A ROS-Responsive Lipid Nanoparticles Release Multifunctional Hydrogel Based on Microenvironment Regulation Promotes Infected Diabetic Wound Healing.

The continuous imbalance of the diabetic wound microenvironment is an important cause of chronic nonhealing, which manifests as a vicious cycle between excessive accumulation of reactive oxygen species (ROS) and abnormal healing. Regulating the microenvironment by suppressing wound inflammation, oxidative stress, and bacterial infection is a key challenge in treating diabetic wounds. In this study, ROS-responsive hydrogels are developed composed of silk fibroin methacrylated (SFMA), modified collagen type III (rCol3MA), and lipid nanoparticles (LNPs). The newly designed hydrogel system demonstrated stable physicochemical properties and excellent biocompatibility. Moreover, the release of antimicrobial peptide (AMP) and puerarin (PUE) demonstrated remarkable efficacy in eradicating bacteria, regulating inflammatory responses, and modulating vascular functions. This multifunctional hydrogel is a simple and efficient approach for the treatment of chronic diabetic infected wounds and holds tremendous potential for future clinical applications.

Impact of the gut microbiome on skin fibrosis: a Mendelian randomization study.

Objective: Skin fibrosis is a lesion in the dermis causing to itching, pain, and psychological stress. The gut microbiome plays as an essential role in skin diseases developments. We conducted a Mendelian randomization study to determine the causal association between the gut microbiome and skin fibrosis. Methods: We retrieved valid instrumental variables from the genome-wide association study (GWAS) files of the gut microbiome (n = 18,340) conducted by the MiBioGen consortium. Skin fibrosis-associated data were downloaded from the GWAS Catalog. Subsequently, a two-sample Mendelian randomization (MR) analysis was performed to determine whether the gut microbiome was related to skin fibrosis. A reverse MR analysis was also performed on the bacterial traits which were causally associated with skin fibrosis in the forward MR analysis. In addition, we performed an MR-Pleiotropy Residual Sum and Outlier analysis to remove outliers and a sensitivity analysis to verify our results. Results: According to the inverse variance-weighted estimation, we identified that ten bacterial traits (Class Actinobacteria, Class Bacteroidia, family Bifidobacteriaceae, family Rikenellaceae, genus Lachnospiraceae (UCG004 group), genus Ruminococcaceae (UCG013 group), order Bacteroidales, order Bifidobacteriales, genus Peptococcus and genus Victivallis) were negatively correlated with skin fibrosis while five bacterial traits (genus Olsenella, genus Oscillospira, genus Turicibacter, genus Lachnospiraceae (NK4A136group), and genus Sellimonas) were positively correlated. No results were obtained from reverse MR analysis. No significant heterogeneity or horizontal pleiotropy was observed in MR analysis. Objective conclusion: There is a causal association between the gut microbiome and skin fibrosis, indicating the existence of a gut-skin axis. This provides a new breakthrough point for mechanistic and clinical studies of skin fibrosis.

The naringin/carboxymethyl chitosan/sodium hyaluronate/silk fibroin scaffold facilitates the healing of diabetic wounds by restoring the ROS-related dysfunction of vascularization and macrophage polarization.

Chronic diabetic wounds remain a globally recognized clinical challenge, which occurs mainly due to the disturbances of wound microenvironmental induced by high concentrations of reactive oxygen species (ROS). Impairments in angiogenesis and inflammation in the wound microenvironment ultimately impede the normal healing process. Therefore, targeting macrophage and vascular endothelial cell dysfunction is a promising therapeutic strategy. In our study, we fabricated artificial composite scaffolds composed of naringin/carboxymethyl chitosan/sodium hyaluronate/silk fibroin (NG/CMCS/HA/SF) to promote wound healing. The NG/CMCS/HA/SF scaffold demonstrated favorable anti-inflammatory, anti-oxidative, and pro-angiogenic properties in both in vitro and in vivo experiments, effectively promoting the healing of diabetic wounds. The positive therapeutic effects observed indicate that the composite scaffolds have great potential in clinical wound healing applications.

S-Nitrosylation-mediated coupling of DJ-1 with PTEN induces PI3K/AKT/mTOR pathway-dependent keloid formation.

Background: Keloids are aberrant dermal wound healing characterized by invasive growth, extracellular matrix deposition, cytokine overexpression and easy recurrence. Many factors have been implicated as pathological causes of keloids, particularly hyperactive inflammation, tension alignment and genetic predisposition. S-Nitrosylation (SNO), a unique form of protein modification, is associated with the local inflammatory response but its function in excessive fibrosis and keloid formation remains unknown. We aimed to discover the association between protein SNO and keloid formation. Methods: Normal and keloid fibroblasts were isolated from collected normal skin and keloid tissues. The obtained fibroblasts were cultured in DMEM supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. The effects of DJ-1 on cell proliferation, apoptosis, migration and invasion, and on the expression of proteins were assayed. TurboID-based proximity labelling and liquid chromatography-mass spectrometry were conducted to explore the potential targets of DJ-1. Biotin-switch assays and transnitrosylation reactions were used to detect protein SNO. Quantitative data were compared by two-tailed Student's t test. Results: We found that DJ-1 served as an essential positive modulator to facilitate keloid cell proliferation, migration and invasion. A higher S-nitrosylated DJ-1 (SNO-DJ-1) level was observed in keloids, and the effect of DJ-1 on keloids was dependent on SNO of the Cys106 residue of the DJ-1 protein. SNO-DJ-1 was found to increase the level of phosphatase and tensin homolog (PTEN) S-nitrosylated at its Cys136 residue via transnitrosylation in keloids, thus diminishing the phosphatase activity of PTEN and activating the PI3K/AKT/mTOR pathway. Furthermore, Cys106-mutant DJ-1 is refractory to SNO and abrogates DJ-1-PTEN coupling and the SNO of the PTEN protein, thus repressing the PI3K/AKT/mTOR pathway and alleviating keloid formation. Importantly, the biological effect of DJ-1 in keloids is dependent on the SNO-DJ-1/SNO-PTEN/PI3K/AKT/mTOR axis. Conclusions: For the first time, this study demonstrated the effect of transnitrosylation from DJ-1 to PTEN on promoting keloid formation via the PI3K/AKT/mTOR signaling pathway, suggesting that SNO of DJ-1 may be a novel therapeutic target for keloid treatment.

Epidermal Stem Cell Derived Exosomes Alleviate Excessive Autophagy Induced Endothelial Cell Apoptosis by Delivering miR200b-3p to Diabetic Wounds.

The dysfunction of endothelial cells caused by hyperglycemia is observed as a decrease in neovascularization in diabetic wound healing. Studies have found that epidermal stem cells (EpiSCs) can promote the angiogenesis of full-thickness wounds. To further explain the therapeutic effect of EpiSCs, EpiSC-derived exosomes (EpiSC-EXOs) are considered the main substance contributing to stem cell effectivity. In our study, EpiSCs and EpiSC-EXOs were supplied to the dorsal wounds of db/db mice. Results showed that EpiSCs could colonize in the wound area and both EpiSCs and EpiSC-EXOs could accelerate diabetic wound healing by promoting angiogenesis. In vitro, persistent high glucose led to the malfunction and apoptosis of endothelial cells. The apoptosis induced by high glucose is due to excessive autophagy and was alleviated by EpiSC-EXOs. RNA sequencing of EpiSC-EXOs showed that miR200b-3p was enriched in EpiSC-EXOs and alleviated the apoptosis of endothelial cells. Synapse defective rho GTPase homolog 1 was identified the target of miR200b-3p and affected the phosphorylation of ERK to regulate intracellular autophagy and apoptosis. Furthermore, animal experiments validated the angiogenic effect of miR200b-3p. Collectively, our results verified the effect of EpiSC-EXOs on apoptosis caused by hyperglycemia in endothelial cells through the miR200b-3p/synapse defective rho GTPase homolog 1 /RAS/ERK/autophagy pathway, providing a theoretical basis for EpiSC in treating diabetic wounds.

Targeting phenylpyruvate restrains excessive NLRP3 inflammasome activation and pathological inflammation in diabetic wound healing.

Moderate inflammation is essential for standard wound healing. In pathological conditions, such as diabetes, protracted and refractory wounds are associated with excessive inflammation, manifested by persistent proinflammatory macrophage states. However, the mechanisms are still unclear. Herein, we perform a metabolomic profile and find a significant phenylpyruvate accumulation in diabetic foot ulcers. Increased phenylpyruvate impairs wound healing and augments inflammatory responses, whereas reducing phenylpyruvate via dietary phenylalanine restriction relieves uncontrolled inflammation and benefits diabetic wounds. Mechanistically, phenylpyruvate is ingested into macrophages in a scavenger receptor CD36-dependent manner, binds to PPT1, and inhibits depalmitoylase activity, thus increasing palmitoylation of the NLRP3 protein. Increased NLRP3 palmitoylation is found to enhance NLRP3 protein stability, decrease lysosome degradation, and promote NLRP3 inflammasome activation and the release of inflammatory factors, such as interleukin (IL)-1ß, finally triggering the proinflammatory macrophage phenotype. Our study suggests a potential strategy of targeting phenylpyruvate to prevent excessive inflammation in diabetic wounds.

Single-stage transplantation combined with epidermal stem cells promotes the survival of tissue-engineered skin by inducing early angiogenesis.

BACKGROUND: The composite transplantation of a split-thickness skin graft (STSG) combined with an acellular dermal matrix (ADM) is a promising repair method for full-thickness skin defects. Due to delayed vascularization of the ADM, no currently available engineered skin tissue is able to permanently cover full-thickness skin defects via a single-stage procedure. Epidermal stem cells (EpSCs) have been found to promote angiogenesis in the wound bed. Whether EpSCs can induce early angiogenesis of dermal substitutes and promote the survival of single-stage tissue-engineered skin transplantation needs to be further studied. METHODS: In vitro, rat vascular endothelial cells (RVECs) were treated with the supernatant of EpSCs cultured in ADM and stimulated for 48 h. RVECs were analysed by RNA sequencing and tube formation assays. For the in vivo experiment, 75 rats were randomly divided into five groups: ADM, ADM + EpSCs (AE), STSG, ADM + STSG (AS), and ADM + STSG + EpSCs (ASE) groups. The quality of wound healing was estimated by general observation and H&E and Masson staining. The blood perfusion volume was evaluated using the LDPI system, and the expression of vascular markers was determined by immunohistochemistry (IHC). RESULTS: The active substances secreted by EpSCs cultured in ADM promoted angiogenesis, as shown by tube formation experiments and RNA-seq. EpSCs promoted epithelialization of the ADM and vascularization of the ADM implant. The ASE group showed significantly increased skin graft survival, reduced skin contraction, and an improved cosmetic appearance compared with the AS group and the STSG control group. CONCLUSIONS: In summary, our findings suggest that EpSCs promote the formation of new blood vessels in dermal substitutes and support one-step transplantation of tissue-engineered skin, and thereby provide new ideas for clinical application.

Analysis of miR-203a-3p/SOCS3-mediated induction of M2 macrophage polarization to promote diabetic wound healing based on epidermal stem cell-derived exosomes.

BACKGROUND: The development of therapeutic strategies to improve wound healing in individual diabetic patients remains challenging. Stem cell-derived exosomes represent a promising nanomaterial, and microRNAs (miRNAs) can be isolated from them. It is important to identify the potential therapeutic role of specific miRNAs, given that miRNAs can play a therapeutic role. METHODS: qPCR, flow cytometry, and western blotting were used to verify the effect of epidermal stem cell-derived exosomes (EpiSC-EXOs) on M2 macrophage polarization and SOCS3 expression. By screening key miRNAs targeting SOCS3 in EpiSC-EXOs by high-throughput sequencing, we verified the mechanism in vitro. Finally, an animal model was used to verify the effect of promoting healing. RESULTS: The use of EpiSC-EXOs reduced SOCS3 expression and promoted M2 macrophage polarization. The abundant miR-203a-3p present in the EpiSC-EXOs specifically bound to SOCS3 and activated the JAK2/STAT3 signaling pathway to induce M2 macrophage polarization. Treatment of the db/db mouse wound model with miR-203a-3p agomir exerted a pro-healing effect. CONCLUSIONS: Our results demonstrated that the abundant miR-203a-3p present in EpiSC-EXOs can promote M2 macrophage polarization by downregulating SOCS3 and suggested that diabetic wounds can obtain better healing effects through this mechanism.

Bioinformatic Analysis Reveals Hub Immune-Related Genes of Diabetic Foot Ulcers.

Diabetic foot ulcer (DFU) is a complex and devastating complication of diabetes mellitus that are usually stagnant in the inflammatory phase. However, oral wound healing, which is characterized by a rapid and scarless healing process, is regarded an ideal model of wound healing. Thus, we performed a comprehensive bioinformatics analysis of the previously published data regarding oral ulcers and DFUs and found that compared to oral wound healing, the activated pathways of DFUs were enriched in cellular metabolism-related pathways but lacked the activation of inflammatory and immune-related pathways. We also found that CXCL11, DDX60, IFI44, and IFI44L were remarkable nodes since they had the most connections with other members of the module. Meanwhile, CXCL10, IRF7, and DDX58 together formed a closed-loop relationship and occupied central positions in the entire network. The real-time polymerase chain reaction and western blot was applied to validate the gene expression of the hub immune-related genes in the DFU tissues, it was found that CXCL11, IFI44, IFI44L, CXCL10 and IRF7 have a significant difference compared with normal wound tissues. Our research reveals some novel potential immune-related biomarkers and provides new insights into the molecular basis of this debilitating disease.

Clinical Studies on Platelet-Rich Plasma Therapy for Chronic Cutaneous Ulcers: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Significance: Platelet-rich plasma (PRP) may be a potential drug for treatment of chronic refractory ulcers, which increase the risk of systemic infection and local canceration. However, the efficacy and safety of clinical application of PRP are still controversial. Thus, this study was aimed to assess the efficacy and safety of PRP in patients with chronic ulcers. Recent Advances: For this meta-analysis, Cochrane's Library, MEDLINE, EMBASE, PubMed, Web of Science, and CINAHL (Cumulate Index to Nursing and Allied Health Literature) databases were searched. Results were pooled using a random-effects model. The primary outcome was the proportion of completely healed chronic ulcers. Critical Issues: Seventeen randomized controlled trials were included. Compared with the control group, PRP significantly increased the fraction of healed ulcers (pooled risk ratio [RR] = 1.50; 95% confidence interval [CI] = 1.20 to 1.87; I2 = 47.8%). In autologous PRP (APRP) and homologous PRP (HPRP) subgroups, there were statistical differences between the control group versus treatment subgroup (pooled RR = 1.30, 95% CI = 1.10 to 1.54, I2 = 25.7%; pooled RR = 3.53, 95% CI = 1.94 to 6.43, I2 = 0.0%, respectively). In terms of percent of chronic ulcers area healed, there was a statistically significant difference between the PRP-treated group versus the control group (standard mean difference [SMD] = 1.37, 95% CI = 0.91 to 1.82, I2 = 22.1%). As for PRP safety, there existed a statistically significant difference between the APRP subgroup and the HPRP subgroup, respectively (pooled RR = 0.58; 95% CI = 0.35 to 0.98; I2 = 0.0%) and (pooled RR = 4.12; 95% CI = 1.55 to 10.96; I2 = 6.8%). Future Directions: Our findings shows that PRP may be a beneficial treatment of chronic skin ulcers and that APRP may be much safer than HPRP.

Upregulated Histone Deacetylase 6 Associates with Malignant Progression of Melanoma and Predicts the Prognosis of Patients.

BACKGROUND: Melanoma is the most malignant tumor among skin tumors, and its morbidity and mortality are increasing year by year. Although melanoma biology has been increasingly studied, no prognostic biomarkers have yet been incorporated into clinical protocols. Histone deacetylase 6 (HDAC6) has been shown to act as a prognostic biomarker in several cancers. Here, we aimed to investigate the predictive value of HDAC6 for the prognosis of cutaneous melanoma patients. METHODS: Eighty cutaneous melanoma patients were enrolled in this study. The protein and mRNA expression levels of HDAC6 were detected, and the clinical features and survival time of cutaneous melanoma patients with HDAC6 expression were analyzed. RESULTS: The results suggested that high HDAC6 expression was significantly associated with unfavorable clinicopathological features. High HDAC6 expression was related to melanoma metastasis and was also associated with a reduced survival time in melanoma patients, and this association remained significant in multivariate analysis adjusted for all other factors. CONCLUSION: These findings validate the utility of HDAC6 expression as an independent biomarker for the prognostication of patients with cutaneous melanoma.