Project description:Nuclear speckles are conserved, membrane-less organelles linked to various post-transcriptional processes. Here, we examined their roles in human cells by engineered, acute removal of SON and SRRM2, two conserved speckle core components characterized by intrinsically disordered regions (IDRs). Their removal results in a significant downregulation of GC-rich genes with short introns clustered within GC-rich isochores, caused by inefficient and chaotic splicing; in contrast, expression or splicing of genes outside these isochores remains unaffected. Comparative analysis across eukaryotes, from fungi to mammals, reveals that both GC-rich isochores and speckles are found exclusively in amniotes; moreover, the IDRs of SON have undergone notable expansion in the latter. Together, these findings suggest that the expansion of IDRs in vertebrates facilitated an increase in GC content by creating a condensate essential for splicing the by-products of this process: GC-rich, levelled exon-intron architectures.
Project description:The study aims to explore gene expression changes associated with commerically available germ cell lines, GC-1 (spg) and GC-2 (spd)ts
Project description:Relative protein quantification of RPL4 and RPL39L in non-ribosome, 40S, 60S and ribosome fractions by PRM;Absolute quantification of RPL39 and RPL39L levels in ribosomes of GC-1 wild type cell, and RPL39L-IRES-eGFP-overexpressed RibosomeCore-/Y GC-1 cells with or without dox-induced expression of RPL39 by PRM. Bovine serum albumin (BSA) as a negative control.
Project description:Our previous study reported that IGFBP7 plays a role in maintaining mRNA stability of oncogenic lncRNA UBE2CP3 by RNA-RNA interaction. Clinical cohort studies had implied an oncogenic role of IGFBP7 in GC. However, the molecular mechanism of IGFBP7 in driving gastric cancer (GC) progression remains unknown. In this study, clinical analysis based on two independent cohort showed that IGFBP7 was positively associated with poor prognosis and macrophage infiltration in GC. Loss-of-function studies confirmed the oncogenic properties of IGFBP7 in regulating GC cell proliferation and invasion. Mechanismly, IGFBP7 was induced by epithelial-to-mesenchymal transition (EMT) signaling, since its expression was increased by TGF-beta treatment and reduced by overexpression of OVOL2 in GC. RNA sequencing, qRT-PCR, ELISA assay showed that IGFBP7 positively regulating FGF2 expression and secretion. Transcriptome analysis revealed that FGFR1 was downregulated in M1 macrophages but upregulated in M2 macrophages. Exogenous recombinant IGFBP7 protein in macrophages and GC cells further identified that IGFBP7 promotes macrophage polarization towards to a M2/TAM phenotype via FGF2/FGFR1/PI3K/AKT axis. Our finding highlights that IGFBP7 promotes GC by enhancing TAM infiltration through FGF2/FGFR1/PI3K/AKT axis.
Project description:Following infection or vaccination, activated B cells at extrafollicular sites or within germinal centers (GCs) undergo vigorous clonal proliferation. Proliferating lymphocytes have been shown to undertake lactate dehydrogenase A (LDHA)-dependent aerobic glycolysis; however, the specific role of this metabolic pathway in a B cell transitioning from a naïve to a highly proliferative, activated state remains poorly defined. Here, we deleted LDHA in a stage- and cell-specific manner. We find that ablation of LDHA in a naïve B cell did not profoundly affect its ability to undergo a T cell-independent extrafollicular B cell response. On the other hand, LDHA-deleted naïve B cells had a severe defect in the capacities to form GCs and mount GC-dependent antibody responses. In addition, loss of LDHA in T cells severely compromised B cell-dependent immune responses. Strikingly, when LDHA was deleted in activated, as opposed to naïve, B cells, there were only minimal effects on the GC reaction and in the generation of high-affinity antibodies. These findings strongly suggest that naïve and activated B cells have distinct metabolic requirements that are further regulated by niche and cellular interactions.