Upregulation of miR-665 promotes apoptosis and colitis in inflammatory bowel disease by repressing the endoplasmic reticulum stress components XBP1 and ORMDL3

miR-155 promotes m6A modification of SOX2 mRNA through targeted regulation of HIF-1α and delays wound healing in diabetic foot ulcer in vitro models

OBJECTIVE

Diabetic foot ulcers (DFU) are one of the most destructive complications of diabetes mellitus. The aim of this study was to link miR-155 and SOX2 with DFU to explore the regulation of wound healing by DFU and its potential mechanism.

METHODS

Human keratinocytes (HaCaT) were induced with advanced glycation end products (AGEs) to construct DFU models in vitro. AGE-induced HaCaT cells were subjected to CCK-8 assays, flow cytometry, and wound healing assays to evaluate cell proliferation, apoptosis, and migration capacity, respectively. RT-qPCR and Western blotting were used to determine gene and protein expression levels, respectively. N6-methyladenosine (M6A) levels in total RNA were assessed using an M6A methylation quantification kit.

RESULTS

Our results suggested that the inhibition of miR-155 promoted wound healing in an in vitro DFU model, while the knockdown of HIF-1α reversed this process, and that HIF-1α was a target protein of miR-155. In addition, knockdown of HIF-1α promoted the m6A level of SOX2 mRNA, inhibited the expression of SOX2, and inhibited the activation of the EGFR/MEK/ERK signaling pathway, thus inhibiting the proliferation and migration of HaCaT cells and promoting the apoptosis of HaCaT cells, while overexpression of SOX2 reversed this effect. We also found that METTL3 knockdown had the opposite effect of HIF-1α knockdown.

CONCLUSIONS

Inhibition of miR-155 promoted the expression of HIF-1α and attenuated the m6A modification of SOX2 mRNA, thereby promoting the expression of SOX2 and activating the downstream EGFR/MEK/ERK signaling pathway to promote wound healing in an in vitro DFU model.

The miRNA Landscape in Crohn's disease: Implications for novel therapeutic approaches and interactions with Existing therapies

MicroRNAs (miRNAs), which are non-coding RNAs consisting of 18-24 nucleotides, play a crucial role in the regulatory pathways of inflammatory diseases. Several recent investigations have examined the potential role of miRNAs in forming Crohn's disease (CD). It has been suggested that miRNAs serve as diagnostics for both fibrosis and inflammation in CD due to their involvement in the mechanisms of CD aggravation and fibrogenesis. More information on CD pathophysiology could be obtained by identifying the miRNAs concerned with CD and their target genes. These findings have prompted several in vitro and in vivo investigations into the putative function of miRNAs in CD treatment. Although there are still many unanswered questions, the growing body of evidence has brought miRNA-based therapy one step closer to clinical practice. This extensive narrative study offers a concise summary of the most current advancements in CD. We go over what is known about the diagnostic and therapeutic benefits of miRNA mimicry and inhibition so far, and we see what additional miRNA family targets could be useful for treating CD-related inflammation and fibrosis.

Evaluation of autophagy related ATG4B gene, protein and miR-655-3p expression levels in endometrial cancer and hyperplasia

OBJECTIVE

The pathogenesis of endometrial cancer (EC) and hyperplasia is complex and poorly understood. Autophagy has emerged as a crucial aspect of this process.

METHODS

This study examines the role of autophagy in the pathogenesis of EC and hyperplasia by investigating the expression of the autophagy-related 4B cysteine peptidase (ATG4B) gene, protein, and miR-665-3p levels in patients compared to a control group. This cross-sectional case control study analyzed 90 endometrial tissues, including 30 tumors, 30 normal controls, and 30 hyperplasia, using quantitative reverse transcription polymerase chain reaction and Western blot to assess ATG4B gene and protein levels.

RESULTS

Higher ATG4B gene expression levels were found in the endometrial tissue of EC patients than in hyperplasia patients and controls. Furthermore, protein levels of ATG4B were also higher in EC and hyperplasia patients than in controls. ATG4B gene expression and protein levels were positively correlated in EC patients. However, in EC patients, miR-655-3p showed a significant negative correlation with the ATG4B gene and protein levels.

CONCLUSION

ATG4B gene and protein expression is elevated in EC tissue, suggesting their role as a tumor promoter. Evaluating their levels could serve as markers for monitoring EC progression and prognosis.

The Contribution of Genetic and Epigenetic Factors: An Emerging Concept in the Assessment and Prognosis of Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) represents heterogeneous and relapsing intestinal conditions with a severe impact on the quality of life of individuals and a continuously increasing prevalence. In recent years, the development of sequencing technology has provided new means of exploring the complex pathogenesis of IBD. An ideal solution is represented by the approach of precision medicine that investigates multiple cellular and molecular interactions, which are tools that perform a holistic, systematic, and impartial analysis of the genomic, transcriptomic, proteomic, metabolomic, and microbiomics sets. Hence, it has led to the orientation of current research towards the identification of new biomarkers that could be successfully used in the management of IBD patients. Multi-omics explores the dimension of variation in the characteristics of these diseases, offering the advantage of understanding the cellular and molecular mechanisms that affect intestinal homeostasis for a much better prediction of disease development and choice of treatment. This review focuses on the progress made in the field of prognostic and predictive biomarkers, highlighting the limitations, challenges, and also the opportunities associated with the application of genomics and epigenomics technologies in clinical practice.

Cellular Senescence and Extracellular Vesicles in the Pathogenesis and Treatment of Obesity-A Narrative Review

This narrative review explores the pathophysiology of obesity, cellular senescence, and exosome release. When exposed to excessive nutrients, adipocytes develop mitochondrial dysfunction and generate reactive oxygen species with DNA damage. This triggers adipocyte hypertrophy and hypoxia, inhibition of adiponectin secretion and adipogenesis, increased endoplasmic reticulum stress and maladaptive unfolded protein response, metaflammation, and polarization of macrophages. Such feed-forward cycles are not resolved by antioxidant systems, heat shock response pathways, or DNA repair mechanisms, resulting in transmissible cellular senescence via autocrine, paracrine, and endocrine signaling. Senescence can thus affect preadipocytes, mature adipocytes, tissue macrophages and lymphocytes, hepatocytes, vascular endothelium, pancreatic β cells, myocytes, hypothalamic nuclei, and renal podocytes. The senescence-associated secretory phenotype is closely related to visceral adipose tissue expansion and metaflammation; inhibition of SIRT-1, adiponectin, and autophagy; and increased release of exosomes, exosomal micro-RNAs, pro-inflammatory adipokines, and saturated free fatty acids. The resulting hypernefemia, insulin resistance, and diminished fatty acid β-oxidation lead to lipotoxicity and progressive obesity, metabolic syndrome, and physical and cognitive functional decline. Weight cycling is related to continuing immunosenescence and exposure to palmitate. Cellular senescence, exosome release, and the transmissible senescence-associated secretory phenotype contribute to obesity and metabolic syndrome. Targeted therapies have interrelated and synergistic effects on cellular senescence, obesity, and premature aging.

Targeting programmed cell death in inflammatory bowel disease through natural products: New insights from molecular mechanisms to targeted therapies

Inflammatory bowel disease (IBD) is an autoimmune disorder primarily characterized by intestinal inflammation and recurrent ulceration, leading to a compromised intestinal barrier and inflammatory infiltration. This disorder's pathogenesis is mainly attributed to extensive damage or death of intestinal epithelial cells, along with abnormal activation or impaired death regulation of immune cells and the release of various inflammatory factors, which contribute to the inflammatory environment in the intestines. Thus, maintaining intestinal homeostasis hinges on balancing the survival and functionality of various cell types. Programmed cell death (PCD) pathways, including apoptosis, pyroptosis, autophagy, ferroptosis, necroptosis, and neutrophil extracellular traps, are integral in the pathogenesis of IBD by mediating the death of intestinal epithelial and immune cells. Natural products derived from plants, fruits, and vegetables have shown potential in regulating PCD, offering preventive and therapeutic avenues for IBD. This article reviews the role of natural products in IBD treatment by focusing on targeting PCD pathways, opening new avenues for clinical IBD management.

Decoding contextual crosstalk: revealing distinct interactions between non-coding RNAs and unfolded protein response in breast cancer

Breast cancer is significantly influenced by endoplasmic reticulum (ER) stress, impacting both its initiation and progression. When cells experience an accumulation of misfolded or unfolded proteins, they activate the unfolded protein response (UPR) to restore cellular balance. In breast cancer, the UPR is frequently triggered due to challenging conditions within tumors. The UPR has a dual impact on breast cancer. On one hand, it can contribute to tumor growth by enhancing cell survival and resistance to programmed cell death in unfavorable environments. On the other hand, prolonged and severe ER stress can trigger cell death mechanisms, limiting tumor progression. Furthermore, ER stress has been linked to the regulation of non-coding RNAs (ncRNAs) in breast cancer cells. These ncRNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), play essential roles in cancer development by influencing gene expression and cellular processes. An improved understanding of how ER stress and ncRNAs interact in breast cancer can potentially lead to new treatment approaches. Modifying specific ncRNAs involved in the ER stress response might interfere with cancer cell survival and induce cell death. Additionally, focusing on UPR-associated proteins that interact with ncRNAs could offer novel therapeutic possibilities. Therefore, this review provides a concise overview of the interconnection between ER stress and ncRNAs in breast cancer, elucidating the nuanced effects of the UPR on cell fate and emphasizing the regulatory roles of ncRNAs in breast cancer progression.

Antagomir of miR-31-5p modulates macrophage polarization via the AMPK/SIRT1/NLRP3 signaling pathway to protect against DSS-induced colitis in mice

Macrophage-driven immune dysfunction of the intestinal mucosa is involved in the pathophysiology of ulcerative colitis (UC). Emerging evidence indicates that there is an elevation in miR-31-5p levels in UC, which is accompanied by a downregulation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) expression. Nevertheless, the precise influence of miR-31-5p on macrophage polarization and the integrity of the intestinal epithelial barrier in UC remains to be fully elucidated. This study explored the role of miR-31-5p and AMPK in UC through a bioinformatics investigation. It investigated the potential of miR-31-5p antagomir to shift macrophages from pro-inflammatory M1 phenotype to anti-inflammatory M2 phenotype and enhance the intestinal mucosal barrier in DSS-induced UC mice. Additionally, RAW264.7 cells stimulated with LPS were employed to confirm the reversal of miR-31-5p antagomir's therapeutic effect under AMPK inhibition. The findings demonstrated that miR-31-5p antagomir penetrated colonic tissues and ameliorated DSS-induced experimental colitis. Transformation of spleen and mesenteric lymph node macrophages from M1 to M2 type was seen in the DSS+miR-31-5p antagomir group. AMPK/Sirt1 expression increased while NLRP3 expression decreased. Expression of M2-related genes and proteins was enhanced and that of the M1 phenotype suppressed. Tight junction proteins, ZO-1 and occludin, were increased. The therapeutic effects of miR-31-5p antagomir transfection into RAW264.7 cells were repressed when AMPK expression was inhibited. Therefore, our results suggest that suppression of miR-31-5p expression transformed macrophages from M1 to M2, ameliorated inflammation and repaired the intestinal epithelium to alleviate DSS-induced colitis. AMPK/Sirt1/NLRP3 was involved.

The emerging role of miRNAs in myocardial infarction: From molecular signatures to therapeutic targets

Globally, myocardial infarction (MI) and other cardiovascular illnesses have long been considered the top killers. Heart failure and mortality are the results of myocardial apoptosis, cardiomyocyte fibrosis, and cardiomyocyte hypertrophy, all of which are caused by MI. MicroRNAs (miRNAs) play a crucial regulatory function in the progression and advancement of heart disease following an MI. By consolidating the existing data on miRNAs, our aim is to gain a more comprehensive understanding of their role in the pathological progression of myocardial injury after MI and to identify potential crucial target pathways. Also included are the primary treatment modalities and their most recent developments. miRNAs have the ability to regulate both normal and pathological activity, including the key signaling pathways. As a result, they may exert medicinal benefits. This review presents a comprehensive analysis of the role of miRNAs in MI with a specific emphasis on their impact on the regeneration of cardiomyocytes and other forms of cell death, such as apoptosis, necrosis, and autophagy. Furthermore, the targets of pro- and anti-MI miRNAs are comparatively elucidated.

Hsa-miR-665 Is a Promising Biomarker in Cancer Prognosis

Biomarkers are biomolecules used to identify or predict the presence of a specific disease or condition. They play an important role in early diagnosis and may be crucial for treatment. MicroRNAs (miRNAs), a group of small non-coding RNAs, are more and more regarded as promising biomarkers for several reasons. Dysregulation of miRNAs has been linked with development of several diseases, including many different types of cancer, and abnormal levels can be present in early stages of tumor development. Because miRNAs are stable molecules secreted and freely circulating in blood and urine, they can be sampled with little or no invasion. Here, we present an overview of the current literature, focusing on the types of cancers for which dysregulation of miR-665 has been associated with disease progression, recurrence, and/or prognosis. It needs to be emphasized that the role of miR-665 sometimes seems ambiguous, in the sense that it can be upregulated in one cancer type and downregulated in another and can even change during the progression of the same cancer. Caution is thus needed before using miR-665 as a biomarker, and extrapolation between different cancer types is not advisable. Moreover, more detailed understanding of the different roles of miR-665 will help in determining its potential as a diagnostic and prognostic biomarker.

miRNAs orchestration of cardiovascular diseases - Particular emphasis on diagnosis, and progression

MicroRNAs (miRNAs; miRs) are small non-coding ribonucleic acids sequences vital in regulating gene expression. They are significant in many biological and pathological processes and are even detectable in various body fluids such as serum, plasma, and urine. Research has demonstrated that the irregularity of miRNA in multiplying cardiac cells is linked to developmental deformities in the heart's structure. It has also shown that miRNAs are crucial in diagnosing and progressing several cardiovascular diseases (CVDs). The review covers the function of miRNAs in the pathophysiology of CVD. Additionally, the review provides an overview of the potential role of miRNAs as disease-specific diagnostic and prognostic biomarkers for human CVD, as well as their biological implications in CVD.

Autophagy in intestinal fibrosis: relevance in inflammatory bowel disease

Chronic inflammation is often associated with fibrotic disorders in which an excessive deposition of extracellular matrix is a hallmark. Long-term fibrosis starts with tissue hypofunction and finally ends in organ failure. Intestinal fibrosis is not an exception, and it is a frequent complication of inflammatory bowel disease (IBD). Several studies have confirmed the link between deregulated autophagy and fibrosis and the presence of common prognostic markers; indeed, both up- and downregulation of autophagy are presumed to be implicated in the progression of fibrosis. A better knowledge of the role of autophagy in fibrosis may lead to it becoming a potential target of antifibrotic therapy. In this review we explore novel advances in the field that highlight the relevance of autophagy in fibrosis, and give special focus to fibrosis in IBD patients.

TLR5 Signaling in the Regulation of Intestinal Mucosal Immunity

Toll-like receptor 5 (TLR5) is a pattern recognition receptor that specifically recognizes flagellin and consequently plays a crucial role in the control of intestinal homeostasis by activating innate and adaptive immune responses. TLR5 overexpression, on the other hand, might disrupt the intestinal mucosal barrier, which serves as the first line of defense against harmful microbes. The intestine symbiotic bacteria, mucous layer, intestinal epithelial cells (IECs), adherens junctions (such as tight junctions and peripheral membrane proteins), the intestinal mucosal immune system, and cytokines make up the intestinal mucosal barrier. Impaired barrier function has been linked to intestinal illnesses such as inflammatory bowel disease (IBD). IBD is a persistent non-specific inflammatory illness of the digestive system with an unknown cause. It is now thought to be linked to infection, environment, genes, immune system, and the gut microbiota. The significance of immunological dysfunction in IBD has received more attention in recent years. The purpose of this paper is to explore TLR5's position in the intestinal mucosal barrier and its relevance to IBD.

Deep Dive Into MicroRNAs in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which includes ulcerative colitis and Crohn's disease, is thought to develop in genetically predisposed individuals as a consequence of complex interactions between dysregulated inflammatory stimuli, immunological responses, and environmental factors. The pathogenesis of IBD has yet to be fully understood. The global increase in the incidence of IBD suggests a gap in the current understanding of the disease. The development of a new diagnostic tool for inflammatory bowel disease that is both less invasive and more cost-effective would allow for better management of this condition. MicroRNAs (miRNAs) are a class of noncoding RNAs with important roles as posttranscriptional regulators of gene expression, which has led to new insights into understanding IBD. Using techniques such as microarrays and real-time polymerase chain reactions, researchers have investigated the patterns in which patients with Crohn's disease and ulcerative colitis show alterations in the expression of miRNA in tissue, blood, and feces. These miRNAs are found to be differentially expressed in IBD and implicated in its pathogenesis through alterations in autophagy, intestinal barrier, and immune homeostasis. In this review, we discuss the miRNA expression profiles associated with IBD in tissue, peripheral blood, and feces and provide an overview of the miRNA mechanisms involved in IBD.

miR-665 overexpression inhibits the apoptosis of luteal cells in small ruminants suppressing HPGDS

Evidence has shown that microRNA-665 (miR-665) is highly expressed in the mid-luteal phase compared with the early and end-luteal phase of the corpus luteum (CL) life cycle. However, whether miR-665 is a positive regulator of the life span of the CL is still unknown. The objective of this study is to explore the effect of miR-665 on the structural luteolysis in the ovarian CL. In this study, the targeting relationship between miR-665 and hematopoietic prostaglandin synthase (HPGDS) was firstly verified by dual luciferase reporter assay. Then, quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-665 and HPGDS in luteal cells. Following miR-665 overexpression, the apoptosis rate of the luteal cells was determined using flow cytometry; B-cell lymphoma-2 (BCL-2) and caspase-3 mRNA and protein were measured using qRT-PCR and Western blot (WB) analysis. Finally, the DP1 and CRTH2 receptors of PGD₂, a synthetic product of HPGDS, were localized using immunofluorescence. Results confirmed that HPGDS was a direct target gene of miR-665, and miR-665 expression was negatively correlated with HPGDS mRNA expression in luteal cells. Meanwhile, after miR-665 was overexpressed, the apoptotic rate of the luteal cells showed a significant decrease (P < 0.05) and this was accompanied by elevated expression levels of anti-apoptotic factor BCL-2 mRNA and protein and decreased expression levels of apoptotic factor caspase-3 mRNA and protein (P < 0.01). Moreover, the immune fluorescence staining results showed that the DP1 receptor was also significantly decreased (P < 0.05), but the CRTH2 receptor was significantly increased (P < 0.05) in luteal cells. Overall, these results indicate that miR-665 reduces the apoptosis of luteal cells via inhibiting caspase-3 expression and promoting BCL-2 expression, and the biological function of miR-665 may be attributed to its target gene HPGDS which regulates the balance of DP1 and CRTH2 receptors expression in luteal cells. As a consequence, this study suggests that miR-665 might be a positive regulator of the life span of the CL rather than destroy the integrity of CL in small ruminants.

MiRNA-Based Therapies for the Treatment of Inflammatory Bowel Disease: What Are We Still Missing?

Micro-RNAs (miRNAs) are noncoding RNAs usually 24-30 nucleotides long that play a central role in epigenetic mechanisms of inflammatory diseases and cancers. Recently, several studies have assessed the involvement of miRNAs in the pathogenesis of inflammatory bowel disease (IBD) and colitis-associated neoplasia. Particularly, it has been shown that many members of miRNAs family are involved in the pathways of inflammation and fibrogenesis of IBD; therefore, their use as inflammatory and fibrosis biomarkers has been postulated. In light of these results, the role of miRNAs in IBD therapy has been proposed and is currently under investigation with many in vitro and in vivo studies, murine models, and a phase 2a trial. The accumulating data have pushed miRNA-based therapy closer to clinical practice, although many open questions remain. With this systematic review, we discuss the current knowledge about the therapeutic effects of miRNAs mimicking and inhibition, and we explore the new potential targets of miRNA family for the treatment of inflammation and fibrosis in IBD.

The role of unfolded protein response-associated miRNAs in immunogenic cell death amplification: A literature review and bioinformatics analysis

Immunogenic cell death (ICD) is a type of cellular death that is elicited in response to the specific types of anti-cancer therapies and enhances the anti-tumor immune responses by the combination of antigenicity and adjuvanticity of dying tumor cells. There is a well-established interlink between endoplasmic reticulum stress (ERS) and ICD elicited by anti-cancer therapies. Most recent evidences support that unfolded protein response (UPR)-associated miRNAs can be key players in the ERS-induced ICD. Hence, in the present study, we conducted a literature review on the role of these miRNAs and associated molecular pathways that may regulate ICD. We first collected UPR-associated miRNAs that promote ERS-induced apoptosis and then focused on microRNAs (miRNAs) that promote ERS-induced apoptosis via PERK/eIF2α/ATF4/CHOP pathway activation, as the main core for ICD and release of damage-associated molecular patterns. To better identify PERK/eIF2α/ATF4/CHOP pathway-inducing miRNAs that can be used as potential therapeutic targets for improving ICD in cancer treatment, we did a comprehensive bioinformatics analysis and network construction. Our results showed that "pathways in cancer", "MAPK signaling pathway", "PI3K-Akt signaling pathway", and "Cellular senescence", which correlate with UPR components and ERS induction, were among the significant signaling pathways related to the target genes of these miRNAs. Furthermore, a protein-protein interaction (PPI) network was constructed, which revealed the involvement of the PPI-extracted hub genes in the regulation of proliferation and apoptosis. In conclusion, we propose that these types of miRNAs can be considered as the potential cancer therapy options for better induction of ICD in combination with other ICD inducers.

Exosomal miR-205-5p derived from periodontal ligament stem cells attenuates the inflammation of chronic periodontitis via targeting XBP1

INTRODUCTION

Chronic periodontitis (CP) is an inflammatory periodontal disease with high incidence and complex pathology. This research is aimed to investigate the function of exosomal miR-205-5p (Exo-miR-205-5p) in CP and the underlying molecular mechanisms.

METHOD

Exo-miR-205-5p was isolated from miR-205-5p mimics-transfected periodontal ligament stem cells (PDLSCs), and subsequently cocultured with lipopolysaccharide (LPS)-induced cells or injected into LPS-treated rats. The mRNA expression of inflammatory factors and Th17/Treg-related factors were measured by quantitative real-time PCR. The contents of inflammatory factors and the percentages of Th17/Treg cells were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Besides, the target relation between miR-205-5p and X-box binding protein 1 (XBP1) was explored.

RESULTS

MiR-205-5p was downregulated in LPS-induced PDLSCs and corresponding exosomes. Exo-miR-205-5p inhibited inflammatory cell infiltration, decreased the production of TNF-α, IL-1β, and IL-6, and decreased the percentage of Th17 cells in LPS-treated rats. In addition, XBP1 was a target of miR-205-5p. Overexpression of XBP1 weakened the effects of Exo-miR-205-5p on inhibiting inflammation and regulating Treg/Th17 balance in LPS-induced cells.

CONCLUSIONS

Exo-miR-205-5p derived from PDLSCs relieves the inflammation and balances the Th17/Treg cells in CP through targeting XBP1.

Identification of common molecular signatures of SARS-CoV-2 infection and its influence on acute kidney injury and chronic kidney disease

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the main cause of COVID-19, causing hundreds of millions of confirmed cases and more than 18.2 million deaths worldwide. Acute kidney injury (AKI) is a common complication of COVID-19 that leads to an increase in mortality, especially in intensive care unit (ICU) settings, and chronic kidney disease (CKD) is a high risk factor for COVID-19 and its related mortality. However, the underlying molecular mechanisms among AKI, CKD, and COVID-19 are unclear. Therefore, transcriptome analysis was performed to examine common pathways and molecular biomarkers for AKI, CKD, and COVID-19 in an attempt to understand the association of SARS-CoV-2 infection with AKI and CKD. Three RNA-seq datasets (GSE147507, GSE1563, and GSE66494) from the GEO database were used to detect differentially expressed genes (DEGs) for COVID-19 with AKI and CKD to search for shared pathways and candidate targets. A total of 17 common DEGs were confirmed, and their biological functions and signaling pathways were characterized by enrichment analysis. MAPK signaling, the structural pathway of interleukin 1 (IL-1), and the Toll-like receptor pathway appear to be involved in the occurrence of these diseases. Hub genes identified from the protein-protein interaction (PPI) network, including DUSP6, BHLHE40, RASGRP1, and TAB2, are potential therapeutic targets in COVID-19 with AKI and CKD. Common genes and pathways may play pathogenic roles in these three diseases mainly through the activation of immune inflammation. Networks of transcription factor (TF)-gene, miRNA-gene, and gene-disease interactions from the datasets were also constructed, and key gene regulators influencing the progression of these three diseases were further identified among the DEGs. Moreover, new drug targets were predicted based on these common DEGs, and molecular docking and molecular dynamics (MD) simulations were performed. Finally, a diagnostic model of COVID-19 was established based on these common DEGs. Taken together, the molecular and signaling pathways identified in this study may be related to the mechanisms by which SARS-CoV-2 infection affects renal function. These findings are significant for the effective treatment of COVID-19 in patients with kidney diseases.

Upregulation of miR-151-5p promotes the apoptosis of intestinal epithelial cells by targeting brain-derived neurotrophic factor in ulcerative colitis mice

Ulcerative colitis (UC) is the most prevalent form of chronic inflammatory bowel disease, the etiology of which is poorly understood. This study investigated the role of miR-151-5p on UC and explored the role of brain-derived neurotrophic factor (BDNF) in a UC mouse model and cell model. A UC mouse model was engineered by dextran sulfate sodium (DSS) induction. Primary mouse intestinal epithelial cells (IECs) were isolated. Colitis mice were intraperitoneally injected with miR-151-5p antagomir and antagomir negative control, and weight loss, disease activity index, and colon length of mice were measured. Colon tissues of mice were histologically analyzed. A UC cell model was constructed by treating MODE-K cells with DSS. miR-151-5p expression in the cell model was modulated by transfection. The exogenous BDNF effect on the UC cell model and intestinal cell apoptosis, viability and proliferation was detected by flow cytometry, CCK-8 and EdU experiment. The expression of miR-151-5p and apoptosis-related proteins was assessed through q-PCR and western blotting. miR-151-5p was upregulated in the colon tissues and primary IECs of colitis mice. miR-151-5p directly inhibited the expression of BNDF. miR-151-5p upregulation promoted apoptosis in UC MODE-K cells. miR-151-5p upregulation repressed the viability of UC MODE-K cells. Exogenous BNDF treatment reversed the effect of miR-151-5p on UC MODE-K cells. miR-151-5p knockdown improved UC symptoms in mice, including alleviating weight loss, reducing disease activity index and improving colon length and damaged colon tissues. miR-151-5p contributed to intestinal epithelial cells apoptosis in colitis mice via inhibiting BNDF expression.

MicroRNAs as Innovative Biomarkers for Inflammatory Bowel Disease and Prediction of Colorectal Cancer

Inflammatory bowel disease (IBD) includes ulcerative colitis (UC) and Crohn’s disease (CD). These are autoimmune diseases of the gastrointestinal tract with a chronic relapsing and remitting course. Due to complex interactions between multiple factors in the etiology of IBD, the discovery of new predictors of disease course and response to therapy, and the development of effective therapies is a significant challenge. The dysregulation of microRNAs (miRNAs), a class of conserved endogenous, small non-coding RNA molecules with a length of 18–25 nucleotides, that regulate gene expression by an RNA interference process, is implicated in the complex pathogenetic context of IBD. Both tissue-derived, circulating, and fecal microRNAs have been explored as promising biomarkers in the diagnosis and the prognosis of disease severity of IBD. In this review, we summarize the expressed miRNA profile in blood, mucosal tissue, and stool and highlight the role of miRNAs as biomarkers with potential diagnostic and therapeutic applications in ulcerative colitis and Crohn’s disease. Moreover, we discuss the new perspectives in developing a new screening model for the detection of colorectal cancer (CRC) based on fecal miRNAs.

miRNAs Can Affect Intestinal Epithelial Barrier in Inflammatory Bowel Disease

The most obvious pathological characterization of inflammatory bowel disease (IBD) is intestinal epithelium erosion and severe inflammation invasion. Micro-ribonucleic acids (miRNA or microRNA), single-stranded noncoding RNAs of ~22 nucleotides, have been considered as the potential therapeutic targets in the pathogenesis of IBD. Many previous studies have focused on the mechanisms that miRNAs use to regulate inflammation, immunity, and microorganisms in IBD. The review highlights in detail the findings of miRNAs in the intestinal epithelial barrier of IBD, and focuses on their gene targets, signaling pathways associated with IBD, and some potential therapies. It will be beneficial for the elucidation of the interaction between miRNAs and the intestinal epithelial barrier in IBD and provide a theoretical reference for preventing and treating IBD in the future.

Exploring the role of non-coding RNAs in autophagy

As a self-degradative mechanism, macroautophagy/autophagy has a role in the maintenance of energy homeostasis during critical periods in the development of cells. It also controls cellular damage through the eradication of damaged proteins and organelles. This process is accomplished by tens of ATG (autophagy-related) proteins. Recent studies have shown the involvement of non-coding RNAs in the regulation of autophagy. These transcripts mostly modulate the expression of ATG genes. Both long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been shown to modulate the autophagy mechanism. Levels of several lncRNAs and miRNAs are altered in this process. In the present review, we discuss the role of lncRNAs and miRNAs in the regulation of autophagy in diverse contexts such as cancer, deep vein thrombosis, spinal cord injury, diabetes and its complications, acute myocardial infarction, osteoarthritis, pre-eclampsia and epilepsy.Abbreviations: AMI: acute myocardial infarction; ATG: autophagy-related; lncRNA: long non-coding RNA; miRNA: microRNA.

Inhibition of microRNA-665 Alleviates Septic Acute Kidney Injury by Targeting Bcl-2

Sepsis can easily cause acute kidney injury (AKI) and seriously endanger human health. This article aims to investigate and study the role of microRNA-665 (miR-665) in septic AKI and the underlying molecular mechanism. Lipopolysaccharide (LPS) was used to construct cell and animal models of septic AKI. The expression of miR-665 in cells and kidney tissues was detected by quantitative reverse-transcription polymerase chain reaction (RT-PCR). The contents of inflammatory factors (TNF-α, IL-1β, and IL-6) in the cell supernatant were detected using commercial kits. Renal tissue damage was observed by hematoxylin-eosin (HE) staining. Kidney function was assessed by serum Cr, serum BUN, and urine NAG levels. The apoptosis of HK-2 cells was analyzed by flow cytometry and TUNEL staining. Luciferase activity assay was performed for the verification of the target of miR-665. The expression of miR-665 was increased in the cell model and animal model of septic AKI constructed by LPS. By transfecting miR-665 inhibitor in HK-2 cells and injecting miR-665 antagomir (antagomiR-665) through the tail vein of rats, the expression of miR-665 in HK-2 cells and rat kidneys was remarkably reduced. Silencing miR-665 dramatically inhibited the expression of inflammatory factors (TNF-α, IL-1β, and IL-6) in LPS-induced HK-2 cells and reduced LPS-induced apoptosis in HK-2 cells. At the same time, the levels of serum Cr, serum BUN, and urine NAG decreased markedly, and the damage of the kidney was also alleviated. Finally, luciferase reporter experiments demonstrated that miR-665 directly targets Bcl-2. We revealed that miR-665 expression was increased in septic AKI, and silencing miR-665 could inhibit LPS-induced inflammation and apoptosis of the kidney by targeting Bcl-2, thereby improving renal function.

Endoplasmic Reticulum Stress and miRNA Impairment in Aging and Age-Related Diseases

Aging is a physiological process defined by decreased cellular and tissue functions. Reduced capacity of protein degradation is one of the important hallmarks of aging that may lead to misfolded protein accumulation and progressive loss of function in organ systems. Recognition of unfolded/misfolded protein aggregates via endoplasmic reticulum (ER) stress sensors activates an adaptive mechanism, the unfolded protein response (UPR). The initial step of UPR is defined by chaperone enhancement, ribosomal translation suppression, and misfolded protein degradation, while prolonged ER stress triggers apoptosis. MicroRNAs (miRNAs) are non-coding RNAs affecting various signaling pathways through degradation or translational inhibition of targeted mRNAs. Therefore, UPR and miRNA impairment in aging and age-related diseases is implicated in various studies. This review will highlight the recent insights in ER stress–miRNAs alterations during aging and age-related diseases, including metabolic, cardiovascular, and neurodegenerative diseases and several cancers.

The functional role of miRNAs in inflammatory pathways associated with intestinal epithelial tight junction barrier regulation in IBD

Inflammatory bowel disease – Crohn's disease and ulcerative colitis – is an immune-mediated chronic disorder with still not fully elucidated complex mechanisms of pathogenesis and pathophysiology. Intestinal epithelial barrier (IEB) dysregulation is one of the major underlying mechanisms of inflammatory process induction in IBD. Proper IEB integrity is maintained to a large extent by intercellular tight junctions, the function of which can be modified by many molecules, including miRNAs. MiRNAs belong to noncoding and non-messenger RNAs, which can modulate gene expression by binding predicted mRNAs.

In this review, we summarize and discuss the potential role of miRNAs in the regulation of inflammatory signaling pathways affecting the function of the intestinal epithelial barrier in IBD, with particular emphasis on therapeutic potentials. The aim of the review is also to determine the further development directions of the studies on miRNA in the modulation of the intestinal epithelial barrier in IBD.

MicroRNA and Gut Microbiota: Tiny but Mighty-Novel Insights into Their Cross-talk in Inflammatory Bowel Disease Pathogenesis and Therapeutics

MicroRNAs [miRNAs], small non-coding RNAs, have recently been described as crucial contributors to intestinal homeostasis. They can interact with the gut microbiota in a reciprocal manner and deeply affect host health status, leading to several disorders when unbalanced. Inflammatory bowel disease [IBD] is a chronic inflammation of the gastrointestinal tract that co-occurs with alterations of the gut microbiota, and whose aetiology remains largely unclear. On one hand, host miRNA could be playing a relevant role in IBD pathophysiology by shaping the gut microbiota. The gut microbiome, on the other hand, may regulate the expression of host miRNAs, resulting in intestinal epithelial dysfunction, altered autophagy, and immune hyperactivation. Interestingly, it has been hypothesised that their reciprocal impact may be used for therapeutic goals. This review describes the latest research and suggests mechanisms through which miRNA and intestinal microbiota, as joint actors, may participate specifically in IBD pathophysiology. Furthermore, we discuss the diagnostic power and therapeutic potential resulting from their bidirectional communication after faecal transplantation, probiotics intake, or anti-miRNAs or miRNA mimics administration. The current literature is summarised in the present work in a comprehensive manner, hoping to provide a better understanding of the miRNA-microbiota cross-talk and to facilitate their application in IBD.

Recombinant protein Schistosoma japonicum-derived molecule attenuates dextran sulfate sodium-induced colitis by inhibiting miRNA-217-5p to alleviate apoptosis

BACKGROUND

Inflammatory bowel disease (IBD) affects millions of people worldwide and has emerged as a growing problem in industrialized nations. The lack of therapeutic targets has limited the treatment of IBD. Studies found that parasitic nematode infections can ameliorate clinical and experimental colitis. Our previous study found that rSj16, a 16-kDa secreted protein of Schistosoma japonicum produced by Escherichia coli, has protective effects on dextran sulfate sodium (DSS)-induced colitis in mice. Apoptosis is an important factor in the pathogenesis of colitis. However, it is not clear whether the effect of rSj16 on colitis is related to apoptosis.

AIM

To investigate whether the protective effects of rSj16 on colitis is related to apoptosis and its mechanism.

METHODS

In-vivo, colitis was induced by DSS. The severity of colitis was assessed. WB was used to detect the changes of apoptosis-related genes in colon tissues. Q-PCR was used to detect the changes of miRNA-217-5p and HNF1B. In-vitro, WB was used to detect the changes of apoptosis-related genes in intestinal epithelial cells. TUNNEL staining and flow cytometry were used to detect cell apoptosis.

RESULTS

rSj16 attenuates clinical activity in DSS-induced colitis mice. TUNNEL staining and WB results showed that apoptosis was increased in colon tissue after treatment with DSS, and the apoptosis of colon tissue was significantly reduced after treatment with rSj16. Compared with normal mice, the expression of miR-217-5p was increased in colon tissue of DSS-induced colitis mice. In addition, the miR-217-5p target gene hnf1b was decreased after administration of DSS. After treatment with rSj16, the expression of miR-217-5p was decreased and the expression of HNF1B was increased compared with the DSS-treated group. When Etoposide was used in combination with miR-217-5p mimic on MODE-K cells, the expression of cleaved-Caspase-3 and Bax was increased, and Bcl-2 was decreased compared with only Etoposide treatment, the expression of HNF1B was significantly reduced, suggesting that miR-217-5p acts as a pro-apoptotic in colon epithelial cells and down-regulates the target gene hnf1b. After rSj16 administration in MODE-K cells, miR-217-5p expression was significantly decreased, HNF1B expression was increased, and apoptosis was reduced.

CONCLUSION

The protective effects of rSj16 on colitis is related to apoptosis and miRNA-217-5p may be a further target for therapeutic intervention against IBD.

MiR-125-5p/IL-6R axis regulates macrophage inflammatory response and intestinal epithelial cell apoptosis in ulcerative colitis through JAK1/STAT3 and NF-κB pathway

This study explored the effects of miR-125-5p and interleukin-6 receptor (IL-6 R) on ulcerative colitis (UC) cell models and mouse models. The sera derived from UC patients and healthy subjects were collected for expression analysis. UC in vitro models and in vivo model were constructed and used. Expressions of miR-125-5p, IL-6 R, AK1/STAT3 and NF-κB pathways, and inflammatory factors, histopathology and apoptosis were determined by conducting a series of molecular experiments. The relationship between miR-125-5p and IL-6 R was analyzed by TargetScan7.2 and verified by dual-luciferase assay. The disease activity index (DAI) score, weight change, and colon length of the mice were recorded and analyzed. Decreased expression of miR-125-5p in the sera of UC patients was related to the increased expression of its target gene IL-6 R. In vitro, up-regulation of miR-125-5p decreased IL-6 R expression, contents of inflammatory factors in THP-1 cells and cell apoptosis of NCM460, and inhibited the activation of JAK1/STAT3 and NF-κB pathway. However, down-regulation of miR-125-5p produced the opposite effects to its up-regulation. IL-6 R overexpression partially reversed the effects of miR-125-5p up-regulation on UC cell models. In vivo, miR-125-5p overexpression significantly improved the severity of colitis, including DAI score, colon length, tissue damage, apoptosis, and inflammatory response, in the mice in the UC group. In addition, miR-125-5p up-regulation significantly reduced the expression of IL-6 R in the UC mice, and reduced the expression levels of JAK1, STAT3 and p65 phosphorylation. MiR-125-5p targeting IL-6 R regulates macrophage inflammatory response and intestinal epithelial cell apoptosis in ulcerative colitis through JAK1/STAT3 and NF-κB pathway.

DNA Damage-Regulated Autophagy Modulator 1 (DRAM1) Mediates Autophagy and Apoptosis of Intestinal Epithelial Cells in Inflammatory Bowel Disease

BACKGROUND AND AIMS

DNA damage-regulated autophagy modulator 1 (DRAM1) is required for induction of autophagy and apoptosis. However, the influence of DRAM1 on the pathogenesis of inflammatory bowel disease (IBD) has not been explored.

METHODS

DRAM1 expression was examined in the intestinal mucosa of patients with IBD and colons of colitis mice. We used a recombinant adeno-associated virus carrying small hairpain DRAM1 to knock down the DRAM1 gene to treat colitis in the mice. The effect of DRAM1 on autophagy and apoptosis of intestinal epithelial cells was explored. DRAM1-mediated interaction with the c-Jun N-terminal kinase (JNK) pathway was also examined.

RESULTS

DRAM1 expression in the intestinal mucosa of the IBD patients was higher than that in the control participates. DRAM1 expression in the inflammatory cells in patients with Crohn's disease (CD) was lower than that in patients with ulcerative colitis (UC). Additionally, DRAM1 expression was correlated with the Simple Endoscopic Score for CD and the Mayo endoscopic score for UC. Serum levels of DRAM1 in the IBD group were substantially higher than those in the normal group. The knockdown of DRAM1 could alleviate colitis symptoms in mice. In in vitro experiments, knocking down DRAM1 could reduce autophagy and apoptosis levels. Mechanistically, DRAM1 may participate in the regulation of these two processes by positively regulating JNK activation.

CONCLUSIONS

During intestinal inflammation, the upregulation of DRAM1 may promote the activation of JNK and further aggravate intestinal epithelium damage.

Inositol-Requiring Kinase 1 Regulates Apoptosis via Inducing Endoplasmic Reticulum Stress in Colitis Epithelial Cells

BACKGROUND

Endoplasmic reticulum stress (ERS) has been studied as critical factor during occurrence and development of ulcerative colitis (UC). However, the role of ERS in inflamed UC remains unclear.

AIMS

The purpose of this study was to analyze the role of inositol-requiring kinase 1 (IRE-1), a major regulator of ER, in regulating ERS and cell viability.

METHODS

In UC mucosa tissue, IRE-1, BiP, XBP-1s, CHOP caspase-12 and GADD34 mRNA were assayed by qRT-PCR. Then, human normal colon epithelial cell line (NCM-460) and colon fibroblast cell line (CCD-33Co) were cultured, and downregulated or upregulated IRE-1 expression. ERS was induced with 100 ng/mL of Interleukin 6 (IL-6). CCK8 assay was performed to analyze cell proliferation. Flow cytometry analysis was conducted to detect the apoptosis. Western blot assay was used to examine ERS markers.

RESULTS

IRE-1, BiP, XBP-1s, caspase-12 and CHOP mRNA were highly expressed in UC mucosa tissue, and the expression of GADD34 mRNA significantly decreased. These results show that ERS-induced unfolded protein response was enhanced in UC mucosa tissue. In cells, silencing the expression of IRE-1 could suppress cell proliferation and promote apoptosis through activating unfolded protein response, while the over-expression of IRE-1 had the opposite effect. IL-6 could induce ERS and cells apoptosis. Furthermore, we demonstrated that shRNA IRE-1 could enhance the inhibition of IL-6 on cells viability.

CONCLUSIONS

Inhibition of IRE-1 enhanced unfolded protein response and cells apoptosis and IL-6-induced ERS and suggested that IRE-1 might be a potential target of UC.

The role of miRNAs in the regulation of autophagy in autoimmune diseases

Autoimmune diseases (AD), which are classified as chronic injuries, are caused by a specific auto-reactive reaction. The etiology of most ADs is not well understood. Meanwhile, Autophagy is a protective response defining as a catabolic method by lysosomes tending to maintain homeostasis acts by recycling and discrediting cell compartments. Autophagy plays a crucial role in controlling immune homeostasis by eliminating intracellular pathogens and presenting antigens to immune cognition. MicroRNAs are commonly known as endogenous non-coding small RNAs, which span 18-25 nt and take part in the gene expression at the post-transcriptional level regulation. miRNAs play important roles in different processes like, cell differentiation, duplicating, and apoptosis. Moreover, miRNAs are the critical molecules for the regular function of the immune system by modulating immune tolerance mechanisms and autoimmunity. Recent findings support the role of dysregulated miRNAs in the pathogenesis of ADs and in the regulation of autophagy. In this review, we will focus on the role of the miRNAs in the regulation of autophagy and then will explain the role of dysregulated miRNAs in the initiation of the ADs by modulating autophagy.

Roles of microRNAs in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract that mainly affects young people. IBD is associated with various gastrointestinal symptoms, and thus, affects the quality of life of patients. Currently, the pathogenesis of IBD is poorly understood. Although intestinal bacteria and host immune response are thought to be major factors in its pathogenesis, a sufficient explanation of their role in its pathophysiologic mechanism has not been presented. MicroRNAs (miRNAs), which are small RNA molecules that regulate gene expression, have gained attention as they are known to participate in the molecular interactions of IBD. Recent studies have confirmed the important role of miRNAs in targeting certain molecules in signaling pathways that regulate the homeostasis of the intestinal barrier, inflammatory reactions, and autophagy of the intestinal epithelium. Several studies have identified the specific miRNAs associated with IBD from colon tissues or serum samples of IBD patients and have attempted to use them as useful diagnostic biomarkers. Furthermore, some studies have attempted to treat IBD through intracolonic administration of specific miRNAs in the form of nanoparticle. This review summarizes the latest findings on the role of miRNAs in the pathogenesis, diagnosis, and treatment of IBD.

microRNA in inflammatory bowel disease at a glance

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

MicroRNA and ER stress in cancer

The development of biological technologies in genomics, proteomics, and bioinformatics has led to the identification and characterization of the complete set of coding genes and their roles in various cellular pathways in cancer. Nevertheless, the cellular pathways have not been fully figured out like a jigsaw puzzle with missing pieces. The discovery of noncoding RNAs including microRNAs (miRNAs) has provided the missing pieces of the cellular pathways. Likewise, miRNAs have settled many questions of inexplicable patches in the endoplasmic reticulum (ER) stress pathways. The ER stress-caused pathways typified by the unfolded protein response (UPR) are pivotal processes for cellular homeostasis and survival, rectifying uncontrolled proteostasis and determining the cell fate. Although various factors and pathways have been studied and characterized, the understanding of the ER stress requires more wedges to fill the cracks of knowledge about the ER stress pathways. Moreover, the roles of the ER stress and UPR are still controversial in cancer despite their strong potential to promote cancer. The noncoding RNAs, in particular, miRNAs aid in a better understanding of the ER stress and its role in cancer. In this review, miRNAs that are the more-investigated subtype of noncoding RNAs are focused on the interpretation of the ER stress in cancer, following the introduction of miRNA and ER stress.

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.

MicroRNA Biomarkers in IBD-Differential Diagnosis and Prediction of Colitis-Associated Cancer

Inflammatory bowel disease (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC). These are chronic autoimmune diseases of unknown etiology affecting the gastrointestinal tract. The IBD population includes a heterogeneous group of patients with varying disease courses requiring personalized treatment protocols. The complexity of the disease often delays the diagnosis and the initiation of appropriate treatments. In a subset of patients, IBD leads to colitis-associated cancer (CAC). MicroRNAs are single-stranded regulatory noncoding RNAs of 18 to 22 nucleotides with putative roles in the pathogenesis of IBD and colorectal cancer. They have been explored as biomarkers and therapeutic targets. Both tissue-derived and circulating microRNAs have emerged as promising biomarkers in the differential diagnosis and in the prognosis of disease severity of IBD as well as predictive biomarkers in drug resistance. In addition, knowledge of the cellular localization of differentially expressed microRNAs is a prerequisite for deciphering the biological role of these important epigenetic regulators and the cellular localization may even contribute to an alternative repertoire of biomarkers. In this review, we discuss findings based on RT-qPCR, microarray profiling, next generation sequencing and in situ hybridization of microRNA biomarkers identified in the circulation and in tissue biopsies.

Pathophysiological role of Atg5 in human ulcerative colitis

BACKGROUND/AIMS

Ulcerative colitis (UC), along with Crohn's disease, is one of the main types of inflammatory bowel disease (IBD). On the other hand, deregulated autophagy is involved in many chronic diseases, including IBD. In this study, we aimed to investigate the role of Atg5 and microRNA-181a (miR-181a) in the pathophysiology of UC.

METHODS

Colon biopsy, stool, and blood samples of 6 men and 9 women were confirmed for UC. Also, 13 men and 17 women were selected as healthy control (HC). Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were used to measure the Atg-5 content of the colon biopsies. Besides, the serum and stool levels of Atg5 were measured using ELISA. Moreover, the total RNA of blood cells was extracted and evaluated for the expression of miR-181a.

RESULTS

We found 1.2 ng/mL versus 0.46 ng/mL, 0.34 ng/mL versus 0.24 ng/mL, and 0.082 ng/mL versus 0.062 ng/mL of Atg5 in stool, intestinal tissue, and serum of UC and HCs, respectively. There was no significant difference in the expression of miR-181a in the blood samples of UC and HCs. Immunohistochemistry showed high positivity without any significant difference between the 2 groups in the quantitative analysis.

CONCLUSIONS

The significant difference observed between the stool Atg5 content of the HCs and UC patients may provide new insight into using this protein as a diagnostic biomarker, however, considering the small size of our studied population further studies are needed.

IFN-γ promoted exosomes from mesenchymal stem cells to attenuate colitis via miR-125a and miR-125b

Bone marrow mesenchymal stem cells (MSCs) have demonstrated therapeutic effects for colitis through immunomodulation and anti-inflammation. However, whether MSC-derived exosomes possessed the similar function remains unclear. In present study, exosomes were isolated from control and IFN-γ-primed MSCs and was verified by transmission electron microscope (TEM) and immunofluorescence staining. Administration of exosomes to mice significantly improved the disease activity index and histological score of colitis, and decreased the ratio of Th17 cells with elevated Treg cells ratio in mice colitis model. Exosomes from IFN-γ-primed MSCs showed superior therapeutic effects to colitis. Exosomes treatment inhibited Th17 differentiation in vitro, and exosomes from IFN-γ-primed MSCs showed higher inhibition efficacy. Mechanistically, exosomes treatment significantly decreased the expression of Stat3 and p-Stat3 to inhibit Th17 cells differentiation. IFN-γ pretreatment increased the level of miR-125a and miR-125b of exosomes, which directly targeted on Stat3, to repress Th17 cell differentiation. Moreover, combination of miR-125a and miR-125b agmior infusion also showed therapeutic effects for colitis, accompanied by decreased Th17 cell ratio. Collectively, this study demonstrates that IFN-γ treatment promoted exosomes from MSCs to attenuate colitis through increasing the level of miR-125a and miR-125b, which binding on 3′-UTR of Stat3 to repress Th17 cell differentiation. This study provides a new approach of exocytosis on the treatment of colitis.

MiR-155 contributes to intestinal barrier dysfunction in DSS-induced mice colitis via targeting HIF-1α/TFF-3 axis

Intestinal barrier dysfunction is a hallmark of inflammatory bowel disease (IBD). MiR-155 is increased in colitis and downregulates expression of hypoxia-inducible factor 1α (HIF-1α). Here, we investigated the effects of miR-155 on intestinal barrier dysfunction in dextran sulfate sodium (DSS)-induced colitis. We found that miR-155 antagomir treatment relieved weight loss and intestinal damage in IBD mouse models (P < 0.05). Furthermore, electron microscopy and immunofluorescence imaging showed that miR-155 increased intestinal barrier dysfunction and downregulated the expression of tight junction proteins in DSS-induced colitis. FG-4497, which upregulates HIF-1α expression, elicited protective effects on the intestinal barrier in DSS-induced colitis. Dual luciferase reporter assays also confirmed that miR-155 downregulated expression of HIF-1α. Finally, we discovered that HIF-1α levels were elevated by miR-155 antagomir treatment (P < 0.05) and that TFF-3 expression correlated positively with HIF-1α expression. These results suggest that miR-155 contributes to DSS-induced colitis by promoting intestinal barrier dysfunction and inhibiting the HIF-1α/TFF-3 axis.

Baicalin alleviates TNBS-induced colitis by inhibiting PI3K/AKT pathway activation

Inflammatory bowel diseases (IBDs) are chronic immunological disorders of the intestinal tract characterized by persistent inflammation. Baicalin, a type of flavonoid, has exhibited a wide range of pharmacological activities, including immunomodulation and anti-inflammation. However, little is known about the therapeutic role of baicalin in IBD. The aim of the present study was to ascertain whether baicalin could be a therapeutic drug of IBD and investigate its specific mechanisms. In the present study, the results revealed that baicalin not only significantly alleviated TNBS-induced colitis by reducing the release of IL-6, TNF-α and IL-1β and increasing the level of IL-10, but promoted the expression of tight-junction proteins ZO-1 and β-catenin, which may have been achieved by blockage of the PI3K/AKT signaling pathway. In vitro, the results demonstrated that baicalin clearly inhibited the release of TNF-α, IL-6 and IL-1β and promoted the expression of IL-10 in LPS-induced HT-29 cells, and significantly decreased LPS-induced HT-29 cell apoptosis by blockage of the PI3K/AKT signaling pathway. In conclusion, the present research revealed for the first time that baicalin acted as a therapeutic drug in IBD by suppression of the PI3K/AKT signaling pathway.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

Long noncoding RNA SOX21-AS1 regulates the progression of triple-negative breast cancer through regulation of miR-520a-5p/ORMDL3 axis

Recently, long noncoding RNAs (lncRNAs) have been reported as a new kind of controllers about cancer processes in biology. In spite of the dysregulation of lncRNAs in various kinds of cancers, only a little of the information was effective on the expression configuration and inner effects of lncRNAs in triple-negative breast cancer (TNBC). This study valued the expression of lncRNA SOX21-AS1 and the biological role it played in TNBC. In our research, SOX21-AS1 had a high expression in TNBC cell lines. The functional experiments showed that knockdown of SOX21-AS1 obviously restrained cell proliferation, migration, invasion, and epithelial-mesenchymal transition process and promoted cell apoptosis. Mechanistically, SOX21-AS1 was found to bind with miR-520a-5p. Besides, ORMDL3 was identified as a downstream target of miR-520a-5p, and the suppressed ORMDL3 expression induced by silenced SOX21-AS1 could be restored by miR-520a-5p inhibition. Further, data from rescue assays revealed that SOX21-AS1 could regulate the malignancy of TNBC via miR-520a-5p/ORMDL3 axis. All in all, we identified that SOX21-AS1 regulated the cellular process of TNBC cells via antagonizing miR-520a-5p availability to upregulate ORMDL3 expression.

Mast cells-derived MiR-223 destroys intestinal barrier function by inhibition of CLDN8 expression in intestinal epithelial cells

Background

Mast cells (MCs) have been found to play a critical role during development of inflammatory bowel disease (IBD) that characterized by dysregulation of inflammation and impaired intestinal barrier function. However, the function of MCs in IBD remains to be fully elucidated.

Results

In our study, we used exosomes isolated from human mast cells-1 (HMCs-1) to culture with NCM460, HT-29 or CaCO2 of intestinal epithelial cells (IECs) to investigate the communication between MCs and IECs. We found that MCs-derived exosomes significantly increased intestinal epithelial permeability and destroyed intestinal barrier function, which is attributed to exosome-mediated functional miRNAs were transferred from HMCs-1 into IECs, leading to inhibit tight junction-related proteins expression, including tight junction proteins 1 (TJP1, ZO-1), Occludin (OCLN), Claudin 8 (CLDN8). Microarray and bioinformatic analysis have further revealed that a panel of miRNAs target different tight junction-related proteins. Interestingly, miR-223 is enriched in mast cell-derived exosome, which inhibit CLDN8 expression in IECs, while treatment with miR-223 inhibitor in HT-29 cells significantly reversed the inhibitory effect of HMCs-1-derived exosomes on CLDN 8 expression. Most importantly, enrichment of MCs accumulation in intestinal mucosa of patients with IBD compared with those healthy control.

Conclusions

These results indicated that enrichment of exosomal miR-223 from HMCs-1 inhibited CLDN8 expression, leading to destroy intestinal barrier function. These finding provided a novel insight of MCs as a new target for therapeutic treatment of IBD.

MicroRNA-219a-5p suppresses intestinal inflammation through inhibiting Th1/Th17-mediated immune responses in inflammatory bowel disease

MicroRNA (miR)-219a-5p has been implicated in the development of numerous progression of carcinoma and autoimmune diseases. However, whether miR-219a-5p is involved in the pathogenesis of inflammatory bowel disease (IBD) remains elusive. In this study, we demonstrated that miR-219a-5p expression was significantly decreased in the inflamed intestinal mucosa and peripheral blood (PB)-CD4⁺ T cells from patients with IBD. Proinflammatory cytokines (e.g., IL-6, IL-12, IL-23 and TNF-α) inhibited miR-219a-5p expression in CD4⁺ T cells in vitro. Lentivirus-mediated miR-219a-5p downregulation facilitated Th1/Th17 cell differentiation, whereas miR-219a-5p overexpression exerted an opposite effect. Luciferase assays confirmed that ETS variant 5 (ETV5) was a functional target of miR-219a-5p and ETV5 expression was significantly increased in the inflamed intestinal mucosa and PB-CD4⁺ T cells from IBD patients. ETV5 overexpression enhanced Th1/Th17 immune response through upregulating the phosphorylation of STAT3 and STAT4. Importantly, supplementation of miR-219a-5p ameliorated TNBS-induced intestinal mucosal inflammation, characterized by decreased IFN-γ⁺ CD4⁺ T cells and IL-17A⁺ CD4⁺ T cells infiltration in the colonic lamina propria. Our data thus reveal a novel mechanism whereby miR-219a-5p suppresses intestinal inflammation through inhibiting Th1/Th17-mediated immune responses. miR-219a-5p might be a target for the treatment of IBD.

Olmesartan alleviates bleomycin-mediated vascular smooth muscle cell senescence via the miR-665/SDC1 axis

Olmesartan (OMST) is a new angiotensin II receptor antagonist recently approved by the FDA to treat cardiovascular diseases. We investigated the molecular mechanisms by which OMST regulates vascular senescence. In the present study, bleomycin (BLM) was used to induce senescence in vascular smooth muscle cells (VSMCs); after which, the cells were treated with OMST. The effects of OMST on BLM-mediated cell senescence were evaluated using cell adhesion, NAD⁺/NADH, and Annevin V/PI double staining assays, as well as by immunofluorescence staining of γH2AX, Edu flow cytometry, and evaluations of senescence-associated β-gal activity. Differentially expressed microRNAs (DEMs) were identified by miRNA microarray assays, and subsequently validated by quantitative real time PCR. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the miR-665 promoter. The target genes of miR-665 were predicted and confirmed using luciferase reporter assays. We found that miR-665 was upregulated in VSMCs in response to BLM-induced cellular senescence. BSP studies revealed that CpG sites in the promoter region of the miR-665 gene underwent extensive demethylation during BLM-induced cellular senescence, and there was a concomitant up-regulation of miR-665 expression. SDC1 mRNA was identified as a direct target of miR-665. Either miR-665 overexpression or SDC1 knockdown significantly reversed the effects of OMST on BLM-induced VSMC senescence. Moreover, SDC1 overexpression partially reversed the changes that occurred in cells with BLM-induced senescence caused by miR-665 overexpression. Our findings suggest that the miR-665/SDC1 axis functions as a vital modulator of VSMC senescence, and may represent a novel biological target for treating atherosclerosis.

Nuclear miR-665 aggravates heart failure via suppressing phosphatase and tensin homolog transcription

Although numerous miRNAs have been discovered, their functions in the different subcellular organelles have remained obscure. In this study, we found that miR-665 was enriched in the nucleus of cardiomyocytes, and then investigated the underlying role of nuclear miR-665 in heart failure. RNA fluorescence in situ hybridization assays in human heart tissue sections and primary cardiomyocytes showed that miR-665 was localized in the nucleus of cardiomyocytes. Increased expression of nuclear miR-665 was observed not only in the cardiomyocytes isolated from the heart of mice treated in vivo by transverse aortic constriction (TAC), but also in phenylephrine (PE)-treated cultured cardiomyocytes in vitro. To further explore the role of miR-665 in heart failure, a type 9 recombinant adeno-associated virus (rAAV) system was employed to manipulate the expression of miR-665 in mice. Overexpression of miR-665 aggravated TAC-induced cardiac dysfunction, while down-expression of miR-665 showed opposite effects. Bioinformatic prediction and biological validation confirmed that the PTEN (phosphatase and tensin homolog) gene was one of the targets of miR-665 in the nucleus. Furthermore, restoring PTEN expression significantly eliminated the destructive effects of miR-665 over-expression in TAC-induced cardiac dysfunction. Our data showed that nuclear miR-665 aggravates heart failure via inhibiting PTEN expression, which provided a therapeutic approach for heart failure.

miR-665 promotes the progression of gastric adenocarcinoma via elevating FAK activation through targeting SOCS3 and is negatively regulated by lncRNA MEG3

Studies have found that miR-665 acted as a tumor suppressor or an oncogene in different malignancies. miR-665 expression was elevated in gastric adenocarcinoma tissues; however, its role and mechanism in this disease are not fully clarified. The expression of miR-665 and its target gene was detected in human gastric adenocarcinoma tissues and cells. Moreover, we analyzed the effects of miR-665 on the proliferation, migration, and epithelial-mesenchymal transition (EMT) of gastric adenocarcinoma cells as well as tumor growth in vivo. The mechanisms of miR-665 in gastric adenocarcinoma were investigated by using molecular biology techniques. We found miR-665 was upregulated and suppressor of cytokine signaling 3 (SOCS3) was downregulated in gastric adenocarcinoma tissues and cells. Elevated miR-665 was positively correlated with tumor size, lymph node metastasis, invasion depth, TNM stage, and poor differentiation in gastric adenocarcinoma patients. Overexpression of miR-665 promoted, whereas knockdown of miR-665 suppressed the proliferation, migration, and EMT of gastric adenocarcinoma cells. Furthermore, we demonstrated that miR-665 functioned through targeting SOCS3, followed by activation of the FAK/Src signaling pathway in gastric adenocarcinoma cells. miR-665 antagomir inhibited tumor growth as well as the activation of the FAK/Src pathway but increased SOCS3 expression in nude mice. In addition, miR-665 expression was negatively regulated by long noncoding RNA maternally expressed gene 3 (MEG3). In conclusion, miR-665 acted as an oncogene in gastric adenocarcinoma by inhibiting SOCS3 followed by activation of the FAK/Src pathway and it was negatively modulated by MEG3. miR-665 may be a promising therapeutic target for the treatment of gastric adenocarcinoma.