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ARS Home » Northeast Area » Beltsville, Maryland (BHNRC) » Beltsville Human Nutrition Research Center » Diet, Genomics and Immunology Laboratory » Research » Publications at this Location » Publication #349384
Title: Extensive degradation and low bioavailability of orally consumed corn miRNAs in mice

Author
item HUANG, HAIQIU - University Of Maryland
item DAVIS, CINDY - National Institutes Of Health (NIH)
item Wang, Thomas - Tom

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2018
Publication Date: 2/15/2018
Citation: Huang, H., Davis, C., Wang, T.T. 2018. Extensive degradation and low bioavailability of orally consumed corn miRNAs in mice. Nutrients. 10(2)pii: E215. https://doi.org/10.3390/nu10020215.
DOI: https://doi.org/10.3390/nu10020215

Interpretive Summary: The current study seeks to resolve the discrepancy in the literature regarding the cross-kingdom transfer of plant miRNAs into mammals using an improved miRNA processing and detection method. Two studies utilizing C57BL/6 mice were performed. In the first study, mice were fed an AIN-93M diet and gavaged with water, random dNTP or isolated corn miRNAs for two weeks (n=10 per group). In the second study, mice were fed an AIN-93M diet, or the diet supplemented with 3% fresh or autoclaved corn powder for two weeks (n=10 per group). Corn miRNA levels were analyzed in blood and tissue samples by RT-PCR following periodate oxidation and ß elimination treatments to eliminate artifacts. After removing false positive detections, there were no differences in corn miRNA levels between control and treated groups in cecal, fecal, liver and blood samples. Using an in vitro digestion system, corn miRNAs in AIN-93M diet or in the extracts were found to be extensively degraded. Less than 1% was recovered in the gastrointestinal tract after oral and gastric phases. In conclusion, no evidence of increased levels of corn miRNAs in whole blood or tissues after supplementation of corn miRNAs in the diet was observed in a mouse model. The Study provide fundamental information for basic and translational scientist on how diet-derived small RNA is processed during digestion.

Technical Abstract: The current study seeks to resolve the discrepancy in the literature regarding the cross-kingdom transfer of plant miRNAs into mammals using an improved miRNA processing and detection method. Two studies utilizing C57BL/6 mice were performed. In the first study, mice were fed an AIN-93M diet and gavaged with water, random dNTP or isolated corn miRNAs for two weeks (n=10 per group). In the second study, mice were fed an AIN-93M diet, or the diet supplemented with 3% fresh or autoclaved corn powder for two weeks (n=10 per group). Corn miRNA levels were analyzed in blood and tissue samples by RT-PCR following periodate oxidation and ß elimination treatments to eliminate artifacts. After removing false positive detections, there were no differences in corn miRNA levels between control and treated groups in cecal, fecal, liver and blood samples. Using an in vitro digestion system, corn miRNAs in AIN-93M diet or in the extracts were found to be extensively degraded. Less than 1% was recovered in the gastrointestinal tract after oral and gastric phases. In conclusion, no evidence of increased levels of corn miRNAs in whole blood or tissues after supplementation of corn miRNAs in the diet was observed in a mouse model.