Comparison of MicroRNA Expression in Tears of Normal Subjects and Sjögren Syndrome Patients

MiR-34a promotes mitochondrial pathway of apoptosis in human salivary gland epithelial cells by activating NF-κB signaling

To investigate the potential molecular mechanism of miR-34a in Sjögren's syndrome (SS). Transmission electron microscopy was used to observe the salivary gland tissues of mild and severe SS patients. SS mouse model was constructed and injected with miR-34a antagonist. HSGE cells were transfected with miR-34a mimic. Starbase predicted miR-34a binding sites and validated them with dual-luciferase reporter assays. Immunohistochemistry, HE staining, CCK-8, TUNEL assay, flow cytometry, immunofluorescence and Western Blot were used to investigate the effects of miR-34a on NF-κB signaling and mitochondrial pathway of apoptosis in HSGE cells. Severe SS patients showed obvious mitochondrial damage and apoptosis in salivary glands. MiR-34a was overexpressed and NF-κB signaling is activated in salivary glands of severe SS patients. Inhibition of miR-34a alleviated salivary gland injury in SS mice, as well as inhibited the activation of NF-κB signaling and mitochondrial pathway of apoptosis. In conclusion, miR-34a promoted NF-κB signaling by targeting IκBα, thereby causing mitochondrial pathway apoptosis and aggravating SS-induced salivary gland damage.

Single nucleotide polymorphisms of GEMIN3 modify the risk of primary Sjögren's syndrome in female patients

BACKGROUND

MicroRNA (miRNA)-processing machinery may modify the risk of primary Sjögren's syndrome (pSS) by altering miRNA expression profiles. Inflammatory cytokines and reactive oxygen species (ROS) are also involved in pSS; however, the role of altered miRNAs expression in its pathogenesis is still unclear. We aimed to evaluate the relationship between single-nucleotide polymorphisms (SNPs) in miRNA processing machinery genes, including XPO5 (rs11077), RAN (rs14035), Dicer (rs3742330), TNRC6B (rs9623117), GEMIN3 (rs197412), and GEMIN4 (rs2740348), and the risk of pSS in female patients. The potential associations of cytokines and ROS with pSS-susceptible SNPs were also evaluated.

METHODS

The SNPs confirmed by polymerase chain reaction ligase detection reaction were genotyped in 74 female patients with pSS and 77 controls. The relationship was analyzed by Student's t-test, Wilcoxon rank-sum test, chi-square test, Pearson's correlation test, and binary logistic regression analysis.

RESULTS

For rs197412 of the GEMIN3 gene, the genotype TT carrier was associated with a 2.172-fold increased risk for pSS when compared with that of CT+CC carrier (odds ratio: 2.172, 95% CI, 1.133-4.166, p=0.019). Simultaneously, the pSS-susceptible TT carriers were associated with increased interferon-γ (IFN-γ) (P<0.001) and tumor necrosis factor-α (TNF-α) (P=0.003) levels when compared with that of CT+CC genotype carriers in female patients with pSS. The subsequent analysis also showed a weak positive correlation between IFN-γ and TNF-α levels (r=0.271, P=0.019).

CONCLUSION

The predictors of GEMIN3 SNPs might modify pSS development in females by mediating the expression of miRNAs and therefore regulate the levels of IFN-γ and TNF-α.

WGCNA and machine learning analysis identifi ed SAMD9 and IFIT3 as primary Sjögren's Syndrome key genes

Background

Current treatments for primary Sjögren's Syndrome (pSS) are with limited effect, partially due to the heterogeneity and uncleared mechanism.

Methods

We got GSE40568 (Japan) and GSE40611 (USA), and analyzed them with WGCNA to find key Differentially expressed genes (DEGs) between pSS and healthy salivary glands (SG). Key pSS genes (KPGs) were further selected through 3 machine-learning methods. The expression of KPGs was validated via two other GEO datasets (GSE127952 and GSE154926). Infiltrated immune cells, ceRNA network, and potential compounds were explored.

Results

Our study identified 376 DEGs from the pSS patients, with 186 genes located in the "plum2" module, showing the strongest correlation with clinical characteristics. SAMD9 and IFIT3 emerged as KPGs with excellent diagnostic potential. SAMD9 demonstrated close association with immune cell infiltration. We constructed a lncRNA-miRNA-mRNA network comprising 2 KPGs, 12 miRNAs, 124 lncRNAs, and potential therapeutic targets.

Conclusion

In the investigation of pSS public datasets, our study revealed two potential critical mediators in the pathological process of pSS salivary glands, namely SAMD9 and IFIT3. Furthermore, we put forth a hypothesis regarding the ceRNA network and made predictions regarding potential therapeutic drugs targeting these two genes.

MicroRNA expression profiling in tears and blood as predictive biomarkers for anti-VEGF treatment response in wet age-related macular degeneration

PURPOSE

This study aimed to investigate the potential of microRNAs (miRNAs) in tears, blood, and aqueous humor as biomarkers for predicting treatment response in wet age-related macular degeneration (AMD) patients undergoing anti-vascular endothelial growth factor (anti-VEGF) therapy.

METHODS

In a single-center prospective cohort study, treatment-naïve wet AMD patients and age-matched controls were enrolled. Clinical data and miRNA levels (miR-199a-3p, miR-365-3p, miR-200b-3p, miR-195-5p, miR-335-5p, and miR-185-5p) in tears, blood, and aqueous humor were collected. Treatment response was categorized into responders and non-responders based on visual acuity and central subfield thickness. MiRNA levels were quantified using reverse-transcription PCR. Statistical analyses were performed, including ROC analysis, to evaluate predictive accuracy.

RESULTS

Dysregulated miRNA profiles were observed in wet AMD tears and blood compared to controls. Specifically, miR-199a-3p, miR-195-5p, and miR-185-5p were upregulated, while miR-200b-3p was downregulated in tears. All six miRNAs were elevated in wet AMD blood samples. Notably, responders showed higher tear expression of miR-195-5p and miR-185-5p. Combining these miRNAs yielded the highest predictive power (AUC = 0.878, p = 0.006) for anti-VEGF responders.

CONCLUSIONS

Dysregulated miRNA profiles in tears and blood suggest their potential as biomarkers for wet AMD. MiR-195-5p and miR-185-5p in tears demonstrate predictive value for anti-VEGF treatment responders. This study underscores the non-invasive prediction potential of miRNA tear analysis in wet AMD treatment responses.

Identification and verification of inflammatory biomarkers for primary Sjögren's syndrome

INTRODUCTION

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by inflammatory infiltration, and dysfunction of the salivary and lacrimal glands. This research aimed to explore the disease pathogenesis and improve the diagnosis and treatment of pSS by mining inflammation-associated biomarkers.

METHODS

Five pSS-related datasets were retrieved from the Gene Expression Omnibus (GEO) database. Inflammation-associated biomarkers were determined by the least absolute shrinkage and selection operator (LASSO) and support vector machines recursive feature elimination (SVM-RFE). Single sample gene set enrichment analysis (ssGSEA) was implemented to profile the infiltration levels of immune cells. Real-time quantitative PCR (RT-qPCR) verified the expression of biomarkers in clinical samples.

RESULTS

Four genes (LY6E, EIF2AK2, IL15, and CXCL10) were screened as inflammation-associated biomarkers in pSS, the predictive performance of which were determined among three pSS-related datasets (AUC > 0.7). Functional enrichment results suggested that the biomarkers were involved in immune and inflammation-related pathways. Immune infiltration analysis revealed that biomarkers were notably connected with type 2 T helper cells, regulatory T cells which were significantly expressed between pSS and control. TESTOSTERONE and CYCLOSPORINE were predicted to take effect by targeting CXCL10 and IL15 in pSS, respectively.

CONCLUSION

Four inflammation-associated biomarkers (LY6E, EIF2AK2, IL15, and CXCL10) were explored, and the underlying regulatory mechanisms and targeted drugs associated with these biomarkers were preliminarily investigated according to a series of bioinformatics methods based on the online datasets of pSS, which provided a reference for understanding the pathogenesis of pSS. Key Points • Inflammation-associated biomarkers (LY6E, EIF2AK2, IL15, and CXCL10) were firstly identified in Sjögren's syndrome based on LASSO and SVM-RFE analyses. • CXCL10, EIF2AK2 and LY6E were prominently positively correlated with immature B cells, while IL15 were significantly negatively correlated with memory B cells in Sjögren's syndrome. • LY6E, EIF2AK2, IL15, and CXCL10 were significantly more highly expressed in clinical Sjögren's syndrome samples compared to healthy control samples, which was consistent with the analysis results of the GEO database. •LY6E, EIF2AK2, IL15, and CXCL10 might be used as the biomarkers for the treatment and diagnosis of Sjögren's syndrome.

Association of endometriosis with Sjögren's syndrome: Genetic insights (Review)

Patients with a history of endometriosis have an increased risk of developing various autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis and celiac disease. There is a potential association between endometriosis and an increased susceptibility for Sjögren's syndrome (SS). SS is a common chronic, inflammatory, systemic, autoimmune, multifactorial disease of complex pathology, with genetic, epigenetic and environmental factors contributing to the development of this condition. It occurs in 0.5‑1% of the population, is characterized by the presence of ocular dryness, lymphocytic infiltrations and contributes to neurological, gastrointestinal, vascular and dermatological manifestations. Endometriosis is an inflammatory, estrogen‑dependent, multifactorial, heterogeneous gynecological disease, affecting ≤10% of reproductive‑age women. It is characterized by the occurrence of endometrial tissue outside the uterine cavity, mainly in the pelvic cavity, and is associated with pelvic pain, dysmenorrhea, deep dyspareunia and either subfertility or infertility. It is still unclear whether SS appears as a secondary response to endometriosis, or it is developed due to any potential shared mechanisms of these conditions. The aim of the present review was to explore further the biological basis only of the co‑occurrence of these disorders but not their association at clinical basis, focusing on the analysis of the partially shared genetic background between endometriosis and SS, and the clarification of the possible similarities in the underlying pathogenetic mechanisms and the relevant molecular pathways.

Advances in Sjögren's Syndrome Dry Eye Diagnostics: Biomarkers and Biomolecules beyond Clinical Symptoms

Sjögren's syndrome dry eye (SSDE) is a subset of Sjögren's syndrome marked by dry eye symptoms that is distinct from non-Sjögren's syndrome dry eye (NSSDE). As SSDE can lead to severe complications, its early detection is imperative. However, the differentiation between SSDE and NSSDE remains challenging due to overlapping clinical manifestations. This review endeavors to give a concise overview of the classification, pathophysiology, clinical features and presentation, ocular and systemic complications, clinical diagnosis, and management of SSDE. Despite advancements, limitations in current diagnostic methods underscore the need for novel diagnostic modalities. Thus, the current review examines various diagnostic biomarkers utilized for SSDE identification, encompassing serum, salivary, and tear analyses. Recent advancements in proteomic research and exosomal biomarkers offer promising diagnostic potential. Through a comprehensive literature review spanning from 2016 to 2023, we highlight molecular insights and advanced diagnostic modalities that have the potential to enhance our understanding and diagnosis of SSDE.

Profiling miRNAs in tear extracellular vesicles: a pilot study with implications for diagnosis of ocular diseases

PURPOSE

To estimate the roles of extracellular vesicles (EVs) in tears and to determine whether their profiles are associated with the type of ocular disease.

STUDY DESIGN

Cross-sectional study.

METHODS

Tear EVs were extracted from 14 healthy participants and from 21 patients with retinal diseases (age-related macular degeneration [AMD] or diabetic macular edema [DME]). The surface marker expression of tear EVs was examined, and microRNAs (miRNAs) were extracted and profiled by use of real-time PCR array. The stability of the expression of the miRNAs was determined, and their functions were assessed by network analyses. Classification accuracy was evaluated by use of a random forest classifier and k-fold cross-validation.

RESULTS

The miRNAs that were highly expressed in tear EVs were miR-323-3p, miR-548a-3p, and miR-516a-5p. The most stably expressed miRNAs independent of diseases were miR-520h and miR-146b-3p. The primary networks of the highly stably expressed endogenous miRNAs were annotated as regulation of organismal injury and abnormalities. The highly expressed miRNAs for severe retinal disease were miR-151-5p for AMD and miR-422a for DME, suggesting potential roles of tear EVs in liquid biopsy. Nine miRNAs (miR-25, miR-30d, miR-125b, miR-132, miR-150, miR-184, miR-342-3p, miR-378, and miR-518b) were identified as distinguishing individuals with AMD from healthy individuals with a classification accuracy of 91.9%.

CONCLUSIONS

The finding that tear EVs contain characteristic miRNA species indicates that they may help in maintaining homeostasis and serve as a potential tool for disease diagnosis.

Integrated analysis of microRNA expression in tears of Kazakh patients with climatic droplet keratopathy in Xinjiang, China

Climatic droplet keratopathy (CDK) is a corneal diseases, which is characterized by increased oil-like deposits on the anterior elastic lamina and anterior stromal layer. Severe CDK can even cause blindness, with no specific available treatment. Besides. CDK is poorly understood in terms of its pathogenic mechanisms. Thus, to determine potential biomarkers for CDK, we analyzed the microRNA expression profile in tear samples from CDK patients and investigated their putative roles in the pathogenesis of CDK. Herein, miRNA sequencing and following bioinformatics analysis was performed to explore the roles of their target genes in CDK. A total of 67 differentially expressed miRNAs were identified, of which 25 were upregulated and 42 were downregulated. qPCR verification showed that among the up- and down-regulated miRNAs, expression of five and six, respectively, was most significantly different.The target genes of the differentially expressed miRNAs are involved in the FoxO signaling pathway, tumor necrosis factor (TNF) signaling pathway, and steroid hormone biosynthesis. Protein-protein interaction network analyses identified 20 hub genes, including PTEN, GSK3B, and SMAD3. In conclusion, the panel of differentially expressed miRNAs identified may have potential utility as early diagnostic biomarkers for CDK. Moreover, the TNF signaling pathway is a new potential target in CDK for the development of treatments.

Extracellular vesicles as a new horizon in the diagnosis and treatment of inflammatory eye diseases: A narrative review of the literature

Extracellular vesicles include exosomes, microvesicles, and apoptotic bodies. Their cargos contain a diverse variety of lipids, proteins, and nucleic acids that are involved in both normal physiology and pathology of the ocular system. Thus, studying extracellular vesicles may lead to a more comprehensive understanding of the pathogenesis, diagnosis, and even potential treatments for various diseases. The roles of extracellular vesicles in inflammatory eye disorders have been widely investigated in recent years. The term “inflammatory eye diseases” refers to a variety of eye conditions such as inflammation-related diseases, degenerative conditions with remarkable inflammatory components, neuropathy, and tumors. This study presents an overview of extracellular vesicles’ and exosomes’ pathogenic, diagnostic, and therapeutic values in inflammatory eye diseases, as well as existing and potential challenges.

Tear Film MicroRNAs as Potential Biomarkers: A Review

MicroRNAs are non-coding RNAs that serve as regulatory molecules in a variety of pathways such as inflammation, metabolism, homeostasis, cell machinery, and development. With the progression of sequencing methods and modern bioinformatics tools, novel roles of microRNAs in regulatory mechanisms and pathophysiological states continue to expand. Advances in detection methods have further enabled larger adoption of studies utilizing minimal sample volumes, allowing the analysis of microRNAs in low-volume biofluids, such as the aqueous humor and tear fluid. The reported abundance of extracellular microRNAs in these biofluids has prompted studies to explore their biomarker potential. This review compiles the current literature reporting microRNAs in human tear fluid and their association with ocular diseases including dry eye disease, Sjögren's syndrome, keratitis, vernal keratoconjunctivitis, glaucoma, diabetic macular edema, and diabetic retinopathy, as well as non-ocular diseases, including Alzheimer's and breast cancer. We also summarize the known roles of these microRNAs and shed light on the future progression of this field.

Key methodological challenges in detecting circulating miRNAs in different biofluids

The technological advancement in diagnostic techniques has immensely improved the capability of predicting disease progression. Yet, there is a great interest in developing newer biomarkers that can enhance disease risk prediction thereby minimising the associated morbidity and mortality. Circulating miRNAs, a non-coding RNA molecule, are critical regulators in the pathophysiology of various complex multifactorial diseases. In recent years, circulating miRNAs have been enormously studied and are considered as an emerging biomarker due to their easy accessibility, stability, and detection by sequence-specific amplification methods. However, there is a distinct lack of consensus regarding the preanalytical factors such as preferred sample selection, methodological aspects, etc that may independently or together influence the detection of circulating miRNAs resulting in erroneous expression profiles. Therefore, the present review makes an attempt to highlight the various pre-analytical and analytical factors that can potentially influence the circulating miRNA levels. Literature on circulating miRNA's stability, processing and quantitation in different biofluids along with the effect of various controllable and uncontrollable factors influencing circulating miRNA expression have been summarised in the current review.

Tear Film miRNAs and Their Association With Human Dry Eye Disease

PURPOSE

miRNAs can regulate inflammatory pathways. The purpose of this work was to determine if inflammatory-related tear film miRNAs are associated with extracellular vesicles (EVs) in human non-Sjögren's Syndrome dry eye disease (DED) participants.

METHODS

Five DED and 5 non-DED human participants were recruited. Tears samples were collected by washing the ocular surface of both eyes with phosphate buffered saline, pooling samples from the right and left eyes, and purifying EVs from the samples with a polyethylene glycol (PEG) 8000 precipitation procedure. Samples were directly analyzed via ELISA or transmission electron microscopy (TEM), or RNA was isolated first from the EVs and evaluated with RNA-Seq.

RESULTS

EVs were identified in the tear film of both groups using TEM and ELISA. Following EV purification and RNA isolation, RNA-Seq determined that there were 126 EV miRNAs differentially expressed between the two groups when comparing their RNA cargoes. Ingenuity Pathways Analysis found 9 upregulated miRNAs that were associated with inflammation (miR-127-5p, miR-1273h-3p, miR-1288-5p, miR-130b-5p, miR-139-3p, miR-1910-5p, miR-203b-5p, miR-22-5p, and miR-4632-3p; all p < 0.049; fold regulation range = 1.43-1.67).

CONCLUSION

This study determined that EVs are present in the tear film and that tear EVs contain miRNAs that may be associated with DED inflammatory pathways.

Updates in diagnostics, treatments, and correlations between oral and ocular manifestations of Sjogren's syndrome

Sjogren's syndrome (SS) is characterized as an autoimmune disorder targeting secretory glands, including the lacrimal and salivary glands, causing dry eye and dry mouth predominantly in women over the age of 40. In this review, we summarize recent advancements in SS diagnostics, treatments, and our understanding of correlations between oral and ocular manifestations of SS. Google Scholar and PubMed databases were utilized to search peer-reviewed papers since 2016 on SS diagnosis, treatment, and correlations between oral and ocular manifestations. For diagnostics, we discuss the updated SS classification criteria by the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR), new biomarkers, and compare studies of current diagnostic methods with alternative technologies. For treatments, we discuss topical, systemic, and surgical treatment developments in the management of oral and ocular symptoms of SS as there is still no cure for the disorder. Finally, we report studies that directly suggest correlations between the ocular surface disease and oral disease in SS, as well as shared abnormalities in the microbiome and cytokine expression that may be correlated. We conclude by stating limitations to our review as well as paths moving forward. Elucidating correlations between oral and ocular manifestations may be the key to furthering our understanding of SS pathogenesis as well as defining new standards for diagnosis and treatment.

Potential utility of miRNAs for liquid biopsy in breast cancer

Breast cancer (BC) remains the most prevalent malignancy due to its incidence rate, recurrence, and metastasis in women. Conventional strategies of cancer detection– mammography and tissue biopsy lack the capacity to detect the complete cancer genomic landscape. Besides, they often give false- positive or negative results. The presence of this and other disadvantages such as invasiveness, high-cost, and side effects necessitates developing new strategies to overcome the BC burden. Liquid biopsy (LB) has been brought to the fore owing to its early detection, screening, prognosis, simplicity of the technique, and efficient monitoring. Remarkably, microRNAs (miRNAs)– gene expression regulators seem to play a major role as biomarkers detected in the samples of LB. Particularly, miR-21 and miR-155 among other possible candidates seem to serve as favorable biomarkers in the diagnosis and prognosis of BC. Hence, this review will assess the potential utility of miRNAs as biomarkers and will highlight certain promising candidates for the LB approach in the diagnosis and management of BC that may optimize the patient outcome.

Clinical Tear Fluid Proteomics—A Novel Tool in Glaucoma Research

Tear fluid forms the outermost layer of the ocular surface and its characteristics and composition have been connected to various ocular surface diseases. As tear proteomics enables the non-invasive investigation of protein levels in the tear fluid, it has become an increasingly popular approach in ocular surface and systemic disease studies. Glaucoma, which is a set of multifactorial diseases affecting mainly the optic nerve and retinal ganglion cells, has also been studied using tear proteomics. In this condition, the complete set of pathophysiological changes occurring in the eye is not yet fully understood, and biomarkers for early diagnosis and accurate treatment selection are needed. More in-depth analyses of glaucoma tear proteomics have started to emerge only more recently with the implementation of LC-MS/MS and other modern technologies. The aim of this review was to examine the published data of the tear protein changes occurring during glaucoma, its topical treatment, and surgical interventions.

Diminished miR-374c-5p negatively regulates IL (interleukin)-6 in unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) is commonly observed, and seriously affects women's reproductive health. Excessive interleukin-6 (IL-6) production has been shown to frequently occur and relate to URSA pathogenesis. In this study, the miRNA expression profile in peripheral blood mononuclear cells (PBMCs) from URSA patients and normal pregnant (NP) women was assessed by miRNA microarray and real-time quantitative reverse-transcription polymerase chain reaction (qPCR). MiRNA target prediction tools and luciferase reporter assay were used to detect direct binding between miRNAs and IL6. Functional study of administering anti-IL-6 neutralizing antibody and miR-374c-5p mimics to an URSA animal model was performed to evaluate embryo resorption rates. In the results, compared with NP women, the expression of IL-6 increased markedly in PBMCs and decidual tissues at both mRNA and protein levels, while miR-374c-5p expression decreased significantly. Prediction software and luciferase reporter assay showed that miR-374c-5p binds with IL6 3'UTR via the complementary bases. Transfection of miR-374c-5p mimics into an in vitro HeLa cell line significantly downregulated the expression of IL-6, while transfection of the miR-374c-5p inhibitor induced an opposite result. In the URSA mouse model, miR-374c-5p overexpression reduced the embryo resorption rate significantly, accompanied with decreased expression of IL-6 in the decidua. To sum up, downregulated miR-374c-5p was involved in the pathogenesis of URSA by enhancing IL-6 expression. Modulation of miR-374c-5p expression may be used to regulate IL-6 production for the treatment of URSA.

MicroRNA Profiling of the Tears of Children With Vernal Keratoconjunctivitis

Vernal Keratoconjunctivitis (VKC) is a chronic conjunctival inflammatory condition that typically affects children. Extracellular microRNAs (miRNAs) are small noncoding RNA molecules, the expression of which is reported to regulate cellular processes implicated in several eye diseases. The aim of this preliminary study is to identify the miRNA expression profile in the tears of children with VKC vis-à-vis controls, and to statistically evaluate these miRNAs as potential diagnostic biomarkers of VKC. The study involved a VKC group and a control group. Tear specimens were collected using Schirmer’s strips. RNA was isolated using miRNeasy Micro kit and quantification was performed using an Agilent Bioanalyzer RNA 6000 Nano kit and Small RNA kit. miRNA profiling was performed using the Agilent microarray technique. A total of 51 miRNAs (48 upregulated and three downregulated) were differentially expressed in the tears of children with VKC and controls. The three most significantly upregulated miRNAs were hsa-miR-1229-5p, hsa-miR-6821-5p, and hsa-miR-6800-5p, and the three most significantly downregulated miRNAs were hsa-miR-7975, hsa-miR-7977, and hsa-miR-1260a. All the upregulated miRNAs are potential diagnostic biomarkers of VKC pending validation due to their larger discriminatory area under the curve (AUC) values. miRNA target prediction analysis revealed multiple overlapping genes that are known to play a role in conjunctival inflammation. We identified a set of differentially expressed miRNAs in the tears of children with VKC that may play a role in VKC pathogenesis. This study serves as the platform study for future miRNA studies that will provide a deeper understanding of the pathophysiology of VKC.

Tears as the Next Diagnostic Biofluid: A Comparative Study between Ocular Fluid and Blood

The need to easily isolate small molecular weight proteins and genomic fragments has prompted a search for an alternative biofluid to blood that has traversed sweat, urine, saliva, and even breath. In this study, both the genomic and proteomic profiles of tears and blood are evaluated to determine the similarity and differences between the two biofluids. Both fluids were tested utilizing microarray panels for identifying proteins as well as isolation of microRNA for sequencing. As anticipated, most (118) of the proteins detected in plasma were also detected in the tear samples, with tear samples also showing 34 unique proteins that were not found in the plasma. Over 400 microRNAs were isolated in both samples with 250 microRNA fragments commonly expressed in both tears and blood. This preliminary analysis, along with simplicity of collection and processing, lends credence to further investigate tears as an alternative biofluid to blood.

Tear miRNAs Identified in a Murine Model of Sjögren’s Syndrome as Potential Diagnostic Biomarkers and Indicators of Disease Mechanism

Objective

The tear miRNAome of the male NOD mouse, a model of ocular symptoms of Sjögren’s syndrome (SS), was analyzed to identify unique miRNAs.

Methods

Male NOD mice, aged 12-14 weeks, were used to identify tear miRNAs associated with development of autoimmune dacryoadenitis. Age- and sex-matched male BALB/c mice served as healthy controls while age-matched female NOD mice that do not develop the autoimmune dacryoadenitis characteristic of SS were used as additional controls. Total RNA was isolated from stimulated tears pooled from 5 mice per sample and tear miRNAs were sequenced and analyzed. Putative miRNA hits were validated in additional mouse cohorts as well as in tears of SS patients versus patients with another form of dry eye disease, meibomian gland disease (MGD) using qRT-PCR. The pathways influenced by the validated hits were identified using Ingenuity Pathway Analysis.

Results

In comparison to tears from both healthy (male BALB/c) and additional control (female NOD) mice, initial analy1sis identified 7 upregulated and 7 downregulated miRNAs in male NOD mouse tears. Of these, 8 were validated by RT-qPCR in tears from additional mouse cohorts. miRNAs previously implicated in SS pathology included mmu-miR-146a/b-5p, which were significantly downregulated, as well as mmu-miR-150-5p and mmu-miR-181a-5p, which were upregulated in male NOD mouse tears. All other validated hits including the upregulated miR-181b-5p and mmu-miR-203-3p, as well as the downregulated mmu-miR-322-5p and mmu-miR-503-5p, represent novel putative indicators of autoimmune dacryoadenitis in SS. When compared to tears from patients with MGD, miRNAs hsa-miR-203a-3p, hsa-miR-181a-5p and hsa-miR-181b-5p were also significantly increased in tears of SS patients.

Conclusions

A panel of differentially expressed miRNAs were identified in tears of male NOD mice, with some preliminary validation in SS patients, including some never previously linked to SS. These may have potential utility as indicators of ocular symptoms of SS; evaluation of the pathways influenced by these dysregulated miRNAs may also provide further insights into SS pathogenesis.

MicroRNAs in Various Body Fluids and its importance in Forensic Medicine

MicroRNAs (miRNAs) are a class of noncoding RNAs which regulate gene expression. miRNAs have tissue-specific expression and are also present in various extracellular body fluids, including blood, tears, semen, vaginal fluid and urine. Additionally, expression of miRNAs in body fluids is linked to various pathological diseases, including cancer and neurodegenerative diseases. Examination of body fluids is important in forensic medicine as they serve as a valuable form of evidence. Due to its stability, miRNA offers an advantage for body fluid identification, which can be detected even after several months or from compromised samples. Identification of unique miRNA profiles for different body fluids enable the identification of these body fluid. Furthermore, miRNAs profiling can be used to estimate post-mortem interval. Various biochemical and molecular methods have been used for identification of miRNAs have shown promising results. We discuss different miRNAs as specific biomarkers and their clinical importance regarding different pathological conditions, as well as their medico-legal importance.

Tear miRNA expression analysis reveals miR-203 as a potential regulator of corneal epithelial cells

Background

microRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression. They are found within cells and in body fluids. Extracellular miRNAs have been shown to associate with the surrounding tissues. Therefore, we predicted that miRNAs in tears may contribute to regulate corneal epithelial cell function. However, information on the miRNA expression profile of tears is limited and the specific functions of tear miRNAs for corneal epithelial cells are still unknown. To study the role of tear miRNAs, we determined which miRNAs are highly expressed in tears and examined the involvement of miRNAs in corneal epithelial cell viability.

Methods

miRNAs extracted from monkey tears and sera were subjected to microarray analysis. miRNAs of which expression levels were higher in tears than in sera were selected, and their expression levels were quantified by quantitative polymerase chain reaction (qPCR). To examine miRNA function, mimics and inhibitors of miRNAs were transfected into human corneal epithelial (HCE-T) cells and incubated for 24 or 48 h. After transfection of miRNA mimics and inhibitors, the viability of HCE-T cells was measured using the water soluble tetrazolium salt (WST) assay, and microarray analysis and qPCR were performed using total RNA extracted from HCE-T cells. siRNAs of the candidate targets for miR-203 were transfected into HCE-T cells and the WST assay was performed. To determine a direct target gene for miR-203, a dual luciferase reporter assay was performed in HCE-T cells using a luciferase reporter plasmid containing 3′-UTR of human IGFBP5.

Results

Microarray and qPCR analyses showed that miR-184 and miR-203 were expressed significantly more highly in tears than in sera (165,542.8- and 567.8-fold, respectively, p < 0.05). Of these two miRNAs, transfection of a miR-203 mimic significantly reduced the viability of HCE-T cells (p < 0.05), while a miR-203 inhibitor significantly increased this viability (p < 0.05). miR-203 mimic downregulated insulin-like growth factor-binding protein 5 (IGFBP5) and nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1), while miR-203 inhibitor upregulated these two genes. Transfection of IGFBP5-siRNA decreased the viability of HCE-T cells. miR-203 mimic significantly diminished the luciferase reporter activity.

Conclusions

In this study, we identified miRNAs that are highly expressed in tears, and the inhibition of miR-203 increases the viability of corneal epithelial cells. Our results suggest that miR-203 contributes to regulating the homeostasis of corneal epithelial cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02141-9.

Piperlongumine inhibits the progression of osteosarcoma by downregulating the SOCS3/JAK2/STAT3 pathway via miR-30d-5p

AIMS

The present study evaluated the functions of Piperlongumine (PL) in osteosarcoma (OS) cell growth and metastasis both in vitro and in vivo.

MAIN METHODS

MTT assay was conducted to test the cytotoxic effects of PL on the human osteoblasts line HFOB1.19 and the human normal chondrocyte line C28/I2T. FITC-Annexin V and propidium iodide (PI) were used to examine cell apoptosis. The migration, invasion and relative epithelial-mesenchymal transition were examined by Transwell assay and Western blotting. Reverse transcription-quantitative PCR (RT-qPCR) was performed to analyze the cytokine signaling 3 (SOCS3) mRNA expression. TargetScan database was used to predict the target of SOCS3. The binding association between miR-30d-5p and SOCS3 in U2OS and MG63 cells was evaluated by the dual-luciferase reporter assay. A xenograft model was constructed to evaluate the effect of PL on OS cell growth in vivo.

KEY FINDINGS

The results revealed that PL inhibited the growth, migration, invasion, epithelial-mesenchymal transition, and promoted the apoptosis of OS cells dose-dependently. In addition, PL upregulated the protein levels of suppressor of SOCS3, while it inactivated the JAK2/STAT3 pathway, which was accompanied by a decreased level of microRNA (miR)-30d-5p. Furthermore, SOCS3was confirmed as a novel target of miR-30d-5p. Overexpression of miR-30d-5p not only led to decreased expression of SOCS3, but also dampened the antitumor effect of PL on OS.

SIGNIFICANCE

The present data demonstrated that PL inhibited the progression of OS via downregulation of the SOCS3-mediated JAK2/STAT3 pathway by inhibiting miR-30d-5p.

Emerging Role of microRNAs and Long Non-Coding RNAs in Sjögren's Syndrome

Sjögren’s Syndrome (SS) is a chronic autoimmune inflammatory disease. It is considered a multifactorial pathology, in which underlying genetic predisposition, epigenetic mechanisms and environmental factors contribute to development. The epigenetic regulations represent a link between genetic predisposition and environmental factors. Recent studies suggested a regulatory role for non-coding RNAs in critical biological and disease processes. Among non-coding RNAs, microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) play a critical role in the post-transcriptional mRNA expression, forming a complex network of gene expression regulation. This review aims to give an overview of the latest studies that have investigated the role of miRNAs and lncRNAs in the SS. We included papers that investigated the expression of non-coding RNAs on different tissues, in particular on peripheral blood mononuclear cells and salivary glands. However, regarding the involvement of non-coding RNAs genetic variability in SS susceptibility very few data are available. Further research could help to elucidate underlying pathogenic processes of SS and provide new opportunities for the development of targeted therapies.

Exosomes in the pathogenesis and treatment of ocular diseases

Exosomes have diverse functions and rich content and are involved in intercellular communication, immune regulation, viral infection, tissue regeneration, and the occurrence, development and metastasis of tumours. Notably, various stem cell-derived exosomes are expected to become new therapeutic approaches for inflammatory diseases and tumours and have good clinical application prospects. However, few studies have examined exosomes in ophthalmic diseases. Therefore, based on the functions of exosomes, this paper summarizes progress in the possible use of exosomes as treatment for specific ophthalmic diseases, aiming to determine the pathogenesis of exosomes to achieve more effective clinical diagnosis and treatment of these diseases.

Identification of diagnostic genes and vital microRNAs involved in rheumatoid arthritis: based on data mining and experimental verification

Background

The pathogenesis of rheumatoid arthritis (RA) is complex. This study aimed to identify diagnostic biomarkers and transcriptional regulators that underlie RA based on bioinformatics analysis and experimental verification.

Material and Methods

We applied weighted gene co-expression network analysis (WGCNA) to analyze dataset GSE55457 and obtained the key module most relevant to the RA phenotype. We then conducted gene function annotation, gene set enrichment analysis (GSEA) and immunocytes quantitative analysis (CIBERSORT). Moreover, the intersection of differentially expressed genes (DEGs) and genes within the key module were entered into the STRING database to construct an interaction network and to mine hub genes. We predicted microRNA (miRNA) using a web-based tool (miRDB). Finally, hub genes and vital miRNAs were validated with independent GEO datasets, RT-qPCR and Western blot.

Results

A total of 367 DEGs were characterized by differential expression analysis. The WGCNA method divided genes into 14 modules, and we focused on the turquoise module containing 845 genes. Gene function annotation and GSEA suggested that immune response and inflammatory signaling pathways are the molecular mechanisms behind RA. Nine hub genes were screened from the network and seven vital regulators were obtained using miRNA prediction. CIBERSORT analysis identified five cell types enriched in RA samples, which were closely related to the expression of hub genes. Through ROC curve and RT-qPCR validation, we confirmed five genes that were specific for RA, including CCL25, CXCL9, CXCL10, CXCL11, and CXCL13. Moreover, we selected a representative gene (CXCL10) for Western blot validation. Vital miRNAs verification showed that only the differences in has-miR-573 and has-miR-34a were statistically significant.

Conclusion

Our study reveals diagnostic genes and vital microRNAs highly related to RA, which could help improve our understanding of the molecular mechanisms underlying the disorder and provide theoretical support for the future exploration of innovative therapeutic approaches.

microRNA exchange via extracellular vesicles in cancer

Cells utilize different means of inter-cellular communication to function properly. Here, we review the crosstalk between cancer cells and their surrounding environment through microRNA (miRNA)-containing extracellular vesicles (EVs). The current findings suggest that the export of miRNAs and uptake of miRNA-containing EVs might be an active process. As post-transcriptional regulators of gene expression, cancer-derived miRNAs that are taken up by normal cells can change the translational profile of the recipient cell towards a transformed proteome. Stromal cells can also deliver miRNAs via EVs to cancer cells to support tumour growth and cancer progression. Therefore, gaining a better understanding of EV-mediated inter-cellular communication in the tumour microenvironment might lead to the development of novel diagnostic and therapeutic strategies.

Discovery of microRNA expression profiles involved in regulating TGF-2 expression in the tears of dry eye patients

BACKGROUND

To date, the difference in microRNA expression profiles in tears of dry eye patients and healthy people has not been reported. In current study, we evaluated the significance of microRNAs and transforming growth factor beta2 (TGF-β2) in distinguishing dry eye.

METHODS

A total of 138 patients with dry eye from October 2017 to October 2018 were selected. During the same period, 138 healthy persons were collected. All patients were followed up for 12 months through outpatient, telephone or medical records and the time of corneal injury was recorded.

RESULTS

Compared with healthy people, TGF-β2 concentrations in dry eye patients were significantly decreased (P < 0.05). Array analysis, predictive software and dual-luciferase reporter assays showed that miR-450b-5p, miR-1283 and miR-3671 can target TGF-β2 expression. Tear miR-450b-5p, miR-1283 and miR-3671 concentrations were significantly higher in dry eye patients than healthy people. A logistic regression model combining miR-450b-5p, miR-1283, miR-3671 and TGF-β2 was performed. This model presented a high discriminating value (AUC: 0.907, 0.876-0.939, P < 0.001) than any single indicator, and the sensitivity and specificity were 77.7% and 92.7%, respectively. Compared with the low miR-450b-5p, low miR-1283, low miR-3671 and high TGF-β2 groups, the high miR-450b-5p, high miR-1283, high miR-3671 and low TGF-β2 groups had a significantly higher probability of corneal injury (TGF-β2: χ² = 5.762, P = 0.016; miR-450b-5p: χ² = 13.267, P < 0.001; miR-1283: χ² = 19.431, P < 0.001; miR-3671: χ² = 8.131, P = 0.004).

CONCLUSION

Current model combining tear miR-450b-5p, miR-1283, miR-3671 and TGF-β2 had important values in the identification of dry eye and was of great value in evaluating the risk of corneal injury.

Aberrantly expressed lncRNAs and mRNAs after botulinum toxin type A inhibiting salivary secretion

OBJECTIVE

In this study, we sought to determine the expression profiles of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) and construct functional networks to analyze their potential roles following botulinum toxin type A (BTXA)-mediated inhibition of salivary secretion.

METHODS

The submandibular gland of rats in the BTXA and control groups was injected with BTXA and saline, respectively. Microarray analysis was used to identify the differentially expressed lncRNAs and mRNAs. Gene ontology and pathway analysis were performed to examine the biological functions. Functional networks, including lncRNA-mRNA co-expression and competing endogenous RNA (ceRNA) networks, were constructed to reveal the interaction between the coding and non-coding genes.

RESULTS

Microarray analysis revealed that 254 lncRNAs and 631 mRNAs were differentially expressed between the BTXA and control groups. Bioinformatic analysis revealed that most of the mRNAs were closely related to transmembrane transporter activity. lncRNA-mRNA co-expression and ceRNA networks were constructed, and several critical mRNA-lncRNA axes and key microRNAs related to salivary secretion were identified.

CONCLUSIONS

Our study identified differentially expressed lncRNAs and mRNAs through microarray analysis and explored the interactions between the coding and non-coding genes through bioinformatic analysis. These findings provide new insights into the mechanism of BTXA-mediated inhibition of salivary secretion.

Epigenetic Regulations of AhR in the Aspect of Immunomodulation

Environmental factors contribute to autoimmune disease manifestation, and as regarded today, AhR has become an important factor in studies of immunomodulation. Besides immunological aspects, AhR also plays a role in pharmacological, toxicological and many other physiological processes such as adaptive metabolism. In recent years, epigenetic mechanisms have provided new insight into gene regulation and reveal a new contribution to autoimmune disease pathogenesis. DNA methylation, histone modifications, chromatin alterations, microRNA and consequently non-genetic changes in phenotypes connect with environmental factors. Increasing data reveals AhR cross-roads with the most significant in immunology pathways. Although study on epigenetic modulations in autoimmune diseases is still not well understood, therefore future research will help us understand their pathophysiology and help to find new therapeutic strategies. Present literature review sheds the light on the common ground between remodeling chromatin compounds and autoimmune antibodies used in diagnostics. In the proposed review we summarize recent findings that describe epigenetic factors which regulate AhR activity and impact diverse immunological responses and pathological changes.

MicroRNAs and Autoimmune-Mediated Eye Diseases

MicroRNAs (miRNAs) are evolutionarily conserved short non-coding RNAs that act at post-transcriptional regulation of gene expression by destroying target messenger RNA or inhibiting its translation. Recently, miRNAs have been identified as important regulators in autoimmunity. Aberrant expression and function of miRNAs can lead to dysfunction of immune system and mediate autoimmune disorders. Here, we summarize the roles of miRNAs that have been implicated in three representative ocular autoimmune disorders, including autoimmune uveitis, Grave's ophthalmopathy, and Sjögren's syndrome dry eye, and discuss the potential of miRNAs as biomarkers and therapeutic targets for the diagnosis and treatment of these diseases.

MicroRNA Biomarkers for Infectious Diseases: From Basic Research to Biosensing

In the pursuit of improved diagnostic tests for infectious diseases, several classes of molecules have been scrutinized as prospective biomarkers. Small (18–22 nucleotide), non-coding RNA transcripts called microRNAs (miRNAs) have emerged as promising candidates with extensive diagnostic potential, due to their role in numerous diseases, previously established methods for quantitation and their stability within biofluids. Despite efforts to identify, characterize and apply miRNA signatures as diagnostic markers in a range of non-infectious diseases, their application in infectious disease has advanced relatively slowly. Here, we outline the benefits that miRNA biomarkers offer to the diagnosis, management, and treatment of infectious diseases. Investigation of these novel biomarkers could advance the use of personalized medicine in infectious disease treatment, which raises important considerations for validating their use as diagnostic or prognostic markers. Finally, we discuss new and emerging miRNA detection platforms, with a focus on rapid, point-of-care testing, to evaluate the benefits and obstacles of miRNA biomarkers for infectious disease.

MicroRNA expression profile of Lacrimal Glands in rabbit autoimmune dacryoadenitis model

Purpose: To identify the differential expression of microRNAs (miRs) and the related gene networks and signal pathways in lacrimal glands (LGs) of rabbit autoimmune dacryoadenitis. Methods: Autoimmune dacryoadenitis in rabbits was induced by transferring activated peripheral blood lymphocytes (PBLs). The LGs of normal and model group rabbits were collected for small RNA sequencing. The most differentially expressed miRs were validated by quantitative real time-polymerase chain reaction (qRT-PCR). Further, bioinformatics analysis including target gene prediction, Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. Results: A total of 15 miRs were differentially expressed in the LGs of rabbit autoimmune dacryoadenitis relative to normal controls. GO and KEGG analysis revealed that most target genes of these dysregulated miRs were implicated in MAPK signaling pathway. Conclusion: Our results showed for the first time the differentially expressed miRs and the related pathways involved in the pathogenesis of rabbit autoimmune dacryoadenitis. These results may contribute to elucidating molecular pathogenesis of Sjögren's syndrome (SS) dry eye.