RPS29 as a potential early diagnostic biomarker for necrotizing enterocolitis: validation from transcriptomic and proteomic cohorts

<h4>Background</h4>Necrotizing enterocolitis (NEC) is a life-threatening gastrointestinal disorder in neonates, and its early diagnosis remains challenging. RPS29, a ribosomal protein associated with cellular stress and inflammation, was identified as significantly differentially expressed in the discovery proteomic screening. This study aimed to identify RPS29 as a potential biomarker for the early diagnosis of NEC.<h4>Methods</h4>In a prospective cohort, plasma samples were analyzed using Astral proteomics (controls, n=12; NEC stage I, n=12; NEC stage II, n=13; NEC stage III, n=12). Transcriptomic profiling was performed to assess mRNA expression in intestinal tissues from controls (n=5) and NEC patients (n=5). Plasma protein levels were further quantified by enzyme-linked immunosorbent assay (ELISA), while their expression in intestinal tissues from NEC infants and NEC mouse models was validated by immunofluorescence and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The diagnostic performance of plasma protein was evaluated using receiver operating characteristic (ROC) curves and compared with routine hematological parameters.<h4>Results</h4>RPS29 showed significantly decreased levels in the plasma of infants with NEC in the proteomic dataset, particularly in Bell stage I NEC. Plasma ELISA of RPS29 protein also revealed a significant decrease in RPS29 levels in Bell stage I NEC. RPS29 protein showed favorable diagnostic performance, with areas under the curve (AUCs) of 0.9679 and 0.9306 at stages II and III, and as high as 0.9861 at stage I. Intestine transcriptomics revealed a significant decrease of RPS29 in NEC patients, which was consistent with downregulation of RPS29 protein and mRNA expression validated in both NEC patients and mouse models.<h4>Conclusions</h4>Plasma RPS29 protein exhibits potential diagnostic accuracy for early-stage NEC and represents a promising biomarker for its early detection.