Fibroblasts: Immunomodulatory factors in refractory diabetic wound healing

Increased ROS and Persistent Pro-Inflammatory Responses in a Diabetic Wound Healing Model (db/db): Implications for Delayed Wound Healing

Diabetes and its complications, including impaired wound healing, present a critical clinical challenge and burden for the U.S. healthcare system, with costs of over USD 13 billion annually. Hyperglycemia and chronic inflammation in diabetic wounds increase reactive oxygen species (ROS) production, inducing oxidative stress and perpetuating inflammation, which delays healing. This study investigates inflammation, oxidative stress, and the roles of cellular populations in a diabetic wound healing mouse model (db/db). Given that diabetes leads to persistent inflammation and impaired fibroblast function, we also examined how diabetes influences superoxide production in dermal fibroblasts. Blood, dermal fibroblasts, and wound tissue were collected from 12-week-old female diabetic (Db) and heterozygous (Hz) mice. Electron paramagnetic resonance (EPR) spectroscopy revealed higher superoxide levels in diabetic blood, dermal fibroblasts, and wounds compared to controls. In diabetic wounds, immunohistochemistry and flow cytometry showed increased leukocyte infiltration and reduced macrophage presence, with a higher proportion of pro-inflammatory Ly6Chi macrophages. These results suggest that elevated superoxide production and persistent inflammation contribute to impaired fibroblast function and delayed wound healing in diabetes. By identifying the contributions of ROS and Ly6Chi macrophages to oxidative stress and chronic inflammation, this study offers insights into therapeutic strategies. These findings highlight the importance of addressing systemic oxidative stress alongside localized inflammation to improve wound healing outcomes in diabetic patients and advance diabetic wound care strategies.

Fibromodulin-overexpressing fibroblast cells increase wound contraction, improve scar quality and enhance angiogenesis: an in-vivo study

INTRODUCTION

Fibromodulin, a small leucine rich proteoglycan has been suggested to have prominent role in wound healing. On the other hand, fibroblast cells, due to their ability to secrete growth factors and control inflammation in the wound area, have been proposed as effective approaches in cell therapy for wounds. In the current study we attempted to improve treatment results using a combination of fibroblast and fibromodulin features.

METHOD

Fibroblast cells were isolated from the skin and transfected with a vector carrying the fibromodulin gene. Following the assessment of fibromodulin protein production, the effect of transfected fibroblast cells was studied in an animal wound model.

RESULTS

Flow cytometry analysis showed high expression of the CD90 marker (97.2%) and very low expression of the CD34 marker (0.47%). Additionally, enzyme-linked immunosorbent assay (ELISA) findings confirmed high expression of the fibromodulin gene in the transfected fibroblast cells. In vivo studies demonstrated that the animals treated with fibroblast cells transfected with fibromodulin (V + G+) exhibited significantly improved wound contraction on day 7 (i.e., contraction percentage: 21.79 ± 9.96%, compared with 7.23 ± 2.30% in the PBS-treated group). Histopathological studies also indicated improvements in angiogenesis score and collagen density score in the animals treated with the V + G + group.

CONCLUSION

The results of this study showed that fibroblast cells expressing the fibromodulin gene improve wound contraction and some histological parameters in the deep wound model of the rat.

Potential Role of CD99 Signaling Pathway in Schwann Cell Dysfunction in Diabetic Foot Ulcers Based on Single-Cell Transcriptome Analysis

Background: Schwann cell (SC) dysfunction contributes to the delayed healing of diabetic foot ulcers (DFUs). However, the underlying molecular mechanism regarding the unregulated SC function is poorly understood. Thus, we examined the single-cell transcriptome data from different DFU states focusing on SC characteristics. Methods: The single-cell RNA sequencing (scRNA-seq) data of DFU was obtained from the Gene Expression Omnibus (GEO) database, covering foot skin samples from nondiabetic patients, diabetic patients without DFU, DFU healers, and DFU nonhealers. After scRNA-seq data processing, downscaling, and cell cluster identification, cell communication analysis was performed by the CellChat package. Furthermore, we subclustered SC populations and ran the trajectory inference and pseudotime analysis to investigate the dynamic changes in SC. Finally, the significant pathways were validated with a db/db mouse wound model. Results: scRNA-seq analysis revealed different SC percentages and gene markers across the DFU groups. We identified that the CD99 signaling pathway was upregulated in the DFU nonhealer group. In the db/db mouse wound model, we observed that CD99 was highly expressed in the demyelinated area of the peripheral nerve fibers. Conclusion: Our study elucidated that the CD99 pathway activation may play a crucial role in SC dysfunction of DFU, providing insights into the peripheral glia regulation mechanism and potential therapeutic target of DFU.

Resveratrol Promotes Wound Healing by Enhancing Angiogenesis via Inhibition of Ferroptosis

Diabetic wound healing critically depends on functional endothelial cells for angiogenesis, yet the hyperglycemic microenvironment induces endothelial dysfunction through oxidative stress, inflammation, and senescence. Although ferroptosis has been recognized as a critical pathological factor contributing to impaired diabetic wound healing, the therapeutic potential of resveratrol (Res), a natural polyphenol with well-documented antioxidant and anti-ferroptotic properties, remains underexplored in this context. This study aimed to investigate the protective effects of Res on endothelial cells and elucidate its underlying mechanisms in diabetic wound healing. In vitro experiments systematically evaluated Res's impact on cellular inflammatory responses, senescence levels, and angiogenic capacity. Subsequent in vivo studies assessed Res's therapeutic potential by monitoring diabetic wound healing progression and analyzing associated histological changes. To clarify the mechanisms underlying Res's promotion of diabetic wound healing, we conducted comprehensive analyses measuring intracellular reactive oxygen species, lipid peroxidation levels, mitochondrial membrane potential and morphology, ferroptosis-related marker expression, and upstream signaling pathway regulation. Res significantly reduced HG-induced inflammatory responses and cellular senescence in human umbilical vein endothelial cells while enhancing their angiogenic potential in vitro. In vivo results showed that Res not only markedly accelerated diabetic wound healing but also demonstrated multiple beneficial effects, including effective suppression of cellular senescence, decreased ferroptosis levels, and significantly promoted angiogenesis. Mechanistic investigations confirmed that Res achieves these effects by inhibiting ferroptosis through activation of the PI3K-AKT-Nrf2 signaling axis. Our results demonstrate that Res protects endothelial cells from HG-induced ferroptosis by activating PI3K-AKT-Nrf2 signaling, thereby promoting angiogenesis and diabetic wound healing. These findings highlight Res as a promising therapeutic candidate for impaired diabetic wound repair and justify further clinical investigation.

Dihydroartemisinin Targets the NFIC/FBN1 Cascade to Enhance Wound Healing in Chronic Skin Ulcer by Inhibiting Fibroblast Ferroptosis

Dysfunction of fibroblasts contributes to a pathological state to delay wound repair in chronic skin ulcer (CSU). Dihydroartemisinin (DHA), a derivative of artemisinin, has a therapeutic potential in diverse diseases owing to multiple pharmacological effects. However, no attempt was made to evaluate the function of DHA in CSU. Human dermal fibroblasts were isolated from the peripheral ulcerative tissues in CSU patients (uHFBs) and normal skins (nHFBs). Cell migration, proliferation, apoptosis, and ability were detected. Ferroptosis was evaluated by detecting Fe2+, iron and ROS contents. Immunoblot and quantitative PCR analyses were performed to quantify expression. The NFIC/FBN1 binding relationship was verified by luciferase reporter assay. The CSU mouse model was established, and histology and Masson's staining was used to analyze DHA efficacy. DHA increased NFIC expression in uHFBs. DHA accelerated cell proliferation and migration and impeded ferroptosis in uHFBs, which could be partially counteracted by NFIC reduction. Mechanistically, NFIC transcriptionally elevated FBN1 expression, and DHA increased FBN1 expression by NFIC. NFIC increase enhanced uHFB proliferation and migration and suppressed ferroptosis, which could be abrogated by FBN1 downregulation. Moreover, DHA improved wound repair in CSU mice by upregulating NFIC and FBN1. Additionally, NFIC and FBN1 were underexpressed in uHFBs versus nHFBs. Our findings indicate that DHA has the efficacy to improve wound repair in CSU mice and upgrades skin fibroblast function via the NFIC/FBN1 cascade. DHA may be a novel drug for CSU treatment.

Mechanisms and therapeutic opportunities in metabolic aberrations of diabetic wounds: a narrative review

Metabolic aberrations are fundamental to the complex pathophysiology and challenges associated with diabetic wound healing. These alterations, induced by the diabetic environment, trigger a cascade of events that disrupt the normal wound-healing process. Key factors in this metabolic alternation include chronic hyperglycemia, insulin resistance, and dysregulated lipid and amino acid metabolism. In this review, we summarize the underlying mechanisms driving these metabolic changes in diabetic wounds, while emphasizing the broad implications of these disturbances. Additionally, we discuss therapeutic approaches that target these metabolic anomalies and how their integration with existing wound-healing treatments may yield synergistic effects, offering promising avenues for innovative therapies.

Uncovering the Role of Tertiary Lymphoid Organs in the Inflammatory Landscape: A Novel Immunophenotype of Diabetic Foot Ulcers

Diabetes foot ulcers (DFU) are the most common foot injuries leading to lower extremity amputation. Our study aimed to provide the first representative analysis highlighting the vital role of Tertiary Lymphoid Organs (TLO) inflammatory landscape in diabetic foot ulcers. The study explores mechanisms of TLO formation and the disease-specific roles of TLOs in regulating peripheral inflammatory and immune responses. Additionally, comprehensive analysis of clinical data from DFU cases, focused on TLO pathophysiology and systemic immune-inflammation landscape, is documented, aiming to identify the risk factors contributing to the development of DFUs. Our experimental results showed very significant differences were observed among the IL-17 and IFN-γ cytokine levels between the DFU vs. Control and DFU vs. NIDFU (Non-Infectious Diabetic Foot Ulcers) groups, while minimal differences were observed in IL-6 and TNF-α cytokine levels. Immunohistochemistry staining or Immunophenotyping of DFU patient-derived wound samples for TLO inflammatory stratification showed remarkable differences between DFU, NIDFU, and control groups both in CD3+ T Cells and CD20+ B cells. Overall, our study findings highlight the perspective role of TLO in DFU mechanisms and its prudent role in regulating peripheral inflammatory-immune responses. TLO study-related significant findings might be one of the important mechanisms, and its effective unveil might be a valuable treatment modality for DFU-complications.

Microenvironment of diabetic foot ulcers: Implications for healing and therapeutic strategies

Diabetic foot ulcers (DFUs) are a common yet serious complication in individuals with diabetes, often presenting as chronic, nonhealing wounds that significantly impair quality of life. The healing process of DFUs is largely influenced by the local microenvironment, which encompasses factors such as hypoxia, inflammation, and the involvement of various cell types. Poor blood circulation in the affected area results in hypoxia, compromising cellular function and restricting nutrient supply, thereby delaying wound healing. In addition, chronic inflammation disrupts immune system balance, with excessive pro-inflammatory cytokines not only failing to facilitate tissue repair but also exacerbating tissue damage. Moreover, key cell types, including fibroblasts, keratinocytes, and macrophages, play crucial roles at different stages of the healing process, contributing to collagen production and skin regeneration. A comprehensive understanding of the complex dynamics within the DFU microenvironment is essential for developing more precise therapeutic approaches, such as advanced drug delivery systems and bioactive materials, aimed at promoting wound healing and reducing the risk of recurrence.

Flavonoids in Lotus Stamen Extract Inhibit High Glucose-Induced Intracellular Glycation in Fibroblasts by Upregulating the Expression of Glyoxalase 1 and Alleviating Oxidative Stress

Glycation is a process in which reducing sugars bind to proteins, resulting in the formation of advanced glycation end products (AGEs). These AGEs accumulate in the skin, promote excessive collagen crosslinking, and disrupt the extracellular matrix (ECM), impairing normal cellular functions and contributing to skin aging. To evaluate the anti-glycation efficacy of lotus stamen extract (LSE), we employed the BSA-fructose system and a high glucose (HG)-induced fibroblast glycation model. The results demonstrated that LSE effectively inhibited cellular glycation and also exhibited anti-inflammatory, antioxidative, and anti-senescent effects in HG-induced human skin fibroblasts (HSF). Further investigation into the anti-glycation mechanism and component analysis of the lotus stamen ethyl acetate extract (LSEE) led to the identification of 15 flavonoids. The anti-glycation results indicated that these flavonoids are likely the primary active constituents in LSE. Mechanistic studies revealed that GLO1 plays a crucial role in cellular resistance to glycation, and LSEE enhanced GLO1 expression through the Nrf2/Keap1 pro-survival pathway, thereby mitigating intracellular AGE production. In summary, LSEE and its multiple flavonoid components exhibit potent intracellular anti-glycation activity and present significant potential to be developed as a natural and organic product for cosmetic and healthcare applications.

N6-methyladenosine methyltransferase Wilms tumor 1-associated protein impedes diabetic wound healing through epigenetically activating DNA methyltransferase 1

BACKGROUND

Diabetic wound injury is a significant and common complication in individuals with diabetes. N6-methyladenosine (m6A)-related epigenetic regulation is widely involved in the pathogenesis of diabetes complications. However, the function of m6A methyltransferase Wilms tumor 1-associated protein (WTAP) in diabetic wound healing remains elusive.

AIM

To investigate the potential epigenetic regulatory mechanism of WTAP during diabetic wound healing.

METHODS

Human umbilical vein endothelial cells (HUVECs) were induced with high glucose (HG) to establish in vitro cell model. Male BALB/c mice were intraperitoneally injected with streptozotocin to mimic diabetes, and full-thickness excision was made to mimic diabetic wound healing. HG-induced HUVECs and mouse models were treated with WTAP siRNAs and DNA methyltransferase 1 (DNMT1) overexpression vectors. Cell viability and migration ability were detected by cell counting kit-8 and Transwell assays. In vitro angiogenesis was measured using a tube formation experiment. The images of wounds were captured, and re-epithelialization and collagen deposition of skin tissues were analyzed using hematoxylin and eosin staining and Masson's trichrome staining.

RESULTS

The expression of several m6A methyltransferases, including METTL3, METTL14, METTL16, KIAA1429, WTAP, and RBM15, were measured. WTAP exhibited the most significant elevation in HG-induced HUVECs compared with the normal control. WTAP depletion notably restored cell viability and enhanced tube formation ability and migration of HUVECs suppressed by HG. The unclosed wound area of mice was smaller in WTAP knockdown-treated mice than in control mice at nine days post-wounding, along with enhanced re-epithelialization rate and collagen deposition. The m6A levels on DNMT1 mRNA in HUVECs were repressed by WTAP knockdown in HUVECs. The mRNA levels and expression of DNMT1 were inhibited by WTAP depletion in HUVECs. Overexpression of DNMT1 in HUVECs notably reversed the effects of WTAP depletion on HG-induced HUVECs.

CONCLUSION

WTAP expression is elevated in HG-induced HUVECs and epigenetically regulates the m6A modification of DNMT1 to impair diabetic wound healing.

Conditioned medium of engineering macrophages combined with soluble microneedles promote diabetic wound healing

Diabetic wounds have a profound effect on both the physical and psychological health of patients, highlighting the urgent necessity for novel treatment strategies and materials. Macrophages are vital contributors to tissue repair mechanisms. Macrophage conditioned medium contains various proteins and cytokines related to wound healing, indicating its potential to improve recovery from diabetic wound. Engineering macrophages may enable a further improvement in their tissue repair capacity. Fibroblast growth factor 2 (FGF2) is a crucial growth factor that plays an integral role in wound healing process. And in this study, a stable macrophage cell line (engineered macrophages) overexpressing FGF2 was successfully established by engineering modification of macrophages. Proteomic analysis indicated that conditioned medium derived from FGF2 overexpressed macrophages may promote wound healing by enhancing the level of vascularization. Additionally, cellular assays demonstrated that this conditioned medium promotes endothelial cell migration in vitro. For the convenience of drug delivery and wound application, we prepared soluble hyaluronic acid microneedles to load the conditioned medium. These soluble microneedles exhibited excellent mechanical properties and biocompatibility while effectively releasing their contents in vivo. The microneedles significantly accelerated wound healing, leading to a marked increase in vascular proliferation and improved collagen deposition within a full thickness skin defect diabetic mouse model. In summary, we developed a type of hyaluronic acid microneedle loaded with conditioned medium of engineered macrophages. These microneedles have been demonstrated to enhance tissue vascularization and facilitate diabetic wound healing. This might potentially serve as a highly promising therapeutic approach for diabetic wounds.

Electrospinning strategies targeting fibroblast for wound healing of diabetic foot ulcers

The high incidence and prevalence of diabetic foot ulcers (DFUs) present a substantial clinical and economic burden, necessitating innovative therapeutic approaches. Fibroblasts, characterized by their intrinsic cellular plasticity and multifunctional capabilities, play key roles in the pathophysiological processes underlying DFUs. Hyperglycemic conditions lead to a cascade of biochemical alterations that culminate in the dysregulation of fibroblast phenotype and function, which is the primary cause of impaired wound healing in DFUs. Biomaterials, particularly those engineered at the nanoscale, hold significant promise for enhancing DFU treatment outcomes. Electrospun nanofiber scaffolds, with their structural and compositional similarities to the natural extracellular matrix, serve as an effective substrate for fibroblast adhesion, proliferation, and migration. This review comprehensively summarizes the biological behavior of fibroblasts in DFUs and the mechanism mediating wound healing. At the same time, the mechanism of biological materials, especially electrospun nanofiber scaffolds, to improve the therapeutic effect by regulating the activity of fibroblasts was also discussed. By highlighting the latest advancements and clinical applications, we aim to provide a clear perspective on the future direction of DFU treatment strategies centered on fibroblast-targeted therapies.

Exosomes derived from fibroblasts in DFUs delay wound healing by delivering miR-93-5p to target macrophage ATG16L1

Diabetes is an extremely costly disease, one-third of which are attributed to the management of diabetic foot disease including chronic, non-healing, diabetic foot ulcers (DFUs). Therefore, much effort is needed to understand the pathogenesis of DFUs and novel therapeutics. We utilized exosome staining to confirm the interaction between fibroblast-derived exosomes and macrophages. Subsequently, we employed public data and qPCR to screen for upregulated miRNAs in fibroblast-derived exosomes in DFUs. The relationship between was validate miR-93-5 and ATG16L1 through data prediction and dual-luciferase reporter assays. A variety of molecular biology experiments were used for subsequent pathway validation. Additionally, we established Atg16l1MKI and Nlrp3MKO mice for further validation. We identified that miR-93-5p derived from fibroblasts played an important role in M1 macrophages polarization. Predicted by database, we found that miR-93-5p can bind to ATG16L1 mRNA, thereby influencing macrophage autophagy mediated by ATG16L1 in the clearance of ROS, thus activating the NLRP3 signaling pathway. In vivo, miR-93-5p antagomir treatment accelerated diabetic wound healing and induced M2 macrophage polarization. Fibroblasts and macrophages show cell crosstalk during the development of DFUs by miR-93-5p, and that antagomir treatment may be a promising and technically advantageous alternative to DFUs therapies.

Facilitation of diabetic wound healing by far upstream element binding protein 1 through augmentation of dermal fibroblast activity

AIMS

Diabetes mellitus (DM) often leads to wound healing complications, partly attributed to the accumulation of advanced glycosylation end products (AGEs) that impair fibroblast function. Far Upstream Element Binding Protein 1 (FUBP1) regulates cell proliferation, migration, and collagen synthesis. However, the impact of FUBP1 on diabetic wound healing remains unknown. This study is designed to explore the function and mechanisms of FUBP1 in diabetic wound healing.

METHODS

Eighteen Sprague-Dawley rats (weighing 220-240 g) were randomly assigned to three groups (n = 6): a control group (NC) of healthy rats, a model group (DM) of untreated diabetic rats, and a treatment group (DM + FUBP1) of diabetic rats accepting FUBP1 treatment. A 10 mm diameter circular full-thickness skin defect was created on the back of each rat. On days 1 and 7, rats in the treatment group received local injections of 5 µg FUBP1 protein at the wound site, whereas the control group and model group were administered saline. Wound healing was documented on days 0, 3, 7, 10, and 14, with tissue samples from the wound areas collected on day 14 for histological analysis, including H&E staining, Masson's trichrome staining, and immunohistochemistry. Western blot analysis was utilized to assess the expression of GSK-3β, Wnt3a, and β-catenin. In vitro, the effects of various concentrations of AGEs on cell viability and FUBP1 expression were examined in human dermal fibroblasts (HDF). Cells were genetically modified to overexpress FUBP1 using lentiviral vectors and were cultured for 48 h in media with or without AGEs. The impacts on fibroblast proliferation, migration, and Wnt/β-catenin signaling were evaluated using CCK-8, scratch assays, and Western blot analysis.

RESULTS

Animal investigation revealed that from day 7 onwards, the wound healing rate of the treatment group was higher than that of the model group but lower than the control group. On day 14, the wound healing rates were as follows: control group (0.97 ± 0.01), model group (0.84 ± 0.03), and treatment group (0.93 ± 0.01). These differences were statistically significant. Histological analysis indicates that FUBP1 promotes granulation tissue formation, re-epithelialization, and collagen deposition in treatment group. Additionally, FUBP1 protein expression decreased in dermal fibroblasts when exposed to AGEs. Overexpression of FUBP1 significantly enhanced fibroblast proliferation and migration, activating the Wnt/β-catenin pathway and mitigating the inhibitory effects of AGEs.

CONCLUSIONS

Our results suggest that FUBP1 can be a promising therapeutic target for diabetic wound healing, potentially counteracting the detrimental effects of AGEs on dermal fibroblasts through the Wnt/β-catenin pathway.

Gentiopicroside targeting AKT1 activates HIF-1α/VEGF axis promoting diabetic ulcer wound healing

Backgound

Gentiopicroside (GSP) have been proven to accelerate the healing of diabetic ulcers (DU), but the underlying molecular mechanisms remain unclear. This study aims to explore the mechanism by which GSP accelerates the healing of DU.

Method

The targets of GSP were firstly predicted using the SuperPred, SwissTargetPrediction, and Pharmmapper databases; DU-related transcriptome data were obtained from the GEO database, including GSE147890, GSE68183, and GSE199939; differential expression analysis was conducted using the Limma package, and DU-related targets were identified after summarization and de-duplication. Then, Potential targets for GSP treatment of DU were screened by Venn analysis; core targets for GSP treatment of DU were selected by constructing a protein-protein interaction (PPI) network; the mechanism of GSP treatment of DU was predicted by GO and KEGG enrichment analysis. Finally, the target binding of GSP to core targets was evaluated by molecular docking and CETSA assay, and in vitro experiments were conducted using L929 cells to validate the findings.

Result

A total of 538 targets of GSP and 10795 DU-related targets were predicted; Venn analysis identified 215 potential targets for GSP to accelerate DU wound healing; PPI network analysis suggested that AKT1 may be core targets for GSP treatment of DU; GO and KEGG enrichment analysis showed that pathways such as HIF-1 and VEGF are closely related to the treatment of DU with GSP, and it also participates in the regulation of various biological processes such as small molecule catabolism and leukocyte migration to exert its therapeutic effect on DU. Molecular docking and CETSA detection indicated that GSP can target bind to AKT1. The experimental results confirmed that GSP can significantly promote the proliferation and migration of L929 cells. Westen Blot results showed that GSP can accelerate DU wound healing via AKT1/HIF-1α/VEGF axis.

Conclusion

GSP target binding to AKT1 accelerates DU wound healing via the regulation of HIF-1α/VEGF axis.

CXXC5 function blockade promotes diabetic wound healing through stimulating fibroblast and vascular endothelial cell activation

BACKGROUND

Extracellular matrix (ECM) and angiogenesis are critical controls of wound regeneration, and their dysfunction delays diabetes recovery. CXXC5 belongs to the CXXC protein family that can regulate the function of human dermal fibroblasts (HDFs) and human umbilical vein endothelial cells (HUVECs); However, awareness of its functional role remains limited.

METHODS

Mice were divided into control (CON), diabetic (DM), diabetic + KY19382 (DM + KY19382), and diabetic + vehicle (DM + Vehicle) groups. HDFs and HUVECs were stimulated under different CXXC5 conditions and mice were treated with KY19382, followed by the application of assays including Western blotting (WB), immunofluorescence (IF) and quantitative reverse transcription-PCR (qRT-PCR) to assess wound healing and molecular signaling.

RESULTS

Mice in DM had fewer blood vessels, a slower wound healing rate, and more disrupted collagen than CON. Application of KY19382 improved these conditions, which promoted fibroblast activation and vascularization in high glucose environments and DM. Mechanistically, blocking CXXC5 promotes Wnt/β-catenin-mediated stabilization by reducing the binding of the deterrent factor CTBP1 to β-catenin, which induces dermal fibroblast activation and facilitates HUVECs tube formation and migration via VEGFA/VEGFR2 and NFκB signaling pathways. KY19382 promotes HUVECs activation by blocking CTBP1 transcription to activate the NFκB signaling pathway, thus wound re-vascularization.

CONCLUSION

CXXC5 is an essential regulatory factor of wound healing and a prospective therapeutic target for treating chronic wound damage in diabetes.

Negative pressure wound therapy promotes wound healing by down-regulating miR-155 expression in granulation tissue of diabetic foot ulcers

Our study aims to investigate the effect of negative pressure wound therapy (NPWT) on microRNA-155 (miR-155) in the granulation tissue of patients suffering from diabetic foot ulcers (DFUs) and its correlation with wound healing. A total of sixty patients diagnosed with DFUs were randomly assigned to either the NPWT group (n = 40) or the Non-NPWT group (n = 20) in a 2:1 ratio. After debridement, the NPWT group received NPWT treatment for one week, while the Non-NPWT group underwent routine dressing therapy. The expression of miR-155 in DFU granulation tissues was evaluated by qRT-PCR before and after treatment for one week. Following termination, wound healing rates were assessed in the NPWT group, and the correlation between variations in miR-155 expression (ΔmiR-155) and wound healing was analyzed pre and post NPWT treatment. In vitro experiments were conducted to investigate the effects of negative pressure on variations of miR-155 expression, as well as proliferation, migration, and apoptosis in normal human dermal fibroblasts (NHDFs). The NPWT group showed a decrease in miR-155 expression in wound granulation tissue compared with pre-treatment [4.12 (1.22, 14.85) vs. 6.83 (2.15, 15.72), P < 0.05]. Conversely, there was no statistically significant difference in miR-155 expression in wound granulation tissue between pre-treatment and post-treatment in the Non-NPWT group (P > 0.05). However, analysis revealed a positive correlation between ΔmiR-155 and wound healing rate after 4 weeks in the NPWT group (χ2 = 4.829, P = 0.028). The in vitro experiments showed a significant decrease in miR-155 expression in NHDFs under negative pressure measured at -125 mmHg (P < 0.05). This reduction in miR-155 expression, in turn, enhanced the proliferation and migration ability while decreasing the apoptosis rate of NHDFs by targeting the upregulation of fibroblast growth factor 7 (FGF7) gene expression (P < 0.05). It is concluded that NPWT promotes DFU healing by reducing the expression of miR-155 in granulation tissue and the efficacy of NPWT correlated with altered miR-155 expression in wound tissue.

Adipose-Derived Stem Cell Exosomes Promote Scar-Free Healing of Diabetic Wounds via miR-204-5p/TGF-β1/Smad Pathway

Numerous researches have demonstrated the therapeutic potential of adipose-derived stem cell exosomes (ADSC-Exos) in promoting wound healing. In this study, we aimed to investigate the impact of ADSC-Exos on diabetic wound fibroblasts and elucidate its possible mechanisms. CCK-8, Edu, cell scratch, and Transwell tests were used to evaluate the function of ADSC-Exos on rat skin fibroblasts (RSFs) in high-glucose (HG) medium. The targeting effect of ADSC-Exo-derived microRNA (miRNA) and TGF-β1 was assessed using bioinformatic analysis and then confirmed with western blot and dual luciferase reporter assays. ADSC-Exos, miR-204-5p mimic, and anti-miR-204-5p mimic were used to stimulate RSFs, and the levels of TGF-β1/Smad pathway were analyzed by western blot. In vivo, digital photo and tissue section staining were used to evaluate the therapeutic effect of ADSC-Exos on diabetic wounds. The data showed that ADSC-Exos enhance the proliferation and migration of fibroblasts under HG conditions, reduce excessive myofibroblast differentiation and collagen deposition, and promote scarless healing of diabetic wounds. Additionally, miR-204-5p in ADSC-Exos targets TGF-β1 to inhibit p-Smad2/3, Col I, and alpha-smooth muscle actin (α-SMA), thereby reducing fibrosis. These findings suggest that ADSC-Exos have potential prospects for promoting diabetic wound healing.

Research Hotspots and Frontier Trends of Autophagy in Diabetic Cardiomyopathy From 2014 to 2024: A Bibliometric Analysis

Objective

In recent years, the investigation of autophagy mechanisms has gained prominence as a key focus for understanding the pathogenesis and therapeutic potential of diabetic cardiomyopathy. This study aims to present an overview of the current state, major research areas, and emerging trends in autophagy related to diabetic cardiomyopathy through bibliometric analysis, offering a scientific foundation for future research.

Methods

The Web of Science Core Collection served as the data source for this study, from which full-text publications were extracted. Using CiteSpace 6.3.R1, VOSviewer v1.6.18, and R-Bibliometrix, the analysis evaluated research output across dimensions such as subjects, countries, institutions, journals, authors, and co-cited references, generating a comprehensive visual map.

Results

A total of 367 publications met the inclusion criteria. Between 2014 and 2024, the volume of articles demonstrated a consistent upward trajectory. Research on autophagy in diabetic cardiomyopathy predominantly spans the disciplines of biology and medicine. China and the Fourth Military Medical University emerged as leading contributors among 41 countries and 505 institutions. Sun Dongdong was identified as the most prolific author, while Jia GH was the most frequently cited. Key journals in this field include Biochimica et Biophysica Acta - Molecular Basis of Disease and Frontiers in Cardiovascular Medicine, while Circulation Research recorded the highest number of co-citations. The most cited reference was an experimental study by Xie ZL. Current research focuses on autophagy, diabetic cardiomyopathy, oxidative stress, and their underlying mechanisms.

Conclusion

Research on the role of autophagy in diabetic cardiomyopathy has reached a stable phase of development. Future investigations should prioritize mechanistic studies and emphasize the clinical application of novel pharmacological interventions, thereby advancing therapeutic strategies and contributing to improved human health outcomes.

Amine-Functionalized Gellan Gum-Based Hydrogel Loaded with Adipose Stem Cell-Derived Small Extracellular Vesicles: An In Vitro Proof of Concept for Enhancing Diabetic Foot Ulcer Healing

Diabetic foot ulcers (DFUs) are chronic wounds and a common complication of diabetes. A promising strategy in the treatment of DFUs involves the use of stem cell derivatives, such as small extracellular vesicles (sEVs), which can enhance cell proliferation and reduce inflammation while avoiding immunogenic responses. In this study, we evaluated the ability of adipose mesenchymal stem cell- (ASC)-derived sEVs to enhance the proliferation of human fibroblasts, which play a crucial role in wound regenerative processes. To mimic the inflammatory environment of DFUs, fibroblasts were cultured into the gellan gum (GG) modified with ethylenediamine (EDA) hydrogel scaffolds loaded with ASC-derived sEVs, under pro-inflammatory cytokines. Our comparative analysis demonstrated that sEVs loaded in GG-EDA hydrogel improved fibroblast viability in pro-inflamed conditions while retaining the anti-inflammatory and immunomodulatory properties of their cells of origin. By modulating the gene expression profile of fibroblasts to promote cell proliferation, wound healing and re-epithelialization, our system presents a promising therapeutic strategy for DFU healing.

Elucidating the dual roles of apoptosis and necroptosis in diabetic wound healing: implications for therapeutic intervention

Wound healing is a complex and multistep biological process that involves the cooperation of various cell types. Programmed cell death, including apoptosis and necrotizing apoptosis, plays a crucial role in this process. Apoptosis, a controlled and orderly programmed cell death regulated by genes, helps eliminate unnecessary or abnormal cells and maintain internal environmental stability. It also regulates various cell functions and contributes to the development of many diseases. In wound healing, programmed cell death is essential for removing inflammatory cells and forming scars. On the other hand, necroptosis, another form of programmed cell death, has not been thoroughly investigated regarding its role in wound healing. This review explores the changes and apoptosis of specific cell groups during wound healing after an injury and delves into the potential underlying mechanisms. Furthermore, it briefly discusses the possible mechanisms linking wound inflammation and fibrosis to apoptosis in wound healing. By understanding the relationship between apoptosis and wound healing and investigating the molecular mechanisms involved in apoptosis regulation, new strategies for the clinical treatment of wound healing may be discovered.

B cells recruitment promotes M2 macrophage polarization to inhibit inflammation during wound healing

Wound healing causes heavy economic burdens for families and society, becoming a critical issue in the global healthcare system. While the role of immune cells in the wound-healing process is well-established, the involvement of B cells remains poorly understood. This study aims to elucidate the essentiality of B cells in wound repair. Our findings demonstrate a rise in B-cell population during the early stage of wound healing, which further intensifies during the later stage. We employed anti-CD20 antibodies to deplete B cells in mice and created a whole skin excisional wound mice model, analyzing wound closure over 12 days. B cells were isolated from the animals' spleen and co-cultured with macrophages from bone marrow. The polarization of M1 and M2 macrophages was analyzed by real-time qPCR and flow cytometry. The wound healing process in mice was observed to be considerably delayed following the elimination of B cells. The wounds exhibited a state of inflammation primarily characterized by the presence of pro-inflammatory M1 macrophages. The decrease in M2 macrophages within the local wound area resulted in impairment of the wound repair mechanism. B-cell-macrophage co-culture system revealed that B cells effectively induce the polarization of macrophages towards M2-like phenotype. Furthermore, we found that follicular B cells play predominant role in modulating the polarization of M2 macrophages. Consequently, our findings indicate that B cells can be recruited to the wound site and facilitate the polarization of M2-like macrophages, thereby accelerating the healing process during wound healing.

Analysis of immune cell activation in patients with diabetes foot ulcer from the perspective of single cell

BACKGROUND

Diabetes mellitus (DM) can cause severe complications, including diabetic foot ulcers (DFU). There is a significant gap in understanding the single-cell ecological atlas of DM and DFU tissues.

METHODS

Single-cell RNA sequencing data were used to create a detailed single-cell ecological landscape of DM and DFU. Enrichment analysis identified pathways involved in cellular subpopulations, and pseudo-time analysis inferred cell development processes. A gene regulatory network explored the role of transcription factors in DFU progression, and a potential herbal drug-target gene interaction network was constructed.

RESULTS

In the DFU group, immune cells were activated, with notable changes in several subpopulations. ATP5E was significantly overexpressed in Naive T cells, fibroblasts, endothelial cells, and CD8+ T cells in DM patients. Specific immune cell subsets, such as Naive T_RGCC, CTL_TYROBP_CL4, Mac_SLC40A1, and M1_CCL3L1, likely contribute to DFU formation through overactivation and proliferation, leading to tissue damage and ulcer exacerbation. Key genes TPP1, TLR4, and RIPK2 were identified, and 88 active ingredients in the herbal drug-target network showed strong correlations with these targets. Herbs like Angelica dahurica, Angelica sinensis, Boswellia carterii, liquorice, myrrh, and Semen armeniacae amarae were included.

CONCLUSIONS

This study offers insights into DM and DFU cytology. T cells in DFU are activated, attacking normal tissues and worsening tissue damage. The ATP5E gene may be related to the ecological remodeling of DM, and TPP1, TLR4, and RIPK2 are potential targets for DFU treatment.

Predictive Value of Preoperative Pain Sketches in Lower Extremity Amputees Undergoing Secondary Targeted Muscle Reinnervation for Treatment of Neuropathic Pain

BACKGROUND

Targeted muscle reinnervation (TMR) is an effective surgical treatment for neuropathic pain in amputees. Qualitative descriptions of pain, depicted by pain sketches, could enhance the understanding of symptomatic improvement after surgery. Our aim is to assess whether preoperative pain sketches, drawn by lower extremity (LE) amputees, can predict surgical outcomes after secondary TMR surgery.

STUDY DESIGN

Eligible patients were LE amputees who underwent secondary TMR surgery between 2017 and 2023. Pain sketches and pain scores were prospectively collected both before and after surgery. The pain trajectory, as categorized by preoperative pain sketches, was analyzed and assessed for improvement, defined as reaching the minimal clinically important difference. The transition into different pain sketches and the occurrence of phantom drawings were evaluated for their association with improvement.

RESULTS

Fifty-eight patients were included, of which 18 (31.1%) depicted diffuse pain, 26 (44.8%) depicted focal pain (FP), and 18 (24.1%) depicted radiating pain (RP) in their preoperative sketch. FP sketches were associated with the lowest pre- and postoperative pain scores and most frequently developed into sketches indicating "no pain." RP sketches were associated with the least pain improvement, the lowest likelihood of achieving the minimal clinically important difference, and were more prevalent in patients with diabetes or depression. RP sketches were associated with phantom drawings; no other sketch types developed into RP sketches at the final follow-up.

CONCLUSIONS

In LE amputees who underwent secondary TMR, preoperative pain sketches could serve as a helpful tool in predicting pain outcomes. RP sketches seemed to be associated with worse outcomes and FP sketches with the most improvement.

Neuroma morphology: A macroscopic classification system

INTRODUCTION/AIMS

Neuromas come in different shapes and sizes; yet the correlation between neuroma morphology and symptomatology is unknown. Therefore, we aim to investigate macroscopic traits of excised human neuromas and assess the validity of a morphological classification system and its potential clinical implications.

METHODS

End-neuroma specimens were collected from prospectively enrolled patients undergoing symptomatic neuroma surgery. Protocolized images of the specimens were obtained intraoperatively. Pain data (Numeric rating scale, 0-10) were prospectively collected during preoperative interview, patient demographic and comorbidity factors were collected from chart review. A morphological classification is proposed, and the inter-rater reliability (IRR) was assessed. Distribution of neuroma morphology with patient factors, was described.

RESULTS

Forty-five terminal neuroma specimens from 27 patients were included. Residual limb patients comprised 93% of the population, of which 2 were upper (8.0%) and 23 (92.0%) were lower extremity residual limb patients. The proposed morphological classification, consisting of three groups (bulbous, fusiform, atypical), demonstrated a strong IRR (Cohen's kappa = 0.8). Atypical neuromas demonstrated higher preoperative pain, compared with bulbous and fusiform. Atypical morphology was more prevalent in patients with diabetes and peripheral vascular disease.

DISCUSSION

A validated morphological classification of neuroma is introduced. These findings may assist surgeons and researchers with better understanding of symptomatic neuroma development and their clinical implications. The potential relationship of neuroma morphology with the vascular and metabolic microenvironment requires further investigation.

Machine learning-driven discovery of novel therapeutic targets in diabetic foot ulcers

BACKGROUND

To utilize machine learning for identifying treatment response genes in diabetic foot ulcers (DFU).

METHODS

Transcriptome data from patients with DFU were collected and subjected to comprehensive analysis. Initially, differential expression analysis was conducted to identify genes with significant changes in expression levels between DFU patients and healthy controls. Following this, enrichment analyses were performed to uncover biological pathways and processes associated with these differentially expressed genes. Machine learning algorithms, including feature selection and classification techniques, were then applied to the data to pinpoint key genes that play crucial roles in the pathogenesis of DFU. An independent transcriptome dataset was used to validate the key genes identified in our study. Further analysis of single-cell datasets was conducted to investigate changes in key genes at the single-cell level.

RESULTS

Through this integrated approach, SCUBE1 and RNF103-CHMP3 were identified as key genes significantly associated with DFU. SCUBE1 was found to be involved in immune regulation, playing a role in the body's response to inflammation and infection, which are common in DFU. RNF103-CHMP3 was linked to extracellular interactions, suggesting its involvement in cellular communication and tissue repair mechanisms essential for wound healing. The reliability of our analysis results was confirmed in the independent transcriptome dataset. Additionally, the expression of SCUBE1 and RNF103-CHMP3 was examined in single-cell transcriptome data, showing that these genes were significantly downregulated in the cured DFU patient group, particularly in NK cells and macrophages.

CONCLUSION

The identification of SCUBE1 and RNF103-CHMP3 as potential biomarkers for DFU marks a significant step forward in understanding the molecular basis of the disease. These genes offer new directions for both diagnosis and treatment, with the potential for developing targeted therapies that could enhance patient outcomes. This study underscores the value of integrating computational methods with biological data to uncover novel insights into complex diseases like DFU. Future research should focus on validating these findings in larger cohorts and exploring the therapeutic potential of targeting SCUBE1 and RNF103-CHMP3 in clinical settings.

Endogenous/exogenous stimuli‐responsive smart hydrogels for diabetic wound healing

Diabetes significantly impairs the body's wound‐healing capabilities, leading to chronic, infection‐prone wounds. These wounds are characterized by hyperglycemia, inflammation, hypoxia, variable pH levels, increased matrix metalloproteinase activity, oxidative stress, and bacterial colonization. These complex conditions complicate effective wound management, prompting the development of advanced diabetic wound care strategies that exploit specific wound characteristics such as acidic pH, high glucose levels, and oxidative stress to trigger controlled drug release, thereby enhancing the therapeutic effects of the dressings. Among the solutions, hydrogels emerge as promising due to their stimuli‐responsive nature, making them highly effective for managing these wounds. The latest advancements in mono/multi‐stimuli‐responsive smart hydrogels showcase their superiority and potential as healthcare materials, as highlighted by relevant case studies. However, traditional wound dressings fall short of meeting the nuanced needs of these wounds, such as adjustable adhesion, easy removal, real‐time wound status monitoring, and dynamic drug release adjustment according to the wound's specific conditions. Responsive hydrogels represent a significant leap forward as advanced dressings proficient in sensing and responding to the wound environment, offering a more targeted approach to diabetic wound treatment. This review highlights recent advancements in smart hydrogels for wound dressing, monitoring, and drug delivery, emphasizing their role in improving diabetic wound healing. It addresses ongoing challenges and future directions, aiming to guide their clinical adoption.

Single-cell RNA-seq in diabetic foot ulcer wound healing

Diabetic foot ulcer (DFU) is a chronic and serious complication of diabetes mellitus. It is mainly caused by hyperglycaemia, diabetic peripheral vasculopathy and diabetic peripheral neuropathy. These conditions result in ulceration of foot tissues and chronic wounds. If left untreated, DFU can lead to amputation or even endanger the patient's life. Single-cell RNA sequencing (scRNA-seq) is a technique used to identify and characterise transcriptional subpopulations at the single-cell level. It provides insight into cellular function and the molecular drivers of disease. The objective of this paper is to examine the subpopulations, genes and molecules of cells associated with chronic wounds of diabetic foot by using scRNA-seq. The paper aims to explore the wound-healing mechanism of DFU from three aspects: inflammation, angiogenesis and extracellular matrix remodelling. The goal is to gain a better understanding of the mechanism of DFU wound healing and identify possible DFU therapeutic targets, providing new insights for the application of DFU personalised therapy.

Material Technologies for Improved Diabetic Foot Ulcer (DFU) Treatment: A Questionnaire Study of Healthcare Professionals' Needs

Background/Objectives: Diabetic foot ulcers (DFUs) are a common and severe complication of diabetic patients, with significant global prevalence and associated health burdens, including high recurrence rates, lower-limb amputations, and substantial associated economic costs. This study aimed to understand the user needs of healthcare professionals treating diabetic foot ulcers for newly developed material technologies. Methods: An open-ended questionnaire was used to identify user needs, identify the limitations of current treatments, and determine the specific requirements for ideal treatment. This information was used to develop a list of key considerations for creating innovative material technologies to improve diabetic wound treatment results. Results: Most respondents indicated that they followed published treatment guidelines for DFUs but noted that treatment often required a case-specific approach. Antibiotics and surgical debridement were commonly used for infection control. The participants showed a strong preference for wound dressings with lasting antibacterial properties. Respondents identified ideal properties for new products, including ease of use, enhanced antibacterial properties, affordability, and targeted biological activity. The respondents also highlighted the importance of a holistic approach to DFU management, integrating product development with comprehensive care strategies and patient education. Conclusions: This study highlights the complexity of DFU care, emphasizing that no single product can address all treatment needs. Future materials could focus on combination therapies and specific use cases. Additionally, understanding global variations in treatment practices and educating users on the proper application of newly developed material technologies is crucial for improving the management of DFUs and patient outcomes.

Complications associated with loop ileostomy reversal delayed greater than twelve months

Diverting loop ileostomy is performed after colectomy to allow for anastomotic healing, and prevention of pelvic sepsis when an anastomotic leak occurs. There is no consensus on the optimal timing of ileostomy closure, and there is limited data on complications associated with ileostomy closure greater than 12 months after creation. The aim of this study is to investigate outcomes of delayed loop ileostomy closure greater than 12 months after creation. Patients undergoing loop ileostomy closure between 2013 and 2023 at Carilion Medical Center, in Roanoke, VA were reviewed. Cohorts compared were defined as Control Group (closure < 4 months) and Delayed Group (closure > 12 months). Demographics and outcomes were compared. Statistical comparisons were performed using either Wilcoxon rank sum test, Pearson's Chi-squared test or Fisher's exact test. Statistical modeling included binary logistic regression for 30-day readmissions and a generalized linear modeling for days till bowel function returns. Adjusted odds ratios, confidence intervals, and p-values were calculated. There were 135 patients in the Control Group and 19 patients in the Delayed Group. Demographics were similar between the groups except for a higher percentage of patients with diabetes, renal failure and history of cancer in Delayed Group (all p < 0.05). Operative time was longer for Delayed loop ileostomy closure (p < 0.05). Patients in the Delayed Group demonstrated a higher hospital readmission rate within 30 days (p < 0.05). Both groups had similar return of bowel function on post-operative day 2, similar length of stay, and similar rates of postoperative ileus (p = NS). Delayed loop ileostomy closure more than 12 months after creation does not delay return of bowel function but may lead to higher hospital readmission rates within 30 days.

The emerging modulators of non-coding RNAs in diabetic wound healing

Diabetic wound healing is a complex physiological process often hindered by the underlying metabolic dysfunctions associated with diabetes. Despite existing treatments, there remains a critical need to explore innovative therapeutic strategies to improve patient outcomes. This article comprehensively examines the roles of non-coding RNAs (ncRNAs), specifically microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs), in regulating key phases of the wound healing process: inflammation, angiogenesis, re-epithelialization, and tissue remodeling. Through a deep review of current literature, we discuss recent discoveries of ncRNAs that have been shown to either promote or impair the wound healing process in diabetic wound healing, which were not covered in earlier reviews. This review highlights the specific mechanisms by which these ncRNAs impact cellular behaviors and pathways critical to each healing stage. Our findings indicate that understanding these recently identified ncRNAs provides new insights into their potential roles in diabetic wound healing, thereby contributing valuable knowledge for future research directions in this field.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

Anti-Inflammatory and Wound Healing Properties of Different Honey Varieties from Romania and Correlations to Their Composition

The complex composition of honey plays a crucial role in wound healing, exhibiting varying effects at different stages of the healing process. This study investigated seven honey varieties sourced from different regions of Romania using in vitro experimental models developed in macrophage-like, fibroblast, and keratinocyte cell lines to explore the mechanisms by which honey promoted the healing process. This study assessed the impact of honey on inflammatory cytokine production in macrophage-like cells, cell proliferation and collagen synthesis in fibroblasts, and cell proliferation and migration in keratinocytes. Additionally, correlation analysis was conducted to examine the relationship between honey composition and its biological properties. Honey varieties presented both anti- and pro-inflammatory effects. Moreover, they displayed dose-dependent pro-proliferative effects, stimulating collagen synthesis and cell migration, thereby enhancing the re-epithelialization process. The Pearson coefficient analysis indicated a strong positive correlation between biological activities and phenolic content. Additionally, there was a medium positive correlation with the ascorbic acid content and a medium negative correlation with the glucose content in the different honey varieties. Romanian honey varieties rich in phenolics showed potential in modulating inflammation, proliferation, collagen synthesis, and cell migration, suggesting their suitability for further evaluation and development of innovative dressings for skin tissue regeneration.

Novel Factors Regulating Proliferation, Migration, and Differentiation of Fibroblasts, Keratinocytes, and Vascular Smooth Muscle Cells during Wound Healing

Chronic diabetic foot ulcers (DFUs) are a significant complication of diabetes mellitus, often leading to amputation, increased morbidity, and a substantial financial burden. Even with the advancements in the treatment of DFU, the risk of amputation still exists, and this occurs due to the presence of gangrene and osteomyelitis. Nonhealing in a chronic DFU is due to decreased angiogenesis, granulation tissue formation, and extracellular matrix remodeling in the presence of persistent inflammation. During wound healing, the proliferation and migration of fibroblasts, smooth muscle cells, and keratinocytes play a critical role in extracellular matrix (ECM) remodeling, angiogenesis, and epithelialization. The molecular factors regulating the migration, proliferation, and differentiation of these cells are scarcely discussed in the literature. The literature review identifies the key factors influencing the proliferation, migration, and differentiation of fibroblasts, keratinocytes, and vascular smooth muscle cells (VSMCs), which are critical in wound healing. This is followed by a discussion on the various novel factors regulating the migration, proliferation, and differentiation of these cells but not in the context of wound healing; however, they may play a role. Using a network analysis, we examined the interactions between various factors, and the findings suggest that the novel factors identified may play a significant role in promoting angiogenesis, granulation tissue formation, and extracellular matrix remodeling during wound healing or DFU healing. However, these interactions warrant further investigation to establish their role alone or synergistically.

The regulatory mechanisms of cerium oxide nanoparticles in oxidative stress and emerging applications in refractory wound care

Cerium oxide nanoparticles (CeNPs) have emerged as a potent therapeutic agent in the realm of wound healing, attributing their efficacy predominantly to their exceptional antioxidant properties. Mimicking the activity of endogenous antioxidant enzymes, CeNPs alleviate oxidative stress and curtail the generation of inflammatory mediators, thus expediting the wound healing process. Their application spans various disease models, showcasing therapeutic potential in treating inflammatory responses and infections, particularly in oxidative stress-induced chronic wounds such as diabetic ulcers, radiation-induced skin injuries, and psoriasis. Despite the promising advancements in laboratory studies, the clinical translation of CeNPs is challenged by several factors, including biocompatibility, toxicity, effective drug delivery, and the development of multifunctional compounds. Addressing these challenges necessitates advancements in CeNP synthesis and functionalization, novel nano delivery systems, and comprehensive bio effectiveness and safety evaluations. This paper reviews the progress of CeNPs in wound healing, highlighting their mechanisms, applications, challenges, and future perspectives in clinical therapeutics.

Human Periodontal Ligament Stem Cells (hPDLSCs) Spontaneously Differentiate into Myofibroblasts to Repair Diabetic Wounds

Advanced glycation end product (AGE) accumulation due to diabetes causes vascular and neurological lesions, delaying healing. The use of stem cells could overcome these problems. Although many studies have shown the potential beneficial effects of stem cell therapies in the treatment of chronic and refractory skin ulcers, their delivery methods are still under investigation. Human periodontal ligament stem cells (hPDLSCs) can spontaneously differentiate into myofibroblasts in specific cultures; therefore, they have the potential to effectively treat diabetic wounds and may also have applications in the field of medical cosmetics. The myofibroblastic differentiation ability of hPDLSCs in the presence of AGEs was evaluated by the expression of α-SMA and COL1A1 using RT-qPCR and WB technology. Wound healing in diabetic mice, induced by streptozotocin (STZ) and assessed using H&E staining, Masson staining, and immunohistochemical (IHC) and immunofluorescence (IF) staining, was used to validate the effects of hPDLSCs. In the wound tissues, the expression of α-SMA, COL1A1, CD31, CD206, iNOS, and vimentin was detected. The findings indicated that in H-DMEM, the expression of COL1A1 exhibited a significant decrease, while α-SMA demonstrated an increase in P7 cells, ignoring the damage from AGEs (p < 0.05). In an STZ-induced diabetic C57BL/6J mice whole-skin defect model, the healing rate of the hPDLSCs treatment group was significantly higher than that in the models (on the 7th day, the rate was 65.247% vs. 48.938%, p < 0.05). hPDLSCs have been shown to spontaneously differentiate into myofibroblasts in H-DMEM and resist damage from AGEs in both in vivo and in vitro models, suggesting their potential in the field of cosmetic dermatology.

Identification of potential shared gene signatures between gastric cancer and type 2 diabetes: a data-driven analysis

Background

Gastric cancer (GC) and type 2 diabetes (T2D) contribute to each other, but the interaction mechanisms remain undiscovered. The goal of this research was to explore shared genes as well as crosstalk mechanisms between GC and T2D.

Methods

The Gene Expression Omnibus (GEO) database served as the source of the GC and T2D datasets. The differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA) were utilized to identify representative genes. In addition, overlapping genes between the representative genes of the two diseases were used for functional enrichment analysis and protein-protein interaction (PPI) network. Next, hub genes were filtered through two machine learning algorithms. Finally, external validation was undertaken with data from the Cancer Genome Atlas (TCGA) database.

Results

A total of 292 and 541 DEGs were obtained from the GC (GSE29272) and T2D (GSE164416) datasets, respectively. In addition, 2,704 and 336 module genes were identified in GC and T2D. Following their intersection, 104 crosstalk genes were identified. Enrichment analysis indicated that "ECM-receptor interaction," "AGE-RAGE signaling pathway in diabetic complications," "aging," and "cellular response to copper ion" were mutual pathways. Through the PPI network, 10 genes were identified as candidate hub genes. Machine learning further selected BGN, VCAN, FN1, FBLN1, COL4A5, COL1A1, and COL6A3 as hub genes.

Conclusion

"ECM-receptor interaction," "AGE-RAGE signaling pathway in diabetic complications," "aging," and "cellular response to copper ion" were revealed as possible crosstalk mechanisms. BGN, VCAN, FN1, FBLN1, COL4A5, COL1A1, and COL6A3 were identified as shared genes and potential therapeutic targets for people suffering from GC and T2D.

Promoting Diabetic Wound Healing through a Hydrogel-Based Cascade Regulation Strategy of Fibroblast-Macrophage

The management of diabetic wounds (DWs) continues to pose a significant challenge in the field of medicine. DWs are primarily prevented from healing due to damage to macrophage efferocytosis and fibroblast dysfunction. Consequently, a treatment strategy that involves both immunoregulation and the promotion of extracellular matrix (ECM) formation holds promise for healing DWs. Nevertheless, existing treatment methods necessitate complex interventions and are associated with increased costs, for example, the use of cytokines and cell therapy, both of which have limited effectiveness. In this study, a new type of ruthenium (IV) oxide nanoparticles (RNPs)-laden hybrid hydrogel dressing with a double network of Pluronic F127 and F68 has been developed. Notably, the hybrid hydrogel demonstrates remarkable thermosensitivity, injectability, immunoregulatory characteristics, and healing capability. RNPs in hydrogel effectively regulate both fibroblasts and macrophages in a cascade manner, stimulating fibroblast differentiation while synergistically enhancing the efferocytosis of macrophage. The immunoregulatory character of the hydrogel aids in restoring the intrinsic stability of the immune microenvironment in the wound and facilitates essential remodeling of the ECM. This hydrogel therefore offers a novel approach for treating DWs through intercellular communication.

High glucose enhances fibrosis in human annulus fibrosus cells by activating mTOR, PKCδ, and NF-κB signaling pathways

Low back pain stands as a significant factor in disability, largely resulting from intervertebral disc degeneration (IVDD). High glucose (HG) levels have been implicated in the pathogenesis of IVDD. However, the detailed mechanism of HG in IVDD is largely unknown. Our clinical results revealed that fibrosis markers such as CTGF, Col1a1, ATF4, and EIF2 are highly expressed in advanced-stage IVDD patients. Stimulation of human annulus fibrosus cells (HAFCs) with HG, but not mannitol, promotes fibrosis protein production. Ingenuity Pathway Analysis in the GSE database found that the mTOR, PKCδ, and NF-κB pathways were significantly changed during IVDD. The mTOR, PKCδ, and NF-κB inhibitors or siRNAs all abolished HG-induced fibrosis protein production. In addition, treatment of HAFCs with HG enhances the activation of mTOR, PKCδ, and NF-κB pathways. Thus, HG facilitates fibrosis in IVDD through mTOR, PKCδ, and NF-κB pathways. These results underscore the critical role of HG as a fibrotic factor in the progression of IVDD.

Association between serum copper and blood glucose: a mediation analysis of inflammation indicators in the NHANES (2011-2016)

BACKGROUND

The rising prevalence of diabetes underscores the need for identifying effective prevention strategies. Recent research suggests environmental factors, particularly heavy metals like copper, significantly influence health outcomes, including diabetes, through mechanisms involving inflammation and oxidative stress. This study aims to explore how serum copper levels affect blood glucose, employing NHANES data from 2011 to 2016, to provide insights into environmental health's role in diabetes prevention and management.

METHODS

The study analyzed data from 2,318 NHANES participants across three cycles (2011-2016), focusing on those with available data on serum copper, inflammatory markers, and blood glucose levels. We utilized principal component analysis for selecting inflammatory markers, mediation analysis to examine direct and indirect effects, multiple linear regression for assessing relationships between markers and glucose levels, and weighted quantile sum regression for evaluating individual and collective marker effects, adjusting for demographic variables and serum copper.

RESULTS

Participants averaged 42.70 years of age, with a near-even split between genders. Average serum copper was 119.50 μg/dL, white blood cell count 6.82 × 109/L, and fasting blood glucose 107.10 mg/dL. Analyses identified significant mediation by inflammatory markers (especially white blood cells: 39.78%) in the copper-blood glucose relationship. Regression analyses highlighted a positive correlation between white blood cells (estimate: 1.077, 95% CI: 0.432 to 2.490, p = 0.013) and copper levels and a negative correlation for monocyte percentage (estimate: -1.573, 95% CI: 0.520 to -3.025, p = 0.003). Neutrophil percentage was notably influential in glucose levels. Sensitive analyses confirmed the study's findings.

CONCLUSION

Serum copper levels significantly impact blood glucose through inflammatory marker mediation, highlighting the importance of considering environmental factors in diabetes management and prevention. These findings advocate for public health interventions and policies targeting environmental monitoring and heavy metal exposure reduction, emphasizing the potential of environmental health measures in combating diabetes incidence.

Multifunctional antibacterial hydrogels for chronic wound management

Chronic wounds have gradually evolved into a global health challenge, comprising long-term non-healing wounds, local tissue necrosis, and even amputation in severe cases. Accordingly, chronic wounds place a considerable psychological and economic burden on patients and society. Chronic wounds have multifaceted pathogenesis involving excessive inflammation, insufficient angiogenesis, and elevated reactive oxygen species levels, with bacterial infection playing a crucial role. Hydrogels, renowned for their excellent biocompatibility, moisture retention, swelling properties, and oxygen permeability, have emerged as promising wound repair dressings. However, hydrogels with singular functions fall short of addressing the complex requirements associated with chronic wound healing. Hence, current research emphasises the development of multifunctional antibacterial hydrogels. This article reviews chronic wound characteristics and the properties and classification of antibacterial hydrogels, as well as their potential application in chronic wound management.

Mesoporous MOFs with ROS scavenging capacity for the alleviation of inflammation through inhibiting stimulator of interferon genes to promote diabetic wound healing

Excessive production of reactive oxygen species (ROS) and inflammation are the key problems that impede diabetic wound healing. In particular, dressings with ROS scavenging capacity play a crucial role in the process of chronic wound healing. Herein, Zr-based large-pore mesoporous metal-organic frameworks (mesoMOFs) were successfully developed for the construction of spatially organized cascade bioreactors. Natural superoxide dismutase (SOD) and an artificial enzyme were spatially organized in these hierarchical mesoMOFs, forming a cascade antioxidant defense system, and presenting efficient intracellular and extracellular ROS scavenging performance. In vivo experiments demonstrated that the SOD@HMUiO-MnTCPP nanoparticles (S@M@H NPs) significantly accelerated diabetic wound healing. Transcriptomic and western blot results further indicated that the nanocomposite could inhibit fibroblast senescence and ferroptosis as well as the stimulator of interferon genes (STING) signaling pathway activation in macrophages mediated by mitochondrial oxidative stress through ROS elimination. Thus, the biomimetic multi-enzyme cascade catalytic system with spatial ordering demonstrated a high potential for diabetic wound healing, where senescence, ferroptosis, and STING signaling pathways may be potential targets.

Short-Term l-arginine Treatment Mitigates Early Damage of Dermal Collagen Induced by Diabetes

Changes in the structural properties of the skin due to collagen alterations are an important factor in diabetic skin complications. Using a combination of photonic methods as an optic diagnostic tool, we investigated the structural alteration in rat dermal collagen I in diabetes, and after short-term l-arginine treatment. The multiplex approach shows that in the early phase of diabetes, collagen fibers are partially damaged, resulting in the heterogeneity of fibers, e.g., "patchy patterns" of highly ordered/disordered fibers, while l-arginine treatment counteracts to some extent the conformational changes in collagen-induced by diabetes and mitigates the damage. Raman spectroscopy shows intense collagen conformational changes via amides I and II in diabetes, suggesting that diabetes-induced structural changes in collagen originate predominantly from individual collagen molecules rather than supramolecular structures. There is a clear increase in the amounts of newly synthesized proline and hydroxyproline after treatment with l-arginine, reflecting the changed collagen content. This suggests that it might be useful for treating and stopping collagen damage early on in diabetic skin. Our results demonstrate that l-arginine attenuates the early collagen I alteration caused by diabetes and that it could be used to treat and prevent collagen damage in diabetic skin at a very early stage.

Pulsed Radiofrequency Electromagnetic Fields as Modulators of Inflammation and Wound Healing in Primary Dermal Fibroblasts of Ulcers

Venous leg ulcers are one of the most common nonhealing conditions and represent an important clinical problem. The application of pulsed radiofrequency electromagnetic fields (PRF-EMFs), already applied for pain, inflammation, and new tissue formation, can represent a promising approach for venous leg ulcer amelioration. This study aims to evaluate the effect of PRF-EMF exposure on the inflammatory, antioxidant, cell proliferation, and wound healing characteristics of human primary dermal fibroblasts collected from venous leg ulcer patients. The cells' proliferative and migratory abilities were evaluated by means of a BrdU assay and scratch assay, respectively. The inflammatory response was investigated through TNFα, TGFβ, COX2, IL6, and IL1β gene expression analysis and PGE2 and IL1β production, while the antioxidant activity was tested by measuring GSH, GSSG, tGSH, and GR levels. This study emphasizes the ability of PRF-EMFs to modulate the TGFβ, COX2, IL6, IL1β, and TNFα gene expression in exposed ulcers. Moreover, it confirms the improvement of the proliferative index and wound healing ability presented by PRF-EMFs. In conclusion, exposure to PRF-EMFs can represent a strategy to help tissue repair, regulating mediators involved in the wound healing process.

Total iridoid glycoside extract of Lamiophlomis rotata (Benth) Kudo accelerates diabetic wound healing by the NRF2/COX2 axis

BACKGROUND

Lamiophlomis rotata (Benth.) Kudo (L. rotata), the oral Traditional Tibetan herbal medicine, is adopted for treating knife and gun wounds for a long time. As previously demonstrated, total iridoid glycoside extract of L. rotata (IGLR) induced polarization of M2 macrophage to speed up wound healing. In diabetic wounds, high levels inflammatory and chemotactic factors are usually related to high reactive oxygen species (ROS) levels. As a ROS target gene, nuclear factor erythroid 2-related factor 2 (NRF2), influences the differentiation of monocytes to M1/M2 macrophages. Fortunately, iridoid glycosides are naturally occurring active compounds that can be used as the oxygen radical scavenger. Nevertheless, the influence of IGLR in diabetic wound healing and its associated mechanism is largely unclear.

MATERIALS AND METHODS

With macrophages and dermal fibroblasts in vitro, as well as a thickness excision model of db/db mouse in vivo, the role of IGLR in diabetic wound healing and the probable mechanism of the action were investigated.

RESULTS

Our results showed that IGLR suppressed oxidative distress and inflammation partly through the NRF2/cyclooxygenase2 (COX2) signaling pathway in vitro. The intercellular communication between macrophages and dermal fibroblasts was investigated by the conditioned medium (CM) of IGLR treatment cells. The CM increased the transcription and translation of collagen I (COL1A1) and alpha smooth muscle actin (α-SMA) within fibroblasts. With diabetic wound mice, the data demonstrated IGLR activated the NRF2/KEAP1 signaling and the downstream targets of the pathway, inhibited COX2/PEG2 signaling and decreased the interaction inflammatory targets of the axis, like interleukin-1beta (IL-1β), interleukin 6 (IL-6), apoptosis-associated speck-like protein (ASC), cysteinyl aspartate specific proteinase1 (caspase1) and NOD-like receptor-containing protein 3 (NLRP3).In addition, the deposition of COL1A1, and the level of α-SMA, and Transforming growth factor-β1 (TGF-β1) obviously elevated, whereas that of pro-inflammatory factors reduced in the diabetic wound tissue with IGLR treatment.

CONCLUSION

IGLR suppressed oxidative distress and inflammation mainly through NRF2/COX2 axis, thus promoting paracrine and accelerating wound healing in diabetes mice.

Modulating embryonic signaling pathways paves the way for regeneration in wound healing

Epithelial tissues, including the skin, are highly proliferative tissues with the capability to constant renewal and regeneration, a feature that is essential for survival as the skin forms a protective barrier against external insults and water loss. In adult mammalian skin, every injury will lead to a scar. The scar tissue that is produced to seal the wound efficiently is usually rigid and lacks elasticity and the skin's original resilience to external impacts, but also secondary appendages such as hair follicles and sebaceous glands. While it was long thought that hair follicles develop solely during embryogenesis, it is becoming increasingly clear that hair follicles can also regenerate within a wound. The ability of the skin to induce hair neogenesis following injury however declines with age. As fetal and neonatal skin have the remarkable capacity to heal without scarring, the recapitulation of a neonatal state has been a primary target of recent regenerative research. In this review we highlight how modulating dermal signaling or the abundance of specific fibroblast subsets could be utilized to induce de novo hair follicles within the wound bed, and thus to shift wound repair with a scar to scarless regeneration.

Fibroblasts in Diabetic Foot Ulcers

Fibroblasts are stromal cells ubiquitously distributed in the body of nearly every organ tissue. These cells were previously considered to be "passive cells", solely responsible for ensuring the turnover of the extracellular matrix (ECM). However, their versatility, including their ability to switch phenotypes in response to tissue injury and dynamic activity in the maintenance of tissue specific homeostasis and integrity have been recently revealed by the innovation of technological tools such as genetically modified mouse models and single cell analysis. These highly plastic and heterogeneous cells equipped with multifaceted functions including the regulation of angiogenesis, inflammation as well as their innate stemness characteristics, play a central role in the delicately regulated process of wound healing. Fibroblast dysregulation underlies many chronic conditions, including cardiovascular diseases, cancer, inflammatory diseases, and diabetes mellitus (DM), which represent the current major causes of morbidity and mortality worldwide. Diabetic foot ulcer (DFU), one of the most severe complications of DM affects 40 to 60 million people. Chronic non-healing DFU wounds expose patients to substantial sequelae including infections, gangrene, amputation, and death. A complete understanding of the pathophysiology of DFU and targeting pathways involved in the dysregulation of fibroblasts are required for the development of innovative new therapeutic treatments, critically needed for these patients.

Recent advances of hydrogels as smart dressings for diabetic wounds

Chronic diabetic wounds have been an urgent clinical problem, and wound dressings play an important role in their management. Due to the design of traditional dressings, it is difficult to achieve adaptive adhesion and on-demand removal of complex diabetic wounds, real-time monitoring of wound status, and dynamic adjustment of drug release behavior according to the wound microenvironment. Smart hydrogels, as smart dressings, can respond to environmental stimuli and achieve more precise local treatment. Here, we review the latest progress of smart hydrogels in wound bandaging, dynamic monitoring, and drug delivery for treatment of diabetic wounds. It is worth noting that we have summarized the most important properties of smart hydrogels for diabetic wound healing. In addition, we discuss the unresolved challenges and future prospects in this field. We hope that this review will contribute to furthering progress on smart hydrogels as improved dressing for diabetic wound healing and practical clinical application.

A multimodal therapy for infected diabetic wounds based on glucose-responsive nanocomposite-integrated microneedles

Diabetic wounds in a state of high glucose are refractory to treatment and healing, especially if they are infected with bacteria. Herein, a novel nanocomposite (CIP/GOx@ZIF-8) was synthesized by loading ciprofloxacin hydrochloride (CIP) and glucose oxidase (GOx) into zeolitic imidazole framework-8 (ZIF-8) that exhibited good glucose sensitivity and catalytic activity. The high glucose in diabetic wounds could be decomposed into hydrogen peroxide (H2O2) and gluconic acid via the catalysis of GOx, which further destroyed CIP/GOx@ZIF-8 to release Zn2+ and cargos. The combination of glucose starvation, Zn2+, H2O2 and CIP could elevate the antibacterial effect and reduce bacterial resistance. Subsequently, the nanocomposite was fabricated into dissolving microneedles (CIP/GOx@ZIF-8 MNs) using polyvinylpyrrolidone (PVP). The microneedles exhibited good mechanical strength, puncture performance, dissolving performance, glucose responsiveness, antibacterial performance and biocompatibility. For in vivo wound healing, CIP/GOx@ZIF-8 MNs with good biosafety facilitated neovascularization and collagen deposition as well as reduced inflammation, and the wounds were almost healed after treatment. This multimodal therapeutic strategy is created to provide a unique treatment for infected diabetic wounds.

Shikonin potentiates skin wound healing in Sprague-Dawley rats by stimulating fibroblast and endothelial cell proliferation and angiogenesis

BACKGROUND

Shikonin, a major component of Lithospermum erythrorhizon, exerts anti-inflammatory and antibacterial effects and expedites wound healing. This study aims to evaluate the anti-inflammatory and antioxidant activities of shikonin in a Sprague-Dawley rat model and cell models using fibroblast and endothelial cells.

METHODS

The impact of shikonin on the activity of endothelial cells and fibroblasts was examined by cell counting kit 8 and wound-healing assays. A diabetic rat model was constructed, followed by wound creation for treatment with shikonin. Hematoxylin-eosin staining was used to assess pathological changes, and Masson's trichrome method to detect collagen deposition. Immunohistochemistry using antibodies against proliferating cell nuclear antigen and CD31 was conducted to detect proliferation and vascular density. Enzyme-linked immunosorbent assay and immunohistochemistry were carried out to assess pro-inflammatory and anti-inflammatory factor concentrations. Western blot and immunofluorescence were implemented to analyze oxidative stress-related protein expression.

RESULTS

Shikonin induced the activity of both fibroblasts and endothelial cells. Shikonin treatment contributed to facilitated wound healing and higher healing rates in rats. It also resulted in faster lesion debulking in tissues, reduced inflammatory infiltration, increased collagen deposition, and enhanced angiogenesis. Detection of markers at the wounds showed that shikonin accelerated cell proliferation, enhanced tissue remodeling, and inhibited oxidative stress.

CONCLUSION

Shikonin stimulates the proliferation and migration of fibroblasts and endothelial cells to promote angiogenesis and tissue remodeling, resulting in faster wound healing.