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Principal Investigator: Andy Y Shih
Organization: SEATTLE CHILDREN'S HOSPITAL
Fiscal Year: 2024
Award: $683,367
Funding agency: National Institute of Neurological Disorders and Stroke
The constriction and regression of brain capillaries is well documented in Alzheimer’s disease and Vascular Contributions to Cognitive Impairment and Dementia (AD/VCID). There is strong preclinical and clinical evidence to suggest that contraction of pericytes leads to abnormal capillary constriction, and that this contributes to cerebral hypoperfusion in AD/VCID. However, rigorous approaches to incorporate pericyte-driven hypoperfusion into AD/VCID models remain limited. This R61/R33 project will develop a novel chemogenetic model for cerebral hypoperfusion that involves adjustable control of CNS capillary flow by engaging pericyte contractile dynamics. We demonstrate feasibility of the approach by expressing in CNS pericytes, Gq-DREADDs (Designer Receptors Activated Only by Designer Drugs), an engineered G protein-coupled receptor that can be selectively and potently activated by ligands with little to no other biological activity. Using this “lock and key” approach, we achieved effective chemogenetic control of pericyte contractility and modulation of brain capillary flow and tissue oxygen levels in vivo. However, some limitations need to be overcome for broader utility of the model. Crossing Atp13a5-2A-CreER-IRES- tdTomato mice with floxed Gq-DREADD mice led to inefficient gene recombination with routine tamoxifen dosing, and the need to cross-breed mice becomes a burden for combining the hypoperfusion model with other disease models. Therefore, this project will develop Pericyte DREADD knock-in mice to circumvent the need for Cre-lox recombination. In the R61 phase, Pericyte Gq-DREADD mice will be created for chemogenetic contraction of brain pericytes in vivo. We will determine optimal dosing for systemic administration of DREADD agonist to achieve chronic blood flow reduction to ~50-75% of basal levels in adult and aged mice. Microvascular perfusion in gray and white matter will be assessed with longitudinal deep two-photon imaging and followed by detailed histology for hypoxic tissue damage and neuroinflammation. Conversely, Pericyte Gs-DREADD mice will be generated to relax CNS pericytes and dilation capillaries through chemogenetic inhibition. This tool can be used to rescue capillary perfusion in disease models where abnormal pericyte contraction has been implicated. If these initial studies are successful, the R33 phase will characterize the Pericyte Gq-DREADD hypoperfusion model by performing a battery of sensorimotor and cognitive tests. Longitudinal high-field MRI for cerebral blood flow and white matter integrity will be conducted. Single cell transcriptomic analysis will be used to map transcriptomic changes resulting from acute and chronic hypoperfusion. Finally, the new mice will be bred with established genetic models of amyloid β over-expression (TgSwDi) to test the hypothesis that capillary hypoperfusion worsens amyloid β deposition and augments pathology. Pericyte Gs-DREADDs will be crossed with TgSwDi mice to determine if age-related cerebral blood flow deficits can be ameliorated. After characterization, Pericyte Gq-DREADD and Gs-DREADD mice will be independently tested by collaborating laboratories and shared through the Jackson Laboratory and MODEL-AD centers.
Terms: <2-photon><21+ years old><AD dementia><AD model><Acceleration><Acute><Address><Adult><Adult Human><Adventitial Cell><Agonist><Alleles><Allelomorphs><Alzheimer Type Dementia><Alzheimer beta-Protein><Alzheimer disease dementia><Alzheimer sclerosis><Alzheimer syndrome><Alzheimer's><Alzheimer's Amyloid beta-Protein><Alzheimer's Disease><Alzheimer's amyloid><Alzheimer's disease model><Alzheimers Dementia><Amentia><Amyloid><Amyloid Alzheimer's Dementia Amyloid Protein><Amyloid Beta-Peptide><Amyloid Protein A4><Amyloid Substance><Amyloid beta-Protein><Amyloid deposition><Amyloid β><Amyloid β-Peptide><Amyloid β-Protein><Animal Model><Animal Models and Related Studies><Autoregulation><Aβ><BBB function><Bilateral><Biological><Blood Vessels><Blood capillaries><Blood flow><Body Tissues><Breeding><CNS Nervous System><CRISPR approach><CRISPR based approach><CRISPR method><CRISPR methodology><CRISPR technique><CRISPR technology><CRISPR tools><CRISPR-CAS-9><CRISPR-based method><CRISPR-based technique><CRISPR-based technology><CRISPR-based tool><CRISPR/CAS approach><CRISPR/Cas method><CRISPR/Cas technology><CRISPR/Cas9><CRISPR/Cas9 technology><Carotid Artery Narrowing><Carotid Artery Stenosis><Carotid Stenosis><Cas nuclease technology><Cell Body><Cells><Central Nervous System><Cephalic><Cerebral vascular pericyte><Cerebrovascular Circulation><Chemicals><Chronic><Clinical><Clustered Regularly Interspaced Short Palindromic Repeats approach><Clustered Regularly Interspaced Short Palindromic Repeats method><Clustered Regularly Interspaced Short Palindromic Repeats methodology><Clustered Regularly Interspaced Short Palindromic Repeats technique><Clustered Regularly Interspaced Short Palindromic Repeats technology><Cognitive Disturbance><Cognitive Impairment><Cognitive decline><Cognitive function abnormal><Collaborations><Cranial><Cre Lox technology><Cre LoxP system><Cre lox recombination><Cre lox recombination system><Cre lox system><Cre recombinase/LoxP technology><Cre system><Crossbreeding><Customized Drugs><DNA Recombination><DREADDs><Data><Dementia><Designer Drugs><Diameter><Disturbance in cognition><Dose><Dysfunction><Engineering><Exhibits><Fibroblasts><Functional disorder><G Protein-Complex Receptor><G Protein-Coupled Receptor Genes><G-Protein-Coupled Receptors><GPCR><Genes><Genetic><Genetic Hybridization><Genetic Markers><Genetic Models><Genetic Recombination><Histology><Homeostasis><Hypoxia><Hypoxic><IRES><Image><Impaired cognition><Impairment><Internal Ribosome Entry Segment><Internal Ribosome Entry Site><Investigators><KI mice><Knock-in><Knock-in Mouse><Laboratories><Leiomyocyte><Ligands><LoxP-flanked allele><Maps><Mediating><Metabolic><Mice><Mice Mammals><Modeling><Murine><Mus><Neuraxis><O element><O2 element><Oxygen><Oxygen Deficiency><Pathology><Perfusion><Pericapillary Cell><Pericytes><Peripheral><Perivascular Cell><Phase><Physiological Homeostasis><Physiopathology><Primary Senile Degenerative Dementia><Receptor Protein><Recombination><Relaxation><Reporter><Research><Research Personnel><Researchers><Ribosome Entry Site><Rouget Cells><Severities><Smooth Muscle Cells><Smooth Muscle Myocytes><Smooth Muscle Tissue Cell><Specificity><Tamoxifen><Technology><Testing><The Jackson Laboratory><Tissues><Transgenic Model><a beta peptide><abeta><abeta deposition><adulthood><age associated><age correlated><age dependent><age linked><age related><age specific><aged mice><aged mouse><alzheimer model><amyloid beta><amyloid beta deposition><amyloid β deposition><amyloid-b protein><aβ deposition><beta amyloid fibril><biologic><blood flow in brain><blood-brain barrier function><bloodbrain barrier function><brain MR imaging><brain MRI><brain blood circulation><brain blood flow><brain capillary><brain control><brain magnetic resonance imaging><brain pericytes><brain perivascular cell><brain vascular pericyte><capillary><cardiac disease induced cognitive impairment><cerebral MR imaging><cerebral MRI><cerebral blood flow><cerebral capillary><cerebral circulation><cerebral hypoperfusion><cerebral magnetic resonance imaging><cerebral microinfarct><cerebral microinfarcts><cerebral microscopic infarct><cerebral pericyte><cerebrocirculation><cerebrovascular blood flow><cerebrovascular pericyte><cognitive assessment><cognitive dysfunction><cognitive loss><cognitive testing><constriction><designer receptors exclusively activated by designer drugs><disease model><disorder model><drinking water><elderly mice><floxed><floxed allele><gene biomarker><gene expression biomarker><gene marker><gene signature biomarker><genetic biomarker><gray matter><hypoperfusion><imaging><improved><in vivo><knockin><knockin mice><model of animal><mouse model><murine model><neural inflammation><neuroinflammation><neuroinflammatory><novel><old mice><overexpress><overexpression><pathophysiology><pre-clinical><preclinical><primary degenerative dementia><receptor><senile dementia of the Alzheimer type><soluble amyloid precursor protein><substantia alba><substantia grisea><therapeutic target><tool><transcriptomics><transgenic trait><two-photon><vascular><vascular cognitive impairment and dementia><vascular contributions to cognition/dementia><vascular contributions to cognitive impairment and dementia><white matter>