| Choroid Plexus Epithelial Cells | |
|---|---|
| Allen Atlas ID | CS202210140_3725 |
| Lineage | Glial > Choroid plexus > Epithelial |
| Markers | TTR, AQP1, SLC13A5, KCNQ1, SLC4A10 |
| Brain Regions | Choroid plexus (lateral, third, fourth ventricles) |
| Disease Vulnerability | Hydrocephalus, [Alzheimer's Disease](/diseases/alzheimers-disease) |
| Cell Ontology ID | [CL:0000706](https://purl.obolibrary.org/obo/CL_0000706), [CL:4301608](https://purl.obolibrary.org/obo/CL_4301608) |
Choroid plexus epithelial cells (CPECs) are a specialized population of cuboidal epithelial cells that form the blood–cerebrospinal fluid barrier (BCSFB) and are responsible for the production of approximately 500 mL of cerebrospinal fluid (CSF) per day in the adult human brain [1]. Located in the choroid plexus of the lateral, third, and fourth ventricles, CPECs perform essential functions including CSF secretion, nutrient transport, waste clearance, immune surveillance, and secretion of neurotrophic factors. In Alzheimer's disease and other neurodegenerative conditions, CPEC dysfunction contributes to impaired CSF turnover, reduced clearance of amyloid-beta and tau, and disrupted brain homeostasis [2]. Understanding CPEC biology is critical for developing CSF-based biomarkers and therapeutic strategies targeting brain waste clearance.
| Taxonomy | ID | Name / Label |
|---|---|---|
| Cell Ontology (CL) | CL:0000706 | choroid plexus epithelial cell |
| Database | ID | Name | Confidence |
|---|---|---|---|
| Cell Ontology | CL:0000706 | choroid plexus epithelial cell | Exact |
| Cell Ontology | CL:4301608 | choroid plexus epithelial cell (Mmus) | Exact |
The choroid plexus is a highly vascularized, villous tissue suspended in the ventricular lumen. Each villus consists of:
CPECs have a distinctive polarized morphology:
Key molecular markers for CPEC identification:
| Gene | Protein | Function |
|---|---|---|
| TTR | Transthyretin | Thyroxine/retinol transport into CSF |
| AQP1 | Aquaporin-1 | Water channel, apical — drives CSF flow |
| SLC13A5 | NaCT | Citrate transporter |
| KCNQ1 | Kv7.1 | Potassium channel, apical secretion |
| SLC4A10 | NBCn2 | Sodium bicarbonate cotransporter |
| CLIC6 | Chloride IC 6 | Chloride transport |
| KL | Klotho | Anti-aging factor, secreted into CSF |
CSF is produced by a two-step process:
The secretory machinery involves coordinated ion transport:
Beyond CSF, CPECs secrete a remarkable array of bioactive molecules:
The BCSFB formed by CPECs differs fundamentally from the blood-brain barrier:
| Feature | BCSFB (Choroid Plexus) | BBB (Brain Endothelium) |
|---|---|---|
| Barrier cell | Epithelial (CPEC) | Endothelial |
| Capillaries | Fenestrated (leaky) | Continuous (tight) |
| Tight junctions | Claudin-1, -2, -3 | Claudin-5 |
| Permeability | Moderate | Very low |
| Transport direction | Blood → CSF | Blood → Brain parenchyma |
| Surface area | ~200 cm² | ~20 m² |
CPECs serve as immune gatekeepers of the CNS:
CPECs undergo significant changes in AD that compound disease pathology:
CPEC dysfunction is central to both communicating and non-communicating hydrocephalus:
Age-related CPEC changes are among the most consistent findings in the aging brain:
In multiple sclerosis:
CPECs influence the composition of CSF used for diagnostic biomarkers:
Enhancing CSF turnover: pharmacological agents that increase CPEC secretory function could improve brain waste clearance
Choroid plexus-targeted drug delivery: CPECs can be targeted for intrathecal drug delivery via their unique receptor expression
TTR stabilizers: tafamidis and diflunisal stabilize TTR tetramers, potentially enhancing Aβ sequestration in CSF
Klotho supplementation: recombinant Klotho administration into CSF enhances cognition in aged mice
AQP1 modulation: aquaporin modulators could restore CSF production in aging and NPH [11]
CSF Biomarkers
Klotho
Glymphatic System
Normal Pressure Hydrocephalus
Lun MP et al. Development and functions of the choroid plexus–CSF system (2015). 2015. ↩︎
Balusu S et al. Non-junctional claudin-2 controls choroid plexus CSF secretion (2022). 2022. ↩︎
Wolburg H & Paulus W, Choroid plexus: biology and pathology (2010). 2010. ↩︎
Damkier HH et al. Cerebrospinal fluid secretion by the choroid plexus (2013). 2013. ↩︎
Spuch C & Bhatt DH, Growth factors and the choroid plexus (2012). 2012. ↩︎
Schwartz M & Baruch K, The resolution of neuroinflammation: leukocyte recruitment via the choroid plexus (2014). 2014. ↩︎
Serot JM et al. Choroid plexus, aging of the brain, and Alzheimer's disease (2003). 2003. ↩︎
Johanson CE et al. Choroid plexus dysfunction in hydrocephalus and aging (2008). 2008. ↩︎
Emerich DF et al. The choroid plexus: function, pathology, and therapeutic potential (2005). 2005. ↩︎
Reboldi A et al. C-C chemokine receptor 6-regulated entry of TH-17 cells into the CNS through the choroid plexus (2009). 2009. ↩︎
Xu R & Bhatt DH, Choroid plexus as a therapeutic target for neurodegeneration (2020). 2020. ↩︎