Search Results (5,620)

Alkyladenine DNA glycosylase (AAG) is a critical enzyme in the base excision repair (BER) pathway, responsible for removing a broad spectrum of alkylated DNA lesions. While AAG maintains genomic stability, dysregulated activity has been implicated in cancer development, drug resistance, and neurodegenerative diseases. This review synthesizes the current knowledge on AAG’s structure, catalytic mechanism, and polymorphic variants, highlighting their potential roles in disease pathogenesis. A comprehensive bioinformatics analysis of over 370 AAG single-nucleotide polymorphisms (SNPs) is presented, identifying ~40% as high-risk variants likely to impair enzymatic function. Notably, 151 SNPs were predicted to be damaging by multiple algorithms, including substitutions at catalytic residues and non-conserved sites with unknown functional consequences. Analysis of cancer databases (COSMIC, cBioPortal, NCBI) revealed 93 tumor-associated AAG variants, with 18 classified as high-impact mutations. This work underscores the need for mechanistic studies of AAG variants using structural biology, cellular models, and clinical correlation analyses. Deciphering AAG’s polymorphic landscape may unlock personalized strategies for cancer prevention and treatment. Full article

Head and neck squamous cell carcinoma (HNSCC) is a highly aggressive malignancy characterized by complex interactions within the tumor microenvironment (TME) that facilitate immune evasion and tumor progression. The TME consists of diverse cellular components, including cancer-associated fibroblasts, immune and endothelial cells, and extracellular matrix elements, that collectively modulate tumor growth, metastasis, and resistance to therapy. Immune evasion in HNSCC is orchestrated through multiple mechanisms, including the suppression of cytotoxic T lymphocytes, recruitment of immunosuppressive cells, such as regulatory T and myeloid-derived suppressor cells, and upregulation of immune checkpoint molecules (e.g., PD-1/PD-L1 and CTLA-4). Natural killer (NK) cells, which play a crucial role in anti-tumor immunity, are often dysfunctional within the HNSCC TME due to inhibitory signaling and metabolic constraints. Additionally, endothelial cells contribute to tumor angiogenesis and immune suppression, further exacerbating disease progression. Recent advancements in immunotherapy, particularly immune checkpoint inhibitors and NK cell-based strategies, have shown promise in restoring anti-tumor immunity. Moreover, TP53 mutations, frequently observed in HNSCC, influence tumor behavior and therapeutic responses, highlighting the need for personalized treatment approaches. This review provides a comprehensive analysis of the molecular and cellular mechanisms governing immune evasion in HNSCC with a focus on novel therapeutic strategies aimed at improving patient outcomes. Full article

Pediatric asthma is a multifactorial and heterogeneous disease determined by the dynamic interplay of genetic susceptibility, environmental exposures, and immune dysregulation. Recent advances have highlighted the pivotal role of epigenetic mechanisms, in particular, DNA methylation, histone modifications, and non-coding RNAs, in the regulation of inflammatory pathways contributing to asthma phenotypes and endotypes. This review examines the role of respiratory viruses such as respiratory syncytial virus (RSV), rhinovirus (RV), and other bacterial and fungal infections that are mediators of infection-induced epithelial inflammation that drive epithelial homeostatic imbalance and induce persistent epigenetic alterations. These alterations lead to immune dysregulation, remodeling of the airways, and resistance to corticosteroids. A focused analysis of T2-high and T2-low asthma endotypes highlights unique epigenetic landscapes directing cytokines and cellular recruitment and thereby supports phenotype-specific aspects of disease pathogenesis. Additionally, this review also considers the role of miRNAs in the control of post-transcriptional networks that are pivotal in asthma exacerbation and the severity of the disease. We discuss novel and emerging epigenetic therapies, such as DNA methyltransferase inhibitors, histone deacetylase inhibitors, miRNA-based treatments, and immunomodulatory probiotics, that are in preclinical or early clinical development and may support precision medicine in asthma. Collectively, the current findings highlight the translational relevance of including pathogen-related biomarkers and epigenomic data for stratifying pediatric asthma patients and for the personalization of therapeutic regimens. Epigenetic dysregulation has emerged as a novel and potentially transformative approach for mitigating chronic inflammation and long-term morbidity in children with asthma. Full article

Recent studies have demonstrated that the development and progression of hypertensive kidney injury comprise not only elevated systemic blood pressure but also a complex interplay of cellular, molecular, and genetic mechanisms. In this report, we outline the key emerging pathways—ranging from dysregulated renin–angiotensin system signaling, oxidative stress, immune-mediated inflammation, and metabolic abnormalities to epigenetic alterations and genetic susceptibilities—that contribute to kidney damage in hypertensive conditions. In addition, we also discuss precision medicine approaches like biomarker-directed therapies, pharmacologically targeted therapies, and device-based innovations for modulating these pathways. This integrative review emphasizes the application of omics technologies and genetically guided interventions to better stratify patients and offer personalized care for hypertensive kidney disease. Full article

Ferroptosis is a distinct form of regulated cell death driven by iron-dependent lipid peroxidation participating in various diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a central regulator of cellular redox homeostasis and a key determinant of ferroptosis resistance. Nrf2 activates the expression of downstream antioxidant genes to protect cells from oxidative stress and ferroptosis. Consequently, precise regulation of Nrf2 expression is crucial. Recent studies have revealed that complex epigenetic mechanisms involving DNA methylation, histone modifications, and non-coding RNA networks regulate Nrf2 expression. DNA methylation usually suppresses while histone acetylation promotes Nrf2 expression. The influences of histone methylation on NFE2L2 are site- and methylation degree-dependent. m6A modification stabilizes NFE2L2 mRNA to promote Nrf2 expression and thereby inhibit ferroptosis. This article summarizes current understanding of the epigenetic mechanisms controlling Nrf2 expression and Nrf2-mediated ferroptosis pathways and their implications in disease models. The challenges associated with the epigenetic regulation of Nrf2 and future research directions are also discussed. A comprehensive understanding of this regulatory interplay could open new avenues for intervention in ferroptosis-related diseases by fine-tuning cellular redox balance through the epigenetic modulation of Nrf2. Full article

Chronic low-grade inflammation is a hallmark of both metabolic and neurodegenerative diseases. In recent years, several studies have highlighted the pivotal role of systemic metabolic dysfunction, particularly insulin resistance, in shaping neuroinflammatory processes and contributing to impaired cognitive performance. Among metabolic disorders, type 2 diabetes mellitus has emerged as a major risk factor for the development of age-related neurodegenerative conditions, suggesting a complex and bidirectional crosstalk between peripheral metabolic imbalance and central nervous system function. This review aims to explore the cellular and molecular mechanisms underlying the interaction between metabolic dysregulation and brain inflammation. By integrating current findings from endocrinology, immunology, and neuroscience, this work provides a comprehensive overview of how chronic metabolic inflammation may contribute to the onset and progression of neurodegenerative conditions. This interdisciplinary approach could offer novel insights into potential therapeutic strategies targeting both metabolic and neuroinflammatory pathways. Full article

Fyn is widely involved in diverse cellular physiological processes, including cell growth and survival, and has been implicated in the regulation of energy metabolism and the pathogenesis of diabetes mellitus through multiple pathways. Fyn plays a role in increasing fat accumulation and promoting insulin resistance, and it also contributes to the development of diabetic complications such as diabetic kidney disease and diabetic retinopathy. The primary mechanism by which Fyn modulates lipid metabolism is that it inhibits AMP-activated protein kinase (AMPK). Additionally, it affects energy homeostasis through regulating specific signal pathways affecting lipid metabolism including pathways related to CD36, through enhancement of adipocyte differentiation, and through modulating insulin signal transduction. Inflammatory stress is one of the fundamental mechanisms in diabetes mellitus and its complications. Fyn also plays a role in inflammatory stress-related signaling cascades such as the Akt/GSK-3β/Fyn/Nrf2 pathway, exacerbating inflammation in diabetes mellitus. Therefore, Fyn emerges as a promising therapeutic target for regulating glucolipid metabolism and alleviating type 2 diabetes mellitus. This review synthesizes research on the role of Fyn in the regulation of energy metabolism and the development of diabetes mellitus, while exploring its specific regulatory mechanisms. Full article

Aging is a complex physiological process that profoundly affects the functionality of the musculoskeletal system, contributing to an increase in the incidence of diseases such as osteoporosis, osteoarthritis, and sarcopenia. Cellular senescence plays a crucial role in these degenerative processes, promoting chronic inflammation and tissue dysfunction through the senescence-associated secretory phenotype (SASP). Recently, senotherapeutics have shown promising results in improving musculoskeletal health. Natural compounds such as resveratrol, rapamycin, quercetin, curcumin, vitamin E, genistein, fisetin, and epicatechin act on key signaling pathways, offering protective effects against musculoskeletal decline. On the other hand, molecules such as dasatinib, navitoclax, UBX0101, panobinostat, and metformin have been shown to be effective in eliminating or modulating senescent cells. However, understanding the mechanisms of action, long-term safety, and bioavailability remain areas for further investigation. In this context, physical exercise emerges as an effective non-pharmacological countermeasure, capable of directly modulating cellular senescence and promoting tissue regeneration, representing an integrated strategy to combat age-related diseases. Therefore, we have provided an overview of the main anti-aging compounds and examined the potential of physical exercise as a strategy in the management of age-related musculoskeletal disorders. Further studies should focus on identifying synergistic combinations of pharmacological and non-pharmacological interventions to optimize the effectiveness of anti-aging strategies and promoting healthier musculoskeletal aging. Full article

Background/Objectives: Non-coding microRNA-34a (miR-34a) regulates the expression of key factors involved in several cellular processes, such as differentiation, apoptosis, proliferation, cell cycle, and senescence. Deregulation of the expression of these factors is implicated in the onset and progression of several human diseases, including cancer, neurodegenerative disorders, and pathologies associated with viral infections and inflammation. Despite numerous studies, the molecular mechanisms regulated by miR-34a remain to be fully understood. The present study aimed to generate miR-34a knockout cell lines to identify novel genes potentially regulated by its expression. Methods: We employed the CRISPR-Cas9 gene editing system to knock out the hsa-miR-34a gene in HeLa and 293T cell lines, two widely used models for studying molecular and cellular mechanisms. We compared proliferation rates and gene expression profiles via RNA-seq and qPCR analyses between the wild-type and miR-34a KO cell lines. Results: Knockout of miR-34a resulted in a decreased proliferation rate in both cell lines. Noteworthy, the ablation of miR-34a resulted in increased expression of the long non-coding RNA MALAT1. Additionally, miR-34a-5p silencing in the A375 melanoma cell line led to MALAT1 overexpression. Conclusions: Our findings support the role of the miR-34a/MALAT1 axis in regulating proliferation processes. Full article

Down syndrome (DS), stemming from the triplication of human chromosome 21, results in intellectual disability, with early mid-life onset of Alzheimer’s disease (AD) pathology. Early interventions to reduce cognitive impairments and neuropathology are lacking. One modality, maternal choline supplementation (MCS), has shown beneficial effects on behavior and gene expression in neurodevelopmental and neurodegenerative disorders, including trisomic mice. Loss of basal forebrain cholinergic neurons (BFCNs) and other DS/AD relevant hallmarks were observed in a well-established trisomic model (Ts65Dn, Ts). MCS attenuates these endophenotypes with beneficial behavioral effects in trisomic offspring. We postulate MCS ameliorates dysregulated cellular mechanisms within vulnerable BFCNs, with attenuation driven by novel gene expression. Here, choline acetyltransferase immunohistochemical labeling identified BFCNs in the medial septal/ventral diagonal band nuclei of the basal forebrain in Ts and normal disomic (2N) offspring at ~11 months of age from dams exposed to MCS or normal choline during the perinatal period. BFCNs (~500 per mouse) were microisolated and processed for RNA-sequencing. Bioinformatic assessment elucidated differentially expressed genes (DEGs) and pathway alterations in the context of genotype (Ts, 2N) and maternal diet (MCS, normal choline). MCS attenuated select dysregulated DEGs and relevant pathways in aged BFCNs. Trisomic MCS-responsive improvements included pathways such as cognitive impairment and nicotinamide adenine dinucleotide signaling, among others, indicative of increased behavioral and bioenergetic fitness. Although MCS does not eliminate the DS/AD phenotype, early choline delivery provides long-lasting benefits to aged trisomic BFCNs, indicating that MCS prolongs neuronal health in the context of DS/AD. Full article

Chemotherapy remains a cornerstone in the treatment of esophageal cancer (EC), yet chemoresistance remains a critical challenge, leading to poor outcomes and limited therapeutic success. Mitochondrial DNA (mtDNA) has emerged as a pivotal player in mediating these responses, influencing cellular metabolism, oxidative stress regulation, and apoptotic pathways. This review provides a comprehensive overview of the mechanisms by which mtDNA alterations, including mutations and copy number variations, drive chemoresistance in EC. Specific focus is given to the role of mtDNA in metabolic reprogramming, including its contribution to the Warburg effect and lipid metabolism, as well as its impact on epithelial–mesenchymal transition (EMT) and mitochondrial bioenergetics. Recent advances in targeting mitochondrial pathways through novel therapeutic agents, such as metformin and mitoquinone, and innovative approaches like CRISPR/Cas9 gene editing, are also discussed. These interventions highlight the potential for overcoming chemoresistance and improving patient outcomes. By integrating mitochondrial diagnostics with personalized treatment strategies, we propose a roadmap for future research that bridges basic mitochondrial biology with translational applications in oncology. The insights offered in this review emphasize the critical need for continued exploration of mtDNA-targeted therapies to address the unmet needs in EC management and other diseases associated with mitochondria. Full article

Reactive molecules, including oxygen and nitrogen species, serve dual roles in human physiology. While they function as essential signaling molecules under normal physiological conditions, they contribute to cellular dysfunction and damage when produced in excess by normal metabolism or in response to stressors. Oxidative/nitrosative stress is a pathological state, resulting from the overproduction of reactive species exceeding the antioxidant capacity of the body, which is implicated in several chronic human diseases. Antioxidant therapies aimed at restoring redox balance and preventing oxidative/nitrosative stress have demonstrated efficacy in preclinical models. However, their clinical applications have met with inconsistent success owing to efficacy, safety, and bioavailability concerns. This summative review analyzes the role of reactive species in human pathophysiology, the mechanisms of action of antioxidant protection, and the challenges that hinder their translation into effective clinical therapies in order to evaluate potential emerging strategies such as targeted delivery systems, precision medicine, and synergistic therapeutic approaches, among others, to overcome current limitations. By integrating recent advances, this review highlights the value of targeting reactive species in the prevention and management of chronic diseases. Full article

CNOT2, a central component of the CCR4-NOT transcription complex subunit 2, plays a pivotal role in the regulation of gene expression and metabolism. CNOT2 is involved in various cellular processes, including transcriptional regulation, mRNA deadenylation, and the modulation of mRNA stability. CNOT2 specifically contributes to the structural integrity and enzymatic activity of the CCR4-NOT complex with transcription factors and RNA-binding proteins. Recent studies have elucidated its involvement in cellular differentiation, immune response modulation, and the maintenance of genomic stability. Abnormal regulation of CNOT2 has been implicated in a spectrum of pathological conditions, including oncogenesis, neurodegenerative disorders, and metabolic dysfunctions. This review comprehensively examines the interplay between CNOT2 and p53, elucidating their collaborative and antagonistic interactions in various cellular contexts. CNOT2 is primarily involved in transcriptional regulation, mRNA deadenylation, and the modulation of mRNA stability, thereby influencing diverse biological processes such as cell proliferation, apoptosis, and differentiation. Conversely, p53 is renowned for its role in maintaining genomic integrity, inducing cell cycle arrest, apoptosis, and senescence in response to cellular stress and DNA damage. Emerging evidence suggests that CNOT2 can modulate p53 activity through multiple mechanisms, including the regulation of p53 mRNA stability and the modulation of p53 target gene expression. The dysregulation of CNOT2 and p53 interactions has been implicated in the pathogenesis and progression of various cancers, highlighting their potential as therapeutic targets. Additionally, CNOT2 regulates c-Myc, a well-known oncogene, in cancer cells. This review shows the essential roles of CNOT2 in maintaining cancer cellular homeostasis and explores its interactions within the CCR4-NOT complex that influence transcriptional and post-transcriptional regulation. Furthermore, we investigate the potential of CNOT2 as a biomarker and therapeutic target across various disease states, highlighting its significance in disease progression and treatment responsiveness. Full article

Diabetes mellitus poses a significant global health challenge, primarily due to its chronic metabolic dysregulation, leading to widespread tissue and organ damage. This systemic impact results in a range of complications that markedly reduce patients’ quality of life. Therefore it is critical to understand the mechanisms underlying these complications. DJ-1 (also known as PARK7) is a highly conserved multifunctional protein involved in antioxidative defense, metabolic equilibrium, and cellular survival. Recent studies have highlighted that DJ-1 is critically involved in the pathogenesis and progression of diabetic complications, including macrovascular issues like cardiovascular disease and microvascular conditions such as diabetic nephropathy, retinopathy, and neuropathy, suggesting that it may serve as a promising therapeutic target. Importantly, drugs targeting DJ-1 have shown therapeutic effects. This review provides a comprehensive overview of the current under-standing of DJ-1’s role in diabetes-related complications, emphasizing recent research advances. Full article

Nonalcoholic fatty liver disease (NAFLD) is a clinicopathological syndrome characterised by hepatic steatosis in the absence of significant alcohol consumption or other specific causes of liver injury. It has become one of the leading causes of liver dysfunction worldwide. However, the precise pathophysiological mechanisms underlying NAFLD remain unclear, and effective therapeutic strategies are still under investigation. Autophagy, a vital intracellular process in eukaryotic cells, enables the degradation and recycling of cytoplasmic components through a membrane trafficking pathway. Recent studies have demonstrated a strong association between impaired or deficient autophagy and the development and progression of NAFLD. Restoring autophagic function may represent a key approach to mitigating hepatocellular injury. Nevertheless, due to the complexity of autophagy regulation and its context-dependent effects on cellular function, therapeutic strategies targeting autophagy in NAFLD remain limited. This review aims to summarise the relationship between autophagy and NAFLD, focusing on autophagy as a central mechanism. We discuss the latest research advances regarding interventions such as diet and exercise, pharmacological therapies (including modern pharmacological therapy and plant-derived compounds), and other approaches (such as hormones, nanoparticles, gut microbiota, and vitamins). Furthermore, we briefly highlight potential autophagy-related molecular targets that may offer novel therapeutic insights for NAFLD management. Full article