Serum Proteoglycan Alterations Associated with Cardiovascular Risk in Pb-Battery Recycling Workers Using Exploratory Proteomics and Independent ELISA Validation.
Exploratory serum proteomics of Pb-battery recycling workers identified altered proteins involved in lipid transport and extracellular matrix organization, and the independent validation of lumican (LUM) and proteoglycan-4 (PRG4) suggests they may be candidate biomarkers associated with Pb-related cardiovascular alterations.
Key Findings
Results
High-resolution mass spectrometry identified 257 serum proteins in pooled samples from Pb-battery recycling workers and unexposed controls.
Discovery cohort: Pb-BRW (n = 78) and age-matched unexposed controls (n = 65) from three industries in Karnataka, India.
Serum samples (n = 10) pooled from each group were analyzed using quantitative discovery HRMS.
Raw files were processed in Proteome Discoverer against the UniProt Homo sapiens reviewed database, then analyzed in Perseus with log2 transformation and imputation.
Data are available via ProteomeXchange (PXD082567).
Results
Exploratory proteomic profiling identified 26 candidate proteins with nominal p < 0.05 between Pb-BRW and controls.
Candidate selection used exploratory filtering criteria of nominal p < 0.05 and |log2FC| ≥ 1.2.
Results were visualized with a volcano plot and heatmap.
The p-values were nominal, which the authors describe as exploratory filtering.
Results
Eight candidate proteins met both exploratory filtering criteria, five with higher and three with lower abundance in Pb-BRW.
Both criteria were nominal p < 0.05 and |log2FC| ≥ 1.2.
Five proteins were more abundant and three less abundant in Pb-BRW relative to controls.
Results
Functional enrichment analysis suggested the differentially abundant proteins are associated with cardiovascular-related processes, lipid transport and extracellular matrix organization.
Gene ontology was used for functional enrichment analysis.
The abstract concludes that alterations were found in proteins involved in lipid transport and extracellular matrix organization in Pb-BRW.
Results
Lumican (LUM) and Proteoglycan-4 (PRG4) were selected for ELISA validation and the authors report their independent validation in a separate sample set.
Selection was based on abundance patterns and biological relevance to extracellular matrix organisation and vascular homeostasis.
The validation cohort comprised independent serum samples from Pb-BRW (n = 68) and controls (n = 55).
Blood Pb levels were measured by inductively coupled plasma-optical emission spectroscopy.
The abstract does not give the ELISA effect sizes or p-values.
Conclusions
The authors conclude LUM and PRG4 are potential candidate biomarkers associated with Pb-related cardiovascular alterations.
The framing is exploratory, with proteomic findings described as candidate associations.
Validation was by ELISA in an independent set of serum samples.
What This Means
This study looked at proteins in the blood of workers who recycle lead batteries in India, comparing them with similar people who were not exposed to lead. Using a sensitive mass spectrometry method on pooled blood samples, the researchers found 257 proteins. Twenty-six differed between the groups at a preliminary statistical level, and eight showed larger differences, with five higher and three lower in the lead-exposed workers.
The proteins that differed were linked to how fats are transported in the blood and how the structural framework around cells (the extracellular matrix) is organized, processes related to heart and blood vessel health. Two proteins, lumican and proteoglycan-4, were chosen for follow-up testing by ELISA in a separate group of 68 workers and 55 controls, and the authors report that this supported the initial findings.
This research suggests that these two proteins might serve as markers of cardiovascular changes related to lead exposure. However, the initial discovery used pooled samples and preliminary statistical thresholds, so the findings are exploratory. Larger studies are needed to confirm whether these proteins can reliably flag cardiovascular risk in lead-exposed workers.