TGF-β-associated miR-27a inhibits dendritic cell-mediated differentiation of Th1 and Th17 cells by TAB3, p38 MAPK, MAP2K4 and MAP2K7

MicroRNAs are dysregulated in peripheral blood mononuclear cells in multiple sclerosis and correlate with T cell mediators

T cell mediators and microRNAs are involved in the pathogenesis of multiple sclerosis (MS), but their interaction largely remains undetermined. We investigated by RT-qPCR the dysregulation of microRNAs in peripheral blood mononuclear cells of MS patients versus healthy controls, according to radiological disease activity or treatment. Several microRNAs correlated positively/negatively with IL21/FOXP3 mRNA expression, but not with serum neurofilament light chain levels. Cytokine expression is conceivably balanced by several regulators, whereas microRNAs possibly target upstream transcription factors rather than directly cytokine mRNAs. Functional studies are needed to investigate their interaction, notably for the predicted targeting of FOXP3 by miR-34c-5p.

Non-coding RNA in tumor-infiltrating regulatory T cells formation and associated immunotherapy

Cancer immunotherapy has exhibited promising antitumor effects in various tumors. Infiltrated regulatory T cells (Tregs) in the tumor microenvironment (TME) restrict protective immune surveillance, impede effective antitumor immune responses, and contribute to the formation of an immunosuppressive microenvironment. Selective depletion or functional attenuation of tumor-infiltrating Tregs, while eliciting effective T-cell responses, represents a potential approach for anti-tumor immunity. Furthermore, it does not disrupt the Treg-dependent immune homeostasis in healthy organs and does not induce autoimmunity. Yet, the shared cell surface molecules and signaling pathways between Tregs and multiple immune cell types pose challenges in this process. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), regulate both cancer and immune cells and thus can potentially improve antitumor responses. Here, we review recent advances in research of tumor-infiltrating Tregs, with a focus on the functional roles of immune checkpoint and inhibitory Tregs receptors and the regulatory mechanisms of ncRNAs in Treg plasticity and functionality.

miR-27a-3p alleviates lung transplantation-induced bronchiolitis obliterans syndrome (BOS) via suppressing Smad-mediated myofibroblast differentiation and TLR4-induced dendritic cells maturation

BACKGROUND

Bronchiolitis obliterans syndrome (BOS), induced by a chronic rejection, remains a significant obstacle for end-stage lung diseases after lung transplantation. We have previously determined that the small non-coding mRNA (miRNA) miR-27a-3p maintained the immature state of dendritic cells (DCs) via the interleukin 10 (IL-10)-dependent regulatory pathway. Such status helped in preventing rejection and alleviating BOS. The present study explored mechanisms how miR-27a-3p may suppress the fibrosis as well as the maturation of DCs, ultimately attenuating BOS in vitro and in vivo.

METHODS/RESULTS

In our tracheal transplantation mouse model, the expression of Smad2, Smad4, and αSMA were significantly decreased in the miR-27a-3p-transfected DCs (p < 0.0001, p = 0.0006, and p = 0.0002 respectively). Moreover, the expression of fibrosis markers (α-SMA, collagen I, and Fn) were potently inhibited in the miR-27a-3p-transfected NIH-3 T3 cells (p < 0.0001, p = 0.00148, and p < 0.0001 respectively). At the same time, reversed results were observed in the inhibitor group (p = 0.0002, p < 0.0001, and p < 0.0001 respectively), indicating that miR-27a-3p could directly inhibit myofibroblast differentiation. Furthermore, in the tracheal transplanted mice, the population of Treg cells was significantly decreased (p < 0.0001). In contrast, Th17 cells were down-regulated in the miR-27a-3p-transfected DCs group (p < 0.0001), accompanied by the decreased IL-17 levels (p = 0.0007) and the induction of TGF-β1 and IL-10 (p < 0.0001 and p = 0.0016 respectively). Further mechanistic studies indicated that miR-27a-3p altered the maturation of DCs by targeting TLR4 and IRAK (p < 0.0001 and p = 0.0002 respectively).

CONCLUSIONS

Our study suggests that miR-27a-3p selectively blocked the TGF-β1/Smad pathways to suppress the myofibroblast differentiation and targeted the TRL4/IRAK4 pathway to restrain DCs maturation, thus attenuating BOS. Our findings suggest that miR-27a-3p is a potential active molecule on BOS management after lung transplantation.

Recent Progress in the Identification of Early Transition Biomarkers from Relapsing-Remitting to Progressive Multiple Sclerosis

Despite extensive research into the pathophysiology of multiple sclerosis (MS) and recent developments in potent disease-modifying therapies (DMTs), two-thirds of relapsing-remitting MS patients transition to progressive MS (PMS). The main pathogenic mechanism in PMS is represented not by inflammation but by neurodegeneration, which leads to irreversible neurological disability. For this reason, this transition represents a critical factor for the long-term prognosis. Currently, the diagnosis of PMS can only be established retrospectively based on the progressive worsening of the disability over a period of at least 6 months. In some cases, the diagnosis of PMS is delayed for up to 3 years. With the approval of highly effective DMTs, some with proven effects on neurodegeneration, there is an urgent need for reliable biomarkers to identify this transition phase early and to select patients at a high risk of conversion to PMS. The purpose of this review is to discuss the progress made in the last decade in an attempt to find such a biomarker in the molecular field (serum and cerebrospinal fluid) between the magnetic resonance imaging parameters and optical coherence tomography measures.

Role of miRNA in Melanoma Development and Progression

Melanoma is one of the most aggressive and progressive skin cancers. It develops from normal pigment-producing cells known as melanocytes, so it is important to know the mechanism behind such transformations. The study of metastasis mechanisms is crucial for a better understanding the biology of neoplastic cells. Metastasis of melanoma, or any type of cancer, is a multi-stage process in which the neoplastic cells leave the primary tumour, travel through the blood and/or lymphatic vessels, settle in distant organs and create secondary tumours. MicroRNA (miRNA) can participate in several steps of the metastatic process. This review presents the role of miRNA molecules in the development and progression as well as the immune response to melanoma.

The Roles of MiRNAs (MicroRNAs) in Melanoma Immunotherapy

Melanoma is the most aggressive form of skin cancer, characterized by life-threatening and rapidly spreading progression. Traditional targeted therapy can alleviate tumors by inactivating hyperactive kinases such as BRAF or MEK but inevitably encounters drug resistance. The advent of immunotherapy has revolutionized melanoma treatment and significantly improved the prognosis of melanoma patients. MicroRNAs (miRNAs) are intricately involved in innate and adaptive immunity and are implicated in melanoma immunotherapy. This systematic review describes the roles of miRNAs in regulating the functions of immune cells in skin and melanoma, as well as the involvement of miRNAs in pharmacology including the effect, resistance and immune-related adverse events of checkpoint inhibitors such as PD-1 and CTLA-4 inhibitors, which are used for treating cutaneous, uveal and mucosal melanoma. The expressions and functions of miRNAs in immunotherapy employing tumor-infiltrating lymphocytes and Toll-like receptor 9 agonists are also discussed. The prospect of innovative therapeutic strategies such as the combined administration of miRNAs and immune checkpoint inhibitors and the nanotechnology-based delivery of miRNAs are also provided. A comprehensive understanding of the interplay between miRNAs and immunotherapy is crucial for the discovery of reliable biomarkers and for the development of novel miRNA-based therapeutics against melanoma.

MiR-27a as a diagnostic biomarker and potential therapeutic target in systemic sclerosis

Systemic sclerosis (SSc) or scleroderma is a multiorgan rheumatoid disease characterized by skin tightening or organ dysfunction due to fibrosis, vascular damage, and autoimmunity. No specific cause has been discovered for this illness, and hence no effective treatment exists for it. On the other hand, due to the lack of diagnostic biomarkers capable of effectively and specifically differentiating the patients, early diagnosis has not been possible. Due to their potent regulatory roles in molecular pathways, microRNAs are among the novel candidates for the diagnosis and treatment of diseases like SSc. MiR-27a is a microRNA known for its role in the pathogenesis of fibrosis and cancer, both of which employ similar signaling pathways; hence we hypothesized that Mir-27a could be dysregulated in the blood of individuals affected by SSc and it might be useful in the diagnosis or treatment of this disease. Blood was collected from 60 SSc patients (30 limited and 30 diffuse) diagnosed by a rheumatologist according to ACR/AULAR criteria; following RNA isolation and cDNA synthesis; real-time qPCR was performed on the samples using Taq-Man probes and data were analyzed by the ΔΔCT method. Also, potential targets of miR-27a were evaluated using bioinformatics. It was revealed that miR-27a was significantly down-regulated in SSc patients in comparison to healthy individuals, but there was no difference in miR-27 expression between limited and diffused SSc patients. Besides, miR-27a was found to target several contributing factors to SSc. It seems that miR-27a has a protective role in SSc, and its downregulation could result in the disease's onset. Based on bioinformatics analyses, it is speculated that miR-27a likely targets factors contributing to the pathogenesis of SSc, which are elevated upon the downregulation of miR-27a; hence, miR-27a mimics could be considered as potential therapeutic agents for the treatment of SSc in future studies. Since no difference was observed between limited and diffuse patient groups, it is unlikely that this microRNA has a role in disease progression. According to ROC analysis of qPCR data, miR-27a could be employed as a valuable diagnostic biomarker for SSc.

The association of plasma levels of miR-146a, miR-27a, miR-34a, and miR-149 with coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is considered to be one of the most pivotal causes of death in the world. Over the past two decades, significant changes occurred in the diagnosis, prognosis, and treatment of CAD, which has helped reduce mortality rates. microRNAs (miRs) are a class of more than 5000 non-encoding RNA molecules (21-25 nucleotides across the length) that regulate complex biological processes. Today, miRNAs are used to study cardiovascular diseases. In the present study, the expression of miR-146a،miR-27, miR-149, and miR-34a in plasma suffering from CAD and the control group were investigated.

METHODS AND RESULTS

The present research was performed on 30 men with CAD and 30 healthy men as controls. The expression levels of miR-146a, miR-27a, miR-149, and miR-34a in the plasma of patients with CAD and the control group were measured using real-time PCR. Also, the correlation between the expression of circulating miRs levels and biochemical LDL-C, HDL-C, BMI, and total cholesterol was evaluated. The expression of miR-27a in the plasma of the CAD group was higher than in the control group (p = 0.020). The expression of miR-146a was downregulated in CAD patients compared to normal subjects (p = 0. 026). However, the expression of miR-34a, miR-149 in the plasma of CAD patients was not significantly different with the control group. In addition to, a direct correlation was found between the expression of miR-146a and HDL-c, the expression of miR-27a and LDL-C and the expression of miR-34a and total cholesterol. Also, the negative correlation between expressions of miR-149 with BMI was reported.

CONCLUSION

The obtained results demonstrated that miRs were closely related to biochemical factors and it points out the fact that miRNAs can be applied as a potential strategy for diagnosis and treatment of CAD.

Maternal genetic effect on apoptosis of ovarian granulosa cells induced by cadmium

To investigate the maternal genetic effects of cadmium (Cd) -induced apoptotic in ovarian granulosa cells (OGCs). Herein, pregnant Sprague-Dawley (SD) rats were treated with CdCl₂ from day 1 to day 20, F1 and F2 female rats were mated with untreated males to produce F2 and F3 generations. Under this model, significant apoptotic changes were observed in F1 OGCs induced by Cd (Liu et al., 2021). In this study, no apoptotic bodies were found in F2 while the mitochondrial membrane potential level decreased significantly but not in F3. Moreover, significant changes in bcl-xl and Cle-CASPASE-9/Pro-CASPASE-9 ratio were observed in F2 which disappears in F3. The DNA methylation sequencing and microRNAs (miRNAs) microarray reveals different gene methylation and miRNAs changes in F2 and F3. Notably, miR-132-3p, miR-199a-5p, and miR-1949 were upregulated in F1 while downregulated in F2 and F3 in which apoptosis gradually disappeared. Further, miRNA maturation-related genes and transcription factors have different expression patterns in F1-F3. These results indicate that maternal genetic intergenerational/transgenerational effect of Cd-induced OGCs apoptotic was significantly attenuated and disappeared, which was related to self-repair regulation of apoptosis-related genes. The changes in apoptosis-related miRNAs and DNA methylation may be important, and the role of transcription factors deserve attention.

TNF-α induces up-regulation of MicroRNA-27a via the P38 signalling pathway, which inhibits intervertebral disc degeneration by targeting FSTL1

The mechanism of intervertebral disc degeneration is still unclear, and there are no effective therapeutic strategies for treating this condition. miRNAs are naturally occurring macromolecules in the human body and have many biological functions. Therefore, we hope to elucidate whether miRNAs are associated with intervertebral disc degeneration and the underlying mechanisms involved. In our study, differentially expressed miRNAs were predicted by the GEO database and then confirmed by qPCR and in situ hybridization. Apoptosis of nucleus pulposus cells was detected by flow cytometry and Bcl2, Bax and caspase 3. Deposition of extracellular matrix was assessed by Alcian blue staining, and the expression of COX2 and MMP13 was detected by immunofluorescence, Western blot and qPCR. Moreover, qPCR was used to detect the expression of miR27a and its precursors. The results showed that miR27a was rarely expressed in healthy intervertebral discs but showed increased expression in degenerated intervertebral discs. Ectopic miR27a expression inhibited apoptosis, suppressed the inflammatory response and attenuated the catabolism of the extracellular matrix by targeting FSTL1. Furthermore, it seems that the expression of miR27a was up-regulated by TNF-α via the P38 signalling pathway. So we conclude that TNF-α and FSTL1 engage in a positive feedback loop to promote intervertebral disc degeneration. At the same time, miR27a is up-regulated by TNF-α via the P38 signalling pathway, which ameliorates inflammation, apoptosis and matrix degradation by targeting FSTL1. Thus, this negative feedback mechanism might contribute to the maintenance of a low degeneration load and would be beneficial to maintain a persistent chronic disc degeneration.

Circulating miRNAs as Promising Biomarkers to Evaluate ECMO Treatment Responses in ARDS Patients

The use of extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) has increased in the last decade. However, mortality remains high, and the complexity of ECMO requires individualized treatment. There are some biomarkers to monitor progression and predict clinical outcomes of ARDS. This project aims to advance the management of ARDS patients treated with ECMO by exploring miRNA expression in whole blood. The analysis was conducted on two groups with different length of ECMO: Group A (longer runs) and group B (shorter runs). We analyzed miRNAs before ECMO cannulation, and at 7 and 14 days of ECMO support. Our results showed that in the group B patients, 11 deregulated miRNAs were identified, and showed an opposite trend of expression compared to the group A patients. In silico analysis revealed that these 11 miRNAs were related to processes involved in the pathogenesis and evolution of ARDS. This scenario could represent homeostatic mechanisms by which, in ECMO responsive patients, pathways activated during ARDS progression are switched-off. Circulating miRNAs could represent promising biomarkers to monitor the evolution of ARDS under ECMO support. Further studies may shed light on this topic to improve a personalized approach in such a complex setting of patients.

Resveratrol for targeting the tumor microenvironment and its interactions with cancer cells

Tumor resistance to therapy modalities is one of the major challenges to the eradication of cancer cells and complete treatment. Tumor includes a wide range of cancer and non-cancer cells that play key roles in the proliferation of cancer cells and suppression of anti-tumor immunity. For overcoming tumor resistance to therapy, it is important to have in-depth knowledge relating to intercellular communications within the tumor microenvironment (TME). TME includes various types of immune cells such as CD4 + T lymphocytes, cytotoxic T lymphocytes (CTLs), natural killer (NK) cells, macrophages, and T regulatory cells (Tregs). Furthermore, some non-immune cells like cancer stem cells (CSCs), mesenchymal stem cells (MSCs), and cancer-associated fibroblasts (CAFs) are involved in the promotion of tumor growth. The interactions between these cells with cancer cells play a key role in tumor growth or inhibition. Resveratrol as a natural agent has shown the ability to modulate the immune system to potentiate anti-tumor immunity and also help to attenuate cancer cells and CSCs resistance. Thus, this review explains how resveratrol can modulate interactions within TME.

The emerging role of miRNA in the perturbation of tumor immune microenvironment in chemoresistance: Therapeutic implications

Chemoresistance is a major hindrance in cancer chemotherapies, a leading cause of tumor recurrence and cancer-related deaths. Cancer cells develop numerous strategies to elude immune attacks and are regulated by immunological factors. Cancer cells can alter the expression of several immune modulators to upregulate the activities of immune checkpoint pathways. Targeting the immune checkpoint inhibitors is a part of the cancer immunotherapy altered during carcinogenesis. These immune modulators have the capability to reprogram the tumor microenvironment, thereby change the efficacy of chemotherapeutics. In general, the sensitivity of drugs is reduced in the immunosuppressive tumor microenvironment, resulting in chemoresistance and tumor relapse. The regulation of microRNAs (miRNAs) is well established in cancer initiation, progression, and therapy. Intriguingly, miRNA affects cancer immune surveillance and immune response by targeting immune checkpoint inhibitors in the tumor microenvironment. miRNAs alter the gene expression at the post-transcriptional level, which modulates both innate and adaptive immune systems. Alteration of tumor immune microenvironment influences drug sensitivity towards cancer cells. Besides, the expression profile of immune-modulatory miRNAs can be used as a potential biomarker to predict the response and clinical outcomes in cancer immunotherapy and chemotherapy. Recent evidences have revealed that cancer-derived immune-modulatory miRNAs might be promising targets to counteract cancer immune escape, thereby increasing drug efficacy. In this review, we have compiled the role of miRNAs in overcoming the chemoresistance by modulating tumor microenvironment and discussed their preclinical and clinical implications.

Remodeling of Stromal Cells and Immune Landscape in Microenvironment During Tumor Progression

The molecular understanding of carcinogenesis and tumor progression rests in intra and inter-tumoral heterogeneity. Solid tumors confined with vast diversity of genetic abnormalities, epigenetic modifications, and environmental cues that differ at each stage from tumor initiation, progression, and metastasis. Complexity within tumors studied by conventional molecular techniques fails to identify different subclasses in stromal and immune cells in individuals and that affects immunotherapies. Here we focus on diversity of stromal cell population and immune inhabitants, whose subtypes create the complexity of tumor microenvironment (TME), leading primary tumors towards advanced-stage cancers. Recent advances in single-cell sequencing (epitope profiling) approach circumscribes phenotypic markers, molecular pathways, and evolutionary trajectories of an individual cell. We discussed the current knowledge of stromal and immune cell subclasses at different stages of cancer development with the regulatory role of non-coding RNAs. Finally, we reported the current therapeutic options in immunotherapies, advances in therapies targeting heterogeneity, and possible outcomes.

Expression correlation attenuates within and between key signaling pathways in chronic kidney disease

Background

Compared to the conventional differential expression approach, differential coexpression analysis represents a different yet complementary perspective into diseased transcriptomes. In particular, global loss of transcriptome correlation was previously observed in aging mice, and a most recent study found genetic and environmental perturbations on human subjects tended to cause universal attenuation of transcriptome coherence. While methodological progresses surrounding differential coexpression have helped with research on several human diseases, there has not been an investigation of coexpression disruptions in chronic kidney disease (CKD) yet.

Methods

RNA-seq was performed on total RNAs of kidney tissue samples from 140 CKD patients. A combination of differential coexpression methods were employed to analyze the transcriptome transition in CKD from the early, mild phase to the late, severe kidney damage phase.

Results

We discovered a global expression correlation attenuation in CKD progression, with pathway Regulation of nuclear SMAD2/3 signaling demonstrating the most remarkable intra-pathway correlation rewiring. Moreover, the pathway Signaling events mediated by focal adhesion kinase displayed significantly weakened crosstalk with seven pathways, including Regulation of nuclear SMAD2/3 signaling. Well-known relevant genes, such as ACTN4, were characterized with widespread correlation disassociation with partners from a wide array of signaling pathways.

Conclusions

Altogether, our analysis reported a global expression correlation attenuation within and between key signaling pathways in chronic kidney disease, and presented a list of vanishing hub genes and disrupted correlations within and between key signaling pathways, illuminating on the pathophysiological mechanisms of CKD progression.

Mir-27a-3p attenuates bronchiolitis obliterans in vivo via the regulation of dendritic cells' maturation and the suppression of myofibroblasts' differentiation

Bronchiolitis obliterans (BO), is a chronic rejection phenotype characterized by chronic small airway fibrous obliteration, hinders the patients who suffer from lung transplanting for surviving longer. Cell-based therapies using dendritic cells (DCs) and T regulatory cells (Tregs) have been developed to regulate allograft rejection, and to induce and maintain immune tolerance. In the present study, the effects of mir-27a-3p on regulating DCs as well as resulting effects on BO attenuation have been investigated. According to our reporter assays, the potential targets of mir-27a-3p were Smad2, sprouty2, and Smad4, respectively. Furthermore, sprouty2 inhibition by mir-27-3p indirectly activated extracellular regulated protein kinases (ERK) and increased IL-10 production in DCs. This led to a positive feedback loop that maintained the immature state of DCs via IL-10/JAK/STAT3 pathway, and caused an increase in Foxp3⁺ CD4⁺ T cells amount as well as TGF-β level. Furthermore, mir-27a-3p regulated TGF-β function, inhibited TGF-β/Smad pathway, and suppressed myofibroblast differentiation through influencing the function of Smad2 and Smad4. In short, the study indicated the effect of mir-27a-3p on suppressing DC maturation, which implicated the potential clinical application in treating postlung transplant BO.

An autophagy-related model of 4 key genes for predicting prognosis of patients with laryngeal cancer

Autophagy, a major cause of cancer-related death, is correlated with the pathogenesis of various diseases including cancers. Our study aimed to develop an autophagy-related model for predicting prognosis of patients with laryngeal cancer.We analyzed the correlation between expression profiles of autophagy-related genes (ARGs) and clinical outcomes in 111 laryngeal cancer patients from The Cancer Genome Atlas (TCGA). Afterward, gene functional enrichment analyses of gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed to find the major biological attributes. Univariate Cox regression analyses and multivariate Cox regression analyses were performed to screen ARGs whose expression profiles were significantly associated with laryngeal cancer patients overall survival (OS). Furthermore, to provide the doctors and patients with a quantitative method to perform an individualized survival prediction, we constructed a prognostic nomogram.Thirty eight differentially expressed ARGs were screened out in laryngeal cancer patients through the TCGA database. Related functional enrichments may act as tumor-suppressive roles in the tumorigenesis of laryngeal cancer. Subsequently, 4 key prognostic ARGs (IKBKB, ST13, TSC2, and MAP2K7) were identified from all ARGs by the Cox regression model, which significantly correlated with OS in laryngeal cancer. Furthermore, the risk score was constructed, which significantly divided laryngeal cancer patients into high- and low-risk groups. Integrated with clinical characteristics, gender, N and the risk score are very likely associated with patients OS. A prognostic nomogram of ARGs was constructed using the Cox regression model.Our study could provide a valuable prognostic model for predicting the prognosis of laryngeal cancer patients and a new understanding of autophagy in laryngeal cancer.

LncRNA NEAT1 regulated inflammation and apoptosis in a rat model of sepsis-induced acute kidney injury via MiR-27a-3p/TAB3 axis

This study explored the mechanism of NEAT1 in sepsis-induced AKI rats. Cecal ligation punctures (CLP)-induced AKI rats were injected with siRNA-NEAT1 lentivirus. Kidney histopathology and apoptosis were evaluated via hematoxylin-eosin and TUNEL staining, respectively. ELISA determined the levels of Blood urea nitrogen (BUN), serum creatinine (SCr), neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), TNF-α, Interleukin (IL)-1β, and IL-6. Colorimetry measured malondialdehyde (MDA), superoxide dismutase (SOD) activities. qPCR analyzed NEAT1, miR-27a-3p, TAB3, Bcl-2, and Bax expressions. siNEAT1 reversed the promotive effect of CLP on kidney histopathological injury, and BUN, SCr, NGAL, KIM-1, TNF-α, IL-1β, IL-6, MDA, and Bax levels and apoptosis, but raised CLP-downregulated SOD and Bcl-2 levels. NEAT1 sponged miR-27a-3p which targeted TAB3. siNEAT1 upregulated miR-27a-3p and downregulated TAB3 expression. TAB3 overexpression reversed the inhibitory effect of siNEAT1 on the LPS-induced apoptosis of HK-2 cells. siNEAT1 alleviated sepsis-induced AKI in rats and LPS-induced sepsis of cells via miR-27a-3p/TAB3 axis.

microRNA-124-3p inhibits tumourigenesis by targeting mitogen-activated protein kinase 4 in papillary thyroid carcinoma

The study aimed to investigate the role of miR-124-3p and its potential molecular mechanism in papillary thyroid cancer (PTC). The expression of miR-124-3p and mitogen-activated protein kinase 4 (MAP2K4) in human thyroid follicular epithelial cell line (NTHY-ORI3-1) and human papillary thyroid carcinoma cell lines (SW1736, BCPAP, TPC-1 and K1) was measured by RT-qPCR. Cell proliferation was measured by CCK-8, while cell cycle and apoptosis rate were measured by flow cytometry. Invasive ability and migrative ability were measured by transwell assay and wound healing assay, respectively. Western blot was used to detect the levels of relative proteins. In vivo, TPC-1 cells transfected with miR-124-3p mimic were subcutaneously injected into the flank of the mice to form tumour. After successful modelling, mice were divided into two groups (n = 10): Control group and miR-124-3p mimic group. The present study showed that miR-124-3p was lowly expressed, while MAP2K4 was highly expressed in PTC cell lines. Besides, miR-124-3p targeted MAP2K4 and negatively regulated MAP2K4 in TPC-1 cells. In addition, miR-124-3p inhibited the proliferation and motility, and induced apoptosis and cell cycle arrest of TPC-1 cells by inactivating MAP2K4/JNK/JunD pathway. Furthermore, miR-124-3p inhibited tumour formation by downregulating MAP2K4 level in vivo. In conclusion, the study provided a novel molecular mechanism of miR-124-3p in the progress of PTC. SIGNIFICANCE OF THE STUDY: Papillary thyroid cancer (PTC) is the most important pathological type of thyroid cancer, accounting for 80% of thyroid cancer. miR-124-3p exhibited significant inhibitory role in the transformation and development of malignant tumours. However, in PTC, the roles and its potential molecular mechanism are unclear. Here, the study investigated the roles of miR-124-3p in the progress of PTC and its potential molecular mechanism. We found that miR-124-3p inhibited the proliferation and motility, and induced apoptosis and cell cycle arrest in PTC cells. This study provided a novel molecular mechanism of miR-124-3p in the progress of PTC.

Butyrate-producing bacteria and the gut-heart axis in atherosclerosis

The gut microbiota plays an important role in controlling atherosclerosis progression to support the link between the gut and coronary heart disease. Recent studies have shown that an imbalance in the gut-heart axis due to the gut microbiota plays an important role in atherosclerosis progression. The gut microbiota promotes the development of atherosclerosis by producing intermediate metabolites, including TMAO, LPS, PAGln and reducing butyrate. TMAO and PAGln might be potential biomarkers of coronary heart disease. Many studies have shown that butyrate-producing bacteria prevent atherosclerosis progression by producing butyrate and maintaining the bacterial balance, the intestinal barrier function and the expression of various genes, including those encoding lipids and those related to immunity, inflammation, differentiation, apoptosis, phagocytosis and efferocytosis. This review focuses on recent advances in our understanding of the interplay between butyrate-producing bacteria and the gut-heart axis in atherosclerosis.

Non-Coding RNAs as Regulators and Markers for Targeting of Breast Cancer and Cancer Stem Cells

Breast cancer is regarded as a heterogeneous and complicated disease that remains the prime focus in the domain of public health concern. Next-generation sequencing technologies provided a new perspective dimension to non-coding RNAs, which were initially considered to be transcriptional noise or a product generated from erroneous transcription. Even though understanding of biological and molecular functions of noncoding RNA remains enigmatic, researchers have established the pivotal role of these RNAs in governing a plethora of biological phenomena that includes cancer-associated cellular processes such as proliferation, invasion, migration, apoptosis, and stemness. In addition to this, the transmission of microRNAs and long non-coding RNAs was identified as a source of communication to breast cancer cells either locally or systemically. The present review provides in-depth information with an aim at discovering the fundamental potential of non-coding RNAs, by providing knowledge of biogenesis and functional roles of micro RNA and long non-coding RNAs in breast cancer and breast cancer stem cells, as either oncogenic drivers or tumor suppressors. Furthermore, non-coding RNAs and their potential role as diagnostic and therapeutic moieties have also been summarized.

USP15 potentiates NF-κB activation by differentially stabilizing TAB2 and TAB3

Tumor necrosis factor α (TNFα)- and interleukin 1β (IL-1β)-induced nuclear factor-κB (NF-κB) activation play key roles in inflammation, immunity, and cancer development. Here, we identified one of the deubiquitinating enzymes (DUBs), ubiquitin-specific protease 15 (USP15), as a positive regulator in both TNFα- and IL-1β-induced NF-κB activation. Overexpression of USP15 potentiated TNFα- or IL-1β-triggered NF-κB activation and downstream gene transcription, whereas knockdown of USP15 had opposite effects. Mechanistically, upon TNFα stimulation, USP15 showed an enhanced interaction with transforming growth factor-β activated kinase-1 (TAK1)-TAK1 binding protein (TAB) complex to inhibit the proteolysis of TAB2/3 by different pathways. Apart from deubiquitination dependently inducing cleavage of lysine 48-linked TAB2 ubiquitination, USP15 also DUB independently inhibited lysosome-associated TAB2 degradation, thus enhanced TAB2 stabilization. For TAB3, USP15 inhibited NBR1-mediated selective autophagic TAB3 degradation independent of its deubiquitinating activity. Together, our results reveal a novel USP15-mediated mechanism through which efficient NF-κB activation is achieved by differentially maintaining the TAB2/3 stability.

Role of microRNAs in remodeling the tumor microenvironment (Review)

MicroRNAs (miRNAs) are short non-coding RNAs that are known to regulate gene expression at the post-transcriptional level. miRNA expression is often deregulated in several human cancers, affecting the communication between tumor stroma and tumor cells, among other functions. Understanding the role of miRNAs in the tumor microenvironment is crucial for fully elucidating the molecular mechanisms underlying tumor progression and exploring novel diagnostic biomarkers and therapeutic targets. The present review focused on the role of miRNAs in remodeling the tumor microenvironment, with an emphasis on their impact on tumor growth, metastasis and resistance to treatment, as well as their potential clinical applications.

Effect of Beta-Blockade on the Expression of Regulatory MicroRNA after Severe Trauma and Chronic Stress

BACKGROUND

Beta-blockade administration after lung contusion, hemorrhagic shock, and chronic stress has been shown to improve bone marrow function, decrease hypercatecholaminemia, and reduce inflammation. MicroRNAs (miR) are critical biologic regulators that can downregulate gene expression by causing messenger RNA degradation or inhibition of translation. This study sought to expand our understanding of the molecular mechanisms underlying the reduced inflammatory response after the administration of beta-blockade (BB) in our rodent trauma model.

STUDY DESIGN

Male Sprague-Dawley rats aged 8 to 9 weeks were randomized to lung contusion, hemorrhagic shock with daily restraint stress (LCHS/CS) or LCHS/CS plus propranolol (LCHS/CS+BB). Restraint stress occurred 2 hours daily after LCHS. Propranolol (10 mg/kg) was given daily until day 7. Total RNA and miR were isolated from bone marrow and genome-wide miR expression patterns were assayed. Bone marrow cytokine expression was determined with quantitative polymerase chain reaction.

RESULTS

LCHS/CS led to significantly increased bone marrow expression of interleukin (IL) 1β, tumor necrosis factor-α, IL-6, nitric oxide, and plasma C-reactive protein. There were marked differences in expression of 45 miRs in the LCHS/CS+BB group compared with the LCHS/CS group when using a p value <0.001. Rno-miR-27a and miR-25 were upregulated 7- to 8-fold in the rodents who underwent LCHS/CS+BB compared with LCHS/CS alone, and this correlated with reduced bone marrow expression of IL-1β, tumor necrosis factor-α, IL-6, nitric oxide, and reduced plasma C-reactive protein in the LCHS/CS+BB group.

CONCLUSIONS

The genomic and miR expression patterns in bone marrow after LCHS/CS differed significantly compared with rodents that received propranolol after LCHS/CS. The use of BB after severe trauma can help mitigate persistent inflammation by upregulating Rno-miR-27a and miR-25 and reducing inflammatory cytokines in those who remain critically ill.

MicroRNA-27a (miR-27a) in Solid Tumors: A Review Based on Mechanisms and Clinical Observations

MicroRNAs (miRNAs) are a family of highly conserved, non-coding single-stranded RNAs transcribed as ~70 nucleotide precursors to an 18–22 nucleotide product (1). miRNAs can silence their homologous target genes at the post-transcriptional level, and these genes have been revealed to play an important role in tumorigenesis, invasion and metastasis (2). MicroRNA-27a (miR-27a), transcripted by miR-27a gene, has proved to implicate with many kinds of solid tumors, showing potential as a useful biomarker or drug target for clinical application. However, even though miR-27a has been reported in many cancers, the mechanism and signal pathways of miR-27 in oncogenesis, invasion, and metastasis are still obscure. Moreover, recent studies show that miR-27a pays an important role in epithelial-mesenchymal-transition, regulating tumor immune response, and chemoresistance. In this review, we summarize the current literature, demonstrate the established link between miR-27a and tumorigenesis, and focus on recently identified mechanisms. The review also aims to demonstrate the potential of miR-27a as a diagnostic and/or prognostic biomarker in solid tumors and to discuss the possibilities of targeted therapy and drug design.

Gut Microbiota Interventions With Clostridium butyricum and Norfloxacin Modulate Immune Response in Experimental Autoimmune Encephalomyelitis Mice

Gut microbiota has been proposed as an important environmental factor which can intervene and modulate central nervous system autoimmunity. Here, we altered the composition of gut flora with Clostridium butyricum and norfloxacin in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis. We found that appropriate C. butyricum (5.0 × 10⁶ CFU/mL intragastrically daily, staring at weaning period of age) and norfloxacin (5 mg/kg intragastrically daily, 1 week prior to EAE induction) treatment could both ameliorate EAE although there are obvious differences in gut microbiota composition between these two interventions. C. butyricum increased while norfloxacin decreased the abundance and diversity of the gut microbiota in EAE mice, and both of the treatments decreased firmicutes/bacteroidetes ratio. In the genus level, C. butyricum treatment increased the abundance of Prevotella while Akkermansia and Allobaculum increased in norfloxacin treatment. Moreover, both interventions reduced Desulfovibroneceae and Ruminococcus species. Although there was discrepancy in the gut microbiota composition with the two interventions, C. butyricum and norfloxacin treatment both reduced Th17 response and increased Treg response in the gastrointestinal tract and extra-gastrointestinal organ systems in EAE mice. And the reduced activity of p38 mitogen-activated kinase and c-Jun N-terminal kinase signaling in spinal cord could be observed in the two interventions. The results suggested that manipulation of gut microbiota interventions should take factors such as timing, duration, and dosage into consideration. The discrepancy in the gut microbiota composition and the similar protective T cells response of C. butyricum and norfloxacin implies that achieving intestinal microecology balance by promoting and/or inhibiting the gut microbiota contribute to the well-being of immune response in EAE mice.

Interactive functions of microRNAs in the miR-23a-27a-24-2 cluster and the potential for targeted therapy in cancer

MicroRNAs (miRNAs) are small noncoding RNAs about 19-22 nucleotides in length. Growing evidence has reported the significant role of miRNAs in various cancer-associated biological processes, such as proliferation, differentiation, apoptosis, metabolism, invasion, metastasis, and drug resistance. However, most studies focus on the targets of some individual miRNAs; the interactive and global functions of diverse miRNAs are still unclear and the phenomenon of the gathering of miRNAs in clusters has always been ignored. On the other hand, the fact that a single miRNA may regulate many genes and that numerous mRNAs are regulated by the same miRNA also makes it imperative to further study the cooperating characteristics of miRNAs in cancer. MiR-23a-27a-24-2 is located in the human chromosome 9q22, forming three mature miRNAs: miR-23a, miR27a, and miR-24, which are expressed abnormally in many malignant tumors. This review aims to summarize the interactive functions of miRNAs in miR-23a-27a-24-2 clusters in cancer from the perspectives of the regulation network, tumor microenvironment, and targeted therapy.

Systems biology reveals how altered TGFβ signalling with age reduces protection against pro-inflammatory stimuli

Osteoarthritis (OA) is a degenerative condition caused by dysregulation of multiple molecular signalling pathways. Such dysregulation results in damage to cartilage, a smooth and protective tissue that enables low friction articulation of synovial joints. Matrix metalloproteinases (MMPs), especially MMP-13, are key enzymes in the cleavage of type II collagen which is a vital component for cartilage integrity. Transforming growth factor beta (TGFβ) can protect against pro-inflammatory cytokine-mediated MMP expression. With age there is a change in the ratio of two TGFβ type I receptors (Alk1/Alk5), a shift that results in TGFβ losing its protective role in cartilage homeostasis. Instead, TGFβ promotes cartilage degradation which correlates with the spontaneous development of OA in murine models. However, the mechanism by which TGFβ protects against pro-inflammatory responses and how this changes with age has not been extensively studied. As TGFβ signalling is complex, we used systems biology to combine experimental and computational outputs to examine how the system changes with age. Experiments showed that the repressive effect of TGFβ on chondrocytes treated with a pro-inflammatory stimulus required Alk5. Computational modelling revealed two independent mechanisms were needed to explain the crosstalk between TGFβ and pro-inflammatory signalling pathways. A novel meta-analysis of microarray data from OA patient tissue was used to create a Cytoscape network representative of human OA and revealed the importance of inflammation. Combining the modelled genes with the microarray network provided a global overview into the crosstalk between the different signalling pathways involved in OA development. Our results provide further insights into the mechanisms that cause TGFβ signalling to change from a protective to a detrimental pathway in cartilage with ageing. Moreover, such a systems biology approach may enable restoration of the protective role of TGFβ as a potential therapy to prevent age-related loss of cartilage and the development of OA.

MiRNAs and inflammatory bowel disease: An interesting new story

Inflammatory bowel disease (IBD), as a chronic and recurrent inflammatory disorder, is caused by a dysregulated and aberrant immune response to exposed environmental factors in genetically susceptible individuals. Despite huge efforts in determining the molecular pathogenesis of IBD, an increasing worldwide incidence of IBD has been reported. MicroRNAs (miRNAs) are a set of noncoding RNA molecules that are about 22 nucleotides long, and these molecules are involved in the regulation of the gene expression. By clarifying the important role of miRNAs in a number of diseases, their role was also considered in IBD; numerous studies have been performed on this topic. In this review, we attempt to summarize a number of studies and discuss some of the recent developments in the roles of miRNAs in the pathophysiology, diagnosis, and treatment of IBD.

MiR27a Promotes the Development of Macrophage-like Characteristics in 3T3-L1 Preadipocytes

Recruitment and polarization of classically activated (M1) macrophages within adipose tissue contribute to chronic low-grade inflammation in obesity. Adipose tissue precursor cells exhibit the capacity to develop macrophage-like characteristics and adipocyte-derived miR27a is known to promote reprogramming of somatic cells. It was unknown whether exogenous addition of miR27a promote the development of macrophage-like characteristics of adipose precursor cells. We examined macrophage surface antigen, phagocytosis and migration ability in 3T3-L1 preadipocytes transfected with miR27a mimics. Transfection of 3T3-L1 preadipocytes with miR27a mimics increased phagocytosis and migration and increased the number of cells expressing the macrophage makers F4/80 and MHC compared to controls. M2 and CD206 macrophage markers were unaltered. In addition, transfection of 3T3-L1 preadipocytes with miR27a mimics reduced PPARγ expression, activated NF-κB and promoted secretion of the inflammatory cytokines MCP-1, TNF-α and IL-1β compared to controls. The level of anti-inflammatory factors Arg-1, IL-10, Ym1 and Fizz1 were unaltered. Secretion of miR27a was increased in conditioned medium prepared from palmitic acid-treated differentiated 3T3-L1 adipocytes compared to controls. Incubation of 3T3-L1 preadipocytes with this conditioned medium increased phagocytosis and migration compared to controls. Finally, conditioned medium prepared from differentiated 3T3-L1 adipocytes transfection with miR27a inhibitors reduced phagocytosis and migration in 3T3-L1 preadipocytes compared to controls. The data indicate that PPARγ agonists may reverse the activation of NF-κB pathway mediated by miR27a overexpression and reduce phagocytosis and migration of adipose precursor cells. In addition, miR27a may promote the development of macrophage-like characteristics in 3T3-L1 preadipocytes.

MiRNAs: dynamic regulators of immune cell functions in inflammation and cancer

MicroRNAs (miRNAs), small noncoding RNA molecules, have emerged as important regulators of almost all cellular processes. By binding to specific sequence motifs within the 3'- untranslated region of their target mRNAs, they induce either mRNA degradation or translational repression. In the human immune system, potent miRNAs and miRNA-clusters have been discovered, that exert pivotal roles in the regulation of gene expression. By targeting cellular signaling hubs, these so-called immuno-miRs have fundamental regulative impact on both innate and adaptive immune cells in health and disease. Importantly, they also act as mediators of tumor immune escape. Secreted by cancer cells and consecutively taken up by immune cells, immuno-miRs are capable to influence immune functions towards a blunted anti-tumor response, thus shaping a permissive tumor environment. This review provides an overview of immuno-miRs and their functional impact on individual immune cell entities. Further, implications of immuno-miRs in the amelioration of tumor surveillance are discussed.

In silico identification of microRNAs predicted to regulate N-myristoyltransferase and Methionine Aminopeptidase 2 functions in cancer and infectious diseases

Protein myristoylation is a key protein modification carried out by N-Myristoyltransferase (NMT) after Methionine aminopeptidase 2 (MetAP2) removes methionine from the amino-terminus of the target protein. Protein myristoylation by NMT augments several signaling pathways involved in a myriad of cellular processes, including developmental pathways and pathways that when dysregulated lead to cancer or immune dysfunction. The emerging evidence pointing to NMT-mediated myristoylation as a major cellular regulator underscores the importance of understanding the framework of this type of signaling event. Various studies have investigated the role that myristoylation plays in signaling dysfunction by examining differential gene or protein expression between normal and diseased states, such as cancers or following HIV-1 infection, however no study exists that addresses the role of microRNAs (miRNAs) in the regulation of myristoylation. By performing a large scale bioinformatics and functional analysis of the miRNAs that target key genes involved in myristoylation (NMT1, NMT2, MetAP2), we have narrowed down a list of promising candidates for further analysis. Our condensed panel of miRNAs identifies 35 miRNAs linked to cancer, 21 miRNAs linked to developmental and immune signaling pathways, and 14 miRNAs linked to infectious disease (primarily HIV). The miRNAs panel that was analyzed revealed several NMT-targeting mRNAs (messenger RNA) that are implicated in diseases associated with NMT signaling alteration, providing a link between the realms of miRNA and myristoylation signaling. These findings verify miRNA as an additional facet of myristoylation signaling that must be considered to gain a full perspective. This study provides the groundwork for future studies concerning NMT-transcript-binding miRNAs, and will potentially lead to the development of new diagnostic/prognostic biomarkers and therapeutic targets for several important diseases.

Plasma MicroRNA Profiles in Patients with Early Rheumatoid Arthritis Responding to Adalimumab plus Methotrexate vs Methotrexate Alone: A Placebo-controlled Clinical Trial

OBJECTIVE

The aim was to identify plasma (i.e., cell-free) microRNA (miRNA) predicting antitumor necrosis and/or methotrexate (MTX) treatment response in patients enrolled in an investigator-initiated, prospective, double-blinded, placebo-controlled trial (The OPERA study, NCT00660647).

METHODS

We included 180 disease-modifying antirheumatic drug-naive patients with early rheumatoid arthritis (RA) randomized to adalimumab (ADA; n = 89) or placebo (n = 91) in combination with MTX. Plasma samples before and 3 months after treatment initiation were analyzed for 91 specific miRNA by quantitative reverse transcriptase-polymerase chain reaction on microfluidic dynamic arrays. A linear mixed-effects model was used to test for associations between pretreatment miRNA and changes in miRNA expression and American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean (28 joints) remission at 3 and 12 months, applying false discovery rate correction for multiple testing. Using leave-one-out cross validation, we built predictive multivariate miRNA models and estimated classification performances using receiver-operating characteristics (ROC) curves.

RESULTS

In the ADA group, a higher pretreatment level of miR-27a-3p was significantly associated with remission at 12 months. The level decreased in remitting patients between pretreatment and 3 months, and increased in nonremitting patients. No associations were found in the placebo group receiving only MTX. Two multivariate miRNA models were able to predict response to ADA treatment after 3 and 12 months, with 63% and 82% area under the ROC curves, respectively.

CONCLUSION

We identified miR-27a-3p as a potential predictive biomarker of ACR/EULAR remission in patients with early RA treated with ADA in combination with MTX. We conclude that pretreatment plasma-miRNA profiles may be of predictive value, but the results need confirmation in independent cohorts.

TGF-β, Bone Morphogenetic Protein, and Activin Signaling and the Tumor Microenvironment

The cellular and noncellular components surrounding the tumor cells influence many aspects of tumor progression. Transforming growth factor β (TGF-β), bone morphogenetic proteins (BMPs), and activins have been shown to regulate the phenotype and functions of the microenvironment and are attractive targets to attenuate protumorigenic microenvironmental changes. Given the pleiotropic nature of the cytokines involved, a full understanding of their effects on numerous cell types in many contexts is necessary for proper clinical intervention. In this review, we will explore the various effects of TGF-β, BMP, and activin signaling on stromal phenotypes known to associate with cancer progression. We will summarize these findings in the context of their tumor suppressive or promoting effects, as well as the molecular changes that these cytokines induce to influence stromal phenotypes.

Androgen-induced miR-27A acted as a tumor suppressor by targeting MAP2K4 and mediated prostate cancer progression

Prostate cancer (PCa) is the most commonly diagnosed and secondly leading cause of cancer death among males. But the precise mechanism of prostate cancer progression, including microRNAs (miRNAs) functioning in it, is still needs further study. We found miR-27a to be down-regulated in prostate cancer, and we investigated the mechanism and role of miRNA-27a in prostate cancer. MiR-27a, a transcriptional target of AR, was an androgen-induced miRNA in LNCaP cells. In castration-resistant prostate cancer (CRPC) cells, we for the first time reported that miR-27a was downregulated by PI3K signaling. MiR-27a functioned as a tumor suppressor in prostate cancer. Over-expression of miR-27a decreased prostate cancer cell proliferation and migration, and induced prostate cancer cell cycle arrest and apoptosis. MAP2K4, miR-27a's direct target gene, functioned as an oncogene in prostate cancer by reducing G1-S phase arrest and inhibiting cell apoptosis of prostate cancer cells. In conclusion, miR-27a functions as a tumor suppressor by suppressing MAP2K4 which acts as an oncogene in prostate cancer cell lines; we also provided a new mechanism of castration-resistant prostate cancer mediated by miR-27a that downregulation of miR-27a caused by aberrant AR signaling and PI3K/Akt signaling after androgen deprivation therapy (ADT) would promote the progression of castration-resistant prostate cancer.

Comprehensive evaluation of serum microRNAs as biomarkers in multiple sclerosis

Objective:

To identify circulating microRNAs (miRNAs) linked to disease stage and disability in multiple sclerosis (MS).

Methods:

Sera from 296 participants including patients with MS, other neurologic diseases (Alzheimer disease and amyotrophic lateral sclerosis), and inflammatory diseases (rheumatoid arthritis and asthma) and healthy controls (HCs) were tested. miRNA profiles were determined using LNA (locked nucleic acid)-based quantitative PCR. Patients with MS were categorized according to disease stage and disability. In the discovery phase, 652 miRNAs were measured in sera from 26 patients with MS and 20 HCs. Following this, significant miRNAs (p < 0.05) from the discovery set were validated using quantitative PCR in 58 patients with MS, 30 HCs, and in 74 samples from other disease controls (Alzheimer disease, amyotrophic lateral sclerosis, asthma, and rheumatoid arthritis).

Results:

We validated 7 miRNAs that differentiate patients with MS from HCs (p < 0.05 in both the discovery and validation phase); miR-320a upregulation was the most significantly changing serum miRNA in patients with MS. We also identified 2 miRNAs linked to disease progression, with miR-27a-3p being the most significant. Ten miRNAs correlated with the Expanded Disability Status Scale of which miR.199a.5p had the strongest correlation with disability. Of the 15 unique miRNAs we identified in the different group comparisons, 12 have previously been reported to be associated with MS but not in serum.

Conclusions:

Our findings identify circulating serum miRNAs as potential biomarkers to diagnose and monitor disease status in MS.

Classification of evidence:

This study provides Class III evidence that circulating serum miRNAs can be used as biomarker for MS.

MicroRNA-27a Negatively Modulates the Inflammatory Response in Lipopolysaccharide-Stimulated Microglia by Targeting TLR4 and IRAK4

microRNA, a family of small non-coding RNA, plays significant roles in regulating gene expression, mainly via binding to the 3'-untranslated region of target genes. Although the role of miRNA in regulating neuroinflammation via the innate immune pathway has been studied, its role in the production of inflammatory mediators during microglial activation is poorly understood. In this study, we investigated the effect of miR-27a on lipopolysaccharide (LPS)-induced microglial inflammation. miR-27a expression was found to be rapidly decreased in microglia by real-time polymerase chain reaction (real-time PCR) after LPS stimulation. Over-expression of miR-27a significantly decreased the production of inflammatory cytokines, such as interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and nitric oxide (NO), whereas knockdown of miR-27a increased the expression of these inflammatory factors. We also demonstrated by loss- and gain-of-function studies that miR-27a directly suppressed the expression of toll-like receptor 4 (TLR4) and interleukin-1 receptor-associated kinase 4 (IRAK4)-a pivotal adaptor kinase in the TLR4/MyD88 signaling pathway-by directly binding their 3'-UTRs: knocking down TLR4 or IRAK4 in microglia significantly decreased TLR4 or IRAK4 expression and inhibited the downstream production of inflammatory mediators. Moreover, the inflammatory cytokines IL-6 and IL-1β were regulated by IRAK4, whereas TNF-α and NO were more dependent on TLR4 activation. Thus, miR-27a might regulate the LPS-induced production of inflammatory cytokines in microglia independently of TLR4 and IRAK4. Taken together, our results suggest that miR-27a is associated with microglial activation and the inflammatory response.

Proteomic screening identifies calreticulin as a miR-27a direct target repressing MHC class I cell surface exposure in colorectal cancer

Impairment of the immune response and aberrant expression of microRNAs are emerging hallmarks of tumour initiation/progression, in addition to driver gene mutations and epigenetic modifications. We performed a preliminary survey of independent adenoma and colorectal cancer (CRC) miRnoma data sets and, among the most dysregulated miRNAs, we selected miR-27a and disclosed that it is already upregulated in adenoma and further increases during the evolution to adenocarcinoma. To identify novel genes and pathways regulated by this miRNA, we employed a differential 2DE-DIGE proteome analysis. We showed that miR-27a modulates a group of proteins involved in MHC class I cell surface exposure and, mechanistically, demonstrated that calreticulin is a miR-27a direct target responsible for most downstream effects in epistasis experiments. In vitro miR-27a affected cell proliferation and angiogenesis; mouse xenografts of human CRC cell lines expressing different miR-27a levels confirmed the protein variations and recapitulated the cell growth and apoptosis effects. In vivo miR-27a inversely correlated with MHC class I molecules and calreticulin expression, CD8⁺ T cells infiltration and cytotoxic activity (LAMP-1 exposure and perforin release). Tumours with high miR-27a, low calreticulin and CD8⁺ T cells' infiltration were associated with distant metastasis and poor prognosis. Our data demonstrate that miR-27a acts as an oncomiRNA, represses MHC class I expression through calreticulin downregulation and affects tumour progression. These results may pave the way for better diagnosis, patient stratification and novel therapeutic approaches.

miRNA Deregulation in Cancer Cells and the Tumor Microenvironment

miRNAs are a key component of the noncoding RNA family. The underlying mechanisms involved in the interplay between the tumor microenvironment and cancer cells involve highly dynamic factors such as hypoxia and cell types such as cancer-associated fibroblasts and macrophages. Although miRNA levels are known to be altered in cancer cells, recent evidence suggests a critical role for the tumor microenvironment in regulating miRNA biogenesis, methylation, and transcriptional changes. Here, we discuss the complex protumorigenic symbiotic role between tumor cells, the tumor microenvironment, and miRNA deregulation.

SIGNIFICANCE

miRNAs play a central role in cell signaling and homeostasis. In this article, we provide insights into the regulatory mechanisms involved in the deregulation of miRNAs in cancer cells and the tumor microenvironment and discuss therapeutic intervention strategies to overcome this deregulation.

miR-23∼27∼24 clusters control effector T cell differentiation and function

The miR-23∼27∼24 clusters control differentiation of effector T cells. In particular, miR-24 targets IL-4 and miR-27 targets GATA3, thus collaborating in the control of Th2 immunity.

Coordinated repression of gene expression by evolutionarily conserved microRNA (miRNA) clusters and paralogs ensures that miRNAs efficiently exert their biological impact. Combining both loss- and gain-of-function genetic approaches, we show that the miR-23∼27∼24 clusters regulate multiple aspects of T cell biology, particularly helper T (Th) 2 immunity. Low expression of this miRNA family confers proper effector T cell function at both physiological and pathological settings. Further studies in T cells with exaggerated regulation by individual members of the miR-23∼27∼24 clusters revealed that miR-24 and miR-27 collaboratively limit Th2 responses through targeting IL-4 and GATA3 in both direct and indirect manners. Intriguingly, although overexpression of the entire miR-23 cluster also negatively impacts other Th lineages, enforced expression of miR-24, in contrast to miR-23 and miR-27, actually promotes the differentiation of Th1, Th17, and induced regulatory T cells, implying that under certain conditions, miRNA families can fine tune the biological effects of their regulation by having individual members antagonize rather than cooperate with each other. Together, our results identify a miRNA family with important immunological roles and suggest that tight regulation of miR-23∼27∼24 clusters in T cells is required to maintain optimal effector function and to prevent aberrant immune responses.

MicroRNAs, TGF-β signaling, and the inflammatory microenvironment in cancer

Inflammatory cells and mediators form a major part of the tumor microenvironment and play important roles in the regulation of cancer initiation, tumor cell proliferation, and metastasis. MicroRNAs (miRNAs) play important roles in several physiological and pathological processes, including the regulation of the inflammatory microenvironment in cancer. Transforming growth factor-β (TGF-β) is an inflammation-related cytokine that functions in both tumor suppression and promotion; however, its underlying molecular mechanisms remain unclear. Recent evidence indicates an association between miRNAs and TGF-β signaling, providing new insight into the nature of the inflammatory microenvironment in cancer. The present review is an overview of the interaction between miRNAs and inflammatory cytokines, with emphasis on the cross talk between TGF-β signaling and miRNAs and their influence on cancer cell behavior. The emerging roles of miRNAs in cancer-related inflammation and the potential to target miRNA signaling pathways for cancer therapy are also discussed.

Regulatory dendritic cells in autoimmunity: A comprehensive review. J Autoimmun. 2015;63:1-12. [PMID: 26255250 DOI: 10.1016/j.jaut.2015.07.011]

Dendritic cells (DCs) are professional antigen-presenting cells (APC) with significant phenotypic heterogeneity and functional plasticity. DCs play crucial roles in initiating effective adaptive immune responses for elimination of invading pathogens and also in inducing immune tolerance toward harmless components to maintain immune homeostasis. The regulatory capacity of DCs depends on their immature state and distinct subsets, yet not restricted to the immature state and one specialized subset. The tolerogenicity of DC is controlled by a complex network of environmental signals and cellular intrinsic mechanisms. Regulatory DCs play an important role in the maintenance of immunological tolerance via the induction of T cell unresponsiveness or apoptosis, and generation of regulatory T cells. DCs play essential roles in driving autoimmunity via promoting the activation of effector T cells such as T helper 1 and T helper 17 cells, and/or suppressing the generation of regulatory T cells. Besides, a breakdown of DCs-mediated tolerance due to abnormal environmental signals or breakdown of intrinsic regulatory mechanisms is closely linked with the pathogenesis of autoimmune diseases. Novel immunotherapy taking advantage of the tolerogenic potential of regulatory DCs is being developed for treatment of autoimmune diseases. In this review, we will describe the current understanding on the generation of regulatory DC and the role of regulatory DCs in promoting tolerogenic immune responses and suppressing autoimmune responses. The emerging roles of DCs dysfunction in the pathogenesis of autoimmune diseases and the potential application of regulatory DCs in the treatment of autoimmune diseases will also be discussed.

Alcohol-induced miR-27a regulates differentiation and M2 macrophage polarization of normal human monocytes

Alcohol abuse is a leading cause of liver disease characterized by liver inflammation, fatty liver, alcoholic hepatitis, or liver cirrhosis. Immunomodulatory effects of alcohol on monocytes and macrophages contribute to alcoholic liver disease. Alcohol use, an independent risk factor for progression of hepatitis C virus (HCV) infection-mediated liver disease, impairs host defense and alters cytokine production and monocyte/macrophage activation. We hypothesized that alcohol and HCV have synergistic effects on the phenotype and function of monocytes. Our data show that acute alcohol binge drinking in healthy volunteers results in increased frequency of CD16(+) and CD68(+) and M2-type (CD206(+), dendritic cell [DC]-SIGN(+)-expressing and IL-10-secreting) circulating CD14(+) monocytes. Expression of HCV-induced CD68 and M2 markers (CD206 and DC-SIGN) in normal monocytes was further enhanced in the presence of alcohol. The levels of microRNA (miR)-27a was significantly upregulated in monocytes cultured in the presence of alcohol or alcohol and HCV as compared with HCV alone. The functional role of miR-27a in macrophage polarization was demonstrated by transfecting monocytes with an miR-27a inhibitor that resulted in reduced alcohol- and HCV- mediated monocyte activation (CD14 and CD68 expression), polarization (CD206 and DC-SIGN expression), and IL-10 secretion. Overexpression of miR-27a in monocytes enhanced IL-10 secretion via activation of the ERK signaling pathway. We found that miR-27a promoted ERK phosphorylation by downregulating the expression of ERK inhibitor sprouty2 in monocytes. Thus, we identified that sprouty2 is a target of miR-27a in human monocytes. In summary, our study demonstrates the regulatory role of miR-27a in alcohol-induced monocyte activation and polarization.

Interleukin-10 receptor-1 expression in monocyte-derived antigen-presenting cell populations: dendritic cells partially escape from IL-10's inhibitory mechanisms

Interleukin (IL)-10 is an important immunoregulatory cytokine that mediates its effects via a transmembrane receptor complex consisting of two different chains, IL-10R1 and IL-10R2. While IL-10R2 is ubiquitously expressed and does not bind IL-10 primarily, the expression of IL-10R1 determines cellular responsiveness. However, the current knowledge about the expression and regulation of IL-10R1 is still limited. Here we analyzed the expression of IL-10R1 on monocytic cells and demonstrated that human blood monocytes carried about 720 IL-10-binding sites on their surface. Compared with lymphocytes and various tissue cells and tissues, blood monocytes expressed the highest IL-10R1 levels. The in vitro differentiation of these cells into macrophages provoked a further increase of IL-10R1 surface expression. In contrast, their differentiation into myeloid dendritic cells (mDCs) resulted in reduced surface IL-10R1 levels. The different IL-10R1 levels expressed by monocyte-derived antigen-presenting cell populations were reflected in their different responsiveness toward IL-10. Importantly, also in vivo developed immature macrophages and mDCs showed different IL-10 sensitivity. These data suggest that, compared with monocytes and macrophages, mDCs partially escape from IL-10's inhibitory mechanisms by downregulating IL-10R1.

Retroviral infection of murine embryonic stem cell derived embryoid body cells for analysis of hematopoietic differentiation

Embryonic stem cells (ESCs) are an outstanding model for elucidating the molecular mechanisms of cellular differentiation. They are especially useful for investigating the development of early hematopoietic progenitor cells (HPCs). Gene expression in ESCs can be manipulated by several techniques that allow the role for individual molecules in development to be determined. One difficulty is that expression of specific genes often has different phenotypic effects dependent on their temporal expression. This problem can be circumvented by the generation of ESCs that inducibly express a gene of interest using technology such as the doxycycline-inducible transgene system. However, generation of these inducible cell lines is costly and time consuming. Described here is a method for disaggregating ESC-derived embryoid bodies (EBs) into single cell suspensions, retrovirally infecting the cell suspensions, and then reforming the EBs by hanging drop. Downstream differentiation is then evaluated by flow cytometry. Using this protocol, it was demonstrated that exogenous expression of a microRNA gene at the beginning of ESC differentiation blocks HPC generation. However, when expressed in EB derived cells after nascent mesoderm is produced, the microRNA gene enhances hematopoietic differentiation. This method is useful for investigating the role of genes after specific germ layer tissue is derived.

Myeloid-derived microRNAs, miR-223, miR27a, and miR-652, are dominant players in myeloid regulation

In the past few years expanding knowledge has been accumulated about the role of microRNAs (miRNAs) not only in hematopoiesis and cancer, but also in inflammatory and infectious diseases. Regarding myeloid cells, our knowledge is relatively insufficient, therefore we intended to collect the available data of miRNA profiles of myeloid cells. In addition to a rather general myeloid regulator miR-223, two other miRNAs seem to be useful subjects in understanding of myeloid miRNA biology: miR-27a and miR-652. We review functions of these three miRNAs and other myeloid miRNAs focusing on their roles in monocytes, neutrophils, eosinophils, basophils and mast cells.

miRNomes of haematopoietic stem cells and dendritic cells identify miR-30b as a regulator of Notch1

Dendritic cells (DCs) are critical to initiate the immune response and maintain tolerance, depending on different status and subsets. The expression profiles of microRNAs (miRNAs) in various DC subsets and haematopoietic stem cells (HSCs), which generate DCs, remain to be fully identified. Here we examine miRNomes of mouse bone marrow HSCs, immature DCs, mature DCs and IL-10/NO-producing regulatory DCs by deep sequencing. We identify numerous stage-specific miRNAs and histone modification in HSCs and DCs at different differentiation stages. miR-30b, significantly upregulated via a TGF-beta/Smad3-mediated epigenetic pathway in regulatory DCs, can target Notch1 to promote IL-10 and NO production, suggesting that miR-30b is a negative regulator of immune response. We also identify miRNomes of in vivo counterparts of mature DCs and regulatory DCs and systematically compare them with DCs cultured in vitro. These results provide a resource for studying roles of miRNAs in stem cell biology, development and functional regulation of DC subsets.