Gene expression changes in brain vascularture in Notch3 knockout mice
Ontology highlight
ABSTRACT: Vascular smooth muscle cells (VSMC) are important for contraction, blood flow distribution and regulation of blood vessel diameter, but to what extent they contribute to the integrity of blood vessels and blood-brain barrier function is less well understood. In this report, we explored the impact of the progressive loss of VSMC in the Notch3-/- mouse on blood vessel integrity in the central nervous system To explore the molecular consequences of the VSMC phenotype in Notch3-/- mice, we performed genome-wide transcriptional profiling of the brain vasculature in mutants and littermate controls using Affymetrix Mouse Genome 430 2.0 Array. Three Notch3 knockout and three littermate control mice at age of 2 months were used to profile the transcriptomes. Total RNA was extracted from cerebral and cerebellar microvascular fragments and hyrbridized separately on the Mouse Genome 430 2.0 Array according to standard procedures.
Project description:Vascular smooth muscle cells (VSMC) are important for contraction, blood flow distribution and regulation of blood vessel diameter, but to what extent they contribute to the integrity of blood vessels and blood-brain barrier function is less well understood. In this report, we explored the impact of the progressive loss of VSMC in the Notch3-/- mouse on blood vessel integrity in the central nervous system To explore the molecular consequences of the VSMC phenotype in Notch3-/- mice, we performed genome-wide transcriptional profiling of the brain vasculature in mutants and littermate controls using Affymetrix Mouse Genome 430 2.0 Array.
Project description:While most cases of vascular dementia represent complex interactions between host genetics and environmental factors, mendelian forms of vascular dementia also exist. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), is a mendelian disease characterized by progressive vascular deterioration, cognitive deficits, and strokes. Mutations in the NOTCH3 receptor underlies the pathologies in CADASIL. NOTCH3 is primarily expressed in vascular smooth muscle cell (vSMC) and its’ expression is critical for differentiation and functional integrity of arterial vSMCs, albeit through unclear mechanism(s). To elucidate the contribution of NOTCH3 in the maintenance of cerebral vascular architecture and function, we performed micro-computed tomography (micro-CT) on the brains of aged Notch3-deficient animals. Micro-CT assessment of the cerebral vasculature architecture showed significant abnormalities including severe vessel dilation and tortuosity (dolicoectasia) of the middle cerebral artery and its branches in the Notch3-/- compared to aged-match controls. To identify the molecular pathway from NOTCH3 dysregulation to the observed cerebral vascular dysfunction, we performed single-cell RNASeq on cerebral arteries isolated from young (4w) and old (104w) Notch3-/- animals. Evaluation of the vSMC-specific transcriptomes indicated significant loss of proteins associated with muscle contraction and increased extracellular matrix production in animals that lack NOTCH3. Using a combination of immunofluorescence microscopy and in vitro functional assays, we confirmed that continued expression of Notch3 is a critical requirement for maintenance of vSMC contractile function. Impaired contractility also affected flow of cerebrospinal fluid in the parenchyma of Notch3-/- . MRI and behavioral assessments were performed in the Notch3-/- animals to elucidate the relationship between impaired vascular contractility to cognitive function. Taken together these findings link the molecular dysfunction of NOTCH3 through its regulation of vascular contractility and cerebral vessel architecture to altered neurological function and clarify the molecular pathways to cellular pathology of Notch3 driven dementias.
Project description:Heart ventricle tissue was harvested from Trex1/RAG2 DKO mice and from Trex1WT/RAG2KO littermate controls. RNA was extracted, and an Affymetrix Mouse 430 2.0 gene chip analysis was performed.
Project description:Glomerular podocyte cells are critical for the function of the renal ultrafiltration barrier. The highly specialized cell-cell junction of podocytes, the slit diaphragm, has a central role in the filtration barrier. Dendrin is a poorly characterized cytosolic component of the slit diaphragm in where it interacts with nephrin and Cd2ap. In this study, we have generated a dendrin knockout mouse line and explored the molecular interactions of dendrin. Dendrin-deficient mice were viable, fertile and had normal life span. To reveal the glomerular gene expression changes in the dendrin knockout mouse, Affymetrix Mouse Genome 430 2.0 Array were used to profiling the dendrin knockout and control glomeruli. Three dendrin knockout and three littermate control mice at age of 13 months were used to profile glomerular transcriptomes. Total glomerular RNA was extracted and hyrbridized on the Mouse Genome 430 2.0 Array according to standard procedures.
Project description:The heart depends on a functional vasculature for oxygenation and transport of nutrients, and while occlusion of the coronary arteries can lead to myocardial infarction, it remains less explored how a more subtle primary impairment of the vasculature can indirectly affect cardiac function and morphology of the heart. Notch3-deficiency causes vascular smooth muscle cell (VSMC) loss in the vasculature but the consequences for the heart remain largely elusive. Here, we demonstrate that Notch3-/- mice have enlarged hearts with left ventricular hypertrophy and mild fibrosis. Cardiomyocytes were hypertrophic but not hyperproliferative, and the expression of several cardiomyocyte markers, including TnT2, MYH6, MYH7 and Actn2, was altered. Furthermore, expression of genes regulating the metabolic status of the heart was altered: both Pdk4 and Cd36 were downregulated, indicating a metabolic switch from fatty acid oxidation to glucose consumption. Notch3-/- mice furthermore showed lower liver lipid content. Notch3 was expressed in heart VSMC and pericytes but not in cardiomyocytes, suggesting that a perturbation of Notch signalling in VSMC and pericytes indirectly impairs the cardiomyocytes. In keeping with this, Pdgfbret/ret mice, characterized by reduced numbers of VSMC and pericytes, showed left ventricular and cardiomyocyte hypertrophy. In conclusion, we demonstrate that reduced NOTCH3 or PDGFB signalling in vascular mural cells lead to cardiomyocyte dysfunction.
Project description:Pharmacological activation of the transcription factor PPAR gamma lowers blood pressure and improves glucose tolerance in humans. In contrast, naturally occurring mutations (e.g., P467L, V290M) in the ligand binding domain of PPAR gamma in humans leads to severe insulin resistance and early-onset hypertension. Experimental evidence, including whole genome expression profiling, suggests that these mutant versions of PPAR gamma act in a dominant negative manner. Because PPAR gamma is expressed in a variety of cell types and tissues, we generated a transgenic mouse model (SP467L) specifically targeting dominant negative PPAR gamma to the vascular smooth muscle cells in order to determine the action of PPAR gamma in the blood vessel independent of its systemic metabolic actions. In the data set provided herein, we examined the gene expression profile in thoracic aorta from SP467L mice and their control littermates using the Affymetrix Mouse Genome 430 2.0 array. We generated transgenic mice specifically targeting expression of mutant dominant negative human PPAR gamma (P467L) to vascular smooth muscle using a smooth muscle-specific promoter (smooth muscle myosin heavy chain or SMMHC). Thoracic aortas were isolated from male transgenic mice and corresponding non-transgenic littermate controls. Total RNA was prepared using conventional methods and quality was assessed using the Bioanalyzer 2100 (Agilent Technologies). For the microarray hybridizations, 2 samples from control mice and 3 samples from transgenic mice were used. Each sample was an independent biological replicate generated by pooling total RNA from 6-8 separate mouse aortas. All procedures were conducted at the University of Iowa DNA Core facility using standard Affymetrix protocols. In brief, approximately 3-5 ug of total RNA was used as input to a one-step amplification procedure to generate biotin-labeled RNA fragments for hybridization to the Affymetrix Mouse Genome 430 2.0 array.
Project description:Pharmacological activation of the transcription factor PPAR gamma lowers blood pressure and improves glucose tolerance in humans. In contrast, naturally occurring mutations (e.g., P467L, V290M) in the ligand binding domain of PPAR gamma in humans leads to severe insulin resistance and early-onset hypertension. Experimental evidence, including whole genome expression profiling, suggests that these mutant versions of PPAR gamma act in a dominant negative manner. Because PPAR gamma is expressed in a variety of cell types and tissues, we generated a transgenic mouse model (SP467L) specifically targeting dominant negative PPAR gamma to the vascular smooth muscle cells in order to determine the action of PPAR gamma in the blood vessel independent of its systemic metabolic actions. In the data set provided herein, we examined the gene expression profile in thoracic aorta from SP467L mice and their control littermates using the Affymetrix Mouse Genome 430 2.0 array.
Project description:Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Wild type (WT), Notch3 (Notch3-/-) and Notch4 (Notch4-/-) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6-72 hours. Ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4-/- compared to WT and Notch3-/-. Significantly greater mean numbers of BALF neutrophils were found in Notch3-/- and Notch4-/- mice compared to WT mice after ozone. Expression of whole lung Tnf was significantly increased after ozone in all genotypes, and was significantly greater in Notch3-/- mice compared to WT. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation. Wild-type, Notch3 knockout, and Notch4 knockout mice at 7-13 weeks of age were exposed continuously to air or 0.3 ppm ozone for 6, 24, or 48 hours. Three biological replicates from individual animals were included in each exposure group from each genotype and samples hybridized to the GeneChip Mouse Genome 430 2.0 array (Affymetrix).