The atypical genesis and bioavailability of the plant-based small RNA MIR2911: Bulking up while breaking down.
The uptake of dietary plant small RNAs (sRNAs) in consumers remains controversial, which is mainly due to low dietary content in combination with poor fractional absorption. MIR2911, among all the plant sRNAs including microRNAs, has been shown to be one of the most robustly absorbed sRNAs. Here we analyze the unusual abundance and unique genesis of MIR2911 during vegetable processing.



Using qRT-PCR, the abundance of MIR2911 increased dramatically in macerated tissues while other microRNAs degraded. The accumulation of MIR2911 correlated with the degradation of the rRNAs, consistent with MIR2911 being derived from the 26S rRNA. Bioinformatic analysis predicts a microRNA-like precursor structure for MIR2911; however, no reciprocal increase in the putative star-strand was noted, and using an Arabidopsis mutation deficient in miRNA processing the accumulation of MIR2911 appeared Dicer independent. MIR2911 was incorporated into the mammalian RNA-induced silencing complex as demonstrated in HEK293T cells, where transfected synthetic MIR2911 modestly suppressed the activity of a cognate luciferase reporter.



The genesis and amplification of MIR2911 post-harvest is atypical, as traditional plant bioactives are less plentiful as vegetables lose freshness. These findings offer an explanation to the disparity in serum detection between MIR2911 and canonical plant-based miRNAs.
USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
Jian
J
Yang
Department of Molecular Biology and Biophysics, Baylor College of Medicine, Houston, TX, USA.
Natee
N
Kongchan
USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
Cecilia
C
Primo Planta
Department of Molecular Biology and Biophysics, Baylor College of Medicine, Houston, TX, USA.
Joel R
JR
Neilson
USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.|Vegetable and Fruit Improvement Center, Texas A&M University, College Station, TX, USA.
Kendal D
KD
Hirschi
D001682:Biological Availability; D001937:Brassica / Q000235:genetics; D005511:Food Handling; D057809:HEK293 Cells; D006801:Humans; D035683:MicroRNAs / Q000032:analysis / Q000502:physiology*; D018749:RNA, Plant / Q000032:analysis / Q000502:physiology*
D035683:MicroRNAs; D018749:RNA, Plant
Absorption; Bioavailability; Food consumption marker; MicroRNA; Vegetables