Stable Isotope Labeling Kinetics (SILK) tracing of neurofilament light in stem cell‐derived neurons

Neurofilament light polypeptide (NfL) is a basic component of intermediate filaments in neurons that is released from damaged and/or degenerated neuronal axons. As such, NfL levels in CSF and serum are elevated in several neurodegenerative diseases, and have been proposed as a promising biomarker of axonal damage. However, whether NfL’s extracellular release results from passive events or active mechanisms remains largely unknown. Kinetic labeling at the step of protein translation can inform about active translation vs. passive release processes and provide protein metabolism half‐lives and rates of production and clearance.