Burkholderia pseudomallei-derived miR-3473 enhances NF-κB via targeting TRAF3 and is associated with different inflammatory responses compared to Burkholderia thailandensis in murine macrophages

Exploring the regulatory role of small RNAs in modulating host-pathogen interactions: implications for bacterial and viral infections

MicroRNAs (miRNAs) and transfer RNA-derived stress-induced RNAs (tiRNAs) have emerged as crucial players in the post-transcriptional regulation of gene expression in various cellular processes, including immunity and host defense against infections. In recent years, increasing evidence has highlighted their complex role in influencing the host response during viral and bacterial infections. miRNAs have been shown to play multiple roles in host-pathogen interaction like TLR activation and altered disease virulence during bacterial infections. In the context of viral infections, miRNAs are involved in regulating viral replication, pathogenesis, and immune evasion. Similarly, tiRNAs have recently emerged as novel players in bacterial and viral infections such as modulating bacterial growth, adaptation to stress conditions, host antiviral responses, and impacting viral replication and pathogenesis. This review provides a comprehensive analysis of the potential of miRNA expression profiles as diagnostic biomarkers to differentiate between bacterial and viral infections. Further discusses the key pathways through which small RNAs regulate bacterial and viral infection-related diseases.

Harnessing miRNAs: A Novel Approach to Diagnosis and Treatment of Tuberculosis

Mycobacterium tuberculosis (Mtb) complex, responsible for tuberculosis (TB) infection, continues to be a predominant global cause of mortality due to intricate host-pathogen interactions that affect disease progression. MicroRNAs (miRNAs), essential posttranscriptional regulators, have become pivotal modulators of these relationships. Recent findings indicate that miRNAs actively regulate immunological responses to Mtb complex by modulating autophagy, apoptosis, and immune cell activities. This has resulted in increased interest in miRNAs as prospective diagnostic indicators for TB, especially in differentiating active infection from latent or inactive stages. Variations in miRNA expression during Mtb infection indicate disease progression and offer insights into the immune response. Furthermore, miRNAs present potential as therapeutic targets in host-directed therapy (HDT) techniques for TB infection. This work examines the function of miRNAs in TB pathogenesis, with the objective of identifying particular miRNAs that regulate the immune response to the Mtb complex, evaluating their diagnostic value and exploring their therapeutic implications in host-directed therapy for TB infection. The objective is to enhance comprehension of how miRNAs can facilitate improved diagnosis and treatment of TB.

The ability of microRNAs to regulate the immune response in ischemia/reperfusion inflammatory pathways

MicroRNAs play a crucial role in regulating the immune responses induced by ischemia/reperfusion injury. Through their ability to modulate gene expression, microRNAs adjust immune responses by targeting specific genes and signaling pathways. This review focuses on the impact of microRNAs on the inflammatory pathways triggered during ischemia/reperfusion injury and highlights their ability to modulate inflammation, playing a critical role in the pathophysiology of ischemia/reperfusion injury. Dysregulated expression of microRNAs contributes to the pathogenesis of ischemia/reperfusion injury, therefore targeting specific microRNAs offers an opportunity to restore immune homeostasis and improve patient outcomes. Understanding the complex network of immunoregulatory microRNAs could provide novel therapeutic interventions aimed at attenuating excessive inflammation and preserving tissue integrity.

MicroRNA expression analysis in peripheral blood and soft-tissue of patients with periprosthetic hip infection

Aims

Current diagnostic tools are not always able to effectively identify periprosthetic joint infections (PJIs). Recent studies suggest that circulating microRNAs (miRNAs) undergo changes under pathological conditions such as infection. The aim of this study was to analyze miRNA expression in hip arthroplasty PJI patients.

Methods

This was a prospective pilot study, including 24 patients divided into three groups, with eight patients each undergoing revision of their hip arthroplasty due to aseptic reasons, and low- and high-grade PJI, respectively. The number of intraoperative samples and the incidence of positive cultures were recorded for each patient. Additionally, venous blood samples and periarticular tissue samples were collected from each patient to determine miRNA expressions between the groups. MiRNA screening was performed by small RNA-sequencing using the miRNA next generation sequencing (NGS) discovery (miND) pipeline.

Results

Overall, several miRNAs in plasma and tissue were identified to be progressively deregulated according to ongoing PJI. When comparing the plasma samples, patients with a high-grade infection showed significantly higher expression levels for hsa-miR-21-3p, hsa-miR-1290, and hsa-miR-4488, and lower expression levels for hsa-miR-130a-3p and hsa-miR-451a compared to the aseptic group. Furthermore, the high-grade group showed a significantly higher regulated expression level of hsa-miR-1260a and lower expression levels for hsa-miR-26a-5p, hsa-miR-26b-5p, hsa-miR-148b-5p, hsa-miR-301a-3p, hsa-miR-451a, and hsa-miR-454-3p compared to the low-grade group. No significant differences were found between the low-grade and aseptic groups. When comparing the tissue samples, the high-grade group showed significantly higher expression levels for 23 different miRNAs and lower expression levels for hsa-miR-2110 and hsa-miR-3200-3p compared to the aseptic group. No significant differences were found in miRNA expression between the high- and low-grade groups, as well as between the low-grade and aseptic groups.

Conclusion

With this prospective pilot study, we were able to identify a circulating miRNA signature correlating with high-grade PJI compared to aseptic patients undergoing hip arthroplasty revision. Our data contribute to establishing miRNA signatures as potential novel diagnostic and prognostic biomarkers for PJI.

Glycometabolism change during Burkholderia pseudomallei infection in RAW264.7 cells by proteomic analysis

Burkholderia pseudomallei is a Gram-negative intracellular bacterium that causes melioidosis, a life-threatening disease. The interaction of B. pseudomallei with its host is complicated, and cellular response to B. pseudomallei infection is still largely unknown. In this study, we aimed to determine host-cell responses to B. pseudomallei at the proteomics level. We performed proteomic profiling of B. pseudomallei HNBP001-infected mouse macrophage RAW264.7 cells to characterize the cellular response dynamics during infection. Western blot analysis was utilized for the validation of changes in protein expression. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted using the clusterProfiler R package. Compared with the negative control (NC) group, 811 common proteins varied over time, with a cut-off level of two fold change and an adjusted P-value less than 0.05. The bioinformatics analysis revealed that the proteins significantly changed in the B. pseudomallei HNBP001 infection group (Bp group) were enriched in glycometabolism pathways, including glycolysis, fructose and mannose metabolism, pentose phosphate pathway, galactose metabolism, and carbon metabolism. Western blot analysis verified three selected proteins involved in glycometabolism pathways, namely PGM1, PKM, and PGK1 were increase over time post the infection. Furthermore, in vitro functional analysis revealed an increased glucose uptake and decreased ATP production and O-GlcNAcylation in the Bp group compared with control group, suggesting that B. pseudomallei HNBP001 infection induces changes in glycometabolism in RAW264.7 cells. These results indicate that glycometabolism pathways change in RAW264.7 cells post B. pseudomallei HNBP001 infection, providing important insights into the intimate interaction between B. pseudomallei and macrophages.

microRNAs associated with the pathogenesis and their role in regulating various signaling pathways during Mycobacterium tuberculosis infection

Despite more than a decade of active study, tuberculosis (TB) remains a serious health concern across the world, and it is still the biggest cause of mortality in the human population. Pathogenic bacteria recognize host-induced responses and adapt to those hostile circumstances. This high level of adaptability necessitates a strong regulation of bacterial metabolic characteristics. Furthermore, the immune reponse of the host virulence factors such as host invasion, colonization, and survival must be properly coordinated by the pathogen. This can only be accomplished by close synchronization of gene expression. Understanding the molecular characteristics of mycobacterial pathogenesis in order to discover therapies that prevent or resolve illness relies on the bacterial capacity to adjust its metabolism and replication in response to various environmental cues as necessary. An extensive literature details the transcriptional alterations of host in response to in vitro environmental stressors, macrophage infection, and human illness. Various studies have recently revealed the finding of several microRNAs (miRNAs) that are believed to play an important role in the regulatory networks responsible for adaptability and virulence in Mycobacterium tuberculosis. We highlighted the growing data on the existence and quantity of several forms of miRNAs in the pathogenesis of M. tuberculosis, considered their possible relevance to disease etiology, and discussed how the miRNA-based signaling pathways regulate bacterial virulence factors.

Understanding microRNAs in the Context of Infection to Find New Treatments against Human Bacterial Pathogens

The development of RNA-based anti-infectives has gained interest with the successful application of mRNA-based vaccines. Small RNAs are molecules of RNA of <200 nucleotides in length that may control the expression of specific genes. Small RNAs include small interference RNAs (siRNAs), Piwi-interacting RNAs (piRNAs), or microRNAs (miRNAs). Notably, the role of miRNAs on the post-transcriptional regulation of gene expression has been studied in detail in the context of cancer and many other genetic diseases. However, it is also becoming apparent that some human miRNAs possess important antimicrobial roles by silencing host genes essential for the progress of bacterial or viral infections. Therefore, their potential use as novel antimicrobial therapies has gained interest during the last decade. The challenges of the transport and delivery of miRNAs to target cells are important, but recent research with exosomes is overcoming the limitations in RNA-cellular uptake, avoiding their degradation. Therefore, in this review, we have summarised the latest developments in the exosomal delivery of miRNA-based therapies, which may soon be another complementary treatment to pathogen-targeted antibiotics that could help solve the problem caused by multidrug-resistant bacteria.

Transient Focal Cerebral Ischemia Leads to miRNA Alterations in Different Brain Regions, Blood Serum, Liver, and Spleen

Ischemic stroke is characterized by an occlusion of a cerebral blood vessel resulting in neuronal cell death due to nutritional and oxygen deficiency. Additionally, post-ischemic cell death is augmented after reperfusion. These events are paralleled by dysregulated miRNA expression profiles in the peri-infarct area. Understanding the underlying molecular mechanism in the peri-infarct region is crucial for developing promising therapeutics. Utilizing a tMCAo (transient Middle Cerebral Artery occlusion) model in rats, we studied the expression levels of the miRNAs (miR) 223-3p, 155-5p, 3473, and 448-5p in the cortex, amygdala, thalamus, and hippocampus of both the ipsi- and contralateral hemispheres. Additionally, the levels in the blood serum, spleen, and liver and the expression of their target genes, namely, Nlrp3, Socs1, Socs3, and Vegfa, were assessed. We observed an increase in all miRNAs on the ipsilateral side of the cerebral cortex in a time-dependent manner and increased miRNAs levels (miR-223-3p, miR-3473, and miR-448-5p) in the contralateral hemisphere after 72 h. Besides the cerebral cortex, the amygdala presented increased expression levels, whereas the thalamus and hippocampus showed no alterations. Different levels of the investigated miRNAs were detected in blood serum, liver, and spleen. The gene targets were altered not only in the peri-infarct area of the cortex but selectively increased in the investigated non-affected brain regions along with the spleen and liver during the reperfusion time up to 72 h. Our results suggest a supra-regional influence of miRNAs following ischemic stroke, which should be studied to further identify whether miRNAs are transported or locally upregulated.

Probe into the Target and Mechanism of Jianpi Xiaoke Prescription for Treating Type 2 Diabetes Mellitus through miRNA Expression Profiling

Methods

Ten of the 31 SPF male Wistar rats were randomly taken as the control group; the remaining rats were fed a high-sugar and high-fat diet, combined with Streptozotocin (STZ, 35 mg/kg) that induced a type 2 diabetes model. The model rats were randomly divided into model groups (n = 11) and the JPXK group (n = 10). After 8 weeks of JPXK intervention, we detected the function of islet cells through HE staining and ELISA. High-pass sequencing technology was adopted to identify the differential expression of miRNA to explore the target of JPXK treatment, assess the relevant target genes, conduct functional analysis, and lastly verify the sequencing data by qRT-PCR.

Results

After treatment, FPG, FINS, and HOMA-IR levels of the treatment group improved significantly compared with those of the control group (P < 0.05). Among the miRNAs differentially expressed between the model group and the control group, there were 7 reversals after JPXK treatment, including miR-1-3p, miR-135a-5p, miR-181d-5p, miR-206-3p, miR-215, miR-3473, and miR-547-3p (log2FC ≥ 1 or ≤ -1, P < 0.05). Besides, the 1810 target genes associated with these 7 miRNAs were assessed by multiMiR. According to the results of the GO and KEGG analyses, they were associated with biological processes (e.g., glucose transport and fat cell formation), and it covered multiple signaling pathways, capable of regulating islet cell function (e.g., MAPK, PI3K-Akt, Ras, AMPK, and HIF-1 signaling pathways). The PCR verification results were consistent with the sequencing results.

Conclusion

This discovery interpreted the potential therapeutic targets and signaling pathways of JPXK prescription against T2DM based on miRNA expression profiling. In conclusion, our research provided novel research insights into traditional Chinese medicine (TCM) treatment of diabetes.

microRNA-382 suppresses the progression of pancreatic cancer through the PI3K/Akt signaling pathway by inhibition of Anxa3

Pancreatic cancer (PC) is a lethal cancer in the digestive system. microRNAs (miRNAs) have been demonstrated to participate in PC progression. In this context, we, thus, aimed to explore the mechanism of miR-382 in epithelial mesenchymal transition (EMT) and lymph node metastasis in PC in relation to Anxa3 and the PI3K/Akt signaling pathway. Gene expression data sets GSE16515, GSE71989, and GSE32676 were screened out, with the findings showing the significance of miR-382 and annexin A3 (Anxa3) in PC. A total of 115 PC patients were selected for determination of miR-382 and Anxa3 expression with lowly expressed miR-382 and highly expressed Anxa3 found via RT-quantitative PCR and Western blot analysis. Additionally, negative correlation was found between miR-382 and Anxa3 in PC. Dual-luciferase reporter gene assay and in situ hybridization results confirmed that miR-382 negatively regulated Anxa3. miR-382 targeted Anxa3 and suppressed PC progression by blocking the PI3K/Akt signaling pathway. After a series of gain- and loss-of function approaches, upregulation of miR-382 or silencing of Anxa3 inhibited the EMT and lymph node metastasis, as evidenced by increased level of E-cadherin and decreased level of N-cadherin, vimentin, vascular endothelial growth factor(VEGFR)-3, VEGF-C, and VEGF-D. Overexpression of miR-382 or downregulation of Anxa3 was shown to inhibit colony formation, migration, and invasion abilities of PC cells. Further, tumor xenograft in nude mice in vivo also confirmed the inhibitory role of miR-382 and silenced Anxa3 in lymph node metastasis in PC. Thus, this study provides promising therapeutic targets for PC treatment.NEW & NOTEWORTHY This study focused on the mechanism of miR-382 in epithelial mesenchymal transition and lymph node metastasis in PC in relation to Anxa3 and the PI3K/Akt signaling pathway. We found the inhibitory role of miR-382 in PC in vitro and in vivo.

A Flowable Placental Formulation Prevents Bleomycin-Induced Dermal Fibrosis in Aged Mice

Fibrosis, the thickening and scarring of injured connective tissue, leads to a loss of organ function. Multiple cell types, including T-cells, macrophages, fibrocytes, and fibroblasts/myofibroblasts contribute to scar formation via secretion of inflammatory factors. This event results in an increase in oxidative stress and deposition of excessive extracellular matrix (ECM), characteristic of fibrosis. Further, aging is known to predispose connective tissue to fibrosis due to reduced tissue regeneration. In this study, we investigated the anti-fibrotic activity of a flowable placental formulation (FPF) using a bleomycin-induced dermal fibrosis model in aged mice. FPF consisted of placental amnion/chorion- and umbilical tissue-derived ECM and cells. The mice were injected with either FPF or PBS, followed by multiple doses of bleomycin. Histological assessment of FPF-treated skin samples revealed reduced dermal fibrosis, inflammation, and TGF-β signaling compared to the control group. Quantitative RT-PCR and Next Generation Sequencing analysis of miRNAs further confirmed anti-fibrotic changes in the FPF-treated group at both the gene and transcriptional levels. The observed modulation in miRNAs was associated with inflammation, TGF-β signaling, fibroblast proliferation, epithelial-mesenchymal transition and ECM deposition. These results demonstrate the potential of FPF in preventing fibrosis and may be of therapeutic benefit for those at higher risk of fibrosis due to wounds, aging, exposure to radiation and genetic predisposition.

Over-expression of JAZF1 promotes cardiac microvascular endothelial cell proliferation and angiogenesis via activation of the Akt signaling pathway in rats with myocardial ischemia-reperfusion

Myocardial ischemia-reperfusion (I/R) injury is caused by endothelial dysfunction and enhanced oxidative stress. The overexpression of JAZF1, a zinc finger protein, has been reported to promote cell proliferation and suppress myogenic differentiation in type 2 diabetes. However, the involvement of JAZF1 in myocardial I/R injury remains to be unclear. The current study aims to investigate the role by which JAZF1 influences cardiac microvascular endothelial cells (CMECs) in a rat model of myocardial I/R injury. A total of 50 rats were established as a myocardial I/R model to isolate CMECs, with alterations in JAZF1 expression. After that, the gain- or loss-function of JAZF1 on the proliferation, apoptosis and tube formation ability of CMECs were evaluated by a series of in vitro experiments. Results indicated that JAZF1 was down-regulated in CMECs of rats with myocardial I/R injury. After treatment with JAZF1, the levels of VEGF, Bcl-2, PDGF and p-Akt/Akt were all increased; however, the expression of Bax, caspase-3, caspase-9, p-Bad/Bad, c-caspase-3/caspase-3, c-caspase-9/caspase-9, and p-FKHR/FKHR exhibited decreased levels; CMEC proliferation and angiogenesis were increased, while cell apoptosis was attenuated. CMECs transfected with JAZF1 shRNA exhibited the contrary tendencies. The key findings of this study suggest that the over-expression of JAZF1 alleviates myocardial I/R injury by enhancing proliferation and angiogenesis of CMECs and in turn inhibiting apoptosis of CMECs via the activation of the Akt signaling pathway.

Burkholderia thailandensis strain E555 is a surrogate for the investigation of Burkholderia pseudomallei replication and survival in macrophages

Background

Burkholderia pseudomallei is a human pathogen causing severe infections in tropical and subtropical regions and is classified as a bio-threat agent. B. thailandensis strain E264 has been proposed as less pathogenic surrogate for understanding the interactions of B. pseudomallei with host cells.

Results

We show that, unlike B. thailandensis strain E264, the pattern of growth of B. thailandensis strain E555 in macrophages is similar to that of B. pseudomallei. We have genome sequenced B. thailandensis strain E555 and using the annotated sequence identified genes and proteins up-regulated during infection. Changes in gene expression identified more of the known B. pseudomallei virulence factors than changes in protein levels and used together we identified 16% of the currently known B. pseudomallei virulence factors. These findings demonstrate the utility of B. thailandensis strain E555 to study virulence of B. pseudomallei.

Conclusions

A weakness of studies using B. thailandensis as a surrogate for B. pseudomallei is that the strains used replicate at a slower rate in infected cells. We show that the pattern of growth of B. thailandensis strain E555 in macrophages closely mirrors that of B. pseudomallei. Using this infection model we have shown that virulence factors of B. pseudomallei can be identified as genes or proteins whose expression is elevated on the infection of macrophages. This finding confirms the utility of B. thailandensis strain E555 as a surrogate for B. pseudomallei and this strain should be used for future studies on virulence mechanisms.

Electronic supplementary material

The online version of this article (10.1186/s12866-019-1469-8) contains supplementary material, which is available to authorized users.

The diagnostic value of circulating microRNAs in heart failure

Heart failure (HF) is a complex clinical syndrome, characterized by inadequate blood perfusion of tissues and organs caused by decreased heart ejection capacity resulting from structural or functional cardiac disorders. HF is the most severe heart condition and it severely compromises human health; thus, its early diagnosis and effective management are crucial. However, given the lack of satisfactory sensitivity and specificity of the currently available biomarkers, the majority of patients with HF are not diagnosed early and do not receive timely treatment. A number of studies have demonstrated that peripheral blood circulating nucleic acids [such as microRNAs (miRs), mRNA and DNA] are important for the diagnosis and monitoring of treatment response in HF. miRs have been attracting increasing attention as promising biomarkers, given their presence in body fluids and relative structural stability under diverse conditions of sampling. The aim of the present review was to analyze the associations between the mechanisms underlying the development of HF and the expression of miRs, and discuss the value of using circulating miRs as diagnostic biomarkers in HF management. In particular, miR-155, miR-22 and miR-133 appear to be promising for the diagnosis, prognosis and management of HF patients.

CP‑31398 attenuates endometrial cancer cell invasion, metastasis and resistance to apoptosis by downregulating MDM2 expression

Endometrial cancer (EC) is one of the most common malignancies of the female reproductive system, and metastasis is a major cause of mortality. In this study, we aimed to explore the role of CP-31398 in the migration, invasion and apoptosis of EC cells by its regulation of the expression of the murine double minute 2 (MDM2) gene. For this purpose, EC tissues and adjacent normal tissues were collected, and the positive expression rate of MDM2 in these tissues was assessed. Subsequently, the cellular 50% inhibitory concentration (IC50) of CP-31398 was measured. The EC RL95-2 and KLE cell lines had a higher MDM2 expression and were thus selected for use in subsequent experiments. The EC cells were then treated with CP-31398 (2 µg/ml), and were transfected with siRNA against MDM2 or an MDM2 overexpression plasmid in order to examine the effects of CP-31398 and MDM2 on EC cell activities. The expression of p53, p21, Bad, Bax, B-cell lymphoma-2 (Bcl-2), cytochrome c (Cyt-c), caspase-3, Cox-2, matrix metalloproteinase (MMP)-2 and MMP-9 was measured to further confirm the effects of CP-31398 on cell migration, invasion and apoptosis. Our results indicated that MDM2 was highly expressed in EC tissues. Notably, EC cell viability decreased with the increasing concentrations of CP-31398. The EC cells treated with CP-31398 or siRNA against MDM2 exhibited an increased apoptosis and a suppressed migration and invasion, corresponding to an increased expression of p53, p21, Bad, Bax, Cyt-c and caspase-3, as well as to a decreased expression of Bcl-2, Cox-2, MMP-2 and MMP-9. Moreover, treatment with CP-31398 and siRNA against MDM2 further enhanced these effects. Taken together, the findings of this study indicate that the CP-31398-mediated downregulation of MDM2 may suppress EC progression via its inhibitory role in EC cell migration, invasion and resistance to apoptosis. Therefore, treatment with CP-31398 may prove to be possible therapeutic strategy for EC.

Regulation of TLR signaling pathways by microRNAs: implications in inflammatory diseases

The control of the immune response during the development of some diseases is crucial for the maintenance or restoration of homeostasis. Several mechanisms can initiate inflammation, one of which is the activation of toll-like receptors (TLRs), necessary to initiate the immune response to eliminate an infection. However, inappropriate activation can compromise immunological homeostasis, leading to pathologies such as autoimmune diseases, chronic inflammation, and even cancer. Regulatory mechanisms that intervene in the initiation or modulation of inflammation include microRNAs (miRNAs), which have emerged as key post-transcriptional regulators of proteins involved in distinct cellular processes, such as regulation of the immune response. The focus of this review is on the diverse roles of miRNAs in the regulation of TLR-signaling pathways by targeting multiple molecules, including TLRs, the signaling proteins and cytokines induced by TLRs. It will also address the relationships of these molecules with some diseases that involve inflammation such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), cancer, as well as bacterial or viral infections.

Evaluation of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for identifying Burkholderia pseudomallei and Burkholderia thailandensis isolates

Since Burkholderia thailandensis is included in the reference spectra of the VITEK MS libraries rather than Burkholderia pseudomallei, B. pseudomallei cannot be correctly identified in the current version of VITEK MS. This study was undertaken to evaluate the utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with the VITEK MS plus system in the detection of B. pseudomallei and B. thailandensis isolates. For each species, we increased the reference spectra, and then, a SuperSpectrum was created based on the selection of 39 specific masses. In a second step, we validated the SuperSpectra with 106 isolates identified by 16S rRNA gene sequencing. The results showed that there was 100% agreement between the validation strains analyzed by MALDI-TOF MS and those evaluated using 16S rRNA gene sequencing analysis methods. Therefore, MALDI-TOF MS is a promising, rapid, and economical method to monitor the outbreaks and spread of B. pseudomallei and B. thailandensis isolates.

miR-17-92 functions as an oncogene and modulates NF-κB signaling by targeting TRAF3 in MGC-803 human gastric cancer cells

The miR-17-92 cluster plays either an oncogenic or anti-oncogenic role in cancer progression in diverse human cancers. However, the underlying mechanisms of the miR-17-92 cluster in gastric cancer have not yet been fully elucidated. In this study, the function of the miR-17-92 cluster in diverse aspects of MGC-803 gastric cancer cells was systematically elucidated. The enforced introduction of the miR-17-92 cluster into the MGC-803 cells significantly promoted cell growth due to the increased cellular proliferation and decreased cellular apoptosis, which were detected by CCK-8, cell viability and TUNEL assays. Moreover, the results of western blot analyses revealed that the activated protein kinase B (AKT), extracellular-signal-regulated kinase (ERK) and nuclear factor (NF-κB) signaling pathways were activated in these processes. Moreover, the overexpression of the miR-17-92 cluster markedly enhanced the migratory and invasive abilities of the MGC-803 cells, which was associated with the occurrence of epithelial-mesenchymal transition (EMT). Tumor necrosis factor receptor associated factor 3 (TRAF3), which negatively regulates the NF-κB signaling pathway, was identified as a direct target of miR-17-92. Furthermore, TRAF3 silencing enhanced the oncogenic functions of the miR-17-92 cluster in the MGC-803 cells, including the increased cellular proliferation, migration and invasion. Moreover, immunohistochemical staining and survival analyses of a gastric cancer tissue microarray revealed that TRAF3 functioned as a tumor suppressor in gastric cancer. Taken together, the findings of this study provide new insight into the specific biological functions of the miR-17-92 cluster in gastric cancer progression by directly targeting TRAF3.

Inhibitory effect of microRNA-154 targeting WHSC1 on cell proliferation of human skin squamous cell carcinoma through mediating the P53 signaling pathway

OBJECTIVE

Skin squamous cell carcinoma (SCC) is a common, morbid, and frequently lethal malignancy and ranks as the sixth most deadly cancer worldwide. Hence, this study aims to explore the effect of microRNA-154 (miR-154) targeting WHSC1 on proliferation and apoptosis of SCC cells via the P53 signaling pathway.

METHODS

The targeting relationship between WHSC1 and miR-154 was validated using dual-luciferase reporter assay. Normal human epidermal keratinocytes (NHEK) were included, and SCC A431 and SCC-15 cell lines were cultured and transfected with miR-154 mimic, miR-154 inhibitor or siRNA-WHSC1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were used for the miR-154 expression and levels of WHSC1, P53 signaling pathway- and apoptosis-related genes. MTT assay and flow cytometry were applied to determine the cell viability and apoptosis.

RESULTS

WHSC1 is a target gene of miR-154. MiR-154 negatively regulated WHSC1 expression and inhibited the activation of P53 signaling pathway. In response to miR-154 mimic or siRNA-WHSC1, SCC A431 and SCC-15 cell lines exhibited increased expression of P73, P16 and Bax, decreased expression of WHSC1, P53, c-myc and Bcl-2, as well as attenuated cell viability and enhanced cell apoptosis. The treatment of miR-154 inhibitor reversed the tendency.

CONCLUSION

These results demonstrate that up-regulation of miR-154 inhibits proliferation and induces apoptosis of human skin SCC cells by down-regulating WHSC1 and blocking the P53 signaling pathway.

Effects of microRNA-129 and its target gene c-Fos on proliferation and apoptosis of hippocampal neurons in rats with epilepsy via the MAPK signaling pathway

This study aims to investigate the effect of microRNA-129 (miR-129) on proliferation and apoptosis of hippocampal neurons in epilepsy rats by targeting c-Fos via the MAPK signaling pathway. Thirty rats were equally classified into a model group (successfully established as chronic epilepsy models) and a normal group. Expression of miR-129, c-Fos, bax, and MAPK was detected by RT-qPCR and Western blotting. Hippocampal neurons were assigned into normal, blank, negative control (NC), miR-129 mimic, miR-129 inhibitor, siRNA-c-Fos, miR-129 inhibitor+siRNA-c-Fos groups. The targeting relationship between miR-129 and c-Fos was predicted and verified by bioinformatics websites and dual-luciferase reporter gene assay. Cell proliferation after transfection was measured by MTT assay, and cell cycle and apoptosis by flow cytometry. c-Fos is a potential target gene of miR-129. Compared with the normal group, the other six groups showed a decreased miR-129 expression; increased expression of expression of c-Fos, Bax, and MAPK; decreased proliferation; accelerated apoptosis; more cells arrested in the G1 phase; and fewer cells arrested in the S phase. Compared with the blank and NC groups, the miR-129 mimic group and the siRNA-c-Fos group showed decreased expression of c-Fos, Bax, and MAPK, increased cells proliferation, and decreased cell apoptosis, fewer cells arrested in the G1 phase and more cells arrested in the S phase. However, the miR-129 inhibitor groups showed reverse consequences. This study suggests that miR-129 could inhibit the occurrence and development of epilepsy by repressing c-Fos expression through inhibiting the MAPK signaling pathway.

Circulating miR-19b and miR-181b are potential biomarkers for diabetic cardiomyopathy

Diabetic cardiomyopathy is characterized by metabolic changes in the myocardium that promote a slow and silent dysfunction of muscle fibers, leading to myocardium remodelling and heart failure, independently of the presence of coronary artery diseases or hypertension. At present, no imaging methods allow an early diagnosis of this disease. Circulating miRNAs in plasma have been proposed as biomarkers in the prognosis of several cardiac diseases. This study aimed to determine whether circulating miRNAs could be potential biomarkers of diabetic cardiomyopathy. Mice that were fed with a high fat diet for 16 months, showed metabolic syndrome manifestations, cardiac hypertrophy (without hypertension) and a progressive cardiac function decline. At 16 months, when maximal degree of cardiac dysfunction was observed, 15 miRNAs from a miRNA microarray screening in myocardium were selected. Then, selected miRNAs expression in myocardium (at 4 and 16 months) and plasma (at 4, 12 and 16 months) were measured by RT-qPCR. Circulating miR-19b-3p and miR-181b-5p levels were associated with myocardium levels during the development of diabetic cardiomyopathy (in terms of cardiac dysfunction), suggesting that these miRNAs could be suitable biomarkers of this disease in asymptomatic diabetic patients.

The Clinical Application of MicroRNAs in Infectious Disease

MicroRNAs (miRNAs) are short single-stranded non-coding RNA sequences that posttranscriptionally regulate up to 60% of protein encoding genes. Evidence is emerging that miRNAs are key mediators of the host response to infection, predominantly by regulating proteins involved in innate and adaptive immune pathways. miRNAs can govern the cellular tropism of some viruses, are implicated in the resistance of some individuals to infections like HIV, and are associated with impaired vaccine response in older people. Not surprisingly, pathogens have evolved ways to undermine the effects of miRNAs on immunity. Recognition of this has led to new experimental treatments, RG-101 and Miravirsen—hepatitis C treatments which target host miRNA. miRNAs are being investigated as novel infection biomarkers, and they are being used to design attenuated vaccines, e.g., against Dengue virus. This comprehensive review synthesizes current knowledge of miRNA in host response to infection with emphasis on potential clinical applications, along with an evaluation of the challenges still to be overcome.