Original article The mechanism and control of Jagged1 expression in Sertoli cells Ryu Okada, Taro Hara, Tomomi Sato, Nobuhiko Kojima, Yukio Nishina * Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan article info Article history: Received 30 November 2015 Received in revised form 8 February 2016 Accepted 15 February 2016 Keywords: Sertoli cell Jagged1 Seminiferous epithelial cycle TNF-a cAMP abstract The regulation of Sertoli cells by some hormones and signaling factors is important for normal sper- matogenesis. Notch signaling is considered to be necessary for normal spermatogenesis in mouse. In this study, we revealed two new facts about Sertoli cells by western blotting experiments on different types of primary cells and microdissected tubules. The first is that Sertoli cells express the Jagged1 ligand in mice testes. The second is that the expression level of Jagged1 oscillates in the seminiferous epithelial cycle. Therefore, we inferred that Jagged1 in Sertoli cells contributes to the Notch signaling involved in sper- matogenesis. Furthermore, we examined the regulation of Jagged1 expression and found that Jagged1 expression was suppressed by cAMP signaling and was promoted by TNF-a signaling in Sertoli cells. When cAMP and TNF-a were simultaneously added to Sertoli cells, Jagged1 expression was suppressed. Therefore, cAMP signaling dominates Jagged1 expression over TNF-a signaling. These results suggest that cAMP signaling may cause the periodicity of Jagged1 expression in the seminiferous epithelial cycle, and con- trolling Jagged1 expression by adding TNF-a or cAMP may contribute to normal spermatogenesis in vitro. © 2016, The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/). 1. Introduction Homeostatic and stable spermatogenesis is supported by the strict regulation of precise proliferation, differentiation, and meiosis of germ cells [1,2]. In 2011, Sato et al. found that in vitro organ culture with the gaseliquid interphase method can lead spermatogonia and germline stem cells to fertile sperm [3,4]. Furthermore, three-dimensional culture methods could recon- struct testicular cells to the structure of the seminiferous tubule, and collagen in matrigel promoted reconstruction of testes [5]. These in vitro culture methods might be a prospective application for regenerative therapy of infertility but could not lead germ cells to elongated spermatids in the reconstructed testis [5e7]. There- fore, an unknown factor is necessary for normal spermatogenesis in a reconstructed testis. Notch signaling, which is highly conserved from insect to vertebrate, relates to fate determination, lateral inhibition, and differentiation [8]. In Caenorhabditis elegans, Notch signaling promotes proliferation and inhibits differentiation of germline stem cells [9]. In the mammalian testis, localization of Notch signaling components was reported in several studies [10e14]. Notch1 has been shown to be expressed in undifferentiated spermatogonia and Sertoli cells. Notch2 and Notch3 are ubiqui- tously expressed in germ cells, and Jagged1 and Delta-like4 are expressed in elongated spermatids in adult testes [14]. However, other studies have reported Notch1 is expressed only in Sertoli cells [12], and Jagged1 is expressed in Sertoli cells [10,11]. Thus, the expression profiles of Notch signaling components in testes are controversial. On the other hand, loss- and gain-of-function analyses of Notch signaling in mouse testes have been reported [12,15,16]. Notch signaling in Sertoli cells inactivated by deletion of the protein O-fucosyltransferase1 showed normal spermatogen- esis [12], whereas RBPj knockout in Sertoli cells led to abnormal spermatogenesis and an atrophic tubule [15]. Blocking Notch signaling in all testicular cells by injection of g-secretase inhibitor into the tubule induced the collapse of the spermatogenic cycle and abnormal spermatozoa [17]. These studies suggest that Notch signaling in mouse testes is necessary for normal spermatogen- esis. Therefore, we inferred that elucidation of the role of Notch signaling for spermatogenesis would contribute to the recon- struction of testes and in vitro spermatogenesis. Abbreviations: RA, retinoic acid; FSH, follicle-stimulating hormone; cAMP, cyclic adenosine monophosphate; TNF-a, tumor necrosis factor-alpha; WT1, Wilm's tu- mor 1; P450scc, cytochrome P450 side-chain cleavage enzyme; Stra8, stimulated by retinoic acid gene 8. * Corresponding author. Tel.: þ81 45 787 2337. E-mail address: ynishina@yokohama-cu.ac.jp (Y. Nishina). Peer review under responsibility of the Japanese Society for Regenerative Medicine. Contents lists available at ScienceDirect Regenerative Therapy journal homepage: http://www.elsevier.com/locate/reth http://dx.doi.org/10.1016/j.reth.2016.02.005 2352-3204/© 2016, The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Regenerative Therapy 3 (2016) 75e81