The expression and distribution of neural salient serine/arginine-rich protein 1 in rat retina

Dephosphorylated NSSR1 is induced by androgen in mouse epididymis and phosphorylated NSSR1 is increased during sperm maturation

NSSR1 (Neural salient serine/arginine rich protein 1, alternatively SRp38) is a newly identified RNA splicing factor and predominantly expressed in neural tissues. Here, by Western blot analysis and immunofluorescent staining, we showed that the expression of dephosphorylated NSSR1 increased significantly during development of the caput epididymis. In adult mice, phosphorylated NSSR1 was mainly expressed in the apical side of epithelial cells, and dephosphorylated NSSR1 in caput epididymis was upregulated in a testosterone dependent manner. In addition, subcellular immunoreactive distribution of NSSR1 varied in different regions of the epididymis. With respect to the sperm, phosphorylated NSSR1 was detected in the mid-piece of the tail as well as the acrosome. Furthermore, NSSR1 was released from the sperm head during the capacitation and acrosome reaction. These findings for the first time provide the evidence for the potential roles of NSSR1 in sperm maturation and fertilization.

NSSR1 is regulated by testosterone in the mouse uterus and extensively expressed in endometrial carcinoma

Neural salient serine/arginine-rich protein 1 (NSSR1) has been found to play important roles in inhibiting alternative splicing during heat shock and mitosis and is predominantly expressed in neural tissues such as cerebral neurons, cerebellar Purkinje cells and bipolar cells of the retina. Recently, NSSR1 has also been shown to be highly expressed in the testes, suggesting its potential roles in reproductive system. In this report, the expression of NSSR1 in the columnar epithelium of the endometrium and gland epithelium during the development of the mouse uterus, the regulation of NSSR1 level by testosterone in the adult mouse uterus, and expression level of NSSR1 in both human endometrial carcinomas and ovarian cancers were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemistry. We demonstrated that the expression of NSSR1 was developmentally regulated in the columnar epithelium of the endometrium and gland epithelium in the mouse uterus. Additionally, the NSSR1 level in the mouse uterus was maintained and regulated by testosterone. Interestingly, an enhanced level of NSSR1 was observed in both human endometrial carcinomas and ovarian cancers. Our results suggest that expression and distribution of NSSR1 is developmentally and hormonally regulated and up-regulated in endometrial carcinomas as well as ovarian cancers, indicating its potential involvement in uterine development and tumorgenesis.

The expression pattern of heterogeneous nuclear ribonucleoprotein R in rat retina

The heterogeneous nuclear ribonucleoproteins (hnRNPs) play important roles in DNA repairing, cell signaling, telomere biogenesis, and in regulating gene expression at both transcriptional and translational levels. In the present study, we demonstrated that the expression of hnRNP-R1 and hnRNP-R2 is developmentally regulated in rat retina. The neural specific isoform hnRNP-R2 is expressed in 7-day postnatal rat retina, but not in the adult retina. The positive immunohistochemistry signal of hnRNP-R1 is extensively distributed in the outer plexiform layer, inner nuclear layer and ganglion cell layer of rat retina. Double staining experiments showed that the positive signal of hnRNP-R1 is distributed in ON-type bipolar cells and localized in the cytoplasm, dendrites and axon terminals. In addition, the hnRNP-R1 distribution is regulated in rat retina during circadian. The present investigation suggests that hnRNP-R may play roles in retinal development and light-elicited cellular activities.