Human CNS barrier-forming organoids with cerebrospinal fluid production

TLDR

Cerebrospinal fluid supplies nutrients, signals, and removes toxins from the brain, and is produced by the choroid plexus, a protective epithelial barrier that blocks toxic molecules and drugs from entering the CNS. The authors aim to create human choroid plexus organoids that form a selective barrier and secrete CSF‑like fluid within self‑contained compartments. They establish these organoids by culturing human cells to generate a choroid plexus‑like epithelium that produces CSF‑like fluid and exhibits selective permeability. The organoids exhibit in vivo‑like small‑molecule selectivity, predict CNS permeability of new compounds, and their transcriptomic and proteomic signatures closely match native ChP, uncovering novel CSF‑producing epithelial subtypes.

Abstract

Cerebrospinal fluid (CSF) is a vital liquid, providing nutrients and signaling molecules and clearing out toxic by-products from the brain. The CSF is produced by the choroid plexus (ChP), a protective epithelial barrier that also prevents free entry of toxic molecules or drugs from the blood. Here, we establish human ChP organoids with a selective barrier and CSF-like fluid secretion in self-contained compartments. We show that this in vitro barrier exhibits the same selectivity to small molecules as the ChP in vivo and that ChP-CSF organoids can predict central nervous system (CNS) permeability of new compounds. The transcriptomic and proteomic signatures of ChP-CSF organoids reveal a high degree of similarity to the ChP in vivo. Finally, the intersection of single-cell transcriptomics and proteomic analysis uncovers key human CSF components produced by previously unidentified specialized epithelial subtypes.