Regulatory Mechanisms of the Wnt/β-Catenin Pathway in Diabetic Cutaneous Ulcers

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.

San Huang Xiao Yan recipe promoted wound healing in diabetic ulcer mice by inhibiting Th17 cell differentiation

ETHNOPHARMACOLOGICAL RELEVANCE

Diabetic ulcer is a serious diabetes complication and a primary reason for amputations. For many years, the San Huang Xiao Yan (SHXY) recipe has served as a conventional remedy for these ulcers, effectively reducing inflammatory factors and exhibiting considerable therapeutic efficacy. However, the precise mechanism remains incompletely understood.

AIM OF THE STUDY

To explore the efficacy and mechanisms of SHXY and its active ingredients in treating diabetic ulcer.

MATERIALS AND METHODS

A diabetic ulcer mouse model was established using C57BL/6J mice on a high-fat diet, followed by streptozotocin injection and skin damage. We investigated the bioactive compounds, key targets, and pharmacological mechanisms of SHXY in addressing diabetic ulcers through network pharmacology, molecular docking, both in vitro and in vivo validation experiments.

RESULTS

One week after intragastric administration, SHXY can reduce inflammation and edema, increase collagen synthesis, and reduce the expression of RORγT and IL-17A without affecting Treg cells. In vitro, SHXY-containing serum inhibited the differentiation of Th17 cells but did not affect Treg and Th1 cells. Network pharmacology found that SHXY acts through inflammatory pathways, including TNF, IL-17, Th17 cell differentiation, HIF-1, and PI3K-Akt.

CONCLUSIONS

SHXY and its candidate enhance healing in diabetic ulcers by modulating CD4+ T cells, particularly by inhibiting Th17 cell differentiation.

Exploring the potential mechanisms of the ethyl acetate fraction of Hippophae rhamnoides L. seeds as a natural healing agent for wound repair

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) has been designated a "medicine food homology" fruit by the National Health Commission of China due to its nutritional value. In traditional Chinese ethnomedicine, Hippophae rhamnoides L. is commonly used to treat nonhealing wounds such as burns, sores, and gastric ulcers. The aim of this study was to explore the healing effects of the ethyl acetate extract of sea buckthorn seeds (SBS-EF) on burn wounds.

AIM OF THE STUDY

The primary objectives of this research were to determine the most effective medicinal site of action for treating burns with sea buckthorn seeds (SBS) and to investigate the underlying material basis and mechanisms of their therapeutic effects.

MATERIALS AND METHODS

The effects of different components of SBS-EF on the proliferation and migration of human skin fibroblasts (HSFs) were evaluated via MTT assays, scratch assays, transwell assays, and hydroxyproline secretion analysis. SBS-EF displayed the greatest activity amongst the extracts. Subsequent analyses included network pharmacology methodology, molecular docking studies, ultraperformance liquid chromatography UPLC-Orbitrap-Exploris-120-MS and a severe second-degree burn rat model to investigate the chemical constituents and potential therapeutic mechanisms of the SBS-EF.

RESULTS

In vitro studies demonstrated the efficacy of SBS-EF in promoting HSF growth and migration. UPLC-Orbitrap-Exploris-120-MS analysis revealed that SBS-EF had ten major constituents, with flavonoids being the predominant compounds, especially catechin, quercetin, and kaempferol derivatives. Network pharmacology and molecular docking analyses indicated that SBS-EF may exert its healing effects by modulating the Wnt/β-catenin signalling pathway. Subsequent in vivo experiments demonstrated that SBS-EF accelerated burn wound healing in rats, increased hydroxyproline expression in skin tissue, facilitated skin structure repair, and enhanced collagen production and organisation over a 21 d period. Additionally, exposure to SBS-EF upregulated WNT3a and β-catenin while downregulating GSK-3β levels in rat skin tissue.

CONCLUSIONS

The wound healing properties of SBS-EF were attributed to its ability to enhance HSF growth and migration, increase hydroxyproline levels in the skin, promote collagen accumulation, reduce scarring, and decrease the skin water content. SBS-EF may also provide therapeutic benefits for burns by modulating the Wnt/β-catenin signalling pathway, as evidenced by its effective site and likely mechanism of action in the treatment of burned rats.

LRG1 Accelerates Wound Healing in Diabetic Rats by Promoting Angiogenesis via the Wnt/β-Catenin Signaling Pathway

Patients with diabetic wounds may end with lower extremity amputation or death. Leucine-rich α-2-glycoprotein 1 (LRG1) is an effective regulator of angiogenesis and essential for timely wound healing. However, its role in regulating angiogenesis in diabetic wounds remains unclear. This study aimed to investigate the pro-angiogenic function of exogenous LRG1 in diabetic wound healing and explore possible mechanisms. LRG1 expression patterns following injury in normal and diabetic wounds were determined by western blotting. Local injection of LRG1 was used to verify the effects on angiogenesis and wound healing in diabetic rats. Immunohistochemical staining for CD31 was used to analyze the vessel density. Human umbilical vein endothelial cells (HUVECs) cultured in hyperglycemia were used to explore how LRG1 promotes angiogenesis in diabetic wound healing. We found that the expression peak of LRG1 around the wounds was delayed in diabetic rats compared with that in normal rats. Exogenous administration of LRG1 significantly accelerated the wound closure rate and promoted angiogenesis in diabetic rats. In addition, exogenous LRG1 effectively restored the proliferation, migration, and tube formation ability of HUVECs under hyperglycemia. Mechanistically, LRG1 promoted angiogenesis and diabetic wound healing mainly by activating the Wnt/β-catenin pathway, which is inhibited in diabetic wounds. This research suggests that LRG1 promotes angiogenesis and wound closure in diabetic rats by improving angiogenesis via activation of the Wnt/β-catenin pathway. Hence, LRG1 may be a possible therapeutic strategy for diabetic foot treatment.

Emerging biomedical technologies for scarless wound healing

Complete wound healing without scar formation has attracted increasing attention, prompting the development of various strategies to address this challenge. In clinical settings, there is a growing preference for emerging biomedical technologies that effectively manage fibrosis following skin injury, as they provide high efficacy, cost-effectiveness, and minimal side effects compared to invasive and costly surgical techniques. This review gives an overview of the latest developments in advanced biomedical technologies for scarless wound management. We first introduce the wound healing process and key mechanisms involved in scar formation. Subsequently, we explore common strategies for wound treatment, including their fabrication methods, superior performance and the latest research developments in this field. We then shift our focus to emerging biomedical technologies for scarless wound healing, detailing the mechanism of action, unique properties, and advanced practical applications of various biomedical technology-based therapies, such as cell therapy, drug therapy, biomaterial therapy, and synergistic therapy. Finally, we critically assess the shortcomings and potential applications of these biomedical technologies and therapeutic methods in the realm of scar treatment.

Type 2 diabetes mellitus in adults: pathogenesis, prevention and therapy

Type 2 diabetes (T2D) is a disease characterized by heterogeneously progressive loss of islet β cell insulin secretion usually occurring after the presence of insulin resistance (IR) and it is one component of metabolic syndrome (MS), and we named it metabolic dysfunction syndrome (MDS). The pathogenesis of T2D is not fully understood, with IR and β cell dysfunction playing central roles in its pathophysiology. Dyslipidemia, hyperglycemia, along with other metabolic disorders, results in IR and/or islet β cell dysfunction via some shared pathways, such as inflammation, endoplasmic reticulum stress (ERS), oxidative stress, and ectopic lipid deposition. There is currently no cure for T2D, but it can be prevented or in remission by lifestyle intervention and/or some medication. If prevention fails, holistic and personalized management should be taken as soon as possible through timely detection and diagnosis, considering target organ protection, comorbidities, treatment goals, and other factors in reality. T2D is often accompanied by other components of MDS, such as preobesity/obesity, metabolic dysfunction associated steatotic liver disease, dyslipidemia, which usually occurs before it, and they are considered as the upstream diseases of T2D. It is more appropriate to call "diabetic complications" as "MDS-related target organ damage (TOD)", since their development involves not only hyperglycemia but also other metabolic disorders of MDS, promoting an up-to-date management philosophy. In this review, we aim to summarize the underlying mechanism, screening, diagnosis, prevention, and treatment of T2D, especially regarding the personalized selection of hypoglycemic agents and holistic management based on the concept of "MDS-related TOD".

A bioenergetically-active ploy (glycerol sebacate)-based multiblock hydrogel improved diabetic wound healing through revitalizing mitochondrial metabolism

Diabetic wounds impose significant burdens on patients' quality of life and healthcare resources due to impaired healing potential. Factors like hyperglycemia, oxidative stress, impaired angiogenesis and excessive inflammation contribute to the delayed healing trajectory. Mounting evidence indicates a close association between impaired mitochondrial function and diabetic complications, including chronic wounds. Mitochondria are critical for providing energy essential to wound healing processes. However, mitochondrial dysfunction exacerbates other pathological factors, creating detrimental cycles that hinder healing. This study conducted correlation analysis using clinical specimens, revealing a positive correlation between mitochondrial dysfunction and oxidative stress, inflammatory response and impaired angiogenesis in diabetic wounds. Restoring mitochondrial function becomes imperative for developing targeted therapies. Herein, we synthesized a biodegradable poly (glycerol sebacate)-based multiblock hydrogel, named poly (glycerol sebacate)-co-poly (ethylene glycol)-co-poly (propylene glycol) (PEPGS), which can be degraded in vivo to release glycerol, a crucial component in cellular metabolism, including mitochondrial respiration. We demonstrate the potential of PEPGS-based hydrogels to improve outcomes in diabetic wound healing by revitalizing mitochondrial metabolism. Furthermore, we investigate the underlying mechanism through proteomics analysis, unravelling the regulation of ATP and nicotinamide adenine dinucleotide metabolic processes, biosynthetic process and generation during mitochondrial metabolism. These findings highlight the therapeutic potential of PEPGS-based hydrogels as advanced wound dressings for diabetic wound healing.

Strictosamide promotes wound healing through activation of the PI3K/AKT pathway

Nauclea officinalis, as a Chinese medicine in Hainan province, had the effect of treating lower limb ulcers, burn infections. In this paper, we studied the effect of Strictosamide (STR), the main bioactive compound in Nauclea officinals, on wound healing and explored its internal mechanism. Firstly, the wound healing potential of STR was evaluated in a rat model, demonstrating its ability to expedite wound healing, mitigate inflammatory infiltration, and enhance collagen deposition. Additionally, immunofluorescence analysis revealed that STR up-regulated the expression of CD31 and PCNA. Subsequently, target prediction, protein-protein interaction (PPI), gene ontology (GO), and pathway enrichment analyses were used to obtain potential targets, specific biological processes, and molecular mechanisms of STR for the potential treatment of wound healing. Furthermore, molecular docking was conducted to predict the binding affinity between STR and its associated targets. Additionally, in vivo and in vitro experiments confirmed that STR could increase the expression of P-PI3K, P-AKT and P-mTOR by activating the PI3K/AKT signaling pathway. In summary, this study provided a new explanation for the mechanism by which STR promotes wound healing through network pharmacology, suggesting that STR may be a new candidate for treating wound.

Targeting Wnt/β-catenin signaling and its interplay with TGF-β and Notch signaling pathways for the treatment of chronic wounds

Wound healing is a tightly regulated process that ensures tissue repair and normal function following injury. It is modulated by activation of pathways such as the transforming growth factor-beta (TGF-β), Notch, and Wnt/β-catenin signaling pathways. Dysregulation of this process causes poor wound healing, which leads to tissue fibrosis and ulcerative wounds. The Wnt/β-catenin pathway is involved in all phases of wound healing, primarily in the proliferative phase for formation of granulation tissue. This review focuses on the role of the Wnt/β-catenin signaling pathway in wound healing, and its transcriptional regulation of target genes. The crosstalk between Wnt/β-catenin, Notch, and the TGF-β signaling pathways, as well as the deregulation of Wnt/β-catenin signaling in chronic wounds are also considered, with a special focus on diabetic ulcers. Lastly, we discuss current and prospective therapies for chronic wounds, with a primary focus on strategies that target the Wnt/β-catenin signaling pathway such as photobiomodulation for healing diabetic ulcers.

Revolutionizing Wound Healing: Exploring Scarless Solutions through Drug Delivery Innovations

Human skin is the largest organ and outermost surface of the human body, and due to the continuous exposure to various challenges, it is prone to develop injuries, customarily known as wounds. Although various tissue engineering strategies and bioactive wound matrices have been employed to speed up wound healing, scarring remains a significant challenge. The wound environment is harsh due to the presence of degradative enzymes and elevated pH levels, and the physiological processes involved in tissue regeneration operate on distinct time scales. Therefore, there is a need for effective drug delivery systems (DDSs) to address these issues. The objective of this review is to provide a comprehensive exposition of the mechanisms underlying the skin healing process, the factors and materials used in engineering DDSs, and the different DDSs used in wound care. Furthermore, this investigation will delve into the examination of emergent technologies and potential avenues for enhancing the efficacy of wound care devices.

Recent Advances of Chitosan-Based Hydrogels for Skin-Wound Dressings

The management of wound healing represents a significant clinical challenge due to the complicated processes involved. Chitosan has remarkable properties that effectively prevent certain microorganisms from entering the body and positively influence both red blood cell aggregation and platelet adhesion and aggregation in the bloodstream, resulting in a favorable hemostatic outcome. In recent years, chitosan-based hydrogels have been widely used as wound dressings due to their biodegradability, biocompatibility, safety, non-toxicity, bioadhesiveness, and soft texture resembling the extracellular matrix. This article first summarizes an overview of the main chemical modifications of chitosan for wound dressings and then reviews the desired properties of chitosan-based hydrogel dressings. The applications of chitosan-based hydrogels in wound healing, including burn wounds, surgical wounds, infected wounds, and diabetic wounds are then discussed. Finally, future prospects for chitosan-based hydrogels as wound dressings are discussed. It is anticipated that this review will form a basis for the development of a range of chitosan-based hydrogel dressings for clinical treatment.

The Role of p53 in Regulating Chronic Inflammation and PANoptosis in Diabetic Wounds

Diabetic wounds represent a formidable challenge in the clinical management of diabetes mellitus, markedly diminishing the patient's quality of life. These wounds arise from a multifaceted etiology, with the pathophysiological underpinnings remaining elusive and complex. Diabetes precipitates neuropathies and vasculopathies in the lower extremities, culminating in infections, ulcerations, and extensive tissue damage. The hallmarks of non-healing diabetic wounds include senescence, persistent inflammation, heightened apoptosis, and attenuated cellular proliferation. The TP53 gene, a pivotal tumor suppressor frequently silenced in human malignancies, orchestrates cellular proliferation, senescence, DNA repair, and apoptosis. While p53 is integral in cell cycle regulation, its role in initial tissue repair appears to be deleterious. In typical cutaneous wounds, p53 levels transiently dip, swiftly reverting to baseline. Yet in diabetic wounds, protracted p53 activation impedes healing via two distinct pathways: i) activating the p53-p21-Retinoblastoma (RB) axis, which halts the cell cycle, and ii) upregulating the cGAS-STING and nuclear factor-kappaB (NF-κB) cascades, instigating ferroptosis and pyroptosis. Furthermore, p53 intersects with various metabolic pathways, including glycolysis, gluconeogenesis, oxidative phosphorylation, and autophagy. In diabetic wounds, p53 may drive metabolic reprogramming, thus potentially derailing macrophage polarization. This review synthesizes case studies investigating the therapeutic modulation of p53 in diabetic wounds care. In summation, p53 modulates chronic inflammation and cellular aging within diabetic cutaneous wounds and is implicated in a novel cell death modality, encompassing ferroptosis and pyroptosis, which hinders the reparative process.

Diabetic peripheral neuropathy: pathogenetic mechanisms and treatment

Diabetic peripheral neuropathy (DPN) refers to the development of peripheral nerve dysfunction in patients with diabetes when other causes are excluded. Diabetic distal symmetric polyneuropathy (DSPN) is the most representative form of DPN. As one of the most common complications of diabetes, its prevalence increases with the duration of diabetes. 10-15% of newly diagnosed T2DM patients have DSPN, and the prevalence can exceed 50% in patients with diabetes for more than 10 years. Bilateral limb pain, numbness, and paresthesia are the most common clinical manifestations in patients with DPN, and in severe cases, foot ulcers can occur, even leading to amputation. The etiology and pathogenesis of diabetic neuropathy are not yet completely clarified, but hyperglycemia, disorders of lipid metabolism, and abnormalities in insulin signaling pathways are currently considered to be the initiating factors for a range of pathophysiological changes in DPN. In the presence of abnormal metabolic factors, the normal structure and function of the entire peripheral nervous system are disrupted, including myelinated and unmyelinated nerve axons, perikaryon, neurovascular, and glial cells. In addition, abnormalities in the insulin signaling pathway will inhibit neural axon repair and promote apoptosis of damaged cells. Here, we will discuss recent advances in the study of DPN mechanisms, including oxidative stress pathways, mechanisms of microvascular damage, mechanisms of damage to insulin receptor signaling pathways, and other potential mechanisms associated with neuroinflammation, mitochondrial dysfunction, and cellular oxidative damage. Identifying the contributions from each pathway to neuropathy and the associations between them may help us to further explore more targeted screening and treatment interventions.

A computational analysis to evaluate deleterious SNPs of GSK3β, a multifunctional and regulatory protein, for metabolism, wound healing, and migratory processes

This study focused on GSK-3β, a critical serine/threonine kinase with diverse cellular functions. However, there is limited understanding of the impact of non-synonymous single nucleotide polymorphisms (nsSNPs) on its structure and function. Through an exhaustive in-silico investigation 12 harmful nsSNPs were predicted from a pool of 172 acquired from the NCBI dbSNP database using 12 established tools that detects deleterious SNPs. Consistently, these nsSNPs were discovered in locations with high levels of conservation. Notably, the three harmful nsSNPs F67C, A83T, and T138I were situated in the active/binding site of GSK-3β, which may affect the protein's capacity to bind to substrates and other proteins. Molecular dynamics simulations revealed that the F67C and T138I mutants had stable structures, indicating rigidness, whereas the A83T mutant was unstable. Analysis of secondary structures revealed different modifications in all mutant forms, which may affect the stability, functioning, and interactions of the protein. These mutations appear to alter the structural dynamics of GSK-3β, which may have functional ramifications, such as the formation of novel secondary structures and variations in coil-to-helix transitions. In conclusion, this study illuminates the possible structural and functional ramifications of these GSK-3 nsSNPs, revealing how protein compactness, stiffness, and interactions may affect biological activities.

Microenvironmental dynamics of diabetic wounds and insights for hydrogel-based therapeutics

The rising prevalence of diabetes has underscored concerns surrounding diabetic wounds and their potential to induce disability. The intricate healing mechanisms of diabetic wounds are multifaceted, influenced by ambient microenvironment, including prolonged hyperglycemia, severe infection, inflammation, elevated levels of reactive oxygen species (ROS), ischemia, impaired vascularization, and altered wound physicochemical properties. In recent years, hydrogels have emerged as promising candidates for diabetic wound treatment owing to their exceptional biocompatibility and resemblance to the extracellular matrix (ECM) through a three-dimensional (3D) porous network. This review will first summarize the microenvironment alterations occurring in the diabetic wounds, aiming to provide a comprehensive understanding of its pathogenesis, then a comprehensive classification of recently developed hydrogels will be presented, encompassing properties such as hypoglycemic effects, anti-inflammatory capabilities, antibacterial attributes, ROS scavenging abilities, promotion of angiogenesis, pH responsiveness, and more. The primary objective is to offer a valuable reference for repairing diabetic wounds based on their unique microenvironment. Moreover, this paper outlines potential avenues for future advancements in hydrogel dressings to facilitate and expedite the healing process of diabetic wounds.

Molecular pathways of NF-ĸB and NLRP3 inflammasome as potential targets in the treatment of inflammation in diabetic wounds: A review

Diabetic wounds are slow healing wounds characterized by disordered healing processes and frequently take longer than three months to heal. One of the defining characteristics of impaired diabetic wound healing is an abnormal and unresolved inflammatory response, which is primarily brought on by abnormal macrophage innate immune signaling activation. The persistent inflammatory state in a diabetic wound may be attributed to inflammatory pathways such as nuclear factor kappa B (NF-ĸB) and nod-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, which have long been associated with inflammatory diseases. Despite the available treatments for diabetic foot ulcers (DFUs) that include debridement, growth factor therapy, and topical anti-bacterial agents, successful wound healing is still hampered. Further understanding of the molecular mechanism of these pathways could be useful in designing potential therapeutic targets for diabetic wound healing. This review provides an update and novel insights into the roles of NF-ĸB and NLRP3 pathways in the molecular mechanism of diabetic wound inflammation and their potential as therapeutic targets in diabetic wound healing.

Enzyme-Responsive Nanoparticles for Dexamethasone Targeted Delivery to Treat Inflammation in Diabetes

Diabetes is a global epidemic accompanied by impaired wound healing and increased risk of persistent infections and resistance to standard treatments. Therefore, there is an immense need to develop novel methods to specifically target therapeutics to affected tissues and improve treatment efficacy. This study aims to use enzyme-responsive nanoparticles for the targeted delivery of an anti-inflammatory drug, dexamethasone, to treat inflammation in diabetes. These nanoparticles are assembled from fluorescently-labeled, dexamethasone-loaded peptide-polymer amphiphiles. The nanoparticles are injected in vivo, adjacent to labeled collagen membranes sub-periosteally implanted on the calvaria of diabetic rats. Following their implantation, collagen membrane resorption is linked to inflammation, especially in hyperglycemic individuals. The nanoparticles show strong and prolonged accumulation in inflamed tissue after undergoing a morphological switch into microscale aggregates. Significantly higher remaining collagen membrane area and less inflammatory cell infiltration are observed in responsive nanoparticles-treated rats, compared to control groups injected with free dexamethasone and non-responsive nanoparticles. These factors indicate improved therapeutic efficacy in inflammation reduction. These results demonstrate the potential use of enzyme-responsive nanoparticles as targeted delivery vehicles for the treatment of diabetic and other inflammatory wounds.

Interaction of the AKT and β-catenin signalling pathways and the influence of photobiomodulation on cellular signalling proteins in diabetic wound healing

The induction of a cells destiny is a tightly controlled process that is regulated through communication between the matrix and cell signalling proteins. Cell signalling activates distinctive subsections of target genes, and different signalling pathways may be used repeatedly in different settings. A range of different signalling pathways are activated during the wound healing process, and dysregulated cellular signalling may lead to reduced cell function and the development of chronic wounds. Diabetic wounds are chronic and are characterised by the inability of skin cells to act in response to reparative inducements. Serine/threonine kinase, protein kinase B or AKT (PKB/AKT), is a central connection in cell signalling induced by growth factors, cytokines and other cellular inducements, and is one of the critical pathways that regulate cellular proliferation, survival, and quiescence. AKT interacts with a variety of other pathway proteins including glycogen synthase kinase 3 beta (GSK3β) and β-catenin. Novel methodologies based on comprehensive knowledge of activated signalling pathways and their interaction during normal or chronic wound healing can facilitate quicker and efficient diabetic wound healing. In this review, we focus on interaction of the AKT and β-catenin signalling pathways and the influence of photobiomodulation on cellular signalling proteins in diabetic wound healing.

Beta-Catenin Signaling Pathway: Perhaps We Should Start Exploring it for Diabetic Foot Ulcer Healing?

Diabetic foot ulcers (DFUs) remain a common debilitating and costly complication of diabetes mellitus. Indeed, despite all efforts and emerging technologies, many DFUs are difficult to heal and frequently recur. Thus, novel therapeutic approaches are urgently needed. Specific targeting of different molecular and cellular pathways implicated in wound healing emerges as an attractive therapeutic modality to improve outcomes. One of the novel pathways that carry this potential is the wingless-type mouse mammary tumor virus integration site family/beta-catenin signaling pathway (WβcSP). It plays an important role in different stages of wound healing, including inflammation, proliferation, and remodeling. Potential therapeutic implications of WβcSP activation include producing agonists and/or blocking its endogenous inhibitors. Thus, we should perhaps start exploring potential ways of its therapeutic implication to improve DFU healing.

Current status and progress in research on dressing management for diabetic foot ulcer

Diabetic foot ulcer (DFU) is a major complication of diabetes and is associated with a high risk of lower limb amputation and mortality. During their lifetime, 19%-34% of patients with diabetes can develop DFU. It is estimated that 61% of DFU become infected and 15% of those with DFU require amputation. Furthermore, developing a DFU increases the risk of mortality by 50%-68% at 5 years, higher than some cancers. Current standard management of DFU includes surgical debridement, the use of topical dressings and wound decompression, vascular assessment, and glycemic control. Among these methods, local treatment with dressings builds a protective physical barrier, maintains a moist environment, and drains the exudate from DFU wounds. This review summarizes the development, pathophysiology, and healing mechanisms of DFU. The latest research progress and the main application of dressings in laboratory and clinical stage are also summarized. The dressings discussed in this review include traditional dressings (gauze, oil yarn, traditional Chinese medicine, and others), basic dressings (hydrogel, hydrocolloid, sponge, foam, film agents, and others), bacteriostatic dressings, composite dressings (collagen, nanomaterials, chitosan dressings, and others), bioactive dressings (scaffold dressings with stem cells, decellularized wound matrix, autologous platelet enrichment plasma, and others), and dressings that use modern technology (3D bioprinting, photothermal effects, bioelectric dressings, microneedle dressings, smart bandages, orthopedic prosthetics and regenerative medicine). The dressing management challenges and limitations are also summarized. The purpose of this review is to help readers understand the pathogenesis and healing mechanism of DFU, help physicians select dressings correctly, provide an updated overview of the potential of biomaterials and devices and their application in DFU management, and provide ideas for further exploration and development of dressings. Proper use of dressings can promote DFU healing, reduce the cost of treating DFU, and reduce patient pain.

Mechanism of wound repair in diabetic rats using nanosilver-free alginate dressing

OBJECTIVE

Nanosilver-alginate dressing can effectively promote the healing of diabetic wounds in rats. However, due to the potential toxicity of nanosilver, its widespread application in hard-to-heal wound healing is limited. In the present study, the role and potential mechanism of nanosilver-free alginate gel (NSFAG) in the healing process of diabetic wounds were explored.

METHOD

A diabetic rat skin wound model was established, and wounds were treated with saline (NC group), nanosilver gel (NSG group) or nanosilver-free alginate gel (NSFAG group) for seven consecutive days.

RESULTS

NSFAG significantly promoted wound healing and increased the content of protein and hydroxyproline in granulation tissues, and was superior to NSG (p<0.05). Immunohistochemical analyses revealed that the skin wound tissue structure of the NSFAG group was intact, and the number of skin appendages in the dermis layer was significantly higher compared with the NC group and the NSG group (p<0.05). Western blot analysis found that the protein expression of the epidermal stem cell marker molecules CK19 and CK14 as well the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC group or NSG group (p<0.05). Additionally, the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC or NSG group (p<0.05). Immunofluorescence staining analyses indicated that the CK19- and CK14-positive cells were mainly distributed around the epidermis and the newly formed appendages in the NSFAG group, and this result was not observed in the NC or NSG groups.

CONCLUSION

The present findings demonstrate that NSFAG can effectively accelerate wound healing in diabetic rats by promoting epidermal stem cell proliferation and differentiation into skin cells, as well as formation of granulation tissue, suggesting that it can be a potential dressing for diabetic wounds.

Addition of Resolvins D1 or E1 to Collagen Membranes Mitigates Their Resorption in Diabetic Rats

Uncontrolled diabetes is characterized by aberrant inflammatory reactions and increased collagenolysis. We have reported that it accelerates the degradation of implanted collagen membranes (CM), thus compromising their function in regenerative procedures. In recent years, a group of physiological anti-inflammatory agents called specialized pro-resolving lipid mediators (SPMs) have been tested as a treatment for various inflammatory conditions, either systemically or locally, via medical devices. Yet, no study has tested their effect on the fate of the biodegradable material itself. Here, we measured the in vitro release over time of 100 or 800 ng resolvin D1 (RvD1) incorporated into CM discs. In vivo, diabetes was induced in rats with streptozotocin, while buffer-injected (normoglycemic) rats served as controls. Resolvins (100 or 800 ng of RvD1 or RvE1) were added to biotin-labeled CM discs, which were implanted sub-periosteally over the calvaria of rats. Membrane thickness, density, and uniformity were determined by quantitative histology after 3 weeks. In vitro, significant amounts of RvD1 were released over 1-8 days, depending on the amount loaded. In vivo, CMs from diabetic animals were thinner, more porous, and more variable in thickness and density. The addition of RvD1 or RvE1 improved their regularity, increased their density, and reduced their invasion by the host tissue significantly. We conclude that addition of resolvins to biodegradable medical devices can protect them from excessive degradation in systemic conditions characterized by high degree of collagenolysis.

In Vitro and In Silico Characterization of Curcumin-Loaded Chitosan-PVA Hydrogels: Antimicrobial and Potential Wound Healing Activity

Curcumin has been used in traditional medicine forages. The present study aimed to develop a curcumin-based hydrogel system and assess its antimicrobial potential and wound healing (WH) activity on an invitro and in silico basis. A topical hydrogel was prepared using chitosan, PVA, and Curcumin in varied ratios, and hydrogels were evaluated for physicochemical properties. The hydrogel showed antimicrobial activity against both gram-positive and gram-negative microorganisms. In silico studies showed good binding energy scores and significant interaction of curcumin components with key residues of inflammatory proteins that help in WH activity. Dissolution studies showed sustained release of curcumin. Overall, the results indicated wound healing potential of chitosan-PVA-curcumin hydrogel films. Further in vivo experiments are needed to evaluate the clinical efficacy of such films for wound healing.

Mechanisms of diabetic foot ulceration: A review

Diabetic foot ulcers (DFUs) are associated with complex pathogenic factors and are considered a serious complication of diabetes. The potential mechanisms underlying DFUs have been increasingly investigated. Previous studies have focused on the three aspects of diabetic peripheral vascular disease, neuropathy, and wound infections. With advances in technology, researchers have been gradually conducting studies using immune cells, endothelial cells, keratinocytes, and fibroblasts, as they are involved in wound healing. It has been reported that the upregulation or downregulation of molecular signaling pathways is essential for the healing of DFUs. With a recent increase in the awareness of epigenetics, its regulatory role in wound healing has become a much sought-after trend in the treatment of DFUs. This review focuses on four aspects involved in the pathogenesis of DFUs: physiological and pathological mechanisms, cellular mechanisms, molecular signaling pathway mechanisms, and epigenetics. Given the challenge in the treatment of DFUs, we are hopeful that our review will provide new ideas for peers.

Flavonoids as Potential Wound-Healing Molecules: Emphasis on Pathways Perspective

Wounds are considered to be a serious problem that affects the healthcare sector in many countries, primarily due to diabetes and obesity. Wounds become worse because of unhealthy lifestyles and habits. Wound healing is a complicated physiological process that is essential for restoring the epithelial barrier after an injury. Numerous studies have reported that flavonoids possess wound-healing properties due to their well-acclaimed anti-inflammatory, angiogenesis, re-epithelialization, and antioxidant effects. They have been shown to be able to act on the wound-healing process via expression of biomarkers respective to the pathways that mainly include Wnt/β-catenin, Hippo, Transforming Growth Factor-beta (TGF-β), Hedgehog, c-Jun N-Terminal Kinase (JNK), NF-E2-related factor 2/antioxidant responsive element (Nrf2/ARE), Nuclear Factor Kappa B (NF-κB), MAPK/ERK, Ras/Raf/MEK/ERK, phosphatidylinositol 3-kinase (PI3K)/Akt, Nitric oxide (NO) pathways, etc. Hence, we have compiled existing evidence on the manipulation of flavonoids towards achieving skin wound healing, together with current limitations and future perspectives in support of these polyphenolic compounds as safe wound-healing agents, in this review.

Mechanisms underlying pathological scarring by fibroblasts during wound healing

Pathological scarring is an abnormal outcome of wound healing, which often manifests as excessive proliferation and transdifferentiation of fibroblasts (FBs), and excessive deposition of the extracellular matrix. FBs are the most important effector cells involved in wound healing and scar formation. The factors that promote pathological scar formation often act on the proliferation and function of FB. In this study, we describe the factors that lead to abnormal FB formation in pathological scarring in terms of the microenvironment, signalling pathways, epigenetics, and autophagy. These findings suggest that understanding the causes of abnormal FB formation may aid in the development of precise and effective preventive and treatment strategies for pathological scarring that are associated with improved quality of life of patients.

Effect of Xanthii Fructus alcohol extract on proliferation and apoptosis of HFLS-RA and its mechanism

Xanthii fructus (XF) is the dried and mature fruit of Xanthium sibiricum Patr. It has the effects of anti-inflammatory, antioxidant and anti-arthritic. Rheumatoid arthritis (RA) is the most common inflammatory disorder and often leads to disability. However, there are few studies on the treatment of RA by XF and the specific mechanism of treatment has not been clarified. This study was designed to explore the effects of proliferation and apoptosis by XF on human fibroblast-like synovial-RA (HFLS-RA) cells and investigate its mechanism. The cell proliferation ability was detected by MTS assay. Hoechst 33,342 staining was used to detect apoptosis, and the apoptosis rate was detected by flow cytometry. The expression levels of NF-κB p65 and β-catenin were detected by Western Blotting. MTS, Hoechst 33,342, flow cytometry analysis showed that the alcohol extract of XF inhibited human fibroblast-like synovial-RA cells proliferation and promoted apoptosis in a dose-dependent manner. Western Blotting experiment showed that the extract of XF could reduce the expression levels of NF-κB p65 and β-catenin. The extract of XF has a significant therapeutic effect on RA in vitro by regulating NF-κB signaling pathway and Wnt/β-catenin signaling pathway. Our research will help to clarify the potential pharmacological mechanism of XF on RA and provide experimental basis for the application of XF in clinical treatment.

Macrophage polarization in diabetic wound healing

Impaired wound healing is one of the severe complications of diabetes. Macrophages have been shown to play a vital role in wound healing. In different wound environments, macrophages are classified into two phenotypes: classically activated macrophages and alternatively activated macrophages. Dysregulation of macrophage phenotypes leads to severely impaired wound healing in diabetes. Particularly, uncontrolled inflammation and abnormal macrophage phenotype are important reasons hindering the closure of diabetic wounds. This article reviews the functions of macrophages at various stages of wound healing, the relationship between macrophage phenotypic dysregulation and diabetic wound healing and the mechanism of macrophage polarization in diabetic wound healing. New therapeutic drugs targeting phagocyte polarization to promote the healing of diabetic wounds might provide a new strategy for treating chronic diabetic wound healing.

The uPA/uPAR system in astrocytic wound healing

The repair of injured tissue is a highly complex process that involves cell proliferation, differentiation, and migration. Cell migration requires the dismantling of intercellular contacts in the injured zone and their subsequent reconstitution in the wounded area. Urokinase-type plasminogen activator (uPA) is a serine proteinase found in multiple cell types including endothelial cells, smooth muscle cells, monocytes, and macrophages. A substantial body of experimental evidence with different cell types outside the central nervous system indicates that the binding of uPA to its receptor (uPAR) on the cell surface prompts cell migration by inducing plasmin-mediated degradation of the extracellular matrix. In contrast, although uPA and uPAR are abundantly found in astrocytes and uPA binding to uPAR triggers astrocytic activation, it is unknown if uPA also plays a role in astrocytic migration. Neuronal cadherin is a member of cell adhesion proteins pivotal for the formation of cell-cell contacts between astrocytes. More specifically, while the extracellular domain of neuronal cadherin interacts with the extracellular domain of neuronal cadherin in neighboring cells, its intracellular domain binds to β-catenin, which in turn links the complex to the actin cytoskeleton. Glycogen synthase kinase 3β is a serine-threonine kinase that prevents the cytoplasmic accumulation of β-catenin by inducing its phosphorylation at Ser33, Ser37, and Ser41, thus activating a sequence of events that lead to its proteasomal degradation. The data discussed in this perspective indicate that astrocytes release uPA following a mechanical injury, and that binding of this uPA to uPAR on the cell membrane induces the detachment of β-catenin from the intracellular domain of neuronal cadherin by triggering its extracellular signal-regulated kinase 1/2-mediated phosphorylation at Tyr650. Remarkably, this is followed by the cytoplasmic accumulation of β-catenin because uPA-induced extracellular signal-regulated kinase 1/2 activation also phosphorylates lipoprotein receptor-related protein 6 at Ser1490, which in turn, by recruiting glycogen synthase kinase 3β to its intracellular domain abrogates its effect on β-catenin. The cytoplasmic accumulation of β-catenin is followed by its nuclear translocation, where it induces the expression of uPAR, which is required for the migration of astrocytes from the injured edge into the wounded area.

The Signaling Pathways Induced by Exosomes in Promoting Diabetic Wound Healing: A Mini-Review

Impaired healing of diabetic wounds harms patients' quality of life and even leads to disability and death, which is an urgent issue to be solved clinically. Despite the great progress that has been achieved, it remains a worldwide challenge to develop effective therapeutic treatments for diabetic wounds. Recently, exosomes have attracted special attention because they can be involved in immune response, antigen presentation, cell migration, cell differentiation, tumor invasion and other processes. Meanwhile, exosomes have been proven to hold great potential in the treatment of diabetic wounds. Mechanistic studies of exosomes based on signaling pathways could not only help to uncover the mechanisms by which exosomes promote diabetic wound healing but could also provide a theoretical basis for the clinical application of exosomes. Herein, our mini-review aims to summarize the progress of research on the use of various exosomes derived from different cell types to promote diabetic wound healing, with a focus on the classical signaling pathways, including PI3K/Akt, Wnt, NF-κB, MAPK, Notch, Nrf2, HIF-1α/VEGF and TGF-β/Smad. The results show that exosomes could regulate these signaling pathways to down-regulate inflammation, reduce oxidative stress, increase angiogenesis, promote fibroblast proliferation, induce re-epithelization and inhibit scar formation, making exosomes attractive candidates for the treatment of diabetic wounds.

Tetrahedral framework nucleic acids promote diabetic wound healing via the Wnt signalling pathway

Objectives

To determine the therapeutic effect of tetrahedral framework nucleic acids (tFNAs) on diabetic wound healing and the underlying mechanism.

Materials and Methods

The tFNAs were characterized by polyacrylamide gel electrophoresis (PAGE), atomic force microscopy (AFM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential assays. Cell Counting Kit‐8 (CCK‐8) and migration assays were performed to evaluate the effects of tFNAs on cellular proliferation and migration. Quantitative polymerase chain reaction (Q‐PCR) and enzyme‐linked immunosorbent assay (ELISA) were used to detect the effect of tFNAs on growth factors. The function and role of tFNAs in diabetic wound healing were investigated using diabetic wound models, histological analyses and western blotting.

Results

Cellular proliferation and migration were enhanced after treatment with tFNAs in a high‐glucose environment. The expression of growth factors was also facilitated by tFNAs in vitro. During in vivo experiments, tFNAs accelerated the healing process in diabetic wounds and promoted the regeneration of the epidermis, capillaries and collagen. Moreover, tFNAs increased the secretion of growth factors and activated the Wnt pathway in diabetic wounds.

Conclusions

This study indicates that tFNAs can accelerate diabetic wound healing and have potential for the treatment of diabetic wounds.

Regulatory Processes of the Canonical Wnt/β-Catenin Pathway and Photobiomodulation in Diabetic Wound Repair

Skin is a biological system composed of different types of cells within a firmly structured extracellular matrix and is exposed to various external and internal insults that can break its configuration. The restoration of skin's anatomic continuity and function following injury is a multifaceted, dynamic, well-coordinated process that is highly dependent on signalling pathways, including the canonical Wnt/β catenin pathway, all aimed at restoring the skin's protective barrier. Compromised and inappropriate tissue restoration processes are often the source of wound chronicity. Diabetic patients have a high risk of developing major impediments including wound contamination and limb amputation due to chronic, non-healing wounds. Photobiomodulation (PBM) involves the application of low-powered light at specific wavelengths to influence different biological activities that incite and quicken tissue restoration. PBM has been shown to modulate cellular behaviour through a variety of signal transduction pathways, including the Wnt/β catenin pathway; however, the role of Wnt/β catenin in chronic wound healing in response to PBM has not been fully defined. This review largely focuses on the role of key signalling pathways in human skin wound repair, specifically, the canonical Wnt/β-catenin pathway, and the effects of PBM on chronic wound healing.

A combination of sugar esters and chitosan to promote in vivo wound care

In recent years, researchers are exploring innovative green materials fabricated from renewable natural substances to meet formulation needs. Among them, biopolymers like chitosans and biosurfactants such as sugar fatty acid esters are of potential interest due to their biocompatibility, biodegradability, functionality, and cost-effectiveness. Both classes of biocompounds possess the ability to be efficiently employed in wound dressing to help physiological wound healing, which is a bioprocess involving uncontrolled oxidative damage and inflammation, with an associated high risk of infection. In this work, we synthesized two different sugar esters (i.e., lactose linoleate and lactose linolenate) that, in combination with chitosan and sucrose laurate, were evaluated in vitro for their cytocompatibility, anti-inflammatory, antioxidant, and antibacterial activities and in vivo as wound care agents. Emphasis on Wnt/β-catenin associated machineries was also set. The newly designed lactose esters, sucrose ester, and chitosan possessed sole biological attributes, entailing considerable blending for convenient formulation of wound care products. In particular, the mixture composed of sucrose laurate (200 µM), lactose linoleate (100 µM), and chitosan (1%) assured its superiority in terms of efficient wound healing prospects in vivo together with the restoring of the Wnt/β-catenin signaling pathway, compared with the marketed wound healing product (Healosol®), and single components as well. This innovative combination of biomaterials applied as wound dressing could effectively break new ground in skin wound care.

TRIM24 promotes colorectal cancer cell progression via the Wnt/β-catenin signaling pathway activation

Overexpression of TRIM24 is observed in several human cancers and is correlated with an increase in the progression and metastasis of tumors. In this study, we investigated the changes in activity and biochemical events that occur after overexpression of TRIM24 in a colorectal cancer (CRC) mouse model. We observed upregulated TRIM24 expression in CRC tissues compared to that in nonneoplastic adjacent tissues. Enhanced expression of TRIM24 was significantly associated with the status of lymph nodes and poor recurrence-free survival of patients with CRC. The role of TRIM24 in CRC tumor growth was investigated using an orthotopic model of MC38 mouse colon cancer cells overexpressing TRIM24, and CRC tumor growth was found to increase dramatically by TRIM24 overexpression. Moreover, angiogenesis was stimulated by TRIM24 overexpression via the upregulation of vascular endothelial growth factor (VEGF) expression. Overexpression of TRIM24 in MC38 cells led to an increase in the protein levels of ALDH1 and other stem cell markers. In addition, we observed that Wnt/β-catenin signaling is required for the function of TRIM24 in CRC cells. Tumor-associated macrophages (TAMs) were found to be recruited by tumor cells overexpressing TRIM24 via the increased expression of CCL2/5, CSF-1, and VEGF, further enhancing CRC tumor growth. In conclusion, overexpression of TRIM24 facilitates the growth of CRC and the remodeling of the tumor stroma via angiogenesis stimulation and TAM recruitment. The Wnt/β-catenin pathway is a possible crucial link in the TRIM24-associated progression of tumors, which may provide opportunities for pharmacological intervention.

The Effect of Nanoparticle-Incorporated Natural-Based Biomaterials towards Cells on Activated Pathways: A Systematic Review

The advancement of natural-based biomaterials in providing a carrier has revealed a wide range of benefits in the biomedical sciences, particularly in wound healing, tissue engineering and regenerative medicine. Incorporating nanoparticles within polymer composites has been reported to enhance scaffolding performance, cellular interactions and their physico-chemical and biological properties in comparison to analogue composites without nanoparticles. This review summarized the current knowledge of nanoparticles incorporated into natural-based biomaterials with effects on their cellular interactions in wound healing. Although the mechanisms of wound healing and the function of specific cells in wound repair have been partially described, many of the underlying signaling pathways remain unknown. We also reviewed the current understanding and new insights into the wingless/integrated (Wnt)/β-catenin pathway and other signaling pathways of transforming growth factor beta (TGF-β), Notch, and Sonic hedgehog during wound healing. The findings demonstrated that most of the studies reported positive outcomes of biomaterial scaffolds incorporated with nanoparticles on cell attachment, viability, proliferation, and migration. Combining therapies consisting of nanoparticles and biomaterials could be promising for future therapies and better outcomes in tissue engineering and regenerative medicine.

The signaling pathways of traditional Chinese medicine in promoting diabetic wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

The diabetic wound is one of the common chronic complications of diabetes, which seriously affects patients' quality of life and even causes disability and death. Traditional Chinese medicine (TCM) is a unique and precious resource in China, which has a good curative effect and safety. At present, it has been found that Chinese herbal compounds and effective active ingredients can effectively promote diabetic wound healing, and its mechanism needs to be further studied. Signaling pathways are involved in the pathogenesis and progression of diabetic wounds, which is one of the main targets for the pathologic mechanism of diabetic wounds and the pharmacological research of therapeutic drugs.

AIM OF THE REVIEW

This study has been carried out to reveal the classical signaling pathways and potential targets by the action of TCM on diabetic wound healing and provides evidence for its clinical efficacy.

MATERIALS AND METHODS

"diabetic wound", "diabetic foot ulcer", "traditional Chinese medicine", "natural plant" and "medicinal plant", were selected as the main keywords, and various online search engines, such as PubMed, Web of Science, CNKI and other publication resources, were used for searching literature.

RESULTS

The results showed that TCM could regulate the signaling pathways to promote diabetic wound healing, such as Wnt, Nrf2/ARE, MAPK, PI3K/Akt, NF-κB, Notch, TGF-β/Smad, HIF-1α/VEGF, which maintaining inflammatory interaction balance, inhibiting oxidative stress and regulating abnormal glucose metabolism.

CONCLUSION

The effect of TCM on diabetic wound healing was reflected in multiple levels and multiple pathways. It is envisaged to carry out further research from precision-targeted therapy, provide ideas for screening the core target of TCM in treating diabetic wounds and create modern innovative drugs based on this target.

Pharmacological Effects of Centella asiatica on Skin Diseases: Evidence and Possible Mechanisms

The medicinal herb Centella asiatica (L.) Urban known as gotu kola has been reported to exhibit a wide range of pharmacological activities. In particular, a significant body of scientific research exists on the therapeutic properties of preparations of C. asiatica or its triterpenes in the treatment of skin diseases. The present study is aimed to provide a comprehensive overview of the beneficial effects of C. asiatica on skin diseases. Peer-reviewed articles on the potent dermatological effects of C. asiatica were acquired from PubMed, Web of Science, Scopus, ScienceDirect, and SciFinder. This review provides an understanding of pharmacological studies which confirm the potent dermatological effects and underlying molecular mechanisms of C. asiatica. This medicinal plant and its triterpenes include asiaticoside, madecassoside, and their aglycones, asiatic acid and madecassic acid. These compounds exert therapeutic effects on dermatological diseases such as acne, burns, atopic dermatitis, and wounds via NF-κB, TGF-β/Smad, MAPK, Wnt/β-catenin, and STAT signaling in in vitro and in vivo studies. However, additional rigorously controlled long-term clinical trials will be necessary to confirm the full potential of C. asiatica as a therapeutic agent.

Integrated analysis of tRNA-derived small RNAs reveals new therapeutic genes of hyperbaric oxygen in diabetic foot ulcers

Background: To reveal the alterations of tRNA-derived small RNA (tsRNA) expression profiles induced by hyperbaric oxygen (HBO) treatment in diabetic foot ulcers (DFUs) and investigate new therapeutic targets. Materials & methods: tsRNA sequencing was employed in normal skin tissue, in DFUs, and after HBO treatment groups. A quantitative real-time PCR was used to validate tsRNA sequencing results and their targets levels. Bioinformatics analysis was performed to reveal their therapeutic functions in DFUs. Results: A total of 22 tsRNAs were differentially expressed in the three groups. Three selected tsRNAs were validated by quantitative real-time PCR for further analysis, which were all significantly overexpressed in DFU while being normally expressed after HBO treatment. Bioinformatics analysis disclosed that these tsRNAs may play therapeutic roles through the regulation of the Wnt signaling pathway. Conclusion: tsRNAs may be novel useful targets for HBO to treat DFUs.

The Multiple Roles of Fibroblast Growth Factor in Diabetic Nephropathy

Diabetic nephropathy (DN) is a common microvascular complication in the late stages of diabetes. Currently, the etiology and pathogenesis of DN are not well understood. Even so, available evidence shows its development is associated with metabolism, oxidative stress, cytokine interaction, genetic factors, and renal microvascular disease. Diabetic nephropathy can lead to proteinuria, edema and hypertension, among other complications. In severe cases, it can cause life-threatening complications such as renal failure. Patients with type 1 diabetes, hypertension, high protein intake, and smokers have a higher risk of developing DN. Fibroblast growth factor (FGF) regulates several human processes essential for normal development. Even though FGF has been implicated in the pathological development of DN, the underlying mechanisms are not well understood. This review summarizes the role of FGF in the development of DN. Moreover, the association of FGF with metabolism, inflammation, oxidative stress and fibrosis in the context of DN is discussed. Findings of this review are expected to deepen our understanding of DN and generate ideas for developing effective prevention and treatments for the disease.

A Beginner's Introduction to Skin Stem Cells and Wound Healing

The primary function of the skin is that of a physical barrier against the environment and diverse pathogens; therefore, its integrity is essential for survival. Skin regeneration depends on multiple stem cell compartments within the epidermis, which, despite their different transcriptional and proliferative capacity, as well as different anatomical location, fall under the general term of skin stem cells (SSCs). Skin wounds can normally heal without problem; however, some diseases or extensive damage may delay or prevent healing. Non-healing wounds represent a serious and life-threatening scenario that may require advanced therapeutic strategies. In this regard, increased focus has been directed at SSCs and their role in wound healing, although emerging therapeutical approaches are considering the use of other stem cells instead, such as mesenchymal stem cells (MSCs). Given its extensive and broad nature, this review supplies newcomers with an introduction to SSCs, wound healing, and therapeutic strategies for skin regeneration, thus familiarizing the reader with the subject in preparation for future in depth reading.

In silico investigations on curcuminoids from Curcuma longa as positive regulators of the Wnt/β-catenin signaling pathway in wound healing

Background

Curcuma longa (Turmeric) is a traditionally used herb in wound healing. The efficacy of fresh turmeric paste to heal wounds has already been investigated in multiple ethnobotanical studies. Wnt/β-catenin signaling pathway plays a significant role in wound healing and injury repair processes which has been evident in different in vitro studies. This study aims to analyze the potentiality of curcuminoids (curcumin I, curcumin II and curcumin III) from Curcuma longa to bind and enhance the activity of two intracellular signaling proteins- casein kinase-1 (CK1) and glycogen synthase kinase-3β (GSK3B) involved in Wnt/β-catenin signaling pathway. This study is largely based on a computer-based molecular docking program which mimics the in vivo condition and works on a specific algorithm to interpret the binding affinity and poses of a ligand molecule to a receptor. Subsequently, drug likeness property, ADME/Toxicity profile, pharmacological activity, and site of metabolism of the curcuminoids were also analyzed.

Results

Curcumin I showed better affinity of binding with CK1 (− 10.31 Kcal/mol binding energy) and curcumin II showed better binding affinity (− 7.55 Kcal/mol binding energy) for GSK3B. All of the ligand molecules showed quite similar pharmacological properties.

Conclusion

Curcumin has anti-oxidant, anti-carcinogenic, anti-mutagenic, anti-coagulant, and anti-infective properties. Curcumin has also anti-inflammatory and wound healing properties. It hastens wound healing by acting on different stages of the natural wound healing process. In this study, three curcumins from Curcuma longa were utilized in this experiment in a search for a drug to be used in wound healing and injury repair processes. Hopefully, this study will raise research interest among researchers.

Bone marrow mesenchymal stem cells and their derived exosomes resolve doxorubicin-induced chemobrain: critical role of their miRNA cargo

Background

Doxorubicin (DOX), a widely used chemotherapeutic agent, can cause neurodegeneration in the brain, which leads to a condition known as chemobrain. In fact, chemobrain is a deteriorating condition which adversely affects the lives of cancer survivors. This study aimed to examine the potential therapeutic effects of bone marrow mesenchymal stem cells (BMSCs) and their derived exosomes (BMSCs-Exo) in DOX-induced chemobrain in rat models.

Methods

Chemobrain was induced by exposing rats to DOX (2 mg/kg, i.p) once weekly for 4 consecutive weeks. After 48 h of the last DOX dose, a subset of rats was supplied with either an intravenous injection of BMSCs (1 × 10⁶) or a single dose of 150 μg of BMSCs-Exo. Behavioral tests were conducted 7 days post injection. Rats were sacrificed after 14 days from BMSCs or BMSCs-Exo injection.

Results

BMSCs and BMSCs-Exo successfully restored DOX-induced cognitive and behavioral distortion. These actions were mediated via decreasing hippocampal neurodegeneration and neural demyelination through upregulating neural myelination factors (myelin%, Olig2, Opalin expression), neurotropic growth factors (BDNF, FGF-2), synaptic factors (synaptophysin), and fractalkine receptor expression (Cx3cr1). Halting neurodegeneration in DOX-induced chemobrain was achieved through epigenetic induction of key factors in Wnt/β-catenin and hedgehog signaling pathways mediated primarily by the most abundant secreted exosomal miRNAs (miR-21-5p, miR-125b-5p, miR-199a-3p, miR-24-3p, let-7a-5p). Moreover, BMSCs and BMSCs-Exo significantly abrogate the inflammatory state (IL-6, TNF-α), apoptotic state (BAX/Bcl2), astrocyte, and microglia activation (GFAP, IBA-1) in DOX-induced chemobrain with a significant increase in the antioxidant mediators (GSH, GPx, SOD activity).

Conclusions

BMSCs and their derived exosomes offer neuroprotection against DOX-induced chemobrain via genetic and epigenetic abrogation of hippocampal neurodegeneration through modulating Wnt/β-catenin and hedgehog signaling pathways and through reducing inflammatory, apoptotic, and oxidative stress state.

Graphical abstract

Proposed mechanisms of the protective effects of bone marrow stem cells (BMSCs) and their exosomes (BMSCs-Exo) in doxorubicin (DOX)-induced chemobrain. Blue arrows: induce. Red arrows: inhibit.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02384-9.

Jinmaitong ameliorates diabetes-induced peripheral neuropathy in rats through Wnt/β-catenin signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jinmaitong (JMT) is a prescription of Traditional Chinese Medicine, which is composed of ten herbal drugs and two animal drugs. It has long been used for the treatment of diabetic peripheral neuropathy (DPN).

AIM OF STUDY

Wnt/β-catenin pathway is considered as an essential and direct driver of myelinogenesis. This study aims to evaluate the protective effect of JMT against DPN dynamically during a 16-weeks' treatment, and to investigate the underlying mechanism in which the Wnt/β-catenin pathway is involved.

MATERIALS AND METHODS

Diabetic model was induced by single intraperitoneal injection of Streptozotocin (STZ) using male Sprague-Dawley rats. The model rats were divided into five groups and administrated with JMT at three doses (0.437, 0.875, and 1.75 g/kg per day), neurotropin (positive drug, 2.67 NU/kg per day), and placebo (deionized water), respectively, for continuous 8 weeks (n = 9-10), 12 weeks (n = 8-10), or 16 weeks (n = 7-9). Meanwhile, rats in control group were administrated with placebo (n = 10 for 8 weeks, n = 9 for 12 and 16 weeks, respectively). Blood glucose and body weight were monitored every four weeks. Mechanical allodynia was assessed using mechanical withdrawal threshold (MWT) test. The morphological change of sciatic nerves were observed by transmission electron microscope (TEM) and hematoxylin and eosin (HE) stain. The mRNA and protein levels of targeted genes were evaluated by quantitative real time-PCR and western bolt, respectively. Myelin protein zero (MPZ) and mediators involved in Wnt/β-catenin pathway, such as β-catenin, glycogen synthase kinase 3β (GSK-3β), and WNT inhibitory factor-1 (WIF-1), were compared among different groups after treatment of 8, 12, and 16 weeks, respectively.

RESULTS

The mechanical allodynia and peripheral nerve morphology were degenerated in DPN rats over time, and notably improved after JMT-treatment of 12 and 16 weeks. The decreased MPZ level in DPN rats were also significantly amended by JMT. More importantly, we found that the suppressed Wnt/β-catenin pathway in sciatic nerves of DPN rats was overtly up-regulated by JMT in a time-dependent manner. Among the three doses, JMT at the middle dose showed the best effect.

CONCLUSIONS

JMT effectively ameliorated diabetic-induced peripheral neuropathy, which was mediated by the activation of Wnt/β-catenin signaling pathway. This study provided new perspective to understand the neuroprotective mechanism of JMT.

An Integrative Pharmacology-Based Approach for Evaluating the Potential Effects of Purslane Seed in Diabetes Mellitus Treatment Using UHPLC-LTQ-Orbitrap and TCMIP V2.0

Portulaca oleracea L., known as the “vegetable for long life,” is an annual succulent herb that is widely distributed worldwide. Many clinical and experimental studies have demonstrated that purslane seed (MCXZ) can be used as an adjunctive and alternative therapy for the treatment of diabetes mellitus (DM). However, the underlying active constituents and pharmacological mechanisms through which MCXZ exerts effects in DM remain unclear. In the present study, we confirmed that MCXZ treatment resulted in hypoglycemic activity, lowering the fasting blood glucose and glycated hemoglobin levels in streptozotocin-induced diabetic mice. Then, ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry was used to systematically analyze the chemical profile of MCXZ, resulting in the identification of 84 constituents, including 31 organic acids and nine flavonoids. Finally, the Integrative Pharmacology-based Research Platform of Traditional Chinese Medicine was employed to analyze the key active components of MCXZ and the molecular mechanisms through which these components acted in DM. Ten key active compounds were identified based on the topological importance of their corresponding putative targets within the known DM-associated therapeutic target network of known MCXZ putative targets. Functionally, these candidate targets play critical anti-hyperlipidemia, anti-hyperglycemia, immunity regulation, and inflammatory roles involving DM-related pathways, such as the vascular endothelial growth factor (VEGF) signaling pathway and Fc gamma R-mediated phagocytosis, which indicated that MCXZ exhibited anti-diabetic activity through multi-faced actions.

Sustained release of inhibitor from bionic scaffolds for wound healing and functional regeneration

Small molecules play remarkable roles in promoting tissue regeneration, but are limited by their burst release. Small molecules such as deferoxamine (DFO) have been released slowly from silk hydrogels and stimulated angiogenesis and wound healing, but failed to achieve functional recovery of skin. Various bioactive molecules are required to create a suitable niche for better skin regeneration by controlling their release behaviors. Herein, a small molecule SB216763, a GSK-3 inhibitor, was loaded on silk fibroin nanofibers (SNF), and then mixed with chitosan (CS) to prepare the small molecule-loaded composite bionic scaffolds (CSNF-SB). Given the interaction of SNF and SB216763, the sustained release of SB216763 for more than 21 days was achieved for SNF and CSNF-SB composite scaffolds. Compared to drug-free CSNF scaffolds, CSNF-SB showed better cell adhesion and proliferation capacity, suggesting bioactivity. The upregulated expression of β-catenin in fibroblasts in vitro revealed that the released small molecules maintained their function in composite scaffolds. Quicker and better wound healing was realized with the drug-loaded scaffolds, which was significantly superior to that treated with drug-free scaffolds. Unlike the DFO-loaded silk hydrogel system, hair follicle neogenesis was also found in the drug-loaded-scaffold treatment wounds, demonstrating functional recovery. Therefore, silk nanofibers as versatile carriers for different small bioactive molecules could be used to fabricate scaffolds with optimized niches and then achieve functional recovery of tissues. The small molecule-loaded bionic scaffolds have a promising future in skin tissue regeneration.

Integrated analysis of circRNA-miRNA-mRNA regulatory network identifies potential diagnostic biomarkers in diabetic foot ulcer

Diabetic foot ulcer (DFU) is a common and serious complication of diabetes mellitus, which influences patients’ quality of life. Recently, circRNA regulated the mRNA levels by functioning as miRNA sponge in various disease, including diabetes mellitus. Nevertheless, the circRNA-miRNA-mRNA regulatory network involved in DFU remains obscure. The aim of this study is to construct a competing endogenous RNA (ceRNA) network and screen biological indicators as diagnostic factors in DFU.

All the differentially expressed circRNAs, miRNAs and mRNAs were derived from Gene Expression Omnibus database. Furthermore, circRNAs identified by cytoHubba analysis and miRNAs obtained by human miRNA-disease database were used to construct DFU-specific ceRNA network with intersection of mRNAs. Functional enrichment analysis displayed the function and pathway of dysregulated mRNAs. Hub genes with high diagnostic value were screened by ClusterONE, GO semantic similarity and receiver operating characteristic (ROC) curve.

Here, the ceRNA network consisted of 8 circRNAs, 11 miRNAs and 91 mRNAs. Functional enrichment analysis demonstrated diabetic complications-related pathway including TGF-beta, FoxO and Wnt signaling pathway. GO semantic similarity and ROC curve analysis showed 6 hub genes with high diagnostic value (the area under the ROC curve ≥ 0.8) in patients with DFU, including BCL2, CCND1, IRAK4, SMAD4, SP1 and SUFU, which were identified as potential target genes for DFU diagnosis. In conclusion, the present study looked at a circRNA-miRNA-mRNA regulatory network with DFU and screened the potential function of mRNA, then identified novel diagnostic biomarkers and therapeutic targets for patients with DFU.

Regulatory Mechanisms of lncRNAs and Their Target Gene Signaling Pathways in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a common malignant tumor that occurs in the head and neck. People living in areas with serious air pollution and those who smoke and drink for a long time belong to high-risk groups. Although great progress has been made in chemotherapy, radiotherapy, and molecular targeted therapy in recent years, the prognosis of patients is still not good. The proliferation, invasion, and apoptosis of LSCC are controlled by many factors, which are the key factors influencing the prognosis of patients. Previous researches have demonstrated that long noncoding RNAs (lncRNAs) can be used as oncogenes or tumor suppressor genes in the occurrence and development of cancer and regulate cancer through various ways including epigenetic regulation and post-transcriptional regulation. The characteristics and roles of lncRNAs in LSCC, however, are not clear. In this review, we will discuss the role and function of lncRNAs in the proliferation, invasion, and apoptosis of LSCC and analyze the relationship between lncRNAs and lncRNA-regulated signaling pathways in LSCC pathological process. The difficulties faced by the related research of LSCC are discussed. It provides reference ideas for the molecular mechanism research of LSCC targeting lncRNA and its signaling pathways, the development of clinical prevention and therapeutic drug and individualized treatment, thereby improving the quality of life of patients.

Accelerated degradation of collagen membranes in type 1 diabetic rats is associated with increased expression and production of several inflammatory molecules

BACKGROUND

Membrane durability is critical for regenerative procedures. We reported previously that type 1-like diabetes in rats accelerates the degradation of collagen membranes and we tested here whether this is associated with increased local production of inflammatory molecules as part of a diabetes-induced chronic inflammation around and within the membranes.

METHODS

Collagen membrane discs were implanted under the scalp in diabetic (streptozotocin-induced) and control rats, which were sacrificed after 2 or 3 weeks. Total RNA and proteins were isolated from the membrane and its surrounding tissues and the expression and production of six inflammatory molecules (interleukin-6 [IL-6], tumor necrosis factor alpha [TNFα], matrix metalloproteinase [MMP]-9, macrophage migration inhibitory factor [MIF], MIP-1α, and MIP-2α) was measured using real-time PCR and western blotting, respectively. Minimal histological analysis of the membranes was conducted to conform to previous studies.

RESULTS

Hyperglycemia resulted in reduced membrane thickness (by 10% to 25%) and increased mononuclear infiltrate inside the membrane. mRNA and protein levels of IL-6, TNFα, and MMP-9 were elevated in diabetic rats both 2 and 3 weeks post-surgery. The levels (both mRNA and protein) of MIF were increased at 2 weeks post-surgery and those of MIP-1α and MIP-2α at 3 weeks. There was a very good match in the temporal changes of all examined genes between the mRNA and protein levels.

CONCLUSIONS

Elevated local production of inflammatory cytokines and MMPs, together with apparent mononuclear infiltrate and increased collagenolysis confirm that hyperglycemia leads to a chronic inflammation in and around the implanted collagen membranes, which reduces membrane longevity.

Epidermal Stem Cells in Wound Healing and Regeneration

Skin stem cells distributed in the basal layer of the epidermis and hair follicles are important cell sources for skin development, metabolism, and injury repair. At present, great progress has been made in the study of epidermal stem cells at the cellular and molecular levels. Stem cell transplantation is reported to promote skin healing, endothelial cell transformation, and vascular formation. Local stem cells can also be transformed into keratinocytes, sebaceous gland, and other skin-associated tissues. However, the mechanism of action of epidermal stem cells on wound healing and regeneration is not completely clear. This review is aimed at briefly summarizing the biological characteristics of epidermal stem cells and their clinical application in wound healing and tissue regeneration. It further discussed the mechanism of action and the development direction in the future.

FoxO3a depletion accelerates cutaneous wound healing by regulating epithelial‑mesenchymal transition through β‑catenin activation

The hysteresis of keratinocyte (KC) re-epithelialization is an important factor resulting in chronic wounds; however, the molecular mechanisms involved in this cellular response remain yet to be completely elucidated. The present study demonstrated the function of transcription factor Forkhead box O3a (FoxO3a) in KC growth and migration functional effects, resulting in restrained KC re-epithelialization during wound healing. In chronic wound tissue samples, the expression of FoxO3a was significantly increased when compared with the acute wound healing group (P<0.01). Overexpressing FoxO3a significantly inhibited, whereas silencing endogenous FoxO3a enhanced, the growth and migration of HaCaT cells in vitro. Further investigation revealed that FoxO3a negatively regulated matrix metalloproteinases 1 and 9, and increased the expression of tissue inhibitor of metalloproteinase 1. In addition, the upregulation of FoxO3a retarded, whereas the downregulation of FoxO3a accelerated, transforming growth factor-β1-induced epithelial-mesenchymal transition in HaCaT cells. Mechanistically, the overexpression of FoxO3a inactivated β-catenin signaling and markedly reduced the levels of nuclear β-catenin. These results reveal a novel mechanism of FoxO3a in regulating KC re-epithelialization, and provide novel targets for the prevention and treatment of chronic wounds.