Urinary protein expression patterns in children with sleep-disordered breathing: preliminary findings
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Jyoti Krishna1, Zahoor A Shah, Michael Merchant
1Division of Pediatric Sleep Medicine and Kosair Children's Hospital Research Institute, Department of Pediatrics, University of Louisville School of Medicine, Louisville, KY 40202, USA.
Insights
Urinary gelsolin and perlecan levels may indicate obstructive sleep apnea (OSA) in children. This study identified these proteins in urine, suggesting potential biomarkers for OSA diagnosis and its effects on kidney function.
Area of Science:
- Pediatric Nephrology
- Sleep Medicine
- Proteomics
Background:
- Obstructive sleep apnea (OSA) affects millions, with diagnosis via polysomnography being burdensome.
- OSA-induced inflammation can impact kidney function and protein expression.
- Identifying non-invasive biomarkers for OSA is crucial.
Purpose of the Study:
- To analyze urinary proteins in children to identify potential biomarkers associated with OSA.
- To investigate whether differential protein expression in urine correlates with the presence of OSA.
Main Methods:
- Collected first-morning urine samples from 11 children with OSA and 11 controls (ages 3-14).
- Performed proteomic analysis on urine samples to map protein expression.
- Selected five protein spots with significant intensity differences for further analysis.
Main Results:
- Identified four proteins using mass spectrometry: gelsolin, perlecan, albumin, and immunoglobulin.
- Gelsolin and perlecan showed significant intensity differences between OSA and control groups (P<0.05).
Conclusions:
- Elevated urinary gelsolin and perlecan in children with OSA suggest potential roles in OSA-related kidney changes.
- These proteins may be affected by hypoxia-induced alterations in protein permeability or catabolism.
- Urinary gelsolin and perlecan show promise as potential non-invasive biomarkers for pediatric OSA.
Background:
Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing, with almost 15 million Americans affected and many more at risk. Current diagnostic approach to OSA requires polysomnography, which is laborious, onerous, and time-consuming. There is ample evidence that inflammatory responses to the perturbations associated with OSA trigger a variety of genes and signaling cascades that ultimately lead to end-organ injury and changes in kidney function and protein expression. The aim of this study was therefore to analyze proteins in human urine and assess whether differential expression of particular proteins is associated with the presence of OSA.
Methods:
Eleven OSA and 11 control children between the ages of three and 14 (males=17; females=5) underwent overnight sleep studies followed by a first-morning urine sample. Proteomic analysis of urine samples yielded a unique map of proteins, of which, five spots were selected for further analysis due to their significant intensity differences between OSA and control groups.
Results:
Mass spectrometry followed by peptide mass fingerprinting conclusively identified four of the five spots as gelsolin, perlecan (a heparan sulfate proteoglycan), albumin, and immunoglobulin (P<0.05 and protein scores>67).
Conclusions:
Overall, increased expression of gelsolin and perlecan in the urinary proteome of children with OSA suggests that the episodic hypoxia associated with OSA may lead to changes in protein permeability or alternatively to increased catabolism of these proteins and their excretion in urine.
