Abstract Ischemia–reperfusion injury (IRI) is a major cause of tissue damage in patients with myocardial infarction, stroke, acute kidney injury, and intestinal Ischemia. Restoring blood flow is necessary for tissue survival, but injury is often worsened by reperfusion through too much oxidative stress, inflammation without infection, and controlled cell death. As a result, current therapies are limited in their effectiveness. Extracellular vesicles (EVs) are small vesicles with a lipid bilayer, and they are released by most cell types. These EVs have become a possible cell-free treatment for IRI. Their high biocompatibility, intrinsic immunomodulatory properties, and organ-targeting capability enable the efficient delivery of protective and regenerative biomolecules across physiological barriers. This review sums up new progress in treatments that use EVs for IRI in several organ systems, and it also pays attention to three related parts. The first part is about the main ways EVs may work in treatment, and these ways include effects that reduce damage from oxidation, lower inflammation, and help tissues repair. This review discusses these points as well. Second, this review also describes that EVs derived from stem cells, endothelial cells, and immune cells show functional heterogeneity. In other words, the functions of these EVs are not the same, and this point is also discussed here. Third, some recent engineering methods are also stressed,such as surface modification, cargo loading, and biomaterial-assisted delivery, are highlighted. The review also pays attention to these methods.This review does more than sum up the progress that already exists; it also discusses an important gap, that is, how to make more reasonable design plans that link EVs with IRI therapy; in addition, this review addresses some key problems in turning these findings into practical use, and these problems include producing EVs in large amounts, controlling their quality, and checking whether they are safe in the body.
Abstract Background Severe trauma is commonly accompanied by secondary infection and multiple organ dysfunction, wherein sepsis and SIMD constitute predominant determinants of fatal outcomes. Despite this, the mechanistic connection between systemic hemolysis and cardiac immune remodeling has yet to be defined. Accordingly, this study was designed to determine whether CFH drives septic cardiac injury and to elucidate the cellular and molecular basis underlying this process. Methods Clinical samples from patients with sepsis, cecal ligation and puncture (CLP) mouse models, single-cell RNA sequencing, metabolomic profiling, high-resolution live-cell imaging, and genetic manipulation were integrated to characterize CFH-mediated cardiac remodeling. Intercellular mitochondrial transfer was dynamically tracked using fluorescence imaging and super-resolution microscopy. A hemoglobin-targeting nanoparticle (HbAb-NP) was developed to evaluate the therapeutic potential of CFH scavenging. Results Circulating CFH was markedly elevated in septic patients and CLP mice and was associated with myocardial hemoglobin deposition, endothelial barrier disruption, cardiac dysfunction, and poor survival. CFH exposure was associated with an increased relative proportion of a metabolically reprogrammed CD163+ macrophage subset through activation of the glycolysis–NF-κB1 signaling axis. These macrophages exhibited mitochondrial dysfunction and transferred damaged mitochondria to endothelial cells via tunneling nanotubes (TNTs), resulting in oxidative stress, impaired mitochondrial respiration, endothelial barrier disruption, and reduced angiogenic capacity. Mechanistically, Drp1 facilitated TNT formation by activating the Cdc42/Rac1–cofilin/profilin pathway to drive actin cytoskeletal remodeling. Therapeutically, HbAb-NP efficiently scavenged circulating CFH, suppressed CD163+ macrophage activation, alleviated endothelial injury, improved cardiac function, and prolonged survival in septic mice. Conclusions This study identifies circulating CFH as a previously unrecognized upstream regulator linking systemic hemolysis to cardiac immune microenvironment remodeling during sepsis. CFH-induced CD163+ macrophage reprogramming and Drp1-dependent pathological mitochondrial transfer establish a macrophage–mitochondria–endothelial injury axis that drives SIMD. Targeting circulating CFH represents a promising therapeutic strategy for sepsis-associated cardiac dysfunction.
Abstract Background Wound healing is an environmentally adaptive process. It requires a tightly coordinated transition from an inflammatory to a proliferative state, which occurs in response to oxidative and inflammatory stress. Molecular hydrogen (H2) is a widely recognized medical gas, and it alleviates oxidative stress and selectively eliminates highly cytotoxic reactive oxygen species. However, it remains unclear whether redox-active gases such as H2 can actively orchestrate tissue state transitions, rather than merely mitigating oxidative damage. Methods Bulk RNA sequencing, single-cell RNA sequencing, and spatial transcriptomic analyses were integrated to investigate the cellular and molecular mechanisms underlying H2-mediated wound healing. Functional studies were performed in hydrogen-mediated mouse skin injury models and in self-assembled skin organoid models. Immunofluorescence staining, Masson’s trichrome staining, and qRT-PCR were used to validate key signaling pathways and assess tissue regeneration, angiogenesis, and wound healing outcomes. Results H2 significantly accelerated wound healing, especially during the proliferative phase, where it acted as a critical regulator of the inflammatory-to-proliferative transition. Multi-omics analyses identified a hydrogen-associated macrophage program and revealed a CXCL2-ACKR1 signaling axis mediating macrophage-endothelial communication. Functional validation confirmed that activation of this axis promoted endothelial migration, angiogenesis, and granulation tissue formation. As a result, the transition from inflammation to proliferation was facilitated, and wound closure was accelerated. Conclusions H2 spatiotemporally coordinates adaptive wound healing by regulating a macrophage-endothelial CXCL2-ACKR1 signaling axis that drives the inflammatory-to-proliferative transition. These findings provide mechanistic insight into how H2 spatiotemporally coordinates adaptive wound healing and highlight the potential of hydrogen-mediated redox modulation as a mechanism for regulating tissue repair.
Abstract Background Nitrogen mustard (HN2) is a bifunctional alkylating vesicant that produces blistering and ulcerative skin lesions, yet the molecular events responsible for this tissue damage remain incompletely defined. This study aimed to identify the direct protein targets of HN2 in human skin and elucidate how target alkylation affects mitochondrial function and thereby causes skin injury. Methods An activity based probe, HNP-1, was designed for fluorescence imaging and chemical proteomic target mapping. Biochemical assays and site-directed mutagenesis were employed to confirm HN2 binding to electron-transferring flavoprotein dehydrogenase (ETFDH) and to identify the modified residue. Additionally, transcriptomic profiling and a murine cutaneous injury model were used to characterize downstream events and evaluate the effects of vitamin B2 (VB2). Results HNP-1 enabled direct visualization of HN2-derived labeling in skin cells and tissues and showed that the signal was predominantly extranuclear. Unbiased proteomic analysis then identified ETFDH as a high-affinity mitochondrial target. HN2 alkylated ETFDH at His112, impairing its interaction with ubiquinol–cytochrome c reductase core protein 2 (UQCRC2) and triggering mitochondrial oxidative stress, voltage-dependent anion channel 1 (VDAC1) oligomerization, and mitochondrial DNA (mtDNA) release. These events promoted cGAS-STING signaling and pyroptosis, whereas the H112A substitution blunted the response. Intraperitoneal VB2 administration restored the epidermal flavin adenine dinucleotide (FAD) level and attenuated HN2-induced skin injury in mice. Conclusions These findings link ETFDH alkylation to pyroptotic signaling in acute HN2 skin injury and show that VB2 mitigates skin damage in severely exposed mice.
Abstract In recent years, the role of mechanosensation in lymphatic system development, functional homeostasis, and disease progression has received increasing attention. As key mechanosensitive receptors in lymphatic endothelial cells, Piezo1/2 ion channels respond to biomechanical stimuli such as fluid shear stress and interstitial pressure, thereby regulating calcium influx and downstream signaling pathways. These channels play pivotal roles in physiological processes, including lymphatic network formation, valve development, and the maintenance of meningeal lymphatic function. This review systematically describes the structural features and dynamic mechanisms of Piezo1/2 channels, with a particular focus on their biological functions within the lymphatic system. Piezo1 integrates multiple signaling pathways, including the Orai1/Notch, ANGPT/TIE/FOXO1, and EPHB4/RASA1 signaling pathways, to regulate lymphatic sprouting, valve morphogenesis, and meningeal lymphatic development. Dysregulation of Piezo1 function has been demonstrated to be closely associated with congenital lymphoedema, tumor lymphatic metastasis, and neurological disorders such as hydrocephalus and craniosynostosis. In addition, the potential role of Piezo2 in the sensory impairments associated with lymphoedema warrants attention. With respect to therapeutic strategies, this review comprehensively summarizes approaches targeting Piezo1/2, including the development of small-molecule agonists/inhibitors, gene-editing technologies, physical modulation methods, and advanced drug delivery systems, as well as their research progress and clinical prospects. Despite persistent challenges such as insufficient tissue specificity and limited spatiotemporal precision, the integration of multiscale biomechanical models, organoid platforms, and multidisciplinary research strategies holds promise for translational breakthroughs in Piezo1/2 ion channel research, providing a new paradigm for precision therapy of lymphatic system-related diseases.
