Search Results (81)

Extracellular vesicles (EVs) can disseminate replication-competent viral genomes complexed with selected host proteins, enabling stealth cell-to-cell transfer within lipid membrane-enclosed bubbles. In addition to complementing free-virion spread, EV-associated genomes can be protected from neutralizing antibodies and persist under conditions in which classical virion production decreases. Here, we propose a route-resolved framework in which interconnected cellular secretory pathways, including endoplasmic reticulum (ER) remodeling, multivesicular body (MVB) biogenesis, secretory autophagy, and plasma-membrane budding, jointly generate EV heterogeneity and create discrete opportunities for the capture, protection, and export of infectious cargo. We highlight reticulon-3 (RTN3), an ER-shaping protein, as an upstream regulator that can couple infection-induced ER microdomains to endosomal docking and to autophagy-linked trafficking decisions that bias intermediates toward secretion rather than degradation. Supporting this view, transmission electron microscopy of dengue virus-infected cells reveals extensive vesicular remodeling, including irregular MVBs adjacent to the plasma membrane and autophagosome-like double-membrane structures, consistent with altered vesicular routing following RTN3 perturbation. Collectively, these route-resolved, spatially organized spatio-organelle changes support a pathomechanistic model in which RTN3-mediated ER remodeling reshapes ER-endosome-autophagy trafficking interfaces, creating regulated decision points that can be leveraged to stratify infectious EV subsets (with infectivity-linked single-vesicle and quantitative proteomics approaches) and to inform host-directed strategies that curb non-lytic viral dissemination. Full article

Vascular ageing is a complex process marked by progressive endothelial dysfunction, chronic low-grade inflammation (“inflammageing”), and reduced regenerative capacity, driven in part by an imbalance between protective endothelial autophagy and cellular senescence characterized by a proinflammatory senescence-associated secretory phenotype (SASP). Disruption of this autophagy–senescence axis accelerates vascular inflammation, arterial stiffening, and atherogenesis. High-intensity interval training (HIIT), consisting of repeated bouts of near-maximal anaerobic effort with recovery periods, is widely used by both elite and recreational athletes and is increasingly recognized as an effective nonpharmacological strategy to enhance endothelial function, arterial elasticity, and mitochondrial biogenesis. However, excessively intense or poorly structured HIIT, particularly in the absence of adequate recovery or in individuals with underlying cardiometabolic or vascular vulnerability, may induce endothelial stress and promote maladaptive vascular remodelling, including calcification and plaque instability. These considerations underscore the need for refined individualized exercise prescription strategies that balance performance benefits with endothelial protection. Based on these observations, here, we introduce a novel conceptual framework, “shear dose–calibrated HIIT,” designed to understand and define an optimal shear dose capable of maximizing autophagic flux while minimizing SASP activation. Experimental and clinical evidence of HIIT-induced effects on flow-mediated dilation (FMD), pulse wave velocity (PWV), and redox biomarkers is presented, followed by the proposal of a biomarker panel for assessing autophagic flux and cellular senescence in peripheral samples (peripheral blood mononuclear cells (PBMCs), extracellular vehicles (EVs), and plasma). This integrative approach, which combines vascular mechanotransduction, redox biology, and autophagic signalling, provides a novel translational perspective on how individually calibrated HIIT can promote vascular longevity and reduce cardiometabolic risk associated with aging and metabolic syndrome. Full article

Age-related osteoporosis is driven in part by senescence-associated rewiring of bone marrow mesenchymal stem cells (MSCs) from osteogenic toward adipogenic fates. Accumulating evidence indicates that epigenetic drift and reduced autophagy are not isolated lesions but are mechanistically coupled through a bidirectional DNA methylation and autophagy axis. Here, we summarize how promoter hypermethylation of genes involved in autophagy and osteogenesis suppresses autophagic flux and osteoblast lineage transcriptional programs. Conversely, autophagy insufficiency reshapes the methylome by limiting methyl donor availability, most notably S-adenosylmethionine (SAM), and by reducing the turnover of key epigenetic regulators, including DNA methyltransferases (DNMTs), ten-eleven translocation (TET) dioxygenases, and histone deacetylases (HDACs). This self-reinforcing circuitry exacerbates mitochondrial dysfunction, oxidative stress, and inflammation driven by the senescence-associated secretory phenotype (SASP), thereby stabilizing adipogenic bias and progressively impairing marrow niche homeostasis and bone remodeling. We further discuss therapeutic strategies to restore balance within this axis, including selective modulation of epigenetic enzymes; activation of AMP-activated protein kinase (AMPK) and mechanistic target of rapamycin (mTOR) signaling with downstream engagement of Unc-51-like autophagy-activating kinase 1 (ULK1) and transcription factor EB (TFEB); targeting sirtuin pathways; mitochondria- and autophagy-supportive natural compounds; and bone-targeted delivery approaches or rational combination regimens. Full article

Immunogenic cell death (ICD) is a subtype of regulated cell death characterized by the spatiotemporally coordinated emission of damage-associated molecular patterns (DAMPs), such as calreticulin (CALR), ATP, and high-mobility group box-1 (HMGB1), which collectively prime tumor-specific T-cell responses. Autophagy, a lysosome-dependent catabolic process, is increasingly recognized as a key modifier of antitumor immunity and the tumor microenvironment (TME). In preclinical models, autophagy can not only promote ICD by sustaining endoplasmic reticulum (ER) stress, eukaryotic translation initiation factor-2α (eIF2α) phosphorylation, and secretory pathways, but it can also limit ICD by degrading DAMPs, antigenic cargo, and major histocompatibility complex (MHC) molecules. The net outcome is highly context-dependent and determined by the tumor type, the nature and intensity of the stress, and the level at which autophagy is modulated. Herein, we summarize how autophagy affects the three canonical ICD-associated DAMPs, highlight solid-tumor models in which autophagy supports ICD, and contrast them with systems wherein autophagy inhibition is required for immunogenicity. We then focus on hematological malignancies, especially multiple myeloma, where recent reports implicate the autophagy-related protein GABARAP in bortezomib-induced ICD. Finally, we discuss the translational implications, including rational combinations of autophagy modulators with ICD-inducing chemotherapies, targeted drugs, and cellular immunotherapies, and outline the remaining challenges for safely harnessing the autophagy–ICD axis in the clinical setting. Full article

Cells are constantly exposed to mechanical forces that shape their behavior, survival, and fate. The autophagy machinery emerges as a central adaptive pathway in these processes, acting not only as a metabolic and quality control mechanism but also as a key regulator of membrane dynamics and mechanotransduction. Here, we review how mechanical stress influences autophagy initiation, autophagosome maturation, and lysosomal function across different cell types. We discuss parallels between leukocyte diapedesis and circulating tumor cell (CTC) extravasation, two processes that involve profound mechanical challenges and rely on autophagy-related pathways to maintain cell integrity and enable transendothelial migration. Special attention is given to the dual role of autophagy-related proteins (ATGs) in these contexts, ranging from cytoplasmic degradation dependent on lysosomal fusion to secretory functions. Understanding how mechanical forces modulate autophagy and ATG-dependent pathways may reveal novel insights into immune regulation, tumor dissemination, and potential therapeutic targets aimed at controlling inflammation and metastasis. Full article

Obesity is a systemic metabolic disorder that is known to impair various organ systems; however, its precise impact on salivary gland homeostasis remains unclear. Recent studies have implicated ferroptosis—an iron-dependent form of regulated cell death characterized by lipid peroxidation and oxidative stress—in glandular dysfunction. In this study, we used leptin-deficient (ob/ob) mice to elucidate the role of ferroptosis in obesity-associated salivary gland pathology. The protective effects of ferroptosis inhibition were evaluated by administering ferrostatin-1 (a lipid reactive oxygen species [ROS] scavenger) and deferoxamine (an iron chelator) for an 8-week period. Obese mice exhibited significantly increased body weight, food intake, and hyperglycemia. These systemic changes are accompanied by profound histological alterations in the salivary glands, including lipid droplet accumulation, acinar atrophy, and mitochondrial ultrastructural damage. These alterations correlate with the hallmarks of ferroptotic injury, including increased ROS levels (p < 0.001), elevated malondialdehyde levels (p < 0.01), suppressed glutathione peroxidase 4 activity (p < 0.01), and iron overload (p < 0.001). Salivary gland fibrosis, inflammation, and secretory dysfunction were evident, characterized by the upregulation of TGF-β (p < 0.01) and Collagen I (p < 0.05), reduced expression of aquaporin-5 and amylase, and dysregulated levels of autophagy-related markers (LC3B and p62). Treatment with either ferrostatin-1 or deferoxamine significantly mitigated these pathologies; however, the degree of efficacy varied depending on the specific parameters that were examined. Thus, our findings implicate ferroptosis as a critical contributor to salivary gland dysfunction in obesity and suggest that pharmacological inhibition of this pathway represents a viable therapeutic strategy for preserving glandular integrity under metabolic stress. Full article

Background: Endometriosis is a chronic inflammatory disorder that affects approximately 10% of women of reproductive age and exhibits tumor-like characteristics such as invasion, recurrence, and hormone-dependent proliferation despite its benign nature. Its pathogenesis is thought to involve hormonal imbalance, oxidative stress, hypoxia, immune dysregulation, and epigenetic alterations. This review summarizes how these factors contribute to lesion formation through intracellular signaling pathways, with a particular focus on the role of the stress-responsive transcription factor Forkhead box O (FOXO1). Methods: A comprehensive literature search was conducted using PubMed and Google Scholar without temporal restriction. Results: FOXO1 is a transcription factor that integratively regulates decidualization, cellular senescence, autophagy, and apoptosis. In the normal endometrium, under mild stress or hormonal stimulation, FOXO1 induces decidualization-associated genes (PRL, IGFBP1) and antioxidant enzymes, thereby promoting differentiation and survival. In contrast, in endometriosis, activation of the PI3K/AKT signaling pathway and an estrogen-dominant environment suppress the nuclear activity of FOXO1, leading to apoptosis resistance, accumulation of senescent cells, and chronic inflammation through the senescence-associated secretory phenotype (SASP). Moreover, depending on the intensity and duration of oxidative, metabolic, and environmental stress, FOXO1 drives distinct cellular fates—including decidualization, senescence, and apoptosis—thus contributing to the persistence and progression of endometriotic lesions. Conclusion: Dysregulation of the FOXO1-dependent cellular fate–control network plays a central role in the development of endometriosis. Elucidating the molecular mechanisms governing FOXO1 activity and its nuclear dynamics will be crucial for a comprehensive understanding of disease progression and for the development of novel therapeutic strategies. Full article

Aging is characterized by a chronic, low-grade inflammatory state known as inflammaging, which closely interacts with immunosenescence—the gradual deterioration of immune function. Together, these processes contribute to tissue dysfunction and the development of age-related diseases. This review explores the cellular and molecular mechanisms underlying inflammaging, including mitochondrial dysfunction, telomere attrition, impaired autophagy, and gut microbiota dysbiosis. A particular emphasis is given to the senescence-associated secretory phenotype (SASP), which sustains a pro-inflammatory microenvironment and exacerbates tissue damage. We further discuss the impact of inflammaging on major age-related pathologies, with a focus on the kidney as a paradigmatic model of age-related decline, where inflammaging and cellular senescence contribute to chronic kidney disease (CKD) and impaired regeneration. Finally, we summarize emerging therapeutic strategies such as senolytics, senomorphics, immunomodulation, and lifestyle interventions, aimed at reducing the burden of senescent cells, mitigating inflammaging and extending healthspan. Full article

Background: Dry eye disease (DED), characterized by tear film hyperosmolarity, can lead to corneal epithelial damage. The mechanisms linking hyperosmotic stress to human corneal epithelial cell (HCEPC) damage are not fully understood. Methods: A DED model was established by exposing HCEPCs to sustained hyperosmotic stress (400 mOsm/L) over multiple passages in vitro. Senescence was assessed using senescence-associated-β-galactosidase (SA-β-gal) staining, 5-ethynyl-2′-deoxyuridine (EdU) assays, p16^INK4A and senescence-associated secretory phenotypes (SASP) analysis. Mechanisms were investigated by measuring reactive oxygen species (ROS), mitochondrial function, energy metabolism, DNA damage, and inflammatory signaling. The role of autophagy was probed pharmacologically. Results: Hyperosmotic stress induced HCEPC senescence, driven by mitochondrial dysfunction, oxidative stress, DNA damage, bioenergetic crisis, and compromised autophagy (especially mitophagy). Autophagy and mitophagy play a key role in regulating senescence progression. Enhancing autophagy with LYN-1604 ameliorated oxidative stress, improved energy homeostasis, and attenuated senescence. Inhibiting autophagy exacerbated these states. Conclusion: Hyperosmolarity promotes HCEPC senescence via mitochondrial dysfunction and oxidative damage. Autophagy serves a critical protective role, and its enhancement represents a promising therapeutic strategy for DED. Full article

The vascular endothelium serves as a critical barrier preventing the transmigration of monocytes, circulating lipoproteins, and other molecules into the subendothelial space, and plays a vital role in regulating vascular tone. A dysfunctional and inflamed endothelial layer in response to disturbed blood flow or other proatherogenic risk factors is the initiating event in the pathogenesis of atherosclerosis, suggesting the importance of an intact and properly functioning endothelium in preventing the onset and progression of this disease. Accumulated evidence demonstrates the significant role of matricellular proteins, which are non-structural and secretory extracellular matrix (ECM) proteins, in the development of atherosclerosis. These proteins exert multifaceted effects on endothelial cells (ECs) ranging from reactive oxygen species (ROS) production, endoplasmic reticulum stress, and expression of adhesion molecules to autophagy and compromised barrier function via stimulating various molecular mechanisms. Given the critical roles of these processes in EC function and atherosclerosis, a better understanding of signaling pathways governed by matricellular proteins in ECs is required to develop therapeutic strategies for suppressing or preventing atherosclerosis and related cardiovascular diseases (CVDs). This review comprehensively summarizes the existing literature on the diverse roles of matricellular proteins in regulating EC inflammation and function, and highlights their potential as viable therapeutic targets for maintaining vascular health and inhibiting the progression of atherosclerosis. Full article

Extracellular vesicles (EVs) secreted by glioblastoma multiforme and other types of cancer cells are key factors contributing to the aggressiveness of the disease and its resistance to therapy. Chloroquine (CHQ), a lysosomal inhibitor, has shown potential as an enhancer of temozolomide (TMZ) cytotoxicity against glioblastoma cells. Since both CHQ and TMZ are known to modulate EV secretion, we sought to investigate their potential interplay in this process. Simultaneous treatment of TMZ-sensitive (U87-MG) and TMZ-resistant (U138-MG) glioblastoma cells with TMZ and CHQ led to a synergistic upregulation of EV secretion. Although CHQ did not enhance the TMZ cytotoxicity in U87-MG cells, it synergized with the latter to upregulate the release of extracellular nucleic acids implicating activation of unconventional secretory pathways. Synergistic upregulation of the autophagy markers LC3B-II and p62 by CHQ and TMZ in both cells and EVs indicates that secretory autophagy is likely involved in the observed unconventional secretion. Moreover, a significant enrichment of caveolin-1 in small EVs highlights their potential role in modulating tumor aggressiveness. The synergy in EV upregulation was not confined to the specific biological activity of TMZ and CHQ; similar effects were observed upon co-treatments with CHQ and etoposide (a topoisomerase inhibitor) and TMZ and Bafilomycin A1 (another lysosomal inhibitor). Heightened EV release was also observed in THP-1 monocytes and macrophages treated with Bafilomycin and TMZ, highlighting a broader, cell-type-independent mechanism. These findings indicate that combined DNA damage and lysosomal inhibition synergistically stimulate secretory autophagy and EV release, potentially impacting the tumor microenvironment and driving disease progression. Full article

Extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitors show therapeutic potential in triple-negative breast cancer (TNBC), but resistance through compensatory signaling limits their efficacy. We previously identified the secretory carrier membrane protein 3 (SCAMP3) as a regulator of TNBC progression and ERK1/2 activation. Here, we investigated the role of SCAMP3 in ERK1/2 signaling and therapeutic response using TMT-based LC-MS/MS phosphoproteomics of wild-type (WT) and SCAMP3 knockout (SC3KO) SUM-149 cells under basal conditions, after epidermal growth factor (EGF) stimulation, and during ERK1/2 inhibition with MK-8353. A total of 4408 phosphosites were quantified, with 1093 significantly changed. SC3KO abolished residual ERK activity under MK-8353 and affected the compensatory activation of oncogenic pathways observed in WT cells. SC3KO reduced the phosphorylation of ERK feedback regulators RAF proto-oncogene serine/threonine-protein kinase Raf-1 (S43) and the dual-specificity mitogen-activated protein kinase kinase 2 (MEK2) (T394), affected other ERK targets, including nucleoporins, transcription factors, and metabolic enzymes triosephosphate isomerase (TPI1) (S21) and ATP-citrate lyase (ACLY) (S455). SCAMP3 loss also impaired the mammalian target of rapamycin complex I (mTORC1) signaling and disrupted autophagic flux, evidenced by elevated sequestosome-1 (SQSTM1/p62) and microtubule-associated protein light chain 3 (LC3B-II) with reduced levels of the autophagosome lysosome maturation marker, Rab7A. Beyond ERK substrates, SC3KO affected phosphorylation events mediated by other kinases. These findings position SCAMP3 as a central coordinator of ERK signaling and autophagy. Our results support SCAMP3 as a potential therapeutic target to enhance ERK1/2 inhibitor clinical efficacy and overcome adaptive resistance mechanisms in TNBC. Full article

Neuropathic pain is a chronic condition driven by intertwined mechanisms of oxidative stress, inflammation, and cellular senescence. Nerve injury and metabolic stress elevate reactive oxygen and nitrogen species, disrupt mitochondrial function, and activate the DNA-damage response, which stabilizes p53 and induces p16/p21-mediated cell-cycle arrest. These events promote a senescence-associated secretory phenotype (SASP) rich in cytokines, chemokines, and prostanoids that amplify neuroimmune signaling. In the spinal dorsal horn and dorsal root ganglia, microglia and astroglia respond to redox imbalance and danger cues by engaging NF-κB and MAPK pathways, increasing COX-2–dependent prostaglandin synthesis, and releasing mediators such as IL-1β and BDNF that enhance synaptic transmission and reduce inhibitory tone through KCC2 dysfunction. At the periphery, persistent immune-glial cross-talk lowers activation thresholds of nociceptors and sustains ectopic firing, while impaired autophagy and mitophagy further exacerbate mitochondrial dysfunction and ROS production. Collectively, these processes establish a feed-forward loop in which redox imbalance triggers senescence programs and SASP, SASP perpetuates neuroinflammation, and neuroinflammation maintains central sensitization—thereby consolidating a self-sustaining redox–senescence–inflammatory circuit underlying neuropathic pain chronicity. Full article

Endometriosis is a chronic disease characterized by the ectopic presence of endometrial cells that evade apoptosis and survive and proliferate under harsh environmental conditions. It is closely associated with infertility and pregnancy-related complications. This review focuses on the molecular pathophysiology of endometriosis, particularly the disruption of the p53–AMPK–mTOR signaling axis, and highlights the dysregulation of decidualization and cellular senescence, incorporating recent findings in reproductive physiology. A comprehensive literature search was conducted using PubMed and Google Scholar without temporal restrictions. Endometriotic cells adapt to the hostile peritoneal environment through resistance to apoptosis and alterations in autophagy. In the early stages, autophagy activation may promote cell survival; however, as the disease progresses, autophagic activity tends to decline. Aberrant activation of mTOR signaling is implicated in this process, contributing to the suppression of autophagy, impaired decidualization, and promotion of cellular senescence, ultimately facilitating lesion progression and infertility. Indeed, in the eutopic endometrium of patients with endometriosis, progesterone resistance, elevated inflammatory cytokines, and epigenetic abnormalities are known to reduce endometrial receptivity. Moreover, suppression of autophagy leads to excessive cellular senescence and secretion of the senescence-associated secretory phenotype (SASP), thereby interfering with proper decidualization. Maintaining an appropriate balance between decidualization and cellular senescence is essential for reproductive function. Future development of therapeutic strategies targeting these processes is expected to help overcome infertility associated with endometriosis. Full article

Alzheimer’s disease, a neurodegenerative brain disorder leading to the progressive decline in cognitive functions, is the most common type of dementia. The main risk factor for its development is aging. Recent studies indicate that cellular senescence mechanisms are among the major factors in a heterogeneous aging process. Cellular senescence is characterized by a permanent proliferative arrest. Many factors might initiate senescence, for example, damage of DNA, shortening of telomeres, dysfunction of mitochondria, and oncogene activation. These processes lead to alterations in the morphology and function of senescent cells. Research is still ongoing to identify one universal marker that could detect senescent cells and distinguish them from other non-proliferating cells. Those cells are involved in age-related pathologies through many heterogeneous processes, including secretion of pro-inflammatory senescence-associated secretory phenotype factors, which affect the brain differently. Alzheimer’s disease is an example of a neurodegenerative condition connected to cellular senescence. Senescent cells have been demonstrated to accumulate near Aβ plaques and neurofibrillary tangles. In this review, the multifactorial connection between Alzheimer’s disease and cellular senescence is discussed, including topics such as senescence of astrocytes, defective mitochondria, dysregulation of cellular autophagy, and the role of senescent microglia. Full article