Indications and effects of biological agents in the treatment of noninfectious uveitis

Single-cell RNA sequencing indicates AP-1 as a potential therapeutic target for autoimmune uveitis

Autoimmune uveitis (AU) is a sight-threatening eye disease, marked by a complex pathogenesis and limited treatment options. Herein, we conducted single-cell RNA sequencing (scRNA-seq) on the spleen and cervical draining lymph nodes (CDLNs) of both normal and experimental autoimmune uveitis (EAU) mice and found common alterations in celluar composition and transcriptional regulation occurred throughout the EAU process. Moreover, we identified activator protein-1 (AP-1) as a pivotal disease-related molecule in the pathogenesis of EAU. Inhibiting AP-1 alleviated symptoms of EAU and reduced the retina infiltration of T helper 17 cells (Th17) and Th1 cells. Additionally, following treatment with the AP-1 inhibitor, both the spleen and CDLNs showed decreased Th17 and Th1 cell proportions. Meanwhile, in vitro studies revealed that treatment with AP-1 inhibitor reduced the level of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-23 (IL-23), two pivotal molecules implicated in the Th17 cell pathogenicity, during EAU. The adoptive transfer experiment also showed that inhibiting AP-1 in CD4+ T cells suppressed their ability to elicit EAU. Altogether, our study demonstrates that AP-1 might involved in EAU pathogenesis by supporting Th17 cell pathogenicity via the GM-CSF/IL-23 feedback loop. Thus, AP-1 inhibition might be a novel treatment strategy for uveitis.

Cytokines in Immune-mediated "Non-infectious" Uveitis

Uveitis is a significant cause of ocular morbidity and accounts for approximately 5 - 10% of visual impairments worldwide, particularly among the working-age population. Infections are the cause of ~ 50% cases of uveitis, but it has been suggested that infection might also be implicated in the pathogenesis of immune-mediated "non-infectious" uveitis. There is growing evidence that cytokines (i.e., interleukins, interferons, etc.) are key mediators of immune-mediated "non-infectious" uveitis. For example, activation of the interleukin-23/interleukin-17 signalling pathway is involved in immune-mediated "non-infectious" uveitis. Studies in animal models have been important in investigating the role of cytokines in uveitis. Recent studies of clinical samples from patients with uveitis have allowed the measurement of a considerable array of cytokines even from very small sample volumes (e.g., aqueous and vitreous humour). The identification of complex patterns of cytokines may contribute to a better understanding of their potential pathogenetic role in uveitis as well as to an improved diagnostic and therapeutic approach to treat these potentially blinding pathologies. This review provides further insights into the putative pathobiological role of cytokines in immune-mediated "non-infectious" uveitis.

Dimethyl itaconate inhibits antigen-specific Th17 cell responses and autoimmune inflammation via modulating NRF2/STAT3 signaling

Pathogenic Th17 cells play a crucial role in autoimmune diseases like uveitis and its animal model, experimental autoimmune uveitis (EAU). Dimethyl itaconate (DMI) possesses potent anti-inflammatory effects. However, there is still a lack of knowledge about the role of DMI in regulating pathogenic Th17 cells and EAU. Here, we reported that intraperitoneal administration of DMI significantly inhibited the severity of EAU via selectively suppressing Th17 cell responses. In vitro antigen stimulation studies revealed that DMI dramatically decreased the frequencies and function of antigen-specific Th17, but not Th1, cells. Moreover, DMI hampered the differentiation of naive CD4+ T cells toward pathogenic Th17 cells. DMI-treated DCs produced less IL-1β, IL-6, and IL-23, and displayed an impaired ability to stimulate antigen-specific Th17 activation. Mechanistically, DMI activated the NRF2/HO-1 pathway and suppressed STAT3 signaling, which subsequently restrains p-STAT3 nuclear translocation, leading to decreased pathogenic Th17 cell responses. Thus, we have identified an important role for DMI in regulating pathogenic Th17 cells, supporting DMI as a promising therapy in Th17 cell-driven autoimmune diseases including uveitis.

Noninfectious Uveitis in Rheumatology: Patterns, Treatment, and Outcomes

OBJECTIVES

The present study aimed to determine the pattern and cause of noninfectious uveitis in rheumatology practice. The secondary objective was to identify the pattern of treatment and outcomes.

MATERIALS AND METHODS

This retrospective cross-sectional study was conducted in the Department of Rheumatology, National Hospital and Medical Centre, Lahore, Pakistan. After receiving consent, electronic medical records (EMRs) of all patients with a diagnosis of noninfectious uveitis (NIU) from November 2019 to January 2023 were reviewed, and a total of 52 patients labeled as having noninfectious uveitis were identified. The collected data included age at diagnosis, anatomical location of uveitis, associated systemic disease, used medications, and outcomes. All cases had been diagnosed and assessed mutually by a rheumatologist and an ophthalmologist using the International Uveitis Study Group classification system to classify the pattern of uveitis by location, clinical course, and laterality and rule out the possibility of other ophthalmologic diseases. Disease activity was defined using the Standardization of Uveitis Nomenclature (SUN) guidelines. Data was analyzed on SPSS Statistics version 23 (IBM Corp, Armonk, NY, USA).

RESULTS

The mean age of the patients in this study was 36.02 ± 43.31 years, with 31 (59.6%) male patients. Anterior uveitis was the most common type observed among the patients at 55.8%, panuveitis was found in 25%, intermediate uveitis and posterior uveitis were seen in 9.6% each. Based on laterality, unilateral eye involvement was identified in 53.8% of patients. Spondyloarthritis (SpA) and idiopathic uveitis were observed in 34.6% and 28.8%, respectively. In this study, 28 (54.9%) patients were on conventional disease-modifying antirheumatic drugs (cDMARDDs), and 23 (45.1%) were on biological DMARDs. In the biologics group, 82% of patients were in remission in comparison to 60% in the cDMARDs group.

CONCLUSION

To the best of our knowledge, this is the first report on noninfectious uveitis in the Pakistani population. The study concluded that anterior uveitis is the most common type of uveitis and is more common in males. Spondyloarthropathy is one of the most common underlying systemic diseases. Human leukocyte antigen (HLA)-B27 is associated more with uveitis. Biologics are more effective than cDMARDs in controlling the disease. Collaborative work between different specialties resulted in early diagnosis of underlying systemic disease, better management plans, and disease outcomes. To obtain further details on noninfectious uveitis, a population-based study is needed in Pakistan.

Unveiling the prominent roles of circular RNAs ubiquitin binding associated protein 2 in cancers

Circular RNAs (circRNAs), a novel type of covalently closed non-coding RNAs, are widely expressed in eukaryotes and viruses. Accumulating evidence has shown that circRNAs play key roles in the pathophysiological changes process of human diseases and can affect cancer development and progression through regulating target genes expression, linear RNA transcription and protein generation. Recent studies had found that circRNA-UBAP2 (ubiquitin binding associated protein 2) was aberrantly expressed in various human tumors and could affect tumor cells proliferation, migration, invasion, cell cycle, anti-apoptosis, radioresistance, chemoresistance and other malignant biological behavioral progress. Mechanistic studies further revealed that circUBAP2 could affect the occurrence and development of human tumors through multiple different molecular regulatory pathways in vivo and in vitro. In addition, the abnormal expression of circUBAP2 was significantly correlated with the clinicopathological characteristics of malignant tumors and had potential value as biomarkers for the diagnosis and prognosis evaluation of cancer patients, which deserved further study. This review had summarized and discussed the oncogenic roles and clinical performances of circUBAP2 in various human malignancies with a focus on biological functions and molecular mechanisms, which could help to elevate the understanding to the roles of circRNAs and continue subsequent studies on circUBAP2.