SREBP signaling is essential for effective B cell responses and memory formation
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE206016 | GEO | 2022/06/30
REPOSITORIES: GEO
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Project description:Tumor growth outstrips local nutrient supply, making metabolic reprogramming a necessary component of oncogenesis and cancer progression. The supply of lipids such as cholesterol and fatty acids is required for continued tumor cell division. Sterol regulatory element-binding protein (SREBP) transcription factors control cellular lipid homeostasis by activating genes required for cholesterol and fatty acid synthesis and uptake. SREBPs have been implicated in the progression of multiple cancers, including glioblastoma, breast, colon, liver and prostate. However, the role the SREBP pathway and its central regulator SREBP cleavage activating protein (SCAP) in pancreatic ductal adenocarcinoma (PDAC) has not been studied in detail. Here, we demonstrate that SREBP target genes are upregulated in PDAC tumors, and SREBPs are upregulated in patient-derived PDAC cell lines under low serum conditions that mimic the tumor microenvironment. Chemical or genetic inhibition of the SREBP pathway prevented PDAC cell growth under low serum conditions due to a lack of lipid supply. Using subcutaneous and orthotopic xenograft models, we showed that SCAP is required for PDAC tumor growth. Pancreas-specific knockout of Scap had no effect on mouse pancreas development or function, allowing examination of the role for Scap in the murine KPC model of PDAC. Notably, heterozygous loss of Scap significantly prolonged survival in KPC mice, and homozygous loss of Scap impaired PDAC tumor inception. Collectively, these results demonstrate that SCAP and SREBP pathway activity are essential for PDAC cell and tumor growth in vitro and in vivo, identifying SCAP as a potential therapeutic target for PDAC.
2024-10-09 | GSE235100 | GEO
Project description:The sterol-regulatory element binding protein (SREBP) transcription factors are central transcriptional regulators of sterol- and fatty acid metabolism. Using a suite of human haploid genetic screens, we identify the SREBP Regulating Gene (SPRING; C12ORF49) as a novel regulator of this pathway. SPRING is a glycosylated Golgi-resident membrane protein. Genetic ablation of SPRING in human Hap1 cells, murine Hepa1-6 hepatoma cells, and in primary murine hepatocytes leads to a marked reduction in SREBP signaling. In mice, deletion of Spring results in embryonic lethality. However, we show that adenoviral-mediated silencing of hepatic Spring expression also attenuates the SREBP response. Mechanistically, we demonstrate that attenuated SREBP signaling in SPRINGKO cells is a result of reduced SREBP cleavage-activating protein (SCAP) and its mislocalization. Whereas in control cells SCAP cycles between the ER and the Golgi in a sterol-dependent manner, in SPRINGKO cells SCAP is trapped in the Golgi irrespective of the cellular sterol status. Consistent with limited functional SCAP in SPRINGKO cells, reintroducing SCAP restores SREBP-dependent signaling, cholesterol biosynthesis, and lipoprotein uptake. Consistent with SREBP signaling being required for cell growth and proliferation, a wide range of human tumor cell lines display dependency on SPRING expression. In conclusion, we identify SPRING as a previously unrecognized determinant of the SREBP pathway that is essential for proper SCAP function.
2020-01-23 | GSE143530 | GEO
Project description:The chemokines CXCL13 and CXCL12 are reported to be important for the germinal center reaction. Since CXCL12-deficient mice are embryonically lethal, here we took advantage of the Cxcl13-Cre/TdTomato mouse models to genetically ablate CXCL12 from B cell-interacting reticular cells and examine the molecular consequence on germinal center B cells. Spatial segregation of follicular dendritic cells, germinal center B cells and follicular helper T cells is impaired in Cxcl13-Cre/TdTomato Cxcl12fl/fl mice. Single cell transcriptomic analysis revealed that all germinal center B cell subsets (corresponding to distinct stages of the germinal center response) are present in draining lymph nodes of immunized CXCL12-conditionally deficient mice. While most transcriptional regulators of the germinal center response are unperturbed by the genetic perturbation of CXCL12, Bach2 levels were elevated in germinal center B cells from lymph nodes of Cxcl12fl/fl mice. Moreover, single cell B cell receptor sequencing revealed that germinal center B cells in Cxcl13-Cre/TdTomato Cxcl12fl/fl mice harbour a lower mutational burden when compared to germinal center B cells isolated from immunized control mice. Gene expression profiles were validated by flow cytometry and suggest that the provision of CXCL12 by reticular cells governs efficient germinal center responses.
2020-05-12 | E-MTAB-8454 | biostudies-arrayexpress
Project description:The synthesis of fatty acids and cholesterol is regulated by three membrane-bound transcription factors: sterol regulatory element-binding proteins (SREBP)-1a, -1c, and -2. Their function in liver has been characterized in transgenic mice that overexpress each SREBP isoform and in mice that lack all three nuclear SREBPs because of gene knockout of SREBP cleavage-activating protein (SCAP) required for nuclear localization of SREBPs. Here, we use oligonucleotide arrays hybridized with RNA from livers of three lines of mice (transgenic for SREBP-1a, transgenic for SREBP-2, and knockout for SCAP) to identify genes that are likely to be direct targets of SREBPs in liver. Application of stringent combinatorial criteria to the transgenic/knockout approach allows identification of genes whose activities are likely controlled directly by the SREBPs.
2017-08-05 | GSE102258 | GEO
Project description:The synthesis of fatty acids and cholesterol is regulated by three membrane-bound transcription factors: sterol regulatory element-binding proteins (SREBP)-1a, -1c, and -2. Their function in liver has been characterized in transgenic mice that overexpress each SREBP isoform and in mice that lack all three nuclear SREBPs because of gene knockout of SREBP cleavage-activating protein (SCAP) required for nuclear localization of SREBPs. Here, we use oligonucleotide arrays hybridized with RNA from livers of three lines of mice (transgenic for SREBP-1a, transgenic for SREBP-2, and knockout for SCAP) to identify genes that are likely to be direct targets of SREBPs in liver. Application of stringent combinatorial criteria to the transgenic/knockout approach allows identification of genes whose activities are likely controlled directly by the SREBPs.
2017-08-05 | GSE102257 | GEO
Project description:The synthesis of fatty acids and cholesterol is regulated by three membrane-bound transcription factors: sterol regulatory element-binding proteins (SREBP)-1a, -1c, and -2. Their function in liver has been characterized in transgenic mice that overexpress each SREBP isoform and in mice that lack all three nuclear SREBPs because of gene knockout of SREBP cleavage-activating protein (SCAP) required for nuclear localization of SREBPs. Here, we use oligonucleotide arrays hybridized with RNA from livers of three lines of mice (transgenic for SREBP-1a, transgenic for SREBP-2, and knockout for SCAP) to identify genes that are likely to be direct targets of SREBPs in liver. Application of stringent combinatorial criteria to the transgenic/knockout approach allows identification of genes whose activities are likely controlled directly by the SREBPs.
2017-08-05 | GSE102256 | GEO
Project description:Comparison of the germinal center B cell receptor repertoire in Cxcl13-Cre/TdTom EYFP (control) and Cxcl13-Cre/TdTom EYFP Cxcl12fl/fl mice on day following subcutaneous immunization with NP-KLH.
2020-05-12 | E-MTAB-8904 | biostudies-arrayexpress
Project description:Splenic B cells isolated from SCAP+/+ CD19-Cre (WT) and SCAPfl/fl CD19-Cre (KO) mice were stimulated with LPS or anti-CD40 for 24 and 48 hours. Cells were then analyzed by metabolomics. Metabolomics reveals global metabolic changes in SCAP deficient B cells.
2022-10-19 | ST002322 | MetabolomicsWorkbench
Project description:Pulmonary function after birth is dependent upon surfactant lipids that reduce surface tension in the alveoli. The sterol-responsive element-binding proteins (SREBPs) are transcription factors regulating expression of genes controlling lipid homeostasis in many tissues. To identify the role of SREBPs in the lung, we conditionally deleted the SREBP cleavage-activating protein gene, Scap, in respiratory epithelial cells (Scap∆/∆) in vivo. Prior to birth (E18.5), deletion of Scap decreased the expression of both SREBPs and a number of genes regulating fatty acid and cholesterol metabolism. Nevertheless, Scap∆/∆ mice survived postnatally, surfactant and lung tissue lipids being substantially normalized in adult Scap∆/∆ mice. Although phospholipid synthesis was decreased in type II cells from adult Scap∆/∆ mice, lipid storage, synthesis, and transfer by lung lipofibroblasts were increased. mRNA microarray data indicated that SCAP influenced two major gene networks, one regulating lipid metabolism and the other stress-related responses. Deletion of the SCAP/SREBP pathway in respiratory epithelial cells altered lung lipid homeostasis and induced compensatory lipid accumulation and synthesis in lung lipofibroblasts. To identify the role of SREBPs in the lung, we conditionally deleted the SREBP cleavage-activating protein gene, Scap, in respiratory epithelial cells (Scap∆/∆) in vivo.Lung cRNA was hybridized to the murine genome MOE430 V2 chips.
2011-01-08 | E-GEOD-26496 | biostudies-arrayexpress
Project description:To investigate the role of SREBP signaling in B cell activation, we stimulated SCAP+/+CD19Cre/+ (WT) and SCAPfl/fl CD19Cre/+ (KO) B cells with LPS, anti-CD40 or anti-IgM for 24 hrs and performed RNA sequencing to identifiy the differences.
2022-06-30 | GSE204913 | GEO