Lee Beverley, Modha Geetanjalee, Watson Peter H, Dodd Janice, Troup Sandy, Blanchard Anne, Myal Yvonne
Department of Pathology, Faculty of Medicine, University of Manitoba, 770 Bannatyne Avenue, Man., R3E 0W3 Winnipeg, Canada.
Mol Cell Endocrinol. 2003 Jul 31;205(1-2):33-41. doi: 10.1016/s0303-7207(03)00210-7.
The function of the mouse submaxillary gland/prolactin inducible protein (mSMGP/mPIP), the homologue of the human gross cystic disease fluid protein 15 (GCDFP-15)/prolactin inducible protein (hPIP) remains unknown. The human gene, normally expressed in apocrine glands of healthy individuals, is aberrantly expressed in human breast cancers where it is regulated by hormones including androgens, and in prostate cancers. We have previously reported that in the adult mouse and rat, gene expression is tissue-specific for the salivary and lacrimal glands, and is hormonally regulated. In this study, we examine the endogenous pattern of mouse SMGP/PIP (mSMGP/mPIP) gene expression in mid- and late-embryonic, and in early postnatal development. Gene expression was analyzed by RT-PCR followed by Southern blot analysis, and by in situ hybridization. Gene expression was detected in the submandibular gland as early as embryonic day 14 (E14), a period that coincides with the initiation of submandibular gland development in the embryo, suggesting that mSMGP/mPIP may have a functional role in the developing gland. Nearing the end of gestation, E18, mSMGP/mPIP transcripts were localized in the proacinar cells of the gland, and gene expression continued to be maintained following birth. In addition, during early postnatal development, mSMGP/mPIP gene expression was detected in the other two major salivary glands, the sublingual and parotid, as well as in the lacrimal gland and in reproductive tissues. In the prostate, gene expression was turned off by 10 weeks of age. The spatial and temporal pattern of the mSMGP/mPIP gene expression, in addition to our recent demonstration that mSMGP/mPIP is found in mouse saliva and can bind bacteria, suggest that this protein may have a protective role in the mouse.
小鼠颌下腺/催乳素诱导蛋白（mSMGP/mPIP），即人类大汗腺囊性病液蛋白15（GCDFP - 15）/催乳素诱导蛋白（hPIP）的同源物，其功能尚不清楚。人类该基因通常在健康个体的顶泌汗腺中表达，在受雄激素等激素调控的人类乳腺癌以及前列腺癌中异常表达。我们之前报道过，在成年小鼠和大鼠中，该基因在唾液腺和泪腺中的表达具有组织特异性，且受激素调节。在本研究中，我们检测了小鼠SMGP/PIP（mSMGP/mPIP）基因在胚胎中后期以及出生后早期发育阶段的内源性表达模式。通过逆转录聚合酶链反应（RT-PCR），随后进行Southern印迹分析以及原位杂交来分析基因表达。早在胚胎第14天（E14）就在下颌下腺检测到基因表达，这一时期与胚胎下颌下腺发育的起始阶段相吻合，表明mSMGP/mPIP可能在发育中的腺体中发挥功能作用。接近妊娠末期，即E18时，mSMGP/mPIP转录本定位于腺体的前腺泡细胞中，并且出生后基因表达持续维持。此外，在出生后早期发育阶段，在另外两个主要唾液腺舌下腺和腮腺、泪腺以及生殖组织中也检测到了mSMGP/mPIP基因表达。在前列腺中，10周龄时基因表达关闭。mSMGP/mPIP基因表达的时空模式，以及我们最近证明mSMGP/mPIP存在于小鼠唾液中且能结合细菌，表明该蛋白可能在小鼠中具有保护作用。
