Search Results (2,000)

Exosomes are small extracellular vesicles (EVs) generated through the endosomal pathway that mediate intercellular communication by transferring proteins, lipids, and regulatory RNAs. In parallel, the NLRP3 inflammasome is a key signaling platform of the innate immune system that integrates cellular stress signals to drive inflammatory responses. Recent studies suggest that exosome biology and NLRP3 signaling intersect at fundamental levels of cell organization. On one hand, inflammasome activation can promote exosome biogenesis and secretion through caspase-1-dependent remodeling of intracellular trafficking, including cleavage of Rab-interacting lysosomal protein (RILP) and redistribution of multivesicular bodies (MVBs). These processes influence the selective loading of exosomal cargo, notably miRNAs, through sequence-dependent mechanisms involving RNA-binding proteins and the endosomal sorting machinery. Conversely, exosomes can modulate inflammasome activity in recipient cells by delivering regulatory molecules that affect NLRP3 priming and signaling. Although exosome release is increased in several inflammatory disorders, including ischemia/reperfusion injury, diabetes and neurodegenerative disease, the mechanistic relationship between exosome pathways and NLRP3 remains incompletely understood. In addition to their pathogenic and diagnostic relevance, exosomes are increasingly being explored as innovative acellular biologics and therapeutic delivery platforms due to their immunomodulatory and regenerative properties. In particular, mesenchymal stem cell (MSC)-derived exosomes have shown promising anti-inflammatory effects through modulation of NLRP3 pathways in preclinical models of kidney, cardiovascular, neurological and inflammatory diseases. Here, we review current evidence connecting NLRP3 inflammasome activation to EV trafficking, exosome formation, and cargo selection, and discuss how exosome-mediated communication shapes inflammasome signaling across cells and tissues in health and disease. Full article

Background/Objectives: Aging is a major risk factor that exacerbates acute kidney injury (AKI) and subsequent renal fibrosis. However, age-related factors contributing to post-AKI fibrotic remodeling remain underexplored. This study aimed to investigate the protective potential of apelin, an endogenous peptide, in mitigating post-AKI renal fibrosis in aged mice. Methods: A mouse model of AKI was established in 8-week-old and 19-month-old male C57BL/6 mice by clamping the left renal artery for 40 min, followed by reperfusion and euthanasia 2 weeks post-ischemia. To evaluate the protective effect of apelin pretreatment, the 19m-APLN group received intraperitoneal apelin administration (25 μg/kg/day) for 2 weeks prior to AKI induction. The effects of apelin on renal fibrosis were evaluated using renal function tests (blood urea nitrogen, serum creatinine levels), histological analysis, and Western blotting. Results: The 19m-AKI group exhibited more severe renal damage and interstitial fibrosis, along with a marked reduction in apelin and APLNR expression compared to the 8wk-AKI group. Apelin-13 pretreatment attenuated renal injury and fibrotic remodeling in aged mice, with reduced collagen deposition accompanied by lower pro-TGF-β1 expression and SMAD3 phosphorylation. Conclusions: These results highlight the protective role of apelin against age-related exacerbation of post-AKI renal fibrosis, suggesting that prophylactic Apelin-13 administration may attenuate post-I/R renal injury and fibrotic remodeling in aged kidneys. Full article

Hepatic ischemia–reperfusion injury (HIRI) is not only a common complication of liver transplantation and major hepatic surgery but also a critical determinant of postoperative prognosis. Lactate metabolic reprogramming has been observed in HIRI, yet the role of lactate and its related lactylation in the pathogenesis of HIRI remains unclear. To address this, we integrated single-cell and bulk RNA-seq data with multiple bioinformatic approaches. Five single-cell gene set activity scoring methods (AUCell, UCell, singscore, ssGSEA, and AddModuleScore) were applied to evaluate lactylation activity across cell types, followed by differentially expressed gene (DEG) analysis and high-dimensional Weighted Correlation Network Analysis (hdWGCNA) to identify lactylation-associated genes. Five machine learning algorithms (Random Forest, Boruta, LASSO, GBM, and Decision Tree) were used to screen optimal feature genes, with SHAP analysis further explaining their importance. Bulk RNA sequencing data from the Gene Expression Omnibus (GEO) database were used for validation. Furthermore, NR4A3-related inhibitors were screened using the ChEMBL online tool and assessed by docking and molecular dynamic simulation. We observed significant heterogeneity in lactate metabolism activity across cell types in hepatic ischemia–reperfusion injury (HIRI), with higher activity levels observed for hepatocytes and mononuclear phagocytes. The integration of SHAP and machine learning identified PFKFB3, ZYX, and NR4A3 as closely associated with high lactylation after HIRI, and cross-analysis with bulk RNA data confirmed their consistent upregulation. Candidate gene expression was experimentally validated in a murine liver IRI model through Western blotting and RT-qPCR. Although lactylation has been previously reported in HIRI, this study’s unique contribution is to reveal the cell-type heterogeneity of lactylation-related gene expression at the single-cell level through multi-omics integration and machine learning. The identification of NR4A3, PFKFB3, and ZYX as lactylation-associated regulators proposes novel therapeutic targets for improving graft survival in liver transplantation. Full article

Ischemia–reperfusion injury (IRI) is a common form of tissue injury encountered in myocardial infarction, ischemic stroke, solid-organ transplantation, and complex vascular surgery. Timely restoration of blood flow is essential for salvaging ischemic tissues; however, reperfusion itself can induce sterile inflammation and oxidative stress, further compromising microvascular and organ function. Accumulating evidence indicates that alterations in the local microenvironment associated with innate immune responses contribute to this pathological process, with neutrophils representing among the earliest effector cells recruited to injured tissues. In response to danger signals such as damage-associated molecular patterns, neutrophils can release neutrophil extracellular traps (NETs), extracellular web-like structures composed of decondensed chromatin and granular proteins. Extracellular NETs can injure endothelial and parenchymal cells and provide procoagulant scaffolds that contribute to immunothrombosis and local inflammatory responses. Current evidence is derived predominantly from clinical samples and experimental models across different organs. Owing to organ-specific differences in microvascular architecture, cellular composition, and ischemia–reperfusion conditions, the triggers, relative pathological contributions, and responses to NET-targeted interventions are not uniform across tissues. This review first summarizes the intracellular events preceding NET release, the molecular composition of extracellular NETs, and the mechanisms of NET extrusion. We then provide an organ-based synthesis of the local triggers, major injurious effects, and interventional evidence for NETs in the heart, liver, lung, kidney, brain, intestine, limb, and skin, while discussing recurrent pathological features—including microthrombosis, endothelial or barrier injury, and inflammatory amplification—in the context of organ-specific differences and the limitations of the available evidence. In addition, we evaluate therapeutic strategies involving degradation of extracellular NETs and neutralization of their toxic components, inhibition of NET-associated enzymes and upstream signaling pathways, and spatiotemporally targeted delivery, together with the major barriers to clinical translation. Overall, this review provides an organ-structured synthesis of current evidence linking NETs to IRI and offers a framework for understanding their context-dependent pathological roles and for developing organ- and phase-specific therapeutic strategies. Full article

To quantitatively characterize the pharmacokinetic and pharmacodynamic interactions between Hydroxysafflor Yellow A (HSYA) and Calycosin (CA) in cerebral ischemia–reperfusion injury (CIRI), a factorial experimental design was combined with a hierarchical coupled PK-PD modeling framework. The coupled PK model adequately described the concentration-time profiles of HSYA and CA under co-administration, with R² values of 0.83 and 0.86, respectively, while the PK-PD model showed good fitting performance for Caspase-3 and HIF-1α, with all R² values exceeding 0.97. Structural identifiability analysis showed that the newly introduced PK and PD coupling parameters were globally identifiable, and their Bootstrap 95% confidence intervals excluded zero. After Holm-Bonferroni correction, AUC_0-t, AUC_0-∞ and CL differed significantly between single and combined administration, whereas MRT did not. The model-derived relative contribution weights of HSYA and CA were quantified for both Caspase-3 and HIF-1α, with uncertainty assessed using Bootstrap 95% confidence intervals. Overall, the proposed coupled PK-PD framework provides a quantitative approach for characterizing component interactions and relative pharmacodynamic contributions in multi-component systems. Full article

Although the prevalence of acute kidney injury and chronic kidney disease remains high and effective therapeutic targets remain scarce, significant progress has been made in recent years across the following major directions: G2/M phase cell cycle arrest, DNA damage, mitochondrial dysfunction, hypoxia-inducible factor signaling, dysregulated autophagy, and epigenetic alterations. RGC-32 is abundantly expressed in all tubular segments of normal renal tissues and is primarily localized to the cytoplasm and perinuclear region of renal tubular epithelial cells. Moreover, RGC-32 is involved in cell cycle regulation as well as cell proliferation and differentiation. To explore the functional role of RGC-32 in renal repair after acute ischemia–reperfusion injury, we utilized CRISPR-Cas9 technology combined with Cre/loxP recombination to generate a novel, renal tubule-specific RGC-32 knockout mouse model and systematically characterized its phenotype. Our findings demonstrate that renal tubule-specific RGC-32 deficiency does not impair normal growth or baseline renal function but alters the distribution of peripheral blood T lymphocyte subsets; whether this alteration contributes to renal immune regulation remains to be determined by future functional studies. More importantly, upon IRI, RGC-32 knockout in renal tubules leads to significantly aggravated renal dysfunction, elevated injury markers, and a possible association with enhanced chronic fibrosis. Full article

Cardiovascular diseases remain a major cause of death and disability, and the limited regenerative capacity of the adult myocardium continues to constrain recovery after myocardial infarction, ischemia/reperfusion injury, cardiomyopathy, and heart failure. Small extracellular vesicles (sEVs), often described as exosome-enriched vesicle preparations, have emerged as promising cell-free mediators of cardioprotection and cardiac repair. This review evaluates the current experimental and translational evidence on sEVs in cardiac injury, including regulatory RNA and non-RNA cargo mechanisms, producer cell sources, preclinical injury models, engineered and biomaterial-assisted delivery strategies, and the development of clinically viable cell-free therapies. Across preclinical models, sEVs derived from mesenchymal stem cells, induced pluripotent stem cell-derived cardiac cells, cardiac progenitor cells, endothelial cells, cardiomyocytes, immune cells, and other sources have been associated with improved ventricular function, reduced infarct or scar size, enhanced angiogenesis, lower apoptosis, attenuated fibrosis, and modulation of post-injury inflammation. These effects are frequently associated with changes in, or enrichment of, microRNAs, long non-coding RNAs, and circular RNAs that regulate survival signaling, immune polarization, extracellular matrix remodeling, and endothelial recovery. Emerging evidence further suggests that proteins, lipids, and organelle-associated cargo, including mitochondrial components, also contribute to stress adaptation, vesicle biogenesis, mitochondrial homeostasis, and metabolic repair. However, the field remains limited by inconsistent nomenclature, variable isolation and characterization methods, heterogeneous producer cell sources, uncertain potency assays, incomplete biodistribution data, and unresolved regulatory classification. Overall, sEV-based therapy represents a compelling but still developing approach to cardiac repair. Within this framework, functional recovery is treated as an outcome of cardioprotection, cardiac repair, or, where supported, myocardial regeneration; regeneration is reserved for evidence of newly formed and functionally integrated myocardium. Future progress will depend on better product definition, mechanism-linked potency testing, scalable manufacturing, and delivery strategies matched to specific cardiac indications. Full article

Hepatic ischemia–reperfusion injury (IRI) is a major clinical challenge in liver surgery and transplantation, contributing to postoperative complications and graft dysfunction. The pathogenesis of hepatic IRI is complex and multifactorial, involving ischemia-induced metabolic consequences, oxidative stress, inflammatory responses, endothelial dysfunction, and the activation of immune pathways upon reperfusion. Despite extensive research efforts, the translation of preclinical findings into effective clinical interventions remains limited. This review provides a critical overview of the principal models used to investigate hepatic IRI. Conventional two-dimensional in vitro systems, including monoculture and co-culture models, offer controlled environments for mechanistic studies and high-throughput screening, but fail to fully reproduce the structural and cellular complexity of the liver microenvironment. Animal models, particularly those based on mice, rats, and pigs, remain essential for studying the systemic and multicellular aspects of hepatic IRI. Nevertheless, species-specific physiological differences, ethical concerns, high costs, and limited translational predictability represent significant limitations. In this context, three-dimensional liver models have emerged as promising alternatives capable of bridging the gap between in vitro systems and animal experimentation. By more accurately recapitulating tissue architecture, cell–cell interactions, and functional heterogeneity, 3D platforms offer enhanced physiological relevance and translational potential. We discuss the strengths and limitations of each experimental approach and highlight the role of advanced 3D models as complementary tools that may enable more accurate investigations of hepatic IRI and accelerate the development of effective therapeutic strategies. Full article

Historically regarded as competitive modalities, pancreas and islet transplantation are increasingly recognized as complementary approaches to beta-cell replacement therapy. While whole-organ pancreas transplantation remains the established gold standard, islet transplantation has transitioned into an effective clinical alternative for selected cohorts of patients suffering from type 1 diabetes. This review provides a comprehensive evaluation of the clinical evolution characterizing these therapeutic modalities, tracing the shift from static cold storage (SCS) toward innovative dynamic preservation technologies, and exploring potential markers for predicting clinical outcomes. A focus on immunosuppression in islet transplantation is provided, emphasizing precise, tolerance-inducing strategies and investigating costimulation blockade, regulatory T-cell (Treg)-based therapies, and biomaterial-enabled local immunoprotection, with the aim of facilitating long-term graft survival while mitigating the metabolic and renal toxicities secondary to chronic calcineurin inhibitor exposure. Current evidence related to the transition from conventional SCS to advanced perfusion platforms, namely hypothermic machine perfusion (HMP), oxygenated hypothermic perfusion (HOPE), normothermic ex vivo perfusion (NEVP), and normothermic regional perfusion (NRP) is examined: the literature suggests that dynamic pancreas preservation platforms may improve metabolic recovery and some islet isolation outcomes; however, evidence that HOPE specifically reduces ischemia–reperfusion injury and consistently increases islet yield in the pancreas remains limited. Although normothermic perfusion provides significant utility for real-time viability assessment and graft reconditioning, its widespread clinical implementation remains constrained by technical impediments, notably interstitial edema. Ultimately, preservation efficacy is conceptualized not merely as a discrete preservation option, but as a multidimensional construct integrating biological integrity, graft usability, and recipient clinical outcomes. Full article

Background/Objectives: Ischemic stroke (IS) induces substantial phenotypic remodeling within the neurovascular unit, and pericytes have been implicated in the cellular responses to ischemic injury. However, the molecular characteristics and regulatory mechanisms underlying pericyte phenotypic remodeling after ischemic stroke remain incompletely understood. Methods: In this study, we used PDGFR-β-CreERT2; ZsGreen lineage-tracing mice and a middle cerebral artery occlusion (MCAO) model to characterize the temporal changes in PDGFR-β-lineage cells following ischemic injury. In vitro, human brain vascular pericytes (HBVPs) exposed to oxygen–glucose deprivation/reperfusion (OGD/R) and subsequently maintained in neurobasal medium to examine ischemia-related phenotypic changes. The involvement of KLF2-associated signaling was further investigated using KLF2 knockdown approaches. Results: We observed increased expression of Nestin in PDGFR-β-lineage cells during the early post-ischemic period, followed by the emergence of subsets co-expressing GFAP or DCX during the subacute stage. These findings indicate the acquisition of neuroglial- and neuronal-associated molecular features, rather than providing definitive evidence of lineage conversion or functional differentiation. The expression of these markers declined at later stages, whereas PDGFR-β-lineage cells were also associated with vascular remodeling during the recovery phase. In vitro, OGD/R-treated HBVPs exhibited increased expression of DCX, MAP2, and NeuN. KLF2 knockdown attenuated these molecular changes. Consistently, OGD/R was associated with increased KLF2, phosphorylated ERK1/2, and MAP2 expression, whereas KLF2 knockdown reduced ERK1/2 phosphorylation and MAP2 expression. These findings suggest that KLF2 is associated with ERK1/2 activation and MAP2 expression during ischemia-related phenotypic remodeling of PDGFR-β-lineage cells. Conclusions: Overall, our results identify transient neuroglial- and neuronal-associated molecular changes in pericytes after ischemic injury and provide evidence for an association between KLF2 and ERK1/2–MAP2 signaling in this process, while further studies are required to determine whether these changes represent stable lineage conversion or functional neuronal differentiation. Full article

Background: Early post-transplant albuminuria is associated with adverse graft and cardiovascular outcomes and may reflect ischemia–reperfusion injury-induced damage to the glomerular filtration barrier. However, evidence for safe adjunctive interventions targeting these early pathophysiological processes remains limited. Methods: In this single-center prospective cohort study with historical controls, adult kidney transplant recipients transplanted between January 2020 and September 2022 served as controls, while consecutive recipients transplanted from October 2022 onward received adjunctive silymarin (900 mg/day for 30 days) in addition to standard immunosuppression. The principal renal outcome was UACR assessed during the first 3 months post-transplant. A ≥25% reduction in UACR between Months 1 and 3 was additionally evaluated as an exploratory responder outcome. Secondary outcomes included estimated glomerular filtration rate (eGFR), lipid profile parameters, tacrolimus exposure, and safety. Results: A total of 136 patients (78 silymarin-treated and 58 controls) were included. UACR was consistently lower in the silymarin group at months 1–3. In multivariable analysis, silymarin treatment was independently associated with lower UACR at month 3. In an exploratory responder analysis, a ≥25% reduction in UACR between Months 1 and 3 occurred more frequently in silymarin-treated patients (OR 3.28, 95% CI 1.38–7.79; p = 0.007). eGFR trajectories were similar between groups. No consistent independent effects on lipid parameters were observed after adjustment. Tacrolimus exposure and adverse event rates were comparable between groups. Conclusions: Short-term silymarin exposure initiated early after kidney transplantation was associated with lower UACR during the first three post-transplant months. These findings support a potential targeted effect on early glomerular injury and suggest that silymarin may represent a safe adjunctive strategy to modulate early post-transplant risk. Full article

Endovascular thrombectomy [EVT] has revolutionized acute ischemic stroke care by restoring macrovascular reperfusion in large vessel occlusion; however, a persistent “reperfusion–outcome gap” remains, leaving nearly half of successfully recanalized patients without functional independence. This review aims to bridge this translational gap by establishing a mechanistic and procedural framework for adjunctive pharmacotherapy designed to target the microvascular, thromboinflammatory, and reperfusion-related injuries left unaddressed by purely mechanical models. Synthesis of recent literature reveals that futile recanalization is driven by three distinct anatomical and biological bottlenecks: distal microembolization, microcirculatory no-reflow, and ischemia–reperfusion injury. Furthermore, the inconsistency of clinical trial results reflects a critical precision deficit, including dilution of treatment effects across heterogeneous reperfusion grades, inadequate stroke etiology stratification, delayed pharmacologic intervention relative to evolving microvascular injury, and reliance on functional endpoints that inadequately capture tissue-level reperfusion. To address these limitations, this review outlines a tri-axial clinical decision framework integrating reperfusion status, stroke etiology and hemorrhagic risk, which maps specific patient phenotypes, such as incomplete macrovascular reperfusion or underlying intracranial atherosclerotic disease, to targeted pharmacologic strategies including microcatheter-directed intra-arterial thrombolytics and glycoprotein IIb/IIIa inhibitors. The review further argues that future progress will require imaging-guided identification of residual hypoperfusion, mechanistically enriched patient enrolment, and incorporation of biological and tissue-level reperfusion endpoints alongside conventional functional outcomes. Ultimately, closing the reperfusion–outcome gap will require moving beyond empirical, universal drug administration toward a precision, pharmacologically augmented EVT paradigm that aligns adjunctive therapy with mechanism-specific procedural phenotypes and prioritizes true tissue-level recovery over angiographic success alone. Full article

Although the underlying mechanisms of renal IRI have been extensively studied, the corresponding effective treatments are still lacking. HMGB1, an important nuclear factor that is secreted outside cells when experiencing stress conditions, acts as a DAMP and exerts crucial effects on renal IRI. Many studies have suggested that the effect of HMGB1 on kidney damage is mediated mainly through the interaction of HMGB1 with pattern recognition receptors such as TLR4 and RAGE, which then results in the aggravation of local inflammatory response, increased infiltration of leukocytes, and finally renal tubular damage. Preclinical studies using animal models have demonstrated that inhibition of HMGB1 and downstream signal pathways can attenuate renal injury. This review critically evaluates HMGB1 in renal IRI across redox state, subcellular localization, temporal and cell-specific release, receptor usage, integrated stress pathways, autophagy, and regulated cell death. It also compares direct neutralization, inhibition of release or translocation, epigenetic/RNA-based regulation, and receptor-directed strategies. The evidence is predominantly derived from short-term rodent studies, with one large-animal antibody study and no therapeutic human trials. Accordingly, HMGB1 is best regarded as a biologically compelling but clinically unvalidated target whose therapeutic value will depend on redox- and phase-selective inhibition, kidney-directed delivery, and rigorous pharmacokinetic and safety evaluation. Full article

Background/Objectives: Cerebral ischemia–reperfusion injury (CIRI) poses therapeutic challenges because of oxidative stress, blood–brain barrier disruption, and neuronal apoptosis, limiting current treatments. Paeoniflorin (PF) from Paeonia lactiflora has neuroprotective potential, but its multi-target mechanisms remain unclear. This study investigated the role and mechanisms of PF in CIRI, focusing on neuron–endothelial crosstalk. Methods: Oxygen–glucose deprivation/reoxygenation (OGD/R) models were established using SH-SY5Y (human neuroblastoma) and HCMEC/D3 cells (human cerebral microvascular endothelial). Network pharmacology was used to predict potential PF targets and pathways. RNA sequencing, molecular docking, and molecular dynamics simulation were performed to screen and evaluate PF binding characteristics with key targets, and MTT, flow cytometry, Western blotting, and co-cultures were employed to detect paracrine interactions. Results: Network pharmacology and transcriptomics identified VEGF/PI3K-AKT/mTOR pathway enrichment. Molecular docking confirmed stable PF binding to VEGF-A (−8.4 kcal/mol), AKT (−5.5 kcal/mol), and mTOR (−9.6 kcal/mol). PF (10–80 μM) showed no cytotoxicity and reduced OGD/R injury in a concentration-dependent manner (maximal at 40 μM). PF activated VEGF/PI3K-AKT/mTOR signaling, reducing apoptosis by 57% (SH-SY5Y) and 33% (HCMEC/D3); PI3K inhibitor LY294002 abolished these effects. PF-treated HCMEC/D3-conditioned media enhanced OGD/R neuronal viability, verifying paracrine crosstalk. Conclusions: PF alleviated CIRI by directly protecting neurons and indirectly modulating neuron–endothelial crosstalk through VEGF/PI3K-AKT/mTOR activation, supporting its multi-target therapeutic potential. Full article

Cardiac surgery-associated acute kidney injury (CS-AKI) increases short- and long-term mortality, progression to chronic kidney disease (CKD), and healthcare costs. Its pathogenesis is multifactorial—combining renal hypoperfusion, impaired oxygen delivery, hemodilution, inflammation, ischemia–reperfusion injury, and nephrotoxin exposure—so no single intervention confers universal protection. This narrative review appraises fourteen perioperative prevention strategies, grading each by study design, reproducibility, and concordance with contemporary guidelines. The strongest actionable evidence supports the preservation of renal oxygen delivery during cardiopulmonary bypass through goal-directed perfusion, perioperative amino acid infusion, and biomarker-guided Kidney Disease: Improving Global Outcomes (KDIGO) care bundles. Remote ischemic preconditioning, pulsatile flow, minimally invasive extracorporeal circulation, dexmedetomidine, N-acetylcysteine, levosimendan, hemoadsorption with the oXiris membrane, and natriuretic peptides show variable or subgroup-dependent signals limited by heterogeneous trial design and acute kidney injury (AKI) definitions. Prevention of CS-AKI is, therefore, best conceived as a multimodal, patient-centered process integrating preoperative risk stratification, intraoperative oxygen delivery optimization, patient blood management (PBM), and postoperative nephrotoxin avoidance and surveillance. Full article