Bruton's tyrosine kinase is involved in miR-346-related regulation of IL-18 release by lipopolysaccharide-activated rheumatoid fibroblast-like synoviocytes

Bioengineering strategies to enhance the interleukin-18 bioactivity in the modern toolbox of cancer immunotherapy

Cytokines are the first modern immunotherapeutic agents used for activation immunotherapy. Interleukin-18 (IL-18) has emerged as a potent anticancer immunostimulatory cytokine over the past three decades. IL-18, structurally is a stable protein with very low toxicity at biological doses. IL-18 promotes the process of antigen presentation and also enhances innate and acquired immune responses. It can induce the production of proinflammatory cytokines and increase tumor infiltration of effector immune cells to revert the immunosuppressive milieu of tumors. Furthermore, IL-18 can reduce tumorigenesis, suppress tumor angiogenesis, and induce tumor cell apoptosis. These characteristics present IL-18 as a promising option for cancer immunotherapy. Although several preclinical studies have reported the immunotherapeutic potential of IL-18, clinical trials using it as a monotherapy agent have reported disappointing results. These results may be due to some biological characteristics of IL-18. Several bioengineering approaches have been successfully used to correct its defects as a bioadjuvant. Currently, the challenge with this anticancer immunotherapeutic agent is mainly how to use its capabilities in a rational combinatorial therapy for clinical applications. The present study discussed the strengths and weaknesses of IL-18 as an immunotherapeutic agent, followed by comprehensive review of various promising bioengineering approaches that have been used to overcome its disadvantages. Finally, this study highlights the promising application of IL-18 in modern combinatorial therapies, such as chemotherapy, immune checkpoint blockade therapy, cell-based immunotherapy and cancer vaccines to guide future studies, circumventing the barriers to administration of IL-18 for clinical applications, and bring it to fruition as a potent immunotherapy agent in cancer treatment.

Comprehensive overview of microRNA function in rheumatoid arthritis

MicroRNAs (miRNAs), a class of endogenous single-stranded short noncoding RNAs, have emerged as vital epigenetic regulators of both pathological and physiological processes in animals. They direct fundamental cellular pathways and processes by fine-tuning the expression of multiple genes at the posttranscriptional level. Growing evidence suggests that miRNAs are implicated in the onset and development of rheumatoid arthritis (RA). RA is a chronic inflammatory disease that mainly affects synovial joints. This common autoimmune disorder is characterized by a complex and multifaceted pathogenesis, and its morbidity, disability and mortality rates remain consistently high. More in-depth insights into the underlying mechanisms of RA are required to address unmet clinical needs and optimize treatment. Herein, we comprehensively review the deregulated miRNAs and impaired cellular functions in RA to shed light on several aspects of RA pathogenesis, with a focus on excessive inflammation, synovial hyperplasia and progressive joint damage. This review also provides promising targets for innovative therapies of RA. In addition, we discuss the regulatory roles and clinical potential of extracellular miRNAs in RA, highlighting their prospective applications as diagnostic and predictive biomarkers.

Tumor suppressor LHX6 upregulation contributes to the inhibitory effect of miR-346 knockdown on colorectal cancer cell growth

Colorectal cancer (CRC) is one of the prevalent types of human malignancies and ranks as the second leading cause of cancer-associated death worldwide. Dysregulated miRNAs have been promulgated as oncogenes or tumor-suppressive genes participating in the initiation and progression of CRC. A recent study reported that miR-346 was highly expressed in CRC patients. However, the biological role and underlying mechanism of miR-346 in CRC remain elusive. qRT-PCR and western blot assays were employed to detect miR-346 and LIM homeobox domain 6 (LHX6) expression in CRC cells. Cell proliferation was evaluated by CCK-8 and BrdU assays. Apoptosis was evaluated by TUNEL assay. The interaction between miR-346 and LHX6 was assessed by luciferase reporter assay. Results showed that miR-346 expression was increased and LHX6 expression was reduced in CRC cells. miR-346 knockdown and LHX6 overexpression inhibited proliferation and promoted apoptosis of CRC cells. Additionally, we found that miR-346 negatively regulated LHX6 expression in CRC cells by directly targeting LHX6. LHX6 knockdown partially attenuated anti-miR-346-induced proliferation reduction and apoptosis promotion in CRC cells. Furthermore, miR-346 knockdown inhibited the protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) pathway in CRC cells by targeting LHX6. The present study indicated that miR-346 knockdown repressed cell growth in CRC cells by upregulating LHX6, and this was associated with inactivation of the Akt/mTOR pathway.

Micro RNA-23b as a potential biomarker in rheumatoid arthritis disease activity and severity: clinical, laboratory, and radiological cross-sectional study

Background

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease. It is characterized by an inflammatory polyarthritis that preferentially affects the small joints leading to joint damage and eventual deformity and disability, and can also present with extra-articular manifestations. Micro RNA (miRNA) is a class of non-coding RNAs which negatively regulate messenger RNA (mRNA) expression. Several studies had shown that miRNA-23b has a close relationship with inflammation and autoimmune diseases. An increasing evidence has suggested that miRNA-23b is closely associated with many inflammatory and autoimmune diseases. The current study aimed to evaluate the plasma expression of miRNA-23b in rheumatoid arthritis (RA) patients and to explore its potential association with diseases activity.

Results

RA patients had a significantly higher plasma miRNA-23b expression than controls (P < 0.001). The miRNA-23b plasma expression was significantly associated with the clinical and laboratory indices of RA activity as well as with the DAS28-ESR score (P = 0.009) and grades (P < 0.001). The miRNA-23b plasma expression was significantly correlated with the radiological severity of RA (P = 0.002).

Conclusions

Plasma expression of miRNA-23b is significantly increased in patients with RA than controls. In RA patients, plasma expression of miRNA-23b was significantly correlated with the activity and radiological severity of RA. miRNA-23b may represent a potential therapeutic target that can retard progression of RA.

Ginkgolide J protects human synovial cells SW982 via suppression of p38‑dependent production of pro‑inflammatory mediators

Fibroblast-like synoviocytes (FLS) in the synovial lining play a key role in the pathological process of rheumatoid arthritis (RA), which produce pro-inflammatory mediators to perpetuate inflammation and proteases to contribute to cartilage destruction. Ginkgolide J (GJ) is a subclass of ginkgolides (GGs) that exhibits anti-inflammatory activity. In the present study, the protective effect of GJ on lipopolysaccharide (LPS)-treated human synovial cells SW982 and its related mechanisms were investigated using various methods, including ELISA, Griess assay, western blotting, immunofluorescence analysis and p38 kinase activity assay. The results revealed that GJ pretreatment significantly attenuated LPS-induced excess production of pro-inflammatory mediators in SW982 cells via suppression of tumor necrosis factor-α/interleukin (IL)-1β/IL-18/NF-κB/NLR family pyrin domain containing 3, prostaglandin E2/cyclooxygenase-2 and inducible nitric oxide synthase/nitric oxide signaling. Mechanistic studies revealed that p38 activation contributed to the LPS-induced inflammatory response, and GJ pretreatment dose-dependently attenuated p38 activation, indicating that the suppressive effect of GJ was achieved by targeting p38 signaling. These findings may contribute to the prevention and treatment of RA.

The miRNA: a small but powerful RNA for COVID-19

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a severe and rapidly evolving epidemic. Now, although a few drugs and vaccines have been proved for its treatment and prevention, little systematic comments are made to explain its susceptibility to humans. A few scattered studies used bioinformatics methods to explore the role of microRNA (miRNA) in COVID-19 infection. Combining these timely reports and previous studies about virus and miRNA, we comb through the available clues and seemingly make the perspective reasonable that the COVID-19 cleverly exploits the interplay between the small miRNA and other biomolecules to avoid being effectively recognized and attacked from host immune protection as well to deactivate functional genes that are crucial for immune system. In detail, SARS-CoV-2 can be regarded as a sponge to adsorb host immune-related miRNA, which forces host fall into dysfunction status of immune system. Besides, SARS-CoV-2 encodes its own miRNAs, which can enter host cell and are not perceived by the host's immune system, subsequently targeting host function genes to cause illnesses. Therefore, this article presents a reasonable viewpoint that the miRNA-based interplays between the host and SARS-CoV-2 may be the primary cause that SARS-CoV-2 accesses and attacks the host cells.

MicroRNAs as Regulators of Immune and Inflammatory Responses: Potential Therapeutic Targets in Diabetic Nephropathy

Diabetic nephropathy (DN) is the principal cause of end-stage renal disease and results in high morbidity and mortality in patients, causing a large socioeconomic burden. Multiple factors, such as metabolic abnormalities, inflammation, immunoregulation and genetic predisposition, contribute to the pathogenesis of DN, but the exact mechanism is unclear, and the therapeutic strategies are not satisfactory. Accordingly, there is an unmet need for new therapeutic targets and strategies for DN. MicroRNAs (miRNAs) act as major epigenetic mechanisms that regulate gene expression and provide novel insights into our understanding of the molecular and signaling pathways that are associated with various diseases, including DN. Studies in the past decade have shown that different miRNAs affect the progression of DN by modulating different aspects of immune and inflammatory responses. Therefore, in this review, we summarized the pivotal roles of miRNAs in inflammatory and immune processes, with an integrative comprehension of the detailed signaling network. Additionally, we discussed the possibilities and significance of these miRNAs as therapeutic targets in the treatment of DN. This review will facilitate the identification of new therapeutic targets and novel strategies that can be translated into clinical applications for DN treatment.

Nociceptive related microRNAs and their role in rheumatoid arthritis

Rheumatoid Arthritis (RA) is an autoimmune disease with unknown etiology and a global incidence around 1%, a positive family history increases the risk of RA roughly three to five times. Pain is one of the first symptoms to appear in this disease. MicroRNAs (miRNAs) belong to the class of small non-coding RNAs; they regulate multiple cellular processes including embryonic development, cellular proliferation, differentiation and apoptosis among others. A great deal of evidence points to the employment of miRNAs as therapeutic targets and biomarkers for several pathologies. The main objective of this Review is to assess how miRNAs participate in the pathogenesis of RA. Two advanced searches were conducted in databases, one using "micro-RNA" and "rheumatoid arthritis" as key words, and another one with "micro-RNA", "pain" and "nociception". In this Review, we describe how six miRNAs: miR-16-5p, miR-23b-3b, miR-124-3p, miR-146a-5p, miR-155-5p and miR-223-3p, involved in the modulation and transmission of the nociceptive input are unregulated in RA patients. Key molecular pathways involved in nociception, inflammation and autoimmune responses, are regulated by these miRNAs; the NF-κB, TNF-α, interleukins and TLR4. By means of gene repression, the miRNAs here described modulate the nociceptive process as well as the autoimmune response that characterize this disease.

Uncovering a Shared Epitope-Activated Protein Citrullination Pathway

Rheumatoid arthritis (RA) is closely associated with shared epitope (SE)-coding HLA-DRB1 alleles and circulating anticitrullinated protein Abs (ACPA), but neither the respective pathogenic roles of SE and ACPA in RA nor the mechanisms underlying their coassociation are known. It was recently shown that the SE functions as a signal transduction ligand that activates a cell surface calreticulin-mediated, proarthritogenic, bone erosive pathway in an experimental model of RA. In this study, we demonstrate that stimulation of murine macrophages with LPS or DTT facilitated cell surface translocation of calreticulin, which in turn enabled increased SE-activated calcium signaling and activation of peptidylarginine deiminase with the resultant increased cellular abundance of citrullinated proteins. The i.p. administration of LPS to transgenic mice carrying a human SE-coding HLA-DRB1 allele lead to increased serum levels of TNF-α and anticitrullinated cyclic peptide Abs, along with terminal phalanx bone destruction. These data uncover a previously unknown signal transduction pathway by which the SE facilitates protein citrullination, ACPA production, and bone destruction.

Prognostic values of YTHDF1 regulated negatively by mir-3436 in Glioma

M6A methylation is likely to be closely associated with the occurrence and development of tumours. In this study, we demonstrated that the transcription levels of the m6A RNA methylation regulators are closely related to the prognosis of glioma. Univariate Cox analysis was performed on the expression levels of methylation regulators and selected three hub genes in glioma. Next, we systematically compared the expression of these m6A RNA methylation regulators in gliomas with different clinicopathological features. The overall survival (OS) curve of the hub genes was initially established based on TCGA database information. YTHDF1 was selected from the hub genes following survival and prognosis analysis. A nomogram was developed to predict the survival probability. We further performed cell function and in vivo xenograft tumour experiments to further verify its role in tumour progression. Next, based on the miRanda and miRDB databases, we predicted one microRNA, hsa-mir-346, that might regulate and bind to 3'UTR of YTHDF1, which was confirmed by our fluorescent enzyme reporter gene experiment. In summary, m6A RNA methylation regulators play a potential role in the progression of gliomas. YTHDF1 may have an essential function in glioma diagnosis, treatment and prognosis.

Epigenetics in rheumatoid arthritis; fibroblast-like synoviocytes as an emerging paradigm in the pathogenesis of the disease

Rheumatoid arthritis (RA) is characterized by immune dysfunctions and chronic inflammation that mainly affects diarthrodial joints. Genetics has long been surveyed in searching for the etiopathogenesis of the disease and partially clarified the conundrums within this context. Epigenetic alterations, such as DNA methylation, histone modifications, and noncoding RNAs, which have been considered to be involved in RA pathogenesis, likely explain the nongenetic risk factors. Epigenetic modifications may influence RA through fibroblast-like synoviocytes (FLSs). It has been shown that FLSs play an essential role in the onset and exacerbation of RA, and therefore, they may illustrate some aspects of RA pathogenesis. These cells exhibit a unique DNA methylation profile in the early stage of the disease that changes with disease progression. Histone acetylation profile in RA FLSs is disrupted through the imbalance of histone acetyltransferases and histone deacetylase activity. Furthermore, dysregulation of microRNAs (miRNAs) is immense. Most of these miRNAs have shown an aberrant expression in FLSs that are involved in proliferation and cytokine production. Besides, dysregulation of long noncoding RNAs in FLSs has been revealed and attributed to RA pathogenesis. Further investigations are needed to get a better view of epigenetic alterations and their interactions. We also discuss the role of these epigenetic alterations in RA pathogenesis and their therapeutic potential.

A comprehensive pathway map of IL-18-mediated signalling

Interleukin-18 (IL-18) is a member of the IL-1 family of cytokines and was initially described as an IFN-γ-inducing factor derived from anti-CD3-stimulated T-helper (Th)1 cells. IL-18 plays a significant role in the activation of hematopoietic cell types mediating both Th1 and Th2 responses and is the primary inducer of interferon-γ in these cells. The biological activity of IL-18 is mediated through its binding to the IL-18 receptor complex and activation of nuclear factor-κB (NF-κB), culminating in the production and release of several cytokines, chemokines, and cellular adhesion molecules. In certain cell types, IL-18 also activates mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase/ AKT serine/threonine kinase (PI3K/AKT) signaling modules leading to the production and release of proinflammatory cytokines. IL-18-mediated signaling acts as one of the vital components of the immunomodulatory cytokine networks involved in host defense, inflammation, and tissue regeneration. Albeit its biomedical importance, a comprehensive resource of IL-18 mediated signaling pathway is currently lacking. In this study, we report on the development of an integrated pathway map of IL-18/IL-18R signaling. The pathway map was developed through literature mining from published literature based on manual curation guidelines adapted from NetPath and includes information on 16 protein-protein interaction events, 38 enzyme-catalysis events, 12 protein translocation events, 26 activations/inhibition events, transcriptional regulators, 230 gene regulation events and 84 induced protein expression events. The IL-18 signaling pathway can be freely accessed through the WikiPathways database (https://www.wikipathways.org/index.php/Pathway:WP4754).

Recent findings regarding the effects of microRNAs on fibroblast-like synovial cells in rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disease with severe joint inflammation and destruction characterized by marked hyperplasia of the lining layer of the synovium. Fibroblast-like synovial cells (FLS) is a key cellular component within the synovia; it plays pivotal roles in RA pathogenesis by unfavorable behaviors such as producing inflammatory cytokines and chemokines, and hyperproliferation. MicroRNAs are evolutionarily conserved small non-coding RNAs (length is 18-25 nucleotides) that regulate gene expression at the post-transcriptional level. There is increasing interest in the involvement of microRNAs in autoimmune diseases including RA. Recent studies revealed the regulation of the function of FLS by microRNAs. Here, we review the known functional microRNAs in RA and summarize the potential uses of these small molecules in the treatment of RA.

Interactions between immune response to fungal infection and microRNAs: The pioneer tuners

Due to their physiological and biological characteristics, numerous fungi are potentially emerging pathogens. Active dynamicity of fungal pathogens causes life-threatening infections annually impose high costs to the health systems. Although immune responses play crucial roles in controlling the fate of fungal infections, immunocompromised patients are at high risk with high mortality. Tuning the immune response against fungal infections might be an effective strategy for controlling and reducing the pathological damages. MicroRNAs (miRNAs) are known as the master regulators of immune response. These single-stranded tuners (18-23 bp non-coding RNAs) are endogenously expressed by all metazoan eukaryotes and have emerged as the master gene expression controllers of at least 30% human genes. In this review article, following the review of biology and physiology (biogenesis and mechanism of actions) of miRNAs and immune response against fungal infections, the interactions between them were scrutinised. In conclusion, miRNAs might be considered as one of the potential goals in immunotherapy for fungal infections. Undoubtedly, advanced studies in this field, further identifying of miRNA roles in governing the immune response, pave the way for inclusion of miRNA-related immunotherapeutic in the treatment of life-threatening fungal infections.

MicroRNAs in rheumatoid arthritis: From pathogenesis to clinical impact

Over the last decade, many epigenetic mechanisms that contribute in the pathogenesis of autoimmune disorders have been revealed. MicroRNAs (miRNAs) are small, non-coding, RNA molecules that bind to messenger RNAs and disrupt the transcription of target genes. Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease in which a plethora of epigenetic changes take place. Current research on RA epigenetics has focused mainly on miRNAs. Genetic variance of some miRNA genes, especially miR-499, might predispose an individual to RA development. Additionally, altered expression of many miRNAs has been discovered in several cells, tissues and body fluids in patients with RA. MiRNAs expression also differs depending on disease's stage and activity. Serum miR-22 and miR-103a might predict RA development in susceptible individuals (pre-RA), while serum miR-16, miR-24, miR-125a and miR-223 levels are altered in early RA (disease duration <12 months) patients compared to established RA or healthy individuals. Moreover, serum miR-223 levels have been associated with RA activity and disease relapse. What is more, serum levels of several miRNAs, including miR-125b and miR-223, could be used to predict response to RA treatment. Finally, miRNA analogs or antagonists have been used as therapeutic regimens in experimental arthritis models and have demonstrated promising results. In conclusion, the research on the miRNA alterations in RA sheds light to several aspects of RA pathogenesis, introduces new biomarkers for RA diagnosis and treatment response prediction and offers the opportunity to discover new, targeted drugs for patients with RA.

MicroRNA and exosome: Key players in rheumatoid arthritis

Rheumatoid arthritis (RA) is known as one of important autoimmune disorders which can lead to joint pain and damage throughout body. Given that internal (ie, genetic and epigenetic alterations) and external factors (ie, lifestyle changes, age, hormones, smoking, stress, and obesity) involved in RA pathogenesis. Increasing evidence indicated that cellular and molecular alterations play critical roles in the initiation and progression of RA. Among various targets and molecular signaling pathways, microRNAs (miRNAs) and their regulatory networks have key roles in the RA pathogenesis. It has been showed that deregulation of many miRNAs involved in different stages of RA. Hence, identification of miRNAs and their signaling pathways in RA, could contribute to new knowledge which help to better treatment of patients with RA. Besides miRNAs, exosomes have been emerged as key messengers in RA pathogenesis. Exsosomes are nanocarriers which could be released from various cells and lead to changing of behaviors recipient cells via targeting their cargos (eg, proteins, messenger RNAs, miRNAs, long noncoding RNAs, DNAs). Here, we summarized several miRNAs involved in RA pathogenesis. Moreover, we highlighted the roles of exosomes in RA pathogenesis.

Circulating microRNA-23b as a new biomarker for rheumatoid arthritis

MicroRNA-23b (miR-23b) is associated with inflammation and autoimmune diseases. This study evaluated miR-23b expression and assessed its potential as a biomarker of disease activity for rheumatoid arthritis (RA). Differential expression of microRNAs was determined by miRNA microarray analysis in fibroblast-like synoviocytes (FLSs) from four trauma patients as healthy controls (HCs) and eight RA patients. The microarray results showed elevated expression of miR-23b in FLSs from RA patients and this finding was corroborated by real-time quantitative polymerase chain reaction (RT-qPCR) and in situ hybridization using synovial tissues (STs). Furthermore, we found miR-23b levels in plasma of RA patients were significantly higher than in HCs, and plasma miR-23b levels positively correlated with the erythrocyte sedimentation rate (ESR), hypersensitive C-reactive protein (hs-CRP), C-reactive protein (CRP), DAS28, and platelet (PLT) count (P < 0.05). MiR-23b levels in plasma inversely correlated with the levels of hemoglobin (Hb), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) (P < 0.05), but not with rheumatoid factor (RF) or anti-cyclic citrullinated peptide antibodies (ACPA) (P > 0.05). Moreover, patients with anorexia showed higher levels of miR-23b in plasma than those without anorexia. Similar results were observed with fatigue. Appropriate treatment for RA not only ameliorated the disease condition but also reversed the elevated plasma miR-23b level remarkably. These results suggest that circulating miR-23b may be a promising biomarker for RA disease activity.

Are innovation and new technologies in precision medicine paving a new era in patients centric care?

Healthcare is undergoing a transformation, and it is imperative to leverage new technologies to generate new data and support the advent of precision medicine (PM). Recent scientific breakthroughs and technological advancements have improved our understanding of disease pathogenesis and changed the way we diagnose and treat disease leading to more precise, predictable and powerful health care that is customized for the individual patient. Genetic, genomics, and epigenetic alterations appear to be contributing to different diseases. Deep clinical phenotyping, combined with advanced molecular phenotypic profiling, enables the construction of causal network models in which a genomic region is proposed to influence the levels of transcripts, proteins, and metabolites. Phenotypic analysis bears great importance to elucidat the pathophysiology of networks at the molecular and cellular level. Digital biomarkers (BMs) can have several applications beyond clinical trials in diagnostics-to identify patients affected by a disease or to guide treatment. Digital BMs present a big opportunity to measure clinical endpoints in a remote, objective and unbiased manner. However, the use of "omics" technologies and large sample sizes have generated massive amounts of data sets, and their analyses have become a major bottleneck requiring sophisticated computational and statistical methods. With the wealth of information for different diseases and its link to intrinsic biology, the challenge is now to turn the multi-parametric taxonomic classification of a disease into better clinical decision-making by more precisely defining a disease. As a result, the big data revolution has provided an opportunity to apply artificial intelligence (AI) and machine learning algorithms to this vast data set. The advancements in digital health opportunities have also arisen numerous questions and concerns on the future of healthcare practices in particular with what regards the reliability of AI diagnostic tools, the impact on clinical practice and vulnerability of algorithms. AI, machine learning algorithms, computational biology, and digital BMs will offer an opportunity to translate new data into actionable information thus, allowing earlier diagnosis and precise treatment options. A better understanding and cohesiveness of the different components of the knowledge network is a must to fully exploit the potential of it.

Interleukin-18 in Health and Disease

Interleukin (IL)-18 was originally discovered as a factor that enhanced IFN-γ production from anti-CD3-stimulated Th1 cells, especially in the presence of IL-12. Upon stimulation with Ag plus IL-12, naïve T cells develop into IL-18 receptor (IL-18R) expressing Th1 cells, which increase IFN-γ production in response to IL-18 stimulation. Therefore, IL-12 is a commitment factor that induces the development of Th1 cells. In contrast, IL-18 is a proinflammatory cytokine that facilitates type 1 responses. However, IL-18 without IL-12 but with IL-2, stimulates NK cells, CD4⁺ NKT cells, and established Th1 cells, to produce IL-3, IL-9, and IL-13. Furthermore, together with IL-3, IL-18 stimulates mast cells and basophils to produce IL-4, IL-13, and chemical mediators such as histamine. Therefore, IL-18 is a cytokine that stimulates various cell types and has pleiotropic functions. IL-18 is a member of the IL-1 family of cytokines. IL-18 demonstrates a unique function by binding to a specific receptor expressed on various types of cells. In this review article, we will focus on the unique features of IL-18 in health and disease in experimental animals and humans.

Regulatory effect of miR-346/DKK3 axis on tumor cell proliferation in colon cancer

AIM

To investigate the regulatory effect of the miR-346/DKK3 axis on tumor cell proliferation in colon cancer.

METHODS

The expression of miR-346 in normal colon epithelial cells and colon cancer cells as well as in colon tissues and noncancerous tissues was examined by RT-PCR. The effect of miR-346 on the proliferation of colon cancer cells was examined by MTT assay. Flow cytometry was used to detect the effect of miR-346 on the colon cancer cell cycle. The dual luciferase reporter gene assay was used to validate the binding relationship between miR-346 and DKK3. The effect of DKK3 on the function of colon cancer cells was studied by transfecting colon cancer cells with siRNA and pcDNA-DKK3.

RESULTS

The expression of miR-346 in colon cancer cells was significantly upregulated. Overexpression of miR-346 promoted the proliferation of colon cancer cells. The proportion of cells in G1 phase decreased, and the proportion of cells in S phase and G2/M phase increased. The dual luciferase reporter assay showed that miR-346 bound directly to the 3'-UTR of DKK3. Inhibition of DKK3 using siRNA promoted the proliferation of colon cancer cells, reduced the proportion of cells in G1 phase and increased the proportion of cells in S phase and G2/M phase. Further, overexpression of DKK3 partially abrogated the proliferative effect of miR-346 on colon cancer cells.

CONCLUSION

MiR-346 promotes the proliferation of colon cancer cells by inhibiting DKK3.

circFBLIM1 act as a ceRNA to promote hepatocellular cancer progression by sponging miR-346

BACKGROUD

Accumulating evidences indicate that circular RNAs (circRNAs), a class of non-coding RNAs, play important roles in tumorigenesis. However, the function of circRNAs in hepatocellular cancer (HCC) is largely unknown.

METHODS

We performed circRNA microarrays to identify circRNAs that are aberrantly expressed in HCC tissues. Expression levels of a significantly upregulated circRNA, circFBLIM1, was detected by quantitative real-time PCR (qRT-PCR) in HCC cell lines and tissues. Then, we examined the functions of circFBLIM1 in HCC by cell proliferation, apoptosis, invasion and mouse xenograft assay. In addition, luciferase assay and RNA immunoprecipitation (RIP) assay were used to explore the miRNA sponge function of circFBLIM1 in HCC.

RESULTS

Microarray analysis and qRT-PCR verified a circRNA termed circFBLIM1 that was upregulated in HCC tissues and cell lines. Knockdown of circFBLIM1 inhibited proliferation, invasion and promoted apoptosis in HCC. Via luciferase reporter assays, circFBLIM1 and FBLIM1 were observed to directly bind to miR-346. Subsequent experiments showed that circFBLIM1 and FBLIM1 regulated the expression of each other by sponging miR-346.

CONCLUSIONS

Taken together, we conclude that circFBLIM1 may function as a competing endogenous RNA (ceRNA) to regulate FBLIM1 expression through sponging miR-346 to exert regulatory functions in HCC. circFBLIM1 may be a diagnostic biomarker and potential target for HCC therapy.

Synovial Predictors of Differentiation to Definite Arthritis in Patients With Seronegative Undifferentiated Peripheral Inflammatory Arthritis: microRNA Signature, Histological, and Ultrasound Features

Objectives: To examine synovial tissue (ST) predictors of clinical differentiation in patients with seronegative undifferentiated peripheral inflammatory arthritis (UPIA).

Methods: Fourty-two patients with IgA/IgM-Rheumatoid Factor and anti-citrullinated peptide antibodies negative UPIA, naive to Disease-Modifying Anti-Rheumatic Drugs, underwent Gray Scale (GSUS) and power Doppler (PDUS) evaluation and Ultrasound (US) guided ST biopsy. CD68, CD3, CD21, CD20, and CD31 synovial expression was evaluated by immunohistochemistry. Whole ST microRNA expression was assessed using miScript miRNA PCR Array. Peripheral blood (PB) and synovial fluid (SF) IL-6, VEGF-A, and VEGF-D levels were measured by ELISA and ST TNF expression was assessed by RT-PCR. Each patient was prospectively monitored and classified at baseline and within 1 year as UPIA, Rheumatoid Arthritis (RA), Spondyloarthritis (SpA) or Psoriatic Arthritis (PsA), respectively.

Results: At baseline, CD68⁺ cells were the most common cells within the lining layer (p < 0.001) in seronegative UPIA, directly correlating with GSUS (R = 0.36; p = 0.02) and PDUS (R = 0.55; p < 0.001). Synovial CD31⁺ vessels count directly correlated with GSUS (R = 0.41; p = 0.01) and PDUS (R = 0.52; p < 0.001). During the follow-up, 6 (14.3%) UPIA reached a definite diagnosis (2 RA, 2 SpA and 2 PsA, respectively). At baseline, UPIA who differentiated had higher GSUS (p = 0.01), PDUS scores (p = 0.02) and higher histological scores for CD68⁺ (p = 0.005 and p = 0.04 for lining and sublining respectively), sublining CD3⁺ cells (p = 0.002), CD31⁺ vessels count (p < 0.001) and higher IL-6 PB levels (p = 0.01) than patients who remained as UPIA. MiRNA PCR Array showed that among the 86 tested miRNA species, at baseline, miR-346 and miR-214 were significantly down-regulated (p = 0.02 for both) in ST of UPIA who differentiated than in patients who remained as UPIA, inversely correlating with the lining CD68⁺ cells IHC score (R = −0.641; p = 0.048) and CD31⁺ vessels count (R = −0.665; p = 0.036) and with higher baseline ST expression of TNF (p = 0.014). Finally, logistic regression analysis demonstrated that baseline GSUS and PDUS scores ≥1.5 [OR:22.93 (95%CI:0.98–534.30)] and CD31⁺ vessels count ≥24.3 [OR:23.66 (95%CI:1.50–373.02)] were independent factors associated with the development of definite arthritis.

Conclusions: MiRNA signature, histological and US features of ST may help in the identification of seronegative UPIA with high likelihood of clinical differentiation toward definite seronegative arthritis.

IRE1α Implications in Endoplasmic Reticulum Stress-Mediated Development and Pathogenesis of Autoimmune Diseases

Inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) is the most prominent and evolutionarily conserved endoplasmic reticulum (ER) membrane protein. This transduces the signal of misfolded protein accumulation in the ER, named as ER stress, to the nucleus as “unfolded protein response (UPR).” The ER stress-mediated IRE1α signaling pathway arbitrates the yin and yang of cell life. IRE1α has been implicated in several physiological as well as pathological conditions, including immune disorders. Autoimmune diseases are caused by abnormal immune responses that develop due to genetic mutations and several environmental factors, including infections and chemicals. These factors dysregulate the cell immune reactions, such as cytokine secretion, antigen presentation, and autoantigen generation. However, the mechanisms involved, in which these factors induce the onset of autoimmune diseases, are remaining unknown. Considering that these environmental factors also induce the UPR, which is expected to have significant role in secretory cells and immune cells. The role of the major UPR molecule, IRE1α, in causing immune responses is well identified, but its role in inducing autoimmunity and the pathogenesis of autoimmune diseases has not been clearly elucidated. Hence, a better understanding of the role of IRE1α and its regulatory mechanisms in causing autoimmune diseases could help to identify and develop the appropriate therapeutic strategies. In this review, we mainly center the discussion on the molecular mechanisms of IRE1α in the pathophysiology of autoimmune diseases.

Dysregulation of microRNAs in autoimmune diseases: Pathogenesis, biomarkers and potential therapeutic targets

MicroRNAs (miRNAs) are small, single-stranded, endogenous non-coding RNAs that repress the expression of target genes via post-transcriptional mechanisms. Due to their broad regulatory effects, the precisely regulated, spatial-specific and temporal-specific expression of miRNAs is fundamentally important to various biological processes including the immune homeostasis and normal function of both innate and adaptive immune response. Aberrance of miRNAs is implicated in the development of various human diseases, especially cancers. Increasing evidence has revealed a dysregulated expression pattern of miRNAs in autoimmune diseases, among which many play key roles in the pathogenesis. In this review we summarize these findings on miRNA dysregulation implicated in autoimmune diseases, focusing on four representative systemic autoimmune diseases, i.e. systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis and dermatomyositis. The causes of the dysregulation of miRNA expression in autoimmune diseases may include genetic and epigenetic variants, and various environmental factors. Further understanding of miRNA dysregulation and its mechanisms during the development of different autoimmune diseases holds enormous potential to bring about novel therapeutic targets or strategies for these complex human disorders, as well as novel circulating or exosomal miRNA biomarkers.

MicroRNA-146a suppresses rheumatoid arthritis fibroblast-like synoviocytes proliferation and inflammatory responses by inhibiting the TLR4/NF-kB signaling

This study investigated whether microRNA-146a (miR-146a) mediating TLR4/NF-κB pathway affected proliferation and inflammatory responses of rheumatoid arthritis fibroblast-like synoviocytes from 12 RA patients (RA-FLSs). FLSs in the logarithmic growth phase were assigned into the control, miR-146a mimic miR-146a inhibitor, Tak-242 (treated with TLR4/NF-κB pathway inhibitor) and mimic + lipopolysaccharide (LPS) groups. Cell proliferation and apoptosis were detected using CCK-8 assay and flow cytometry. The expression of miR-146a, TLR4/NF-κB pathway-related proteins and cytokines were determined by RT-qPCR, western blotting and ELISA, and the release of NO by Greiss reaction. RA rat models were constructed and the primary cells were classified into the control, negative control (NC), miR-146a mimic, miR-146a inhibitor, Tak-242, mimic + LPS, and TLR4 groups. Immunohistochemistry was used to detect the expression of proliferating cell nuclear antigen (PCNA) and intercellular adhesion molecular-1 (ICAM-1). The results showed that miR-146a levels were lower in RA-FLSs than control fibroblasts. miR-146a mimic and Tak-242 decreased RA-FLS proliferation and increased RA-FLS apoptosis, while miR-146a inhibitor had an opposite trend. miR-146a mimic and Tak-242 also decreased expression of TLR4, NF-κB, IL-1β, IL-6, IL-8, IL-17, COX-2, MMP-3, Seprase, and iNOS, as well as reduced NO level in RA-FLSs while miR-146a inhibitor and TLR4 increased them. TLR4 and NF-κB levels and the positive rates of PCNA and ICAM-1 expressions were lower in RA-FLSs from RA rats given miR-146a mimic from control or miR-146a inhibitor-treated rats. These results suggest that miR-146a inhibits the proliferation and inflammatory response of RA-FLSs by down-regulating TLR4/NF-κB pathway.

Role of extracellular vesicles in rheumatoid arthritis

Cell-derived extracellular vesicles (EVs) are involved in the pathogenesis of rheumatoid arthritis (RA), playing important roles in antigen presentation, inflammation, angiogenesis, cell-cell signal communication, thrombosis, and articular cartilage extracellular matrix degradation. Understanding the pathogenic mechanism of RA is important for developing therapies. The pathogenic indicators of RA, such as submicron-sized EVs, represent promising biomarkers for evaluating RA activity. This review summarizes the recent advances in understanding the pathogenesis of RA, and sheds light on the pathogenic as well as anti-inflammatory or immunosuppressive roles of EVs. We suggest that EVs could be harnessed as tools for drug delivery or targets for RA therapies.

Altered Expression of MicroRNAs in Rheumatoid Arthritis

Rheumatoid arthritis is one of the most common types of inflammatory joint diseases. Women, smokers, and people with positive family history are more susceptible to this disease. Diagnostic criteria include at least one swollen joint that has not been caused by other diseases. MicroRNAs are non-coding RNAs that are evolutionarily conserved and have a length of 18-25 nucleotides. MicroRNAs control gene expression at the post-transcriptional level via promoting mRNA degradation or translational repression. Recognition of alterations in microRNA status and their respective targets, may offer an opportunity to better identify the pathways that are involved in the etiopathogenesis of autoimmune diseases. It has been suggested that microRNAs may serve as potential biomarkers for both diagnosis and prognosis of autoimmune diseases. Here, we review the available evidence on the deregulations of microRNA expression in rheumatoid arthritis. More precisely, this review focuses on the microRNA involved in T cell regulation and gives perspectives on the use of this microRNA as biomarkers of diagnosis, prognosis, or intervention efficacy. J. Cell. Biochem. 119: 478-487, 2018. © 2017 Wiley Periodicals, Inc.

Reduced DICER1 Expression Bestows Rheumatoid Arthritis Synoviocytes Proinflammatory Properties and Resistance to Apoptotic Stimuli

OBJECTIVE

While the regulatory role of individual microRNAs (miRNAs) in rheumatoid arthritis (RA) is well established, the role of DICER1 in the pathogenesis of the disease has not yet been investigated. The purpose of this study was to analyze the expression of factors involved in miRNA biogenesis in fibroblast-like synoviocytes (FLS) from RA patients and to monitor the arthritis triggered by K/BxN serum transfer in mice deficient in the Dicer gene (Dicer(d/d) ).

METHODS

The expression of genes and precursor miRNAs was quantified by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). MicroRNA macroarray profiling was monitored by qRT-PCR. Cytokines were quantified by enzyme-linked immunosorbent assay. Experimental arthritis in mice was achieved by the transfer of serum from K/BxN donors. Apoptosis was quantified using an enzyme-linked immunosorbent assay.

RESULTS

We found decreased DICER1 and mature miRNA expression in synovial fibroblasts from RA patients. These cells were hyperresponsive to lipopolysaccharide, as evidenced by their increased interleukin-6 secretion upon stimulation. Experimental serum-transfer arthritis in Dicer(d/d) mice confirmed that an unbalanced biogenesis of miRNAs correlated with an enhanced inflammatory response. Synoviocytes from both RA patients and Dicer(d/d) mice exhibited increased resistance to apoptotic stimuli.

CONCLUSION

The findings of this study further substantiate the important role of DICER1 in the maintenance of homeostasis and the regulation of inflammatory responses.

YKL-40-Induced Inhibition of miR-590-3p Promotes Interleukin-18 Expression and Angiogenesis of Endothelial Progenitor Cells

YKL-40, also known as human cartilage glycoprotein-39 or chitinase-3-like-1, is a pro-inflammatory protein that is highly expressed in rheumatoid arthritis (RA) patients. Angiogenesis is a critical step in the pathogenesis of RA, promoting the infiltration of inflammatory cells into joints and providing oxygen and nutrients to RA pannus. In this study, we examined the effects of YKL-40 in the production of the pro-inflammatory cytokine interleukin-18 (IL-18), and the stimulation of angiogenesis and accumulation of osteoblasts. We observed that YKL-40 induces IL-18 production in osteoblasts and thereby stimulates angiogenesis of endothelial progenitor cells (EPCs). We found that this process occurs through the suppression of miR-590-3p via the focal adhesion kinase (FAK)/PI3K/Akt signaling pathway. YKL-40 inhibition reduced angiogenesis in in vivo models of angiogenesis: the chick embryo chorioallantoic membrane (CAM) and Matrigel plug models. We report that YKL-40 stimulates IL-18 expression in osteoblasts and facilitates EPC angiogenesis.

Epigenetic alterations in rheumatoid arthritis fibroblast-like synoviocytes

Rheumatoid arthritis is an immune-mediated disease that primarily affects diarthrodial joints. Susceptibility and severity of this disease are influenced by nongenetic factors, such as environmental stress, suggesting an important role of epigenetic changes. In this review, we summarize the epigenetic changes (DNA methylation, histone modification and miRNA expression) in fibroblast-like synoviocytes, which are the joint-lining mesenchymal cells that play an important role in joint inflammation and damage. We also review the effects of these epigenetic changes on rheumatoid arthritis pathogenesis and discuss their therapeutic potential.

Non-Lethal Endotoxin Injection: A Rat Model of Hypercoagulability

Systemic inflammation co-activates coagulation, which unchecked culminates in a lethal syndrome of multi-organ microvascular thrombosis known as disseminated intravascular coagulation (DIC). We studied an endotoxin-induced inflammatory state in rats to identify biomarkers of hemostatic imbalance favoring hypercoagulability. Intraperitoneal injection of LPS at 15 mg/kg body weight resulted in peripheral leukopenia and widespread neutrophilic sequestration characteristic of an acute systemic inflammatory response. Early indicators of hemostatic pathway activation developed within 4 hours, including increased circulating concentrations of procoagulant extracellular vesicles (EVs), EVs expressing endothelial cell and platelet membrane markers, and high concentration of soluble intercellular adhesion molecule-1 (sICAM-1), plasminogen activator inhibitor-1 (PAI-1), and D-dimers. Inflammation persisted throughout the 48-hour observation period; however, increases were found in a subset of serum microRNA (miRNA) that coincided with gradual resolution of hemostatic protein abnormalities and reduction in EV counts. Dose-adjusted LPS treatment in rats provides a time-course model to develop biomarker profiles reflecting procoagulant imbalance and rebalance under inflammatory conditions.

The Impact of MicroRNA-223-3p on IL-17 Receptor D Expression in Synovial Cells

OBJECTIVE

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease affecting joints. Elevated plasma levels of microRNA-223-3p (miR-223-3p) in patients with RA are implicated in the pathogenesis of the disease. This study aimed to analyze the functional role of miR-223-3p in the pathogenesis of RA by overexpressing miR-223-3p in synovial cell lines.

METHODS

Arthritis was induced in the RA model of SKG mice by injection of ß-glucan. The histopathologic features of joints were examined using hematoxylin and eosin and immunohistochemical staining. Plasma levels of miRNA were determined by panel real-time PCR analysis. Target genes of the differentially expressed miRNAs in SKG mice were analyzed using miRNA target prediction algorithms. The dual-luciferase reporter system was used to evaluate the relationship between miR-223-3p and IL-17 receptor D (IL-17RD). The activity of miR-223-3p was analyzed by transfection of plasmid vectors overexpressing miR-223-3p into IL-17RD-expressing NIH3T3 and MH7A cell lines. Il6 and Il17rd mRNA expression was analyzed by quantitative real-time PCR. IL-17RD protein expression was analyzed by western blot analysis.

RESULTS

We identified 17 upregulated miRNAs (fold change > 2.0) in plasma of SKG mice injected with ß-glucan relative to untreated SKG mice. Il17rd was identified as the candidate target gene of miR-223-3p using five miRNA target prediction algorithms. The transfection of plasmid vectors overexpressing miR-223-3p into NIH3T3 and MH7A cells resulted in the downregulation of Il17rd expression and upregulation of Il6 expression. Expression of miR-223-3p and Il6 mRNA in MH7A cells was upregulated; however, that of Il17rd mRNA was downregulated following TNF-α stimulation. IL-17RD expression in synovial tissues from SKG mice and RA patients was inversely correlated with the severity of arthritis.

CONCLUSION

This study is the first to demonstrate that miR-223-3p downregulates IL-17RD in both mouse and human cells; miR-223-3p may contribute to the pathogenesis of RA by downregulating the expression of IL-17RD and upregulating that of IL-6 in synovial cells.

MiR-346 promotes the biological function of breast cancer cells by targeting SRCIN1 and reduces chemosensitivity to docetaxel

MicroRNAs (miRNAs) are a class of highly conserved small noncoding RNAs that play pivotal roles at the post-transcriptional level in the biological function of various cancers, including breast cancer. In our study, miR-346 mimic, inhibitor, negative control or si-SRCIN1 were transfected into MCF-7 and MCF-7/Doc cells, respectively. Quantitative real time PCR (qRT-PCR) was used to measure miR-346 and SRCIN1 mRNA expressions and western blot was used to detect the expression of SRCIN1 in protein level. CCK-8 and colony formation were employed to verify cell viability and proliferation. Flow cytometry showed the apoptosis. Transwell was performed to detect migration and invasion. The luciferase reporter assay data showed the target correlation of miR-346 and SRCIN1. Firstly, we found that the expression of miR-346 was higher in breast cancer tissues than in their paired corresponding non-cancerous tissues and there was significant inversed correlation between miR-346 and SRCIN1. Overexpression of miR-346 promoted cell proliferation, colony formation, migration and invasion, and reduced apoptosis, sensitivity to Docetaxel (Doc). SRCIN1 was identified as a direct target of miR-346, whose silencing promoted cell proliferation and the IC50 of Doc. Moreover, SRCIN1 silencing reduced the effect of miR-346 down-expression. Taken together, miR-346 may function as an oncogenic miRNA and mediate chemosensitivity to docetaxel through targeting SRCIN1 in breast cancer, targeted modulation of miR-346 expression may became a potential strategy for the treatment.

A novel infection- and inflammation-associated molecular signature in peripheral blood of myasthenia gravis patients

Myasthenia gravis (MG) is a T-cell dependent autoimmune disorder of the neuromuscular junction, characterised by muscle weakness and fatigability. Autoimmunity is thought to initiate in the thymus of acetylcholine receptor (AChR)-positive MG patients; however, the molecular mechanisms linking intra-thymic MG pathogenesis with autoreactivity via the circulation to the muscle target organ are poorly understood. Using whole-transcriptome sequencing, we compared the transcriptional profile of peripheral blood mononuclear cells from AChR-early onset MG (AChR-EOMG) patients with healthy controls: 178 coding transcripts and 229 long non-coding RNAs, including 11 pre-miRNAs, were differentially expressed. Among the 178 coding transcripts, 128 were annotated of which 17% were associated with the 'infectious disease' functional category and 46% with 'inflammatory disease' and 'inflammatory response-associated' categories. Validation of selected transcripts by qPCR indicated that of the infectious disease-related transcripts, ETF1, NFKB2, PLK3, and PPP1R15A were upregulated, whereas CLC and IL4 were downregulated in AChR-EOMG patients; in the 'inflammatory' categories, ABCA1, FUS, and RELB were upregulated, suggesting a contribution of these molecules to immunological dysfunctions in MG. Data selection and validation were also based on predicted microRNA-mRNA interactions. We found that miR-612, miR-3654, and miR-3651 were increased, whereas miR-612-putative AKAp12 and HRH4 targets and the miR-3651-putative CRISP3 target were downregulated in AChR-EOMG, also suggesting altered immunoregulation. Our findings reveal a novel peripheral molecular signature in AChR-EOMG, reflecting a critical involvement of inflammatory- and infectious disease-related immune responses in disease pathogenesis.

miRNA-Regulated Key Components of Cytokine Signaling Pathways and Inflammation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an inflammatory disease that primarily affects joints. This autoimmune disease pathogenesis is related to cytokine signaling. In this review, we have described the existence of various microRNAs (miRNAs) involved in regulation of major protein cascades of cytokine signaling associated with RA. Moreover, we have tried to portray the role of various miRNAs in different cytokines such as TNF-α, IL-1, IL-6, IL-10, IL-17, IL-18, IL-21, and granulocyte macrophage colony-stimulating factor (GMCSF). Along with this, we have also discussed the miRNA regulation in T cells and synovial tissue. From the analyzed data, we suggest that miR-146a and miR-155 might be the potential therapeutic target for treating RA. The insight illustrated in this review will offer a better understanding of the role of miRNA in cytokine signaling pathways and inflammation during RA and could project them as diagnostic or therapeutic agents in near future.

Pattern recognition receptor mediated downregulation of microRNA-650 fine-tunes MxA expression in dendritic cells infected with influenza A virus

MicroRNAs are important posttranscriptional regulators of gene expression, which have been shown to fine-tune innate immune responses downstream of pattern recognition receptor (PRR) signaling. This study identifies miR-650 as a novel PRR-responsive microRNA that is downregulated upon stimulation of primary human monocyte-derived dendritic cells (MDDCs) with a variety of different microbe-associated molecular patterns. A comprehensive target search combining in silico analysis, transcriptional profiling, and reporter assays reveals that miR-650 regulates several well-known interferon-stimulated genes, including IFIT2 and MXA. In particular, downregulation of miR-650 in influenza A infected MDDCs enhances the expression of MxA and may therefore contribute to the establishment of an antiviral state. Together these findings reveal a novel link between miR-650 and the innate immune response in human MDDCs.

MicroRNA-346 functions as an oncogene in cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is an epidermal keratinocyte-derived skin tumor, which is the second most common skin cancer in the general population. Recently, studies showed that microRNAs (miRNAs) played an important role in the development of cancer. In our study, we showed that the expression of SRCIN1 was lower in cSCC tissues than in the matched normal tissues. Moreover, there was significant inversed correlation between miR-346 and SRCIN1 in cSCC tissues. The luciferase reporter assay data showed that miR-346 can target the SRCIN1 message via the 3'-untranslated region (UTR) of SRCIN1. Overexpression of miR-346 inhibited the messenger RNA (mRNA) and protein expression of SRCIN1 in the A431 cells. In addition, ectopic expression of miR-346 promoted the A431 cell proliferation and migration. Meanwhile, SRCIN1 overexpression inhibited the A431 cell proliferation and migration. Rescue experiment has showed that SRCIN1 overexpression reduced the miR-346-induced A431 cell proliferation and migration. Herein, this study may provide miR-346 as a new therapeutic target for cSCC.

MicroRNAs: Emerging Regulators of Immune-Mediated Diseases

MicroRNAs (miRNAs) represent the most abundant class of regulators of gene expression in humans: they regulate one-third of human protein-coding genes. These small noncoding ∼22-nucleotides (nt)-long RNAs originate by multistep process from miRNA genes localized in the genomic DNA. To date, more than 1420 miRNAs have been identified in humans (miRBase v17). The main mechanism of miRNA action is the posttranscriptional regulation via RNA interference with their target mRNAs. The majority of target mRNAs (more than 80%) undergo degradation after recognition by complementary miRNA; the translational inhibition with little or no influence on mRNA levels has been also reported. Each miRNA may suppress multiple mRNA targets (average ∼200), and at the same time, one mRNA can be targeted by many miRNAs enabling to control a spectrum wide range of cellular processes. Recently, the role of miRNAs in the development of immune cells and the maintenance of immune system homeostasis gained attention, and the involvement of miRNAs in the pathogenesis of several immune system diseases has emerged. This review focuses on the role of miRNAs in autoimmune disorders (systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease and psoriasis), inflammatory pathologies of distinct organ (atherosclerosis, osteoarthritis and atopic eczema) and/or systemic locations such as allergy. The role of miRNAs, their predicted and known mRNA targets and description of their actions in physiological immune reactions and in the pathological processes ongoing in immune-mediated human disorders will be discussed. Finally, miRNA-based diagnostics and therapeutic potentials will be highlighted.