Porcine growth hormone (pGH) has many important biological functions and roles, and the biological activity of pGH is closely related with its cell behavior and characteristics. However, so far, the behavior of pGH in swine testicular cell remains unclear. For this, in the current work, the swine testicular cell line (ST) was used as an in vitro model, and CLSM (Confocal laser scanning microscope), IFA (Indirect immunofluorescence assay), FCM (Flow cytometry) and WB (Western-blotting) were used to explore the pGH’s cell behivior and function, and the results showed that pGH and GHR could internalize into ST cell and transported to the nucleus. Furthermore, we studied the internalization kinetics of pGH and GHR on ST cell, and found that pGH and GHR internalizes into ST cell in a time-dependent manner. More importantly, we also investigated the potential molecular functions of pGH-GHR after it entered into the cell nuclei. The results indicated that nuclear-localized GHR could participate in cell proliferation by regulating the signal intensity of STAT5. In summary, our current research shows that the nuclear-localized pGH-GHR participates in the cell proliferation of ST cell, which lays a solid foundation for further research on the regulatory effect of pGH on testicular tissue.

猪生长激素(pGH)具有许多重要的生物学功能和作用，pGH的生物学活性与其细胞行为和特性密切相关。然而，到目前为止，猪睾丸细胞中pGH的行为仍不清楚。为此，在目前的工作中，猪睾丸细胞系（ST）被用作体外模型，CLSM（共聚焦激光扫描显微镜）、IFA（间接免疫荧光测定）、FCM（流式细胞术）和WB（Western-印迹法）用于探索pGH的细胞行为和功能，结果表明pGH和GHR可以内化到ST细胞并转运至细胞核。此外，我们研究了pGH和GHR在ST细胞上的内化动力学，发现pGH和GHR以时间依赖性方式内化到ST细胞中。更重要的是，我们还研究了 pGH-GHR 在进入细胞核后的潜在分子功能。结果表明，核定位的GHR可以通过调节STAT5的信号强度参与细胞增殖。综上所述，我们目前的研究表明，核定位的pGH-GHR参与了ST细胞的细胞增殖，为进一步研究pGH对睾丸组织的调节作用奠定了坚实的基础。