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

Comprehensive analysis of differentially expressed genes in toll-like receptor signalling pathway: Insights into new-onset microscopic polyangiitis

OBJECTIVE

We aimed to elucidate the potential contributions of the toll-like receptor (TLR) signalling pathway and identify promising candidates for new-onset microscopic polyangiitis (MPA) using integrated bioinformatics analysis.

METHODS

A PCR array was used to determine the expression profiles of TLR signalling-related genes in CD4+T lymphocytes of individuals with new-onset MPA and healthy controls. Four genes were selected for validation through real-time quantitative polymerase chain reaction (RT-qPCR). Followed by functional enrichment and pathway analysis, we identified the hub genes with cytoHubba. The differentially expressed miRNAs of the target genes were subsequently predicted and visualized via Cytoscape. Finally, these candidates were validated and evaluated at the expression level and for diagnostic value in public databases.

RESULTS

Nineteen differentially expressed genes were screened, and the levels of the validated genes detected using RT‒qPCR were consistent with the findings obtained through the PCR array. The significantly enriched signalling pathways involved were TLR signalling pathway, IL-17 signalling pathway, and NF-κB signalling pathway. Nine hub genes and nine key miRNAs were identified. Furthermore, analysis of three distinct gene expression datasets validated several key genes (TLR4, MYD88, IRF1, CXCL10, CXCL8, and CSF2), showing significant differences between groups and strong diagnostic value, especially TLR4, MYD88, and IRF1. Interestingly, in contrast to the validation results, our results showed that CXCL10 and CXCL8 expression levels were markedly lower, but CSF2 was highly expressed in patients with MPA compared to controls.

CONCLUSION

Aberrant expression of TLRs may occur in CD4+ T lymphocytes of patients with new-onset MPA, offering insights into the pathogenesis as well as potential biomarkers and novel therapeutic targets.

Serum and Tear Autoantibodies from NOD and NOR Mice as Potential Diagnostic Indicators of Local and Systemic Inflammation in Sjögren's Disease

Background

Sjögren's Disease (SjD) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands (LG). The LG produces the protein-rich aqueous component of tears, and SjD-associated autoimmune dacryoadenitis (AD) may thus alter tear autoantibody composition.

Methods

The presence of tertiary lymphoid structures (TLS) in LG from two murine models of SjD-associated AD, male NOD and male NOR mice, were evaluated using immunofluorescence. IgG and IgA reactivity in serum and tears from these models were probed in three studies against a panel of 80-120 autoantigens using autoantibody microarrays relative to serum and tears from healthy male BALB/c mice. Data were analyzed by R package Limma.

Results

Analysis of immunofluorescence in LG sections from both SjD models showed TLS. Only one autoantibody was significantly elevated in tears and serum in both SjD models across all studies. Three autoantibodies were significantly elevated in serum but not in tears in both SjD models across all studies. Conversely, six IgG and thirteen IgA autoantibodies (6 sharing the same autoantigen) were significantly elevated in tears but not serum in both SjD models.

Conclusion

NOD and NOR mice with SjD-associated AD have distinct autoantibody profiles in tears and serum. Tear IgA isotype autoantibodies showed a greater diversity than tear IgG autoantibodies. TLS observed in LG are a likely source of the tear autoantibodies.

Study on the mechanism of miRNAs on liver injury in the condition of Protoscocephalus alveolarus transhepatic portal vein infection

OBJECTIVE

To explore the role of miRNA in liver damage caused by Echinococcus multilocularis infection.

METHODS

Six female C57BL mice were randomly divided into two groups, the control group and the infection group. Mice in the control group were injected with 100 μL PBS through the hepatic portal vein, and mice in the infection group were infected with E. multilocularis via the hepatic portal vein to establish a mouse model of infection. Small RNA sequencing was performed for detecting the expression of miRNAs in the liver of mice infected with 2000 E. multilocularis after 3 months of infection, screen out miRNAs related to liver damage, and verify by RT-PCR.

RESULTS

Seventy-one differentially expressed miRNAs were found in the liver in comparison with control, and a total of 36 mouse miRNAs with |FC| >0.585 were screened out, respectively. In addition, Targetscan (V5.0) and miRanda (v3.3a) software were used to predict differential miRNAs target genes and functional enrichment of target genes. Functional annotation showed that "cytokine-cytokine interaction," "positive regulation of cytokine production," "inflammatory response," and "leukocyte activation" were enriched in the liver of E. multilocularis-infected mice. Moreover, the pathways "human cytomegalovirus infection," "cysteine and methionine metabolism," "Notch signaling pathway," and "ferroptosis" were involved in liver disease. Furthermore, four miRNAs (mmu-miR-30e-3p, mmu-miR-203-3p, mmu-miR-125b-5p, and mmu-miR-30c-2-3p) related to liver injury were screened and verified.

CONCLUSION

This study revealed that the expression profiling of miRNAs in the livers was changed after E. multilocularis infection, and improved our understanding of the transcriptomic landscape of hepatic echinococcosis in mice.

Role of microRNAs in Immune Regulation with Translational and Clinical Applications

MicroRNAs (miRNAs) are 19-23 nucleotide long, evolutionarily conserved noncoding RNA molecules that regulate gene expression at the post-transcriptional level. In this review, involvement of miRNAs is summarized in the differentiation and function of immune cells, in anti-infective immune responses, immunodeficiencies and autoimmune diseases. Roles of miRNAs in anticancer immunity and in the transplantation of solid organs and hematopoietic stem cells are also discussed. Major focus is put on the translational clinical applications of miRNAs, including the establishment of noninvasive biomarkers for differential diagnosis and prediction of prognosis. Patient selection and response prediction to biological therapy is one of the most promising fields of application. Replacement or inhibition of miRNAs has enormous therapeutic potential, with constantly expanding possibilities. Although important challenges still await solutions, evaluation of miRNA fingerprints may contribute to an increasingly personalized management of immune dysregulation with a remarkable reduction in toxicity and treatment side effects. More detailed knowledge of the molecular effects of physical exercise and nutrition on the immune system may facilitate self-tailored lifestyle recommendations and advances in prevention.

Advances in mesenchymal stem cell-derived extracellular vesicles therapy for Sjogren's syndrome-related dry eye disease

Sjogren's syndrome (SS) is a chronic autoimmune disorder that affects exocrine glands, particularly lacrimal glands, leading to dry eye disease (DED). DED is a common ocular surface disease that affects millions of people worldwide, causing discomfort, visual impairment, and even blindness in severe cases. However, there is no definitive cure for DED, and existing treatments primarily relieve symptoms. Consequently, there is an urgent need for innovative therapeutic strategies based on the pathophysiology of DED. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic tool for various autoimmune disorders, including SS-related DED (SS-DED). A particularly intriguing facet of MSCs is their ability to produce extracellular vesicles (EVs), which contain various bioactive components such as proteins, lipids, and nucleic acids. These molecules play a key role in facilitating communication between cells and modulating a wide range of biological processes. Importantly, MSC-derived EVs (MSC-EVs) have therapeutic properties similar to those of their parent cells, including immunomodulatory, anti-inflammatory, and regenerative properties. In addition, MSC-EVs offer several notable advantages over intact MSCs, including lower immunogenicity, reduced risk of tumorigenicity, and greater convenience in terms of storage and transport. In this review, we elucidate the underlying mechanisms of SS-DED and discuss the relevant mechanisms and targets of MSC-EVs in treating SS-DED. In addition, we comprehensively review the broader landscape of EV application in autoimmune and corneal diseases. This review focuses on the efficacy of MSC-EVs in treating SS-DED, a field of study that holds considerable appeal due to its multifaceted regulation of immune responses and regenerative functions.

Lactobacillus acidophilus and propionate attenuate Sjögren's syndrome by modulating the STIM1-STING signaling pathway

BACKGROUND

Sjögren's syndrome (SS) is an autoimmune disease characterized by inflammation of the exocrine gland. An imbalance of gut microbiota has been linked to SS. However, the molecular mechanism is unclear. We investigated the effects of Lactobacillus acidophilus (L. acidophilus) and propionate on the development and progression of SS in mouse model.

METHODS

We compared the gut microbiomes of young and old mice. We administered L. acidophilus and propionate up to 24 weeks. The saliva flow rate and the histopathology of the salivary glands were investigated, and the effects of propionate on the STIM1-STING signaling pathway were evaluated in vitro.

RESULTS

Lactobacillaceae and Lactobacillus were decreased in aged mice. SS symptoms were ameliorated by L. acidophilus. The abundance of propionate-producing bacterial was increased by L. acidophilus. Propionate ameliorated the development and progression of SS by inhibiting the STIM1-STING signaling pathway.

CONCLUSIONS

The findings suggest that Lactobacillus acidophilus and propionate have therapeutic potential for SS. Video Abstract.

Plasma miR-150-5p as a Biomarker for Chronic Obstructive Pulmonary Disease

Purpose

To investigate the potential of plasma microRNA-150-5p (miR-150-5p) as a biomarker for chronic obstructive pulmonary disease (COPD) and its relationship with clinical indicators such as pulmonary function.

Patients and Methods

Fifty-nine patients with COPD and twenty-six healthy control individuals were recruited in the Second People's Hospital of Hefei from September 2021 to September 2022. The plasma expression level of miR-150-5p was measured by quantitative real-time polymerase chain reaction.

Results

The miR-150-5p level in the COPD group was significantly lower than that in the control group, and the relative expression was lower in patients with severe airflow limitation than those with mild limitation. Plasma miR-150-5p levels were positively correlated with pulmonary function indicators and negatively correlated with the white blood cell count and C-reactive protein level. The receiver operating characteristic curve suggested that plasma miR-150-5p had predictive value for COPD (area under curve = 0.819, sensitivity 64.4%, specificity 92.3%).

Conclusion

MiR-150-5p can be useful for the diagnosis and disease assessment of COPD, and has value as a biomarker for COPD.

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.