Search Results (9,461)

Arrhythmogenic cardiomyopathy (ACM; MIM #107970) is a primitive heart muscle disease characterized by progressive myocardial loss and fibrosis or fibrofatty replacement, predisposing patients to ventricular arrhythmias, sudden cardiac death, and heart failure. Despite advances in imaging and genetics, early diagnosis remains challenging due to incomplete penetrance, variable phenotypic expressivity, and the fact that fatal arrhythmic events may often occur in the early stages of the disease. In this context, the identification of reliable biomarkers could enhance diagnostic accuracy, support risk stratification, and guide clinical management. This narrative review examines the current landscape of potential and emerging biomarkers in ACM, including troponins, natriuretic peptides, inflammatory proteins, microRNAs, fibrosis-related markers, and other molecules. Several of these biomarkers have demonstrated associations with disease severity, arrhythmic burden, or structural progression, although their routine clinical utility remains limited. The increasing relevance of genetic testing and non-invasive tissue characterization—particularly through cardiac imaging techniques—should also be emphasized as part of a multimodal diagnostic strategy in which biomarkers may play a complementary role. Although no single biomarker currently meets the criteria for a standalone diagnostic application, ongoing research into multi-marker panels and novel molecular targets offers promising perspectives. In conclusion, the integration of circulating biomarkers with imaging findings, genetic data, and clinical parameters may open new avenues for improving early detection and supporting personalized therapeutic strategies in patients with suspected ACM. Full article

Obstructive sleep apnea (OSA) is a chronic respiratory disorder characterized by intermittent hypoxia and is strongly associated with the development of type 2 diabetes mellitus (T2DM). Despite this link, the molecular mechanisms underlying OSA-related metabolic dysregulation remain incompletely understood. The aim of the study was to investigate the role of hypoxia-sensitive microRNAs, sirtuin 1 (SIRT1), and adiponectin in the metabolic profile of OSA patients, with and without T2DM. A total of 87 participants were stratified into three groups: OSA, OSA + T2DM, and healthy controls. Blood samples were collected in the evening and morning, and after continuous positive airway pressure (CPAP) therapy. Expression levels of miRNAs and SIRT1 were measured via RT-qPCR; adiponectin was quantified by ELISA. Significantly reduced expression of miRNA-181a and miRNA-199a was observed in the OSA + T2DM group compared to OSA (p = 0.035 and p = 0.042, respectively). In contrast, SIRT1 expression was highest in the OSA + T2DM group (p < 0.01), while adiponectin concentrations was lowest in this group and the highest among healthy controls (p = 0.001). Despite increased SIRT1 in OSA + T2DM patients, the parallel increase in adiponectin was not observed. Additionally, expression of SIRT1 was significantly increased in OSA patients who were taking metformin (n = 23) vs. patients without metformin (n = 32) 77.315 vs. 437.08 (p = 0.037). CPAP therapy had significant influence only on miRNA-181a—expression was increased after long-term treatment (p = 0.047). Increased miRNA-181a expression in patients with OSA is related to decreased SIRT1 expression, which may lead to T2DM development. Surprisingly, the expression of SIRT1 is significantly higher and expression of hypoxia-sensitive miRNAs is significantly lower in patients with already developed T2DM, which might be explained by metformin intake. Full article

Atopic dermatitis (AD) is the most common inflammatory skin disease in the pediatric population. In recent years, the role of microRNAs in inflammatory and immunological mechanisms as specific biomarkers of AD has received growing attention. The aim of the present study was a quantitative assessment of serum expression levels of miR-100, miR-224 and miR-155 in children with AD compared with healthy peers, and an analysis of their potential associations with clinical disease phenotype, severity of skin lesions (SCORAD), cytokine profile, immunological parameters and the presence of concomitant allergic diseases. The study included 12 children with AD and 9 healthy children. Selected miRNAs were isolated from serum, followed by reverse transcription using universal primers and quantification by qRT-PCR. Children with AD exhibited significantly higher expression levels of miR-155 compared with controls (p = 0.003). No statistically significant differences were observed for miR-100 and miR-224. miR-100 expression was significantly higher in children with a positive history of inhalant allergy compared with those without such a diagnosis (p = 0.014). A positive correlation was observed between miR-100 levels and the percentage of eosinophils (r = 0.599; p = 0.052) as well as absolute eosinophil count (r = 0.600; p = 0.051). MiR-155 is significantly upregulated in children with AD suggesting it as a candidate biomarker worthy of further investigation in larger cohorts. Although miR-100 did not differentiate the groups, its correlation with eosinophilia and inhalant allergy suggests a role in disease phenotyping. Full article

Background: Head and neck squamous cell carcinoma (HNSCC) is a prevalent malignancy with poor clinical outcomes. microRNA-7-5p (miR-7-5p) has been described as both a tumour suppressor and an oncomiR depending on the tissue context, but its role in HNSCC remains unclear. This study aimed to clarify the clinical significance and biological function of miR-7-5p in HNSCC by integrating data from multiple sources. Methods: A systematic review of the literature was conducted to identify studies analysing miRNA expression in human head and neck tissues. A meta-analysis of individual patient data from Gene Expression Omnibus (GEO), ArrayExpress, and The Cancer Genome Atlas (TCGA) was performed to assess miR-7-5p expression in tumours and normal tissues, and its associations with clinical parameters and prognostic outcomes. Bioinformatics analyses were used to predict miR-7-5p target genes, classify hub genes, and perform gene ontology enrichment analysis. MicroRNA in situ hybridisation (miRNA ISH) and real-time quantitative PCR (RT-qPCR) were conducted on tissue samples, HNSCC cell lines, and an in vitro model of oral oncogenesis to validate miR-7-5p expression patterns. Results: miR-7-5p was significantly upregulated in tumours compared to normal tissues and associated with larger tumour size, HPV-negative status, poor disease-specific survival, and shorter progression-free intervals. Bioinformatics analysis highlighted miR-7-5p target genes enriched in pathways related to cell growth, survival, and tumourigenesis. Despite evidence supporting the anti-cancer role of exogenous miR-7-5p in preclinical models, the observed endogenous upregulation in tumours suggests that miR-7-5p expression may represent a compensatory or stress-responsive mechanism during tumourigenesis, rather than acting as a primary oncogenic driver. Conclusions: This study provides new insights into the complex role of miR-7-5p in HNSCC, supporting its potential as both a biomarker and a therapeutic target. Understanding the context-specific functions of miR-7-5p is essential for its development as an RNA-based therapeutic in HNSCC. Full article

Background: Invasive fungal infections (IFIs) remain a major cause of morbidity and mortality among immunocompromised patients, despite advances in antifungal therapy. Conventional diagnostics are limited, highlighting the need for novel biomarkers. Circulating microRNAs (miRNAs) and cell-free DNA (cfDNA) have emerged as promising tools due to their roles in immune regulation, pathogen–host interactions, and disease monitoring. This systematic review and meta-analysis evaluate their diagnostic and prognostic potential in fungal infections. Methods: A systematic search of PubMed, Web of Science, SCOPUS, and EMBASE was conducted up to May 2025 in line with PRISMA guidelines (PROSPERO protocol CRD42021287150). Eligible studies included clinical research on confirmed fungal infections assessing cfDNA or miRNAs. Random-effects meta-analyses were performed for cfDNA, and miRNA findings were synthesized descriptively. Results: In total, 526 studies were included. cfDNA positivity was observed in 12% of all tested samples (95% CI: 0.06–0.22) and in 79% of patients with proven fungal infections (95% CI: 0.62–0.90), supporting its value as a minimally invasive, culture-independent diagnostic marker. Six studies on miRNAs identified disease-specific signatures, including miR-132 and miRNA panels for aspergillosis, with high diagnostic accuracy (AUC ≥ 0.98). miR-146a, miR-223, and miR-545 further correlated with prognosis and mortality. Conclusions: cfDNA and miRNAs show strong potential for early diagnosis, prognosis, and treatment monitoring in IFIs. Standardized methodologies and large-scale validation are essential for clinical translation. Full article

Heart failure (HF) remains a major cause of mortality despite the advances in pharmacological treatment. Anticoagulation therapies, including Clopidogrel, Aspirin, Warfarin, and novel oral anticoagulants (NOACs) such as Apixaban, Rivaroxaban, Edoxaban, and Dabigatran, are frequently administered to HF patients to prevent thromboembolism and adverse, life-threatening outcomes (e.g., stroke and myocardial infarction). In these settings, drug resistance and variability in responsivity to therapeutic approaches are challenging issues. Recent studies suggest that non-coding RNAs, particularly microRNAs (miRs) may play a modulatory role in HF therapy context, affecting drug efficacy. Specific miRs have been associated with resistance to Clopidogrel (e.g., miR-223 and miR-26a), Aspirin (e.g., miR-19b-1-5p and miR-92a) and Warfarin (e.g., miR-133 and miR-137). Moreover, Digoxin, a cardiac glycoside acting also over bleeding risk, upregulates miR-132, which is involved in HF-associated cardiac alteration and hypertrophy. Evidence linking miR expression to NOAC pharmacodynamics, cardiac remodeling and regulation of the coagulation is growing. These findings highlight the need of deeply harnessing the potential of miRs as predictive biomarkers or therapeutic targets in HF. Improving the knowledge on the relationship between miR and anticoagulant drugs in HF patients will contribute to personalization of the anticoagulant therapies, aimed at enhancing patient responsivity and minimizing adverse effects, ultimately improving patient life quality. Full article

Exercise activates many metabolic and signaling pathways in skeletal muscle and other tissues and cells, causing numerous systemic beneficial metabolic effects. Traditionally recognized for their principal role in oxygen (O₂) transport, erythrocytes have emerged as dynamic regulators of vascular homeostasis. Beyond their respiratory function, erythrocytes modulate vascular tone through crosstalk with other cells and tissues, particularly under hypoxia and physical exercise. This regulatory capacity is primarily mediated through the controlled release in the bloodstream of adenosine triphosphate (ATP) and nitric oxide (NO), two potent vasodilators that contribute significantly to matching oxygen supply with tissue metabolic demand. Emerging evidence suggests that many other erythrocyte-released molecules may act as additional factors involved in tissue-erythrocyte crosstalk. This review highlights erythrocytes as active contributors to exercise-induced adaptations through their exocrine signaling. Full article

Background/Objectives: Spheroid cultures in Matrigel are routinely used to study cell behaviour in complex 3D settings, thereby generating preclinical models of disease. Ideally, researchers would like to modulate gene expression ‘in situ’ for testing novel gene therapies while conserving the spheroid architecture. Here, we aim to provide an efficient method to transfect small RNAs (such as microRNAs and small interfering RNAs, i.e., siRNAs) into human induced pluripotent stem cell (iPSC)-derived 3D lung spheroids, specifically alveolar type II epithelial cells (iAT2) and basal cell (iBC) spheroids. Methods: Transfection of iAT2 spheroids within 3D Matrigel ‘in situ’, whole spheroids released from Matrigel or spheroids dissociated to single cells was explored via flow cytometry using a fluorescently labelled siRNA. Validation of the transfection method was performed in iAT2 and iBC spheroids using siRNA and miRNA mimics and measurement of specific target expression post-transfection. Results: Maximal delivery of siRNA was achieved in serum-free conditions in whole spheroids released from the Matrigel, followed by whole spheroids ‘in situ’. ‘In situ’ transfection of SFTPC-siRNA led to a 50% reduction in the SFTPC mRNA levels in iAT2 spheroids. Transfection of miR-29c mimic and miR-21 pre-miR into iAT2 and iBC spheroids, respectively, led to significant miRNA overexpression, together with a significant decrease in protein levels of the miR-29 target FOXO3a. Conclusions: This study demonstrates successful transfection of iPSC-derived lung spheroids without disruption of their 3D structure using a simple and feasible approach. Further development of these methods will facilitate functional studies in iPSC-derived spheroids utilizing small RNAs. Full article

Pulmonary arterial hypertension (PAH) is a rare condition characterized by high pulmonary artery pressure leading to right ventricular dysfunction and potential life-threatening consequences. It primarily affects the pre-capillary pulmonary vascular system. The exact pathophysiological mechanisms underlying PAH are not entirely known. Environmental factors; genetic predisposition; mitochondrial and microRNA dysfunction; and inflammatory, metabolic, and hormonal mechanisms may be involved. A central role is played by the dysfunction of the pulmonary vascular endothelium. This alteration is characterized by a reduction in vasodilatory and antiproliferative factors such as prostacyclin and nitric oxide and an increase in vasoconstrictive and mitogenic substances such as endothelin and thromboxane A2. Such imbalance leads to a progressive increase in pulmonary vascular resistance. The aim of the present review is to focus on the vascular endothelium and its role as a potential therapeutic target in PAH. Full article

Chronic inflammation driven by Cyclooxygenase-2 (COX-2) overexpression plays a key role in lung cancer (LC) progression, making it a critical therapeutic target. This study explores thymoquinone (TQ), a potent bioactive phytochemical derived from Nigella sativa, known for its anti-inflammatory and anti-cancer effects, focusing on its ability to suppress lipopolysaccharide (LPS)-induced COX-2 expression via microRNA hsa-miR-199a-3p modulation in LC cells. Using A549 and SHP-77 LC cells, we tested the effect of TQ under LPS stimulation and miRNA inhibition. Advanced techniques like TaqMan qPCR, luciferase reporter gene constructs, and anti-miRNA transfection confirmed that miR-199a-3p directly silences COX-2. Western blot and ELISA assays revealed that TQ dramatically reduces COX-2 protein and PGE2 levels by boosting miRNA-199a-3p. Importantly, TQ also blocked MAPK (p38, JNK, ERK) and NF-κB activation, even when miR-199a-3p was suppressed, proving its multi-targeted action beyond miRNA regulation. These findings reveal a novel anti-inflammatory mechanism, where TQ curbs COX-2-driven inflammation by enhancing miR-199a-3p, simultaneously shutting down pro-cancer MAPK/NF-κB signaling pathways. Given the strong link between chronic inflammation and LC aggressiveness, this study positions TQ as a promising therapeutic candidate, especially for inflammation-mediated lung cancer progression. Its dual ability to modulate miRNA and key signaling cascades makes it a compelling option for future LC treatment strategies. Full article

The Nile tilapia (Oreochromis niloticus), a key aquaculture species, displays marked sexual growth dimorphism, with males growing faster than females. This process is governed by intricate interactions between antagonistic regulators, including transcription factors, growth factors, and steroid hormones, operating through sex-specific developmental pathways. While circular RNAs (circRNAs) are known to modulate gene expression by sponging microRNAs (miRNAs), their role in teleost sex differentiation remains poorly understood. To address this gap, we profiled circRNA expression in tilapia gonads by constructing six circRNA libraries from testes and ovaries of 180 days after hatching (dah) fish, followed by high-throughput sequencing. We identified 6564 gonadal circRNAs distributed across all 22 linkage groups, including 226 differentially expressed circRNAs (DECs; 108 testis-biased, 118 ovary-biased). Functional enrichment analysis linked their host genes to critical pathways such as cAMP signaling, cell adhesion molecules, and—notably—sexual differentiation processes (e.g., estrogen signaling, oocyte meiosis, and steroid hormone biosynthesis). Furthermore, we deciphered competing endogenous RNA (ceRNA) networks, uncovering circRNA–miRNA–mRNA interactions targeting germ cell determinants, sex-specific transcription factors, and steroidogenic enzymes. This study provides the first systematic exploration of circRNA involvement in tilapia sex differentiation and gonadal differentiation, offering novel insights into the post-transcriptional regulation of sexual dimorphism. Our findings advance the understanding of circRNA biology in fish and establish a framework for future studies on aquaculture species with similar reproductive strategies. Full article

Background: Diabetic eye surface disease, including dry eye syndrome, corneal neuropathy, and diabetic retinopathy, is a common complication of diabetes. Tear fluid biomarkers may aid in early diagnosis and disease monitoring. The objective of this systematic review was to identify and evaluate tear fluid biomarkers in diabetic ocular surface disease according to PRISMA guidelines. Methods: PubMed, Scopus, and Embase databases were searched through June 2025. Eligible studies included clinical and observational studies measuring proteins, lipids, cytokines, trace elements, or nucleic acids in tear fluids in patients with diabetes. Results: The search identified 198 studies, and of those, 30 studies were included, comprising 14 original investigations with 871 participants (133 with type 1 diabetes, 453 with type 2 diabetes, 16 with pre-diabetes, and 269 healthy controls). The main biomarker categories were cytokines (IL-6, IL-8, TNF-α, and MMP-9), neuropeptides (substance P, NPY), proteins (IGFBP-3, progranulin), lipids, glycans, microRNAs, circRNAs, and trace elements. Conclusions: More than a dozen biomarkers in the tear fluid have been identified that may reflect diabetes-related changes in the ocular surface. Tear fluid analysis may be a valuable tool in personalizing the diagnosis and treatment of diabetic ocular surface diseases, but further studies are needed to confirm its clinical significance. Full article

Objective: This study aimed to elucidate the regulatory mechanisms of the long intergenic non-protein coding RNA 02381 (LINC02381)/microRNA-let-7g-5p (let-7g-5p)/thrombospondin 1 (THBS1) signaling axis in osteosarcoma (OS). Methods: The expression levels of LINC02381, let-7g-5p, and THBS1 were quantified in OS and adjacent normal tissues via reverse transcription quantitative polymerase chain reaction. Their correlations with clinicopathological features were analyzed. Expression patterns were further validated in OS cell lines (143B, U-2OS, Saos-2, MNNG-HOS, MG-63) and normal osteoblast cell line hFOB1.19. The molecular interaction between LINC02381 and let-7g-5p and the targeting relationship of let-7g-5p with THBS1 were verified via dual-luciferase reporter and RNA pull-down assays. Functional effects were assessed using cell counting kit-8, colony formation, Transwell migration, and xenograft tumor models. Results: Compared to adjacent normal tissues, LINC02381 and THBS1 were upregulated in OS tissues (fold change > 3.0, p < 0.001), while let-7g-5p was downregulated (fold change ≈ 0.038, p < 0.001). Similar expression trends were observed in U-2OS cells. Knockdown of LINC02381 or overexpression of let-7g-5p reduced cell proliferation, colony formation, migration, THBS1 expression, and tumor volume (p < 0.001). These inhibitory effects were partially reversed by let-7g-5p inhibitors, restoring cell viability and migration by approximately 70%. Mechanistically, LINC02381 functioned as a competing endogenous RNA (ceRNA), directly binding to let-7g-5p and mitigating its suppression of THBS1. Conclusions:LINC02381 promotes OA progression by acting as a ceRNA for let-7g-5p, thereby upregulating THBS1 expression. This signaling axis represents a potential therapeutic target for OS. Full article

Background/Objectives: The relationship between gut microbiota (GM) and microRNAs (miRs) related to lipid metabolism in individuals with metabolic syndrome (MetS) remains unclear. This pilot study examined the relationship between Bacteroidetes and Firmicutes abundance at the phylum level and the plasma levels of miR-122 and miR-370, both of which are associated with lipid metabolism, in Korean individuals with MetS and in healthy controls. We also evaluated the potential of these miRs as biomarkers for MetS. Methods: This study enrolled 7 individuals with MetS and 8 controls. The abundance of GM was analyzed by 16S rRNA amplicon sequencing. To evaluate the relationship between the dominant phyla in the 2 groups, the log ratio of Firmicutes to Bacteroidetes (F/B) was calculated using a centered log-ratio (CLR) transformation. The abundance of the 2 plasma miRs was also quantified by real-time quantitative PCR (RT-qPCR). Pearson’s and Spearman’s correlation analyses were then performed to evaluate the relationship between Bacteroidetes and Firmicutes abundance, the clinical parameters, and plasma levels of the 2 miRs. Additionally, the area under the curve (AUC) value of the receiver operating characteristic (ROC) curve was calculated to evaluate the potential of the 2 miRs as MetS biomarkers. Results: The 2 most abundant phyla were Bacteroidetes and Firmicutes. Bacteroidetes made up an average of 24.7% in the MetS group and 69.7% in the control group. Meanwhile, the average abundance of Firmicutes was 69.8% in the MetS group and 26.5% in the control group. The log F/B ratios in the MetS and control groups were 0.7 ± 0.5 and −0.4 ± 0.1 (p < 0.001), respectively. FDR analysis revealed significant correlations between Bacteroidetes abundance and BMI, DBP, FBG, total chol, insulin and HOMA-IR (FDR-adjusted p < 0.05), as well as between Firmicutes abundance and BMI, FBG, total chol, insulin and HOMA-IR (FDR-adjusted p < 0.05). Plasma levels of the 2 miRs differed significantly between the MetS and control groups: miR-122 (1.43 vs. 0.73; p = 0.0065) and miR-370 (1.39 vs. 0.83; p = 0.0089). The AUC values for miR-122 and miR-370 were 0.946 (p < 0.001) and 0.964 (p < 0.001), respectively. Pearson’s and Spearman’s correlation analyses revealed significant negative correlations between Bacteroidetes abundance and levels of miR-122 (p = 0.0048 and p = 0.0045, respectively) and miR-370 (p = 0.0003 and p < 0.0001, respectively), as well as significant positive correlations between Firmicutes abundance and levels of miR-122 (p = 0.0038 and p = 0.0027, respectively) and miR-370 (p = 0.0004 and p < 0.0001, respectively). However, as our exploratory findings were based on a small sample size, the high correlation results may partly reflect the separation between the MetS and control groups. Conclusions: Our exploratory findings suggest that the GM abundances of individuals with MetS may be significantly associated with plasma levels of miR-122 and miR-370, which are related to lipid metabolism. These miRs may therefore serve as potential MetS biomarkers. Full article

MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal roles in post-transcriptional gene regulation, influencing development, differentiation, and disease pathogenesis. Since their discovery in 1993, miRNAs have been recognized for their evolutionary conservation and pleiotropic effects, with the 2024 Nobel Prize underscoring their significance in post-transcriptional regulation via the RNA interference (RNAi) pathway. This review synthesizes the complete life cycle of miRNAs—from transcription and processing to function and decay—emphasizing regulatory mechanisms and their implications in human diseases, particularly cancer. We discuss how epitranscriptomic modifications influence miRNA biogenesis and activity, explore their nuclear and mitochondrial functions, and address emerging challenges in miRNA-based therapeutics, including the expanding small RNA landscape such as tRNA-derived small RNAs (tsRNAs), and Argonaute (AGO)-independent activities. Despite hurdles such as modest multi-target effects, off-target interactions, and delivery challenges, miRNAs remain promising as both biomarkers and therapeutic agents, underscoring the need for sustained research to bridge preclinical insights with clinical applications. Full article