TAK1 activates PANoptosis through the NF-κB signalling pathway to delay diabetic wound healing

Topically applied opioids promote angiogenesis and healing of ischemic wounds in rats. We examined if topical fentanyl stimulates wound healing in diabetic rats by stimulating growth-promoting signaling, angiogenesis, lymphangiogenesis and nerve regeneration. We used Zucker diabetic fatty rats that develop obesity and diabetes on a high fat diet due to a mutation in the Leptin receptor. Fentanyl blended with hydrocream was applied topically on ischemic wounds twice daily, and wound closure was analyzed regularly. Wound histology was analyzed by hematoxylin and eosin staining. Angiogenesis, lymphangiogenesis, nerve fibers and phospho-platelet derived growth factor receptor-β (PDGFR-β) were visualized by CD31-, lymphatic vessel endothelium-1, protein gene product 9.5- and anti-phospho PDGFR-β-immunoreactivity, respectively. Nitric oxide synthase (NOS) and PDGFR-β signaling were analyzed using Western immunoblotting. Fentanyl significantly promoted wound closure as compared to phosphate-buffered saline (PBS). Histology scores were significantly higher in fentanyl-treated wounds, indicative of increased granulation tissue formation, reduced edema and inflammation, and increased matrix deposition. Fentanyl treatment resulted in increased wound angiogenesis, lymphatic vasculature, nerve fibers, nitric oxide, NOS and PDGFR-β signaling as compared to PBS. Phospho-PDGFR-β co-localized with CD31 co-staining for vasculature. Topically applied fentanyl promotes closure of ischemic wounds in diabetic rats. Increased angiogenesis, lymphangiogenesis, peripheral nerve regeneration, NO and PDGFR-β signaling are associated with fentanyl-induced tissue remodeling and wound healing.

A Zn-MOF-GOx-based cascade nanoreactor promotes diabetic infected wound healing by NO release and microenvironment regulation

Sustained ROS scavenging and pericellular oxygenation by lignin composites rescue HIF-1α and VEGF levels to improve diabetic wound neovascularization and healing.

Diabetic wounds remain a great challenge for clinicians due to the multiple bacterial infections and oxidative damage. Exosomes, as an appealing nanodrug delivery system, have been widely applied in the treatment of diabetic wounds. Endovascular cells are important component cells of the vascular wall. Herein, we investigated the effects of HUCMSCs and HUC-Exos (exosomes secreted by HUCMSCs) on diabetic wound healing. In this study, HUVECs were coincubated with HUCMSCs, and HUC-Exos were utilized for in vitro and in vivo experiments to verify their roles in the regulation of diabetic wound healing. Our results demonstrated that HUCMSCs have the ability to regulate oxidative stress injuries of endothelial cells through exosomes and accelerate diabetic cutaneous wound healing in vitro. The present study suggests that HUC-Exos accelerate diabetic cutaneous wound healing, providing a promising therapeutic strategy for chronic diabetic wound repair.

Angiogenesis and vasculogenesis: Inducing the growth of new blood vessels and wound healing by stimulation of bone marrow–derived progenitor cell mobilization and homing

BackgroundAdipose-derived stem cells (ADSCs) have been shown to accelerate diabetic wound healing by promoting neovascularization, though the underlying mechanisms are not fully understood. This study aims to explore whether ADSCs influence endothelial progenitor cells (EPCs) function to enhance diabetic wound healing.MethodsHuman adipose-derived stem cells (hADSCs) were isolated from patient adipose tissue and cultured under normal and high glucose (HG) conditions. RNA sequencing analyzed gene expression, while immunofluorescence validated findings in patient wound tissues. Mouse adipose-derived stem cells (ADSCs) from C57BL/6 mice were evaluated in vitro for their effects on EPCs under HG using EdU, Transwell, and tube formation assays. A diabetic mouse wound model was used to assess ADSCs therapeutic effects via digital imaging, histology, and immunofluorescence. Kruppel-like factor 5 (KLF5), identified via the JASPAR database, was confirmed by immunohistochemistry and immunofluorescence. KLF5 and C-X-C motif chemokine 12 (CXCL12) expression levels were measured by enzyme-linked immunosorbent assay (ELISA), western blot, and quantitative reverse transcription polymerase chain reaction (RT-qPCR), and their relationship was validated through dual-luciferase assays.ResultsWe constructed a neovascularization-related signature (NRS) comprising 75 genes on the basis of differentially expressed genes (DEGs) linked to neovascularization. GO and KEGG analyses revealed that the NRS is primarily involved in vasculature development and receptor–ligand activity. Seven hub genes (CD34, CXCL12, FGF7, FGF18, FGF1, TEK, KIT) were identified and validated. In a diabetic mouse model, CXCL12 knockdown in ADSCs reduced their ability of promoting wound healing and neovascularization. KLF5 expression was lower in patients with diabetic ulcers and diabetic mice wound tissues compared with normal tissues, while ADSCs treatment significantly increased KLF5 expression in diabetic mice wounds. Dual-luciferase reporter assays confirmed KLF5 as an upstream transcription factor of CXCL12. Additionally, knocking down KLF5 in ADSCs impaired their therapeutic effects on diabetic wound healing. In vitro, the addition of exogenous CXCL12 recombinant protein restored EPCs proliferation, migration, and vasculogenic capacity in a high glucose environment after KLF5 silencing in ADSCs.ConclusionsOur findings underscore the pivotal role of KLF5 in enhancing CXCL12 transcription within ADSCs, thereby facilitating EPC-mediated neovascularization and improving diabetic wound healing. Additionally, KLF5 emerges as a promising therapeutic target for accelerating tissue repair in diabetic wounds.Graphical

We have determined optimal laser dosimetric parameters in comparison with polychromatic light-emitting diodes (LEDs) that can speed up healing in four animal models: non-diabetic oval full-thickness wounds, diabetic oval full-thickness wounds, non-diabetic burns, and diabetic burns in Sprague-Dawley rats. This series of studies used 532-, 633-, 810-, 980-, and 10,600-nm lasers (visible to far infrared) and polychromatic LED clusters (510-872 nm, visible to infrared) as photon sources. Sprague-Dawley rats (n = 893) were used; however, animals that died before and during the experiments from anesthesia accidents and for any other reason were excluded from statistical analysis. The improvements seen (>10% improvement of impairment) show that phototherapy with the 633-nm laser is quite promising for alleviating diabetic wound and burn healing, and exhibited the best results with 38.5% and 53.4% improvements, respectively. In this induced-diabetes model, wound and burn healing were improved by 40.3% and 45%, respectively, in 633-nm laser dosimetry experiments, and diabetic wound and burn healing was accelerated by phototherapy. This indicates that the healing rate was normalized in the phototherapy-treated diabetic rats. In view of these interesting findings, 633-nm laser therapy given three times per week at 4.71 J/cm(2) per dose for diabetic burns, and three times per week at 2.35 J/cm(2) per dose for diabetic wound healing are recommended as actual doses for human clinical trials, especially after major surgery in those with impaired healing, such as diabetics and the elderly.

The chronic and refractory infected wounds of diabetes are primarily attributed to the persistent bacterial infection and the inhibition of wound healing caused by hypoxia. Hydrogel with intelligent drug delivery systems hold significant potential in the treatment of diabetic wounds. Herein, we have developed an glucose-responsive intelligent hydrogel named as CF-CPGaMPN, which incorporates polyvinylpyrrolidone-coated calcium peroxide (PVP@CaO2) nanoparticles, catalase, and gallium-polyphenol (GaMPN) nanoparticles. The borate ester bonds in the CF-CPGaMPN hydrogel break under high glucose conditions, releasing GaMPN nanoparticles, thereby achieving glucose-triggered on-demand drug release. The CF-CPGaMPN hydrogel not only inhibits various microorganisms but also continuously releases oxygen, thereby promoting the healing of diabetic infection wounds. Furthermore, the multicellular ecosystem surrounding the CF-CPGaMPN hydrogel is also explored, and the diverse cellular heterogeneity is analyzed by single-cell RNA sequencing, highlighting the critical roles of Neutrophils, Fibroblasts, and Epidermal cells in diabetic infected wound. In addition, CF-CPGaMPN hydrogel inhibits the Neutrophil extracellular trap (NET) formation and alleviates the cellular hypoxic environment to improve diabetic wound healing. In conclusion, the CF-CPGaMPN hydrogel not only provides a promising drug release strategy for the healing of diabetic infected wounds, but also contributes to the rational design of customized hydrogels for biomedical use targeting different cellular functions.

Objectives Diabetic wound inflammation deficiencies lead to ulcer development and eventual amputation and disability. Our previous research demonstrates that myeloid-derived suppressor cells (MDSCs) accumulate during inflammation and promote chronic wound healing via the regulation of Kruppel-like factor 4 (KLF4). In this study, we aimed to investigate the potential roles of MDSCs and KLF4 in diabetic wound healing. Methods An ob/ob mouse pressure ulcer (PU) model was used to evaluate the process of wound healing. The expression levels of KLF4 and IL-17A were measured by real-time PCR, and the population of MDSCs and Th17 cells was measured by flow cytometry. The levels of cytokines were determined by an immunosuppression assay. Results KLF4 deficiency in the diabetic PU model resulted in decreased accumulation of MDSCs, increased expansion of Th17 cells, and significantly delayed wound healing. Conversely, KLF4 activation by APTO-253 accelerated wound healing accompanied by increased MDSC populations and decreased numbers of Th17 cells. MDSCs have been proven to mediate Th17 differentiation via cytokines, and our in vitro data showed that elevated KLF4 expression in MDSCs resulted in reduced Th17 cell numbers and, thus, decreased levels of cytokines indispensable for Th17 differentiation. Conclusions Our study revealed a previously unreported function of KLF4-regulated MDSCs in diabetic wound healing and identified APTO-253 as a potential agent to improve the healing of pressure ulcers.

Significantly effective therapies need to be developed for chronic nonhealing diabetic wounds. In this work, the topical transplantation of mesenchymal stem cell (MSC) seeded on an acellular dermal matrix (ADM) scaffold is proposed as a novel therapeutic strategy for diabetic cutaneous wound healing. GFP-labeled MSCs were cocultured with an ADM scaffold that was decellularized from normal mouse skin. These cultures were subsequently transplanted as a whole into the full-thickness cutaneous wound site in streptozotocin-induced diabetic mice. Wounds treated with MSC-ADM demonstrated an increased percentage of wound closure. The treatment of MSC-ADM also greatly increased angiogenesis and rapidly completed the reepithelialization of newly formed skin on diabetic mice. More importantly, multiphoton microscopy was used for the intravital and dynamic monitoring of collagen type I (Col-I) fibers synthesis via second harmonic generation imaging. The synthesis of Col-I fibers during diabetic wound healing is of great significance for revealing wound repair mechanisms. In addition, the activity of GFP-labeled MSCs during wound healing was simultaneously traced via two-photon excitation fluorescence imaging. Our research offers a novel advanced nonlinear optical imaging method for monitoring the diabetic wound healing process while the ADM and MSCs interact in situ. Schematic of dynamic imaging of ADM scaffolds seeded with mesenchymal stem cells in diabetic wound healing using multiphoton microscopy. PMT, photo-multiplier tube.

Objective: Impaired wound healing in diabetic (DB) patients is a significant health problem; however, the roles that cytokines and innate immune cells contribute to this impaired healing are not completely understood. Approach: A mouse model was used to compare the innate immune response during DB and normal wound healing. Two 5-mm full-thickness wounds were created on the dorsal skin of BKS.Cg-m+/+Leprdb/J (DB) and C57BL/6 (wild-type) mice. Innate immune cell markers and cytokine mRNA levels were measured in wound biopsies during the first week of healing. Results: Innate immune cell influx (typified by the Gr-1 neutrophil marker and the Ym1 macrophage marker) was delayed in the DB wounds. Expression of the M2 macrophage-related genes, Ym1 and arginase 1, was significantly reduced in the DB wounds. PCR array analysis demonstrated altered cytokine expression in DB wounds. Most prominently, both interleukin (IL)-17 and IL-20 mRNA levels were significantly increased in the DB wounds. Innovation: This is the first study to identify increased levels of IL-17 and IL-20 in DB wounds. These cytokines are also elevated in the inflammatory skin disorder, psoriasis; thus, they may be potential therapeutic targets to aid in DB wound healing. Conclusion: The entire cytokine profile of DB wounds over the course of healing is not completely understood. This study suggests that the IL-17 and IL-20 families of cytokines should be further analyzed in the context of DB wound healing.

BackgroundChronic nonhealing wounds are major complications in diabetic patients, with impaired angiogenesis playing a critical role in the delayed healing process. Current treatments for diabetic wounds are inadequate. The dysregulation of endothelial cell genes, particularly thrombospondin-1 (TSP-1), impairs neovascularization and delays wound repair. In recent years, hydrogel-based wound dressings have gained widespread application in biomedicine. The study introduced a new therapeutic approach, embedding miR-221-3p-loaded small extracellular vesicles (miR-221OE-sEVs) within gelatin methacryloyl (GelMA) hydrogels to reduce TSP-1 levels and improve healing in diabetic wounds.MethodsFirst, we observed upregulated TSP-1 expression in human umbilical vein endothelial cells (HUVECs) when cultured in a high-glucose (HG) environment. We employed small interfering RNA (siRNA) and miR-221-3p to suppress TSP-1 expression and then evaluate the functional effects on HUVECs. Subsequently, miR-221-3p was encapsulated in sEVs via lentiviral transfection. The effects of miR-221OE-sEVs on HUVECs under HG conditions were evaluated. Finally, miR-221OE-sEVs were incorporated into a GelMA hydrogel (G-miR-221OE-sEVs) and applied to a diabetic murine wound model to evaluate their effects on wound closure and angiogenesis.ResultsUnder HG conditions, the use of siTSP-1 to silence TSP-1 enhanced the proliferation, migration, and tube formation capabilities of HUVECs. Similarly, miR-221-3p treatment exerted proregenerative effects via the targeting of TSP-1. We successfully generated miR-221OE-sEVs that exhibited a 28-fold increase in miR-221-3p expression, which significantly enhanced HUVEC functionality under HG conditions. Encapsulation within the GelMA hydrogel enabled G-miR-221OE-sEVs to significantly accelerate diabetic wound healing via increased angiogenesis.ConclusionsThis study demonstrated the successful fabrication of a novel bioactive wound dressing (G-miR-221OE-sEVs), which promotes diabetic wound healing by promoting angiogenesis through the regulation of TSP-1. This approach offers a potential therapeutic option for enhancing the management of diabetic wounds.

Background Circulating micro-RNAs are differentially expressed in various tissues and could be considered as potential regulatory biomarkers for T2DM and related complications, such as chronic wounds. Aim In the current study, we investigated whether ginger extract enriched with [6]-gingerol-fractions either alone or in combination with vitamin D accelerates diabetic wound healing and explores underlying molecular changes in the expression of miRNA and their predicted role in diabetic wound healing. Methods Diabetic wounded mice were treated with [6]-gingerol-fractions (GF) (25 mg/kg of body weight) either alone or in combination with vitamin D (100 ng/kg per day) for two weeks. Circulating miRNA profile, fibrogenesis markers, hydroxyproline (HPX), fibronectin (FN), and collagen deposition, diabetic control variables, FBS, HbA1c, C-peptide, and insulin, and wound closure rate and histomorphometric analyses were, respectively, measured at days 3, 6, 9, and 15 by RT–PCR and immunoassay analysis. Results Treatment of diabetic wounds with GF and vitamin D showed significant improvement in wound healing as measured by higher expression levels of HPX, FN, collagen, accelerated wound closure, complete epithelialization, and scar formation in short periods (11-13 days, (P < 0.01). On a molecular level, three circulating miRNAs, miR-155, miR-146a, and miR-15a, were identified in diabetic and nondiabetic skin wounds by PCR analysis. Lower expression in miR-155 levels and higher expression of miR-146a and miR-15a levels were observed in diabetic skin wounds following treatment with gingerols fractions and vitamin D for 15 days. The data showed that miRNAs, miR-146a, miR-155, and miR-15a, correlated positively with the expression levels of HPX, FN, and collagen and negatively with FBS, HbA1c, C-peptide, and insulin in diabetic wounds following treatment with GF and /or vitamin D, respectively. Conclusion Treatment with gingerols fractions (GF) and vitamin D for two weeks significantly improves delayed diabetic wound healing. The data showed that vitamin D and gingerol activate vascularization, fibrin deposition (HPX, FN, and collagen), and myofibroblasts in such manner to synthesize new tissues and help in the scar formation. Accordingly, three miRNAs, miR-155, miR-146a, and miR-15, as molecular targets, were identified and significantly evaluated in wound healing process. It showed significant association with fibrin deposition, vascularization, and reepithelialization process following treatment with GF and vitamin D. It proposed having anti-inflammatory action and promoting new tissue formation via vascularization process during the wound healing. Therefore, it is very interesting to consider miRNAs as molecular targets for evaluating the efficiency of nondrug therapy in the regulation of wound healing process.

Diabetic chronic wounds and amputations are very serious complications of diabetes mellitus (DM) that result from an integration factor, including oxygen deprivation, elevated reactive oxygen species (ROS), reduced angiogenesis, and microbial invasion. These causative factors lead to tenacious wounds in an inflammatory state, which eventually results in tissue aging and necrosis. Wound healing in DM potentially targets C-X-C chemokine receptor type 4 (CXCR4) regulates several signalling pathways. The CXCR4 signalling pathway integrated with phospholipase C (PLC)/protein kinase-C (PKC) Ca2+ pathways, stromal cell-derived factor-1 (SDF-1), and mitogen- activated protein kinases (MAPKs) pathway for enhancing cell chemotaxis, proliferation, and survival. The dysregulated CXCR4 pathway is connected with poor wound healing in DM patients. Therapeutic strategies targeting CXCR4-based molecules such as UCUF-728, UCUF-965, and AMD3100 have been shown to enhance diabetic wound healing by altering miRNA expression, promoting angiogenesis, and accelerating wound closure. This study indicates that CXCR4 participation in various signalling pathways makes it essential for understanding the healing of diabetic wounds. Using specific compounds to target CXCR4 offers a potentially effective treatment strategy to improve wound healing in diabetes. Our understanding of CXCR4 signalling and its regulation processes will enable us to develop more potent wound care solutions for diabetic chronic wounds. This report concludes that CXCR4's potential therapeutic targeting shows improvements in diabetic wound repair. This review will demonstrate that CXCR4 plays a major role in wound healing through its various signalling pathways. Targeting CXCR4 with certain agonist molecules shows a therapeutic approach to potentially increasing wound healing in diabetes. By enhancing our understanding of the CXCR4 signalling mechanism in future studies, we can develop more potential treatments for chronic diabetic wounds.

Vascular deficits are a fundamental contributing factor of diabetes-associated diseases. Although previous studies have demonstrated that the pro-angiogenic phase of wound healing is blunted in diabetes, a comprehensive understanding of the mechanisms that regulate skin revascularization and capillary stabilization in diabetic wounds is lacking. Using a mouse model of diabetic wound healing, we performed microCT analysis of the 3-dimensional architecture of the capillary bed. As compared to wild type, vessel surface area, branch junction number, total vessel length, and total branch number were significantly decreased in wounds of diabetic mice as compared to WT mice. Diabetic mouse wounds also had significantly increased capillary permeability and decreased pericyte coverage of capillaries. Diabetic wounds exhibited significant perturbations in the expression of factors that affect vascular regrowth, maturation and stability. Specifically, the expression of VEGF-A, Sprouty2, PEDF, LRP6, Thrombospondin 1, CXCL10, CXCR3, PDGFR-β, HB-EGF, EGFR, TGF-β1, Semaphorin3a, Neuropilin 1, angiopoietin 2, NG2, and RGS5 were down-regulated in diabetic wounds. Together, these studies provide novel information about the complexity of the perturbation of angiogenesis in diabetic wounds. Targeting factors responsible for wound resolution and vascular pruning, as well those that affect pericyte recruitment, maturation, and stability may have the potential to improve diabetic skin wound healing.