Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [RNA-seq]

ABSTRACT: PDX1 is known as the insulin transcription factor that regulates insulin expression in pancreatic β-cells in response to circulating glucose levels. Our previous study showed PDX1 also acts as a downstream effector that mediates β-cell mTORC1 signaling in the control of whole-body glucose homeostasis in response to stimulation by amino acids (AAs). Here we report that PDX1 has a broad role in AA-mTORC1-regulated transcriptome in β-cells, especially in processes related to β-cell proliferation and function. Mechanistically, mTORC1 phosphorylates PDX1 at S61 in an AA-dependent and rapamycin-sensitive manner. S61 phosphorylation promotes PDX1 protein levels and transcriptional activity. Interestingly, S61 is located within the transactivation domain targeted by monogenic diabetes mutations, which interfere with S61 phosphorylation and PDX1's transcriptional activity. To help understand the role of S61 phosphorylation in vivo, we generated S61A and S61E genomic mutations in mice, mimicking the unphosphorylated and phosphorylated states, respectively. Our results indicate that S61 phosphorylation positively regulates insulin expression and β-cell proliferation, promoting Western diet-induced hyperinsulinemia, obesity, and liver steatosis. These findings reveal the mechanism and roles of AA-mTORC1-PDX1 signaling in the control of pancreatic β-cell proliferation and function under physiological and pathological conditions.

ORGANISM(S): Mus musculus

PROVIDER: GSE278790 | GEO | 2025/12/01

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [ChIP-seq]

Project description:PDX1 is known as the insulin transcription factor that regulates insulin expression in pancreatic β-cells in response to circulating glucose levels. Our previous study showed PDX1 also acts as a downstream effector that mediates β-cell mTORC1 signaling in the control of whole-body glucose homeostasis in response to stimulation by amino acids (AAs). Here we report that PDX1 has a broad role in AA-mTORC1-regulated transcriptome in β-cells, especially in processes related to β-cell proliferation and function. Mechanistically, mTORC1 phosphorylates PDX1 at S61 in an AA-dependent and rapamycin-sensitive manner. S61 phosphorylation promotes PDX1 protein levels and transcriptional activity. Interestingly, S61 is located within the transactivation domain targeted by monogenic diabetes mutations, which interfere with S61 phosphorylation and PDX1's transcriptional activity. To help understand the role of S61 phosphorylation in vivo, we generated S61A and S61E genomic mutations in mice, mimicking the unphosphorylated and phosphorylated states, respectively. Our results indicate that S61 phosphorylation positively regulates insulin expression and β-cell proliferation, promoting Western diet-induced hyperinsulinemia, obesity, and liver steatosis. These findings reveal the mechanism and roles of AA-mTORC1-PDX1 signaling in the control of pancreatic β-cell proliferation and function under physiological and pathological conditions.

2025-12-01 | GSE278789 | GEO

Dynamic regulation of pancreatic β cell function and gene expression by the SND1 coregulator in vitro

Project description:The pancreatic β cell synthesizes, packages, and secretes insulin in response to glucose-stimulation to maintain blood glucose homeostasis. Under diabetic conditions, a subset of β cells fail and lose expression of key transcription factors (TFs) required for insulin secretion. Among these TFs is Pancreatic and duodenal homeobox 1 (Pdx1), which recruits a unique subset of transcriptional coregulators to modulate its activity. Here we describe a novel interacting partner of Pdx1, the Staphylococcal Nuclease and Tudor domain-containing protein (Snd1), which has been shown to facilitate protein-protein interactions and transcriptional control through diverse mechanisms in a variety of tissues. Pdx1:Snd1 interactions were confirmed in rodent β cell lines, mouse islets and human islets. Utilizing CRISPR-Cas9 gene editing technology, we deleted Snd1 from the mouse β cell lines, which revealed numerous differentially expressed genes linked to insulin secretion and cell proliferation, including limited expression of Glp1r. We observed Snd1 deficient β cell lines had reduced cell expansion rates, Glp1r protein levels and limited cAMP accumulation under stimulatory conditions, and further show that acute ablation of Snd1 impaired insulin secretion in rodent and human β cell lines. Lastly, we discovered that PDX1:SND1 interactions were profoundly reduced in human β cells from donors with type 2 diabetes (T2D). These observations suggest the Pdx1:Snd1 complex formation is critical for controlling a subset of genes important for β cell function and is targeted in diabetes pathogenesis

2023-08-22 | GSE240993 | GEO

Phosphoproteomics reveals the GSK3-PDX1 axis as a key pathogenic signaling node in diabetic islets

Project description:Progressive decline of pancreatic beta cell function is central to the pathogenesis of type 2 diabetes. Protein phosphorylation regulates glucose-stimulated insulin secretion from beta cells, but how signaling networks are remodeled in diabetic islets in vivo remains unknown. Using high-sensitivity mass spectrometry-based proteomics we quantified 6,500 proteins and 13,000 phosphopeptides in islets of obese diabetic mice and matched controls, revealing drastic remodeling of key kinase hubs and signaling pathways. Integration with a literature-derived signaling network implicated GSK3 kinase in the control of the beta cell-specific transcription factor PDX1. Deep phosphoproteomic analysis of human islets chronically treated with high glucose demonstrated a conserved glucotoxicity-dependent role of GSK3 kinase in regulating insulin secretion. Remarkably, the ability of beta cells to secrete insulin in response to glucose was rescued almost completely by pharmacological inhibition of GSK3. Thus, our resource enables investigation of mechanisms and drug targets in type 2 diabetes.

2019-03-15 | PXD012671 | Pride

Pancreas-specific Sirt1-deficiency in mice compromises beta-cell function without development of hyperglycemia

Project description:Sirtuin 1 (Sirt1) has been reported to be a critical positive regulator of glucose-stimulated insulin secretion in pancreatic beta-cells. The effects on islet cells and blood glucose levels when Sirt1 is deleted specifically in the pancreas are still unclear.This study examined islet glucose responsiveness, blood glucose levels, pancreatic islet histology and gene expression in Pdx1-Cre;Sirt1(ex4F/F) mice that have loss of function and loss of expression of Sirt1 specifically in the pancreas. We found that in the Pdx1-Cre;Sirt1(ex4F/F) mice, the relative insulin positive area and the islet size distribution were unchanged. However, beta-cells were functionally impaired, presenting with lower glucose-stimulated insulin secretion. This defect was not due to a reduced expression of insulin but was associated with a decreased expression of the glucose transporter Slc2A2/Glut2 and of the Glucagon like peptide-1 receptor (Glp1r) as well as with a marked down regulation of endoplasmic reticulum (ER) chaperones that participate in the Unfolded Protein Response (UPR) pathway. Counter intuitively, the Sirt1-deficient mice did not develop hyperglycemia. Pancreatic polypeptide (PP) cells were the only other islet cells affected, with reduced numbers in the Sirt1-deficient pancreas. This study provides new mechanistic insights showing that beta-cell function in Sirt1-deficient pancreas is affected due to altered glucose sensing and deregulation of the UPR pathway. Interestingly, we uncover a context in which impaired beta-cell function is not accompanied by increased glycemia. This points to a unique compensatory mechanism. Given the reduction in PP, investigation of its role in the control of blood glucose is warranted. To uncover other Sirt1-regulated mechanisms, we performed a gene expression microarray analysis comparing pancreata from the 6 month old Sirt1âdeficient mice to their controls (n=3 per group).

2016-03-01 | E-GEOD-67239 | biostudies-arrayexpress

PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [ChIP-seq]

Project description:PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [ChIP-seq]

| PRJNA1168924 | ENA

PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [RNA-seq]

Project description:PDX1 Phosphorylation Mediates Amino Acid-mTORC1 Signaling in Pancreatic β-Cells [RNA-seq]

| PRJNA1168927 | ENA

NF-kB and Circadian Enhancers Link β-cell Function with Anti-IL1B Therapy [RNA-seq]

Project description:Crosstalk between lineage-determining and signal-dependent transcription factors controls chromatin plasticity within heterogeneous tissues, yet how alterations in these interactions within single cells contribute to disease remains unknown. Here, by profiling chromatin activity in single nuclei of human pancreatic islets, we identified 19 clusters of cells, including β-cell subpopulations defined by differences in accessibility at non-coding cis-regulatory elements (CREs) for the lineage-determining factor pancreatic duodenal homeobox factor 1 (PDX1). Single cells with a high density of PDX1 CREs were enriched in accessible enhancer landscapes driving gene networks controlling nutrient sensing, insulin exocytosis, and circadian rhythms. In contrast, cells with reduced opening at PDX1 CREs had increased accessibility at regulatory elements for pro-inflammatory genes controlled by NF-kB and IL-1β. Genetic deficiency of Pdx1 in mice led to increased chromatin occupancy by the classical NF-κB subunit p65 and glucose intolerance that was more pronounced at the time of day when mice were awake and feeding. Within murine and human islets, PDX1 formed long-range repressive contacts with canonical regions of p65-mediated transcription. Pharmacological inhibition of signaling through the IL-1β receptor, an abundant β-cell target of p65, enhanced glucose-dependent insulin secretion in Pdx1-deficient β cells. Together, our single-cell epigenomic analyses provide a rationale to antagonize NF-kB signaling as an insulinotropic therapy for β-cell failure and diabetes.

2023-04-03 | GSE214677 | GEO

NF-kB and Circadian Enhancers Link β-cell Function with Anti-IL1B Therapy [Bulk ATAC-seq]

2023-04-03 | GSE214676 | GEO

NF-kB and Circadian Enhancers Link β-cell Function with Anti-IL1B Therapy [scATAC-seq]

2023-04-03 | GSE214675 | GEO

NF-kB and Circadian Enhancers Link β-cell Function with Anti-IL1B Therapy [ChIP-Seq]

2023-10-30 | GSE246507 | GEO