Neutrophil extracellular traps in wound healing

Stimuli-responsive hydrogel with spatiotemporal co-delivery of FGF21 and H₂S for synergistic diabetic wound repair

Chronic diabetic wounds pose significant clinical challenges due to persistent inflammation, impaired angiogenesis, and disrupted cellular homeostasis. To address these multifactorial barriers, we engineered an injectable, biodegradable, and biocompatible methylated silk fibroin (SilMA) hydrogel system co-loaded with cobalt sulfide (CoS) and fibroblast growth factor 21 (FGF21), designed for on-demand therapeutic release. In the acidic microenvironment characteristic of the inflammatory phase of diabetic wounds, the hydrogel rapidly releases hydrogen sulfide (H₂S) and Co2+ ions, mitigating inflammation and exerting antibacterial effects. Subsequently, during the proliferative and remodeling phases, sustained release of FGF21 promotes cellular proliferation, angiogenesis, and enzymatic homeostasis, thereby accelerating wound healing. Mechanistic studies reveal that the hydrogel facilitates M2 macrophage polarization and activates the JAK/STAT signaling pathway, leading to upregulation of vascular endothelial growth factor (VEGF). Additionally, it enhances antioxidant enzyme activities (superoxide dismutase, catalase, glutathione) while suppressing pro-oxidant enzymes (NADPH oxidase, lipoxygenase, cyclooxygenase). In vivo studies using a diabetic mouse model demonstrate that this dual-functional hydrogel significantly improves wound closure rates and tissue regeneration. These findings suggest that the SilMA-FGF21/CoS hydrogel represents a promising therapeutic strategy for the management of diabetic wounds.

From molecular mechanisms to clinical translation: Silk fibroin-based biomaterials for next-generation wound healing

Silk fibroin (SF) is a natural polymeric material that has attracted intense research attention in the field of wound healing due to its exceptional mechanical properties, tunable biodegradability, and multifunctional bioactivity. This review systematically summarizes the preparation strategies, functional modifications, and multidimensional application mechanisms of SF and its composite materials in wound healing. The innovative applications of SF in intelligent dressing design, immunometabolic regulation, controlled drug release, stem-cell function modulation, and bioelectrical-activity-mediated microenvironment remodeling is further explored, while analyzing the therapeutic efficacy and cost-effectiveness of SF through clinical translation cases. Distinct from previous reviews, this work not only integrates the latest advances in SF molecular mechanisms and material design but also emphasizes its potential in precision medicine, such as the development of genetically engineered SF for customized immunoregulatory networks. Finally, the article highlights the current challenges in the development of SF materials, including mechanical stability, degradation controllability, and standardization of large-scale production, and envisions future research directions driven by 3D bioprinting and synthetic biology technologies. This review provides a theoretical foundation and technical reference information for the development of efficient, multifunctional, and clinically translatable SF-based materials for application in wound healing.

The role of myeloperoxidase in the pathogenesis of stroke

Stroke is the leading cause of mortality and morbidity worldwide, significantly impacting human welfare and overall health. Myeloperoxidase (MPO), a heme peroxidase secreted by neutrophils, plays a crucial role in the body's defense mechanisms, exhibiting pro-inflammatory and pro-oxidative properties. Additionally, MPO compromises the structural integrity and functional capacity of blood vessels, potentially leading to the formation and dislodgement of atherosclerotic plaques, vascular stenosis, thrombosis, and ultimately contributing to stroke occurrence. Following a stroke, a significant influx of neutrophils infiltrates the cerebral tissue, leading to an excessive release of MPO-derived oxidants and the subsequent promotion of various inflammatory mediators, thereby exacerbating cerebral tissue damage. Numerous studies have consistently demonstrated the pivotal role of MPO in the pathogenesis and progression of stroke, establishing it as a reliable prognostic indicator. Exploring the association between MPO and stroke enhances our understanding of the pathological mechanisms underlying stroke and aids in the development of therapeutic interventions. This review provides a comprehensive analysis of the molecular structure and cellular localization of MPO, elucidating its critical role in mediating vascular injury, the formation of Neutrophil Extracellular Traps (NETs), oxidative stress, neuroinflammation, disruption of the blood-brain barrier (BBB), and neuronal apoptosis during stroke pathogenesis. Additionally, we discuss recent advancements in MPO-targeted drugs and Traditional Chinese Medicine compounds as potential therapeutic strategies for stroke treatment.

Advances in Designer Materials for Chronic Wound Healing

Significance: Nonhealing or chronic wounds represent a significant and growing global health concern, imposing substantial burdens on individuals, health care systems, and economies worldwide. Although the standard-of-care treatment involves the application of wound dressings, most dressing materials are not specifically designed to address the pathological processes underlying chronic wounds. This review highlights recent advances in biomaterial design tailored to chronic wound healing. Recent Advances: Chronic wounds are characterized by persistent inflammation, impaired granulation tissue formation, and delayed re-epithelialization. Newly developed designer materials aim to manage reactive oxygen species and extracellular matrix degradation to suppress inflammation while promoting vascularization, cell proliferation, and epithelial migration to accelerate tissue repair. Critical Issues: Designing optimal materials for chronic wounds remains challenging due to the diverse etiology and a multitude of pathological mechanisms underlying chronic wound healing. While designer materials can target specific aberrations, designing a materials approach that restores all aberrant wound-healing processes remains the Holy Grail. Addressing these issues requires a deep understanding of how cells interact with the materials and the complex etiology of chronic wounds. Future Directions: New material approaches that target wound mechanics and senescence to improve chronic wound closure are under development. Layered materials combining the best properties of the approaches discussed in this review will pave the way for designer materials optimized for chronic wound healing.

Lipopolysaccharide-induced DNA damage response activates DNA-PKcs to drive actin cytoskeleton disruption and cardiac microvascular dysfunction in endotoxemia

Rationale: Sepsis-induced cardiomyopathy is characterized by microvascular injury, which is linked to lipopolysaccharide (LPS)-induced DNA damage response (DDR). This study investigates the role of DNA-PKcs, a key enzyme in the DDR pathway, in driving actin disruption and microvascular dysfunction following LPS exposure. Methods: We analyzed diverse transcriptomic datasets from septic human and murine models using bioinformatics tools to assess DDR pathway activation, correlations, and prognosis. In vivo, LPS-challenged mice were treated with inhibitors of DNA-PKcs or mitochondrial fission, and we evaluated cardiac function, microvascular integrity, mitochondrial status, and actin polymerization. Results: Bioinformatic analyses consistently revealed significant activation of the DDR pathway and upregulation of key genes across diverse septic models. Notably, elevated DDR pathway activity was significantly correlated with poor 28-day survival in human sepsis patients. Single-cell analysis localized this DDR gene upregulation predominantly to cardiac endothelial cells (ECs), fibroblasts, and macrophages during sepsis. Within septic capillary ECs, DDR pathway activity scores strongly correlated spatially and functionally with heightened mitochondrial fission and cytoskeletal remodeling pathway activities. In vivo experiments confirmed that LPS induced severe systolic and diastolic dysfunction, microvascular damage, and mitochondrial fragmentation, as well as significant actin depolymerization. Inhibition of DNA-PKcs with NU7441 markedly attenuated all these LPS-induced pathologies, improving cardiac function, preserving microvascular structure, preventing mitochondrial fragmentation, and normalizing related gene expression and actin cytoskeleton stability. Additionally, inhibiting mitochondrial fission with Mdivi-1 significantly ameliorated LPS-induced cardiac dysfunction and microvascular injury. Conclusions: Our findings suggest that LPS triggers a DNA-PKcs-dependent DDR that promotes mitochondrial fragmentation and actin disruption, particularly in cardiac ECs, contributing to sepsis-induced cardiomyopathy. Targeting DNA-PKcs or mitochondrial fission may hold therapeutic potential for the treatment of sepsis-induced cardiomyopathy.

Nuclear damage-induced DNA damage response coupled with IFI16-driven ECM remodeling underlies dilated cardiomyopathy

Rationale: Dilated cardiomyopathy (DCM) is a severe cardiac condition characterized by ventricular dilation and systolic dysfunction, often leading to heart failure. While the DNA damage response (DDR) pathway is increasingly implicated in DCM pathogenesis, the precise mechanisms linking DDR activation to specific pathological features like adverse extracellular matrix (ECM) remodeling and fibrosis remain poorly understood. Interferon-inducible protein 16 (IFI16), a known DNA sensor involved in DDR and inflammatory signaling, emerges as a potential mediator in this process. This study aimed to investigate the role of the DDR-IFI16 axis in DCM, specifically exploring its connection to ECM dysregulation and cardiac dysfunction, and to evaluate its potential as a therapeutic target. Methods: W This study integrated bioinformatics analyses of human cardiac transcriptomic datasets with experimental validation in a doxorubicin-induced murine DCM model. Cardiac function was assessed by echocardiography. Key molecular pathways were investigated using qPCR, ELISA, and enrichment analyses. Mechanistic roles were tested via pharmacological DDR inhibition in vivo and targeted IFI16 siRNA knockdown in vitro, followed by analysis of fibrosis, cell viability, and cytotoxicity markers. Results: Bioinformatic analyses consistently revealed activation of DDR and cytosolic DNA sensing pathways across human iPSC-CM models and ex vivo DCM heart tissue. WGCNA identified a key gene module strongly associated with DCM, co-enriched for DDR, DNA replication, and ECM/TGF-β signaling pathways. Single-cell RNA-seq analysis confirmed significant IFI16 upregulation in human DCM samples. High IFI16 expression strongly correlated with pathways governing 'Extracellular matrix organization' and key fibrotic genes. Experimental validation in the doxorubicin mouse model confirmed DDR activation. Crucially, in vivo treatment with the DDR inhibitor NU7441 significantly attenuated IFI16 upregulation, ameliorated cardiac dysfunction, and decreased cardiac fibrosis markers. Complementarily, in vitro knockdown of IFI16 significantly reduced pro-fibrotic markers, increased cell viability, and decreased cell injury. Conclusions: Our findings delineate a novel pathogenic axis in DCM where nuclear stress-induced DDR activation drives the upregulation of the DNA sensor IFI16. IFI16 acts as a critical mediator linking DDR signaling to pathological ECM remodeling and fibrosis. Pharmacological inhibition of the upstream DDR pathway effectively mitigates IFI16 induction, attenuates cardiac fibrosis, and improves cardiac function. This study identifies the DDR-IFI16-ECM remodeling axis as a crucial contributor to DCM pathogenesis and highlights its potential as a therapeutic target for mitigating adverse cardiac remodeling and dysfunction.

Dynamic changes in peripheral inflammation as a risk factor for perioperative sleep disturbances in elderly patients undergoing laparoscopic hepatobiliary surgery

Background

Elderly surgical patients are at high risk of perioperative sleep disturbances (PSD), and the underlying pathogenic mechanisms remain unclear. The relationship between peripheral inflammatory status and PSD pathogenesis currently lacks substantial clinical evidence.

Objective

This study aims to evaluate the association between peripheral inflammation indicators and PSD in elderly patients undergoing laparoscopic hepatobiliary surgery, and to analyze the dynamic changes in peripheral inflammation in PSD patients throughout the perioperative period.

Method and materials

Using retrospective data, this study compares peripheral inflammatory markers (NLR, MLR, PLR, SII, IL-6, and IL-10) in patients with PSD vs. those with normal sleep patterns before and after surgery. Receiver operating characteristic (ROC) curves were employed to evaluate the discriminative power of these indicators for PSD. Logistic regression models were employed to assess risk associations between inflammatory markers and PSD. Dynamic changes in peripheral inflammation were compared before surgery, on the day the surgery ended, and 1 day post-surgery between patients with PSD and those with normal sleep, exploring potential correlations with PSD pathogenesis.

Result

The study ultimately included clinical data from 156 patients. Findings indicated that elevated NLR and SII levels before and after surgery, alongside decreased plasma IL-10 levels post-surgery, are associated with a higher incidence of PSD. Peripheral inflammatory markers on the day of surgery were not significantly predictive of post-PSD. Multivariable logistic regression analyses identified NLR, SII, IL-6, and IL-10 as independent predictors of pre-PSD, while NLR, SII, and IL-10 remained independently associated with post-PSD.

Conclusion

Dynamic changes in peripheral inflammation during the perioperative period are associated with PSD in elderly patients undergoing laparoscopic hepatobiliary surgery. These findings may support the early identification and screening of high-risk PSD patients, providing new insights into the underlying mechanisms of PSD pathogenesis.

Neutrophil extracellular traps (NETs) are increased in rheumatoid arthritis-associated interstitial lung disease

BACKGROUND

Neutrophil extracellular trap (NET) formation has been implicated as a pathogenic mechanism in both rheumatoid arthritis (RA) and interstitial lung disease (ILD). However, the role of NETs in RA-associated ILD (RA-ILD) and the mechanisms driving NET formation remain unclear. This study aimed to assess the involvement of NETs in RA-ILD and elucidate the underlying mechanisms.

METHODS

Single-cell sequencing was used to identify changes in the quantity and function of neutrophils in the lung tissue of a zymosan A (ZYM)-induced interstitial pneumonia arthritis model. Additionally, nuclear receptor 4A3 (NR4A3) interference was performed in HL-60 cells to assess its impact on NET formation and the transformation of MRC-5 cells into myofibroblasts. The clinical relevance of plasma myeloperoxidase-DNA (MPO-DNA), citrullinated histone 3 (Cit-H3), and cell-free DNA was evaluated in RA-ILD patients with different imaging types via a commercial enzyme-linked immunosorbent assay (ELISA).

RESULTS

In the ZYM-treated SKG mouse model, which recapitulates key features of RA-ILD, an increased population of neutrophils in the lung tissue was primarily responsible for NET formation. Mechanistically, we found that interference with NR4A3 expression enhanced NET formation in HL-60 cells, which in turn promoted the differentiation of MRC-5 cells into myofibroblasts. Clinically, plasma MPO-DNA levels are elevated in patients with RA-nonspecific interstitial pneumonia (RA-NSIP), whereas Cit-H3 levels are elevated in RA-usual interstitial pneumonia (RA-UIP) patients compared with healthy subjects. ROC curve analysis further revealed that the combination of plasma MPO-DNA, rheumatoid factor (RF), and anti-citrullinated protein (anti-CCP) and the combination of Cit-H3, RF, and anti-CCP were superior diagnostic panels for NSIP and UIP in RA-ILD patients, respectively. Moreover, compared with those from healthy controls, neutrophils from patients with RA-UIP and RA-NSIP demonstrated a significantly increased ability to form NETs and induce the differentiation of MRC-5 cells into myofibroblasts. Specifically, RA-UIP patients exhibited a greater capacity for NET formation and the differentiation of MRC-5 cells into myofibroblasts than did RA-NSIP patients.

CONCLUSIONS

These findings suggest that targeting NETs may be a novel therapeutic approach for treating ILD in RA patients.