Characterization of olfactomedin 4+ cells in prostate and urethral-tube epithelium during murine postnatal development and in adult mice.

Olfactomedin4 (Olfm4) is expressed in normal mouse prostate. However, Olfm4+ cells in the murine prostate have not been well characterized. In this study, we generated an Olfm4eGFP reporter mouse line with C57BL/6 mice and investigated the distribution of Olfm4/eGFP-expressing cells during postnatal development from P1, P7, P14, P20, P42, P56 to adult male mouse prostate and urethral tube. We observed Olfm4/eGFP expression in urogenital and prostatic epithelial cells during early postnatal development, which persisted into adulthood in urethral-tube and anterior-prostate (AP) epithelium. We found Olfm4+ cells are E-cadherin+/CD44+/Foxa1+ and some of subpopulation are Ck8+/Ck5+/Sca-1-/Ck4-/Syn- in the adult mouse AP epithelium. Functional studies of single-cell preparations of Olfm4/eGFP-expressing cells isolated from adult Olfm4eGFP mouse prostate demonstrated that Olfm4+ cells can grow and form colonies, spheres, or organoids in culture. Bioinformatic analysis of Olfm4+ cells using single-cell RNA sequencing meta data in adult mouse urethra (GSE145865) identified upregulation of genes related to cell and tissue migration and development, as well as upregulation of xenobiotic metabolism signaling pathways. In conclusion, Olfm4eGFP mouse is a novel model to further study Olfm4’s biological functions and Olfm4+ cells may contribute importantly to cellular processes supporting development and homeostasis of the epithelium in murine prostate and urethral tube.

嗅介蛋白4（Olfm4）在正常小鼠前列腺中表达。然而，小鼠前列腺中的Olfm4阳性细胞尚未得到很好的表征。在本研究中，我们利用C57BL/6小鼠培育出了一种Olfm4 - eGFP报告基因小鼠品系，并研究了从出生后第1天（P1）、第7天（P7）、第14天（P14）、第20天（P20）、第42天（P42）、第56天到成年雄性小鼠前列腺和尿道管发育过程中Olfm4/eGFP表达细胞的分布情况。我们观察到在出生后早期发育过程中泌尿生殖和前列腺上皮细胞中存在Olfm4/eGFP表达，这种表达在尿道管和前列腺前部（AP）上皮中持续到成年期。我们发现成年小鼠AP上皮中的Olfm4阳性细胞为E - 钙黏蛋白阳性/CD44阳性/Foxa1阳性，并且其中一些亚群为细胞角蛋白8阳性/细胞角蛋白5阳性/Sca - 1阴性/细胞角蛋白4阴性/突触素阴性。对从成年Olfm4 - eGFP小鼠前列腺中分离出的Olfm4/eGFP表达细胞的单细胞制剂进行的功能研究表明，Olfm4阳性细胞在培养过程中能够生长并形成集落、球体或类器官。利用成年小鼠尿道的单细胞RNA测序元数据（GSE145865）对Olfm4阳性细胞进行的生物信息学分析确定了与细胞和组织迁移及发育相关基因的上调，以及外源性物质代谢信号通路的上调。总之，Olfm4 - eGFP小鼠是进一步研究Olfm4生物学功能的一种新型模型，并且Olfm4阳性细胞可能对支持小鼠前列腺和尿道管上皮发育和内稳态的细胞过程有重要贡献。