Gene Expression Patterns最新文献

Development of the mammalian telencephalon, which is the most complex region of the central nervous system, is precisely orchestrated by many signaling molecules. Wnt signaling derived from the cortical hem, a signaling center, is crucial for telencephalic development including cortical patterning and the induction of hippocampal development. Secreted protein R-spondin (Rspo) 1–4 and their receptors, leucine-rich repeat-containing G-protein-coupled receptor (Lgr) 4–6, act as activators of Wnt signaling. Although Rspo expression in the hem during the early stages of cortical development has been reported, comparative expression analysis of Rspos and Lgr4–6 has not been performed. In this study, we examined the detailed spatiotemporal expression patterns of Rspo1–4 and Lgr4–6 in the embryonic and postnatal telencephalon to elucidate their functions. In the embryonic day (E) 10.5–14.5 telencephalon, Rspo1–3 were prominently expressed in the cortical hem. Among their receptors, Lgr4 was observed in the ventral telencephalon, and Lgr6 was highly expressed throughout the telencephalon at the same stages. This suggests that Rspo1–3 and Lgr4 initially regulate telencephalic development in restricted regions, whereas Lgr6 functions broadly. From the late embryonic stage, the expression areas of Rspo1–3 and Lgr4–6 dramatically expanded; their expression was found in the neocortex and limbic system, such as the hippocampus, amygdala, and striatum. Increased Rspo and Lgr expression from the late embryonic stages suggests broad roles of Rspo signaling in telencephalic development. Furthermore, the Lgr⁺ regions were located far from the Rspo⁺ regions, especially in the E10.5–14.5 ventral telencephalon, suggesting that Lgrs act via a Rspo-independent pathway.

Adult zebrafish regenerate their appendages (fins) after amputation including the regeneration of bone structures (fin rays). Fibroblast growth factor (Fgf) signaling, which is involved in morphogenetic processes during development, has been shown to be essential for the process of fin regeneration. Moreover, mutations in Fgf pathway component genes lead to abnormal skeletal growth in teleosts and mammals, including humans, illustrating the importance of Fgf signaling in the growth control of tissues. Here, we revisited Fgf signaling pathway component expression by RNA in situ hybridization to test for the expression of about half of the ligands and all receptors of the pathway in the regenerating zebrafish fin. Expression patterns of fgf7, fgf10b, fgf12b, fgf17b and fgfr1b have not been reported in the literature before. We summarize and discuss known and novel localization of expression and find that all five Fgf receptors (fgfr1a, fgfr1b, fgfr2, fgfr3 and fgfr4) and most of the tested ligands are expressed in specific regions of the regenerate. Our work provides a basis to study domain specific functions of Fgf signaling in the regenerating teleost appendage.

Objective

Angiogenesis is a key process of repairing tissue damage, and it is regulated by the delicate balance between anti-angiogenesis factors. In the present study, we investigate whether transcription factor cellular promoter 2 (TFCP2) is required for upstream binding protein 1 (UBP1)-mediated angiogenesis.

Methods

Levels of UBP1 and TFCP2 in human umbilical vein endothelial cells (HUVECs) are detected by quantitative polymerase chain reaction (q-PCR) and Western blotting (WB). Effects of UBP1 on angiogenesis and migration are detected by tube-like network formation on matrigel assay and scratch assay. The interaction between UBP1 and TFCP2 is predicted and verified by STRING and Co-immunoprecipitation (Co-IP).

Results

Firstly, the UBP1 expression level was up-regulated in the stimuli of vascular endothelial growth factor (VEGF) in HUVECs, and the knockdown of UBP1 inhibited angiogenesis and migration of HUVECs. Then, UBP1 interacted with TFCP2. Besides, the TFCP2 expression level was up-regulated in VEGF-stimulated HUVECs. Furthermore, knockdown of TFCP2 inhibited angiogenesis and migration in VEGF-stimulated HUVECs, and down-regulation of UBP1 enhanced the inhibition.

Conclusion

TFCP2 also plays a key role in UBP1 mediated angiogenesis of HUVECs stimulated by VEGF. These findings will provide a new theoretical basis for the treatment of angiogenic diseases.

Heterogeneous nuclear ribonucleoprotein L (hnRNPL) is a conserved RNA binding protein (RBP) that plays an important role in the alternative splicing of gene transcripts, and thus in the generation of specific protein isoforms. Global deficiency in hnRNPL in mice results in preimplantation embryonic lethality at embryonic day (E) 3.5. To begin to understand the contribution of hnRNPL-regulated pathways in the normal development of the embryo and placenta, we determined hnRNPL expression profile and subcellular localization throughout development. Proteome and Western blot analyses were employed to determine hnRNPL abundance between E3.5 and E17.5. Histological analyses supported that the embryo and implantation site display distinct hnRNPL localization patterns. In the fully developed mouse placenta, nuclear hnRNPL was observed broadly in trophoblasts, whereas within the implantation site a discrete subset of cells showed hnRNPL outside the nucleus. In the first-trimester human placenta, hnRNPL was detected in the undifferentiated cytotrophoblasts, suggesting a role for this factor in trophoblast progenitors. Parallel in vitro studies utilizing Htr8 and Jeg3 cell lines confirmed expression of hnRNPL in cellular models of human trophoblasts. These studies [support] coordinated regulation of hnRNPL during the normal developmental program in the mammalian embryo and placenta.

Development of the vertebrate embryo requires strict coordination of a highly complex series of signaling cascades, that drive cell proliferation, differentiation, migration, and the general morphogenetic program. Members of the Map kinase signaling pathway are repeatedly required throughout development to activate the downstream effectors, ERK, p38, and JNK. Regulation of these pathways occurs at many levels in the signaling cascade, with the Map3Ks playing an essential role in target selection. The thousand and one amino acid kinases (Taoks) are Map3Ks that have been shown to activate both p38 and JNK and are linked to neurodevelopment in both invertebrate and vertebrate organisms. In vertebrates, there are three Taok paralogs (Taok1, Taok2, and Taok3) which have not yet been ascribed a role in early development. Here we describe the spatiotemporal expression of Taok1, Taok2, and Taok3 in the model organism Xenopus laevis. The X. laevis Tao kinases share roughly 80% identity to each other, with the bulk of the conservation in the kinase domain. Taok1 and Taok3 are highly expressed in pre-gastrula and gastrula stage embryos, with initial expression localized to the animal pole and later expression in the ectoderm and mesoderm. All three Taoks are expressed in the neural and tailbud stages, with overlapping expression in the neural tube, notochord, and many anterior structures (including branchial arches, brain, otic vesicles, and eye). The expression patterns described here provide evidence that the Tao kinases may play a central role in early development, in addition to their function during neural development, and establish a framework to better understand the developmental roles of Tao kinase signaling.

Germline sex determination and differentiation are pivotal processes in reproduction. In Drosophila, sex determination of the germline occurs in primordial germ cells (PGCs), and the sex differentiation of these cells is initiated during embryogenesis. However, the molecular mechanism initiating sex differentiation remains elusive. To address this issue, we identified sex-biased genes using RNA-sequencing data of male and female PGCs. Our research revealed 497 genes that were differentially expressed more than twofold between sexes and expressed at high or moderate levels in either male or female PGCs. Among these genes, we used microarray data of PGCs and whole embryos to select 33 genes, which are predominantly expressed in PGCs compared to the soma, as candidate genes contributing to sex differentiation. Of 497 genes, 13 genes that were differentially expressed more than fourfold between sexes were also selected as candidates. Among the 46 (33 + 13) candidates, we confirmed the sex-biased expression of 15 genes by in situ hybridization and quantitative reverse transcription-polymerase chain reaction (qPCR) analysis. Six and nine genes were predominantly expressed in male and female PGCs, respectively. These results represent a first step toward elucidating the mechanisms that initiate sex differentiation in the germline.

Transcriptional enhanced associate domain (TEAD) transcription factors play important roles in embryonic stem cell (ESC) renewal and differentiation. Four TEAD transcription factors (Tead1, Tead2, Tead3 and Tead4) and their various splice variants have been discovered in mice, but the expression pattern of them during pluripotency state transition is unclear. Here, we investigated the expression of TEADs and their splice variants in mouse ESCs at different pluripotent/differentiating states and adult mouse tissues. Our results preliminarily revealed the diversity and heterogeneity of TEAD family, which is helpful for understanding their overlapping and distinctive functions. Furthermore, a novel splice variant of Tead1 was identified and named Tead1 isoform 4.