High-throughput sequencing reveals biofluid exosomal miRNAs associated with immunity in pigs

Abstract

Large numbers of miRNAs are found in biofluid exosomes. We isolated~50-200 nm diameter exosomes from four types of porcine biofluid (urine, plasma, semen, and bile) using serial centrifugation and ultracentrifugation procedures. A total of 42.15 M raw data were generated from four small RNA libraries. This produced 40.17 M map-able sequences, of which we identified 204 conserved miRNAs, and 190 novel candidate miRNAs. Furthermore, we identified 34 miRNAs specifically expressed in only one library, all with well-characterized immunerelated functions. A set of five universally abundant miRNAs (miR-148a-3p, miR-21-5p, let-7f-5p, let-7i-5p, and miR-99a-5p) across all four biofluids was also found. Function enrichment analysis revealed that the target genes of the five ubiquitous miRNAs are primarily involved in immune and RNA metabolic processes. In summary, our findings suggest that porcine biofluid exosomes contain a large number of miRNAs, many of which may be crucial regulators of the immune system.

Expression Pattern of Seminal Plasma Extracellular Vesicle Small RNAs in Boar Semen

“…SP-EVs have previously been shown to be present in seminal plasma of various species, including humans (15), mouse (17), bovines (18), and boars (8,21,24,35). Here, the existence of boar SP-EVs was validated by TEM, NTA, and Western blotting at the same time.…”

Identification of microRNAs in Silver Carp (Hypophthalmichthys molitrix) Response to Hypoxia Stress

“…In addition, relevant study has also found that miRNA played an important role in fat metabolism in extreme environments, which wasconsistent with the significant enrichment of lipid metabolism pathways in this study [ 35 ]. The results showed that under hypoxia conditions, most of the differentially expressed target genes of miRNAs were related to cell apoptosis, immunity and lipid metabolism [ 36 , 37 ]. This study explores the expression of miRNA in silver carp under different levels of hypoxia stress, and provides the reference for carrying out miRNA-target gene interaction in the later stage, improving the survival ability of silver carp under hypoxia environment.…”

Extracellular vesicles in seminal fluid and effects on male reproduction. An overview in farm animals and pets

“…They also noted that pig sEVs are rich in PIWI-interacting RNAs (piRNAs, they found 19,749), although they did not link them to any reproductive function because of the lack of consultative databases. Also in pigs, Zhang et al (2020) explored the miRNA cargo of EVs isolated from urine, blood plasma, SP and bile, and found that all EVs expressed well-defined miRNAs related to immune functions. Also recently, Twenter et al (2020) explored the miRNAs cargo of equine sEVs from caput, corpus and cauda epididymis, showing some of the identified miRNAs putative roles in sperm motility and viability and also in oocyte maturation and embryo development.…”

“…Accordingly, sEVs would play and essential role in regulating the immune response of the female genital tract, facilitating the survival and functionality of sperm and subsequent embryo and placental development. It should be noted that sEVs, like those present in other body fluids, contain a large number of miRNAs with welldocumented immune-related functions (Zhang et al, 2020).…”