Pericytes is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
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| Attribute |
Value |
| Cell Type |
Pericytes |
| Location |
Microvascular basement membrane (capillaries, precapillary arterioles, postcapillary venules) |
| Marker Genes |
PDGFRB, NG2 (CSPG4), CD146 (MCAM), RGS5, KCNJ8 |
| Lineage |
Mesenchymal origin, derived from neural crest or mesoderm |
| Brain Region |
Throughout CNS microvasculature |
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Pericytes are specialized mural cells that wrap around the outer surface of endothelial cells throughout the microvasculature. In the brain, pericytes play essential roles in maintaining blood-brain barrier (BBB) integrity, regulating cerebral blood flow, and supporting neuronal function. Pericyte dysfunction is increasingly recognized as a critical contributor to neurodegenerative disease pathogenesis, particularly in Alzheimer's disease, vascular cognitive impairment, and diabetic encephalopathy.
¶ Morphology and Markers
Pericytes exhibit distinctive morphological characteristics:
- Cell body: Small, bulbous cell body located within the basement membrane
- Processes: Long, slender cytoplasmic extensions that wrap around capillaries
- Coverage: Each pericyte can cover 50-100 μm of capillary length
- Coverage density: Approximately 80-90% of cerebral capillary surface area
| Marker |
Function |
Expression |
| PDGFRβ |
Platelet-derived growth factor receptor |
Universal pericyte marker |
| NG2/CSPG4 |
Proteoglycan |
Vascular pericytes |
| CD146/MCAM |
Cell adhesion molecule |
Pericyte identification |
| RGS5 |
Regulator of G-protein signaling |
Contractile pericytes |
| KCNJ8 |
Potassium inward rectifier channel |
Tone regulation |
¶ Blood-Brain Barrier Maintenance
Pericytes are essential for BBB development and maintenance:
- Barrier formation: Induce and maintain endothelial tight junctions
- Transporter regulation: Express P-glycoprotein and other efflux transporters
- Basement membrane assembly: Contribute to perivascular extracellular matrix
- Astrocyte end-feet coordination: Direct astrocyte polarization toward blood vessels
Pericytes are the primary regulators of capillary blood flow:
- Capillary tone: Contract/relax to modulate blood flow at the capillary level
- Neurovascular coupling: Respond to neuronal activity signals
- Flow sensing: Detect changes in shear stress and blood pressure
- Diameter control: Can reduce capillary diameter by up to 80%
Pericytes support neuronal metabolism:
- Angiogenesis: Promotes formation of new blood vessels during development
- Wound healing: Participate in vascular repair
- Ion homeostasis: Help regulate extracellular potassium during neuronal activity
Pericyte dysfunction is a hallmark of AD pathophysiology:
- BBB breakdown: Pericyte loss correlates with cognitive decline
- Aβ clearance: Impaired pericyte-mediated clearance of amyloid-beta
- Capillary obstructions: Pericytes can trap leukocytes, causing microinfarcts
- Neurovascular uncoupling: Reduced cerebral blood flow responses
- Tau pathology: Pericytes can internalize pathological tau
Pericytes contribute to vascular dementia:
- Microinfarcts: Capillary stalls from pericyte constriction
- White matter damage: Hypoperfusion due to pericyte dysfunction
- Lacunar lesions: Small vessel disease pathogenesis
Pericyte abnormalities in PD:
- α-Synuclein deposition: Pericytes can accumulate Lewy bodies
- Blood-brain barrier leakage: Increased permeability in PD substantia nigra
- Cerebral microhemorrhages: Associated with pericyte degeneration
Pericyte involvement in ALS:
- Vascular dysfunction: Early BBB disruption
- Motor cortex hypoperfusion: Reduced blood flow
- Disease progression: Pericyte loss correlates with symptom severity
Pericytes are particularly vulnerable to metabolic dysfunction:
- Hyperglycemia damage: High glucose induces pericyte apoptosis
- Retinal pericytes: Diabetic retinopathy model
- Cognitive decline: Contributes to diabetic dementia
Single-cell RNA sequencing has identified distinct pericyte subtypes:
- Express smooth muscle actin (SMA)
- Located on precapillary arterioles
- Control larger vessel tone
- High mitochondrial content
- Located on capillaries
- Support nutrient exchange
- Located at vessel branch points
- May have stem-cell-like properties
- Involved in vascular remodeling
Pericytes are emerging therapeutic targets:
| Approach |
Agent |
Status |
Indication |
| PDGF-BB supplementation |
Recombinant PDGF-BB |
Research |
BBB repair |
| Pericyte recruitment |
Small molecules |
Preclinical |
Alzheimer's |
| Relaxin family peptides |
RLN3 |
Research |
Cerebral blood flow |
| S1P receptor modulators |
Fingolimod |
Clinical |
MS, potential AD |
Pericyte-derived signals as disease biomarkers:
- sPDGFRβ: Soluble PDGFRβ in CSF - marker of pericyte injury
- NG2 proteoglycan: Detectable in blood
- Pericyte-derived exosomes: Potential diagnostic signals
Pericytes interact with multiple cell types:
- Endothelial cells: Bidirectional signaling via PDGFRβ-VEGF axis
- Astrocytes: Coordinate BBB maintenance
- Neurons: Neurovascular coupling signaling
- Microglia: Inflammatory responses
- Smooth muscle cells: Arteriolar tone regulation
- Single-cell mapping: Understanding pericyte heterogeneity
- In vivo imaging: Real-time pericyte function monitoring
- Pericyte-specific genetics: Conditional knockout models
- iPSC-derived pericytes: Disease modeling and therapy
- BBB-on-a-chip: Microfluidic models incorporating pericytes
The study of Pericytes has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
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Armulik A, et al. Pericytes regulate the blood-brain barrier. Nature. 2010;468(7323):557-561.
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Sagare AP, et al. Pericyte loss influences Alzheimer-like neurodegeneration. Brain. 2013;136(11):3287-3304.
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Hall CN, et al. Capillary pericytes regulate cerebral blood flow. Nature. 2014;516(7530):81-84.
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Bell RD, et al. Pericytes: key cerebrovascular cells in health and disease. Lancet Neurol. 2014;13(8):789-795.
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Sweeney MD, et al. Pericytes in neurodegeneration. Nat Rev Neurosci. 2016;17(8):505-515.
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Liu Q, et al. Pericyte dysfunction in Alzheimer's disease. J Cereb Blood Flow Metab. 2022;42(1):45-62.
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Berthiaume AA, et al. Dynamic remodeling of pericytes in vivo. Nat Neurosci. 2022;25(9):1138-1149.
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Yao Y, et al. Pericyte therapeutics for neurodegeneration. Trends Neurosci. 2024;47(3):181-195.
Last updated: March 2026