Iranian Journal of Allergy, Asthma and Immunology
Volume:22 Issue: 6, Dec 2023

Scientific research over the past decades has proven the pivotal role of long non-coding RNAs (LncRNAs) in regulating gene expression. The immune responses are controlled through the interaction of pro-inflammatory (predominance of T helper 17 cells (Th17)) and anti-inflammatory cytokines excretion (predominance of Regulatory T cells (Treg)). Recent studies have marked the impact of many diverse LncRNAs on Treg/Th17 imbalances. Moreover, some of the roots and causes of human diseases can be associated with the alterations in the Th17/Treg ratio. In this review study, we overviewed the association between LncRNAs and Th17/Treg, with the potential of providing novel prognostic and diagnostic biomarkers and promising therapeutic targets in various diseases, particularly cancer.

The aim of asthma treatment is to reduce airway inflammation by avoiding environmental triggers and using daily anti-inflammatory medications. This study aimed to compare the effects of fluticasone propionate (FP) and budesonide (Bud) on the clinical symptoms and control of asthma in children with moderate to severe asthma. In this open-label study, children with moderate to severe asthma were randomly selected to receive either FP 250 mcg or Bud 400 mcg for 3 months. Asthma control test scores were measured in both groups monthly. The clinical symptoms, drug adherence, and rescue medication were also evaluated. A total of 50 patients with ages between 4 and 7 years old were included in the study (25 cases received Bud and 25 cases received FP). Asthma control test scores, daily and nocturnal symptoms, and cough rates were significantly improved in both groups. The average asthma control scores for the fluticasone group were 21.68±3.32 in the second month and 24.84±2.67 in the third month, whereas the budesonide group had scores of 18.52±3.32 and 22.48±4.12 during the same periods. These variances were statistically significant. Additionally, the requirement for salbutamol use was notably reduced in the fluticasone group compared to the budesonide group throughout all three months. The efficacy of fluticasone propionate in decreasing the need for rescue medication and enhancing asthma control test scores was markedly superior to that of budesonide.

MicroRNAs (miRs) play a role in several diseases, such as rheumatoid arthritis (RA). The purpose of this study was to discover new microRNAs and investigate their involvement in RA, examining their connections with inflammation and metabolic markers. New microRNAs related to RA were predicted using Mirbase and TargetScan databases based on RA target genes. The relationships between miRNAs and targets were visualized with Cytoscape software. Real-time polymerase chain reaction confirmed detectable miRNAs and metabolic factors were assessed using immunoassay and spectrometry methods in RA patients and healthy subjects. Four microRNAs (hsa-miR-153-5p, hsa-miR-4270, hsa-miR-4441, and hsa-miR-6754-5p) showed the highest correlation with RA target genes among millions of microRNAs. The expression of miR-146b (fold change=1.8) and miR-4441 (fold change=1.7) was notably reduced, while miR-4270 showed upregulation (fold change=1.8) in plasma from RA patients compared to healthy individuals. MiR-6754 exhibited a decrease (fold change=1.3) but was statistically insignificant. MiR-153-5p expression was undetectable in plasma. Receiver operating characteristic (ROC) curve analysis indicated that miR-4441, with an area under the ROC curve (AUC) of 0.7728, and miR-4270 (AUC=0.7353) were promising biomarkers for RA. The expression of these studied miRNAs significantly correlated with essential clinical characteristics, including liver enzymes, cholesterol, phosphorus, and vitamin D3. Our findings suggest that miR-4270 and miR-4441, present in the circulation, exhibit distinct expression patterns in RA. These microRNAs may serve as links between inflammation and metabolism and represent promising new biomarkers for this disease.

Asthma, a prevalent chronic airway inflammatory condition, poses a significant health challenge. In this study, we delved into the regulatory mechanisms governing asthma, focusing on Methyltransferase-like 3 (METTL3). Through an ovalbumin (OVA)-induced mouse model and interleukin-13 (IL-13)-induced cell model, we mimicked the in vivo and in vitro functions of METTL3 in asthma. Our research revealed that METTL3 expression significantly decreased in asthma-induced mice and IL-13-stimulated cells compared to the control group. Moreover, METTL3 overexpression enhanced bronchial epithelial cell viability and proliferation. Mechanistically, we observed elevated levels of total iron, Fe2+, malondialdehyde (MDA), lipid reactive oxygen species (ROS), alongside reduced glutathione (GSH) levels in IL-13-stimulated cells. Remarkably, METTL3 overexpression counteracted these effects, suggesting a pivotal role in mitigating asthma-related oxidative stress. Furthermore, our study highlighted the involvement of N6-methyladenosine methylation (m6A) modification, where METTL3 regulated the m6A modification of glutathione peroxidase 4 (GPX4) RNA, impacting RNA stability. Knockdown of METTL3 suppressed m6A modification on GPX4 RNA, impairing its stability and contributing to IL-13-induced ferroptosis. Interestingly, METTL3 overexpression not only inhibited cell ferroptosis but also alleviated asthma symptoms. Our findings shed light on the epigenetic regulation of asthma through METTL3-mediated m6A modification, offering potential therapeutic avenues for this prevalent inflammatory disease.

Increasing the efficacy of allergen-specific intranasal immunotherapy (INIT) has recently been the main goal of several studies to establish this route as a safe delivery method through mucosal pathways. In this case, the present study evaluated the potential of INIT using ovalbumin (OVA)-loaded mesenchymal stromal/stem cell (MSC)-derived exosomes (Exo-OVA) in an allergic asthma mouse model. Together with control groups, sensitized Balb/c mice underwent intranasal immunotherapy with Exo-OVA (10 μg OVA per dose) for three consecutive weeks. Serum-specific immunoglobulin E (IgE) levels, transforming growth factor-beta (TGF-β), interleukin (IL)-4, and interferon-gamma (IFN-γ) production by cultured spleen cells, lung histopathologic analysis, and nasopharyngeal lavage fluid cellular examinations were then conducted. The results showed that INIT using Exo-OVA significantly increased IFN-γ and TGF-β secretion, while allergen-specific IgE and IL-4 production were dramatically decreased compared to the control group receiving phosphate-buffered saline. In addition, the eosinophil and total cell counts in the nasopharyngeal lavage fluid were reduced, and inflammatory conditions and cell accumulation in lung tissue were ameliorated. In conclusion, the Exo-OVA improved the INIT efficacy compared to free OVA. Therefore, this formulation could be introduced as an effective approach for immunomodulatory purposes with a shorter treatment duration and reduced side effects.

Multiple sclerosis (MS) is an inflammatory disorder impacting the central nervous system, with cytokines significantly influencing its pathogenesis. This study investigates the effect of curcumin and its semisynthetic derivative F-curcumin on cytokine gene expression in autoimmune encephalomyelitis (EAE) mouse models of MS. We assessed the expression levels of specific cytokines including interleukin (IL)-1β, IL-4, IL-10, IL-17, interferon-γ (IFN-γ), and transforming growth factor-β (TGF-β), alongside key transcription factors for helper T cells (T-bet, GATA-3, RORγt, and FoxP3) in both the spinal cord and spleen. Treatment with curcumin and F-curcumin significantly ameliorated the severity and onset of EAE. Notably, mice administered with either compound showed a substantial decrease in the expression of genes encoding IL-1 (2 folds), IFN-γ (2 and 4 folds), and IL-17 (2.5 and 3.5 folds), alongside a marked increase in TGF-β (7 folds) and IL-10 (4 and 6 folds) levels. Additionally, the gene expression of T cell-derived transcription factors nearly mirrored the changes observed in pro-inflammatory and anti-inflammatory cytokines across the groups. The F-curcumin-treated group exhibited more pronounced results. In conclusion, curcumin and F-curcumin significantly modulate cytokine gene expression during EAE induction, potentially alleviating inflammation in MS, with F-curcumin showing a more substantial effect.

Pathogen recognition receptors (PRRs), which play a crucial role in responding to pathogens, affect the function of mesenchymal stem cells (MSCs). One important group of PRRs is the toll-like receptors (TLRs). When PRRs are activated, they can alter the expression of specific surface markers, the ability of MSCs to differentiate, and the types of substances they secrete. These modifications in MSC function may have unexpected consequences for patients. In this study, we examined how Leishmania major (L. major) promastigotes affect the properties of MSCs. MSCs were isolated from adipose tissue and categorized into two groups: one group left untreated and the other group exposed to L. major. Giemsa staining was employed to accurately quantify the number of parasites that entered the cells. After 72 hours, real-time polymerase chain reaction was utilized to assess the expression of TLRs. Additionally, the flow cytometry technique was used to evaluate the expression of surface markers on the MSCs. Our results showed that MSCs can engulf parasites and increase the expression of TLR4 and TLR6. The pro-inflammatory cytokine increased, and the transforming growth factor-β decreased significantly. The parasite exposure increased reactive oxygen species production. Additionally, the percentage of cluster differentiation (CD) 73 decreased, and the mean fluorescent index of CD29 and CD73 was down-regulated by L. major. Exposure to parasites diminishes the immunomodulatory capacity of MSCs. This discovery holds significance for the application of MSCs in addressing parasite infections and underscores the need for additional research to enhance their therapeutic effectiveness.

Chronic granulomatous disease (CGD) presents with granuloma formation and lethal infections. It is inherited in an autosomal or X-linked recessive pattern. We describe a 10-month-old patient with a fatal secondary HLH as a CGD primary manifestation. We carried out an autopsy and found noncaseating granulomas, an aspergilloma in the lung, and hemophagocytosis. We performed a DHR assay on the patient’s mother and grandmother, showing a bimodal pattern conclusive of X-linked CGD. Thus, our definitive diagnosis was CGD complicated by macrophage activation syndrome. CGD is caused by phagocytes’ inability to control pathogens, resulting in granulomas. Secondary HLH is a severe complication and could be characterized by the proliferation of macrophages and T lymphocytes and the production of proinflammatory cytokines. The early suspicion of this presentation helps establish a specific treatment, and the study of the carriers helps determine the etiology.

Kimura disease (KD), also known as eosinophilic lymphogranuloma, is a rare chronic inflammatory or allergic disease. It can present with immune-related diseases such as nephrotic syndrome, asthma, and ankylosing spondylitis. In this study, we report a case of KD combined with immunoglobulin A nephropathy that first presented as a mass in the inguinal region, followed by recurrent renal involvement. Previous reports suggested that renal involvement caused by KD was due to direct infiltration of eosinophils; however, in this case, no eosinophil infiltration was found in the renal tissue after renal biopsy. This observation reminds us to approach the case from an immune-related molecular perspective to investigate the exact cause of renal damage due to KD.