MicroRNA Bta-miR-24-3p Suppressed Galectin-9 Expression through TLR4/NF-ĸB Signaling Pathway in LPS-Stimulated Bovine Endometrial Epithelial Cells

Extracellular vesicles-coupled miRNAs from oviduct and uterus modulate signaling pathways related to lipid metabolism and bovine early embryo development

BACKGROUND

Extracellular vesicles (EVs) present in oviductal (OF) and uterine fluid (UF) have been shown to enhance bovine embryo quality during in vitro culture by reducing lipid contents and modulating lipid metabolism-related genes (LMGs), while also influencing cell proliferation, suggesting their involvement on the regulation of different biological pathways. The regulation of signaling pathways related to cell differentiation, proliferation, and metabolism is crucial for early embryo development and can determine the success or failure of the pregnancy. Bioactive molecules within EVs in maternal reproductive fluids, such as microRNAs (miRNAs), may contribute to this regulatory process as they modulate gene expression through post-transcriptional mechanisms.

RESULTS

From the 20 differentially expressed miRNAs, 19 up-regulated in UF-EVs (bta-miR-134, bta-miR-151-3p, bta-miR-155, bta-miR-188, bta-miR-181b, bta-miR-181d, bta-miR-224, bta-miR-23b-3p, bta-miR-24-3p, bta-miR-27a-3p, bta-miR-29a, bta-miR-324, bta-miR-326, bta-miR-345-3p, bta-miR-410, bta-miR-652, bta-miR-677, bta-miR-873 and bta-miR-708) and one (bta-miR-148b) in OF-EVs. These miRNAs were predicted to modulate several pathways such as Wnt, Hippo, MAPK, and lipid metabolism and degradation. Differences in miRNAs found in OF-EVs from the early luteal phase and UF-EVs from mid-luteal phase may reflect different environments to meet the changing needs of the embryo. Additionally, miRNAs may be involved, particularly in the uterus, in the regulation of embryo lipid metabolism, immune system, and implantation. This study evaluated miRNA cargo in OF-EVs from the early luteal phase and UF-EVs from the mid-luteal phase, coinciding with embryo transit within oviduct and uterus in vivo, and its possible influence on LMGs and signaling pathways crucial for early embryo development. A total of 333 miRNAs were detected, with 11 exclusive to OF, 59 to UF, and 263 were common between both groups.

CONCLUSIONS

Our study suggests that miRNAs within OF- and UF-EVs could modulate bovine embryo development and quality, providing insights into the intricate maternal-embryonic communication that might be involved in modulating lipid metabolism, immune response, and implantation during early pregnancy.

Label-free and highly sensitive detection of microRNA from cancer cells via target-induced cascade amplification generation of lighting-up RNA aptamers

The abnormal expression levels of miRNAs have been proven to be highly related to the generation of various diseases and are also closely associated with the stages and types of disease development. The novel RNA aptamers-based homogenous fluorescent methods were simple, with low background signal and high signal-to-noise ratio, but lacked effective signal amplification technology to achieve sensitive detection of trace miRNA markers. There is an urgent need for combining effective nucleic acid amplification technology with RNA aptamer to achieve highly sensitive and accurate detection of miRNA. For this purpose, a new DNA multi-arm nanostructure-based dual rolling circle transcription machinery for the generation of lighting-up MG RNA aptamers is constructed for label-free and highly sensitive sensing of miRNA-21. In this system, the target miRNA-21 induces a structural transformation of the DNA multi-arm nanostructure probe to recycle miRNA-21 and trigger two independent rolling circle transcription reactions to generate two long RNAs, which can partially hybridize with each other to generate large amounts of complete MG RNA aptamers. These RNA aptamers can associate with organic MG dye to produce significantly enhanced fluorescence signals to accomplish ultrasensitive miRNA-21 detection down to 0.9 fM. In addition, this method exhibits high selectivity to distinguish miRNA-21 even with single nucleotide mismatch, and also has potential application capability to monitor different expression levels of miRNA-21 from different cancer cells. The effective collaboration between MG RNA aptamer and rolling circle transcription reaction makes this fluorescent method show the significant advantages of low background signal, high signal-to-noise ratio and high detection sensitivity. It has great potential to be a promising means to achieve label-free and highly sensitive monitoring of other trace biological markers via a simple change of target sequence.

miR-92b-5p negatively regulates IKK through targeting its ORF region in the innate immune responses of amphioxus (Branchiostoma belcheri)

Cephalochordate (Amphioxus), situated at a key phylogenetic position in the phylum Chordata, serves as a model organism for studying the origin and evolution of the vertebrate innate immune. In this study, five members of precursor miR-92 family (miR-92a-1, miR-92a-2, miR-92b, miR-92c and miR-92d) are identified in Branchiostoma belcheri, and their evolutionary conservation and potential molecular functions in innate immunity are analyzed. Among them, miR-92b-5p was validated in HEK293 cells to target the coding region but not classic 3'UTR of IKK (inhibitor of nuclear factor kappa-B kinase) mRNA, one integral component of MAPK and TLR4 immune signaling. Furthermore, the spatiotemporal expression patterns of miR-92b-5p and IKK were examined in different tissues or different time points (2 h, 4 h, 8 h, 12 h, 24 h and 48 h) post LPS stimulation at RNA and protein level in vivo. The seemingly inverse expression pattern between miR-92b-5p and IKK supports the involvement of miR-92b-5p in Branchiostoma belcheri innate immune response. In conclusion, our work not only illustrates the evolutionary pattern of Branchiostoma belcheri miR-92 family across chordates, but also reveals that miR-92b-5p could target IKK expression to regulate innate immune response.

Epigallocatechin-3-gallate (EGCG) attenuates inflammatory responses and oxidative stress in lipopolysaccharide (LPS)-induced endometritis via silent information regulator transcript-1 (SIRT1)/nucleotide oligomerization domain (NOD)-like receptor pyrin domain-containing 3 (NLRP3) pathway

The protective effects of epigallocatechin-3-gallate (EGCG) on lipopolysaccharide (LPS)-induced endometritis in vivo and in vitro will be explored in this study. The endometritis model was induced in female BALB/c mice uterus by perfusion with lipopolysaccharide (LPS) and EGCG were administered at 1 h before LPS induction. The primary bovine endometrial epithelial cells (BEECs) were treated with EGCG for 1 h before LPS stimulation. Uterine histopathological changes, myeloperoxidase (MPO) activity, inflammatory cytokine levels and oxidative stress markers were determined. The extent of Bax, Bcl-2, cleaved caspase-3, silent information regulator transcript-1 (SIRT1), nucleotide oligomerization domain (NOD)-like receptor pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC) and Caspase1 was detected by Western blot and real-time quantitative PCR assays. The results showed that EGCG significantly reversed the LPS-induced uterine histopathological changes, MPO activity, pro-inflammatory cytokine levels. Additionally, EGCG decreased oxidative stress and reduced cell apoptosis by upregulating SIRT1 expression, downregulating the NLRP3 inflammasome activation. These findings indicated that EGCG exerted its greatest protective effects by blocking inflammatory responses, lowering oxidative stress, and reducing apoptosis via the SIRT1/NLRP3, making its promising candidate treatment for endometritis.

Active components and molecular mechanism of Syringa oblata Lindl. in the treatment of endometritis based on pharmacology network prediction

Antibiotic treatment of endometritis was limited by the inevitable antibiotic residues and risk of bacterial resistance. Therefore, the development of safe and effective strategies for endometritis treatment is urgently needed. Syringa oblata Lindl. (SOL) showed great pharmacological potential against endometritis. However, the active components and underlying mechanism of SOL for endometritis treatment remain indeterminate. In our study, the active components and possible molecular mechanism of SOL against endometritis were predicted through computer data mining and biological networks construction. It was predicted that the main active components of SOL were luteolin, kaempferol, oleanolic acid, and rutin, and their anti-endometritis effect was mainly attributed to the TLRs/NF-κB signaling pathway. Furthermore, a green and efficient deep eutectic solvent combined with ultrasound-assisted extraction (DES-UAE) was performed and optimized to obtain high contents of total flavonoid, rutin, and luteolin. The four predicted active components in the SOL extracts were qualitatively and quantitatively analyzed by LC/MS and HPLC. Finally, the pharmacological effects of SOL and active components have been verified by Staphylococcus aureus-endometritis models in mice. H&E staining and bacterial load in uterus tissues assays initially validated the pharmacodynamic effects of SOL, and quantitative real-time PCR (RT-qPCR) and ELISA results confirmed that SOL and four active components could ameliorate the uterus injury caused by Staphylococcus aureus, the mechanism of action is related to the TLRs/NF-κB signaling pathway.