MiRNA-146a-A Key Player in Immunity and Diseases

miR-146a is critical for orchestrating Mycobacterium fortuitum survival through anti-inflammatory and M2 macrophage responses in fish

The significance of microRNAs (miRNAs) in host response to non-tuberculoid mycobacteria like Mycobacterium fortuitum remains nascent. Using zebrafish kidney macrophages (ZFKM), we elucidate a novel function of miR-146a, orchestrated by the TLR-2-PI3K-NF-κB pathway, in M. fortuitum pathogenesis. We demonstrate that miR-146a facilitates anti-inflammatory response by targeting IRAK-1 and TRAF-6 in M. fortuitum-infected ZFKM. Moreover, miR-146a mitigates M1 macrophage activity by suppressing the iNOS-NO axis while enhancing M2-specific TGF-β mRNA expression and subsequent inhibition of M. fortuitum eradication. These findings collectively suggest that miR-146a diminishes macrophage-mediate M. fortuitum clearance. Our study provides novel insights into the intricate interplay between miRNAs and mycobacterial infections. We propose a mechanistic model wherein the TLR-2/NF-κB axis initiates miR-146a expression, which, in turn, suppresses irak-1 and traf-6, fostering the development of M2 macrophages. Consequently, this creates an anti-inflammatory environment conducive to M. fortuitumsurvival. Our findings provide novel insights into the intricate interplay between miRNAs and mycobacterial persistence, a concerning aspect of pathogenesis.

The miRNomics of antiretroviral therapy-induced obesity

Human immunodeficiency virus (HIV) is a retrovirus that incorporates its genetic material into the host's chromosome. The resulting diseases and related conditions constitute a global health problem as there are no treatments to eliminate HIV from an infected individual. However, the potent, complex, and active antiretroviral therapy (ART) strategies have been able to successfully inhibit HIV replication in patients. Unfortunately, obesity following ART is frequent among HIV-infected patients. The mechanism underlying ART-induced obesity is characterized based on expression of traditional markers such as genes and proteins. However, little is known about, yet another key component of molecular biology known as microRNAs (miRNAs). Micro-RNAs are ~ 22 base-long non-coding nucleotides capable of regulating more than 60% of all human protein-coding genes. The interest in miRNA molecules is increasing and their roles in HIV and obesity are beginning to be apparent. In this review, we provide an overview of HIV and its associated diseases, ART-induced obesity, and discuss the roles and plausible benefits of miRNAs in regulating obesity genes in HIV-infected patients. Understanding the roles of miRNAs in ART-induced obesity will aid in tracking the disease progression and designing beneficial therapeutic approaches.

A class of MicroRNAs as diagnostic biomarkers and therapeutic strategies in non-alcoholic fatty liver disease: A review

MicroRNAs (miRNAs), small and noncoding RNAs that regulate gene expression through hybridization to messenger RNA, play a crucial role in the prevention or progression of non-alcoholic fatty liver disease (NAFLD). There is an urgent demand for the improvement of diagnostic tools and effective pharmacotherapies for the treatment of NAFLD, which can advance to cirrhosis and liver cancer. MiRNAs act as regulatory factors and noninvasive diagnostic agents for NAFLD, enabling the staging of the disorder, prognosis, and identification of pharmaco-therapeutic targets. NAFLD causes alterations in the expression patterns of hepatocyte miRNAs, with some specific miRNAs related to the upgrade from NAFLD to non-alcoholic steatohepatitis (NASH). These miRNAs can activate certain signaling cascade and exacerbate or improve NAFLD, additionally, act as hepatocellular signals or second messengers that transmit information between the liver and other systems. This study provides a comprehensive review of the most important miRNAs and their involvement in the pathophysiology and cellular signaling pathways related to NAFLD.

Involvement of microRNA-146a-5p, but not -155-5p and -29b-5p, in left ventricular remodeling and dysfunction in spontaneously hypertensive rats

The contribution of microRNAs remains poorly understood in the context of hypertensive cardiac pathology. The role of miR-146a-5p, miR-155-5p, and miR-29b-5p in cardiac hypertrophy and dysfunction was investigated in spontaneously hypertensive rats (SHRs). Seven-month-old SHR (n = 7 male, n = 9 female) and normotensive Wistar Kyoto rats (WKY; n = 7 male, n = 9 female) underwent echocardiography. Plasma concentrations of inflammatory markers were measured by ELISA. Interstitial and perivascular fibrosis and percentage macrophage infiltration were determined by histology. Left ventricular (LV) mRNA expressions of cardiac remodeling markers and miRNA expressions were determined by RT-PCR. Circulating vascular cell adhesion molecule-1 (VCAM-1), macrophage infiltration, interstitial and perivascular fibrosis, relative wall thickness (RWT), early diastolic mitral inflow to tissue lengthening velocity at lateral mitral annulus (E/e'), and LV mRNA expression of NFKBIA and SOD2 were greater in SHRs. MidFS, e', and a' were lower in SHRs. Expression of LOX1, Col1a/Col3a ratio, circulating c-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), and RWT were greater in females. No difference in miR-29b-5p expression was noted. MiR-155-5p expression was lower in female and associated with stroke volume and absolute heart and LV masses. MiR-146a-5p expression was greater in SHRs and associated with systolic blood pressure (SBP), circulating VCAM-1, macrophage infiltration, interstitial fibrosis, normalized heart and LV masses, RWT, and a'. MiR-146a-5p was also associated with circulating VCAM-1 after adjustments for SBP. In addition, greater expression of miRNA-146a-5p reversed the relationship between circulating VCAM-1 and macrophage infiltration. Changes in the expression of miR-155-5p may be involved with a cardiac phenotype related to sexual dimorphism. Conversely, upregulation of miR-146a-5p expression may act as a countermechanism induced by myocardial inflammation in the setting of reactive fibrosis, established LV hypertrophy, and impaired diastolic function.NEW & NOTEWORTHY We investigated roles of microRNAs-146a-5p, -155-5p, and -29b-5p in development of cardiac hypertrophy and dysfunction in SHRs. We showed that miR-146a-5p expression was upregulated in SHRs and positively associated with indices of concentric LVH and diastolic dysfunction, potentially as countermechanism in response to myocardial inflammation, whereas miR-155-5p was expressed in a manner consistent with sexual dimorphism. Our data may offer novel insights on involvement of miRNAs in myocardial inflammation in hypertension-induced cardiac hypertrophy and dysfunction.

Liquid biopsies in cancer

Cancer ranks among the most lethal diseases worldwide. Tissue biopsy is currently the primary method for the diagnosis and biological analysis of various solid tumors. However, this method has some disadvantages related to insufficient tissue specimen collection and intratumoral heterogeneity. Liquid biopsy is a noninvasive approach for identifying cancer-related biomarkers in peripheral blood, which allows for repetitive sampling across multiple time points. In the field of liquid biopsy, representative biomarkers include circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and exosomes. Many studies have evaluated the prognostic and predictive roles of CTCs and ctDNA in various solid tumors. Although these studies have limitations, the results of most studies appear to consistently demonstrate the correlations of high CTC counts and ctDNA mutations with lower survival rates in cancer patients. Similarly, a reduction in CTC counts throughout therapy may be a potential prognostic indicator related to treatment response in advanced cancer patients. Moreover, the biochemical characteristics of CTCs and ctDNA can provide information about tumor biology as well as resistance mechanisms against targeted therapy. This review discusses the current clinical applications of liquid biopsy in cancer patients, emphasizing its possible utility in outcome prediction and treatment decision-making.

Glial Cells in Spinal Muscular Atrophy: Speculations on Non-Cell-Autonomous Mechanisms and Therapeutic Implications

Spinal muscular atrophy (SMA) is a neuromuscular disorder caused by homozygous deletions or mutations in the SMN1 gene, leading to progressive motor neuron degeneration. While SMA has been classically viewed as a motor neuron-autonomous disease, increasing evidence indicates a significant role of glial cells-astrocytes, microglia, oligodendrocytes, and Schwann cells-in the disease pathophysiology. Astrocytic dysfunction contributes to motor neuron vulnerability through impaired calcium homeostasis, disrupted synaptic integrity, and neurotrophic factor deficits. Microglia, through reactive gliosis and complement-mediated synaptic stripping, exacerbate neurodegeneration and neuroinflammation. Oligodendrocytes exhibit impaired differentiation and metabolic support, while Schwann cells display abnormalities in myelination, extracellular matrix composition, and neuromuscular junction maintenance, further compromising motor function. Dysregulation of pathways such as NF-κB, Notch, and JAK/STAT, alongside the upregulation of complement proteins and microRNAs, reinforces the non-cell-autonomous nature of SMA. Despite the advances in SMN-restorative therapies, they do not fully mitigate glial dysfunction. Targeting glial pathology, including modulation of reactive astrogliosis, microglial polarization, and myelination deficits, represents a critical avenue for therapeutic intervention. This review comprehensively examines the multifaceted roles of glial cells in SMA and highlights emerging glia-targeted strategies to enhance treatment efficacy and improve patient outcomes.

Significances of miRNAs for predicting sepsis mortality: a meta-analysis

Background

Sepsis is a life-threatening condition caused by a dysregulated immune response to infection and remains a major cause of mortality in intensive care units (ICUs). Recent studies have identified microRNAs (miRNAs), a class of small RNA molecules, as potential biomarkers for diagnosing and predicting outcomes in sepsis patients. However, the results of these studies have been inconsistent. This meta-analysis aims to comprehensively evaluate the diagnostic and prognostic value of miRNAs in predicting sepsis-related mortality.

Methods

A comprehensive literature search was performed across major databases, including PubMed, Cochrane Library, EMBASE, and CNKI, up to April 7, 2024. Data extraction and meta-analysis were conducted using Meta-disk 1.4 and STATA 15.1, employing both fixed- and random-effects models to ensure robust statistical analysis.

Results

A total of 55 studies met the inclusion criteria and were analyzed. The pooled sensitivity, specificity, and area under the summary receiver operating characteristic (SROC) curve for miRNA detection were calculated. The overall performance of total miRNA detection demonstrated a sensitivity of 0.76 (95% confidence interval [CI]: 0.74-0.77), a specificity of 0.72 (95% CI: 0.71-0.73), and an SROC value of 0.83. Subgroup analyses revealed that miR-133a-3p exhibited the highest diagnostic accuracy, with a pooled sensitivity of 0.83 (95% CI: 0.70-0.92), specificity of 0.79 (95% CI: 0.71-0.86), and an SROC value of 0.90. Additionally, other miRNAs, including miR-146a, miR-21, miR-210, miR-223-3p, miR-155, miR-25, miR-122, miR-125a, miR-125b, and miR-150, also demonstrated high SROC values (0.84 to 0.76).

Conclusion

This meta-analysis underscores the potential of several microRNAs (miRNAs) as reliable biomarkers for predicting sepsis mortality. Specifically, miR-133a-3p, miR-146a, miR-21, miR-210, miR-223-3p, miR-155, miR-25, miR-122, miR-125b, and miR-150 emerge as promising candidates for clinical applications in sepsis prognosis.

Non-coding RNAs: emerging biomarkers and therapeutic targets in cancer and inflammatory diseases

Non-coding RNAs (ncRNAs) have a significant role in gene regulation, especially in cancer and inflammatory diseases. ncRNAs, such as microRNA, long non-coding RNAs, and circular RNAs, alter the transcriptional, post-transcriptional, and epigenetic gene expression levels. These molecules act as biomarkers and possible therapeutic targets because aberrant ncRNA expression has been directly connected to tumor progression, metastasis, and response to therapy in cancer research. ncRNAs' interactions with multiple cellular pathways, including MAPK, Wnt, and PI3K/AKT/mTOR, impact cellular processes like proliferation, apoptosis, and immune responses. The potential of RNA-based therapeutics, such as anti-microRNA and microRNA mimics, to restore normal gene expression is being actively studied. Additionally, the tissue-specific expression patterns of ncRNAs offer unique opportunities for targeted therapy. Specificity, stability, and immune responses are obstacles to the therapeutic use of ncRNAs; however, novel strategies, such as modified oligonucleotides and targeted delivery systems, are being developed. ncRNA profiling may result in more individualized and successful treatments as precision medicine advances, improving patient outcomes and creating early diagnosis and monitoring opportunities. The current review aims to investigate the roles of ncRNAs as potential biomarkers and therapeutic targets in cancer and inflammatory diseases, focusing on their mechanisms in gene regulation and their implications for non-invasive diagnostics and targeted therapies. A comprehensive literature review was conducted using PubMed and Google Scholar, focusing on research published between 2014 and 2025. Studies were selected based on rigorous inclusion criteria, including peer-reviewed status and relevance to ncRNA roles in cancer and inflammatory diseases. Non-English, non-peer-reviewed, and inconclusive studies were excluded. This approach ensures that the findings presented are based on high-quality and relevant sources.

Oxidative Stress by H2O2 as a Potential Inductor in the Switch from Commensal to Pathogen in Oncogenic Bacterium Fusobacterium nucleatum

BACKGROUND

Fusobacterium nucleatum is a pathobiont that plays a dual role as both a commensal and a pathogen. The oral cavity typically harbors this anaerobic, Gram-negative bacterium. At the same time, it is closely linked to colorectal cancer due to its potential involvement in tumor progression and resistance to chemotherapy. The mechanism by which it transforms from a commensal to a pathogen remains unknown. For this reason, we investigated the role of oxidative status as an initiatory factor in changing the bacterium's pathogenicity profile.

METHODS

A clinical strain of F. nucleatum subsp. animalis biofilm was exposed to different oxidative stress levels through varying subinhibitory amounts of H2O2. Subsequently, we investigated the bacterium's behavior in vitro by infecting the HT-29 cell line. We evaluated bacterial colonization, volatile sulfur compounds production, and the infected cell's oxidative status by analyzing HMOX1, pri-miRNA 155, and 146a gene expression.

RESULTS

The bacterial colonization rate, dimethyl sulfide production, and pri-miRNA 155 levels all increased when stressed bacteria were used, suggesting a predominant pathogenic function of these strains.

CONCLUSIONS

The response of F. nucleatum to different oxidative conditions could potentially explain the increase in its pathogenic traits and the existence of environmental factors that may trigger the bacterium's pathogenicity and virulence.

Unleashing the potential of extracellular vesicles for ulcerative colitis and Crohn's disease therapy

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Non-coding RNAs as mediators of epithelial to mesenchymal transition in metastatic colorectal cancers

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality globally, necessitating the development of innovative treatment strategies. Recent research has underscored the significant role of non-coding RNAs (ncRNAs) in CRC pathogenesis, offering new avenues for diagnosis and therapy. In this review, we delve into the intricate roles of various ncRNAs, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in CRC progression, epithelial-mesenchymal transition (EMT), metastasis, and drug resistance. We highlight the interaction of these ncRNAs with and regulation of key signaling pathways, such as Wnt/β-catenin, Notch, JAK-STAT, EGFR, and TGF-β, and the functional relevance of these interactions in CRC progression. Additionally, the review highlights the emerging applications of nanotechnology in enhancing the delivery and efficacy of ncRNA-based therapeutics, which could address existing challenges related to specificity and side effects. Future research directions, including advanced diagnostic tools, targeted therapeutics, strategies to overcome drug resistance, and the integration of personalized medicine approaches are discussed. Integrating nanotechnology with a deeper understanding of CRC biology offers the potential for more effective, targeted, and personalized strategies, though further research is essential to validate these approaches.

Fish MicroRNA Responses to Thermal Stress: Insights and Implications for Aquaculture and Conservation Amid Global Warming

In the context of global warming, heat tolerance is becoming a crucial physiological trait influencing fish species' distribution and survival. While our understanding of fish heat tolerance and stress has expanded from behavioral studies to transcriptomic analyses, knowledge at the transcriptomic level is still limited. Recently, the highly conserved microRNAs (miRNAs) have provided new insights into the molecular mechanisms of heat stress in fish. This review systematically examines current research across three main reference databases to elucidate the universal responses and mechanisms of fish miRNAs under heat stress. Our initial screening of 569 articles identified 13 target papers for comprehensive analysis. Among these, at least 214 differentially expressed miRNAs (DEMs) were found, with 15 DEMs appearing in at least two studies (12 were upregulated and 13 were downregulated). The 15 recurrent DEMs were analyzed using DIANA mirPath v.3 and the microT-CDS v5.0 database to identify potential target genes. The results suggest that multiple miRNAs target various genes, forming a complex network that regulates glucose and energy metabolism, maintains homeostasis, and modulates inflammation and immune responses. Significantly, miR-1, miR-122, let-7a, and miR-30b were consistently differentially expressed in multiple studies, indicating their potential relevance in heat stress responses. However, these miRNAs should not be considered definitive biomarkers without further validation. Future research should focus on experimentally confirming their regulatory roles through functional assays, conducting transcriptomic comparisons across different species, and performing target validation studies. These miRNAs, conserved across species, could be valuable for monitoring wild fish health, enhancing aquaculture breeding, and guiding conservation strategies. However, the specific regulatory mechanisms of these miRNAs need clarification to confirm their reliability as biomarkers for thermal stress.

Molecular Mechanisms of Immune Regulation: A Review

BACKGROUND

The immune system must carefully balance fighting pathogens with minimization of inflammation and avoidance of autoimmune responses. Over the past ten years, researchers have extensively studied the mechanisms regulating this delicate balance. Comprehending these mechanisms is essential for developing treatments for inflammatory conditions.

AIM

This review aims to synthesize knowledge of immunoregulatory processes published from 2014-2024 and to highlight discoveries that provide fresh perspectives on this complex balance.

METHODS

The keywords "molecular mechanisms", "immune regulation", "immune signaling pathways", and "immune homeostasis" were used to search PubMed for articles published between 2014 and 2024, with a preference for articles published in the past three years.

RESULTS

Recent research has pinpointed the impact of factors such as cytokine signaling, T-cell regulation, epigenetic regulation, and immunometabolism on immune function.

DISCUSSION

New research highlights the intricate interactions between the immune system and other molecular elements. A key area of interest is the impact of non-coding RNAs and metabolic pathways on the regulation of immune responses.

CONCLUSIONS

Exploring the mechanisms by which the immune system is regulated will provide new avenues for developing treatments to address autoimmune and inflammatory conditions.

New Insights in Natural Bioactive Compounds for Periodontal Disease: Advanced Molecular Mechanisms and Therapeutic Potential

Periodontal disease is a chronic inflammatory condition that destroys the tooth-supporting structures due to the host's immune response to microbial biofilms. Traditional periodontal treatments, such as scaling and root planing, pharmacological interventions, and surgical procedures, have significant limitations, including difficulty accessing deep periodontal pockets, biofilm recolonization, and the development of antibiotic resistance. In light of these challenges, natural bioactive compounds derived from plants, herbs, and other natural sources offer a promising alternative due to their anti-inflammatory, antioxidant, antimicrobial, and tissue-regenerative properties. This review focuses on the molecular mechanisms through which bioactive compounds, such as curcumin, resveratrol, epigallocatechin gallate (EGCG), baicalin, carvacrol, berberine, essential oils, and Gum Arabic, exert therapeutic effects in periodontal disease. Bioactive compounds inhibit critical inflammatory pathways like NF-κB, JAK/STAT, and MAPK while activating protective pathways such as Nrf2/ARE, reducing cytokine production and oxidative stress. They also inhibit the activity of matrix metalloproteinases (MMPs), preventing tissue degradation and promoting healing. In addition, these compounds have demonstrated the potential to disrupt bacterial biofilms by interfering with quorum sensing, targeting bacterial cell membranes, and enhancing antibiotic efficacy.Bioactive compounds also modulate the immune system by shifting the balance from pro-inflammatory to anti-inflammatory responses and promoting efferocytosis, which helps resolve inflammation and supports tissue regeneration. However, despite the promising potential of these compounds, challenges related to their poor bioavailability, stability in the oral cavity, and the absence of large-scale clinical trials need to be addressed. Future strategies should prioritize the development of advanced delivery systems like nanoparticles and hydrogels to enhance bioavailability and sustain release, alongside long-term studies to assess the effects of these compounds in human populations. Furthermore, combining bioactive compounds with traditional treatments could provide synergistic benefits in managing periodontal disease. This review aims to explore the therapeutic potential of natural bioactive compounds in managing periodontal disease, emphasizing their molecular mechanisms of action and offering insights into their integration with conventional therapies for a more comprehensive approach to periodontal health.

Can miRNAs in MSCs-EVs Offer a Potential Treatment for Hypoxic-ischemic Encephalopathy?

Neonatal hypoxic-ischemic encephalopathy (HIE) is a critical condition resulting from impaired oxygen and blood flow to the brain during birth, leading to neuroinflammation, neuronal apoptosis, and long-term neurological deficits. Despite the use of therapeutic hypothermia, current treatments remain inadequate in fully preventing brain damage. Recent advances in mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) offer a novel, cell-free therapeutic approach, as these EVs can cross the blood-brain barrier (BBB) and deliver functional microRNAs (miRNAs) to modulate key pathways involved in inflammation and neuroprotection. This review examines how specific miRNAs encapsulated in MSC-EVs-including miR-21, miR-124, miR-146, and the miR-17-92 cluster-target the complex inflammatory responses that drive HIE pathology. By modulating pathways such as NF-κB, STAT3, and PI3K/Akt, these miRNAs influence neuroinflammatory processes, reduce neuronal apoptosis, and promote tissue repair. The aim is to assess the therapeutic potential of miRNA-loaded MSC-EVs in mitigating inflammation and neuronal damage, thus addressing the limitations of current therapies like therapeutic hypothermia.

The Molecular Basis of Asthma Exacerbations Triggered by Viral Infections: The Role of Specific miRNAs

Viral respiratory infections are a significant clinical problem among the pediatric population and are one of the leading causes of hospitalization. Most often, upper respiratory tract infections are self-limiting. Still, those that involve the lower respiratory tract are usually associated with asthma exacerbations, leading to worsening or even the initiation of the disease. A key role in regulating the immune response and inflammation during viral infections and their impact on the progression of asthma has been demonstrated for miRNA molecules (microRNA). Their interaction with mRNA (messenger RNA) regulates gene expression in innate and acquired immune responses, making them valuable biomarkers for diagnostics, monitoring, and predicting asthma exacerbations. The following paper presents changes in the expression of miRNAs during the five most common viral infections causing asthma worsening, with particular emphasis on the pediatric population. In addition, we describe the molecular mechanisms by which miRNAs influence the pathogenesis of viral infection, immune responses, and asthma exacerbations. These molecules represent promising targets for future innovative therapeutic strategies, paving the way for developing personalized medicine for patients with viral-induced asthma exacerbations.

The Role of Bovine Milk-Derived Exosomes in Human Health and Disease

Bovine milk is widely recognized as one of the most valuable sources of nutrients such as proteins, fats, vitamins, and minerals that support the development and health of the body. In recent years, there has been increasing scientific interest in exosomes, the small membrane-bound vesicles found in milk. Through their content (e.g., microRNA), exosomes can influence gene expression and modulate key signaling pathways within target cells. Results from in vitro and in vivo studies have shown that bovine milk-derived exosomes can alleviate intestinal inflammation by regulating signaling pathways and positively influencing the composition of the gut microbiota. They also improve cognitive function and support nervous system regeneration. In addition, exosomes promote bone health by stimulating osteoblast formation and inhibiting bone resorption, helping to prevent osteoporosis. Studies have shown that exosomes have beneficial effects on skin health by promoting collagen production, protecting cells from oxidative stress, and delaying the ageing process. Bovine milk-derived exosomes are a promising tool for the treatment and prevention of a variety of diseases, particularly those related to inflammation and tissue regeneration. Although these results are promising, further studies are needed to fully understand the mechanisms of action and the potential clinical application of milk exosomes in the prevention and treatment of different diseases.

Epigenetic biomarkers in Alzheimer's disease: Diagnostic and prognostic relevance

Alzheimer's disease (AD) is a leading cause of cognitive decline in the aging population, presenting a critical need for early diagnosis and effective prognostic tools. Epigenetic modifications, including DNA methylation, histone modifications, and non-coding RNAs, have emerged as promising biomarkers for AD due to their roles in regulating gene expression and potential for reversibility. This review examines the current landscape of epigenetic biomarkers in AD, emphasizing their diagnostic and prognostic relevance. DNA methylation patterns in genes such as APP, PSEN1, and PSEN2 are highlighted for their strong associations with AD pathology. Alterations in DNA methylation at specific CpG sites have been consistently observed in AD patients, suggesting their utility in early detection. Histone modifications, such as acetylation and methylation, also play a crucial role in chromatin remodelling and gene expression regulation in AD. Dysregulated histone acetylation and methylation have been linked to AD progression, making these modifications valuable biomarkers. Non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), further contribute to the epigenetic regulation in AD. miRNAs can modulate gene expression post-transcriptionally and have been found in altered levels in AD, while lncRNAs can influence chromatin structure and gene expression. The presence of these non-coding RNAs in biofluids like blood and cerebrospinal fluid positions them as accessible and minimally invasive biomarkers. Technological advancements in detecting and quantifying epigenetic modifications have propelled the field forward. Techniques such as next-generation sequencing, bisulfite sequencing, and chromatin immunoprecipitation assays offer high sensitivity and specificity, enabling the detailed analysis of epigenetic changes in clinical samples. These tools are instrumental in translating epigenetic research into clinical practice. This review underscores the potential of epigenetic biomarkers to enhance the early diagnosis and prognosis of AD, paving the way for personalized therapeutic strategies and improved patient outcomes. The integration of these biomarkers into clinical workflows promises to revolutionize AD management, offering hope for better disease monitoring and intervention.

The Yin and Yang of Microglia-Derived Extracellular Vesicles in CNS Injury and Diseases

Microglia, the resident immune cells of the central nervous system (CNS), play a crucial role in maintaining neural homeostasis but can also contribute to disease and injury when this state is disrupted or conversely play a pivotal role in neurorepair. One way that microglia exert their effects is through the secretion of small vesicles, microglia-derived exosomes (MGEVs). Exosomes facilitate intercellular communication through transported cargoes of proteins, lipids, RNA, and other bioactive molecules that can alter the behavior of the cells that internalize them. Under normal physiological conditions, MGEVs are essential to homeostasis, whereas the dysregulation of their production and/or alterations in their cargoes have been implicated in the pathogenesis of numerous neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), spinal cord injury (SCI), and traumatic brain injury (TBI). In contrast, MGEVs may also offer therapeutic potential by reversing inflammation or being amenable to engineering for the delivery of beneficial biologics or drugs. The effects of MGEVs are determined by the phenotypic state of the parent microglia. Exosomes from anti-inflammatory or pro-regenerative microglia support neurorepair and cell survival by delivering neurotrophic factors, anti-inflammatory mediators, and molecular chaperones. Further, MGEVs can also deliver components like mitochondrial DNA (mtDNA) and proteins to damaged neurons to enhance cellular metabolism and resilience. MGEVs derived from pro-inflammatory microglia can have detrimental effects on neural health. Their cargo often contains pro-inflammatory cytokines, molecules involved in oxidative stress, and neurotoxic proteins, which can exacerbate neuroinflammation, contribute to neuronal damage, and impair synaptic function, hindering neurorepair processes. The role of MGEVs in neurodegeneration and injury-whether beneficial or harmful-largely depends on how they modulate inflammation through the pro- and anti-inflammatory factors in their cargo, including cytokines and microRNAs. In addition, through the propagation of pathological proteins, such as amyloid-beta and alpha-synuclein, MGEVs can also contribute to disease progression in disorders such as AD and PD, or by the transfer of apoptotic or necrotic factors, they can induce neuron toxicity or trigger glial scarring during neurological injury. In this review, we have provided a comprehensive and up-to-date understanding of the molecular mechanisms underlying the multifaceted role of MGEVs in neurological injury and disease. In particular, the role that specific exosome cargoes play in various pathological conditions, either in disease progression or recovery, will be discussed. The therapeutic potential of MGEVs has been highlighted including potential engineering methodologies that have been employed to alter their cargoes or cell-selective targeting. Understanding the factors that influence the balance between beneficial and detrimental exosome signaling in the CNS is crucial for developing new therapeutic strategies for neurodegenerative diseases and neurotrauma.

Unveiling the therapeutic potential of miR-146a: Targeting innate inflammation in atherosclerosis

Atherosclerosis is the foremost vascular disease, precipitating debilitating complications. Although therapeutic strategies have historically focused on reducing cholesterol deposition, recent insights emphasize the pivotal role of inflammation. Innate inflammation significantly contributes to plaque instability and rupture, underscoring the need for intervention across all disease stages. Numerous studies have highlighted the therapeutic potential of targeting innate immune pathways in atherosclerosis, revealing significant advancements in understanding the molecular mechanisms underlying inflammatory processes within arterial lesions. Notably, research has demonstrated that the modulation of microRNA-146a (miR-146a) expression impacts innate inflammation, effectively halts atherosclerosis progression, and enhances plaque stability by targeting interleukin-1 receptor-associated kinase (IRAK) and activating TNF receptor-associated factor 6 (TRAF6), a signalling pathway involving toll-like receptors (TLRs). Understanding the intricate mechanisms involved is crucial. This study provides a comprehensive analysis of the evidence and underlying mechanisms through which miR-146a exerts its effects. Integrating these findings into clinical practice may herald a transformative era in managing atherosclerotic cardiovascular disease.

MiR-146a (rs2910164) Gene Polymorphism and Its Impact on Circulating MiR-146a Levels in Patients with Inflammatory Bowel Diseases

MicroRNA-146a (miR-146a) has been involved in the pathophysiology of inflammatory bowel disease (IBD). However, the precise processes are still not entirely understood. Contradictory studies suggest that miR-146a expression could be influenced by the miR-146a rs2910164 C > G polymorphism. This case-control study aimed to investigate the association of miR-146a rs2910164 C > G gene polymorphism and its impact on circulating miR-146a expression levels in Egyptian IBD patients. We included 40 IBD patients and 30 matched healthy controls. Genotyping of miR-146a rs2910164 polymorphism and assessment of miR-146a expression level were done using quantitative real-time PCR in all participants. MiR-146a rs2910164 GG genotype and the G allele were reported in 47% and 70% of the IBD patient group, respectively. And they were associated with increased IBD risk. All the IBD patients with the CC genotype (100%) and most of those with the CG genotype (66.67%) had an inactive disease, while most IBD patients with the GG genotype (73.68%) had an active disease. The miR-146a expression level was the highest with the CC genotype and the lowest with the GG genotype. Also, miR-146a expression level decreased significantly in IBD patients than controls and with disease activity. Combined detection of fecal calprotectin with miR-146a expression level improved the diagnostic sensitivity and the negative predictive value in differentiating IBD patients with active disease from those inactive. Our study identified a strong association of miR-146a rs2910164 GG genotype and G allele with IBD-increased susceptibility and activity in the Egyptian population. The miR-146a rs2910164 polymorphism can reduce miR-146a expression levels in these patients as well. Further research on a larger sample size and different ethnic populations can be the key to progress in establishing this genetic association.

The role of extracellular vesicles in cancer

Extracellular vesicles (EVs), which include small EVs such as exosomes, play a critical role in intercellular communication and are produced by both cancer and non-cancer cells. Several studies have shown that cancer cells exploit various strategies to regulate the biogenesis, composition, and functions of EVs primarily to promote cancer progression. Given that exosomes originate from major sorting hubs at the limiting membrane of endosomes, they are central to a signaling network that connects external stimuli with intrinsic tumor cell features. Exosomes contain diverse repertoires of molecular cargos, such as proteins, lipids, and nucleic acids, which determine their heterogeneity and functional properties in cancer progression. Therefore, targeting exosome biogenesis will enhance our understanding of tumorigenesis and also promote the discovery of novel approaches for cancer therapy. In this chapter we summarize the machinery of exosome biogenesis and the local, distant, and systemic effects of exosomes released by cancer cells. Furthermore, we explore how these exosomes regulate the anti-tumor immune response and epigenetic mechanisms to sustain cancer progression and their implications in cancer prevention and treatment.

Indirect influence of microRNA-146a on the association of IL-6 and TNF-α genetic polymorphisms with the increased risk of hip osteoarthritis

Primary osteoarthritis (POA) is a complex hereditary disease that involves the interplay between genetics and epigenetics. MicroRNA molecules play important roles in epigenetic mechanisms. MicroRNA-146a (miR-146a) is a negative regulator of the immune response in osteoarthritis (OA). So, variations in the miR-146a gene could affect OA risk. The aim of this study was to investigate the relationships between single nucleotide polymorphisms (SNPs) in the miR-146a, interleukin-6 (IL-6), Toll-like receptor 10 (TLR10), and tumor necrosis factor-alpha (TNFA) genes and the risk for development of advanced-stage primary hip osteoarthritis (PHOA) and primary knee osteoarthritis (PKOA) in the Croatian population. A total of 609 POA patients and 656 healthy donors were genotyped for SNPs in the miR-146a (rs2910164, G>C). Since we used same patients and controls as two studies before us, we already had information about IL-6 (rs1800795, C>G), TLR10 (rs11096957, C>T), and TNFA (rs1800629, C>T) genotypes of our subjects. None of the differences were statistically significant comparing either allelic or genotypic frequencies of miR-146a SNP rs2910164 (G>C) between the PHOA and PKOA patients and controls. However, we found a significant association with risk to PHOA for the combination of genotypes (stratified miR-146a genotype with the IL-6, and stratified miR-146a genotype with the TNFA). In a multifactorial disease such as POA, we have shown the indirect relevance of a second modifying factor (miR-146a), which apparently contributes to the overall risk of PHOA. There was no risk association with the PKOA, indicating that these two localities (hip and knee) might have different risk-modifying factors.

Protective effect of hesperidin on malathion-induced ovarian toxicity in mice: The role of miRNAs, inflammation, and apoptosis

Malathion, a widely used organophosphate, is known for its relatively low toxicity and extensive application. However, it has been found to act as a female reproductive toxicant by causing oxidative stress, apoptosis, autophagy, and hormonal imbalances. Hesperidin, a flavonoid belonging to the flavanone class, exhibits various beneficial properties such as antioxidant and anti-inflammatory effects, which can potentially counteract harmful effects. The objective of this study was to examine how hesperidin and malathion impact the expression of miRNAs and genes linked to apoptosis and inflammation. Balb/c mice (n = 40) were divided into four groups: hesperidin (20 mg/kg), malathion (3 mg/kg), hesperidin+malathion, and control. After a 35-day intraperitoneal treatment, the mice were sacrificed. The left ovaries were used for analyzing the expression of miRNA-146a-5p, miRNA-129-3p, miRNA-96-5p, NF-κB, Bax, and Bcl-2 through RT-qPCR, as well as the levels of several cytokines using the ELISA method. The right ovaries were examined through histological and immunohistochemical techniques using H&E and NF-κB staining. Malathion exposure led to an increased Bax/Bcl-2 ratio, upregulated expression of Bax and NF-κB, elevated levels of IFN-γ, IL-2, and IL-6, enhanced expression of miRNA-146a-5p, decreased expression of miRNA-129-3p and miRNA-96-5p, and reduced levels of IL-4 and IL-10. Additionally, malathion-exposed ovaries exhibited structural abnormalities and disrupted architecture, accompanied by heightened NF-κB immunoreactivity. Conversely, treatment with hesperidin showed its capacity to counteract the detrimental consequences of malathion on the ovaries by alleviating or reversing these changes. In conclusion, hesperidin showed protective effects against malathion-induced ovarian toxicity by modulating cytokine production, apoptosis, inflammation, and miRNA expression.

Analysis of IL-17A, IL-17F, and miR-146a-5p Prior to Transplantation and Their Role in Kidney Transplant Recipients

Background/Objectives: The balance between regulatory and Th17 cells plays an important role in maintaining the immune tolerance after kidney transplantation (KTx) which is essential for transplantation success, defined as a long graft survival and an absence of organ rejection. The present study aimed to assess whether the pretransplant characteristics of IL-17A and IL-17F, their receptors, as well as miR-146a-5p, an miRNA associated with IL-17A/F regulation, can predict KTx outcomes. Methods: A group of 108 pre-KTx dialysis patients and 125 healthy controls were investigated for single nucleotide substitutions within genes coding for IL-17A, IL-17F, their IL-17RA/RC receptors, and miR-146a-5p. Genotyping was performed using LightSNiP assays. In addition, IL17-A/F serum concentrations were determined using ELISA while miR-146a-5p expression was analyzed by RT-PCR. Results: The IL-17F (rs763780) G allele prevailed in KTx recipients as compared to healthy individuals (OR = 23.59, p < 0.0001) and was associated with a higher IL-17F serum level (p = 0.0381) prior to transplantation. Higher miR-146a-5p expression before KTx was more frequently detected in recipients with an increased IL-17A serum concentration (p = 0.0177). Moreover, IL-17A (rs2275913) GG homozygosity was found to be associated with an increased incidence of deaths before KTx (OR = 4.17, p = 0.0307). T-cell or acute rejection episodes were more frequently observed among patients with the C allele of miR-146a-5p (rs2910164) (OR = 5.38, p = 0.0531). IL17-RA/-RC genetic variants (p < 0.05) seem to be associated with eGFR values. Conclusions: These results imply that IL-17F (rs763780) polymorphism is associated with the serum level of this cytokine and may be related to the risk of renal disease and transplant rejection together with miR-146a-5p (rs2910164), while the IL-17A (rs2275913) genotype may affect patients' survival before KTx.

A Comparative Analysis of MicroRNA Expression in Mild, Moderate, and Severe COVID-19: Insights from Urine, Serum, and Nasopharyngeal Samples

COVID-19, caused by the SARS-CoV-2 virus, manifests with a wide range of clinical symptoms that vary from mild respiratory issues to severe respiratory distress. To effectively manage and predict the outcomes of the disease, it is important to understand the molecular mechanisms underlying its severity. This study focuses on analyzing and comparing the expression patterns of microRNAs (miRNAs) in serum, urine, and nasopharyngeal samples from patients with mild, moderate, and severe COVID-19. The aim is to identify potential associations with disease progression and discover suitable markers for diagnosis and prognosis. Our findings indicate the consistent upregulation of miR-21, miR-146a, and miR-155 in urine, serum, and nasopharyngeal samples from patients with mild COVID-19. In moderate cases, there were more significant changes in miRNA expression compared to mild cases. Specifically, miR-let-7 demonstrated upregulation, while miR-146b exhibited downregulation. The most notable alterations in miRNA expression profiles were observed in severe COVID-19 cases, with a significant upregulation of miR-223. Moreover, our analysis using Receiver-operating characteristic (ROC) curves demonstrated that miR-155, miR-let-7, and miR-223 exhibited high sensitivity and specificity, suggesting their potential as biomarkers for distinguishing COVID-19 patients from healthy individuals. Overall, this comparative analysis revealed distinct patterns in miRNA expression. The overlapping expression patterns of miRNAs in urine, serum, and nasopharyngeal samples suggest their potential utility in discriminating disease status.