Search Results (258)

Background: Tumor hypoxia in non-small cell lung cancer (NSCLC) promotes malignant progression and treatment resistance by enhancing abnormal vasculature, invasiveness, and metastasis. However, the molecular mechanisms underlying hypoxia-driven tumor progression remain incompletely understood. Methods: In this study, patient samples, cell lines, single-cell transcriptomic data, and spatial transcriptomic data were comprehensively analyzed to investigate hypoxia-associated molecular alterations in NSCLC. Results: A global trend toward shortened 3’ untranslated regions (3’UTRs) was observed in hypoxic tumors. Analysis of hypoxia-related alternative polyadenylation (APA) events revealed preferential usage of proximal polyadenylation sites (poly(A) sites, PASs) in CARM1. Shortening of the CARM1 3’UTR was associated with hypoxia and may serve as a candidate biomarker. This APA event may reduce putative microRNA (miRNA) binding sites and contribute to increased CARM1 expression, while potentially influencing the expression of hypoxia-related genes such as SELENBP1. Drug sensitivity analysis further suggested that patients with shorter CARM1 3’UTRs may exhibit differential responses to cisplatin chemotherapy. Moreover, single-cell and spatial transcriptomic analyses demonstrated enhanced interactions between hypoxic tumor cells and fibroblasts, highlighting a potential role for APA in remodeling the hypoxic tumor microenvironment. Conclusions: Our findings identify hypoxia-related APA features and characterize hypoxia-associated alterations within the NSCLC tumor microenvironmen, providing new insights into the molecular landscape of hypoxia-associated tumor progression. Full article

The hypoxic microenvironment plays a critical role in the progression of canine osteosarcoma (OSA) by promoting different cellular responses, including the release of extracellular vesicles (EVs). Given the clinical aggressiveness of canine OSA, the aim of this study was to evaluate the miRNAome profile in EVs released in vitro by four canine OSA cell lines under hypoxic conditions. In particular, for this study we used two commercial canine osteosarcoma cell lines (D17 and D22) and two primary osteosarcoma cell lines obtained in our laboratory (Penny and Wall). D17, D22, Penny, and Wall cell lines were cultured under normoxic and hypoxic conditions (200 µM CoCl₂) for 24 h. EVs were isolated by size-exclusion chromatography and characterized by nanoparticle tracking analysis and Western blotting. miRNAs extracted from EVs were then sequenced and analyzed using bioinformatics approaches. The most representative miRNAs were identified and validated by qPCR using the miRCURY LNA miRNA PCR assay. miRNome profiling identified 233 miRNAs differentially expressed in EVs across all analyzed cell lines. Among these, 94 miRNAs were detected exclusively under hypoxic conditions. From this subset, 43 miRNAs were selected for further validation by qPCR. The qPCR results showed that miR-222-3p and miR-186-5p were significantly downregulated in the Wall cell line under hypoxia (p ≤ 0.05). TargetScan and pathway enrichment analyses demonstrated that miR-186-5p regulates target genes involved in different cellular processes. In human osteosarcoma, low serum levels of miR-222-3p are associated with poor prognosis, while miR-186-5p is recognized as a key hypoxia-responsive miRNA. Collectively, these results suggest the potential of EV-associated miRNAs as biomarkers in canine OSA and support their relevance in translational and comparative oncology. Full article

Transarterial chemoembolization (TACE) is the standard treatment for patients with intermediate-stage hepatocellular carcinoma (HCC), yet nearly half of treated patients fail to achieve durable benefit, and reliable biomarkers enabling early therapeutic stratification are still lacking. Treatment response is typically assessed by imaging one month after TACE and at three-month intervals, potentially delaying timely access to alternative therapies in non-responding patients. Circulating microRNAs (miRNAs) represent promising biomarkers due to their stability in body fluids and ease of detection. Here, we evaluated circulating miR-22 as an early predictor of TACE non-responder status and as a mechanistically relevant therapeutic target. Circulating miR-22 levels were measured by microarray and quantitative RT–PCR in three independent cohorts of early-to-intermediate-stage HCC patients undergoing TACE. Circulating miR-22 increased significantly in non-responders as early as 48 h after treatment, and fold changes consistently predicted treatment failure across two independent validation cohorts. Mechanistically, we identified the G2/M checkpoint kinase WEE1 as a direct functional target of miR-22. Modulation of the miR-22/WEE1 axis affected cell-cycle progression, proliferation, apoptosis, and DNA damage response in HCC cell lines and xenograft models. Under hypoxia-mimicking conditions combined with doxorubicin exposure, pharmacological inhibition of WEE1 induced mitotic catastrophe in highly proliferative miR-22-silenced cells. Collectively, these findings identify early post-TACE elevation of circulating miR-22 as a biomarker of non-response and highlight the miR-22/WEE1 axis as a potential target for precision treatment strategies in HCC. Full article

Urban micro-tidal canals frequently suffer from severe hypoxia due to restricted hydrodynamic exchange and untreated discharges. Field monitoring during a 2022 mass fish mortality event at the Dongsam tidal canal revealed that during the ‘tidal window gap’—a hydraulic stagnation period required for passive tidal flushing—bottom-layer dissolved oxygen (DO) plummeted to a lethal 0.44 mg/L. To address the limitations of passive tidal exchange, this study proposes a conceptual hybrid water purification framework integrating active ecological interventions: wall-mounted spiral flow aeration for continuous oxygenation and vertical bio-curtains for pollutant interception. By synergizing fluid mechanics with ecological engineering, core design parameters were systematically derived: an effective mixing width ($W_{eff}=2.2 h$), longitudinal spacing ($L_s$ = 13.6$\times W_{eff}$), an optimal root immersion ratio ($D_r/h$ = 0.6), and climate-adaptive planting densities (${\rho }_p\approx$12–32 plants/m²). Additionally, a corrosion-resistant FRP guide rail system was incorporated to facilitate autonomous adaptation to tidal fluctuations. The framework was conceptualized through a prototype design for the Dongsam canal and subsequently scaled to 15 international micro-tidal canals across diverse climatic zones. The optimized bilateral staggered configuration established a continuous 528 m² ecological refuge, ensuring DO levels recover above the critical 3 mg/L threshold. Ultimately, this research presents a comprehensive methodological framework and a flexible engineering toolkit to guide water quality and ecological resilience enhancements in shallow urban waterways worldwide. Full article

Chronic lung allograft dysfunction (CLAD) remains the principal limitation to long-term survival after lung transplantation (LT). Early molecular alterations within the graft may precede clinically overt functional decline, but their biological significance remains incompletely defined. In this single-center exploratory pilot study, 16 bilateral lung transplant recipients underwent bronchoalveolar lavage (BAL) sampling at 7 days, 15 days, and 3 months post-transplantation. BAL-derived microRNA (miRNA) profiles were analyzed longitudinally and correlated with long-term clinical outcomes, including CLAD development and phenotypic classification into bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS), over extended follow-up (mean 98 months). Distinct early miRNA signatures were detectable within the first weeks after transplantation and were associated with divergent long-term clinical trajectories. Specific miRNAs, namely let-7e-5p and miR-30d-3p, were associated with subsequent CLAD, whereas differential expression patterns distinguished trajectories toward BOS or RAS. Enrichment analyses highlighted networks related to innate immune activation, hypoxia, tissue remodeling, and PI3K–mTOR signaling. Notably, the occurrence of acute rejection did not differ significantly between patients who developed CLAD and those who remained stable. These findings, although preliminary, suggest that early BAL-derived miRNA profiles may reflect biologically distinct graft states associated with long-term CLAD phenotypes. Full article

Hypoxia-dependent microRNAs play an important role in orchestrating a plant’s response to low-oxygen stress. To assess the regulatory mechanisms of the adaptive response of maize (Zea mays L.) to hypoxia, an antisense sequence was developed, and the short tandem target mimic (STTM) system was used to induce the loss of function of the mature microRNA775A (miR775a) in maize. A recombinant binary vector pBI121 cloned in E. coli cells containing the antisense sequence anti-miR775A to maize miR775A was acquired to create a line of modified A. tumefaciens EHA105. Using the puncturing method on soaked seeds, maize plants with an active anti-miR775A construct were obtained, as evidenced by a decrease of more than 10-fold in mature miR775A content and by developmental changes in the seedlings. The size of seedlings of the maize knockdown line was almost twice smaller than that of the wild-type (WT) plants. An assessment of the effects of hypoxic conditions induced by flooding of 14-day-old maize plants revealed differences in the expression and activity of several enzymes between WT and knockdown plants. The reduced miR775A levels led to a 2.1-fold drop in pyruvate levels, which resulted in decreased pyruvate kinase, pyruvate dehydrogenase, and lactate dehydrogenase activities as compared to WT plants. A decrease in miR775A content in the maize knockdown cell line also affected the function of mitochondrial and extramitochondrial isoenzymes of citrate synthase, aconitase, and fumarase under hypoxic conditions. Full article

A revised two-stage model of preeclampsia is proposed, centering on an autophagy-dependent requirement for extravillous trophoblast entry into the proximal one-third of the myometrium. The One-Third Myometrium Enigma, introduced here, denotes the unresolved physiological rule that early placentation requires trophoblasts to traverse decidua and reach the proximal one-third of myometrium under hypoxia and nutrient scarcity. The hypothesis posits a timed rise in basal autophagy to sustain trophoblast energy homeostasis and invasion, accompanied by TFEB-driven lysosomal programs that enable villous cytotrophoblast syncytialization. Autophagic dysfunction could contribute to shallow invasion, chronic placental hypoxia, fetal growth restriction, and release of placental injury signals preceding maternal syndrome. Potential failure modes include reduced autophagic flux due to inhibition of autophagosome to lysosome fusion or mistimed persistence of hypoxia signaling, such as prolonged HIF-1α activity. Collectively, this evidence suggests that impaired autophagy is a testable contributor to preeclampsia pathogenesis. Predictions include early risk stratification with circulating autophagy markers and extracellular vesicle microRNAs, and therapeutic benefit from autophagy modulation that targets AMPK or mTOR or activates TFEB with safety constraints. This framework reframes preeclampsia as a disorder of placental quality control and specifies where and when autophagy may be required. Full article

Oncometabolites and hypoxia-regulated exosomes orchestrate hypoxia-inducible factor (HIF)–driven macrophage reprogramming across chronic cardiometabolic and oncologic conditions. In type 2 diabetes (T2D) and obesity, regional hypoxia in expanding white adipose tissue (WAT) reconfigures macrophage immunometabolism and chemokine signaling, recruits C-C chemokine receptor 2 (CCR2⁺) monocytes, and skews adipose-tissue macrophages toward M1-like programs that sustain low-grade inflammation and blunt the physiological M1-to-M2 transition during wound repair. In atherosclerotic plaques, lipid-core hypoxia stabilizes HIF-1α, amplifies nuclear factor kappa-light-chain-enhancer of activated B cells/reactive oxygen species (NF-κB/ROS) signaling, increases matrix metalloproteinase-2/-9 (MMP-2/-9) release, and reduces ATP-binding cassette transporter A1 (ABCA1)-mediated cholesterol efflux, weakening the fibrous cap. In tumors, poorly perfused niches accumulate lactate and succinate, which act as paracrine cues. Lactate activates PKA/cAMP pathways and promotes immunosuppressive tumor-associated macrophages (TAMs), whereas succinate signals through succinate receptor 1 (SUCNR1) to reinforce HIF-1α–dependent transcription and M2-like programming. In parallel, hypoxia-regulated exosomes deliver microRNAs such as miR-301a-3p, which suppress phosphatase and tensin homolog (PTEN) and activate PI3Kγ, thereby augmenting immunosuppression and programmed death-ligand 1 (PD-L1) expression. Clinically, this hypoxia–oncometabolite–exosome triad links oxygen debt with macrophage state, plaque destabilization, impaired wound repair, and tumor immune escape. Translational entry points include selective HIF-2α inhibition, phosphoinositide 3-kinase gamma (PI3Kγ) blockade, SUCNR1 targeting, and exosome-based miRNA modulation, while a biomarker panel comprising HIF-1α, vascular endothelial growth factor A (VEGF-A), and MMP-9 offers a pragmatic readout of hypoxia burden, macrophage programming, and therapeutic response. We conducted a focused narrative review (PubMed, Scopus, Web of Science; English; 2003–2025), prioritizing mechanistic and translational studies on hypoxia–HIF, lactate/succinate, and hypoxia-regulated exosomes across T2D, atherosclerosis, and cancer. Full article

Myocardial ischemia–reperfusion injury remains a major unresolved challenge in cardiovascular medicine. Although timely restoration of blood flow is essential to limit ischemic damage, reperfusion triggers a complex network of maladaptive biological responses, including oxidative stress, calcium overload, mitochondrial dysfunction, metabolic impairment, and sterile inflammation. These processes converge on cardiomyocyte death, adverse ventricular remodeling, and long-term functional deterioration. Mesenchymal stem cells have been widely investigated as cardioprotective agents; however, accumulating evidence indicates that their beneficial effects are predominantly mediated by paracrine mechanisms. Among these, extracellular vesicles released by mesenchymal stem cells have emerged as key biological effectors. Experimental studies demonstrate that mesenchymal stem cell–derived extracellular vesicles modulate multiple signaling pathways involved in ischemia–reperfusion injury, including activation of the phosphoinositide 3-kinase (PI3K) and protein kinase B (PKB) axis, regulation of signal transducer and activator of transcription 3 (STAT3) signaling in a cell-specific manner, suppression of nuclear factor kappa B (NF-κB)-driven inflammatory responses, and stabilization of hypoxia-inducible factor-1α (HIF-1α)–dependent adaptive programs. At the subcellular level, these vesicles preserve mitochondrial structure and function, support energy metabolism, regulate mitophagy, and limit oxidative damage. Their molecular cargo, comprising regulatory microRNAs, metabolic enzymes, and stress-response proteins, enables coordinated modulation of survival, inflammatory, and reparative pathways rather than single-target effects. This review synthesizes current experimental evidence on the mechanistic basis of mesenchymal stem cell–derived extracellular vesicle–mediated cardioprotection and discusses their potential as cell-free, mechanism-based therapeutic strategies to limit myocardial ischemia–reperfusion injury. Full article

Herpes simplex keratitis (HSK) is classically described as an immunopathological disease driven by recurrent herpes simplex virus type 1 (HSV-1) infection and chronic inflammation. So far, immune-mediated tissue damage has not fully explained the molecular mechanisms governing disease progression toward corneal neovascularization (CNV), a major cause of corneal blindness and vision loss worldwide. Increasing evidence indicates that CNV results from complex interactions that extend beyond leukocyte-driven inflammation, as the host cell machinery, including key pathways and molecular markers, is hijacked by the invading virus to establish and perpetuate replication and lifelong latency. These host–cell interactions regulate angiogenic imbalance, vascular privilege, and tissue remodeling, which collectively promote pathological vascular invasion. This review re-examines HSK by focusing on molecular mechanistic pathways and drivers that regulate disease progression towards CNV, upstream of immune response drivers. Specifically, we discuss the roles of endothelial growth factors, matrix metalloproteinases, Heparanase, and Syndecan-1 signaling, as well as microRNA-mediated regulation, and key signaling axes, including JAK2/STAT3, PI3K/AKT/mTOR, and hypoxia signaling. By integrating these pathways and molecular markers, we propose an updated mechanistic framework, including a conceptual model for the underexplored role of heparanase, and identify pathway-level targets with potential therapeutic relevance for HSK-associated CNV. Full article

Myocardial infarction (MI) triggers complex pathological processes, including inflammation, hypoxia, and fibrotic remodeling. MicroRNAs (miRNAs) have emerged as promising biomarkers for cardiovascular injury; however, their expression dynamics along processes remain underexplored. We used an in vivo rat model of permanent coronary occlusion to study the molecular alterations associated with MI and its resolution in a temporal mode, including five experimental groups with five animals in each: sham, PO 24 h, PO 72 h, PO 7 d, PO 1 month. Histological analysis, serum biomarkers, and miRNA/gene expression profiles were analyzed in a time-dependent manner post-occlusion. Subsequent analysis revealed early depletion of selected circulating miRNAs (PO 24 h). Transient upregulation in cardiac tissue miRNAs, inflammatory and fibrotic gene expression (Fibronectin, Collagen, Vimentin, E-Cadherin) were observed at PO 72 h. These molecular alterations correlated with histological evidence of myocardial injury and repair. Taken together, our findings delineate the molecular timeline of MI progression and resolution and identify candidate miRNAs as sensitive and time-dependent indicators of myocardial stress, including miR-107, miR-122-5p and miR-221-3p. This integrative approach supports the use of miRNA signatures for noninvasive monitoring of cardiac injury and resolution and unveils potential therapeutic targets to reduce pathological remodeling. Full article

Long COVID-19 syndrome (or so-called post-COVID-19) is indicated by miscellaneous symptoms, usually starting 3 months from the COVID-19 infection and lasting for at least 2 months, which cannot be explained by an alternative diagnosis. There has been more and more reports addressing the audiovestibular dysfunction related to long COVID-19 syndrome. Emerging evidence suggests that the linkage between audiovestibular dysfunction and long COVID-19 syndrome might rely on (a) direct inner ear system damage related to viral invasion and consequent inflammation, (b) micro thromboembolic events, which might result from the COVID-19-induced autoimmune reaction against endothelial cells, and consequent transient-ischemia and hypoxia of the auditory pathways, (c) the disturbed nerve conduction in vestibulocochlear nerves due to viral invasion, and finally (d) altered auditory cortex function, either imbalanced central gain or neurotransmitter disturbance. However, most of the aforementioned mechanism remained hypothetic and still needed further studies to approve or refute. This systematic review synthesizes current evidence on the characteristics, pathophysiology, diagnostic approaches, and management of audiovestibular dysfunction related to long COVID-19 syndrome. Literature searches across PubMed, Embase, ClinicalKey, Web of Science, and ScienceDirect (up to 15 December 2025) were conducted in accordance with PRISMA guidelines. Through this systematic review, we provided a schematic diagram of the physiopathology of long COVID-19 syndrome-related audiovestibular dysfunction. Further, we summarized the currently available diagnostic tools to explore the audiovestibular function in such patients. The currently available treatment, either pharmacotherapy or nonpharmacotherapy, mainly tackles idiopathic audiovestibular dysfunction but not specifically long COVID-19 syndrome-related audiovestibular dysfunction. Timely recognition and intervention may prevent progression to permanent hearing loss or vestibular disability, improving quality of life. Trial registration: PROSPERO CRD420251265741. Full article

Lung cancer remains a major public health challenge due to high incidence and mortality. The chemokine receptor CXCR4 and its ligand CXCL12 (SDF-1) constitute a critical axis in tumor biology, influencing tumor cell proliferation, invasion, angiogenesis, and immune evasion. Aberrant CXCR4 expression is frequently observed in lung cancer and is closely associated with adverse prognosis, enhanced metastatic potential, and therapeutic resistance. Mechanistically, CXCR4 activates signaling pathways including PI3K/AKT, MAPK/ERK, JAK/STAT, and FAK/Src, promoting epithelial–mesenchymal transition, stemness, and survival. The CXCL12/CXCR4 axis also orchestrates interactions with the tumor microenvironment, facilitating chemotaxis toward CXCL12-rich niches (e.g., bone marrow and brain) and modulating anti-tumor immunity via regulatory cells. Regulation of CXCR4 occurs at transcriptional, epigenetic, and post-transcriptional levels, with modulation by hypoxia, inflammatory signals, microRNAs, and post-translational modifications. Clinically, high CXCR4 expression correlates with metastasis, poor prognosis, and reduced response to certain therapies, underscoring its potential as a prognostic biomarker and therapeutic target. Therapeutic strategies targeting CXCR4 include small-molecule antagonists (e.g., AMD3100/plerixafor; balixafortide), anti-CXCR4 antibodies, and CXCL12 decoys, as well as imaging probes for patient selection and response monitoring (e.g., 68Ga-pentixafor PET). Preclinical and early clinical studies suggest that CXCR4 blockade can impair tumor growth, limit metastatic spread, and enhance chemotherapy and immunotherapy efficacy, although hematopoietic side effects and infection risk necessitate careful therapeutic design. This review synthesizes the molecular features, regulatory networks, and translational potential of CXCR4 in lung cancer and discusses future directions for precision therapy and biomarker-guided intervention. Full article

Background/Objectives: Nonunion bone healing results from a critical size defect that fails to bridge a bone injury to produce bony union. Novel approaches are critical for refining therapy in clinically challenging bone injuries, but the complex and coordinated nature of fracture callus tissue development requires study outside of the simple closed murine fracture model. Methods: We have utilized a three-dimensional printing approach to develop a scaffold construct with layers designed to sequentially release small molecule therapy within the tissues of a murine endochondral segmental defect to augment different mechanisms of fracture repair during critical stages of nonunion bone healing. Initially, a sonic hedgehog (SHH) agonist is released from a fibrin layer to promote chondrogenesis. A prolyl-hydroxylase domain (PHD)2 inhibitor is subsequently released from a β-tricalcium phosphate (β-TCP) layer to promote hypoxia-inducible factor (HIF)-1α regulation of angiogenesis. This sequential approach to therapy delivery is assisted by the inclusion of bone marrow stromal cells (BMSCs) to increase the cell substrate available for the small molecule therapy. Results: Immunohistochemistry of fracture callus tissue revealed increased expression of PTCH1 and HIF1α, targets of hedgehog and hypoxia signaling pathways, respectively, in the SAG21k/IOX2-treated mice compared to vehicle control. MicroCT and histology analyses showed increased bone in the fracture callus of mice that received therapy compared to control vehicle scaffolds. Conclusions: While our findings establish feasibility for the use of BMSCs and small molecules in the fibrin gel/β-TCP scaffolds to promote new bone formation for segmental defect healing, further optimization of these approaches is required to develop a fracture callus capable of completing bony union in a large defect. Full article

Diabetic wounds remain chronically non-healing due to impaired angiogenesis, persistent inflammation, and defective extracellular matrix remodelling. In recent years, stem cell-derived exosomes have emerged as a potent cell-free regenerative strategy capable of recapitulating the therapeutic benefits of mesenchymal stem cells while avoiding risks associated with direct cell transplantation. This review critically evaluates the preclinical evidence supporting the use of exosomes derived from adipose tissue, bone marrow, umbilical cord, and induced pluripotent stem cells for diabetic wound repair. These exosomes deliver bioactive cargos such as microRNAs, proteins, lipids, and cytokines that modulate key signalling pathways, including Phosphatidylinositol 3-kinase/Protein kinase (PI3K/Akt), Nuclear factor kappa B (NF-κB), Mitogen-activated protein kinase (MAPK), Transforming growth factor-beta (TGF-β/Smad), and Hypoxia inducible factor-1α/Vascular endothelial growth factor (HIF-1α/VEGF), thereby promoting angiogenesis, accelerating fibroblast and keratinocyte proliferation, facilitating re-epithelialization, and restoring immune balance through M2 macrophage polarization. A central focus of this review is the recent advances in exosome-based delivery systems, including hydrogels, microneedles, 3D scaffolds, and decellularized extracellular matrix composites, which significantly enhance exosome stability, retention, and targeted release at wound sites. Comparative insights between stem cell therapy and exosome therapy highlight the superior safety, scalability, and regulatory advantages of exosome-based approaches. We also summarize progress in exosome engineering, manufacturing, quality control, and ongoing clinical investigations, along with challenges related to standardization, dosage, and translational readiness. Collectively, this review provides a comprehensive mechanistic and translational framework that positions stem cell-derived exosomes as a next-generation, cell-free regenerative strategy with the potential to overcome current therapeutic limitations and redefine clinical management of diabetic wound healing. Full article