MicroRNAs: history, biogenesis, and their evolving role in animal development and disease

miRNA Regulatory Functions in Farm Animal Diseases, and Biomarker Potentials for Effective Therapies

MicroRNAs (miRNAs) are small endogenous RNAs that regulate gene expression post-transcriptionally by targeting either the 3′ untranslated or coding regions of genes. They have been reported to play key roles in a wide range of biological processes. The recent remarkable developments of transcriptomics technologies, especially next-generation sequencing technologies and advanced bioinformatics tools, allow more in-depth exploration of messenger RNAs (mRNAs) and non-coding RNAs (ncRNAs), including miRNAs. These technologies have offered great opportunities for a deeper exploration of miRNA involvement in farm animal diseases, as well as livestock productivity and welfare. In this review, we provide an overview of the current knowledge of miRNA roles in major farm animal diseases with a particular focus on diseases of economic importance. In addition, we discuss the steps and future perspectives of using miRNAs as biomarkers and molecular therapy for livestock disease management as well as the challenges and opportunities for understanding the regulatory mechanisms of miRNAs related to disease pathogenesis.

LncRNA POU3F3 Contributes to Dacarbazine Resistance of Human Melanoma Through the MiR-650/MGMT Axis

Background: Alkylating agents are critical therapeutic options for melanoma, while dacarbazine (DTIC)-based chemotherapy showed poor sensitivity in clinical trials. Long non-coding RNAs (lncRNAs) were highlighted in the progression of malignant tumors in recent years, whereas little was known about their involvement in melanoma.

Methods: The functional role and molecular mechanism of lncRNA POU3F3 were evaluated on DTIC-resistant melanoma cells. Further studies analyzed its clinical role in the disease progression of melanoma.

Results: We observed elevated the expression of lncRNA POU3F3 in the DTIC-resistant melanoma cells. Gain-of-function assays showed that the overexpression of lncRNA POU3F3 maintained cell survival with DTIC treatment, while the knockdown of lncRNA POU3F3 restored cell sensitivity to DTIC. A positive correlation of the expression O6-methylguanine-DNA-methyltransferase (MGMT) was observed with lncRNA POU3F3 in vitro and in vivo. Bioinformatic analyses predicted that miR-650 was involved in the lncRNA POU3F3-regulated MGMT expression. Molecular analysis indicated that lncRNA POU3F3 worked as a competitive endogenous RNA to regulate the levels of miR-650, and the lncRNA POU3F3/miR-650 axis determined the transcription of MGMT in melanoma cells to a greater extent. Further clinical studies supported that lncRNA POU3F3 was a risk factor for the disease progression of melanoma.

Conclusion: LncRNA POU3F3 upregulated the expression of MGMT by sponging miR-650, which is a crucial way for DTIC resistance in melanoma. Our results indicated that lncRNA POU3F3 was a valuable biomarker for the disease progression of melanoma.

MiR-1290 promotes myoblast differentiation and protects against myotube atrophy via Akt/p70/FoxO3 pathway regulation

BACKGROUND

Sarcopenia is a common skeletal disease related to myogenic disorders and muscle atrophy. Current clinical management has limited effectiveness. We sought to investigate the role of miR-1290 in myoblast differentiation and muscle atrophy.

METHODS

By transfecting miR-1290 into C2C12 cells, we investigated whether miR-1290 regulates myogenesis and myotube atrophy via AKT/P70 signaling pathway. MHC staining was performed to assess myoblast differentiation. Differentiation-related MHC, Myod, and Myog protein levels, and atrophy-related MuRF1 and atrogin-1 were explored by western blot. An LPS-induced muscle atrophy rat model was developed. RT-PCR was conducted to analyze miR-1290 serum levels in muscle atrophy patients and normal controls (NCs).

RESULTS

The miR-1290 transfection increased MHC-positive cells and MHC, Myod, and Myog protein levels in the miR-1290 transfection group, demonstrating that miR-1290 promoted C2C12 myoblast differentiation. Myotube diameter in the miR-1290 transfection group was higher than in the TNF-α-induced model group. Western blot analysis showed decreased MuRF1 and atrogin-1 levels in the miR-1290 transfection group compared with the model group, demonstrating that miR-1290 protected against myoblast cellular atrophy. Luciferase assay and western blot analysis showed that miR-1290 regulation was likely caused by AKT/p70/FOXO3 phosphorylation activation. In the LPS-induced muscle atrophy rat model, miR-1290 mimics ameliorated gastrocnemius muscle loss and increased muscle fiber cross-sectional area. Clinically, miR-1290 serum level was significantly decreased in muscle atrophy patients.

CONCLUSIONS

We found that miR-1290 enhances myoblast differentiation and inhibits myotube atrophy through Akt/p70/FoxO3 signaling in vitro and in vivo. In addition, miR-1290 may be a potential therapeutic target for sarcopenia treatment.

MiR-92 Family Members Form a Cluster Required for Notochord Tubulogenesis in Urochordate Ciona savignyi

MicroRNAs are frequently clustered in the genome and polycistronically transcribed, regulating targeted genes in diverse signaling pathways. The miR-17-92 cluster is a typical miRNA cluster, playing crucial roles in the organogenesis and homeostasis of physiological processes in vertebrates. Here, we identified three miRNAs (csa-miR-92a, csa-miR-92b, and csa-miR-92c) that belonged to the miR-92 family and formed a miRNA cluster in the genome of a urochordate marine ascidian Ciona savignyi. Except for miR-92a and miR-92b, other homologs of the vertebrate miR-17-92 cluster members could not be identified in the Ciona genome. We further found that the mature sequences of urochordate miR-92 family members were highly conserved compared with the vertebrate species. The expression pattern revealed that three miR-92 family members had consistent expression levels in adult tissues and were predominantly expressed in heart and muscle tissue. We further showed that, at the embryonic and larval stages, csa-miR-92c was expressed in the notochord of embryos during 18–31 h post fertilization (hpf) by in situ hybridization. Knockout of csa-miR-92c resulted in the disorganization of notochord cells and the block of lumen coalescence in the notochord. Fibroblast growth factor (FGF), mitogen-activated protein kinase (MAPK), and wingless/integrated (Wnt)/planar cell polarity (PCP) signaling pathways might be involved in the regulatory processes, since a large number of core genes of these pathways were the predicted target genes of the miR-92 family. Taken together, we identified a miR-92 cluster in urochordate Ciona and revealed the expression patterns and the regulatory roles of its members in organogenesis. Our results provide expression and phylogenetic data on the understanding of the miR-92 miRNA cluster’s function during evolution.

Quercetin suppresses cell survival and invasion in oral squamous cell carcinoma via the miR-1254/CD36 cascade in vitro

OBJECTIVE

This study aimed to investigate the effects of quercetin on the proliferation and invasion in oral squamous cell carcinoma (OSCC) and examine its effect on the activation of the miR-1254/CD36 signaling pathway.

METHODS

Proliferation and invasion experiments were performed in the OSCC cell line CAL-27 in which miR-1254 was overexpressed or inhibited. The levels of miR-1254 and CD36 were determined using quantitative real-time polymerase chain reaction and Western blotting assays.

RESULTS

Quercetin significantly suppressed the proliferation and invasion of CAL-27 cells in a dose-dependent manner, while up-regulating miR-1254 and down-regulating CD36. The overexpression of miR-1254 also considerably down-regulated CD36 and enhanced the ability of quercetin to inhibit CAL-27 cell survival and invasion. Conversely, the inhibition of miR-1254 significantly up-regulated CD36 and antagonized the inhibitory effects of quercetin.

CONCLUSION

Our study suggests that quercetin might suppress the progression of OSCC by activating the miR-1254/CD36 signaling pathway, indicating its potential as a treatment against OSCC.

MiR-520a-3p Inhibited Macrophage Polarization and Promoted the Development of Atherosclerosis via Targeting UVRAG in Apolipoprotein E Knockout Mice

Atherosclerosis (AS), a kind of chronic inflammatory blood vessel disease, is a main cause of cardiovascular disease, which is a leading cause of mortality around the world. Accumulation of macrophages induced by inflammation contributes to AS development. It has been indicated that microRNAs (miRNAs) are involved in the process of AS. However, the pathway and gene miRNAs targeting are poorly understood. Here we reported that miR-520a-3p was increased in mice with AS and silencing of miR-520a-3p attenuated AS process. Furthermore, inhibition of miR-520a-3p increased the expression of α-SMA and collagen. In addition, miR-520a-3p silencing inhibited the expression of M1 macrophage polarization markers and pro-inflammatory genes and promoted the M2 macrophage polarization. What’s more, forced expression of miR-520a-3p diminished IL4/IL13 induced macrophage autophagy via targeting UVRAG. Collectively, our study reveals the role of miR-520a-3p in macrophage polarization and suggests the potential of miRNA as a novel treatment target of AS.

N6-Methyladenosine Induced miR-34a-5p Promotes TNF-α-Induced Nucleus Pulposus Cell Senescence by Targeting SIRT1

Low back pain is tightly associated with intervertebral disc degeneration (IVDD) and aberrant nucleus pulposus (NP) is a critical cause. miRNAs N6-methyladenosine (m6A) modification accounts for the TNF-α-induced senescence of NP cells. The aim of this study was to investigate whether m6A modification regulates TNF-α-mediated cell viability, cell cycle arrest, and cell senescence and how it works. The results showed that METTL14 expression positively correlated with m6A and TNF-α expression in HNPCs. The knockdown of METTL14 led to the inhibition of the TNF-α-induced cell senescence. METTL14 overexpression promoted cell senescence. METTL14 regulated the m6A modification of miR-34a-5p and interacted with DGCR8 to process miR-34a-5p. The miR-34a-5p inhibitor inhibited the cell cycle senescence of HNPCs. miR-34a-5p was predicted to interact with the SIRT1 mRNA. SIRT1 overexpression counteracted the miR-34a-5p-promoted cell senescence. METTL14 participates in the TNF-α-induced m6A modification of miR-34a-5p to promote cell senescence in HNPCs and NP cells of IVDD patients. Downregulation of either METTL14 expression or miR-34a-5p leads to the inhibition of cell cycle arrest and senescence. SIRT1 mRNA is an effective binding target of miR-34a-5p, and SIRT1 overexpression mitigates the cell cycle arrest and senescence caused by miR-34a-5p.

LncRNAs and microRNAs as Essential Regulators of Stemness in Breast Cancer Stem Cells

Breast cancer is an aggressive disease with a high incidence in women worldwide. Two decades ago, a controversial hypothesis was proposed that cancer arises from a subpopulation of “tumor initiating cells” or “cancer stem cells-like” (CSC). Today, CSC are defined as small subset of somatic cancer cells within a tumor with self-renewal properties driven by the aberrant expression of genes involved in the maintenance of a stemness-like phenotype. The understanding of the underlying cellular and molecular mechanisms involved in the maintenance of CSC subpopulation are fundamental in the development and persistence of breast cancer. Nowadays, the hypothesis suggests that genetic and epigenetic alterations give rise to breast cancer stem cells (bCSC), which are responsible for self-renewal, tumor growth, chemoresistance, poor prognosis and low survival in patients. However, the prominence of bCSC, as well as the molecular mechanisms that regulates and promotes the malignant phenotypes, are still poorly understood. The role of non-coding RNAs (ncRNAs), such as long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) acting as oncogenes or tumor suppressor genes has been recently highlighted by a plethora of studies in breast cancer. These ncRNAs positively or negatively impact on different signaling pathways that govern the cancer hallmarks associated with bCSC, making them attractive targets for therapy. In this review, we present a current summary of the studies on the pivotal roles of lncRNAs and microRNAs in the regulation of genes associated to stemness of bCSC.

Candida albicans Induces Cross-Kingdom miRNA Trafficking in Human Monocytes To Promote Fungal Growth

In response to infections, human immune cells release extracellular vesicles (EVs) that carry a situationally adapted cocktail of proteins and nucleic acids, including microRNAs (miRNAs), to coordinate the immune response. In this study, we identified hsa-miR-21-5p and hsa-miR-24-3p as the most common miRNAs in exosomes released by human monocytes in response to the pathogenic fungus Candida albicans. Functional analysis of miRNAs revealed that hsa-miR-24-3p, but not hsa-miR-21-5p, acted across species and kingdoms, entering C. albicans and inducing fungal cell growth by inhibiting translation of the cyclin-dependent kinase inhibitor Sol1. Packaging of hsa-miR-24-3p into monocyte exosomes required binding of fungal soluble β-glucan to complement receptor 3 (CR3) and binding of mannan to Toll-like receptor 4 (TLR4), resulting in receptor colocalization. Together, our in vitro and in vivo findings reveal a novel cross-species evasion mechanism by which C. albicans exploits a human miRNA to promote fungal growth and survival in the host. IMPORTANCE Over the last decade, communication between immune cells by extracellular vesicle-associated miRNAs has emerged as an important regulator of the coordinated immune response. Therefore, a thorough understanding of the conversation occurring via miRNAs, especially during infection, may provide novel insights into both the host reaction to the microbe as well as the microbial response. This study provides evidence that the pathogenic fungus C. albicans communicates with human monocytes and induces the release of a human miRNA that promotes fungal growth. This mechanism represents an unexpected cross-species interaction and implies that an inhibition of specific miRNAs offers new possibilities for the treatment of human fungal infections.

Effects of circular RNA Ttc3/miR-148a/Rcan2 axis on inflammation and oxidative stress in rats with acute kidney injury induced by sepsis

Aim Increasing evidence demonstrated circular RNAs (circRNAs) are involved in the development of various diseases, including sepsis-induced AKI. Although CIRC-Ttc3 has been proved to regulate cardiac function after myocardial infarction, its role in sepsis-induced AKI remains unclear.

MATERIALS AND METHODS

The AKI rat model was firstly induced by sepsis through cecal ligation puncture (CLP). Serum levels of creatinine, BUN, NGAL, TNF-α, IL-6, SOD, MDA and IL-1β were measured through appropriate kits. The pathological alteration and renal microvascular permeability in renal tissues were determined by HE staining and Evans Blue assays. Cell apoptosis was detected by TUNEL assay. The expression levels of CIRC-Ttc3, miR-148a, TNF-α, IL-1β and iNOS in rats' renal samples were tested by qRT-PCR or/and western blot. The binding ability between CIRC-Ttc3 and miR-148a was evaluated through luciferase reporter, RIP and RNA pull-down assays.

KEY FINDINGS

Kidney injury was found in CLP-treated rats. CIRC-Ttc3 expression was down-regulated, and upregulation of CIRC-Ttc3 improved inflammatory responses and oxidative stress in AKI rats. Mechanismly, CIRC-Ttc3 was confirmed to bind to and negatively regulate miR-148a. Further rescue assays revealed that overexpression of miR-148a rescued the improvement of CIRC-Ttc3 on sepsis-induced AKI. Then, it was illustrated that CIRC-Ttc3 regulated Rcan2 expression by binding to miR-148a. Finally, knockdown of Rcan2 reversed the effects of miR-148a inhibition on sepsis-induced AKI.

SIGNIFICANCE

CIRC-Ttc3 relieved inflammation and oxidative stress through regulating the miR-148a/Rcan2 axis in rats with AKI induced by sepsis. Therefore, CIRC-Ttc3 may be a potential therapeutic target for sepsis-induced AKI.

Umbilical mesenchymal stem cell-derived exosomes facilitate spinal cord functional recovery through the miR-199a-3p/145-5p-mediated NGF/TrkA signaling pathway in rats

Background

Although exosomes, as byproducts of human umbilical cord mesenchymal stem cells (hUC-MSCs), have been demonstrated to be an effective therapy for traumatic spinal cord injury (SCI), their mechanism of action remains unclear.

Methods

We designed and performed this study to determine whether exosomes attenuate the lesion size of SCI by ameliorating neuronal injury induced by a secondary inflammatory storm and promoting neurite outgrowth. We determined the absolute levels of all exosomal miRNAs and investigated the potential mechanisms of action of miR-199a-3p/145-5p in inducing neurite outgrowth in vivo and in vitro.

Results

miR-199a-3p/145-5p, which are relatively highly expressed miRNAs in exosomes, promoted PC12 cell differentiation suppressed by lipopolysaccharide (LPS) in vitro through modulation of the NGF/TrkA pathway. We also demonstrated that Cblb was a direct target of miR-199a-3p and that Cbl was a direct target of miR-145-5p. Cblb and Cbl gene knockdown resulted in significantly decreased TrkA ubiquitination levels, subsequently activating the NGF/TrkA downstream pathways Akt and Erk. Conversely, overexpression of Cblb and Cbl was associated with significantly increased TrkA ubiquitination level, subsequently inactivating the NGF/TrkA downstream pathways Akt and Erk. Western blot and coimmunoprecipitation assays confirmed the direct interaction between TrkA and Cblb and TrkA and Cbl. In an in vivo experiment, exosomal miR-199a-3p/145-5p was found to upregulate TrkA expression at the lesion site and also promote locomotor function in SCI rats.

Conclusions

In summary, our study showed that exosomes transferring miR-199a-3p/145-5p into neurons in SCI rats affected TrkA ubiquitination and promoted the NGF/TrkA signaling pathway, indicating that hUC-MSC-derived exosomes may be a promising treatment strategy for SCI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02148-5.

Long Non-Coding RNA ELFN1-AS1 Promoted Colon Cancer Cell Growth and Migration via the miR-191-5p/Special AT-Rich Sequence-Binding Protein 1 Axis

Long non-coding RNAs (lncRNAs) are reported to participate in tumor development. It has been manifested in previous researches that lncRNA ELFN1-AS1 is involved in early-stage colon adenocarcinoma with potential diagnostic value. However, no studies have revealed the specific mechanism of ELFN1-AS1 in colon cancer, and there are no other studies on whether ELFN1-AS1 is associated with tumorigenesis. In our study, ELFN1-AS1 with high expression in colon cancer was selected by TCGA analysis, and the survival analysis was carried out to verify it. Subsequently, qRT-PCR was adopted for validating the results in tissues and cell lines. Cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), cell colon, cell apoptosis, cell cycle, cell migration, and invasion assays were utilized to assess the role of ELFN1-AS1 in colon cancer. Results uncovered that ELFN1-AS1 expression was prominently raised in colon cancer cells and tissues. ELFN1-AS1 decrement restrained cells to grow through interfering with distribution of cell cycle and promoting apoptosis. Meanwhile, ELFN1-AS1 decrement weakened the capacity of cells to migrate and invade. What's more, ELFN1-AS1 was uncovered to act as a competing endogenous RNA (ceRNA) to decrease miR-191-5p expression, thus raising special AT-rich sequence-binding protein 1 (SATB1), a downstream target of ceRNA. To sum up, ELFN1-AS1 drives colon cancer cells to proliferate and invade through adjusting the miR-191-5p/SATB1 axis. The above results disclose that lncRNA ELFN1-AS1 is possibly a novel treatment target for colon cancer cases.

MicroRNA regulation of vascular smooth muscle cells and its significance in cardiovascular diseases

Cardiovascular disease (CVD) is among the leading causes of death worldwide. MicroRNAs (miRNAs), regulatory molecules that repress protein expression, have attracted considerable attention in CVD research. The vasculature plays a big role in CVD development and progression and dysregulation of vascular cells underlies the root of many vascular diseases. This review provides a brief introduction of the biogenesis of miRNAs and exosomes, followed by overview of the regulatory mechanisms of miRNAs in vascular smooth muscle cells (VSMCs) intracellular signaling during phenotypic switching, senescence, calcification, and neointimal hyperplasia. Evidence of extracellular signaling of VSMCs and other cells via exosomal and circulating miRNAs is also presented. Lastly, current drawbacks and limitations of miRNA studies in CVD research and potential ways to overcome these disadvantages are discussed in detail. In-depth understanding of VSMC regulation via miRNAs will add substantial knowledge and advance research in diagnosis, disease progression, and (or) miRNA-derived therapeutic approaches in CVD research.

microRNA in inflammatory bowel disease at a glance

Inflammatory bowel disease (IBD) as a chronic inflammation in colon and small intestine has two subtypes: ulcerative colitis (UC) and Crohn's disease (CD). Genome studies have shown that UC and CD are related to microRNAs (miRNAs) expression in addition to environmental factors. This article reviews important researches that have recently been done on miRNAs roles in CD and UC disease. First, miRNA is introduced and its biogenesis and function are discussed. Afterward, roles of miRNAs in inflammatory processes involved in IBD are showed. Finally, this review proposes some circulating and tissue-specific miRNAs, which are useful for CD and UC fast diagnosis and grade prediction. As a conclusion, miRNAs are efficient diagnostic molecules especially in IBD subtypes discrimination and can be used by microarray and real time PCR methods for disease detection and classification.

Improvement, identification, and target prediction for miRNAs in the porcine genome by using massive, public high-throughput sequencing data

Despite the broad variety of available microRNA (miRNA) research tools and methods, their application to the identification, annotation, and target prediction of miRNAs in nonmodel organisms is still limited. In this study, we collected nearly all public sRNA-seq data to improve the annotation for known miRNAs and identify novel miRNAs that have not been annotated in pigs (Sus scrofa). We newly annotated 210 mature sequences in known miRNAs and found that 43 of the known miRNA precursors were problematic due to redundant/missing annotations or incorrect sequences. We also predicted 811 novel miRNAs with high confidence, which was twice the current number of known miRNAs for pigs in miRBase. In addition, we proposed a correlation-based strategy to predict target genes for miRNAs by using a large amount of sRNA-seq and RNA-seq data. We found that the correlation-based strategy provided additional evidence of expression compared with traditional target prediction methods. The correlation-based strategy also identified the regulatory pairs that were controlled by nonbinding sites with a particular pattern, which provided abundant complementarity for studying the mechanism of miRNAs that regulate gene expression. In summary, our study improved the annotation of known miRNAs, identified a large number of novel miRNAs, and predicted target genes for all pig miRNAs by using massive public data. This large data-based strategy is also applicable for other nonmodel organisms with incomplete annotation information.

miRNA-Based Therapeutics in the Era of Immune-Checkpoint Inhibitors

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by binding to complementary target regions on gene transcripts. Thus, miRNAs fine-tune gene expression profiles in a cell-type-specific manner and thereby regulate important cellular functions, such as cell growth, proliferation and cell death. MiRNAs are frequently dysregulated in cancer cells by several mechanisms, which significantly affect the course of the disease. In this review, we summarize the current knowledge on how dysregulated miRNAs contribute to cancer and how miRNAs can be exploited as predictive factors and therapeutic targets, particularly in regard to immune-checkpoint inhibitor therapies.

Hepatitis A virus-induced hsa-miR-146a-5p attenuates IFN-β signaling by targeting adaptor protein TRAF6

Hepatitis A virus (HAV), a unique hepatotropic human picornavirus, is the causative agent of acute hepatitis A in humans. Some studies have shown that HAV antagonizes the innate immune response by disrupting interferon-beta (IFN-β) signaling by viral proteins. However, whether microRNAs (miRNAs), a class of non-coding RNAs, are involved in the antagonism of IFN-β induction upon HAV infection is still unclear. In this study, we investigated the effects and mechanisms by which HAV-induced miRNAs antagonize IFN-β signaling. A variety of analytical methods, including miRNA microarray, RT-qPCR, dual-luciferase reporter assay, and Western blotting, were performed using HAV-infected cells. The results indicated that HAV infection upregulates the expression of hsa-miR-146a-5p, which in turn partially suppresses the induction of IFN-β synthesis, thereby promoting viral replication. Mechanistically, TRAF6 (TNF receptor-associated factor 6), a key adaptor protein in the RIG-I/MDA5-mediated IFN-I signaling pathway, is targeted and degraded by hsa-miR-146a-5p. As TRAF6 is necessary for IFN-β induction, inhibition of this protein attenuates IFN-β signaling. Taken together, the results from this study indicated that HAV disrupts RIG-I/MDA5-mediated IFN-I signaling partially through the cleavage of the essential adaptor molecule TRAF6 via hsa-miR-146a-5p.

MiR-491-5p, as a Tumor Suppressor, Prevents Migration and Invasion of Breast Cancer by Targeting ZNF-703 to Regulate AKT/mTOR Pathway

Background

Large amounts of microRNAs (miRNAs) have been reported to be aberrantly expressed in malignant cancers. MiR-491-5p makes a significant contribution to the inhibition of multiple cancer processes. However, the specific mechanism and function of miR-491-5p and in breast cancer (BC) is still not fully elucidated.

Methods

MiR-491-5p and ZNF-703 expressions or gene transfection effects were identified by RT-qPCR or Western blot in BC tissues or cells. And ZNF-703 expression was monitored through immunohistochemistry method. Cellular function was also confirmed using Transwell assay. Besides, AKT/mTOR pathway-related proteins were analyzed using Western blotting analysis. Moreover, the interplay between miR-491-5p and ZNF-703 was verified through dual-luciferase reporter assay.

Results

miR-491-5p was lowly expressed, ZNF-703 was highly expressed in BC, and miR-491-5p with low expression and ZNF-703 with high expression were associated with poor prognosis of BC patients. Results of cellular function revealed that overexpression of miR-491-5p markedly suppressed BC cell migration and invasion, and knockdown of miR-491-5p had the opposite effect. Besides, mechanism research disclosed that miR-491-5p directly could bind to ZNF-703 and downregulate ZNF-703. Moreover, we proved that ZNF-703 could prominently reverse the influences of miR-491-5p on the migration and invasion of BC cells. More importantly, the data revealed that miR-491-5p repressed AKT/mTOR pathway by ZNF-703 in BC cells.

Conclusion

MiR-491-5p prominently suppresses the metastasis of BC cells through ZNF-703 to regulate AKT/mTOR pathway, indicating that miR-491-5p and ZNF-703 might be served as the potential therapeutic targets for BC.

RNA Interference: Story and Mechanisms

The discovery that gene expression can be silenced by exogenously introduced double-stranded RNAs into cells unveiled a hidden level of gene regulation by a variety of small RNA pathways, which are involved in regulating endogenous gene expression, defending against virus infections, and protecting the genome from invading transposons, both at the posttranscriptional and epigenetic levels. All endogenous RNA interference pathways share a conserved effector complex, which contains at least an argonaute protein and a short single-stranded RNA. Such argonaute-RNA complexes can repress the transcription of genes, target mRNA for site-specific cleavage, or block mRNA translation into proteins. This review outlines the history of RNAi discovery, function, and mechanisms of action. For comparison, it also touches on CRISPR interference.

Regulation of inflammatory and catabolic responses to IL-1β in rat articular chondrocytes by microRNAs miR-122 and miR-451

OBJECTIVE

miR-122 stimulates proliferation of growth plate chondrocytes whereas miR-451 stimulates terminal differentiation and matrix turnover. Here, we examined the potential of these microRNA as regulators of articular chondrocytes using an in vitro model of osteoarthritis.

METHODS

miR-122 and miR-451 presence in rat articular cartilage was assessed using the anterior cruciate ligament transection model of OA. In vitro testing used first passage rat articular chondrocytes (rArCs) that were transfected with lipofectamine (Lipo) and miR-122 or miR-451 for 24-h, then treated with 10 ng/mL IL-1β in order to mimic an osteoarthritic environment. Conditioned media were collected and MMP13, PGE2 and OA-related cytokines were measured. Matrix vesicles were collected from cell layer lysates using ultra-centrifugation. Cells were treated with miR-122 or miR-451 inhibitors to verify miR-specific effects.

RESULTS

Both miR-122 and miR-451 were increased in the OA articular cartilage compared to healthy tissue; rArCs expressed both microRNAs in MVs. miR-122 prevented IL-1β-dependent increases in MMP-13 and PGE2, whereas miR-451 significantly increased the IL-1β effect. Multiplex data indicated that miR-122 reduced the stimulatory effect of IL-1β on IL-1α, IL-2, Il-4, IL-6, GM-CSF, MIP-1A, RANTES and VEGF. In contrast, IL-2, IL-4, IL-6, GM-CSF, and MIP-1A were increased by miR-451 while VEGF was decreased. Inhibiting miR-122 exacerbated the response to IL-1β indicating endogenous levels of miR-122 were present. There were no differences in MMP-13 or PGE2 with miR-451 Locked Nucleic Acid (LNA) inhibitor treatment.

CONCLUSIONS

Both miRs were elevated in OA in a rat bilateral anterior cruciate ligament transection (ACLT) model. miR-122 prevented, while miR-451 exacerbated the effects of IL-1β on rArCs.

Non-alcoholic fatty liver disease: molecular and cellular interplays of the lipid metabolism in a steatotic liver

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) affects ~25% of world population and cases have increased in recent decades. These anomalies have several etiologies; however, obesity and metabolic dysfunctions are the most relevant causes. Despite being considered a public health problem, no effective therapeutic approach to treat NAFLD is available. For that, a deep understanding of metabolic routes that support hepatic diseases is needed.

AREAS COVERED

This review covers aspects of the onset of NAFLD. Thereby, biochemistry routes as well as cellular and metabolic effects of the gut microbiota in body's homeostasis and epigenetics are contextualized.

EXPERT OPINION

Recently, the development of biological sciences has generated innovative knowledge, bringing new insights and perspectives to clarify the systems biology of liver diseases. A detailed comprehension of epigenetics mechanisms will offer possibilities to develop new therapeutic and diagnostic strategies for NAFLD. Different epigenetic processes have been reported that are modulated by the environment such as gut microbiota, suggesting strong interplays between cellular behavior and pathology. Thus, a more complete description of such mechanisms in hepatic diseases will help to clarify how to control the establishment of fatty liver, and precisely describe molecular interplays that potentially control NAFLD.

Targeting Akt-associated microRNAs for cancer therapeutics

The uncontrolled growth and spread of abnormal cells because of activating protooncogenes and/or inactivating tumor suppressor genes are the hallmarks of cancer. The PI3K/Akt signaling is one of the most frequently activated pathways in cancer cells responsible for the regulation of cell survival and proliferation in stress and hypoxic conditions during oncogenesis. Non-coding RNAs are a large family of RNAs that are not involved in protein-coding, and microRNAs (miRNAs) are a sub-set of non-coding RNAs with a single strand of 18-25 nucleotides. miRNAs are extensively involved in the post-transcriptional regulation of gene expression and play an extensive role in the regulatory mechanisms including cell differentiation, proliferation, apoptosis, and tumorigenesis. The impact of cancer on mRNA stability and translation efficiency is extensive and therefore, cancerous tissues exhibit drastic alterations in the expression of miRNAs. miRNAs can be modulated by utilizing techniques such as miRNA mimics, miRNA antagonists, or CRISPR/Cas9. In addition to their capacity as potential targets in cancer therapy, they can be used as reliable biomarkers to diagnose the disease at the earliest stage. Recent evidence indicates that microRNA-mediated gene regulation intersects with the Akt pathway, forming an Akt-microRNA regulatory network. miRNAs and Akt in this network operate together to exert their cellular tasks. In the current review, we discuss the Akt-associated miRNAs in several cancers, their molecular regulation, and how this newly emerging knowledge may contribute greatly to revolutionize cancer therapy.

Expression analysis of microRNAs and their target mRNAs of testes with high and low sperm motility in domestic pigeons (Columba livia)

Sperm motility is one of the most important indicators to evaluate poultry fertility. In order to explore key molecular regulation roles related to sperm motility, we employed testicular RNA sequencing of pigeon. A total of 705 known and 385 novel microRNAs were identified. Compared with the low sperm motility group, four upregulated and two downregulated miRNAs in the high sperm motility group were identified. A total of 3567 target mRNAs were predicted and four target mRNAs were selected to validate by qPCR. The miRNA-mRNA interaction network analysis, indicated that mmu-miR-183-5p /FOXO1 and PC-3p-244994_31/CHDH pairs might affect sperm motility. GO and KEGG annotation analysis showed that target genes of differentially expressed miRNAs were related to serine/threonine kinase activity, ATP binding, Wnt and MAPK signaling pathway. The study provided a global miRNAs transcriptome of pigeon and a novel insight into the expression of the miRNAs in testes that associated with sperm motility.

Neuroprotective effects of miR-331-3p through improved cell viability and inflammatory marker expression: Correlation of serum miR-331-3p levels with diagnosis and severity of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a common neurodegenerative disease with an increasing incidence rate. Numerous microRNAs (miRNAs) have been found to be involved in AD progression. This study aimed to investigate the expression and diagnostic value of microRNA-331-3p (miR-331-3p) in AD patients and to explore the effects of miR-331-3p on neuronal viability and neuroinflammation.

METHODS

This study recruited AD patients and used Aβ_1-40 treated SH-SY5Y cells mimicking AD characteristics. The expression of miR-331-3p was estimated using reverse transcription quantitative PCR. A receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic value of miR-331-3p, and the correlation of miR-331-3p with patients' Mini-Mental State Examination (MMSE) scores and serum proinflammatory cytokines were analyzed. The effects of miR-331-3p on neuronal viability and inflammatory response were explored in SH-SY5Y cells by in vitro analysis.

RESULTS

In AD patients and Aβ_1-40 treated SH-SY5Y cells, the expression of miR-331-3p was significantly downregulated. Serum miR-331-3p had certain diagnostic potential and was correlated with the MMSE scores and serum proinflammatory cytokine levels of AD patients. In Aβ_1-40-treated SH-SY5Y cells, the overexpression of miR-331-3p enhanced cell viability and inhibited inflammatory responses.

CONCLUSION

The data of this study indicated that serum expression of miR-331-3p is decreased in AD patients, and is correlated with the MMSE scores and proinflammatory cytokine levels of AD patients. In addition, miR-331-3p can regulate the cell viability and the expression of pro-inflammatory cytokines of Aβ_1-40 treated SH-SY5Y cells, indicating the potential neuroprotective role of miR-331-3p.

LINC00240 promotes gastric cancer cell proliferation, migration and EMT via the miR-124-3p / DNMT3B axis

Gastric cancer (GC) remains one of prevalent causes of cancer-related deaths worldwide. Long noncoding RNA is related to various cancers. Our study was conducted to explore the biological effects of LINC00240 on the tumorigenesis of GC and uncover its possible mechanisms. LINC00240 expression was determined in GC cell lines and samples through quantitative Real-time Polymerase Chain Reaction (qRT-PCR). The functional effects of LINC00240 were validated using in vitro and in vivo assays. Targets were assessed by AGO2-dependent RNA immunoprecipitation assay and dual-luciferase report assays. Our findings suggested higher LINC00240 expression in GC tissues and cells. Through downregulating LINC00240, cell proliferation, invasion and migration were retarded in vitro, and tumorigenesis of GC cells was notably suppressed in vivo. Further research showed that LINC00240 was a cytoplasmic lncRNA that shared miRNA response elements of microRNA (miR)-124-3p with DNMT3B, thus forming a LINC00240/miR-124-3p/DNMT3B axis explaining the functions of LINC00240. In a word, our study reveals that LINC00240 promotes GC tumorigenesis via a LINC00240/miR-124-3p/DNMT3B axis as an oncogene. These findings objectivise that LINC00240 may be a potential diagnostic biomarker for GC. SIGNIFICANCE OF THE STUDY: Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related death across the world. Then we analysed lncRNA microarray of GC and selected LINC00240 as the study object. Therefore, the potential molecular mechanism as well as physiological function of LINC00240 in GC was discussed. Then we reveal that LINC00240 acts as an oncogene in GC progression via the miR-99a-5p/IGF1R axis. This study is the first to demonstrate the roles of LINC00240 in GC.

MiR-485-3p serves as a biomarker and therapeutic target of Alzheimer's disease via regulating neuronal cell viability and neuroinflammation by targeting AKT3

BACKGROUND

Numerous microRNAs (miRNAs) have been identified as functional molecules in Alzheimer's disease (AD) pathogenesis. This study aimed to investigate the diagnostic value of microRNA-485-3p (miR-485-3p) in AD patients, evaluate the effect of miR-485-3p on neuronal viability and neuroinflammation, as well as the underlying molecular mechanisms.

METHODS

Quantitative Real-Time PCR was used to estimate expression of miR-485-3p and AKT3. A ROC analysis was used to evaluate the diagnostic value of miR-485-3p. The correlation of miR-485-3p with patients' MMSE score and inflammatory response was analyzed. Using Aβ-treated SH-SY5Y and BV2 cells models, the effects of miR-485-3p on neuronal proliferation, apoptosis, and neuroinflammation were explored. A luciferase reporter assay was used to confirm the target gene of miR-485-3p in both SH-SY5Y and BV2 cells.

RESULTS

Serum miR-485-3p expression was significantly upregulated in AD patients and cell models, which had a high diagnostic accuracy and correlated with MMSE score and inflammatory response in AD patients. The knockdown of miR-485-3p in SH-SY5Y and BV2 cells was found to significantly reverse the effect of Aβ treatment on neuronal viability and neuroinflammation. AKT3 was determined as a target of miR-485-3p, which might mediate the biological function of miR-485-3p in AD pathogenesis.

CONCLUSION

All the data indicated that increased serum miR-485-3p serves as a diagnostic biomarker in AD patients, and knockdown of miR-485-3p exerts a neuroprotective role by improving neuronal viability and weakening neuroinflammation, which may be mediated by AKT3. This study may provide a novel biomarker and therapeutic target for AD therapy.

Circ_0067835 sponges miR-324-5p to induce HMGA1 expression in endometrial carcinoma cells

Endometrial cancer is a common gynaecological malignant tumour among women across the world. Circular RNAs (circRNAs) are a novel kind of non‐coding RNAs, and they can play a crucial role in multiple cancers. Nevertheless, the mechanisms of circRNAs in regulating gene expression in endometrial cancer are still unclear. Here, our work sought to focus on the role that circ_0067835 exert in progression and development of endometrial cancer cells. We observed circ_0067835 was markedly elevated in endometrial cancer. Then, changes in endometrial cancer cell (RL95‐2 and HEC‐1B) function were determined after circ_0067835 knockdown. Loss‐of‐functional assays revealed that circ_0067835 down‐regulation significantly repressed RL95‐1 and HEC‐1B cell proliferation, migration and invasion. Bioinformatics analysis, luciferase reporter experiment and RNA pull‐down assay were employed to predict and validate circ_0067835 can bind to miR‐324‐5p. Increase in miR‐324‐5p remarkably depressed the proliferation, migration and invasion of endometrial cancer cells via inhibiting high mobility group A1 (HMGA1). HMGA1 is identified as a vital prognostic biomarker in endometrial cancer. Currently, we reported circ_0067835 was positively correlated with HMGA1 in endometrial cancer. We implied that circ_0067835 was capable of sponging miR‐324‐5p and inducing its downstream target HMGA1 in vitro and in vivo. In conclusion, circ_0067835 can compete with miR‐324‐5p, resulting in HMGA1 up‐regulation, and therefore induce the development of endometrial cancer.

Non-Coding RNAs as Sensors of Oxidative Stress in Neurodegenerative Diseases

Oxidative stress (OS) results from an imbalance between the production of reactive oxygen species and the cellular antioxidant capacity. OS plays a central role in neurodegenerative diseases, where the progressive accumulation of reactive oxygen species induces mitochondrial dysfunction, protein aggregation and inflammation. Regulatory non-protein-coding RNAs (ncRNAs) are essential transcriptional and post-transcriptional gene expression controllers, showing a highly regulated expression in space (cell types), time (developmental and ageing processes) and response to specific stimuli. These dynamic changes shape signaling pathways that are critical for the developmental processes of the nervous system and brain cell homeostasis. Diverse classes of ncRNAs have been involved in the cell response to OS and have been targeted in therapeutic designs. The perturbed expression of ncRNAs has been shown in human neurodegenerative diseases, with these changes contributing to pathogenic mechanisms, including OS and associated toxicity. In the present review, we summarize existing literature linking OS, neurodegeneration and ncRNA function. We provide evidences for the central role of OS in age-related neurodegenerative conditions, recapitulating the main types of regulatory ncRNAs with roles in the normal function of the nervous system and summarizing up-to-date information on ncRNA deregulation with a direct impact on OS associated with major neurodegenerative conditions.

Quercetin induces apoptosis in meningioma cells through the miR-197/IGFBP5 cascade

To investigate the effects of quercetin on cell viability and apoptosis in meningioma cells and to determine the underlying molecular mechanism. HBL-52 meningioma cells were treated with quercetin at doses of 1, 5, 10, 20, and 40 ng/mL for 24, 36 and 48 h, and cell viability was assessed using the Cell Counting kit-8 (CCK-8) test. Apoptosis was determined by flow cytometry. Bax, Bcl-2, and IGFBP5 protein expression was assessed by western blot, and IGFBP5 and miR-197 mRNA levels were measured using quantitative reverse transcription PCR (qRT-PCR). The interaction between miR-197 and IGFBP5 was verified by dual luciferase assay. Quercetin reduces viability and proliferation and increases apoptosis in HBL-52 cells in a dose- and time-dependent manner. Quercetin treatment also decreases Bcl-2 and increases Bax protein expression, and increases miR-197 mRNA while reducing IGFBP5 mRNA expression. A dual luciferase assay showed that miR-197 interacts directly with binding sites in the 3'untranslated region of IGFBP5, and that miR-197 overexpression reduced IGFBP5 expression. Quercetin may reduce meningioma cell proliferation and increase apoptosis by activating the miR-197/IGFBP5 cascade and regulating Bcl-2/Bax.

Upregulation of miR-361-3p suppresses serotonin-induced proliferation in human pulmonary artery smooth muscle cells by targeting SERT

Background

Abnormal proliferation of pulmonary artery smooth muscle cells (PASMCs) is a key mechanism in pulmonary arterial hypertension (PAH). Serotonin (5-hydroxytryptamine, 5-HT) can induce abnormal proliferation of PASMCs. The role of miR-361-3p in serotonin-induced abnormal PASMCs proliferation remains unclear.

Methods

The miR-361-3p level was analyzed in plasma from PAH patients and normal controls and in human PASMCs (hPASMCs) using RT-PCR. The hPASMCs were transfected with an miR-361-3p mimic and then treated with serotonin. Untransfected hPASMCs were used as the control. Cell proliferation was evaluated using an MTS assay and 5-ethynyl-2′-deoxyuridine (EdU) staining. The cell cycle stages were evaluated using flow cytometry. The association between miR-361-3p and serotonin transporter (SERT) was determined using a luciferase reporter assay and anti-AGO2 RNA immunoprecipitation assay. The protein expression was evaluated via western blotting.

Results

The miR-361-3p level was lower in plasma from PAH patients than in plasma from the any of the normal control subjects. The mean pulmonary arterial pressure, pulmonary vascular resistance and pulmonary vascular resistance index were higher in PAH patients whose miR-361-3p level was lower than the median value for patients than in those whose miR-361-3p level was higher than the median. Serotonin treatment reduced miR-361-3p expression in the hPASMCs. MiR-361-3p overexpression suppressed cell proliferation, promoted apoptosis, induced G1 arrest, and decreased the phosphorylation level of ERK1/2 in serotonin-treated hPASMCs. SERT was identified as an miR-361-3p target. Its overexpression alleviated the effect of miR-361-3p overexpression on serotonin-induced hPASMC proliferation and upregulation of phosphorylated ERK1/2.

Conclusions

The miR-361-3p level is lower in the plasma of PAH patients. Upregulation of miR-361-3p suppresses serotonin-induced proliferation of hPASMCs by targeting SERT. Our results suggest that miR-361-3p is a potential therapeutic target in PAH.

Regulation of ABO blood group antigen expression by miR-331-3p and miR-1908-5p during hematopoietic stem cell differentiation

The ABO blood group system is the most important factor in clinical transfusion medicine and is implicated in a number of human diseases. ABO antigens are not confined to red blood cells (RBCs) and are widely expressed in a variety of human cells and tissues. To date, many alleles with variant ABO expression have been identified and in many cases traced to one of the >250 reported genetic variations in the respective glycosyltransferase. The role of microRNAs (miRNAs) in the regulation of blood group antigens during erythropoiesis has not been addressed, however. Here, we show that miR-331-3p and miR-1908-5p directly target the mRNA of glycosyltransferases A and B. Expression levels of miR-331-3p and miR-1908-5p inversely correlated with levels of blood group A antigen. In addition, we found that overexpression of these miRNAs in hematopoietic stem cells led to a significantly reduced number of blood group A antigens per RBC. Simultaneous targeting of the transcription factor (TF) SP1 by miR-331-3p further enhanced these effects. The targeting rendered SP1 incapable of binding to the ABO gene promoter, causing further downregulation of blood group A antigen expression by up to 70%. Taken together, expression changes in these miRNAs may account for rare cases of weak A/B phenotypes that genetic variations in the glycosyltransferase coding region cannot explain. These results also suggest an explanation for the disappearance of ABH antigens during carcinogenesis and point to new therapeutic targets in ABO mismatched organ transplantation.

MicroRNA-518-3p suppresses cell proliferation, invasiveness, and migration in colorectal cancer via targeting TRIP4

MicroRNA (miR)-518-3p has been shown to function as a tumor suppressor. This study was conducted to investigate the effects of miR-518-3p in colorectal cancer (CRC). The miR-518-3p mimic, mimic negative control (NC), miR-518-3p inhibitor, inhibitor-NC, ShRNA-TRIP4, and ShRNA-NC vectors were transfected into SW480 cells using Lipofectamine 2000. Cell viability was detected using CCK-8. Colony formation, cell invasiveness, and cell migration were assessed by plate colony formation, Transwell assays, and wound healing assays, respectively. Relative mRNA and protein levels were detected using RT-qPCR and Western blot, respectively. The target gene thyroid hormone receptor interactor 4 (TRIP4) of miR-518-3p was identified and further verified using dual-luciferase reporter assay. Compared with normal tissues, levels of miR-518-3p were decreased and TRIP4 was significantly increased in the tissues from patients with CRC. Following transfection with a miR-518-3p mimic or ShRNA-TRIP4, cell viability decreased in a time-dependent manner, and colony formation rate, wound closure rate, and the number of invasive cells were much lower for the transfected cells than in the corresponding NC and control groups. miR-518-3p overexpression or silencing of TRIP4 significantly down-regulated the expression of MMP-2 and MMP-9. Knockdown of miR-518-3p had the opposite effects, and TRIP4 was identified as a target of miR-518-3p. The inhibitory effects of miR-518-3p on the progressions of CRC are associated with TRIP4.

Epigenetic control of exercise adaptations in the equine athlete: Current evidence and future directions

Horses (Equus ferus caballus) have evolved over the past 300 years in response to man-made selection for particular athletic traits. Some of the selected traits were selected based on the size and horses' muscular power (eg Clydesdales), whereas other breeds were bred for peak running performance (eg Thoroughbred and Arabian). Although the physiological changes and some of the cellular adaptations responsible for athletic potential of horses have been identified, the molecular mechanisms are only just beginning to be comprehensively investigated. The purpose of this review was to outline and discuss the current understanding of the molecular mechanisms underpinning the athletic performance and cardiorespiratory fitness in athletic breeds of horses. A brief review of the biology of epigenetics is provided, including discussion on DNA methylation, histone modifications and small RNAs, followed by a summary and critical review of the current work on the exercise-induced epigenetic and transcriptional changes in horses. Important unanswered questions and currently unexplored areas that deserve attention are highlighted. Finally, a rationale for the analysis of epigenetic modifications in the context with exercise-related traits and ailments associated with athletic breeds of horses is outlined in order to help guide future research.

Differentially expressed lncRNA-m433s1 regulates FSH secretion by functioning as a miRNA sponge in male rat anterior pituitary cells†

Long noncoding RNAs (lncRNAs) are important regulators that have multiple functions in a variety of biological processes. However, the contributions of lncRNAs to follicle-stimulating hormone (FSH) secretion remain largely unknown. In this study, we first identified a novel lncRNA, lncRNA-m433s1, as an intergenic lncRNA located in the cytoplasm. We next used MS2-RIP assays to demonstrate that lncRNA-m433s1 interacted with miR-433. Furthermore, we detected the levels of lncRNA-m433s1, miR-433, and Fshβ expression, FSH concentrations, and apoptosis upon overexpression and knockdown of lncRNA-m433s1, revealing that lncRNA-m433s1 upregulated Fshβ expression. Globally, lncRNA-m433s1 reduced the inhibitory effect of miR-433 on Fshβ and further regulated FSH secretion as a competing endogenous RNA (ceRNA) by sponging miR-433. This ceRNA model will provide novel insight into the regulatory mechanisms of lncRNAs associated with rat reproduction.

MicroRNA-146a downregulates the production of hyaluronic acid and collagen I in Graves' ophthalmopathy orbital fibroblasts

The present study aimed to investigate the effect of microRNA (miR)-146a on the secretion of hyaluronic acid (HA) and collagen I in Graves' ophthalmopathy (GO) orbital fibroblasts, and identify potential novel targets for the clinical treatment of GO. Orbital fibroblasts were extracted from orbital connective tissue, and primary cells were identified via immunohistochemistry. The levels of HA and collagen I in orbital fibroblasts of non-GO controls and patients with GO were examined via reverse transcription-quantitative PCR (RT-qPCR). miR-146a was overexpressed or inhibited in primary orbital fibroblasts via lentiviral infection, and the levels of HA and collagen I following miR-146a overexpression or inhibition were detected via ELISA and RT-qPCR. The results indicated that the mRNA expression of HA and collagen I was higher in orbital fibroblasts from patients with GO compared with the non-GO cohort. Overexpression of miR-146a reduced, and inhibition of miR-146a increased the production of HA and collagen I in GO orbital fibroblasts. In conclusion, it was demonstrated that miR-146a downregulated the secretion of HA and collagen I in GO orbital fibroblasts in vitro, which may affect glycosaminoglycan aggregation and collagen deposition in GO.

Overexpression of miR-144-3p alleviates polycystic ovaries syndrome through targeting expression of HSP-70

Increasing microRNAs are shown to be participate in polycystic ovarian syndrome (PCOS) pathogenesis. Nevertheless, the biological effects of miR-144-3p and its detailed mechanisms in PCOS are to be investigated. The purpose of our work was to study the function of miR-144-3p in PCOS. Currently, Expression of miR-144-3p was greatly reduced in PCOS patients and PCOS rat models. In addition, HSP-70 expression was greatly elevated PCOS. Cell proliferation assays and flow cytometry assay were carried out following the overexpression of miR-144-3p in ovarian granulosa cells from PCOS rat models. We observed that miR-144-3p overexpression induced the proliferation and repressed cell apoptosis while loss of miR-144-3p demonstrated an opposite process. Then, PCOS rat models were classified to four groups: LV-NC group, LV-miR-144-3p group, Anti-control group, and Anti-miR-144-3p group. In response to loss of miR-144-3p, we found E2, T, and LH serum levels were elevated and FSH serum level was inhibited. Upregulation of miR-144-3p exhibited an opposite process. Moreover, HSP-70 was a direct target of miR-144-3p. Furthermore, increased expression of HSP-70 rescued the effects of miR-144-3p on ovarian granulosa cell growth and apoptosis. In addition, knockdown of HSP-70 alleviated endocrine disorders and abnormal ovarian weight in vivo. To sum up, miR-144-3p might function as a novel target for PCOS treatment via targeting HSP-70.

Parallel analysis of miRNAs and mRNAs suggests distinct regulatory networks in Crassostrea gigas infected by Ostreid herpesvirus 1

Background

Since 2008, the aquaculture production of Crassostrea gigas was heavily affected by mass mortalities associated to Ostreid herpesvirus 1 (OsHV-1) microvariants worldwide. Transcriptomic studies revealed the major antiviral pathways of the oyster immune response while other findings suggested that also small non-coding RNAs (sncRNA) such as microRNAs might act as key regulators of the oyster response against OsHV-1. To explore the explicit connection between small non-coding and protein-coding transcripts, we performed paired whole transcriptome analysis of sncRNA and messenger RNA (mRNA) in six oysters selected for different intensities of OsHV-1 infection.

Results

The mRNA profiles of the naturally infected oysters were mostly governed by the transcriptional activity of OsHV-1, with several differentially expressed genes mapping to the interferon, toll, apoptosis, and pro-PO pathways. In contrast, miRNA profiles suggested more complex regulatory mechanisms, with 15 differentially expressed miRNAs (DE-miRNA) pointing to a possible modulation of the host response during OsHV-1 infection. We predicted 68 interactions between DE-miRNAs and oyster 3′-UTRs, but only few of them involved antiviral genes. The sncRNA reads assigned to OsHV-1 rather resembled mRNA degradation products, suggesting the absence of genuine viral miRNAs.

Conclusions

We provided data describing the miRNAome during OsHV-1 infection in C. gigas. This information can be used to understand the role of miRNAs in healthy and diseased oysters, to identify new targets for functional studies and, eventually to disentangle cause and effect relationships during viral infections in marine mollusks.

Diazoxide Protects against Myocardial Ischemia/Reperfusion Injury by Moderating ERS via Regulation of the miR-10a/IRE1 Pathway

Nowadays, reperfusion is still the most effective treatment for ischemic heart disease. However, cardiac reperfusion therapy would lead to reperfusion injury, which may have resulted from endoplasmic reticulum stress (ERS) during reperfusion. Diazoxide (DZ) is a highly selective mitochondrial adenosine triphosphate-sensitive potassium channel opener. Its protective effect on I/R injury has been confirmed in many organs such as the heart and brain. However, the mechanism of its protective effect has not been fully elucidated. MicroRNAs (miRNAs) are widely involved in pathologies of heart disease. In this study, we found that miR-10a expression was highly upregulated in the myocardial I/R groups, and DZ treatment significantly reduced the expression of miR-10a. More importantly, we found that DZ treatment can moderate ERS via regulation of the miR-10a/IRE1 pathway in the I/R and H/R models, thereby protecting myocardial H/R injury.

MicroRNA-200b is a potential biomarker of the expression of PD-L1 in patients with lung cancer

BACKGROUND

Advanced non-small cell lung cancer (NSCLC) has a high mortality rate and poor prognosis. However, outcomes have gradually improved after the introduction of novel immunotherapies, including immune checkpoint inhibitors (ICIs). Although programmed death-ligand 1 (PD-L1) expression in tumor tissues is a known biomarker for guiding ICI treatment of NSCLC, challenges such as difficulty of liquid biopsy and heterogeneous results during treatment persist. This study evaluated the potential of miR200b as a surrogate biomarker for PD-L1 expression.

METHODS

We used the human lung cancer cell lines H226, H460, H520, A549, and H1975. miR200b expression in blood and bronchoscopy specimens of NSCLC patients was evaluated using reverse-transcription-quantitative PCR. Using flow cytometry, PD-L1 expression in vitro, as well as in tumor tissues, was evaluated after transfection with a mimic miR200b or siRNA.

RESULTS

miR200b expression negatively correlated with PD-L1 expression in all cell lines. The induction or knockdown of miR200b also altered PD-L1 expression in vitro. The patient group with a PD-L1 tumor proportion score ≥ 50% had significantly lower miR200b expression in the bronchoscopy specimens (P = 0.025) and serum-derived exosomes (P = 0.022) than that with PD-L1 tumor proportion score < 50%.

CONCLUSIONS

miR200b can regulate PD-L1 expression in lung cancer cells, and miR200b expression in clinical specimens negatively correlated with PD-L1 expression. Thus, miR200b may be a useful surrogate biomarker for PD-L1 expression in lung cancer patients.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: High PD-L1 expression was linked to low miR200b expression, whereas low PD-L1 expression was linked to high miR200b expression in human lung cancer patients. Thus, miR200b overexpression or silencing can control PD-L1 expression in cancer cells. What this study adds We demonstrated the potential of miR200b as a surrogate biomarker for PD-L1 expression in lung cancer patients.

Genetically Encoded Reporter Genes for MicroRNA Imaging in Living Cells and Animals

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by base paring with the complementary sequences of the target mRNAs, and then exert their function through degrading mRNA or inhibiting protein translation. They play a significant role as a regulatory factor in biological processes of organism development, cell proliferation, differentiation, and cell death. Some of the traditional methods for studying miRNAs, such as northern blot, real-time PCR, or microarray, have been extensively used to investigate the biological properties and expression patterns of miRNAs. However, these methods often require considerable time, cell samples, and the design of effective primers or specific probes. Therefore, in order to gain a deeper understanding of the role of miRNAs in biological processes and accelerate the clinical application of miRNAs in the field of disease treatment, non-invasive, sensitive, and efficient imaging methods are needed to visualize the dynamic expression of miRNAs in living cells and animals. In this study, we reviewed the recent progress in the genetically encoded reporter genes for miRNA imaging.

The effect of oleuropein on apoptotic pathway regulators in breast cancer cells

In spite of advancements in breast cancer therapy, this disease is still one of the significant causes of women fatalities globally. Dysregulation of miRNA plays a pivotal role in the initiation and progression of cancer. Therefore, the administration of herbal compounds with anticancer effects through controlling microRNA expression can be considered as a promising therapy for cancer. Oleuropein is the most prevalent phenolic compound in olive. Given its domestic consumption, low cost, and nontoxicity for human beings, oleuropein can be used in combination with the standard chemotherapy drugs. To this end, we examined the effect of oleuropein on two breast cancer cell lines (MCF7 and MDA-MB-231). Our findings revealed that oleuropein significantly decreased cell viability in a dose- and time-dependent manner, while it increased the apoptosis in MCF7 and MDA-MB-231 cells. In the presence of oleuropein, the expression levels of miR-125b, miR-16, miR-34a, p53, p21, and TNFRS10B increased, while that of bcl-2, mcl1, miR-221, miR-29a and miR-21 decreased. The findings pointed out that oeluropein may induce apoptosis via not only increasing the expression of pro-apoptotic genes and tumor suppressor miRNAs, but also decreasing the expression of anti-apoptotic genes and oncomiR. Consequently, oleuropein can be regarded as a suitable herbal medication for cancer therapy.

Changes in MicroRNA Expression during Rabbit Hemorrhagic Disease Virus (RHDV) Infection

Current knowledge on the role of microRNAs (miRNAs) in rabbit hemorrhagic disease virus (RHDV) infection and the pathogenesis of rabbit hemorrhagic disease (RHD) is still limited. RHDV replicates in the liver, causing hepatic necrosis and liver failure. MiRNAs are a class of short RNA molecules, and their expression profiles vary over the course of diseases, both in the tissue environment and in the bloodstream. This paper evaluates the expression of miRNAs in the liver tissue (ocu-miR-122-5p, ocu-miR-155-5p, and ocu-miR-16b-5p) and serum (ocu-miR-122-5p) of rabbits experimentally infected with RHDV. The expression levels of ocu-miR-122-5p, ocu-miR-155-5p, and ocu-miR-16b-5p in liver tissue were determined using reverse transcription quantitative real-time PCR (RT-qPCR), and the expression level of circulating ocu-miR-122-5p was established using droplet digital PCR (ddPCR). The expression levels of ocu-miR-155-5p and ocu-miR-16b-5p were significantly higher in the infected rabbits compared to the healthy rabbits (a fold-change of 5.8 and 2.5, respectively). The expression of ocu-miR-122-5p was not significantly different in the liver tissue from the infected rabbits compared to the healthy rabbits (p = 0.990), while the absolute expression level of the circulating ocu-miR-122-5p was significantly higher in the infected rabbits than in the healthy rabbits (p < 0.0001). Furthermore, a functional analysis showed that ocu-miR-155-5p, ocu-miR-16b-5p, and ocu-miR-122-5p can regulate the expression of genes involved in processes correlated with acute liver failure (ALF) in rabbits. Search tool for the retrieval of interacting genes/proteins (STRING) analysis showed that the potential target genes of the three selected miRNAs may interact with each other in different pathways. The results indicate the roles of these miRNAs in RHDV infection and over the course of RHD and may reflect hepatic inflammation and impairment/dysfunction in RHD.

Impact of Anticoagulation and Sample Processing on the Quantification of Human Blood-Derived microRNA Signatures

Blood-derived microRNA signatures have emerged as powerful biomarkers for predicting and diagnosing cardiovascular disease, cancer, and metabolic disorders. Platelets and platelet-derived microvesicles are a major source of microRNAs. We have previously shown that the inappropriate anticoagulation and storage of blood samples causes substantial platelet activation that is associated with the release of platelet-stored molecules into the plasma. However, it is currently unclear if circulating microRNA levels are affected by artificial platelet activation due to suboptimal plasma preparation. To address this issue, we used a standardized RT-qPCR test for 12 microRNAs (thrombomiR^®, TAmiRNA GmbH, Vienna, Austria) that have been associated with cardiovascular and thrombotic diseases and were detected in platelets and/other hematopoietic cells. Blood was prevented from coagulating with citrate–theophylline–adenosine–dipyridamole (CTAD), sodium citrate, or ethylenediaminetetraacetic acid (EDTA) and stored for different time periods either at room temperature or at 4 °C prior to plasma preparation and the subsequent quantification of microRNAs. We found that five microRNAs (miR-191-5p, miR-320a, miR-21-5p, miR-23a-3p, and miR-451a) were significantly increased in the EDTA plasma. Moreover, we observed a time-dependent increase in plasma microRNAs that was most pronounced in the EDTA blood stored at room temperature for 24 h. Furthermore, significant correlations between microRNA levels and plasma concentrations of platelet-stored molecules pointed towards in vitro platelet activation. Therefore, we strongly recommend to (i) use CTAD as an anticoagulant, (ii) process blood samples as quickly as possible, and (iii) store blood samples at 4 °C whenever immediate plasma preparation is not feasible to generate reliable data on blood-derived microRNA signatures.

Molecular profiling demonstrates modulation of immune cell function and matrix remodeling during luteal rescue†

The corpus luteum (CL) is essential for maintenance of pregnancy in all mammals and luteal rescue, which occurs around day 16-19 in the cow, is necessary to maintain luteal progesterone production. Transcriptomic and proteomic profiling were performed to compare the day 17 bovine CL of the estrous cycle and pregnancy. Among mRNA and proteins measured, 140 differentially abundant mRNA and 24 differentially abundant proteins were identified. Pathway analysis was performed using four programs. Modulated pathways included T cell receptor signaling, vascular stability, cytokine signaling, and extracellular matrix remodeling. Two mRNA that were less in pregnancy were regulated by prostaglandin F2A in culture, while two mRNA that were greater in pregnancy were regulated by interferon tau. To identify mRNA that could be critical regulators of luteal fate, the mRNA that were differentially abundant during early pregnancy were compared to mRNA that were differentially abundant during luteal regression. Eight mRNA were common to both datasets, including mRNA related to regulation of steroidogenesis and gene transcription. A subset of differentially abundant mRNA and proteins, including those associated with extracellular matrix functions, were predicted targets of differentially abundant microRNA (miRNA). Integration of miRNA and protein data, using miRPath, revealed pathways such as extracellular matrix-receptor interactions, abundance of glutathione, and cellular metabolism and energy balance. Overall, this study has provided a comprehensive profile of molecular changes in the corpus luteum during maternal recognition of pregnancy and has indicated that some of these functions may be miRNA-regulated.

Non-Coding RNAs and Nucleosome Remodeling Complexes: An Intricate Regulatory Relationship

Eukaryotic genomes are pervasively transcribed, producing both coding and non-coding RNAs (ncRNAs). ncRNAs are diverse and a critical family of biological molecules, yet much remains unknown regarding their functions and mechanisms of regulation. ATP-dependent nucleosome remodeling complexes, in modifying chromatin structure, play an important role in transcriptional regulation. Recent findings show that ncRNAs regulate nucleosome remodeler activities at many levels and that ncRNAs are regulatory targets of nucleosome remodelers. Further, a series of recent screens indicate this network of regulatory interactions is more expansive than previously appreciated. Here, we discuss currently described regulatory interactions between ncRNAs and nucleosome remodelers and contextualize their biological functions.

Fecal microRNAs as Innovative Biomarkers of Intestinal Diseases and Effective Players in Host-Microbiome Interactions

Over the past decade, short non-coding microRNAs (miRNAs), including circulating and fecal miRNAs have emerged as important modulators of various cellular processes by regulating the expression of target genes. Recent studies revealed the role of miRNAs as powerful biomarkers in disease diagnosis and for the development of innovative therapeutic applications in several human conditions, including intestinal diseases. In this review, we explored the literature and summarized the role of identified dysregulated fecal miRNAs in intestinal diseases, with particular focus on colorectal cancer (CRC) and celiac disease (CD). The aim of this review is to highlight one fascinating aspect of fecal miRNA function related to gut microbiota shaping and bacterial metabolism influencing. The role of miRNAs as “messenger” molecules for inter kingdom communications will be analyzed to highlight their role in the complex host-bacteria interactions. Moreover, whether fecal miRNAs could open up new perspectives to develop novel suitable biomarkers for disease detection and innovative therapeutic approaches to restore microbiota balance will be discussed.

Liquid biopsy markers for stroke diagnosis

INTRODUCTION

There is a short time window (4.5 h) for the effective treatment of acute ischemic stroke (AIS), which uses recombinant tissue plasminogen activator (rt-PA). Unfortunately, this short therapeutic timeframe is a contributing factor to the relatively small number of patients (~7%) that receive rt-PA. While neuroimaging is the major diagnostic for AIS, more timely decisions could be made using a molecular diagnostic.

AREAS COVERED

In this review, we survey neuroimaging techniques used to diagnose stroke and their limitations. We also highlight the potential of various molecular/cellular biomarkers, especially peripheral blood-based (i.e. liquid biopsy) biomarkers, for diagnosing stroke to allow for precision decisions on managing stroke in a timely manner. Both protein and nucleic acid molecular biomarkers are reviewed. In particular, mRNA markers are discussed for AIS and hemorrhagic stroke diagnosis sourced from both cells and extracellular vesicles.

EXPERT OPINION

While there are a plethora of molecular markers for stroke diagnosis that have been reported, they have yet to be FDA-cleared. Possible reasons include the inability for these markers to appear in sufficient quantities for highly sensitive clinical decisions within the rt-PA therapeutic time.

The Role of microRNAs in Organismal and Skin Aging

The aging process starts directly after birth and lasts for the entire lifespan; it manifests itself with a decline in an organism’s ability to adapt and is linked to the development of age-related diseases that eventually lead to premature death. This review aims to explore how microRNAs (miRNAs) are involved in skin functioning and aging. Recent evidence has suggested that miRNAs regulate all aspects of cutaneous biogenesis, functionality, and aging. It has been noted that some miRNAs were down-regulated in long-lived individuals, such as let-7, miR-17, and miR-34 (known as longevity-related miRNAs). They are conserved in humans and presumably promote lifespan prolongation; conversely, they are up-regulated in age-related diseases, like cancers. The analysis of the age-associated cutaneous miRNAs revealed the increased expression of miR-130, miR-138, and miR-181a/b in keratinocytes during replicative senescence. These miRNAs affected cell proliferation pathways via targeting the p63 and Sirtuin 1 mRNAs. Notably, miR-181a was also implicated in skin immunosenescence, represented by the Langerhans cells. Dermal fibroblasts also expressed increased the levels of the biomarkers of aging that affect telomere maintenance and all phases of the cellular life cycle, such as let-7, miR-23a-3p, 34a-5p, miR-125a, miR-181a-5p, and miR-221/222-3p. Among them, the miR-34 family, stimulated by ultraviolet B irradiation, deteriorates collagen in the extracellular matrix due to the activation of the matrix metalloproteinases and thereby potentiates wrinkle formation. In addition to the pro-aging effects of miRNAs, the plausible antiaging activity of miR-146a that antagonized the UVA-induced inhibition of proliferation and suppressed aging-related genes (e.g., p21WAF-1, p16, and p53) through targeting Smad4 has also been noticed. Nevertheless, the role of miRNAs in skin aging is still not fully elucidated and needs to be further discovered and explained.

Long Noncoding RNA HNF1A-AS1 Regulates Osteosarcoma Advancement Through Modulating the miR-32-5p/HMGB1 Axis

Background: Osteosarcoma (OS) is a primary malignant tumor in children and adolescents. Long noncoding RNA HNF1A antisense RNA 1 (HNF1A-AS1) is connected with OS development. However, there are few reports on the role and mechanism of HNF1A-AS1 in OS. Materials and Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to assess the expression of HNF1A-AS1, miR-32-5p, and high-mobility group protein B1 (HMGB1). Western blot analysis was performed to detect the protein level of HMGB1. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, transwell, or flow cytometer assays were applied to determine the proliferation, migration, invasion, and apoptosis of OS cells. The interaction between HNF1A-AS1 and miR-32-5p or HMGB1 was predicted by the starBase database and confirmed by dual-luciferase reporter assay. Enzyme-linked immunosorbent assay was employed to analyze levels of HMGB1 in the OS cell supernatant. Results: HNF1A-AS1 and HMGB1 were upregulated, while miR-32-5p was downregulated, in OS tissues and cells. Functionally, HNF1A-AS1 depletion induced apoptosis and impeded proliferation, migration, and invasion of OS cells. Interestingly, HNF1A-AS1 bound to miR-32-5p to regulate the expression of HMGB1. Furthermore, miR-32-5p knockdown overturned the effects of HNF1A-AS1 knockdown on apoptosis, proliferation, migration, and invasion of OS cells. In addition, the effects of HNF1A-AS1 silencing on the malignant behaviors of OS cells were reserved by HMGB1 overexpression. In addition, HNF1A-AS1 regulated the HMGB1 level in the OS cell supernatant through the miR-32-5p/HMGB1 axis. Conclusion: Downregulation of HNF1A-AS1 blocked OS progression through the miR-32-5p/HMGB1 axis, which provides a possible target and prognostic biomarker for treatment of OS.