Hsa_circ_0060450 Negatively Regulates Type I Interferon-Induced Inflammation by Serving as miR-199a-5p Sponge in Type 1 Diabetes Mellitus

MicroRNA signatures in the pathogenesis and therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a persistent inflammatory illness of the gastrointestinal tract (GIT) triggered by an inappropriate immune response to environmental stimuli in genetically predisposed persons. Unfortunately, IBD patients' quality of life is negatively impacted by the symptoms associated with the disease. The exact etiology of IBD pathogenesis is not fully understood, but the emerging research indicated that the microRNA (miRNA) plays an important role. miRNAs have been documented to possess a significant role in regulating pro- and anti-inflammatory pathways, in addition to their roles in several physiological processes, including cell growth, proliferation, and apoptosis. Variations in the miRNA profiles might be a helpful prognostic indicator and a valuable tool in the differential diagnosis of IBD. Most interestingly, these miRNAs have a promising therapeutic target in several pre-clinical animal studies and phase 2 clinical studies to alleviate inflammation and improve patient's quality of life. This comprehensive review discusses the current knowledge about the significant physiological role of different miRNAs in the health of the intestinal immune system and addresses the role of the most relevant differentially expressed miRNAs in IBD, identify their potential targets, and emphasize their diagnostic and therapeutic potential for future research.

Circular RNAs in human diseases

Circular RNAs (circRNAs) are a unique class of RNA molecules formed through back-splicing rather than linear splicing. As an emerging field in molecular biology, circRNAs have garnered significant attention due to their distinct structure and potential functional implications. A comprehensive understanding of circRNAs' functions and potential clinical applications remains elusive despite accumulating evidence of their involvement in disease pathogenesis. Recent research highlights their significant roles in various human diseases, but comprehensive reviews on their functions and applications remain scarce. This review provides an in-depth examination of circRNAs, focusing first on their involvement in non-neoplastic diseases such as respiratory, endocrine, metabolic, musculoskeletal, cardiovascular, and renal disorders. We then explore their roles in tumors, with particular emphasis on exosomal circular RNAs, which are crucial for cancer initiation, progression, and resistance to treatment. By detailing their biogenesis, functions, and impact on disease mechanisms, this review underscores the potential of circRNAs as diagnostic biomarkers and therapeutic targets. The review not only enhances our understanding of circRNAs' roles in specific diseases and tumor types but also highlights their potential as novel diagnostic and therapeutic tools, thereby paving the way for future clinical investigations and potential therapeutic interventions.

Identifying miRNA Signatures Associated with Pancreatic Islet Dysfunction in a FOXA2-Deficient iPSC Model

The pathogenesis of diabetes involves complex changes in the expression profiles of mRNA and non-coding RNAs within pancreatic islet cells. Recent progress in induced pluripotent stem cell (iPSC) technology have allowed the modeling of diabetes-associated genes. Our recent study using FOXA2-deficient human iPSC models has highlighted an essential role for FOXA2 in the development of human pancreas. Here, we aimed to provide further insights on the role of microRNAs (miRNAs) by studying the miRNA-mRNA regulatory networks in iPSC-derived islets lacking the FOXA2 gene. Consistent with our previous findings, the absence of FOXA2 significantly downregulated the expression of islet hormones, INS, and GCG, alongside other key developmental genes in pancreatic islets. Concordantly, RNA-Seq analysis showed significant downregulation of genes related to pancreatic development and upregulation of genes associated with nervous system development and lipid metabolic pathways. Furthermore, the absence of FOXA2 in iPSC-derived pancreatic islets resulted in significant alterations in miRNA expression, with 61 miRNAs upregulated and 99 downregulated. The upregulated miRNAs targeted crucial genes involved in diabetes and pancreatic islet cell development. In contrary, the absence of FOXA2 in islets showed a network of downregulated miRNAs targeting genes related to nervous system development and lipid metabolism. These findings highlight the impact of FOXA2 absence on pancreatic islet development and suggesting intricate miRNA-mRNA regulatory networks affecting pancreatic islet cell development.

Hsa_circRNA_405498 and hsa_circRNA_100033 Serve as Potential Biomarkers for Differential Diagnosis of Type 1 Diabetes

CONTEXT

The role of circular RNAs (circRNAs) in type 1 diabetes (T1D) is largely unknown.

OBJECTIVE

We aimed to identify some circRNAs as differential diagnostic biomarkers for T1D to distinguish between patients with latent autoimmune diabetes in adults (LADA) and type 2 diabetes (T2D).

METHODS

The circRNA expression profiles were determined by Arraystar human circRNA microarray in T1D compared to controls (n = 6 each). The differentially expressed circRNAs were validated by real-time quantitative polymerase chain reaction using a validation cohort with 20 T1D and 20 controls. The diagnostic performances of the candidate circRNAs and the clinical parameters were assessed using the logistic least absolute shrinkage and selection operator (LASSO) regression model in a larger cohort with 457 individuals, including patients with T1D, T2D, and LADA, and controls.

RESULTS

We identified 110 differentially expressed circular transcripts (53 upregulated and 57 downregulated) in T1D patients compared with controls. Further analysis showed that the levels of hsa_circRNA_405498 and hsa_circRNA_100033 were significantly downregulated in T1D compared to controls (both P < .05). Moreover, the expression levels of these 2 circRNAs showed sequential downregulation from controls, patients with T2D, LADA, to T1D (P < .05). The area under the curve (AUC) of receiver operating characteristic plots in logistic LASSO regression model showed high diagnostic accuracy for combination model with the 2 circRNAs and some clinical parameters in distinguishing T1D from LADA (AUC = 0.915), T2D (AUC = 0.993), and controls (AUC = 0.992).

CONCLUSION

Our study demonstrated that hsa_circRNA_405498 and hsa_circRNA_100033 are promising novel differential diagnostic biomarkers for T1D.

Identification of HDAC9 and ARRDC4 as potential biomarkers and targets for treatment of type 2 diabetes

We aimed to identify the key potential insulin resistance (IR)-related genes and investigate their correlation with immune cell infiltration in type 2 diabetes (T2D). The GSE78721 dataset (68 diabetic patients and 62 controls) was downloaded from the Gene Expression Omnibus database and utilized for single-sample gene set enrichment analysis. IR-related genes were obtained from the Comparative Toxicology Genetics Database, and the final IR-differentially expressed genes (DEGs) were screened by intersecting with the DEGs obtained from the GSE78721 datasets. Functional enrichment analysis was performed, and the networks of the target gene with microRNA, transcription factor, and drug were constructed. Hub genes were identified based on a protein-protein interaction network. Least absolute shrinkage and selection operator regression and Random Forest and Boruta analysis were combined to screen diagnostic biomarkers in T2D, which were validated using the GSE76894 (19 diabetic patients and 84 controls) and GSE9006 (12 diabetic patients and 24 controls) datasets. Quantitative real-time polymerase chain reaction was performed to validate the biomarker expression in IR mice and control mice. In addition, infiltration of immune cells in T2D and their correlation with the identified markers were computed using CIBERSORT. We identified differential immune gene set regulatory T-cells in the GSE78721 dataset, and T2D samples were assigned into three clusters based on immune infiltration. A total of 2094 IR-DEGs were primarily enriched in response to endoplasmic reticulum stress. Importantly, HDAC9 and ARRDC4 were identified as markers of T2D and associated with different levels of immune cell infiltration. HDAC9 mRNA level were higher in the IR mice than in control mice, while ARRDC4 showed the opposite trend. In summary, we discovered potential vital biomarkers that contribute to immune cell infiltration associated with IR, which offers a new sight of immunotherapy for T2D.

Non-coding RNAs in diabetic foot ulcer- a focus on infected wounds

Diabetes mellitus is associated with a wide range of neuropathies, vasculopathies, and immunopathies, resulting in many complications. More than 30% of diabetic patients risk developing diabetic foot ulcers (DFUs). Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), play essential roles in various biological functions in the hyperglycaemic environment that determines the development of DFU. Ulceration results in tissue breakdown and skin barrier scavenging, thereby facilitating bacterial infection and biofilm formation. Many bacteria contribute to diabetic foot infection (DFI), including Staphylococcus aureus (S. aureus) et al. A heterogeneous group of "ncRNAs," termed small RNAs (sRNAs), powerfully regulates biofilm formation and DFI healing. Multidisciplinary foot care interventions have been identified for nonhealing ulcers. With an appreciation of the link between disease processes and ncRNAs, a novel therapeutic model of bioactive materials loaded with ncRNAs has been developed to prevent and manage diabetic foot complications.

The cGAS-STING pathway: a therapeutic target in diabetes and its complications

Diabetic wound healing (DWH) represents a major complication of diabetes where inflammation is a key impediment to proper healing. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway has emerged as a central mediator of inflammatory responses to cell stress and damage. However, the contribution of cGAS-STING activation to impaired healing in DWH remains understudied. In this review, we examine the evidence that cGAS-STING-driven inflammation is a critical factor underlying defective DWH. We summarize studies revealing upregulation of the cGAS-STING pathway in diabetic wounds and discuss how this exacerbates inflammation and senescence and disrupts cellular metabolism to block healing. Partial pharmaceutical inhibition of cGAS-STING has shown promise in damping inflammation and improving DWH in preclinical models. We highlight key knowledge gaps regarding cGAS-STING in DWH, including its relationships with endoplasmic reticulum stress and metal-ion signaling. Elucidating these mechanisms may unveil new therapeutic targets within the cGAS-STING pathway to improve healing outcomes in DWH. This review synthesizes current understanding of how cGAS-STING activation contributes to DWH pathology and proposes future research directions to exploit modulation of this pathway for therapeutic benefit.

Diabetes Mellitus to Accelerated Atherosclerosis: Shared Cellular and Molecular Mechanisms in Glucose and Lipid Metabolism

Diabetes is one of the critical independent risk factors for the progression of cardiovascular disease, and the underlying mechanism regarding this association remains poorly understood. Hence, it is urgent to decipher the fundamental pathophysiology and consequently provide new insights into the identification of innovative therapeutic targets for diabetic atherosclerosis. It is now appreciated that different cell types are heavily involved in the progress of diabetic atherosclerosis, including endothelial cells, macrophages, vascular smooth muscle cells, dependence on altered metabolic pathways, intracellular lipids, and high glucose. Additionally, extensive studies have elucidated that diabetes accelerates the odds of atherosclerosis with the explanation that these two chronic disorders share some common mechanisms, such as endothelial dysfunction and inflammation. In this review, we initially summarize the current research and proposed mechanisms and then highlight the role of these three cell types in diabetes-accelerated atherosclerosis and finally establish the mechanism pinpointing the relationship between diabetes and atherosclerosis.

The crucial regulatory role of type I interferon in inflammatory diseases

Type I interferon (IFN-I) plays crucial roles in the regulation of inflammation and it is associated with various inflammatory diseases including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and periodontitis, impacting people's health and quality of life. It is well-established that IFN-Is affect immune responses and inflammatory factors by regulating some signaling. However, currently, there is no comprehensive overview of the crucial regulatory role of IFN-I in distinctive pathways as well as associated inflammatory diseases. This review aims to provide a narrative of the involvement of IFN-I in different signaling pathways, mainly mediating the related key factors with specific targets in the pathways and signaling cascades to influence the progression of inflammatory diseases. As such, we suggested that IFN-Is induce inflammatory regulation through the stimulation of certain factors in signaling pathways, which displays possible efficient treatment methods and provides a reference for the precise control of inflammatory diseases.

miR-199a-5p inhibits aortic valve calcification by targeting ATF6 and GRP78 in valve interstitial cells

Calcific aortic valve disease (CAVD) is an important cause of disease burden among aging populations. Excessive active endoplasmic reticulum stress (ERS) was demonstrated to promote CAVD. The expression level of miR-199a-5p in patients with CAVD was reported to be downregulated. In this article, we aimed to investigate the function and mechanism of miR-199a-5p in CAVD. The expression level of miR-199a-5p and ERS markers was identified in calcific aortic valve samples and osteogenic induction by real-time quantitative polymerase chain reaction (RT-qPCR), immunohistochemistry, and western blotting (WB). Alizarin red staining, RT-qPCR, and WB were used for the verification of the function of miR-199a-5p. The dual luciferase reporter assay and rescue experiment were conducted to illuminate the mechanism of miR-199a-5p. In our study, the expression level of miR-199a-5p was significantly decreased in calcified aortic valves and valve interstitial cells' (VICs) osteogenic induction model, accompanying with the upregulation of ERS markers. Overexpression of miR-199a-5p suppressed the osteogenic differentiation of VICs, while downregulation of miR-199a-5p promoted this function. 78 kDa glucose-regulated protein (GRP78) and activating transcription factor 6 (ATF6), both of which were pivotal modulators in ERS, were potential targets of miR-199a-5p. miR-199a-5p directly targeted GRP78 and ATF6 to modulate osteoblastic differentiation of VICs. miR-199a-5p inhibits osteogenic differentiation of VICs by regulating ERS via targeting GRP78 and ATF6.

RNF20/RNF40 ameliorates streptozotocin-induced type 1 diabetes by activating vitamin D receptors in vivo

BACKGROUND

Type 1 diabetes is one of the chronic autoimmune diseases. Its features include the immune-triggered pancreatic beta-cells destruction. Ubiquitin ligases RNF20 and RNF40 have been discovered to participate into beta cells gene expression, insulin secretion, and expression of vitamin D receptors (VDRs). However, no reports about the role of RNF20/RNF40 in type 1 diabetes are known till now. The aim of this study was to clarify the role of RNF20/RNF40 in type 1 diabetes and explore the mechanism.

METHODS

In this study, streptozotocin (STZ)-induced mice type 1 diabetes model was used. The protein expressions of genes were examined through Western blot analysis. Fasting blood glucose was detected through glucose meter. The plasma insulin was tested through the commercial kit. Hematoxylin and eosin staining was utilized to observe pathological changes of pancreatic tissues. Immunofluorescence assay was performed to evaluate the level of insulin. The levels of pro-inflammatory cytokines in serum were assessed by enzyme-linked-immunosorbent serologic assay. The cell apoptosis was measured through terminal deoxynucleotidyl transferase dUTP nick end labelling assay.

RESULTS

STZ was used to stimulate mice model for type 1 diabetes. At first, both RNF20 and RNF40 expressions were down-regulated in STZ-mediated type 1 diabetes. Additionally, RNF20/RNF40 improved hyperglycemia in STZ-stimulated mice. Moreover, RNF20/RNF40 relieved pancreatic tissue injury in STZ-induced mice. Further experiments found that RNF20/RNF40 rescued the strengthened inflammation mediated by STZ treatment. The cell apoptosis was enhanced in the pancreatic tissues of STZ-triggered mice, but this effect was weakened by overexpression of RNF20/RNF40. Besides, the VDR expression was positively regulated by RNF20/RNF40. Finally, VDR knockdown reversed improved hyperglycemia, inflammation, and cell apoptosis stimulated by overexpression of RNF20/RNF40.

CONCLUSION

Our findings proved that RNF20/RNF40 activated VDR to relieve type 1 diabetes. This work might highlight the functioning of RNF20/RNF40 in the treatment of type 1 diabetes.

Circular RNA in autoimmune diseases: special emphasis on regulation mechanism in RA and SLE

BACKGROUND

Autoimmune diseases are diseases caused by tissue damage caused by the body's immune response to autoantibodies. Circular RNAs (CircRNAs) are a kind of special endogenous non-coding RNA that play a biological role by regulating gene transcription.

METHODS

In this work, we searched the PubMed, Web of Science (SCIE), National Science and Technology Library (NSTL), and ScienceDirect Online (SDOL) databases to summarize the impact of circRNAs on autoimmune diseases, especially the results of circRNAs in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

RESULTS

The study on the function of circRNAs and autoimmune diseases further deepened our understanding of the development and pathogenesis of autoimmune diseases. CircRNAs may act as miRNA sponges to regulate biological processes and affect the occurrence and development of autoimmune diseases. CircRNAs are closely related to the pathogenesis of RA and SLE and may become potential biomarkers for the diagnosis and treatment of RA and SLE.

CONCLUSION

CircRNAs play an important role in the pathogenesis of RA, SLE and other autoimmune diseases, and are expected to provide new biomarkers for the diagnosis and treatment of autoimmune diseases. However, the function and mechanism of circRNAs in autoimmune diseases need more comprehensive research.

Identification of hsa_circRNA_100632 as a novel molecular biomarker for fulminant type 1 diabetes

Objective

Circular RNAs (circRNAs) are associated with diabetes, but their role in fulminant type 1 diabetes (FT1D) is unclear. Thus, we characterized the role of circRNAs in FT1D.

Research design and methods

CircRNA expression profiles were detected in peripheral blood mononuclear cells (PBMCs) of five FT1D patients and five controls using a circRNA microarray. An independent cohort comprised of 40 FT1D cases, 75 type 1 diabetes (T1D) cases, and 115 controls was used to verify the circRNAs using quantitative real-time polymerase chain reaction (qRT-PCR). Spearman's correlation analysis and receiver operating characteristic (ROC) curve analysis were performed to determine the clinical diagnostic capability of circRNAs. Bioinformatics was used to identify potential biological functions and circRNA-miRNA-mRNA interactions.

Results

There were 13 upregulated and 13 downregulated circRNAs in PBMCs of patients with FT1D. Five circRNAs were further verified in a second cohort. Hsa_circRNA_100632 was significantly upregulated in the FT1D and T1D groups. Hsa_circRNA_100632 was differentiated between patients with FT1D and controls [area under the curve (AUC) 0.846; 95% CI 0.776-0.916; P<0.0001] as well as between patients with FT1D and patients with T1D (AUC 0.726; 95% CI 0.633-0.820; P<0.0001). Bioinformatics analysis showed that hsa_circRNA_100632 may be involved in 47 circRNA-miRNA-mRNA signaling pathways associated with diabetes.

Conclusions

CircRNAs were aberrantly expressed in PBMCs of patients with FT1D, and hsa_circRNA_100632 may be a diagnostic marker of FT1D.

Non-coding RNAs: Role in diabetic foot and wound healing

Diabetic foot ulcer (DFU) and poor wound healing are chronic complications in patients with diabetes. The increasing incidence of DFU has resulted in huge pressure worldwide. Diagnosing and treating this condition are therefore of great importance to control morbidity and improve prognosis. Finding new markers with potential diagnostic and therapeutic utility in DFU has gathered increasing interest. Wound healing is a process divided into three stages: Inflammation, proliferation, and regeneration. Non-coding RNAs (ncRNAs), which are small protected molecules transcribed from the genome without protein translation function, have emerged as important regulators of diabetes complications. The deregulation of ncRNAs may be linked to accelerated DFU development and delayed wound healing. Moreover, ncRNAs can be used for therapeutic purposes in diabetic wound healing. Herein, we summarize the role of microRNAs, long ncRNAs, and circular RNAs in diverse stages of DFU wound healing and their potential use as novel therapeutic targets.

Differential Expression and Bioinformatics Analysis of Plasma-Derived Exosomal circRNA in Type 1 Diabetes Mellitus

Backgrounds

Both exosome and circular RNA (circRNA) have been reported to participate in the pathogenesis of type 1 diabetes mellitus (T1DM). However, the exact role of exosomal circRNA in T1DM is largely unknown. Here, we identified the exosomal circRNA expression profiles in the plasma of T1DM patients and explored their potential function using bioinformatics analysis. Material and Methods. Exosomes were extracted by the size exclusion chromatography method from plasma of 10 T1DM patients and 10 age- and sex- matched control subjects. Illumina Novaseq6000 platform was used to detect the exosomal circRNA expression profiles. Multiple bioinformatics analysis was applied to investigate the potential biological functions of exosomal circRNAs.

Results

A total of 784 differentially expressed exosomal circRNAs have been identified in T1DM patients, of which 528 were upregulated and 256 were downregulated. Gene Ontology analysis enriched terms such as protein ubiquitination involved in ubiquitin-dependent protein catabolic protein (GO:0042787), membrane (GO:0016020), and GTPase activator activity (GO:0005096). The most enriched pathway in Kyoto Encyclopedia of Genes and Genomes was ubiquitin-mediated proteolysis (ko04120). The miRNA-targeting prediction method was used to identify the miRNAs that bind to circRNAs, and circRNA-miRNA-mRNA pathways were constructed, indicating that interactions between circRNA, miRNA, and gene might be involved in the disease progression.

Conclusions

The present study identified the exosomal circRNA expression profiles in T1DM for the first time. Our results threw novel insights into the molecular mechanisms of T1DM.

Circular RNAs in diabetes and its complications: Current knowledge and future prospects

A novel class of non-coding RNA transcripts called circular RNAs (circRNAs) have been the subject of significant recent studies. Accumulating evidence points that circRNAs play an important role in the cellular processes, inflammatory expression, and immune responses through sponging miRNA, binding, or translating in proteins. Studies have found that circRNAs are involved in the physiologic and pathologic processes of diabetes. There has been an increased focus on the relevance of between abnormal circRNA expression and the development and progression of various types of diabetes and diabetes-related diseases. These circRNAs not only serve as promising diagnostic and prognostic molecular biomarkers, but also have important biological roles in islet cells, diabetes, and its complications. In addition, many circRNA signaling pathways have been found to regulate the occurrence and development of diabetes. Here we comprehensively review and discuss recent advances in our understanding of the physiologic function and regulatory mechanisms of circRNAs on pancreatic islet cells, different subtypes in diabetes, and diabetic complications.

Circ_0060077 Knockdown Alleviates High-Glucose-Induced Cell Apoptosis, Oxidative Stress, Inflammation and Fibrosis in HK-2 Cells via miR-145-5p/VASN Pathway

The involvement of circular RNAs (circRNAs) in the progression of diabetic nephropathy (DN) has been reported. However, the functions of circ_0060077 in DN remain unclear. HK-2 cells were treated with high glucose (HG) to establish DN cell model. Quantitative real-time polymerase chain reaction (qRT-PCR) was proceeded to determine the levels of circ_0060077, microRNA-145-5p (miR-145-5p) and vasorin (VASN). Cell counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay and colony formation assay were conducted to assess cell proliferation ability. Flow cytometry analysis was employed for cell apoptosis. The oxidative stress level was evaluated by commercial kits. Enzyme-linked immunosorbent assay (ELISA) was adopted to examine the concentrations of inflammatory factors. Western blot assay was utilized for protein levels. Dual-luciferase reporter assay and RNA pull-down assay were manipulated to analyze the relationships among circ_0060077, miR-145-5p and VASN. Circ_0060077 level was increased in DN patients and HG-stimulated HK-2 cells. Circ_0060077 knockdown ameliorated the inhibitory effect of HG on HK-2 cell proliferation and the promotional effects on cell apoptosis, oxidative stress, inflammation and fibrosis. MiR-145-5p was identified as the target for circ_0060077 and miR-145-5p inhibition ameliorated the effect of circ_0060077 silencing on HG-induced HK-2 cell injury. Moreover, miR-145-5p directly bound to VASN. Overexpression of miR-145-5p facilitated cell proliferation and repressed apoptosis, oxidative injury, inflammation and fibrosis in HG-induced HK-2 cells by targeting VASN. Circ_0060077 silencing protected HK-2 cells from HG-induced damage by regulating miR-145-5p/VASN axis.

Type 1 Diabetes Mellitus-Related circRNAs Regulate CD4+ T Cell Functions

Circular RNAs (circRNAs) participate in development of malignancies through its active role as a “miRNA sponge.” Their roles in type 1 diabetes mellitus (T1DM) pathogenesis are elusive. Here, the important role of circRNAs in T1DM was explored. circRNA profiling was performed for isolated CD4+ T cells from blood of T1DM and healthy volunteers. There were 257 differentially expressed circRNAs. Only three upregulated DEcircRNAs (hsa_circ_0000324, hsa_circ_0001853, and hsa_circ_0068797) were consistent with the GEO database. Through KEGG analyses, it was found that the three DEcircRNAs were associated with 11 miRNAs and 8 immune-related target genes (mRNA). Further analysis found that four miRNAs, two circRNAs, and four mRNAs were associated with nine circRNA-miRNA-mRNA networks. This confirmed the requirements of sponge mechanisms. The qRT-PCR analysis revealed that circRNA000324/miRNA675-5p/MAPK14 and circRNA000324/miRNA-675-5p/SYK may be potential mechanisms in regulation of differentiation and proliferation of CD4+ T cell in patients with T1DM. Therefore, targeting circRNA to regulate cellular immune responses by regulating CD4+ T cell differentiation may be a new strategy for the treatment of T1DM.

miR-199a: A Tumor Suppressor with Noncoding RNA Network and Therapeutic Candidate in Lung Cancer

Lung cancer is the leading cause of cancer death worldwide. miR-199a, which has two mature molecules: miR-199a-3p and miR-199a-5p, plays an important biological role in the genesis and development of tumors. We collected recent research results on lung cancer and miR-199a from Google Scholar and PubMed databases. The biological functions of miR-199a in lung cancer are reviewed in detail, and its potential roles in lung cancer diagnosis and treatment are discussed. With miR-199a as the core point and a divergence outward, the interplay between miR-199a and other ncRNAs is reviewed, and a regulatory network covering various cancers is depicted, which can help us to better understand the mechanism of cancer occurrence and provide a means for developing novel therapeutic strategies. In addition, the current methods of diagnosis and treatment of lung cancer are reviewed. Finally, a conclusion was drawn: miR-199a inhibits the development of lung cancer, especially by inhibiting the proliferation, infiltration, and migration of lung cancer cells, inhibiting tumor angiogenesis, increasing the apoptosis of lung cancer cells, and affecting the drug resistance of lung cancer cells. This review aims to provide new insights into lung cancer therapy and prevention.

The Role of Non-Coding RNAs in the Pathogenesis of Parkinson’s Disease: Recent Advancement

Parkinson’s disease (PD) is a prevalent neurodegenerative aging disorder that manifests as motor and non-motor symptoms, and its etiopathogenesis is influenced by non-coding RNAs (ncRNAs). Signal pathway and gene sequence studies have proposed that alteration of ncRNAs is relevant to the occurrence and development of PD. Furthermore, many studies on brain tissues and body fluids from patients with PD indicate that variations in ncRNAs and their target genes could trigger or exacerbate neurodegenerative pathogenesis and serve as potential non-invasive biomarkers of PD. Numerous ncRNAs have been considered regulators of apoptosis, α-syn misfolding and aggregation, mitochondrial dysfunction, autophagy, and neuroinflammation in PD etiology, and evidence is mounting for the determination of the role of competing endogenous RNA (ceRNA) mechanisms in disease development. In this review, we discuss the current knowledge regarding the regulation and function of ncRNAs as well as ceRNA networks in PD pathogenesis, focusing on microRNAs, long ncRNAs, and circular RNAs to increase the understanding of the disease and propose potential target identification and treatment in the early stages of PD.

Targeting protein phosphatases for the treatment of inflammation-related diseases: From signaling to therapy

Inflammation is the common pathological basis of autoimmune diseases, metabolic diseases, malignant tumors, and other major chronic diseases. Inflammation plays an important role in tissue homeostasis. On one hand, inflammation can sense changes in the tissue environment, induce imbalance of tissue homeostasis, and cause tissue damage. On the other hand, inflammation can also initiate tissue damage repair and maintain normal tissue function by resolving injury and restoring homeostasis. These opposing functions emphasize the significance of accurate regulation of inflammatory homeostasis to ameliorate inflammation-related diseases. Potential mechanisms involve protein phosphorylation modifications by kinases and phosphatases, which have a crucial role in inflammatory homeostasis. The mechanisms by which many kinases resolve inflammation have been well reviewed, whereas a systematic summary of the functions of protein phosphatases in regulating inflammatory homeostasis is lacking. The molecular knowledge of protein phosphatases, and especially the unique biochemical traits of each family member, will be of critical importance for developing drugs that target phosphatases. Here, we provide a comprehensive summary of the structure, the "double-edged sword" function, and the extensive signaling pathways of all protein phosphatases in inflammation-related diseases, as well as their potential inhibitors or activators that can be used in therapeutic interventions in preclinical or clinical trials. We provide an integrated perspective on the current understanding of all the protein phosphatases associated with inflammation-related diseases, with the aim of facilitating the development of drugs that target protein phosphatases for the treatment of inflammation-related diseases.

Past, Present and Future: The Relationship Between Circular RNA and Immunity

The immune system has evolved since the birth of humans. However, immune-related diseases have not yet been overcome due to the lack of expected indicators and targeting specificity of current medical technology, subjecting patients to very uncomfortable physical and mental experiences and high medical costs. Therefore, the requirements for treatments with higher specificity and indicative ability are raised. Fortunately, the discovery of and continuous research investigating circular RNAs (circRNAs) represent a promising method among numerous methods. Although circRNAs wear regarded as metabolic wastes when discovered, as a type of noncoding RNA (ncRNA) with a ring structure and wide distribution range in the human body, circRNAs shine brilliantly in medical research by virtue of their special nature and structure-determined functions, such as high stability, wide distribution, high detection sensitivity, acceptable reproducibility and individual differences. Based on research investigating the role of circRNAs in immunity, we systematically discuss the hotspots of the roles of circRNAs in immune-related diseases, including expression profile analyses, potential biomarker research, ncRNA axis/network construction, impacts on phenotypes, therapeutic target seeking, maintenance of nucleic acid stability and protein binding research. In addition, we summarize the current situation of and problems associated with circRNAs in immune research, highlight the applications and prospects of circRNAs in the treatment of immune-related diseases, and provide new insight into future directions and new strategies for laboratory research and clinical applications.

miR-199a-5p Plays a Pivotal Role on Wound Healing via Suppressing VEGFA and ROCK1 in Diabetic Ulcer Foot

Diabetes mellitus (DM) is a growing health problem. As a common complication of DM, diabetic foot ulcer (DFU) results in delayed wound healing and is a leading cause of nontraumatic amputation. miR-199a-5p, a short noncoding RNA, had abnormal expression in DFU wound tissues. The expression of miR-199a-5p was significantly increased in DFU wound tissues, skin tissues of diabetic rats, and high glucose-induced cells. Vascular endothelial growth factor A (VEGFA) and Rho-associated kinase 1 (ROCK1) are directly targets of miR-199a-5p. Inhibiting the expression of miR-199a-5p alleviated the inhibition of VEGFA and ROCK1, thereby rescued impaired proliferation and migration of HG-induced cells, and restored the normal function of the cells to some extent. In diabetic rats, inhibition of miR-199a-5p significantly increased the expression of VEGFA and ROCK1, significantly promoted wound healing, and rescued impaired wound healing. miR-199a-5p and its targets showed therapeutic effect on diabetic wounds.

Circ-ZEB1 promotes PIK3CA expression by silencing miR-199a-3p and affects the proliferation and apoptosis of hepatocellular carcinoma

BACKGROUND

Although the prognostic outcomes of liver cancer (LC) cases have improved with the advancement in diagnostic technology and treatment methods, the transferability and recurrence of HCC and the 5-year and 10-year survival rates of patients have remained unsatisfactory. As a result, there is a need for more accurate diagnostic indicators that can detect liver cancer early, effectively improving the prognosis of patients. Whole-genome sequencing (WGS) revealed that circ-ZEB1 and PIK3CA are highly expressed in HCC tissues, whereas miR-199a-3p is significantly downregulated in HCC. Multiple databases search and biological analysis revealed that elevated expression of circ-ZEB1 and PIK3CA was related to poor prognosis of HCC. In vitro and in vivo studies revealed that upregulated levels of PIK3CA and circ-ZEB1 were closely associated with HCC proliferation and apoptosis. Based on these results, we believe that circ-ZEB1 and PIK3CA could be used as biomarkers to diagnose and treat patients with HCC. More importantly, circ-ZEB1 can promotes the expression of PIK3CA by silencing miR-199a-3p and affecting the progression of HCC.

METHODS AND RESULTS

Postoperative specimens from 56 patients with HCC who had not undergone chemotherapy from 2015 to 2018 were collected from the Department of Hepatobiliary Surgery, Second Affiliated Hospital of Nanchang University. WGS revealed differential expression of genes in HCC. Furthermore, RT-qPCR detected the expression of circ-ZEB1, miR-199a-3p, and PIK3CA in HCC tissues. MTT, EdU, and plate cloning experiments were conducted to detect cell proliferation, whereas flow cytometry analysis was used to detect apoptosis. FISH was used to co-localize circ-ZEB1 and miR-199a-3p, and biotin-coupled probe pull-down assay was used to detect the specific binding of circ-ZEB1 and miR-199a-3p. The dual-luciferase report assay detected the association of miR-199a-3p with PIK3CA. Western blotting was used to study the expression of PIK3CA protein. Circ-ZEB1 and PIK3CA were upregulated in HCC and predicted a poor prognosis. MiR-199a-3p showed low expression in HCC, whereas downregulation of circ-ZEB1 reduced HCC cell proliferation and promoted cell apoptosis. MiR-199a-3p blocked the effect of circ-ZEB1 on HCC. Circ-ZEB1 served as a biomarker of HCC. Circ-ZEB1 promoted the expression of PIK3CA by silencing miR-199a-3p to affect the progress of HCC.

CONCLUSIONS

Circ-ZEB1 promoted the expression of PIK3CA by depleting miR-199a-3p, thereby affecting HCC proliferation and apoptosis.

Research Advances in the Roles of Circular RNAs in Pathophysiology and Early Diagnosis of Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) refers to different degrees of glucose tolerance abnormalities that occur during pregnancy or are discovered for the first time, which can have a serious impact on the mother and the offspring. The screening of GDM mainly relies on the oral glucose tolerance test (OGTT) at 24–28 weeks of gestation. The early diagnosis and intervention of GDM can greatly improve adverse pregnancy outcomes. However, molecular markers for early prediction and diagnosis of GDM are currently lacking. Therefore, looking for GDM-specific early diagnostic markers has important clinical significance for the prevention and treatment of GDM and the management of subsequent maternal health. Circular RNA (circRNA) is a new type of non-coding RNA. Recent studies have found that circRNAs were involved in the occurrence and development of malignant tumors, metabolic diseases, cardiovascular and cerebrovascular diseases, etc., and could be used as the molecular marker for early diagnosis. Our previous research showed that circRNAs are differentially expressed in serum of GDM pregnant women in the second and third trimester, placental tissues during cesarean delivery, and cord blood. However, the mechanism of circular RNA in GDM still remains unclear. This article focuses on related circRNAs involved in insulin resistance and β-cell dysfunction, speculating on the possible role of circRNAs in the pathophysiology of GDM under the current research context, and has the potential to serve as early molecular markers for the diagnosis of GDM.

Non-coding RNAs in diabetes mellitus and diabetic cardiovascular disease

More than 10% of the world's population already suffers from varying degrees of diabetes mellitus (DM), but there is still no cure for the disease. Cardiovascular disease (CVD) is one of the most common and dangerous of the many health complications that can be brought on by DM, and has become the leading cause of death in people with diabetes. While research on DM and associated CVD is advancing, the specific mechanisms of their development are still unclear. Given the threat of DM and CVD to humans, the search for new predictive markers and therapeutic ideas is imminent. Non-coding RNAs (ncRNAs) have been a popular subject of research in recent years. Although they do not encode proteins, they play an important role in living organisms, and they can cause disease when their expression is abnormal. Numerous studies have observed aberrant ncRNAs in patients with DM complications, suggesting that they may play an important role in the development of DM and CVD and could potentially act as biomarkers for diagnosis. There is additional evidence that treatment with existing drugs for DM, such as metformin, alters ncRNA expression levels, suggesting that regulation of ncRNA expression may be a key mechanism in future DM treatment. In this review, we assess the role of ncRNAs in the development of DM and CVD, as well as the evidence for ncRNAs as potential therapeutic targets, and make use of bioinformatics to analyze differential ncRNAs with potential functions in DM.

Circular RNAs in diabetes mellitus and its complications

Diabetes mellitus (DM) is an endocrine disorder characterized by a relative or absolute lack of insulin due to the dysfunction or destruction of β-cells. DM is one of the fastest growing challenges to global health in the 21^st century and places a tremendous burden on affected individuals and their families and countries. Although insulin and antidiabetic drugs have been used to treat DM, a radical cure for the disease is unavailable. The pathogenesis of DM remains unclear. Emerging roles of circular RNAs (circRNAs) in DM have become a subject of global research. CircRNAs have been verified to participate in the onset and progression of DM, implying their potential roles as novel biomarkers and treatment tools. In the present review, we briefly introduce the characteristics of circRNAs. Next, we focus on specific roles of circRNAs in type 1 diabetes mellitus, type 2 diabetes mellitus, gestational diabetes mellitus and diabetes-associated complications.

Intricate crosstalk between MYB and noncoding RNAs in cancer

MYB is often overexpressed in malignant tumors and plays a carcinogenic role in the initiation and development of cancer. Deletion of the MYB regulatory C-terminal domain may be a driving mutation leading to tumorigenesis, therefore, different tumor mechanisms produce similar MYB proteins. As MYB is a transcription factor, priority has been given to identifying the genes that it regulates. All previous attention has been focused on protein-coding genes. However, an increasing number of studies have suggested that MYB can affect the complexity of cancer progression by regulating tumor-associated noncoding RNAs (ncRNAs), such as microRNAs, long-non-coding RNAs and circular RNAs. ncRNAs can regulate the expression of numerous downstream genes at the transcription, RNA processing and translation levels, thereby having various biological functions. Additionally, ncRNAs play important roles in regulating MYB expression. This review focuses on the intricate crosstalk between oncogenic MYB and ncRNAs, which play a pivotal role in tumorigenesis, including proliferation, apoptosis, angiogenesis, metastasis, senescence and drug resistance. In addition, we discuss therapeutic strategies for crosstalk between MYB and ncRNAs to prevent the occurrence and development of cancer.

Hsa-miR-199a-5p Protect Cell Injury in Hypoxia Induces Myocardial Cells Via Targeting HIF1α

Myocardial infarction (MI) is one of the most common global diseases. Recently, microRNA 199a-5p (miR-199a-5p) has been recognized as a vital regulator in several human diseases. Nevertheless, the function of miR-199a-5p and the associated downstream molecular mechanisms in myocardial injury remain undescribed. Here, we assessed the relative expression of miR-199a-5p in an oxidative stress injury model of human myocardial cells. The effects of miR-199a-5p on myocardial cell viability were determined by cell counting kit-8 (CCK-8), terminal deoxynucleotidyl transferase UTP nick end labeling (TUNEL), flow cytometry, and western blot assays. Online bioinformatic analysis was used to predict the aim of miR-199a-5p in cardiomyocyte injury, which was confirmed by dual-luciferase reporter assays. miR-199a-5p increased the growth rate of cardiomyocytes after treatment with a hypoxic environment. miR-199a-5p acted as an inhibitor directly targeted hypoxia-inducible factor-1 (HIF1α) expression, which was higher in the cardiomyocyte injury model than that in healthy myocardial cells. Upregulated HIF1α expression abolished miR-199a-5p-induced cell proliferation in the cardiomyocyte hypoxia model. Our results suggest that miR-199a-5p is a potential prognostic biomarker in myocardial damage.

Revealing New Landscape of Turbot (Scophthalmus maximus) Spleen Infected with Aeromonas salmonicida through Immune Related circRNA-miRNA-mRNA Axis

Simple Summary

In this study, the expression of circRNAs, miRNAs, and mRNA in the immune organs spleen of turbot (Scophthalmus maximus) infected with Aeromonas salmonicida was analyzed by high-throughput sequencing, and circRNA-miRNA-mRNA network was constructed, so as to explore the function of non-coding RNA in the immune system of teleost. A total of 119, 140, and 510 differential expressed circRNAs, miRNAs, and mRNAs were identified in the infected groups compared with the uninfected group. The qRT-PCR verified the reliability and accuracy of the Illumina sequencing data. Fifteen triple networks of circRNA-miRNA-mRNA were presented in the form of “up (circRNA)-down (miRNA)-up (mRNA)” or “down-up-down”. Immune-related genes were also found in these networks. These results indicate that circRNAs and miRNAs may regulate the expression of immune-related genes through the circRNA-miRNA-mRNA regulatory network and thus participate in the immune response of turbot spleen after pathogen infection.

Abstract

Increasing evidence suggests that non-coding RNAs (ncRNA) play an important role in a variety of biological life processes by regulating gene expression at the transcriptional and post-transcriptional levels. Turbot (Scophthalmus maximus) has been threatened by various pathogens. In this study, the expression of circular RNAs (circRNAs), microRNAs (miRNAs), and mRNA in the immune organs spleen of turbot infected with Aeromonas salmonicida was analyzed by high-throughput sequencing, and a circRNA-miRNA-mRNA network was constructed, so as to explore the function of non-coding RNA in the immune system of teleost. Illumina sequencing was performed on the uninfected group and infected group. A total of 119 differential expressed circRNAs (DE-circRNAs), 140 DE-miRNAs, and 510 DE-mRNAs were identified in the four infected groups compared with the uninfected group. Most DE-mRNAs and the target genes of DE-ncRNAs were involved in immune-related pathways. The quantitative real-time PCR (qRT-PCR) results verified the reliability and accuracy of the high-throughput sequencing data. Ninety-six differentially expressed circRNA-miRNA-mRNA regulatory networks were finally constructed. Among them, 15 circRNA-miRNA-mRNA were presented in the form of “up (circRNA)-down (miRNA)-up (mRNA)” or “down-up-down”. Immune-related genes gap junction CX32.2, cell adhesion molecule 3, and CC chemokine were also found in these networks. These results indicate that ncRNA may regulate the expression of immune-related genes through the circRNA-miRNA-mRNA regulatory network and thus participate in the immune response of turbot spleen after pathogen infection.

Implication of epigenetic factors in the pathogenesis of type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease that resulted from the severe destruction of the insulin-producing β cells in the pancreases of individuals with a genetic predisposition. Genome-wide studies have identified HLA and other risk genes associated with T1D susceptibility in humans. However, evidence obtained from the incomplete concordance of diabetes incidence among monozygotic twins suggests that environmental factors also play critical roles in T1D pathogenesis. Epigenetics is a rapidly growing field that serves as a bridge to link T1D risk genes and environmental exposures, thereby modulating the expression of critical genes relevant to T1D development beyond the changes of DNA sequences. Indeed, there is compelling evidence that epigenetic changes induced by environmental insults are implicated in T1D pathogenesis. Herein, we sought to summarize the recent progress in terms of epigenetic mechanisms in T1D initiation and progression, and discuss their potential as biomarkers and therapeutic targets in the T1D setting.

Circular RNAs as Novel Regulators of β-Cell Functions under Physiological and Pathological Conditions

Circular RNAs (circRNAs) constitute a large class of non-coding RNAs characterized by a covalently closed circular structure. They originate during mRNA maturation through a modification of the splicing process and, according to the included sequences, are classified as Exonic, Intronic, or Exonic-Intronic. CircRNAs can act by sequestering microRNAs, by regulating the activity of specific proteins, and/or by being translated in functional peptides. There is emerging evidence indicating that dysregulation of circRNA expression is associated with pathological conditions, including cancer, neurological disorders, cardiovascular diseases, and diabetes. The aim of this review is to provide a comprehensive and updated view of the most abundant circRNAs expressed in pancreatic islet cells, some of which originating from key genes controlling the differentiation and the activity of insulin-secreting cells or from diabetes susceptibility genes. We will particularly focus on the role of a group of circRNAs that contribute to the regulation of β-cell functions and that display altered expression in the islets of rodent diabetes models and of type 2 diabetic patients. We will also provide an outlook of the unanswered questions regarding circRNA biology and discuss the potential role of circRNAs as biomarkers for β-cell demise and diabetes development.

Understanding Competitive Endogenous RNA Network Mechanism in Type 1 Diabetes Mellitus Using Computational and Bioinformatics Approaches

BACKGROUND

Type 1 diabetes mellitus (T1DM), an autoimmune disease with a genetic tendency, has an increasing prevalence. Long non-coding RNA (lncRNA) and circular RNA (circRNA) are receiving increasing attention in disease pathogenesis. However, their roles in T1DM are poorly understood. The present study aimed at identifying signature lncRNAs and circRNAs and investigating their roles in T1DM using the competing endogenous RNA (ceRNA) network analysis.

METHODS

The T1DM expression profile was downloaded from Gene Expression Omnibus (GEO) database to identify the differentially expressed circRNAs, lncRNAs, and mRNAs. The biological functions of these differentially expressed circRNAs, lncRNAs, and mRNAs were analyzed by the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. Targeting relationships of circRNA-miRNA, lncRNA-miRNA, and miRNA-mRNA were predicted, and the circRNA-lncRNA-miRNA-mRNA ceRNA regulatory network was established. Finally, qRT-PCR was applied to identify the effect of hsa_circ_0002202 inhibition on the IFN-I induced macrophage inflammation.

RESULTS

A total of 178 circRNAs, 404 lncRNAs, and 73 mRNAs were identified to be abnormally expressed in T1DM samples. Functional enrichment analysis results indicated that the differentially expressed genes were mainly enriched in extracellular matrix components and macrophage activation. CeRNA regulatory network showed that circRNAs and lncRNAs regulate mRNAs through integrate multiple miRNAs. In addition, in vitro experiments showed that hsa_circ_0002202 inhibition suppressed the type I interferon (IFN-I)-induced macrophage inflammation.

CONCLUSION

In the present study, the circRNA-lncRNA-miRNA-mRNA ceRNA regulatory network in T1DM was established for the first time. We also found that hsa_circ_0002202 inhibition suppressed the IFN-I-induced macrophage inflammation. Our study may lay a foundation for future studies on the ceRNA regulatory network in T1DM.