Metabolic dysfunction-associated steatotic liver disease (MASLD), affects a substantial proportion of the global population and is closely associated with metabolic disorders. The gut microbiota, comprising a diverse community of microorganisms within the gastrointestinal tract, plays a crucial role in maintaining host health. Dysbiosis, defined as an imbalance in this microbial ecosystem, has been increasingly implicated in the development and progression of liver diseases, including MASLD. This review examines the role of the gut microbiota in MASLD pathogenesis and highlights its potential as a therapeutic target. The gut–liver axis facilitates bidirectional communication between the intestine and the liver, thereby influencing metabolic regulation. In MASLD, dysbiosis characterized by reduced microbial diversity and an increased abundance of Gram-negative bacteria leads to altered bile acid metabolism, increased intestinal permeability, enhanced endotoxin translocation, and hepatic inflammation. Additionally, it disrupts short-chain fatty acid production and interferes with the endocannabinoid system and choline metabolism, collectively driving disease progression. Emerging non-invasive diagnostic approaches, including gut microbiome profiling, show promise for early detection. Although specific pharmacological treatments remain limited, microbiota-targeted strategies such as probiotics, prebiotics, and synbiotics aim to restore microbial balance. Furthermore, emerging modalities within microbiome-based therapies, including mesenchymal stromal cell therapy and bacteriophage therapy, offer potential for targeted modulation of the gut microbiota and liver repair. The gut microbiota–liver axis plays a central role in the pathogenesis of MASLD. Growing insights into this relationship have driven the development of microbiome-based diagnostic and therapeutic approaches. Non-invasive diagnostic tools, particularly gut microbiome profiling, show promise for early detection. Therapeutically, microbiota-targeted strategies including probiotics, prebiotics, synbiotics, and emerging modalities such as cellular and bacteriophage-based therapies offer potential to restore microbial balance and improve liver function. Nevertheless, robust clinical studies are essential to validate their efficacy, safety, and applicability in personalized MASLD management.
Potassium channels constitute important signaling nodes in the progression of human cancers. Through canonical ion conduction-dependent functions, including intracellular K⁺ homeostasis, membrane potential and associated Ca²⁺ signaling, and cell volume, they influence proliferation, cell death, phenotypic plasticity, invasion and metastasis, metabolic reprogramming, and angiogenesis. Beyond ion conduction, potassium channels may affect malignant phenotypes through non-canonical mechanisms, including conformational signaling, protein interactions, transcriptional regulation, and auxiliary-subunit functions. They also contribute to tumor microenvironment remodeling by regulating immune and stromal cells and altering antitumor immune responses. However, their biological effects vary with channel subtype, tumor type, functional state, and non-canonical protein interactions, resulting in oncogenic or tumor-suppressive activity. This heterogeneity makes it hard to infer channel function from expression levels alone and also limits the development of selective therapeutic strategies. This review integrates evidence on the canonical and non-canonical functions of potassium channels across distinct cellular contexts, explains the mechanistic basis of their opposing effects, and evaluates their therapeutic potential and the major challenges to clinical translation.
Mitochondrial dysfunction plays a critical role in the development of metabolic dysfunction-associated steatotic liver disease (MASLD). It has been proposed that mitochondrial unfolded-protein response (UPRmt) activation improves mitochondrial function in the liver. Growing evidence demonstrates that physical exercise effectively prevents and treats MASLD. However, the effects of exercise on UPRmt activation in the liver are unknown. Thus, we investigated the impact of aerobic training on the mechanisms involved in mitochondrial quality control in the liver in a mouse model of obesity. Liver transcript data from a genetic reference panel of BXD isogenic mice revealed a negative correlation between UPRmt-related genes and hepatic triacylglycerol content. In addition, the liver UPRmt markers were strongly associated with several mitochondrial-related genes in the hepatic tissue of BXD mice and humans. Notably, 4 weeks of aerobic exercise strongly impacted the liver metabolism, preventing intrahepatic lipid accumulation in HFD-fed mice. Physical exercise boosted the NAD-biosynthesis pathway, elicited the mitonuclear protein imbalance, stimulated the protein content of UPRmt-markers, including CLpP, Lonp1, and Yme1L1, and improved the mitochondrial proteostasis and function in the liver in HFD-fed mice. Thus, our findings link the mitonuclear protein imbalance and UPRmt activation in the liver to mitochondrial proteostasis and MASLD prevention in response to physical exercise.
Understanding the multiple mechanisms underlying peripheral nerve regeneration in humans is crucial for developing effective therapies for peripheral axonal neuropathies. Although in vitro and in vivo studies have provided significant insights, human studies exploring the composition of proteome remain limited. The ECM plays a crucial role in nerve regeneration, influencing cell adhesion, proliferation, migration, and finally differentiation. In this study, we used a high-sensitivity, label-free liquid chromatography-mass spectrometry (LC-MS) method to investigate the global proteomic profile of human sural nerves aiming to identify molecular dynamics that promote or hinder nerve regeneration in well-characterized cohorts of patients with acute axonal injury, regenerating axonal neuropathy, and non-regenerating axonal neuropathy. Overall, 149 proteins were identified, of which 68 showed significant modulation across the groups. Proteins over-represented in regenerating nerves highlighted the multifactorial nature of regeneration, including immune modulation, debris clearance, cytoskeletal reorganization, axonal extension, and lipid transport. Conversely, structural myelin and neuronal proteins were significantly downregulated in non-regenerating nerves. Among the differentially expressed proteins, functional enrichment analysis revealed a significant overrepresentation of ECM-related components, providing compelling evidence that the ECM is not merely a passive scaffold, but an active driver of peripheral nerve regeneration. ECM remodeling contribute to / influence regenerative outcomes in human axonal neuropathies. Acutely injured nerves display enrichment in wound-response proteins, consistent with blood–nerve barrier disruption, and formation of a fibrin/fibronectin-rich ECM that supports repair. Regenerating nerves exhibit a dynamic ECM and a proteomic profile similar to those of controls, reflecting the restoration of a permissive regenerative environment. Non-regenerating nerves exhibit ECM accumulation and reduced levels of neuronal/myelin structural proteins, consistent with chronic regenerative failure.
Parkinson's disease (PD), a prevalent neurodegenerative disorder, is characterized by the degeneration of dopaminergic neurons in the substantia nigra and striatum of the midbrain, manifesting as distinct motor impairments. While conventional theories attribute PD's development to neuronal damage, astrocytes have garnered significant attention for their potential protective role. As the most abundant glial cells in the central nervous system (CNS), astrocytes may exert neuroprotective effects through mechanisms including secretion of neurotrophic factors, regulation of the blood-brain barrier (BBB), and maintenance of water-electrolyte balance. Recent studies indicate that mutations in PD-associated genes may induce functional alterations in astrocytes. Activated astrocytes accelerate neuronal degeneration by releasing inflammatory mediators, disrupting glutamate homeostasis, and triggering oxidative stress. Furthermore, bidirectional regulatory interactions exist between astrocytes and both dopaminergic neurons and other glial cells in PD. This review systematically summarizes current research on astrocyte involvement in PD pathology and their neuronal interaction mechanisms, further exploring their interconnections to elucidate disease pathogenesis. The findings provide novel theoretical frameworks for developing astrocyte-targeted therapies and preventive strategies against PD.
The LKB1-AMPK signaling pathway is a central regulator of hepatic energy homeostasis and is increasingly implicated in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). LKB1-mediated AMPK activation promotes fatty acid β-oxidation, autophagy, and mitochondrial biogenesis. At the same time, it suppresses de novo lipogenesis, cholesterol synthesis, and mTOR-dependent anabolic growth, thereby supporting hepatic lipid and energy balance. Impairment of this pathway may disrupt hepatic lipid homeostasis and promote triglyceride accumulation. Oxidative stress, microRNA dysregulation, hormonal imbalance, copper dysregulation, and inflammatory mediators can further contribute to mitochondrial injury, hepatocellular apoptosis, and inflammatory activation. These processes may facilitate progression from simple steatosis to non-alcoholic steatohepatitis (NASH), fibrosis, and hepatocarcinogenesis. LKB1-AMPK signaling also intersects with immunometabolic and stromal pathways. Defects in hepatic immune and stromal compartments may enhance pro-inflammatory Th17 responses and fibrogenic transformation. Therapeutically, pharmacologic activation of LKB1-AMPK has shown context-dependent cytoprotective potential, mainly in preclinical models. Natural compounds, synthetic small molecules, repurposed agents, and nutrient-derived modulators can activate LKB1-AMPK signaling. These interventions reduce steatosis, oxidative stress, and endoplasmic reticulum stress while enhancing autophagic flux and fatty acid catabolism. Additional benefits may arise through gut microbiota-mediated signaling that converges on LKB1-AMPK-dependent metabolic restoration. Overall, the LKB1-AMPK axis links nutrient sensing, mitochondrial function, redox control, and inflammatory regulation in NAFLD pathophysiology. Current evidence supports further development of pathway-targeted interventions, but clinical translation requires stronger human validation.
Adenosine monophosphate-activated protein kinase (AMPK) is an evolutionarily conserved serine/threonine kinase that links cellular energy stress with metabolic adaptation, autophagy, redox homeostasis, and cell fate decisions. Necroptosis is a regulated lytic form of cell death driven by receptor-interacting serine/threonine kinases 1 and 3 (RIPK1 and RIPK3), with mixed lineage kinase domain-like protein (MLKL) serving as the terminal executor. Increasing evidence suggests that AMPK modulates necroptosis through multiple interconnected mechanisms. AMPK directly phosphorylates RIPK1, thereby influencing necroptotic signaling in a context- and time-dependent manner. Through the AMPK-mTOR axis, AMPK also regulates autophagy and mitophagy, affecting inhibitory control of RIPK1 and autophagic turnover of RIPK3. In parallel, AMPK suppresses necroptosis through SIRT1- and PGAM5-related pathways, limiting necrosome assembly, mitochondrial dysfunction, and Drp1-dependent mitochondrial fission. AMPK further shapes reactive oxygen species (ROS)-associated necroptotic responses through downstream effectors, including mTOR and Nrf2. In this review, we summarize recent advances in the mechanisms by which AMPK regulates necroptosis and highlight unresolved questions, including the cell-type-specific roles of AMPK subunits, the contribution of additional autophagy regulators, the balance between mTORC1-dependent protective signaling and RIPK3 stability, and the in vivo relevance of the AMPK-SIRT1-PGAM5 axis. Clarifying this regulatory network may facilitate the development of therapeutic strategies for necroptosis-related diseases, including metabolic disorders, ischemia-reperfusion injury, and neurodegeneration. Collectively, the available evidence indicates that AMPK acts as a context-dependent regulator of necroptosis rather than a universally protective kinase.
Obesity is a major risk factor for Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) and its progressive form, Metabolic Dysfunction-Associated Steatohepatitis (MASH). Bacterial cyclodipeptides (CDPs) have previously been shown to modulate PI3K/Akt/mTOR signaling and transcriptional programs involved in lipid and cholesterol metabolism, highlighting their potential to regulate metabolic homeostasis. Given the central role of the PI3K/Akt/FoxO1 pathway in regulating aquaporins, inflammatory cytokines, and metabolic homeostasis during obesity and MASLD, the therapeutic potential of CDPs was evaluated in a rat model of MASLD. Treatment of obese animals with CDPs decreased body weight and abdominal and thoracic circumferences. The obesogenic diet induced liver damage after the 34th week, which was alleviated by ten weeks of CDP treatment administered three times a week. This reduced the number and size of lipid droplets and inflammatory infiltrates. Additionally, CDPs improved parameters associated with atherogenic dyslipidemia and metabolic dysfunction, including triglycerides and cholesterol, as well as hepatic injury markers. These changes were accompanied by restoration of mitochondrial membrane potential and a significant reduction in mitochondrial ROS generation. CDP treatment in obese animals restored protein expression levels of aquaporins AQP1, AQP5, AQP8, and AQP9 and downregulated the expression of the inflammatory markers NF-κB and IL-1β. Interestingly, the downstream cellular mediator GAB1 from the PI3K/Akt/FoxO1 pathway was also downregulated. These findings demonstrate that CDP treatment restored the expression of glycerol/water transporting aquaporins altered during obesity and MASLD. Overall, CDPs ameliorated MASLD in obese animals through coordinated modulation of lipid metabolism, mitochondrial function, aquaporin expression, and PI3K/Akt/FoxO1 signaling associated with inflammation, supporting their potential as therapeutic candidates for metabolic liver disease. Anti-obesity and hepatoprotective effects of CDPs. Anti-obesity mechanism of CDPs involves the expression of aquaporins. CDPs modulate the expression of the NF-κB, IL-1β factors, and GAB1 factor.
The inwardly rectifying K+ channel Kir7.1 is prominently expressed at the apical membrane of the choroid plexus epithelium (CPE) and defines the membrane potential of these cells. The unusual independence of its conductance of extracellular K+ ([K+]o) underpins an important role in the regulation of the concentration of this ion in the cerebrospinal fluid [K+]CSF. A similar function for retinal pigment epithelium (RPE) Kir7.1 has been proposed with respect to subretinal K+ ([K+]SRS) buffering. We have now studied the effect of expressing in mice the mutant Kir7.1-L241P, a blindness-associated Leber’s congenital amaurosis mutation, on channel expression and function in the CPE and on [K+]CSF, taken as a proxy for less accessible [K+]SRS. We used genome-edited knockin mice carrying the L241P mutation of Kir7.1 and studied the electrical properties and NKCC1 cotransporter activity of CPE cells in vitro, as well as CSF secretion rate and [K+]CSF in vivo. CPE cells from Kir7.1-L241P knockin mice had a two-third reduction in K+ conductance with respect to that of cells from control animals. While CSF secretion rates and NKCC1 cotransporter activity were unaltered in mutant animals, [K+]CSF was significantly decreased while [Na+]CSF is increased. These results reaffirm the importance of choroid plexus Kir7.1 in the regulation of [K+]CSF. We speculate that the alteration in [K+]CSF regulation by mutation Kir7.1-L241P might be paralleled by a disease-related impairment of retinal [K+]SRS buffering. The choroid plexus (CPE) and retinal pigment (RPE) epithelia respectively flank the cerebrospinal and subretinal space fluids. CPE and RPE are the sites of highest expression of Kir7.1 K+ channels in mammals, and from these locations K+ concentration is regulated in the cerebrospinal and subretinal space fluids respectively. Genome-edited mice carrying the blindness-associated Kir7.1-L241P mutant showed decreased channel function in the CPE and disturbed regulation of K+ in the cerebrospinal fluid. A similar failure in the regulation of retinal K+ concentration may be associated with the blindness phenotype.
Brown adipose tissue (BAT) activity in humans is linked to better glucose metabolism and cardiometabolic health. In mice, cold exposure increases circulating succinate and enhances BAT thermogenesis, but whether similar succinate responses occur in humans remains undetermined. We analysed data from 33 young (18–25 years), sedentary adults (20 women) from the ACTIBATE cohort (NCT02365129). Plasma succinate was measured enzymatically at baseline and 60 and 120 min during a personalized cooling protocol. BAT volume, activity, and radiodensity were assessed via static 18F-fluorodeoxyglucose positron emission tomography–computed tomography (18F-FDG PET-CT) at the end of the cold exposure. Circulating succinate changed over time during cold exposure, with no significant change at 60 min and a significant increase at 120 min versus baseline (+ 23.8
This study aims to investigate the role of the deubiquitinase OTUB1 in regulating sleep deprivation-induced cognitive impairment in mice and to elucidate the underlying molecular pathways. A mouse model of sleep deprivation was established, and mice were pretreated with OTUB1 protein. Cognitive function was assessed using the Y-maze test, the novel object recognition test (NORT), and the open field test. In vitro experiments involved the generation of OTUB1-overexpressing cell lines. Target gene expression was analyzed by western blot, qRT-PCR, and ELISA assays. Protein-protein interactions were assessed via co-immunoprecipitation. Our findings revealed a decrease in heat shock protein 70 (HSP70) protein levels in the hippocampus of sleep-deprived mice, along with an interaction between OTUB1 and HSP70 in mouse microglial cells. OTUB1 stabilized HSP70 by reducing its polyubiquitination. Furthermore, OTUB1 ameliorated sleep deprivation-induced cognitive deficits and reduced neuroinflammation in the hippocampus, as evidenced by changes in cytokine levels. OTUB1 mitigates sleep deprivation-induced cognitive impairment and neuroinflammation in the hippocampus by stabilizing HSP70 and attenuating inflammatory responses.
Mitochondrial impairment, accompanied by excessive reactive oxygen species (ROS) production, is a key contributor to muscle atrophy and neuromuscular disorders, leading to locomotor and respiratory failure. Antimycin A (AA), an inhibitor of the electron transport chain complex III, is an effective tool to mimic mitochondrial dysfunction, whereas 25-hydroxycholesterol (25-HC) is an immune-related oxysterol that can modulate neuromuscular activity via the membrane estrogen receptor α (ERα)/inositol triphosphate receptor/cytoplasmic Ca2+ axis. Herein, we investigated the effects of AA treatment in mouse diaphragm nerve-muscle preparations and tested the hypothesis that 25-HC can mitigate AA-induced mitochondrial damage. AA increased mitochondrial ROS production and reduced mitochondrial Ca2+ levels and membrane potential. This was accompanied by an elevation of extracellular H2O2 levels and lipid peroxidation, as well as a decline in both muscle fiber contractility and evoked exocytosis at the neuromuscular junction (NMJ). Furthermore, alterations were observed in the shape of miniature end-plate responses to the release of single neurotransmitter quanta. 25-HC, at a submicromolar concentration, inhibited AA-induced mitochondrial dysfunction and oxidative stress. Additionally, 25-HC alleviated AA-dependent functional NMJ disturbances but did not reverse the muscle fiber contraction deficit. The ability of 25-HC to decrease AA-driven mitochondrial ROS generation was blocked by a selective ERα antagonist and by chelation of cytoplasmic Ca2+. Thus, AA induces mitochondrial damage accompanied by oxidative stress, contractile and NMJ impairments. 25-HC can counteract AA-mediated mitochondrial dysfunction and partially restore NMJ function.
Pyroptosis is a lytic form of cell death that is highly regulated and executed by certain members of the Gasdermin protein family. The lytic process occurs because the N-terminal domains of gasdermins possess pore-forming capabilities, thereby leading to cellular swelling and plasma membrane rupture. This process is characterized by membrane pore formation – mediated by caspase-cleaved gasdermins—followed by cell lysis and the release of pro-inflammatory mediators. Depending on the nature of stimuli, different inflammasomes and caspases are activated, leading to pyroptosis via two main mechanisms: the caspase-1-dependent canonical pathway and caspase-1-independent non-canonical pathway. In this review, we first summarize the current understanding of pyroptosis, including its underlying mechanisms and the diverse stimuli that trigger it. We then highlight recent findings related to altered signaling pathways and regulatory mechanisms. Finally, we discuss emerging perspectives and its implications, aiming to deepen insight into this form of cell death and stimulate new avenues for research.
Rheumatic heart disease (RHD) is a chronic sequel of acute rheumatic fever characterized by sustained inflammation, fibrosis, and valve degeneration; however, the underlying processes remain unclear. To identify dysregulated molecular pathways, we conducted LC-MS/MS-based proteomic profiling of RHD mitral valve tissue compared with ischemic controls and validated systemic inflammation in RHD patients through peripheral blood analysis. Proteomic analysis revealed upregulation of immune response proteins, TGFβ signaling, and extracellular matrix (ECM) regulators. Notably, proteins associated with innate immune activation and macrophage-related pro- and anti-inflammatory responses were found to be enriched. Peripheral blood analysis further confirmed elevated levels of IL6, TNFα, and TIMP1, indicating systemic inflammation. To investigate the underlying mechanisms, we isolated human valve interstitial cells (hVICs) and treated them with proinflammatory stimuli (TNFα, IFNγ) and profibrotic/ anti-inflammatory (TGFβ) stimulation. TGFβ induced morphological changes within 24 h, consistent with fibrotic transformation, and upregulated fibrotic markers (ACTA2, COL1A1, COL1A2, TIMP1, CTGF, MMP2, and TGFβ) along with increased collagen deposition. In contrast, TNFα and IFNγ suppressed fibrotic gene expression while upregulating TIMP1. Notably, TGFβ induced canonical Smad3 phosphorylation, whereas TNFα and IFNγ did not find, any change. Further, macrophage-hVIC interactions were evaluated using conditioned media from M1 [LPS (100 ng/ml) + TNFα (10 ng/ml)] and M2c [TGFβ (10 ng/ml)] polarized macrophages. M2c macrophage-conditioned media enhanced profibrotic gene expression, whereas M1-conditioned media suppressed it, highlighting the role of immune–fibrotic crosstalk in valvular fibrosis. Notably, the 5-HT₂B receptor antagonist SB204741 and tadalafil effectively inhibited TGFβ-induced Smad3 phosphorylation in hVICs, thereby reducing fibrotic signaling. In addition, tadalafil selectively suppressed ERK1/2-mediated non-canonical signaling, while no significant changes were observed in the STAT3, p38 MAPK and JNK pathways. Collectively, these findings identify immune–fibrotic crosstalk and selective activation of canonical TGFβ/Smad3 and ERK1/2-mediated non-canonical signaling pathways as important contributors to valvular fibrosis in rheumatic heart disease and suggest that targeting these pathways may provide potential therapeutic approaches to limit disease progression. Proteomic profiling identified deregulation of immune response, TGFβ signaling, and extracellular matrix remodeling pathways in the progression of rheumatic heart disease. Established a reproducible protocol for isolation of human valve interstitial cells (hVICs) and demonstrated that TGFβ induces profibrotic responses, whereas TNFα and IFNγ suppress fibrotic gene expression. Macrophage-conditioned media induced differential responses in hVICs, with M2c macrophages promoting profibrotic signaling and M1 macrophages showing antifibrotic effects. Tadalafil and SB204741 attenuated TGFβ-induced Smad3 signaling in hVICs, while tadalafil additionally suppressed ERK1/2-mediated non-canonical signaling, supporting their potential as antifibrotic therapeutic agents in rheumatic heart disease.
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in xenobiotic sensing and multiple physiological functions, including intestinal homeostasis. Aging is associated with reduced colonic motility and constipation, but the contribution of AhR to intestinal motor function across sex and age remains incompletely defined. We performed a phenotypic characterization of AhR-deficient (AhR−/−) and wild-type (WT) C57BL/6J mice in both sexes at two ages (young: 4–6 months; adult: 12–13 months). Lifespan, body weight, food and water intake were monitored longitudinally. Body composition (DXA), hematological parameters, fecal output features (number, length, moisture and stool color analysis), ex vivo colonic function in organ bath (spontaneous peristalsis with or without L-NAME and responses to acetylcholine and norepinephrine), histological muscle thickness, and molecular markers (PGP9.5 and NOS1 protein; Nos1, Nos2, Aqp1/3/4/8, Il6, Il10 gene expression) were assessed. AhR−/− mice exhibited reduced survival and attenuated body weight gain, particularly in females, without differences in food consumption but with increased water intake. Fecal length and moisture were unchanged; however, AhR−/− females displayed fewer stools at both ages. Ex vivo, spontaneous peristaltic amplitude was selectively reduced in AhR−/− females at both ages, whereas males were unaffected. L-NAME increased spontaneous peristalsis in WT males but not in AhR−/− males, suggesting impaired nitrergic modulation in the absence of AhR. Acetylcholine-induced contraction was reduced in young AhR−/− females but not in adults. Histology revealed reduced colonic muscle thickness in young AhR−/− females only, accompanied by decreased PGP9.5 protein expression. Gene expression showed sex- and age-dependent changes in Nos1/Nos2, aquaporins, and inflammatory markers. AhR deficiency leads to a sex-dependent colonic motor phenotype predominantly affecting females, integrating functional impairment with early neuromuscular remodeling and altered neural markers. These findings support AhR as a regulator of intestinal motor function with potential relevance to age-related dysmotility.
Excessive dietary fat intake is a major health concern, contributing to the increasing prevalence of Metabolic Dysfunction Associated with Fatty Liver Disease (MAFLD) worldwide; different prevalence between sexes has been postulated but it is not clear. This study evaluated the effects of a high-fat diet (HFD) in Wistar rats and the impact of a transition to standard or antioxidant-rich diets in the same animals, exploring differences between sexes. Female and male animals were maintained for 5 months: control (chow diet) and HFD groups throughout the study, and two intervention groups switched after 3 months from HFD to standard or antioxidant-rich diets. Body weight was monitored, hepatic lipid accumulation, plasma levels of glucose, advanced glycation end-products, interleukin-6, and polyphenolic content, and hepatic oxidative stress markers (catalase, superoxide dismutase, glutathione peroxidase, and malondialdehyde) were measured, along with gene expression related to inflammation and lipid metabolism. HFD significantly increased body weight (females: 123.9 ± 13.57 g; males: 163.1 ± 9.97 g) and hepatic lipid accumulation (female proportion: 9.4 ± 0.4; male proportion: 10.5 ± 0.2) compared with control group (females: 28.96 ± 3.95 g; males: 86.29 ± 3.79 g, p < 0.01; 0
It has been proposed that muscle influences adjacent bones, but the mechanisms by which muscle regulates bone physiology are not fully understood. Sciatic denervation is an experimental model that induces both skeletal muscle atrophy and osteoporosis. Therefore, the aim of this study was to analyze, in this animal model, expression of myokines in the atrophic soleus and its possible effect on changes in tibia microarchitectural parameters in 9-12 weeks old male rats. For this purpose, soleus insulin-like growth factor-1 (IGF-1), interleukin-6 (IL-6), fibronectin type III domain-containing 5 (FNDC5), fibroblast growth factor 21 (FGF21) mRNA, and miR-150, were measured by real-time PCR and tibia microarchitecture was assessed 3, 7, and 14 days after sciatic denervation. Denervation induced soleus atrophy and decreased trabecular bone density, thickness, and number. In the atrophic soleus, there was an increase in IL-6, IGF-1, and FGF21 mRNA, with a decrease in FNDC5 mRNA and miR-150 levels. No correlation between soleus IL-6 or IGF-1 and trabecular bone parameters was found. However, FGF21 was negatively correlated with trabecular bone mineral content, whereas FNDC5 mRNA and miR-150 levels were positively correlated. These data suggest that modifications in FGF21, FNDC5, and miR-150 during muscle atrophy may mediate muscle-bone crosstalk and contribute to bone loss, while IL-6 and IGF-1 do not seem to play a predominant role.
The field of malignant tumor diagnosis and treatment urgently requires innovative research perspectives to overcome the existing limitations. Extracellular vesicles (EVs) are crucial mediators of intercellular communication, offering novel avenues for regulating tumors. Among these, extracellular vesicles derived from adipose-derived stem cells (ADSC-EVs) have garnered significant attention because of their exceptional stability, safety profile, and ease of storage and transportation. Here, we first elucidate the biological foundation of ADSC-EVs, delineating their biogenesis pathway characterized by the “early endosome–multivesicular body–extracellular release” process, and highlight the heterogeneity of their molecular cargo. This cargo includes 148 regulatory microRNAs (such as the let-7 family and miR-122), 1,466 functional proteins, and various lipid molecules, thereby underpinning its multifunctional regulatory potential. Mechanistically, the dual role of ADSC-EVs is emphasized: on one hand, they can activate signaling pathways, such as PI3K/AKT, or modulate metabolic reprogramming to promote tumor proliferation; on the other hand, they exert tumor-suppressive effects by delivering specific microRNAs (e.g., miR-503-3p) and remodeling the tumor immune microenvironment to influence tumor progression. From an application standpoint, the tripartite value of ADSC-EVs is underscored: serving as potential biomarkers to assist in tumor diagnosis and classification, enabling targeted delivery of anticancer agents following engineering modifications, and functioning as acellular tools that circumvent the risks associated with conventional stem cell therapies. In summary, this study constructed a comprehensive framework for the application of ADSC-EVs in tumor diagnosis and treatment, providing both theoretical and practical support for overcoming therapeutic bottlenecks and developing precision strategies.
Obstructive sleep apnea (OSA) is frequently complicated by hypertension, with approximately 60% of patients exhibiting both conditions. However, the epigenetic mechanisms underlying this comorbidity remain largely unexplored. N6-methyladenosine (m6A), the most abundant internal RNA modification, has emerged as a critical regulator of cardiovascular pathology, yet its role in OSA-associated hypertension (OSA-HTN) is unknown. Here, we investigated the contribution of m6A RNA methylation to OSA-HTN pathogenesis. In a chronic intermittent hypoxia (CIH) mouse model and hypoxia-stimulated aortic vascular smooth muscle cells (AVSMCs), we observed marked inflammatory injury, pyroptosis, and decreased expression of methyltransferase-like 3 (METTL3) along with global m6A levels. Overexpression of METTL3 significantly attenuated hypoxia-induced pyroptosis and inflammation by downregulating SRY-box transcription factor 4 (SOX4), a pro-inflammatory transcription factor. Mechanistically, CIH suppressed YTH N6-methyladenosine RNA-binding protein 2 (YTHDF2), an m6A reader that directly binds SOX4 mRNA, while METTL3-mediated m6A modification enhanced YTHDF2-dependent SOX4 mRNA degradation. Knockdown of YTHDF2 abolished the suppressive effect of METTL3 on SOX4 stability, confirming a METTL3-m6A-YTHDF2 regulatory axis. This METTL3-dependent regulation of YTHDF2-SOX4 interaction and SOX4 mRNA decay was also validated in mouse aortic endothelial cells. Furthermore, in vivo silencing of SOX4 alleviated CIH-induced pyroptosis and inflammation in cardiac and aortic tissues. Notably, pharmacological activation of METTL3 or METTL3 overexpression similarly attenuated CIH-induced cardiac and aortic tissue injury in OSA-HTN mice. In conclusion, our findings identify a novel METTL3-YTHDF2-SOX4 axis that governs hypoxia-induced pyroptosis and inflammation, providing new mechanistic insights into the epigenetic regulation of OSA-HTN and highlighting potential therapeutic targets.
