和雌激素反应系统的成分在全年周期中呈现自然变化。在繁殖期，南美果蝠的输出小管和附睾中细胞增殖和凋亡率较低，因为很少有上皮细胞对MCM7（增殖标记物）、裂解的半胱天冬酶-3或TUNEL（凋亡标记物）呈阳性。相比之下，在消退期，输出小管内衬上皮以及整个附睾中的增殖细胞和凋亡细胞率均显著更高。此阶段增殖活性的增加与雌激素受体α（ERα）的表达呈正相关，而凋亡的变化似乎与雄激素和雌激素受体的局部表达无关。总之，这些数据表明，在全年繁殖周期中，南美果蝠的输出小管和附睾中细胞增殖和凋亡受到不同调节，并支持ERα可能在为雄性生殖道性复壮做准备中起重要作用这一假说。
