Translational biomarkers of hypoxic brain injury uncovered in CSF secreting human choroid plexus organoids.

The choroid plexus-cerebrospinal fluid (ChP-CSF) interface regulates a microenvironment supporting neural stem cell growth, strongly affected by hypoxia through ChP function. From human induced pluripotent stem cells (hiPSCs), here we established and validated in vitro ChP organoid secreting CSF-like fluid (iCSF) and exposed them to low oxygen atmosphere for 24 h. Transcriptomic indicated major data on morphological and functional alterations in the ChP cells and shotgun proteomics revealed significant changes in proteins involved in energy metabolism and mitochondrial function. We found that H2AZ and ITM2B, involved in neurogenesis and neurite growth, were the key proteins downregulated in hypoxic iCSF and ChP organoids, respectively. Positive correlation analysis between hypoxia-induced mRNA expression of the neuronal progenitor biomarkers SOX2 and PAX6. Mature neuron MAP2 and H2AZ also confirmed impairment of neurogenesis. The results from this study suggest that ChP-CSF interface opens new opportunities to characterize hypoxic brain pathophysiology and discover novel biomarkers.