Isolation of Exosome-Like Nanoparticles and Analysis of MicroRNAs Derived from Coconut Water Based on Small RNA High-Throughput Sequencing

Abstract

In this study, the presence of microRNAs in coconut water was identified by real-time polymerase chain reaction (PCR) based on the results of high-throughput small RNA sequencing. In addition, the differences in microRNA content between immature and mature coconut water were compared. A total of 47 known microRNAs belonging to 25 families and 14 new microRNAs were identified in coconut endosperm. Through analysis using a target gene prediction software, potential microRNA target genes were identified in the human genome. Real-time PCR showed that the level of most microRNAs was higher in mature coconut water than in immature coconut water. Then, exosome-like nanoparticles were isolated from coconut water. After ultracentrifugation, some particle structures were seen in coconut water samples using 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate fluorescence staining. Subsequent scanning electron microscopy observation and dynamic light scattering analysis also revealed some exosome-like nanoparticles in coconut water, and the mean diameters of the particles detected by the two methods were 13.16 and 59.72 nm, respectively. In conclusion, there are extracellular microRNAs in coconut water, and their levels are higher in mature coconut water than in immature coconut water. Some exosome-like nanoparticles were isolated from coconut water, and the diameter of these particles was smaller than that of animal-derived exosomes.

Protective Role of Shiitake Mushroom-Derived Exosome-Like Nanoparticles in D-Galactosamine and Lipopolysaccharide-Induced Acute Liver Injury in Mice

“…Sizes of ELNs from seven edible mushrooms ranged from 100 nm to 140 nm in diameters ( Figure 1A). Their sizes were comparable to those of dietary ELNs extracted from edible plants [21,33,45]. Mushroom-derived ELNs contained RNAs, proteins, and lipids ( Figure 1D-F) and, therefore, were similar in composition to other dietary ELNs [20,21,30].…”

“…Recently, dietary ELNs have been extracted from fruits (such as grapes [21], grapefruit [17,19], apples [33], and coconut water [45]); vegetables (such as carrots [21] and broccoli [31]); and spices (such as ginger [19,20,30] and turmeric [20]). However, it was not known whether edible mushrooms contained any ELNs.…”

Effect of microvesicles from Moringa oleifera containing miRNA on proliferation and apoptosis in tumor cell lines

“…These MVs may mediate plant-animal communication, having a role in cross-kingdom regulation processes, by delivering plant sRNAs and miRNAs to mammalian systems 7,[10][11][12][13] .…”

Plant MicroRNAs in Cross-Kingdom Regulation of Gene Expression

“…Generally, this discovery of so-called cross-kingdom regulation of gene expression indicates a potentially therapeutic role for plant miRNAs, which may be of value in medicine; in the near future, many human diseases may be treatable by the consumption of specific plant miRNAs through food. Such findings have been confirmed or partially confirmed by other laboratories or in other experimental settings [ 24 , 25 , 26 , 27 ], but have been strongly questioned by other authors in light of a lack of repeatability [ 16 , 28 , 29 , 30 ]. Many of these very recent reports, from each side of the controversy, have been reviewed and discussed in the papers by Perge et al [ 31 ] and Lukasik et al [ 32 ].…”

“…These vesicles have reported to protect miRNAs from degradation by RNases [ 62 , 63 ]. In addition to animal body fluids, exosome-like nanoparticles containing proteins, lipids, and RNAs have also been found in many plant sources, such as ginger, carrot, watermelon, grapes, olives, melon seeds, and coconut [ 25 , 64 , 65 , 66 , 67 ]. Published studies have suggested that exosome-like nanoparticles derived from plants may mediate interspecies communication and induce the expression of certain human genes [ 64 ].…”