Decreased endothelial cell retinoic acid signaling accelerates progression of single ventricle pulmonary arteriovenous malformations
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE312375 | GEO | 2025/12/04
REPOSITORIES: GEO
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Project description:Background: Hereditary hemorrhagic telangiectasia (HHT) is an inherited vascular disorder characterized by arteriovenous malformations (AVMs). Loss-of-function mutations in Activin receptor-like kinase 1 (ALK1) cause type 2 HHT and Alk1 knockout (KO) mice develop AVMs along with overactivation of VEGFR2/PI3K/AKT signaling. The full spectrum of signaling alterations resulting from ALK1 mutations remains unknown, and more effective and specific inhibitors to combat AVM formation in patients are needed. Methods: Single-cell RNA sequencing of endothelial-specific Alk1 KO mouse retinas and controls was performed. Overexpression of fluid shear stress signaling signatures including the mechanosensitive ion channel PIEZO1 was confirmed in mouse and human HHT2 lesions. Genetic and pharmacological PIEZO1 inhibition was tested in Alk1 KO mice, along with downstream PIEZO1 signaling. Results: A cluster of Alk1 mutant endothelial cells with altered arterio-venous identity overexpressed pathways related to fluid shear stress, hypoxia, inflammation, cell cycle and VEGFR2/PI3K/AKT signaling. Piezo1 deletion and pharmacological inhibition in Alk1-deficient mice mitigated AVM formation, whereas Piezo1 overexpression enhanced AVM formation induced by ALK1 ligand blockade. Mechanistically, PIEZO1 inhibition reduced elevated VEGFR2/AKT, ERK5-p62-KLF4, eNOS, hypoxia, proliferation and inflammation in ALK1 deficient endothelium. Conclusions: PIEZO1 expression and signaling are elevated in HHT2. PIEZO1 blockade reduces AVM formation and alleviates cellular and molecular hallmarks of ALK1-deficient cells. This finding provides new insights into the mechanistic underpinnings of ALK1-related vascular diseases and identifies potential therapeutic targets to prevent AVMs.
2025-07-18 | GSE298122 | GEO
Project description:Vascular networks form, remodel and mature under the influence of both fluid shear stress (FSS) and soluble factors. Physiological FSS promotes and maintains vascular stability via synergy with Bone Morphogenic Protein 9 (BMP9) and BMP10. Conversely, mutation of the BMP receptors ALK1, Endoglin or the downstream effector SMAD4 leads to Hereditary Hemorrhagic Telangiectasia (HHT), characterized by fragile and leaky arterial-venous malformations (AVMs). But how endothelial cells (EC) integrate FSS and BMP signals in vascular development and homeostasis, and how mutations give rise to vascular malformations is not well understood. Here, we aimed to elucidate the mechanism of synergy between fluid shear stress and SMAD signaling in vascular stability and its failure in HHT. We have now found that loss of Smad4 increases ECs’ sensitivity to flow by lowering the FSS set point with resulting AVMs exhibiting features of excessive flow-mediated morphological responses. Mechanistically, loss of Smad4 disinhibits flow-mediated Klf4-Tie2-PI3K/Akt signaling leading to increased EC proliferation and loss of arterial identity due to Klf4-mediated repression of cyclin dependent Kinase (CDK) inhibitors, CDKN2A and CDKN2B. Thus, AVMs caused by Smad4 deletion are characterized by chronic high flow remodeling with excessive EC proliferation and loss of arterial identity as triggering events.
2023-07-03 | GSE232443 | GEO
Project description:Decreased endothelial cell retinoic acid signaling accelerates progression of single ventricle pulmonary arteriovenous malformations
| PRJNA1373191 | ENA
Project description:To identify potential biological targets of the TGFβ pathway involved in AVM formation, we performed RNA-seq on endothelial cells (ECs) isolated from a Smad4 inducible, EC specific knockout (Smad4-iECKO; Smad4f/f;Cdh5-CreERT2) mouse model that develops retinal AVMs.
2018-12-18 | GSE116230 | GEO
Project description:Purpose: Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal dominant vascular disorder characterized by arteriovenous malformations (AVMs). Over 90% of HHT patients carry heterozygous loss-of-function mutations in Transforming Growth Factor-beta (TGFb) signaling components activin receptor-like kinase 1 (ACVRL1/ALK1), endoglin (ENG), or mothers against decapentaplegic homolog 4 (SMAD4). Brain AVMs can be lethal for HHT patients. Here, we use an inducible endothelial (EC)-specific mouse line to investigate brain AVMs characteristics in Alk1-, Eng-, and Smad4-HHT mouse models. Angiopientin-2 (Ang2) inhibition diminishes HHT associated cerebral vascular defects. We aim to identify the shared transcriptional changes in brain ECs between these three HHT types, and provide insights for transcriptional changes upon Ang2 inhibition. Methods: ECs were isolated from brains of both WT and HHT mutant mice at postnatal day 7 (P7) for Smad4 and Eng models, P6 for Alk1 model. Total RNA was extracted from isolated brain ECs and quantified using Qubit RNA High Sensitivity Assay Kit. RNA integrity was determined using the Bioanalyzer RNA 6000 Nano assay kit. RNA library construction was performed with the TruSeq RNA Library Prep Kit v2 from Illumina. The resulting mRNA library was quantified using Qubit dsDNA High Sensitivity Assay Kit and verified using the Bioanalyzer DNA1000 assay kit. Verified samples were sequenced using the NextSeq 500/550 High Output Kit v2.5 (150 Cycles) on a Nextseq 550 system. Sequenced reads were aligned to the mouse (mm10) reference genome with RNA-seq alignment tool (version 2.0.1). The aligned reads were used to quantify mRNA expression and determine differentially expressed genes using the RNA-seq Differential Expression tool (version 1.0.1). Both alignment and differential expression analysis were performed using the tools in the BaseSpace Sequence Hub. Results: We identified 5509, 5381, and 2663 differentially expressed genes in Smad4, Alk1, and Eng HHT models respectively. Also, Ang2 inhibition mainly funcioned through angiogenesis and cell migration processes to normalize cerebrovascular defects in Smad4-HHT model. Conclusions: A common but unique pro-angiogenic program among all HHT models included 14 consistent upregulated and 5 consistent downregulated angiogic genes. Also, Ang2 inhibition mainly funcioned through angiogenesis and cell migration processes to normalize cerebrovascular defects in Smad4-HHT model.
2023-05-19 | GSE197105 | GEO
Project description:Mutations of SMAD family member 4 (Smad4) gene caused Hereditary Hemorrhagic Telangiectasia (HHT). It was believed that bleeding disorders were caused by arteriovenous malformation in this syndrome. Although several studies indicated dysfunction of platelets from HHT patient, the role(s) of smad4 in platelet function has not been examined. In this study, using megakaryocyte/platelet-specific Smad4-deficient mice, we investigated the physiological function of Smad4 in platelet activation and the underlying mechanism. Microarray data demonstrated that the level of mRNA for multiple genes changed in Smad4 deficient platelet. For microarray analysis, total mRNA was extracted from washed platelets from Smad4f/f or Smad4M-bM-^HM-^R/M-bM-^HM-^R mice (for each group, n=6). mRNA was labeled and hybridized to Affymetrix Mouse Genome 430 2.0 chips according to manufacturer's instructions (Affymetrix).
2013-01-29 | E-GEOD-43814 | biostudies-arrayexpress
Project description:Although mitochondrial activity is critical for angiogenesis, its mechanism is not entirely clear. Here, we investigate the angiogenic functions of three separate nuclear genes that encode for mitochondrial proteins, including mitochondrial transcriptional factor (TFAM), respiratory complex IV component (COX10), and a mitochondrial redox protein thioredoxin 2 (TRX2), which are responsible for distinct mitochondrial functions. We aim to investigate if mitochondrial activities regulate common endothelial cell (EC) signaling pathways during angiogenesis. The silencing of Tfam, Cox10, or Trx2 in an in vitro 3D sprouting assay attenuates EC sprouting, which correlated with reduced EC proliferation but not with ROS generation or EC apoptosis. Mice with an inducible deletion of Tfam, Cox10, or Trx2 exhibit retarded retinal vessel growth without penetration into the deep plexi at early ages (P5-P12). The three mutant mice develop arteriovenous malformations (AVM) with microaneurysm formation in the microvessels at advanced ages (P12-P30); the hypovasculature and microaneurysm phenotypes resemble that of aged human retinas and human primitive retinal vascular abnormalities such as Coats’ disease, Leber’s military aneurysms and familial exudative vitreoretinopathy. Single-cell RNA-seq analyses of retinal ECs suggest that the three mutant mice have common EC clusters with reduced gene expressions in anion transporters, actin organization, extracellular matrix, and angiogenesis. These EC clusters also have increased gene expressions in endothelial-mesenchymal transition and arterial markers, correlating with enhanced TGFbR signaling in Tfam, Cox10, or Trx2-deficient mice. Importantly, pharmacological blockade by TGFbR inhibitors attenuated retinal vessel growth retardation and AVM formation in all three mutant mice. Our study demonstrates that mitochondrial dysfunction induces TGF-b receptor-mediated arteriovenous malformations and microaneurysm formation in mouse retinas, and provide a novel model and therapeutic intervention for human primitive retinal vascular abnormalities, which are characterized by retinal vascular malformations and are associated with many pathological complications such as diabetes and hypertension that can result in vision loss.
2022-10-11 | GSE172230 | GEO
Project description:Mutations of SMAD family member 4 (Smad4) gene caused Hereditary Hemorrhagic Telangiectasia (HHT). It was believed that bleeding disorders were caused by arteriovenous malformation in this syndrome. Although several studies indicated dysfunction of platelets from HHT patient, the role(s) of smad4 in platelet function has not been examined. In this study, using megakaryocyte/platelet-specific Smad4-deficient mice, we investigated the physiological function of Smad4 in platelet activation and the underlying mechanism. Microarray data demonstrated that the level of mRNA for multiple genes changed in Smad4 deficient platelet.
2013-01-29 | GSE43814 | GEO
Project description:Distinct endothelial cell cycle states (early G1 vs. late G1) provide different “windows of opportunity” to enable the differential expression of genes that regulate venous and arterial specification, respectively. Endothelial cell cycle control and arterial-venous identities are disrupted in vascular malformations including arteriovenous (AV) shunts which is a hallmark of hereditary hemorrhagic telangiectasia (HHT). We show how endothelial cell late G1 arrest induced by Palbociclib modulates the expression of genes regulating arterio-venous identity and prevents AVM development induced by BMP9/10 inhibition.
2023-12-31 | GSE245197 | GEO
Project description:BMP9 signaling has been implicated in hereditary hemorrhagic telangiectasia and vascular remodeling, acting via the HHT target genes, endoglin and ALK1. This study sought to identify endothelial BMP9-regulated proteins that could affect the HHT phenotype. Gene ontology analysis of cDNA microarray data obtained following BMP9 treatment of primary human endothelial cells indicated regulation of chemokine, adhesion, and inflammation pathways. The sample set is comprised of three biological replicate control human dermal microvascular endothelial cells, and three treated (5 ng/ml human recombinant BMP9) biological replicate human dermal microvascular endothelial cells
2012-09-19 | E-GEOD-40960 | biostudies-arrayexpress