Circulating Exosomal MicroRNA Profiles Associated with Heavy Metal Exposure and Short Stature in Children

Area of Science:

• Environmental Health
• Pediatric Endocrinology
• Molecular Biology

Background:

• Childhood growth impairment, including idiopathic short stature (ISS) and growth hormone deficiency (GHD), has potential links to environmental factors.
• The specific biological mechanisms connecting heavy metal exposure to growth impairment remain largely unelucidated.

Purpose of the Study:

• To investigate the association between exposure to heavy metals (Pb, As, Hg) and growth impairment (ISS, GHD) in children.
• To identify circulating exosomal microRNAs (miRNAs) associated with heavy metal exposure and growth impairment.

Main Methods:

• Measured blood and urine concentrations of nine metals in 36 children (24 cases, 12 controls).
• Profiled serum exosomal miRNAs using sequencing.
• Analyzed associations between metal levels, ISS, and GHD, and identified differentially expressed miRNAs.

Main Results:

• Elevated exposure to lead (Pb), arsenic (As), and mercury (Hg) was associated with increased prevalence of ISS and GHD.
• High blood Pb correlated with ISS (p=0.01), and high urinary As with short stature (p=0.03).
• Downregulated hsa-miR-4488 and upregulated hsa-miR-133a-3p/hsa-miR-4516 were observed in relation to heavy metal exposure and growth impairment.

Conclusions:

• Pb, As, and Hg exposure are linked to impaired childhood growth.
• Dysregulated miRNAs suggest mechanisms involving growth hormone (GH)-insulin-like growth factor-1 (IGF-1) signaling and endochondral ossification.
• These findings highlight potential molecular pathways affected by heavy metal toxicity in pediatric growth disorders.