Evidence of Cross-Kingdom Gene Regulation by Plant MicroRNAs and Possible Reasons for Inconsistencies

The debate on whether cross-kingdom gene regulation by orally acquired plant miRNAs is possible has been ongoing for nearly 10 years without a conclusive answer. In this study, we categorized plant miRNAs into different groups, namely, extracellular vesicle (EV)-borne plant miRNAs, extracted plant miRNAs, herbal decoction-borne plant miRNAs, synthetic plant miRNA mimics, and plant tissue/juice-borne plant miRNAs. This categorization aimed to simplify the analysis and address the question more specifically. Our evidence suggests that EV-borne plant miRNAs, extracted plant miRNAs, herbal decoction-borne plant miRNAs, and synthetic plant miRNA mimics consistently facilitate cross-kingdom gene regulation. However, the results regarding the cross-kingdom gene regulation by plant tissue- and juice-borne plant miRNAs are inconclusive. This inconsistency may be due to variations in study methods, a low absorption rate of miRNAs and the selective absorption of plant miRNAs in the gastrointestinal tract. Overall, it is deduced that cross-kingdom gene regulation by orally acquired plant miRNAs can occur under certain circumstances, depending on factors such as the types of plant miRNAs, the delivery mechanism, and their concentrations in the plant.

The knowns and unknowns of helminth-host miRNA cross-kingdom communication

MicroRNAs (miRNAs) are small noncoding RNAs that oversee gene modulation. They are integral to cellular functions and can migrate between species, leading to cross-kingdom gene suppression. Recent breakthroughs in helminth genome studies have sparked curiosity about helminth RNA regulators and their ability to regulate genes across species. Growing data indicate that helminth miRNAs have a significant impact on the host's immune system. Specific miRNAs from helminth parasites can merge with the host's miRNA system, implying that parasites could exploit their host's regulatory machinery and function. This review highlights the role of cross-kingdom helminth-derived miRNAs in the interplay between host and parasite, exploring potential routes for their uptake, processing, and consequences in host interaction.

Plant-derived cross-kingdom gene regulation benefits human health

Cross-kingdom gene regulation widely occurs in nature through small (s)RNAs or protein-encoding genes. Examples of plant-derived miRNAs that are advantageous for human health have recently been reported. Mining plant-specialized gene resources for similar cross-kingdom gene communications may lead to the identification of further plant-derived therapeutic agents that can improve human health globally.

Plant-Derived Nanovesicles: A Novel Form of Nanomedicine

The nanovesicles extracted from the plant and herbal decoctions are identified as a new class of nanomedicine. They are involved in interspecies chemical communication across the plant and animal kingdoms and display a therapeutic potential against a variety of diseases. Herein, we review the recent progress made in the medical applications of plant-derived nanovesicles in the aspects of anti-inflammation, anti-cancer, tissue regeneration, and modulating commensal microbiota. We further summarize the cellular and molecular mechanisms underlying the physiological functions of plant-derived nanovesicles. Overall, plant-derived nanovesicles provide an alternative to conventional synthetic drugs and present exciting opportunities for future research on disease therapy.