Extracellular Vesicles

Extracellular vesicles are nano-sized (0.05–1 μm) membrane vesicles that transport molecules between tissues via the bloodstream. The bioactive cargo in EVs is enriched in microRNAs (miRNAs), small non-coding RNAs that precisely regulate the cellular transcriptome via the repression of messenger RNA (mRNA) transcripts. Once internalized by the predestined recipient cell, miRNAs alter transcriptional programming, effectively modifying the cell’s biology. Studies show that miRNA expression in EVs varies in response to environmental exposures, including air pollutant and metals exposure.

In addition to their role in circulation, EVs are abundant in human milk. They are excreted by the mammary epithelium into milk and survive digestion in the infant gut. Breastfeeding is critical for child development. However, the maternal environment has the potential to alter the contents of human milk to confer adverse effects to the child. We have shown that hundreds of EV microRNAs are detectable in human milk and are strongly linked to time since birth, maternal BMI and maternal smoking, but not parity. We have further identified sets of microRNAs are mechanistic biomarkers for prenatal methylmercury exposure and for air pollutant exposures. This work is vital in identifying the determinants of infant nutrition.

In the wet lab, we are well-versed in several techniques for EV isolation from milk, serum and plasma, including the ExoEasy kit (Qiagen), ultracentrifugation, and Size exclusion chromatography (Izon). We further quantify and characterize EVs through semiquantitative dot blots, ELISAs, and nanoparticle tracking analysis with a Viewsizer 3000. We also specialize in small RNA sequencing from EVs.

Sample Publications

Kupsco A; Prada D; Valvi D; Hu L; Skaalum Peterson M; Coull B; Grandjean P; Weihe P; Baccarelli AA. Marine pollutant exposures and human milk extracellular vesicle-microRNAs in a mother-infant cohort from the Faroe Islands. Environ Int. 2022 Jan;158:106986. PMCID: PMC8742869

Kupsco A; Prada D; Valvi D; Hu L; Skaalum Peterson M; Coull B; Grandjean P; Weihe P; Baccarelli AA. Breast milk extracellular vesicle miRNAs, pathways, and ontology in a population-based mother-infant cohort from the Faroe Islands. Sci Rep. 2021; 11: 5840. PMCID: PMC7970999

Holzhausen EA, Kupsco A, Chalifour B, Patterson WB, Schmidt KA, Mokhtari P, Baccarelli AA, Goran M, Alderete TL. Human Milk EV-miRNAs: A Novel Biomarker for Air Pollution Exposure During Pregnancy. Environmental Research: Health. 2023 Sep 1;1(3):035002. PMCID: PMC10486183

Holzhausen EA, Kupsco A, Chalifour B, Patterson WB, Schmidt KA, Mokhtari P, Baccarelli AA, Goran M, Alderete TL. Influence of technical and maternal-infant factors on the measurement and expression of extracellular miRNA in human milk. Frontiers in Immunology. 2023;14:1151870. PMCID: PMC10363855