Ultrahigh-Power Sonicator Lysis Enables Deep Proteomic Profiling of Hair Shafts for Fetal Growth Restriction Biomarker Discovery

The
hair shaft provides a noninvasive, easily accessible specimen
with exceptional molecular stability, retaining metabolic signatures
from fetal development. However, its dense keratinization impedes
efficient protein extraction, thereby restricting the proteomic depth
and clinical applicability. To surmount this barrier, we designed
an ultrahigh-power sonicator (UHPS) that disrupts keratin networks,
boosting the protein yield by more than 1.8-fold. We coupled UHPS
with the Deep Efficient Peptide Sequencing and Quantification (DEEP
SEQ) mass spectrometry platform for the in-depth proteomic profiling
of hair shafts. This integrated workflow quantified 3,925 proteins
from just 1 mg of hair shaft sample. In fetal growth restriction (FGR)
cases versus healthy controls (HCs), we identified 239 differentially
expressed proteins (DEPs). Candidate biomarkers from this panel were
validated using parallel reaction monitoring (PRM) and an enzyme-linked
immunosorbent assay (ELISA) in independent cohorts. Their expression
levels showed strong correlations with FGR clinical indicators. The
UHPS-DEEP SEQ pipeline marks a significant advancement in hair shaft
proteomics, enabling noninvasive biomarker identification and offering
significant potential for perinatal diagnostics.