Characterization of microRNA expression profiling in peripheral blood lymphocytes in rats with experimental autoimmune uveitis

Steroidal nanoformulations for the treatment of uveitis: potential, promises and future perspectives

BACKGROUND

Intraocular inflammation, commonly referred to as uveitis, is a prevalent ocular disease. The categorization of uveitis may be based on the prevailing anatomical site, which includes anterior, intermediate, and posterior uveitis. There exists a significant body of evidence indicating that T cells play a pivotal role in the pathogenesis of autoimmune uveitis. In addition to the presence of T cells, an elevation in levels of inflammatory cytokines and a reduction in regulatory cytokines were also noted. The primary pharmacological interventions for uveitis comprise of corticosteroids, methotrexate, anti-vascular endothelial growth factor (VEGF) agents, anti-tumor necrosis factor-alpha (TNF-α) antibodies, and sirolimus. These medications offer prompt alleviation for inflammation. Nevertheless, prolonged administration of corticosteroids invariably leads to unfavorable adverse reactions. The traditional topical corticosteroids exhibit certain limitations, including inadequate transcorneal permeation and low corneal retention, leading to reduced ocular bioavailability. Consequently, there is a growing inclination towards the creation of innovative steroid drug delivery systems with the aim of reducing the potential for adverse effects, while simultaneously enhancing the drug's corneal permeation and retention.

CONCLUSION

This review is an attempt to compile all the research work done so far in this field and provides a brief overview of the global efforts to develop innovative nanocarrier-based systems for corticosteroids.

MiR-223-3p attenuates M1 macrophage polarization via suppressing the Notch signaling pathway and NLRP3-mediated pyroptosis in experimental autoimmune uveitis

Autoimmune uveitis is an intraocular inflammatory disease with a high blindness rate in developed countries such as the United States. It is pressing to comprehend the pathogenesis of autoimmune uveitis and develop novel schemes for its treatment. In the present research, we demonstrated that the Notch signaling pathway was activated, and the level of miR-223-3p was significantly reduced in rats with experimental autoimmune uveitis (EAU) compared with the level of normal rats. To investigate the relationship between miR-223-3p and Notch signaling, EAU rats received miR-223-3p-carrying lentivirus, miR-223-3p vector-carrying lentivirus (miR-223-3p-N), and γ-secretase inhibitor (DAPT), respectively. The results of Q-PCR, immunological experiments, and flow cytometry analysis all support the hypothesis that both miR-223-3p and DAPT, a Notch signaling pathway inhibitor, had similar inhibitory effects on the EAU pathological process. That is to say, they could both inhibit the activation of the Notch signaling pathway via modulating recombination signal binding protein-Jκ (RBPJ) to restore the polarization imbalance of M/M2 macrophages in EAU rats. In addition, miR-223-3p could also inhibit NLRP3 inflammasome activation and inflammasome-induced pyroptosis in ocular tissues. Taken together, our findings indicate that miR-223-3p serves as an important regulator in M1 macrophage polarization and pyroptosis, thereby alleviating the inflammatory response in uveitis.

A review of investigated risk factors for developing equine recurrent uveitis

Equine recurrent uveitis (ERU) is an ocular inflammatory disease that can be difficult to manage clinically. As such, it is the leading cause of bilateral blindness for horses. ERU is suspected to have a complex autoimmune etiology with both environmental and genetic risk factors contributing to onset and disease progression in some or all cases. Work in recent years has aimed at unraveling the primary triggers, such as infectious agents and inherited breed-specific risk factors, for disease onset, persistence, and progression. This review has aimed at encompassing those factors that have been associated, implicated, or substantiated as contributors to ERU, as well as identifying areas for which additional knowledge is needed to better understand risk for disease onset and progression. A greater understanding of the risk factors for ERU will enable earlier detection and better prognosis through prevention and new therapeutics.

The emerging role of epigenetics and gut microbiota in Vogt-Koyanagi-Harada syndrome

Vogt-Koyanagi-Harada (VKH) syndrome is an autoimmune disorder characterized often by acute diffuse uveitis, also known as idiopathic uveoencephalitis. The associated complications can potentially affect multiple systems throughout the body, including eyes, ears, skin and nervous system. Although the pathogenesis of VKH syndrome remains unclear, it has been established that the various genetic factors, epigenetic factors and the imbalance in immune regulation can significantly contribute to the development of this disease. In addition, the experimental autoimmune uveitis (EAU) has been commonly used to further explore the pathogenesis of the disease. Herein, in this review article, we discuss about the major research advances made in understanding of the different epigenetic factors and gut microbes involved in the pathogenesis of VKH syndrome as well as EAU. The information discussed can help to better understand the pathogenesis of VKH syndrome, and thereby might provide a basis for finding novel molecular targets and innovative treatment strategies in the future.

Analyses of circRNA and mRNA Profiles in Vogt-Koyanagi-Harada Disease

Recent studies revealed that circular RNAs (circRNAs) are important in numerous biological process and involved in autoimmune diseases. However, their role in Vogt-Koyanagi-Harada (VKH) disease, a classical autoimmune disease, is not yet known. This research aimed to study the expression profile of mRNAs, microRNAs (miRNAs) and circRNAs and investigate the influence of circRNAs on the pathogenesis of VKH disease. We identified circRNAs, miRNAs, and mRNAs expression profiles in CD4⁺ T cells between 4 VKH patients and 3 healthy controls using the whole-transcriptome sequencing (RNA-seq) technique. We discovered that a total of 5088 mRNAs, 451 circRNAs and 433 miRNAs were differently expressed. The GO and KEGG pathway enrichment analyses were performed for significantly differentially expressed circRNAs and mRNAs. GSEA was conducted for all mRNAs. The functional enrichment suggested that the inflammatory response, the adaptive immune response, NF-kappa B signaling pathway, Th17 cell differentiation, Th1 and Th2 cell differentiation and T cell receptor signaling pathway were associated with VKH disease. In addition, based on the immune-related genes we screened, the circRNA-miRNA-mRNA ceRNA network was analyzed and constructed. Ten differently expressed mRNAs (LAT, ZAP70, ITK, ICOS, RASGRP1, PAG1, PLCG1, PRKCQ, LCK, CARD11) and 5 differently expressed circRNAs (hsa_circ_0033144, hsa_circ_0000233, hsa_circ_0000396, hsa_circ_0001924, hsa_circ_0001320) were selected to be validated by Real-time qPCR (RT-qPCR). The results of RT-qPCR turned out to be consistent with RNA-seq data. Further analysis showed that hsa_circ_0001320 and hsa_circ_0001924 may serve as crucial candidate marker genes of VKH disease. These results reveal that circRNAs may have a crucial immunomodulatory function in the pathophysiological process of VKH disease.

Epigenetic Modifications and Therapy in Uveitis

Uveitis is a sight-threatening intraocular inflammation, and the exact pathogenesis of uveitis is not yet clear. Recent studies, including multiple genome-wide association studies (GWASs), have identified genetic variations associated with the onset and progression of different types of uveitis, such as Vogt–Koyanagi–Harada (VKH) disease and Behcet’s disease (BD). However, epigenetic regulation has been shown to play key roles in the immunoregulation of uveitis, and epigenetic therapies are promising treatments for intraocular inflammation. In this review, we summarize recent advances in identifying epigenetic programs that cooperate with the physiology of intraocular immune responses and the pathology of intraocular inflammation. These attempts to understand the epigenetic mechanisms of uveitis may provide hope for the future development of epigenetic therapies for these devastating intraocular inflammatory conditions.

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.

Regulatory roles of differentially expressed MicroRNAs in metabolic processes in negative Lens-induced myopia Guinea pigs

BACKGROUND

Myopia is one of the most common vision defects worldwide. microRNAs can regulate the target gene expression, influencing the development of diseases.

RESULTS

To investigate the alterations of microRNA profiling in negative lens-induced myopia (NLIM) guinea pigs and to explore the regulatory role of microRNAs in the occurrence and the development of myopia, we first established the NLIM guinea pig model after induction for 2 weeks. Further, we isolated sclera to purify total messenger RNA (mRNA) in both NLIM and NLIM fellow sclera. Using next generation sequencing technique and bioinformatics analysis, we identified the differentially expressed microRNAs in NLIM guinea pigs, performed the bioinformatics annotation for the differentially expressed microRNAs, and validated the expression of differentially expressed microRNAs. As a result, we successfully established an NLIM model in guinea pigs, identified 27 differentially expressed microRNAs in NLIM guinea pig sclera, including 10 upregulated and 17 downregulated microRNAs. The KEGG annotation showed the main signaling pathways were closely associated with PPAR signaling, pyruvate and propanoate metabolisms, and TGF-beta signaling pathways.

CONCLUSIONS

Our findings indicate that the development of myopia is mainly involved in the disorder of metabolic processes in NLIM guinea pigs. The PPAR signaling, pyruvate and propanoate metabolism pathways may play roles in the development of myopia.

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.

DAPT reverses the Th17/Treg imbalance in experimental autoimmune uveitis in vitro via inhibiting Notch signaling pathway

Uveitis is the most common cause in inflammatory eye diseases that can lead to visual impairment even blindness worldwide. T helper (Th) 17 and regulatory T (Treg) cells are critical mediators for immune response. Notch signaling can regulate the cell differentiation, playing a role in the pathogenesis of the diseases. In this study, we measured the expression levels of Notch1, DLL4, IL-10, IL-17, RORγt and Foxp3 in T cells from lymph node, spleen and eye tissues in experimental autoimmune uveitis (EAU) rats in vitro, determined the ratios of CD4⁺/CD8⁺ and Th17/Treg. Moreover, we also investigated the effect of Notch signaling inhibitor N-(N-(3,5-Difluorophenacetyl-L-alanyl))-S-phenylglycine t-Butyl Ester (DAPT) on Notch1, DLL4 expression and on Th17, Treg cell differentiation. The results indicated that the pathogenesis of uveitis accompanied by the elevated expression of Notch1, DLL4, IL-10, IL-17, RORγt, and Foxp3 as well as the imbalanced CD4⁺/CD8⁺ and Th17/Treg ratios. By contrast, inhibition of Notch signaling by DAPT can efficiently decrease Th17 cell response, downregulate the expression of Notch1, DLL4, IL-17 and the transcription of RORγt, reduce Th17 levels and restore the CD4⁺/CD8⁺, Th17/Treg balance. Moreover, DAPT can also inhibit Th17 cell differentiation in healthy rats, though the inhibitory capacity of Th17, Treg differentiation is less than that in EAU rats. Overall, Notch signaling activation can lead to the disturbed Th17/Treg balance in uveitis, whereas inhibition of Notch signaling can ameliorate the inflammatory response and may be a potential immunoregulatory strategy in patients with uveitis.

MiRNA as biomarker for uveitis - A systematic review of the literature

AIM

A systematic review of miRNA profiling studies in uveitis.

METHODS

Literature search strategy - Pubmed central central database, using miRNA/microRNA and intraocular inflammation/uveitis as keywords.

RESULTS

We found twenty publications regarding the experimental and clinical use of miRNA in uveitis, published between 2011 and 2018.

CONCLUSION

The publications regarding the role of miRNA in uveitis are very scarce, but provide some valuable information about the potential new mechanisms in uveitis. Some of the identified miRNAs in different uveitis entities could serve as a biomarker of intraocular inflammation. Possible candidate miRNAs could be let-7e, miRNA-1, miR-9-3, miR-20a-5p, miR-23a, mir-29a-3p, miR-140-5p, miR-143, miR-146a and miR-146a-5p, miR-155, miR-182 and miR-182-5p, miR-196a2, miR-205, miR-223-3p, miR-301a. MiR-146a, miR-146a-5p, miR-155, miR-182, miR-223-3p, have been found to be possibly associated with uveitis disease in both, human and animal species.

Regulatory Role of rno-miR-30b-5p in IL-10 and Toll-like Receptor 4 Expressions of T Lymphocytes in Experimental Autoimmune Uveitis In Vitro

Uveitis is a serious eye disease that usually damages young adult's health. MicroRNAs (miRNAs) are a class of small noncoding RNAs which regulate messenger RNA (mRNA) expression. It is predicted that rno-miR-30b-5p can regulate the expressions of interleukin-10 (IL-10) and Toll-like receptor 4 (TLR4). In this study, the regulatory role of rno-miR-30b-5p in IL-10 and TLR4 gene expressions was validated using luciferase activity assay. Further, the inflammatory manifestation of the anterior segment and pathological examination of the eye were explored in experimental autoimmune uveitis (EAU) rats. Meanwhile, the levels of rno-miR-30b-5p in eye tissues, spleen, and lymph nodes were measured using quantitative PCR (Q-PCR). IL-10 and TLR4 in spleen and lymph nodes were further separately determined by using Q-PCR and Enzyme-Linked Immunosorbent Assay (ELISA). Moreover, rno-miR-30b-5p mimic and its inhibitor were separately transfected into purified T cells, and the levels of IL-10 and TLR4 were detected using PCR, flow cytometry, and ELISA techniques. Results indicate that rno-miR-30b-5p was downregulated in spleen, lymph nodes, and eye tissues whereas the expressions of IL-10 and TLR4 at mRNA and protein levels were upregulated. The levels of IL-10 and TLR4 were negatively correlated to rno-miR-30b-5p levels. The result of in vitro cell transfection experiment indicates that IL-10 and TLR4 expressions were inhibited at mRNA and protein levels after T cells incubated with rno-miR-30b-5p mimic. However, the IL-10 and TLR4 mRNA levels were upregulated in purified T cells from spleen and lymph nodes after treatment with miR-30b-5p antagonist. In addition, there was no evident change of IL-10 and TLR4 proteins in spleen and lymph node T cells between EAU control and negative treatment groups. Flow cytometry analysis revealed that rno-miR-30b-5p mimic could reduce the number of both IL-10 and TLR4 positive cells, whereas rno-miR-30b-5p inhibitor could increase the number of IL-10 and TLR4 positive cells. Our study demonstrates that rno-miR-30b-5p influences the development of uveitis by regulating the level of IL-10 and TLR4 positive cells, thereby playing a role in the pathogenesis of uveitis.

Integrative analysis of genome-wide association studies and gene expression analysis identifies pathways associated with rheumatoid arthritis

Rheumatoid arthritis (RA) is a complex and systematic autoimmune disease, which is usually influenced by both genetic and environmental factors. Pathway analyses based on a single data type such as microarray data or SNP data have successfully revealed some biology pathways associated with RA. However, we found that the pathway analysis based on a single data type only provide limited understanding about the pathogenesis of RA. Gene-disease association is usually caused by many ways, such as genotype, gene expression and so on. Therefore, the integrative analysis method combining multiple levels of evidence can more precisely and comprehensively identify the pathway associations. In this study, we performed a pathway analysis by integrating GWAS and gene expression analysis to detect the RA-related pathways. The integrative analysis identified 28 pathways associated with RA. Among these pathways, 18 pathways were also found by both GWAS and gene expression analysis, 7 pathways are novel RA-related pathways, such as B cell receptor signaling pathway, Toll-like receptor signaling pathway, Fc gamma R-mediated phagocytosis and so on. Compared with pathway analyses using only one type genomic data, we found integrative analysis can increase the power to identify the real associations and provided more stable and accurate results. We believe these results will contribute to perform future genetic studies in RA pathogenesis and may promote the development of new therapeutic strategies by targeting these pathways.

Immunomodulatory effects of Longdan Xiegan Tang on CD4+/CD8+ T cells and associated inflammatory cytokines in rats with experimental autoimmune uveitis

Longdan Xiegan Tang (LXT) is a mixture of herbal extracts commonly used in traditional Chinese medicine that may exert immunomodulatory effects for the treatment of autoimmune diseases. However, the detailed mechanisms that mediate the actions of LXT are unclear. The present study induced an experimental autoimmune uveitis (EAU) model in Lewis rats via injection of IRBP1177‑1191 emulsion. The model was used to investigate the effects of LXT on EAU rats and assess the efficacy of LXT by measuring clinical manifestations and histopathological changes caused by EAU. Additionally, alterations in the ratio of CD4+/CD8+‑T cells were determined by flow cytometry, and the expression of interferon (IFN)‑γ, interleukin (IL)‑17, IL‑10 and tumor necrosis factor (TNF)‑α were measured using reverse transcription‑quantitative polymerase chain reaction and enzyme‑linked immunosorbent assay analysis. The results of the present study demonstrate that LXT can efficiently alleviate the symptoms of EAU, inhibit the differentiation of uveitogenic CD4+ T cells and reduce the expression of proinflammatory cytokines, including IFN‑γ, IL‑17 and TNF‑α. Furthermore, LXT promotes the production of IL‑10 and accelerates the recovery of EAU, indicating that the immunomodulatory effects of LXT may potentially be used for the treatment of uveitis.