Browse
Submit Data
Databases
API
Help

Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

54 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Deletion of Scap in Alveolar Type II Cells Influences Lung Lipid Homeostasis and Identifies a Compensatory Role for Pulmonary Lipofibroblasts

ABSTRACT: 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.

ORGANISM(S): Mus musculus

SUBMITTER: Yan Xu

PROVIDER: E-GEOD-26496 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Json Xml

Similar Datasets

Deletion of Scap in Alveolar Type II Cells Influences Lung Lipid Homeostasis and Identifies a Compensatory Role for Pulmonary Lipofibroblasts

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.

2011-01-08 | GSE26496 | GEO

Examination of hepatic SREBP-2 binding using ChIP-Seq

Project description:Sterol regulatory element binding proteins (SREBPs) are key transcriptional regulators of lipid metabolism. To define functional differences between the three mammalian SREBPs we are using genome-wide ChIP-seq with isoform-specific antibodies and chromatin from select tissues of mice challenged with different dietary conditions that enrich for specific SREBPs. We show hepatic SREBP-2 binds preferentially to two different gene-proximal motifs. Gene ontology analyses suggests SREBP-2 targets lipid metabolic processes as expected but apoptosis and autophagy gene categories were also enriched. We show SREBP-2 directly activates autophagy genes during cell sterol depletion, conditions known to induce both autophagy and nuclear SREBP-2 levels. Additionally, SREBP-2 knockdown during nutrient depletion decreased autophagosome formation and lipid droplet association of the autophagosome targeting protein LC3. Thus, the lipid droplet could be viewed as a third source of cellular cholesterol, which along with sterol synthesis and uptake, is also regulated by SREBP-2. Examination of hepatic SREBP-2 binding using ChIP-Seq. One ChIP-Seq dataset and one IgG control.

2011-03-22 | E-GEOD-28082 | biostudies-arrayexpress

Examination of hepatic SREBP-2 binding using ChIP-Seq

2011-03-23 | GSE28082 | GEO

Activation of SREBP in Alveolar Type II Cells Enhances Lipogenesis Causing Pulmonary Lipotoxicity

Project description:Background: Lung function is dependent upon the precise regulation of the synthesis, storage, and catabolism of tissue and alveolar lipids. Results: Activation of SREBP (Sterol Response Element Binding Protein) induced lipogenesis in alveolar epithelial cells, causing neutral lipid accumulation, lung inflammation, and tissue remodeling. Conclusions: The accumulation of neutral lipids in type II epithelial cells and alveolar macrophages caused lung inflammation, consistent with findings in lipid storage disorders. Significance: Pulmonary lipotoxicity may contribute to the pathogenesis of lung dysfunction associated with diabetes, obesity, and other metabolic disorders.

2012-03-01 | GSE31797 | GEO

Transcriptional responses of Mycobacterium tuberculosis to lung surfactant

Project description:This study uses microarray analyses to examine gene expression profiles for Mycobacterium tuberculosis (Mtb) induced by exposure in vitro to bovine lung surfactant preparations that vary in apoprotein content: (i) whole lung surfactant (WLS) containing the complete mix of endogenous lipids and surfactant proteins (SP)-A, -B, -C, and -D; (ii) extracted lung surfactant (CLSE) containing lipids plus SP-B and -C; (iii) column-purified surfactant lipids (PPL) containing no apoproteins, and (iv) purified human SP-A. Exposure to WLS evoked a multitude of transcriptional responses in Mtb, with 52 genes up-regulated and 23 genes down-regulated at 30 min exposure, plus 146 genes up-regulated and 27 genes down-regulated at 2 h. Notably, WLS rapidly induced several membrane-associated lipases that presumptively act on surfactant lipids as substrates, and a large number of genes involved in the synthesis of phthiocerol dimycocerosate (PDIM), a cell wall component known to be important in macrophage interactions and Mtb virulence. Exposure of Mtb to CLSE, PPL, or purified SP-A caused a substantially weaker transcriptional response (≤ 20 genes were induced) suggesting that interactions among multiple lipid-protein components of WLS may contribute to its effects on Mtb transcription.

2009-06-01 | GSE14005 | GEO

Activation of SREBP in Alveolar Type II Cells Enhances Lipogenesis Causing Pulmonary Lipotoxicity

2012-03-01 | E-GEOD-31797 | biostudies-arrayexpress

Pancreatic ductal adenocarcinoma tumor growth requires SREBP pathway activity

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

Combined analysis of oligonucleotide microarray data from transgenic and knockout mice identifies direct SREBP target genes [MG_U74Av2]

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

Combined analysis of oligonucleotide microarray data from transgenic and knockout mice identifies direct SREBP target genes [MG_U74Cv2]

2017-08-05 | GSE102258 | GEO

Combined analysis of oligonucleotide microarray data from transgenic and knockout mice identifies direct SREBP target genes [MG_U74Bv2]

2017-08-05 | GSE102257 | GEO