Single cell transcriptomic landscape of diabetic foot ulcers

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

A glucose responsive multifunctional hydrogel with antibacterial properties and real-time monitoring for diabetic wound treatment

The healing of complex diabetic wounds with a hyperglycemic microenvironment and bacterial infection is considered an important clinical issue. In this study, glucose oxidase (GOx) and gold nanoclusters (AuNCs) were encapsulated in quaternary carboxymethyl chitosan (QCMCS)/sodium alginate oxide (OSA) hydrogels and were immersed in tannic acid (TA) solution to achieve antioxidant, antibacterial, pro-angiogenesis, pro-collagen deposition and real-time monitoring functions. In vitro studies showed that TA-QCMCS/OSA@GOx@AuNC hydrogels had inhibition rates of 98.99% and 99.99% against S. aureus and E. coli, respectively, and the survival rate of mouse fibroblasts (L929) was over 95%. In vivo studies showed that TA-QCMCS/OSA@GOx@AuNC hydrogels were 97.28% effective in healing diabetic wounds. In addition, image signals from TA-QCMCS/OSA@GOx@AuNC hydrogels can be collected in real time to accurately obtain glucose concentration values of diabetic wounds and reflect the healing status of diabetic wounds in a timely manner. The results showed that TA-QCMCS/OSA@GOx@AuNC hydrogels provide a novel idea for real-time monitoring of diabetic wound treatment.

Bioprinted Symbiotic Dressings: A Lichen-Inspired Approach to Diabetic Wound Healing with Enhanced Bioactivity and Structural Integrity

Providing oxygen and preventing infection at wound sites are effective ways to heal diabetic chronic wounds. Inspired by natural lichens, a bioprinted biogenic hydrogel (BBH) containing microalgae and probiotics is developed for diabetic chronic wound therapeutics, which offers prolonged biogenetic oxygen supply by microalgae and infection inhibition by probiotics. The rational design of symbiotic BBH with customizable structure and microorganism composition enhances wound resilience against elevated glucose levels and hypoxia, leading to the increased migration ability of fibroblasts and the angiogenic potential of human umbilical vein endothelial cells. Notably, BBH-treated diabetic wounds exhibit dense vascular distribution, reduced hypoxia levels and inflammatory responses, and enhanced epithelial differentiation and keratinization abilities. Consequently, the BBH achieves rapid tissue repairing within 3 d and restores approximately 90% of the whole skin structure within 12 d. This work presents an engineered platform for regulating biological microenvironment of diabetic wounds and provides insights for developing bioprinted hybrid microorganism systems.

MCC950 promotes diabetic wound healing through modulating macrophage polarization in an MDSC-dependent manner

Diabetic foot ulcers (DFUs) are serious skin injuries whereby the wound healing process is frequently stalled in the inflammatory phase. Currently, there is a lack of effective therapeutic strategies. MCC950, a highly selective nod-like receptor family pyrin domain containing 3 (NLRP3) inhibitor, has been reported to show strong anti-inflammation effects in many diseases. In this study, we unveiled the role of MCC950 in DFU mice model and its underlying molecular mechanisms. MCC950 could significantly accelerate diabetic wound healing, as shown by shortened healing time and better healing quality. Moreover, increased M2 phenotype macrophages and decreased pro-inflammatory genes were observed in MCC950-treated DFU mice. Additionally, myeloid-derived suppressor cells (MDSCs) were significantly increased in blood, spleen and wound tissues at different time courses. Specifically, MCC950 could recruit more MDSCs in an early phase in DFU mice, exerting an anti-inflammation effect. We identified the cell crosstalk between macrophages and MDSCs with MCC950 treatment process. Depleting MDSCs in vivo could eliminate the therapeutic effect of MCC950 on diabetic wound healing through inhibiting M2 macrophage polarization. Besides, MDSCs isolated from the wounds of MCC950 or saline treated mice were cocultured with bone marrow derived macrophage (BMDM) in a transwell system. Results confirmed that MDSCs sorted from MCC950 treated mice caused a significant increased percentage of M2 macrophages. Collectively, our findings suggest that the administration of MCC950 has the potential to accelerate diabetic wound healing by promoting M2 macrophage polarization in an MDSC-dependent manner. This study provides valuable insights into the utilization of pharmacological agents for DFU treatment.

PANoptosis signaling enables broad immune response in psoriasis: From pathogenesis to new therapeutic strategies

BACKGROUND

Accumulating evidence suggests that regulated cell death, such as pyroptosis, apoptosis, and necroptosis, is deeply involved in the pathogenesis of psoriasis. As a newly recognized form of systematic cell death, PANoptosis is involved in a variety of inflammatory disorders through amplifying inflammatory and immune cascades, but its role in psoriasis remains elusive.

OBJECTIVES

To reveal the role of PANoptosis in psoriasis for a potential therapeutic strategy.

METHODS

Multitranscriptomic analysis and experimental validation were used to identify PANoptosis signaling in psoriasis. RNA-seq and scRNA-seq analyses were performed to establish a PANoptosis-mediated immune response in psoriasis, which revealed hub genes through WGCNA and predicted disulfiram as a potential drug. The effect and mechanism of disulfiram were verified in imiquimod (IMQ)-induced psoriasis.

RESULTS

Here, we found a highlighted PANoptosis signature in psoriasis patients through multitranscriptomic analysis and experimental validation. Based on this, two distinct PANoptosis patterns (non/high) were identified, which were the options for clinical classification. The high-PANoptosis-related group had a higher response rate to immune cell infiltration (such as M1 macrophages and keratinocytes). Subsequently, WGCNA showed the hub genes (e.g., S100A12, CYCS, NOD2, STAT1, HSPA4, AIM2, MAPK7), which were significantly associated with clinical phenotype, PANoptosis signature, and identified immune response in psoriasis. Finally, we explored disulfiram (DSF) as a candidate drug for psoriasis through network pharmacology, which ameliorated IMQ-mediated psoriatic symptoms through antipyroptosis-mediated inflammation and enhanced apoptotic progression. By analyzing the specific ligand-receptor interaction pairs within and between cell lineages, we speculated that DSF might exert its effects by targeting keratinocytes directly or targeting M1 macrophages to downregulate the proliferation of keratinocytes.

CONCLUSIONS

PANoptosis with its mediated immune cell infiltration provides a roadmap for research on the pathogenesis and therapeutic strategies of psoriasis.

Schlafen5, regulated by the AP-1 family transcription factor c-Fos, affects diabetic wound healing through modulating PI3K/Akt/NRF2 axis

Diabetic ulcers (DUs) present significant physical and psychological challenges to patients, while placing a significant economic burden on healthcare systems. Promoting the blood vessel regeneration is critical for ensuring the delivery of essential nutrients and oxygen to the injured area, thereby supporting the healing process. To gain insight into the complex molecular mechanisms that drive DUs healing, we performed a comprehensive analysis of single-cell transcriptomic data from healing and non-healing DU states. This analysis revealed a key role of Schlafen5 (SLFN5) signal in modulating key healing processes. SLFN5, a protein known to regulate cellular processes like migration, invasion, inflammation, and cell death, emerged as an important player. Yet, although it is prominent, the specific function of SLFN5 in diabetic skin wounds remained unclear. Our study discovered a marked elevation of SLFN5 levels in endothelial cells within DUs and its suppression notably mitigates the oxidative stress and endoplasmic reticulum stress (ERS)-mediated cell death pathways, including pyroptosis and apoptosis. This finding implies that excessive SLFN5 activity might obstruct wound closure by intensifying cellular stress reactions. Upon further investigation, we found that the antioxidant and cytoprotective effects were mediated through enhanced NRF2 activity, facilitated by the PI3K/Akt signaling pathway. Moreover, our investigation identified that c-Fos as a pivotal transcription factor governing SLFN5 transcription during the development of DUs, offering valuable insights into the regulation of SLFN5 expression. In diabetic mice model, SLFN5 knockdown accelerating wound healing, which was intervened by PI3K/Akt inhibitor. These results hold significant therapeutic potential, indicating that targeting SLFN5 may represent a novel and effective strategy for improving wound healing outcomes in patients with DUs.

Assessment of potential genetic markers for diabetic foot ulcer among Moscow residents

PURPOSE

Diabetic foot ulcer (DFU) is one of the most severe complications of type 2 diabetes, which is manifested in chronic skin ulcers of lower extremities. DFU treatment remains complex and expensive despite the availability of well-established protocols. Early prediction of potential DFU development at the onset of type 2 diabetes can greatly improve the aftermath of this complication.

METHODS

To assess potential genetic markers for DFU, a group of diabetic patients from Moscow region with and without DFU was genotyped for a number of SNPs previously reported to be associated with the DFU.

RESULTS

Obtained results did not confirm previously claimed association of rs1024611, rs3918242, rs2073618, rs1800629, rs4986790, rs179998, rs1963645 and rs11549465 (respectively, in MCP1, MMP9, TNFRSF11B, TNFα, TLR4, eNOS, NOS1AP and HIF1α genes) with the DFU. Surprisingly, the t allele of rs7903146 in the TCF7l2 gene known as one of the most prominent risk factors for type 2 diabetes has shown a protective effect on DFU with OR(95%) = 0.68(0.48-0.96).

CONCLUSION

Non-replication of previously published SNP associations with DFU suggests that the role of genetic factors in the DFU onset is either highly variable in different populations or is not as significant as the role of non-genetic factors.

Chitosan-Based Hydrogels as Antibacterial/Antioxidant/Anti-Inflammation Multifunctional Dressings for Chronic Wound Healing

Due to repeated microbial infection, persistent inflammation, excessive oxidative stress, and cell dysfunction, chronic wounds are difficult to heal, posing a serious threat to public health. Therefore, developing multifunctional wound dressings that can regulate the complex microenvironment of chronic wounds and enhance cellular function holds great significance. Recently, chitosan has emerged as a promising biopolymer for wound healing due to its excellent biocompatibility, biodegradability, and versatile bioactivity. The aim of this review is to provide a comprehensive understanding of the mechanisms of delayed chronic wound healing and discuss the healing-promoting properties of chitosan and its derivatives, such as good biocompatibility, antibacterial activity, hemostatic capacity, and the ability to promote tissue regeneration. On this basis, the potential applications of chitosan-based hydrogels are summarized in chronic wound healing, including providing a suitable microenvironment, eliminating bacterial infections, promoting hemostasis, inhibiting chronic inflammation, alleviating oxidative stress, and promoting tissue regeneration. In addition, the concerns and perspectives for the clinical application of chitosan-based hydrogels are also discussed.

Immunomodulatory Hydrogel for Electrostatically Capturing Pro-inflammatory Factors and Chemically Scavenging Reactive Oxygen Species in Chronic Diabetic Wound Remodeling

Diabetic wound exhibits the complex characteristics involving continuous oxidative stress and excessive expression of pro-inflammatory cytokines to cause a long-term inflammatory microenvironment. The repair healing of chronic diabetic wounding is tremendously hindered due to persistent inflammatory reaction. To address the aforementioned issues, here, a dual-functional hydrogel is designed, consisting of N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1, N1, N3, N3-tetramethylpropane-1, 3-diaminium (TSPBA) modified polyvinyl alcohol (PVA) and methacrylamide carboxymethyl chitosan (CMCSMA) can not only electrostatically adsorb proinflammatory cytokines of IL1-β and TNF-α, but can also chemically scavenge the excessive reactive oxygen species (ROS) in situ. Both in vitro and in vivo evaluations verify that the negatively charged and ROS-responsive hydrogel (NCRH) can effectively modulate the chronic inflammatory microenvironment of diabetic wounds and significantly enhance wound remodeling. More importantly, the well-designed NCRH shows a superior skin recovery in comparison with the commercial competitor product of wound dressing. Consequently, the current work highlights the need for new strategies to expedite the healing process of diabetic wounds and offers a wound dressing material with immunomodulation.

Recent advances in coaxial electrospun nanofibers for wound healing

The skin is the body's primary immune barrier, defending it against pathogenic invasion. Skin injuries impose a significant physiological burden on patients, making effective wound management essential. Dressings are commonly employed in wound care, and electrospun nanofiber dressings are a research hotspot owing to their ease of fabrication, cost-effectiveness, and structural similarity to the extracellular matrix. Coaxial electrospinning offers considerable advantages in drug delivery, fiber structure transformation, and enhanced interaction with the host. These attributes make coaxial electrospun materials promising candidates for precision and personalized wound dressings in medical treatments. This review provides a comprehensive overview of wound healing and its influencing factors. It also outlines coaxial electrospinning's production principles and benefits in wound dressings. Guided by the factors affecting wound healing, coaxial electrospun nanofiber dressings have different application modalities. Furthermore, we discuss the current limitations and future directions for enhancing the current coaxial electrospun dressing technologies.

Bulk and Single-Cell Transcriptome Analyses Unravel Gene Signatures of Mitochondria-Associated Programmed Cell Death in Diabetic Foot Ulcer

Mitochondrial programmed cell death (PCD) plays a critical role in the pathogenesis of diabetic foot ulcers (DFU). In this study, we performed a comprehensive transcriptome analysis to identify potential hub genes and key cell types associated with PCD and mitochondria in DFU. Using intersection analysis of PCD- and mitochondria-related genes, we identified candidate hub genes through protein-protein interaction and random forest analysis. At the single-cell level, key cell types were further validated based on the expression of hub genes. Additionally, we explored the transcription factors (TFs) regulating hub gene expression and the cellular heterogeneity of DFU. Finally, the expression of key hub genes and TFs was validated in clinical specimens. Our results identified BCL2 and LIPT1 as significantly downregulated hub genes in DFU, with Keratinocytes, as the key cell type. Immunohistochemistry confirmed downregulation of BCL2 and LIPT1 in DFU samples (p < 0.05). Additionally, TFs CEBPD and IRF1 were significantly upregulated in DFU, as confirmed by real-time polymerase chain reaction analysis (p < 0.05).

SDC4 protein action and related key genes in nonhealing diabetic foot ulcers based on bioinformatics analysis and machine learning

Diabetic foot ulcers (DFU) is a complication associated with diabetes characterised by high morbidity, disability, and mortality, involving chronic inflammation and infiltration of multiple immune cells. We aimed to identify the critical genes in nonhealing DFU using single-cell RNA sequencing, transcriptomic analysis and machine learning. The GSE165816, GSE134431, and GSE143735 datasets were downloaded from the GEO database. We processed and screened the datasets, and identified the cell subsets. Each cell subtype was annotated, and the predominant cell types contributing to the disease were analysed. Key genes were identified using the LASSO regression algorithm, followed by verification of model accuracy and stability. We investigated the molecular mechanisms and changes in signalling pathways associated with this disease using immunoinfiltration analysis, GSEA, and GSVA. Through scRNA-seq analysis, we identified 12 distinct cell clusters and determined that the basalKera cell type was important in disease development. A high accuracy and stability prediction model was constructed incorporating five key genes (TXN, PHLDA2, RPLP1, MT1G, and SDC4). Among these five genes, SDC4 has the strongest correlation and plays an important role in the development of DFU. Our study identified SDC4 significantly associated with nonhealing DFU development, potentially serving as new prevention and treatment strategies for DFU.

Fibroblast-Mediated Macrophage Recruitment Supports Acute Wound Healing

Epithelial and immune cells have long been appreciated for their contribution to the early immune response after injury; however, much less is known about the role of mesenchymal cells. Using single-nuclei RNA sequencing, we defined changes in gene expression associated with inflammation 1 day after wounding in mouse skin. Compared with those in keratinocytes and myeloid cells, we detected enriched expression of proinflammatory genes in fibroblasts associated with deeper layers of the skin. In particular, SCA1+ fibroblasts were enriched for numerous chemokines, including CCL2, CCL7, and IL-33, compared with SCA1- fibroblasts. Genetic deletion of Ccl2 in fibroblasts resulted in fewer wound-bed macrophages and monocytes during injury-induced inflammation, with reduced revascularization and re-epithelialization during the proliferation phase of healing. These findings highlight the important contribution of fibroblast-derived factors to injury-induced inflammation and the impact of immune cell dysregulation on subsequent tissue repair.

Endothelial-to-mesenchymal transition in the tumor microenvironment: Roles of transforming growth factor-β and matrix metalloproteins

Cancer is a leading cause of global morbidity and mortality. Tumor cells grow in a complex microenvironment, comprising immune cells, stromal cells, and vascular cells, collaborating to support tumor growth and facilitate metastasis. Transforming growth factor-beta (TGF-β) is a multipotent factor that can not only affect fibrosis promotion but also assume distinct roles in the early and late stages of the tumor. Matrix metalloproteinases (MMPs) primarily function to degrade the extracellular matrix, a pivotal cellular player in tumor progression. Moreover, endothelial-to-mesenchymal transition (EndMT), similar to epithelial-to-mesenchymal transition, is associated with cancer progression by promoting angiogenesis, disrupting the endothelial barrier, and leading to cancer-associated fibroblasts. Recent studies have underscored the pivotal roles of TGF-β and MMPs in EndMT. This review delves into the contributions of TGF-β and MMPs, as well as their regulatory mechanisms, within the tumor microenvironment. This collective understanding offers fresh insights into the potential for combined targeted therapies in the fight against cancer.

Characterizing Fibroblast Heterogeneity in Diabetic Wounds Through Single-Cell RNA-Sequencing

Diabetes mellitus is an increasingly prevalent chronic metabolic disorder characterized by physiologic hyperglycemia that, when left uncontrolled, can lead to significant complications in multiple organs. Diabetic wounds are common in the general population, yet the underlying mechanism of impaired healing in such wounds remains unclear. Single-cell RNA-sequencing (scRNAseq) has recently emerged as a tool to study the gene expression of heterogeneous cell populations in skin wounds. Herein, we review the history of scRNAseq and its application to the study of diabetic wound healing, focusing on how innovations in single-cell sequencing have transformed strategies for fibroblast analysis. We summarize recent research on the role of fibroblasts in diabetic wound healing and describe the functional and cellular heterogeneity of skin fibroblasts. Moreover, we highlight future opportunities in diabetic wound fibroblast research, with a focus on characterizing distinct fibroblast subpopulations and their lineages. Leveraging single-cell technologies to explore fibroblast heterogeneity and the complex biology of diabetic wounds may reveal new therapeutic targets for improving wound healing and ultimately alleviate the clinical burden of chronic wounds.

Multi-drug resistant Staphylococcus epidermidis from chronic wounds impair healing in human wound model

Venous leg ulcers (VLUs) represent one of the most prevalent types of chronic wounds characterised by perturbed microbiome and biofilm-forming bacteria. As one of the most abundant skin-commensal, Staphylococcus epidermidis is known as beneficial for the host, however, some strains can form biofilms and hinder wound healing. In this study, S. epidermidis distribution in VLUs and associated resistome were analysed in ulcer tissue from patients. Virulence of S. epidermidis isolates from VLUs were evaluated by whole genome sequencing, antimicrobial susceptibility testing, in vitro biofilm and binding assays, and assessment of biofilm-forming capability and pro-inflammatory potential using human ex vivo wound model. We demonstrated that S. epidermidis isolates from VLUs inhibit re-epithelialization through biofilm-dependent induction of IL-1β, IL-8, and IL-6 which was in accordance with impaired healing outcomes observed in patients. High extracellular matrix binding ability of VLU isolates was associated with antimicrobial resistance and expression levels of the embp and sdrG, responsible for bacterial binding to fibrinogen and fibrin, respectively. Finally, we showed that S. epidermidis from VLUs demonstrate pathogenic features with ability to impair healing which underscores the emergence of treatment-resistant virulent lineages in patients with chronic ulcers.

Engineered Enucleated Mesenchymal Stem Cells Regulating Immune Microenvironment and Promoting Wound Healing

Persistent excessive inflammation caused by neutrophil and macrophage dysfunction in the wound bed leads to refractory response during wound healing. However, previous studies using cytokines or drugs often suffer from short half-lives and limited targeting, resulting in unsatisfactory therapeutic effects. Herein, the enucleated mesenchymal stem cell is engineered by aptamer bioorthogonal chemistry to modify the cell membrane and mRNA loading in the cell cytoplasm as a novel delivery vector (Cargocyte) with accurate targeting and sustained cytokine secretion. Cargocytes can successfully reduce NETosis by targeting the nuclear chromatin protein DEK protein with aptamers and sustaining interleukin (IL)-4 expression to overcome the challenges associated with the high cost and short half-life of IL-4 protein and significantly prevent the transition of macrophages into the M1 phenotype. Therapeutic effects have been demonstrated in murine and porcine wound models and have powerful potential to improve wound immune microenvironments effectively. Overall, the use of engineered enucleated mesenchymal stem cells as a delivery system may be a promising approach for wound healing.

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

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

Differences in cell subsets between sun-exposed and unexposed skin: preliminary single-cell sequencing and biological analysis from a single case

Introduction

The composition and subsets of skin cells continuously change in a dynamic manner. However, the specific microcosmic alterations of human photoaged skin, independent of chronologic aging, remain unclear and have been infrequently analyzed. This study aimed to evaluate the biological processes and mechanisms underlying cell-subgroup alterations in skin photoaging.

Methods

We utilized single-cell sequencing and biological analysis from a single case to investigate the effects of photoaging. Skin punch biopsies were taken from sun-exposed forearm skin and unexposed buttock skin from the same individual for comparative analysis.

Results

Our analysis identified 25 cell clusters and 12 skin cell types, revealing significant changes in unique gene expressions between the sun-exposed and unexposed skin samples. A comparison of cell numbers within each cluster revealed 9 dominant cell clusters in sun-exposed skin and 16 dominant cell clusters in unexposed skin. Enrichment analysis indicated that PD-L1 expression and the PD-1 checkpoint pathway were more prominent in sun-exposed skin, while MAPK, TNF-alpha, TGF-beta, and apoptosis pathways were more enriched in hair follicle cells of sun-exposed skin.

Discussion

This study reveals changes in cell components in photoaged skin from a single case and provides novel insights into cellular subpopulations and pathology during repeated UVA-induced skin damage. These findings enhance our understanding of the complex interplay between different cells in photoaged skin and offer potential targets for preventing human skin photoaging and UV-induced skin cancers.

Transcriptome-wide Mendelian randomization during CD4+ T cell activation reveals immune-related drug targets for cardiometabolic diseases

Immunity has shown potentials in informing drug development for cardiometabolic diseases, such as type 2 diabetes (T2D) and coronary artery disease (CAD). Here, we performed a transcriptome-wide Mendelian randomization (MR) study to estimate the putative causal effects of 11,021 gene expression profiles during CD4+ T cells activation on the development of T2D and CAD. Robust MR and colocalization evidence was observed for 162 genes altering T2D risk and 80 genes altering CAD risk, with 12% and 16% respectively demonstrating CD4+ T cell specificity. We observed temporal causal patterns during T cell activation in 69 gene-T2D pairs and 34 gene-CAD pairs. These genes were eight times more likely to show robust genetic evidence. We further identified 25 genes that were targets for drugs under clinical investigation, including LIPA and GCK. This study provides evidence to support immune-to-metabolic disease connections, and prioritises immune-mediated drug targets for cardiometabolic diseases.

Single-cell sequencing technology in skin wound healing

Skin wound healing is a complicated biological process that mainly occurs in response to injury, burns, or diabetic ulcers. It can also be triggered by other conditions such as dermatitis and melanoma-induced skin cancer. Delayed healing or non-healing after skin injury presents an important clinical issue; therefore, further explorations into the occurrence and development of wound healing at the cellular and molecular levels are necessary. Single-cell sequencing (SCS) is used to sequence and analyze the genetic messages of a single cell. Furthermore, SCS can accurately detect cell expression and gene sequences. The use of SCS technology has resulted in the emergence of new concepts pertaining to wound healing, making it an important tool for studying the relevant mechanisms and developing treatment strategies. This article discusses the application value of SCS technology, the effects of the latest research on skin wound healing, and the value of SCS technology in clinical applications. Using SCS to determine potential biomarkers for wound repair will serve to accelerate wound healing, reduce scar formation, optimize drug delivery, and facilitate personalized treatments.

A hydrogen generator composed of poly (lactic-co-glycolic acid) nanofibre membrane loaded iron nanoparticles for infectious diabetic wound repair

Diabetic wound, which is chronic skin disease, poses a significant challenge in clinical practice because of persistent inflammation and impaired angiogenesis. Recently, hydrogen has emerged as a novel therapeutic agent due to its superior antioxidant and anti-inflammatory properties. In this study, we engineered a poly (lactic-co-glycolic acid) (PLGA) electrospun nanofibre membrane loaded with citric acid (CA) and iron (Fe) nanoparticles, referred to as Fe@PLGA + CA. Our in vitro assays demonstrated that the Fe@PLGA + CA membrane continuously generated and released hydrogen molecules via a chemical reaction between Fe and CA in an acidic microenvironment created by CA. We also discovered that hydrogen can ameliorate fibroblast migration disorders by reducing the levels of matrix metalloproteinase 9 (MMP9). Furthermore, we confirmed that hydrogen can scavenge or biochemically neutralise accumulated reactive oxygen species (ROS), inhibit pro-inflammatory responses, and induce anti-inflammatory reactions. This, in turn, promotes vessel formation, wound-healing and accelerates skin regeneration. These findings open new possibilities for using elemental iron in skin dressings and bring us one step closer to implementing hydrogen-releasing biomedical materials in clinical practice.

Mechanisms of HIF1A-mediated immune evasion in gastric cancer and the impact on therapy resistance

BACKGROUND

The high prevalence and detrimental effects on patient outcomes make gastric cancer (GC) a significant health issue that persists internationally. Existing treatment modalities exhibit limited efficacy, prompting the exploration of immune checkpoint inhibitors as a novel therapeutic approach. However, resistance to immunotherapy poses a significant challenge in GC management, necessitating a profound grasp of the intrinsic molecular pathways.

METHODS

This study focuses on investigating the immunosuppressive mechanisms of quiescent cancer cells (QCCs) in GC, particularly their resistance to T-cell-mediated immune responses. Utilizing mouse models, gene editing techniques, and transcriptome sequencing, we aim to elucidate the interactions between QCCs, immune cells, and key regulatory factors like HIF1A. Functional enrichment analysis will further underscore the role of glycolysis-related genes in mediating immunosuppression by QCCs.

RESULTS

The cancer cells that survived GC treated with T-cell therapy lost their proliferative ability. QCCs, as the main resistance force to immunotherapy, exhibit stronger resistance to CD8+ T-cell attack and possess higher cancer-initiating potential. Single-cell sequencing analysis revealed that the microenvironment in the QCCs region harbors more M2-type tumor-associated macrophages and fewer T cells. This microenvironment in the QCCs region leads to the downregulation of T-cell immune activation and alters macrophage metabolic function. Transcriptome sequencing of QCCs identified upregulated genes related to chemo-resistance, hypoxia, and glycolysis. In vitro cell experiments illustrated that HIF1A promotes the transcription of glycolysis-related genes, and silencing HIF1A in QCCs enhances T-cell proliferation and activation in co-culture systems, induces apoptosis in QCCs, and increases QCCs' sensitivity to immune checkpoint inhibitors. In vivo, animal experiments showed that silencing HIF1A in QCCs can inhibit GC growth and metastasis.

CONCLUSION

Unraveling the molecular mechanisms by which QCCs resist T-cell-mediated immune responses through immunosuppression holds promising implications for refining treatment strategies and enhancing patient outcomes in GC. By delineating these intricate interactions, this study contributes crucial insights into precision medicine and improved therapeutic outcomes in GC management.

Multimodal Identification of Molecular Factors Linked to Severe Diabetic Foot Ulcers Using Artificial Intelligence

Diabetic foot ulcers (DFUs) are a severe complication of diabetes mellitus (DM), which often lead to hospitalization and non-traumatic amputations in the United States. Diabetes prevalence estimates in South Texas exceed the national estimate and the number of diagnosed cases is higher among Hispanic adults compared to their non-Hispanic white counterparts. San Antonio, a predominantly Hispanic city, reports significantly higher annual rates of diabetic amputations compared to Texas. The late identification of severe foot ulcers minimizes the likelihood of reducing amputation risk. The aim of this study was to identify molecular factors related to the severity of DFUs by leveraging a multimodal approach. We first utilized electronic health records (EHRs) from two large demographic groups, encompassing thousands of patients, to identify blood tests such as cholesterol, blood sugar, and specific protein tests that are significantly associated with severe DFUs. Next, we translated the protein components from these blood tests into their ribonucleic acid (RNA) counterparts and analyzed them using public bulk and single-cell RNA sequencing datasets. Using these data, we applied a machine learning pipeline to uncover cell-type-specific and molecular factors associated with varying degrees of DFU severity. Our results showed that several blood test results, such as the Albumin/Creatinine Ratio (ACR) and cholesterol and coagulation tissue factor levels, correlated with DFU severity across key demographic groups. These tests exhibited varying degrees of significance based on demographic differences. Using bulk RNA-Sequenced (RNA-Seq) data, we found that apolipoprotein E (APOE) protein, a component of lipoproteins that are responsible for cholesterol transport and metabolism, is linked to DFU severity. Furthermore, the single-cell RNA-Seq (scRNA-seq) analysis revealed a cluster of cells identified as keratinocytes that showed overexpression of APOE in severe DFU cases. Overall, this study demonstrates how integrating extensive EHRs data with single-cell transcriptomics can refine the search for molecular markers and identify cell-type-specific and molecular factors associated with DFU severity while considering key demographic differences.

Liraglutide Promotes Diabetic Wound Healing via Myo1c/Dock5

Non-healing diabetic wounds and ulcer complications, with persistent cell dysfunction and obstructed cellular processes, are leading causes of disability and death in patients with diabetes. Currently, there is a lack of guideline-recommended hypoglycemic drugs in clinical practice, likely due to limited research and unclear mechanisms. In this study, it is demonstrated that liraglutide significantly accelerates wound closure in diabetic mouse models (db/db mice and streptozotocin-induced mice) by improving re-epithelialization, collagen deposition, and extracellular matrix remodeling, and enhancing the proliferation, migration, and adhesion functions of keratinocytes. However, these effects of improved healing by liraglutide are abrogated in dedicator of cytokinesis 5 (Dock5) keratinocyte-specific knockout mice. Mechanistically, liraglutide induces cellular function through stabilization of unconventional myosin 1c (Myo1c). Liraglutide directly binds to Myo1c at arginine 93, enhancing the Myo1c/Dock5 interaction by targeting Dock5 promoter and thus promoting the proliferation, migration, and adhesion of keratinocytes. Therefore, this study provides insights into liraglutide biology and suggests it may be an effective treatment for diabetic patients with wound-healing pathologies.

Unraveling the Functional Heterogeneity of Human Skin at Single-Cell Resolution

The skin consists of several cell populations, including epithelial, immune, and stromal cells. Recently, there has been a significant increase in single-cell RNA-sequencing studies, contributing to the development of a consensus Human Skin Cell Atlas. The aim is to understand skin biology better and identify potential therapeutic targets. The present review utilized previously published single-cell RNA-sequencing datasets to explore human skin's cellular and functional heterogeneity. Additionally, it summarizes the functional significance of newly identified cell subpopulations in processes such as wound healing and aging.

Combination therapy of negative pressure wound therapy and antibiotic-loaded bone cement for accelerating diabetic foot ulcer healing: A prospective randomised controlled trial

Negative pressure wound therapy (NPWT) and antibiotic-loaded bone cement (ALBC) are commonly used treatments for diabetic foot ulcers (DFUs). However, the combined efficacy of these two modalities remains unclear. This clinical study aimed to assess the effectiveness and underlying mechanisms of NPWT&ALBC in the management of DFUs. A total of 28 patients were recruited, 16 of whom served as controls and received only NPWT, whilst 12 received NPWT&ALBC. Both groups underwent wound repair surgery following the treatments. Blood samples were obtained to detect infections and inflammation. Wound tissue samples were also collected before and after the intervention to observe changes in inflammation, vascular structure and collagen through tissue staining. Compared with the NPWT group, the NPWT&ALBC group exhibited a superior wound bed, which was characterised by reduced inflammation infiltration and enhanced collagen expression. Immunostaining revealed a decrease in IL-6 levels and an increase in α-SMA, CD68, CD206 and collagen I expression. Western blot analysis demonstrated that NPWT&ALBC led to a decrease in inflammation levels and an increase in vascularization and collagen content. NPWT&ALBC therapy tends to form a wound bed with increased vascularization and M2 macrophage polarisation, which may contribute to DFUs wound healing.

Obstructed vein delivery of ceftriaxone via poly(vinyl-pyrrolidone)-iodine-chitosan nanofibers for the management of diabetic foot infections and burn wounds

Superficial skin injuries especially burn injuries and unhealed diabetic foot open wounds remain troubling for public health. The healing process is often interrupted by the invasion of resistant pathogens that results in the failure of conventional procedures outside the clinical settings. Herein, we designed nanofibers dressing with intrinsic antibacterial potential of poly(vinyl-pyrrolidone)-iodine/ poly (vinyl)-alcohol by electrospinning with chitosan encapsulating ceftriaxone (CPC/NFs). The optimized electrospun CPC/NFs exhibited smooth surface morphology with average diameter of 165 ± 7.1 nm, drug entrapment and loading efficiencies of 76.97 ± 4.7 % and 8.32 ± 1.73 %, respectively. The results displayed smooth and uniformed fibers with adequate thermal stability and ensured chemical doping. The enhanced in vitro antibacterial efficacy of CPC/NFs against resistant E. coli isolates and biosafety studies encourage the use of designed nanofibers dressing for burn injuries and diabetic foot injuries. In vivo studies proved the healing power of dressing for burn wounds model and diabetic infected wounds model. Immunofluorescence investigation of the wound tissue also suggested promising healing ability of CPC/NFs. The designed approach would be helpful to treat these infected skin open wounds in the hospitals and outside the clinical settings.

The Expression of MAFB Gene in Circulating Monocytes Is Related to Chronic Inflammatory Status in T2DM Patients

Immune cell-mediated chronic inflammation is one of the causes of type 2 diabetes mellitus (T2DM). Therefore, identifying inflammatory markers in circulating immune cells is highly important for predicting insulin resistance (IR) and the occurrence of T2DM. In this study, we discovered that differentially expressed genes (DEGs) in peripheral blood mononuclear cells (PBMCs) from T2DM patients were associated with innate immunity and chronic inflammatory responses through bulk transcriptome sequencing (bulk RNA-seq). Gene integration analysis revealed that nine DEGs were upregulated, and receiver operating characteristic (ROC) curve analysis revealed that V-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB), a candidate biomarker, has a certain predictive value for T2DM. In population-based cohort studies, we found that MAFB expression was significantly upregulated in the PBMCs of T2DM patients and was significantly correlated with homeostasis model assessment of IR (HOMA-IR), tumor necrosis factor-α (TNF-α), adiponectin (Adipoq), etc. We further evaluated the sensitivity and specificity of MAFB and other clinical parameters for predicting and diagnosing T2DM and found that MAFB expression in PBMCs had a positive effect on the prediction and diagnosis of T2DM. Finally, single-cell RNA sequencing (scRNA-seq) analysis revealed that the increase in MAFB expression was mainly in nonclassical monocytes. Our results suggest that increased MAFB expression in circulating monocytes may mediate chronic inflammatory status in patients with T2DM. Therefore, MAFB gene expression in circulating monocytes has certain clinical significance for predicting and assisting in the diagnosis of T2DM.

Chitinase‑3 like‑protein‑1: A potential predictor of cardiovascular disease (Review)

Chitinase‑3 like‑protein‑1 (CHI3L1), a glycoprotein belonging to the glycoside hydrolase family 18, binds to chitin; however, this protein lacks chitinase activity. Although CHI3L1 is not an enzyme capable of degrading chitin, it plays significant roles in abnormal glucose and lipid metabolism, indicating its involvement in metabolic disorders. In addition, CHI3L1 is considered a key player in inflammatory diseases, with clinical data suggesting its potential as a predictor of cardiovascular disease. CHI3L1 regulates the inflammatory response of various cell types, including macrophages, vascular smooth muscle cells and fibroblasts. In addition, CHI3L1 participates in vascular remodeling and fibrosis, contributing to the pathogenesis of cardiovascular disease. At present, research is focused on elucidating the role of CHI3L1 in cardiovascular disease. The present systematic review was conducted to comprehensively evaluate the effects of CHI3L1 on cardiovascular cells, and determine the potential implications in the occurrence and progression of cardiovascular disease. The present study may further the understanding of the involvement of CHI3L1 in cardiovascular pathology, demonstrating its potential as a therapeutic target or biomarker in the management of cardiovascular disease.

Characterization of Endothelial Cell Subclusters in Localized Scleroderma Skin with Single-Cell RNA Sequencing Identifies NOTCH Signaling Pathway

Localized scleroderma (LS) is an autoimmune disease characterized by inflammation and fibrosis, leading to severe cutaneous manifestations such as skin hardening, tightness, discoloration, and other textural changes that may result in disability. While LS shares similar histopathologic features and immune-fibroblast interactions with systemic sclerosis (SSc), its molecular mechanisms remain understudied. Endothelial cells (EC) are known to play a crucial role in SSc but have not been investigated in LS. Single-cell RNA sequencing (scRNA-seq) now allows for detailed examination of this cell type in the primary organ of interest for scleroderma, the skin. In this study, we analyzed skin-isolated cells from 27 LS patients (pediatric and adult) and 17 healthy controls using scRNA-seq. Given the known role of EC damage as an initial event in SSc and the histologic and clinical skin similarities to LS, we focused primarily on endothelial cells. Our analysis identified eight endothelial subclusters within the dataset, encompassing both disease and healthy samples. Interaction analysis revealed that signaling from diseased endothelial cells was predicted to promote fibrosis through SELE interaction with FGFBP1 and other target genes. We also observed high levels of JAG in arterial endothelial cells and NOTCH in capillary endothelial cells, indicating the activation of a signaling pathway potentially responsible for epidermal abnormalities and contributing to LS pathogenesis. In summary, our scRNA-seq analysis identified potential disease-propagating endothelial cell clusters with upregulated pathways in LS skin, highlighting their importance in disease progression.

Basal-to-inflammatory transition and tumor resistance via crosstalk with a pro-inflammatory stromal niche

Cancer-associated inflammation is a double-edged sword possessing both pro- and anti-tumor properties through ill-defined tumor-immune dynamics. While we previously identified a carcinoma tumor-intrinsic resistance pathway, basal-to-squamous cell carcinoma transition, here, employing a multipronged single-cell and spatial-omics approach, we identify an inflammation and therapy-enriched tumor state we term basal-to-inflammatory transition. Basal-to-inflammatory transition signature correlates with poor overall patient survival in many epithelial tumors. Basal-to-squamous cell carcinoma transition and basal-to-inflammatory transition occur in adjacent but distinct regions of a single tumor: basal-to-squamous cell carcinoma transition arises within the core tumor nodule, while basal-to-inflammatory transition emerges from a specialized inflammatory environment defined by a tumor-associated TREM1 myeloid signature. TREM1 myeloid-derived cytokines IL1 and OSM induce basal-to-inflammatory transition in vitro and in vivo through NF-κB, lowering sensitivity of patient basal cell carcinoma explant tumors to Smoothened inhibitor treatment. This work deepens our knowledge of the heterogeneous local tumor microenvironment and nominates basal-to-inflammatory transition as a drug-resistant but targetable tumor state driven by a specialized inflammatory microenvironment.

Use of Serum Protein Measurements as Biomarkers that Can Predict the Outcome of Diabetic Foot Ulceration

Objectives: To identify proteins that are prognostic for diabetic foot ulcer (DFU) healing and may serve as biomarkers for its management, serum samples were analyzed from diabetic mellitus (DM) patients. Approach: The serum specimens that were evaluated in this study were obtained from DM patients with DFU who participated in a prospective study and were seen biweekly until they healed their ulcer or the exit visit at 12 weeks. The group was divided into Healers (who healed their DFU during the study) and Non-Healers. Results: Interleukin (IL)-10, IL-4, IL-5, IL-6, and IL-13 and interferon-gamma were higher in the Healers while Fractalkine, IL-8, and TNFα were higher in the Non-Healers. The trajectory of IL-10 levels remained stable over time within and across groups, resulting in a strong prognostic ability for the prospective DFU healing course. Classification and Regression Tree analysis created an 11-node decision tree with healing status as the categorical response. Innovation: Consecutive measurements of proteins associated with wound healing can identify biomarkers that can predict DFU healing over a 12-week period. IL-10 was the strongest candidate for prediction. Conclusion: Measurement of serum proteins can serve as a successful strategy in guiding clinical management of DFU. The data also indicate likely superior performance of building a multiprotein biomarker score instead of relying on single biomarkers.

Macrophage and Neutrophil Dysfunction in Diabetic Wounds

Significance: The incidence of diabetes continues to rise throughout the world in an alarming rate. Diabetic patients often develop diabetic foot ulcers (DFUs), many of which do not heal. Non-healing DFUs are a major cause of hospitalization, amputation, and increased morbidity. Understanding the underlying mechanisms of impaired healing in DFU is crucial for its management. Recent Advances: This review focuses on the recent advancements on macrophages and neutrophils in diabetic wounds and DFUs. In particular, we discuss diabetes-induced dysregulations and dysfunctions of macrophages and neutrophils. Critical Issues: It is well established that diabetic wounds are characterized by stalled inflammation that results in impaired healing. Recent findings in the field suggest that dysregulation of macrophages and neutrophils plays a critical role in impaired healing in DFUs. The delineation of mechanisms that restore macrophage and neutrophil function in diabetic wound healing is the focus of intense investigation. Future Directions: The breadth of recently generated knowledge on the activity of macrophages and neutrophils in diabetic wound healing is impressive. Experimental models have delineated pathways that hold promise for the treatment of diabetic wounds and DFUs. These pathways may be useful targets for further clinical investigation.

Scupa: Single-cell unified polarization assessment of immune cells using the single-cell foundation model

Immune cells undergo cytokine-driven polarization in respond to diverse stimuli. This process significantly modulates their transcriptional profiles and functional states. Although single-cell RNA sequencing (scRNA-seq) has advanced our understanding of immune responses across various diseases or conditions, currently there lacks a method to systematically examine cytokine effects and immune cell polarization. To address this gap, we developed Single-cell unified polarization assessment (Scupa), the first computational method for comprehensive immune cell polarization analysis. Scupa is trained on data from the Immune Dictionary, which characterizes 66 cytokine-driven polarization states across 14 immune cell types. By leveraging the cell embeddings from the Universal Cell Embeddings model, Scupa effectively identifies polarized cells in new datasets generated from different species and experimental conditions. Applications of Scupa in independent datasets demonstrated its accuracy in classifying polarized cells and further revealed distinct polarization profiles in tumor-infiltrating myeloid cells across cancers. Scupa complements conventional single-cell data analysis by providing new insights into immune cell polarization, and it holds promise for assessing molecular effects or identifying therapeutic targets in cytokine-based therapies.

Water-powered, electronics-free dressings that electrically stimulate wounds for rapid wound closure

Chronic wounds affect ~2% of the U.S. population and increase risks of amputation and mortality. Unfortunately, treatments for such wounds are often expensive, complex, and only moderately effective. Electrotherapy represents a cost-effective treatment; however, its reliance on bulky equipment limits its clinical use. Here, we introduce water-powered, electronics-free dressings (WPEDs) that offer a unique solution to this issue. The WPED performs even under harsh conditions-situations wherein many present treatments fail. It uses a flexible, biocompatible magnesium-silver/silver chloride battery and a pair of stimulation electrodes; upon the addition of water, the battery creates a radial electric field. Experiments in diabetic mice confirm the WPED's ability to accelerate wound closure and promote healing by increasing epidermal thickness, modulating inflammation, and promoting angiogenesis. Across preclinical wound models, the WPED-treated group heals faster than the control with wound closure rates comparable to treatments requiring expensive biologics and/or complex electronics. The results demonstrate the WPED's potential as an effective and more practical wound treatment dressing.

Cellular and molecular mechanisms of skin wound healing

Wound healing is a complex process that involves the coordinated actions of many different tissues and cell lineages. It requires tight orchestration of cell migration, proliferation, matrix deposition and remodelling, alongside inflammation and angiogenesis. Whereas small skin wounds heal in days, larger injuries resulting from trauma, acute illness or major surgery can take several weeks to heal, generally leaving behind a fibrotic scar that can impact tissue function. Development of therapeutics to prevent scarring and successfully repair chronic wounds requires a fuller knowledge of the cellular and molecular mechanisms driving wound healing. In this Review, we discuss the current understanding of the different phases of wound healing, from clot formation through re-epithelialization, angiogenesis and subsequent scar deposition. We highlight the contribution of different cell types to skin repair, with emphasis on how both innate and adaptive immune cells in the wound inflammatory response influence classically studied wound cell lineages, including keratinocytes, fibroblasts and endothelial cells, but also some of the less-studied cell lineages such as adipocytes, melanocytes and cutaneous nerves. Finally, we discuss newer approaches and research directions that have the potential to further our understanding of the mechanisms underpinning tissue repair.

Janus liposozyme for the modulation of redox and immune homeostasis in infected diabetic wounds

Diabetic foot ulcers often become infected, leading to treatment complications and increased risk of loss of limb. Therapeutics to manage infection and simultaneously promote healing are needed. Here we report on the development of a Janus liposozyme that treats infections and promotes wound closure and re-epithelialization. The Janus liposozyme consists of liposome-like selenoenzymes for reactive oxygen species (ROS) scavenging to restore tissue redox and immune homeostasis. The liposozymes are used to encapsulate photosensitizers for photodynamic therapy of infections. We demonstrate application in methicillin-resistant Staphylococcus aureus-infected diabetic wounds showing high ROS levels for antibacterial function from the photosensitizer and nanozyme ROS scavenging from the liposozyme to restore redox and immune homeostasis. We demonstrate that the liposozyme can directly regulate macrophage polarization and induce a pro-regenerative response. By employing single-cell RNA sequencing, T cell-deficient Rag1-/- mice and skin-infiltrated immune cell analysis, we further reveal that IL-17-producing γδ T cells are critical for mediating M1/M2 macrophage transition. Manipulating the local immune homeostasis using the liposozyme is shown to be effective for skin wound repair and tissue regeneration in mice and mini pigs.

Macrophage plasticity: signaling pathways, tissue repair, and regeneration

Macrophages are versatile immune cells with remarkable plasticity, enabling them to adapt to diverse tissue microenvironments and perform various functions. Traditionally categorized into classically activated (M1) and alternatively activated (M2) phenotypes, recent advances have revealed a spectrum of macrophage activation states that extend beyond this dichotomy. The complex interplay of signaling pathways, transcriptional regulators, and epigenetic modifications orchestrates macrophage polarization, allowing them to respond to various stimuli dynamically. Here, we provide a comprehensive overview of the signaling cascades governing macrophage plasticity, focusing on the roles of Toll-like receptors, signal transducer and activator of transcription proteins, nuclear receptors, and microRNAs. We also discuss the emerging concepts of macrophage metabolic reprogramming and trained immunity, contributing to their functional adaptability. Macrophage plasticity plays a pivotal role in tissue repair and regeneration, with macrophages coordinating inflammation, angiogenesis, and matrix remodeling to restore tissue homeostasis. By harnessing the potential of macrophage plasticity, novel therapeutic strategies targeting macrophage polarization could be developed for various diseases, including chronic wounds, fibrotic disorders, and inflammatory conditions. Ultimately, a deeper understanding of the molecular mechanisms underpinning macrophage plasticity will pave the way for innovative regenerative medicine and tissue engineering approaches.

Biologically Active Sheep Colostrum for Topical Treatment and Skin Care

Colostrum is gaining popularity in cosmetic products. The present study compared the composition and selected biological properties of colostrum from Polish sheep (colostrum 1) and Swiss sheep (colostrum 2), particularly those that can affect healthy or diseased skin. The antioxidant activity of the colostrums was measured using ABTS and DPPH assays. The effect on the proliferation of human skin fibroblasts, neonatal epidermal keratinocytes, and human diabetic fibroblast (dHF) cells isolated from diabetic foot ulcers was also assayed in vitro by MTT and Presto Blue tests, respectively. The colostrum simulated dHF cell proliferation by up to 115.4%. The highest used concentration of colostrum 1 stimulated normal fibroblast proliferation by 191.2% (24 h) and 222.2% (48 h). Both colostrums inhibited epidermal keratinocyte viability. The influence of the colostrums on the expression of genes related to proliferation (Ki67) and immune response (IL-6, PTGS-2, TSG-6) in dHF cells were compared. Colostrum 1 increased the rate of wound closure (scar test). Analysis of total fat, protein and fatty acid content found the Polish colostrum to be a richer source of fat than the Swiss colostrum, which contained a larger amount of protein. Both colostrums exhibit properties that suggest they could be effective components in cosmetic or medicinal formulations for skin care, especially supporting its regeneration, rejuvenation, and wound healing.

Molecular immunological mechanisms of impaired wound healing in diabetic foot ulcers (DFU), current therapeutic strategies and future directions

Diabetic foot ulcer (DFU) is a foremost cause of amputation in diabetic patients. Consequences of DFU include infections, decline in limb function, hospitalization, amputation, and in severe cases, death. Immune cells including macrophages, regulatory T cells, fibroblasts and other damage repair cells work in sync for effective healing and in establishment of a healthy skin barrier post-injury. Immune dysregulation during the healing of wounds can result in wound chronicity. Hyperglycemic conditions in diabetic patients influence the pathophysiology of wounds by disrupting the immune system as well as promoting neuropathy and ischemic conditions, making them difficult to heal. Chronic wound microenvironment is characterized by increased expression of matrix metalloproteinases, reactive oxygen species as well as pro-inflammatory cytokines, resulting in persistent inflammation and delayed healing. Novel treatment modalities including growth factor therapies, nano formulations, microRNA based treatments and skin grafting approaches have significantly augmented treatment efficiency, demonstrating creditable efficacy in clinical practices. Advancements in local treatments as well as invasive methodologies, for instance formulated wound dressings, stem cell applications and immunomodulatory therapies have been successful in targeting the complex pathophysiology of chronic wounds. This review focuses on elucidating the intricacies of emerging physical and non-physical therapeutic interventions, delving into the realm of advanced wound care and comprehensively summarizing efficacy of evidence-based therapies for DFU currently available.

Engineered exosomes as a prospective therapy for diabetic foot ulcers

Diabetic foot ulcer (DFU), characterized by high recurrence rate, amputations and mortality, poses a significant challenge in diabetes management. The complex pathology involves dysregulated glucose homeostasis leading to systemic and local microenvironmental complications, including peripheral neuropathy, micro- and macro-angiopathy, recurrent infection, persistent inflammation and dysregulated re-epithelialization. Novel approaches to accelerate DFU healing are actively pursued, with a focus on utilizing exosomes. Exosomes are natural nanovesicles mediating cellular communication and containing diverse functional molecular cargos, including DNA, mRNA, microRNA (miRNA), lncRNA, proteins, lipids and metabolites. While some exosomes show promise in modulating cellular function and promoting ulcer healing, their efficacy is limited by low yield, impurities, low loading content and inadequate targeting. Engineering exosomes to enhance their curative activity represents a potentially more efficient approach for DFUs. This could facilitate focused repair and regeneration of nerves, blood vessels and soft tissue after ulcer development. This review provides an overview of DFU pathogenesis, strategies for exosome engineering and the targeted therapeutic application of engineered exosomes in addressing critical pathological changes associated with DFUs.

Monoclonal Antibodies in the Management of Inflammation in Wound Healing: An Updated Literature Review

Chronic wounds pose a significant clinical challenge due to their complex pathophysiology and the burden of long-term management. Monoclonal antibodies (mAbs) are emerging as a novel therapeutic option in managing difficult wounds, although comprehensive data on their use in wound care are lacking. This study aimed to explore existing scientific knowledge of mAbs in treating chronic wounds based on a rationale of direct inhibition of the main molecules involved in the underlying inflammatory pathophysiology. We performed a literature review excluding primary inflammatory conditions with potential ulcerative outcomes (e.g., hidradenitis suppurativa). mAbs were effective in treating wounds from 16 different etiologies. The most commonly treated conditions were pyoderma gangrenosum (treated with 12 different mAbs), lipoid necrobiosis, and cutaneous vasculitis (each treated with 3 different mAbs). Fourteen mAbs were analyzed in total. Rituximab was effective in 43.75% of cases (7/16 diseases), followed by tocilizumab (25%, 4/16 diseases), and both etanercept and adalimumab (18.75%, 3/16 conditions each). mAbs offer therapeutic potential for chronic wounds unresponsive to standard treatments. However, due to the complex molecular nature of wound healing, no single target molecule can be identified. Therefore, the use of mAbs should be considered as a translational approach for limited cases of multi-resistant conditions.

Multi-omics analysis of diabetic pig lungs reveals molecular derangements underlying pulmonary complications of diabetes mellitus

Growing evidence shows that the lung is an organ prone to injury by diabetes mellitus. However, the molecular mechanisms of these pulmonary complications have not yet been characterized comprehensively. To systematically study the effects of insulin deficiency and hyperglycaemia on the lung, we combined proteomics and lipidomics with quantitative histomorphological analyses to compare lung tissue samples from a clinically relevant pig model for mutant INS gene-induced diabetes of youth (MIDY) with samples from wild-type littermate controls. Among others, the level of pulmonary surfactant-associated protein A (SFTPA1), a biomarker of lung injury, was moderately elevated. Furthermore, key proteins related to humoral immune response and extracellular matrix organization were significantly altered in abundance. Importantly, a lipoxygenase pathway was dysregulated as indicated by 2.5-fold reduction of polyunsaturated fatty acid lipoxygenase ALOX15 levels, associated with corresponding changes in the levels of lipids influenced by this enzyme. Our multi-omics study points to an involvement of reduced ALOX15 levels and an associated lack of eicosanoid switching as mechanisms contributing to a proinflammatory milieu in the lungs of subjects with diabetes mellitus.

Combined analysis of single-cell sequencing and bulk transcriptome sequencing reveals new mechanisms for non-healing diabetic foot ulcers

Diabetic foot ulcers (DFUs) pose a significant challenge in diabetes care. Yet, a comprehensive understanding of the underlying biological disparities between healing and non-healing DFUs remains elusive. We conducted bioinformatics analysis of publicly available transcriptome sequencing data in an attempt to elucidate these differences. Our analysis encompassed differential analysis to unveil shifts in cell composition and gene expression profiles between non-healing and healing DFUs. Cell communication alterations were explored employing the Cellchat R package. Pseudotime analysis and cytoTRACE allowed us to dissect the heterogeneity within fibroblast subpopulations. Our findings unveiled disruptions in various cell types, localized low-grade inflammation, compromised systemic antigen processing and presentation, and extensive extracellular matrix signaling disarray in non-healing DFU patients. Some of these anomalies partially reverted in healing DFUs, particularly within the abnormal ECM-receptor signaling pathway. Furthermore, we distinguished distinct fibroblast subpopulations in non-healing and healing DFUs, each with unique biological functions. Healing-associated fibroblasts exhibited heightened extracellular matrix (ECM) remodeling and a robust wound healing response, while non-healing-associated fibroblasts showed signs of cellular senescence and complement activation, among other characteristics. This analysis offers profound insights into the wound healing microenvironment, identifies pivotal cell types for DFU healing promotion, and reveals potential therapeutic targets for DFU management.

Correlation between changes in serum YKL-40, LXRs, PPM1A, and TGF-β1 levels and airway remodeling and lung function in patients with bronchial asthma

OBJECTIVE

This study investigates the correlation between serum levels of YKL-40, LXRs, PPM1A, and TGF-β1 and airway remodeling and lung function in bronchial asthma patients.

METHODS

The study involved 80 bronchial asthma patients and 92 healthy individuals. Serum cytokines, airway remodeling, and lung function markers were compared across mild, moderate, and severe asthma cases using high-resolution CT, t-tests, ANOVA, and Pearson correlation analysis.

RESULTS

Asthmatic patients exhibited higher levels of serum YKL-40, LXRα, LXRβ, TGF-β1, airway wall thickness (T)/outer diameter (D), and WA% of total cross-sectional area compared to controls. Conversely, their serum PPM1A, Peak Expiratory Flow (PEF), and Forced Expiratory Volume in 1 s (FEV1) were lower. Serum YKL-40 and TGF-β1 levels were positively correlated with T/D and WA%, and negatively correlated with PEF and FEV1. PPM1A levels were strongly associated with T/D, WA%, PEF, and FEV1.

CONCLUSION

The severity of bronchial asthma is associated with increased serum levels of YKL-40, LXRα, LXRβ, and TGF-β1 and decreased PPM1A. The levels of YKL-40, PPM1A, and TGF-β1 have a significant correlation with airway remodeling and lung function.

Development of novel lysosome-related signatures and their potential target drugs based on bulk RNA-seq and scRNA-seq for diabetic foot ulcers

BACKGROUND

Diabetic foot ulcers (DFU) is the most serious complication of diabetes mellitus, which has become a global health problem due to its high morbidity and disability rates and the poor efficacy of conventional treatments. Thus, it is urgent to identify novel molecular targets to improve the prognosis and reduce disability rate in DFU patients.

RESULTS

In the present study, bulk RNA-seq and scRNA-seq associated with DFU were downloaded from the GEO database. We identified 1393 DFU-related DEGs by differential analysis and WGCNA analysis together, and GO/KEGG analysis showed that these genes were associated with lysosomal and immune/inflammatory responses. Immediately thereafter, we identified CLU, RABGEF1 and ENPEP as DLGs for DFU using three machine learning algorithms (Randomforest, SVM-RFE and LASSO) and validated their diagnostic performance in a validation cohort independent of this study. Subsequently, we constructed a novel artificial neural network model for molecular diagnosis of DFU based on DLGs, and the diagnostic performance in the training and validation cohorts was sound. In single-cell sequencing, the heterogeneous expression of DLGs also provided favorable evidence for them to be potential diagnostic targets. In addition, the results of immune infiltration analysis showed that the abundance of mainstream immune cells, including B/T cells, was down-regulated in DFUs and significantly correlated with the expression of DLGs. Finally, we found latamoxef, parthenolide, meclofenoxate, and lomustine to be promising anti-DFU drugs by targeting DLGs.

CONCLUSIONS

CLU, RABGEF1 and ENPEP can be used as novel lysosomal molecular signatures of DFU, and by targeting them, latamoxef, parthenolide, meclofenoxate and lomustine were identified as promising anti-DFU drugs. The present study provides new perspectives for the diagnosis and treatment of DFU and for improving the prognosis of DFU patients.

Translational Challenges in Drug Therapy and Delivery Systems for Treating Chronic Lower Extremity Wounds

Despite several promising preclinical studies performed over the past two decades, there remains a paucity of market-approved drugs to treat chronic lower extremity wounds in humans. This translational gap challenges our understanding of human chronic lower extremity wounds and the design of wound treatments. Current targeted drug treatments and delivery systems for lower extremity wounds rely heavily on preclinical animal models meant to mimic human chronic wounds. However, there are several key differences between animal preclinical wound models and the human chronic wound microenvironment, which can impact the design of targeted drug treatments and delivery systems. To explore these differences, this review delves into recent new drug technologies and delivery systems designed to address the chronic wound microenvironment. It also highlights preclinical models used to test drug treatments specific for the wound microenvironments of lower extremity diabetic, venous, ischemic, and burn wounds. We further discuss key differences between preclinical wound models and human chronic wounds that may impact successful translational drug treatment design.

Single-cell sequencing reveals distinct immune cell features in cutaneous lesions of pemphigus vulgaris and bullous pemphigoid

Bullous pemphigoid (BP) and pemphigus vulgaris (PV) are two common subtypes of autoimmune bullous disease (AIBD). The key role of circulating autoreactive immune cells contributing to skin damage of AIBD has been widely recognized. Nevertheless, the immune characteristics in cutaneous lesions remain unclear. Here, we performed single-cell RNA sequencing (scRNA-seq) and single-cell VDJ sequencing (scRNA-seq) to generate transcriptional profiles for cells and T/B cell clonetype in skin lesions of BP and PV. We found that the proportions of NK&T, macrophages/ dendritic cells, B cells, and mast cells increased in BP and PV lesions. Then, BP and PV cells constituted over 75% of all myeloid cell subtypes, CD4+ T cell subtypes and CD8+ T cell subtypes. Strikingly, CD8+ Trm was identified to be expanded in PV, and located in the intermediate state of the pseudotime trajectory from CD8+ Tm to CD8+ Tem. Interestingly, CD8+ Tem and CD4+ Treg highly expressed exhaustion-related genes, especially in BP lesions. Moreover, the enhanced cell communication between stromal cells and immune cells like B cells and macrophages/ dendritic cells was also identified in BP and PV lesions. Finally, clone expansion was observed in T cells of BP and PV compared with HC, while CD8+ Trm represented the highest ratio of hyperexpanded TCR clones among all T cell subtypes. Our study generally depicts a large and comprehensive single-cell landscape of cutaneous lesions and highlights immune cell features in BP and PV. This offers potential research targets for further investigation.