Proteome analysis of amniotic fluid from fetuses with myelomeningocele

ABSTRACT: Background – Although many studies have been conducted to develop fetal therapy for myelomeningoceles (MMC), pathophysiology of this malformation remains poorly understood. The purpose of our study was to compare amniotic fluid (AF) of fetuses with MMC and healthy fetuses using biochemical and proteomic analysis to explore the prenatal pathophysiology of MMC. Methods – The biochemical analysis of 61 AF samples from MMC singletons fetuses was compared to those of 45 AF samples from healthy singletons fetuses. This analysis included the dosage of urea, uric acid, creatinine, amylase, total proteins, and the assay of the following enzyme activities: gamma-glutamyl transpeptidase, aminopeptidase M, alkaline phosphatase isoenzymes. A cohort of 36 AF samples from singletons fetuses was analysed using data independent analysis MS. The strongest candidates were validates by western blot. AF samples from five MMC fetuses from dichorionic twin pregnancies and those of their healthy co-twins were also analysed using using high-resolution mass spectrometry. Results – Biochemical analysis showed an increase in enzymes activities of aminopeptidase M (AMP), alkaline phosphatase isoenzymes (tALP) and intestinal alkaline phosphatase isoenzyme (iALP) in the MMC group, compared to the control group. The biochemical profile comparison of the two groups revealed an anal incontinence profile in 37% of the MMC cases and a normal profile in all the controls (p<0.0001). No significant differences were found in creatinine, uric acid, urea, and amylase levels between both groups. AF proteome comparison of the singleton cohort of showed an increase in 37 proteins and a decrease in 8 proteins in MMC AF samples compared to control AF samples. It also highlighted an evolution in some proteins abundance according the gestation week. We therefore analyzed AF samples for twin pregnancy, which largely confirmed and refined the candidates previously found. Among the increased proteins, eleven (CHL1, ALPLP1, SEZ6, SEZ6L, APP…..) correspond to substrates for the BACE1 secretase, and three were validated by western blot. APOB was also found elevated in all MMC AF and was validated by ELISA. The elevated proteins found in the AF strongly correlated with the neonatal CSF previously reported, rendering the AF analysis a preview if the neonatal CSF in the second trimester of gestation. Conclusion – Our study is the first to suggest an association between MMC and secretase BACE1 with an overexpression or a functional dysregulation of BACE1 in fetuses with MMC. The study also suggests that amniotic fluid (AF) analysis is a preview of the cerebrospinal fluid (CSF) from the newborn, and that it could be used to help predict the prognosis of the fetus.

INSTRUMENT(S):

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Amniotic Fluid

SUBMITTER: Chiara guerrera  

LAB HEAD: Ida Chiara Guerrera

PROVIDER: PXD047861 | Pride | 2026-01-21

REPOSITORIES: Pride