Preclinical study of diabetic foot ulcers: From pathogenesis to vivo/vitro models and clinical therapeutic transformation

Single-cell RNA sequencing reveals a new mechanism of endothelial cell heterogeneity and healing in diabetic foot ulcers

Diabetic foot ulcers (DFU) are a common and severe complication among diabetic patients, posing a significant burden on patients' quality of life and healthcare systems due to their high incidence, amputation rates, and mortality. This study utilized single-cell RNA sequencing technology to deeply analyze the cellular heterogeneity of the skin on the feet ofDFU patients and the transcriptomic characteristics of endothelial cells, aiming to identify key cell populations and genes associated with the healing and progression of DFU. The study found that endothelial cells from DFU patients exhibited significant transcriptomic differences under various conditions, particularly in signaling pathways related to inflammatory responses and angiogenesis. Through trajectory analysis and cell communication research, we revealed the key role of endothelial cell subsets in the development of DFU and identified multiple important gene modules associated with the progression of DFU. Notably, the promoting effect of the SH3BGRL3 gene on endothelial cell proliferation, migration, and angiogenic capabilities under high glucose conditions was experimentally verified, providing a new potential target and theoretical basis for the treatment of DFU. This study not only enhances the understanding of the pathogenesis ofDFU but also provides a scientific basis for the development ofnew therapeutic strategies.

Optimizing risk management for post-amputation wound complications in diabetic patients: Focus on glycemic and immunosuppressive control

This study highlights the importance of identifying and addressing risk factors associated with wound complications following transtibial amputation in diabetic patients. These amputations, often necessitated by severe diabetic foot ulcers, carry significant risks of postoperative complications such as infection and delayed wound healing. Elevated hemoglobin A1c levels, indicative of poor glycemic control, and a history of kidney transplantation, due to required immunosuppressive therapy, are key factors influencing these outcomes. This paper emphasizes the need for enhanced glycemic management and personalized postoperative care, particularly for immunocompromised individuals, to minimize complications and improve patient prognosis. Future research should focus on prospective studies to validate targeted interventions and optimize care strategies, ultimately aiming to reduce the healthcare burden associated with diabetic foot complications.

Psychological stress level surveys in patients with diabetic foot ulcers and the application effect of using loofah sponges during VSD treatment

OBJECTIVE

To investigate the psychological stress levels in patients with diabetic foot ulcer (DFU) and evaluate the effects of using a luffa sponge in vacuum sealing drainage (VSD) treatment.

METHODS

This retrospective study analyzed the clinical data from 110 DFU patients treated with VSD at The First People's Hospital of Zunyi (The Third Affiliated Hospital of Zunyi Medical University) between September 2021 and October 2023. Patients were categorized into two groups based on psychological stress levels: an observation group (with psychological stress, n=42) and a control group (without psychological stress, n=68). Baseline data were analyzed to identify factors influencing psychological stress. The observation group was further divided into the conventional care group and the loofah fiber care group, each with 21 patients, to evaluate the effect of using a loofah sponge during VSD treatment.

RESULTS

Logistic regression analysis identified Wagner classification and diabetes-related distress levels as significant factors influencing psychological stress (P<0.05). Post-intervention, the loofah fiber care group showed significantly lower scores on HQ-9, GAD-7, and SRSS (all P<0.05). Additionally, the loofah fiber care group showed lower frequencies of ASD dressing changes, shorter wound healing times, shorter hospital stays, and lower VAS pain scores (all P<0.05). Quality of life scores were significantly higher in the loofah fiber care group across all dimensions (P<0.05), and DASS-21 scores were significantly lower post-intervention (P<0.05). The loofah fiber care group also demonstrated significantly better outcomes in Wagner classification and diabetes-related distress levels, with higher patient satisfaction (all P<0.05).

CONCLUSION

This study highlights significant factors influencing psychological stress in patients with DFU and demonstrates that loofah fiber nursing interventions during VSD treatment improve psychological stress, wound healing, and quality of life. This method provides a promising approach to enhance patient outcomes and satisfaction.

Evaluation of wound temperature monitoring at various anatomical sites in the management of patients with diabetic foot undergoing microcirculation reconstruction

OBJECTIVE

This study aims to assess the significance of monitoring temperature change trends at various wound sites in the healing process of diabetic foot ulcers after microcirculation reconstruction surgery.

METHODS

A retrospective analysis was conducted on individuals with diabetic foot ulcers who had been admitted to the Department of Orthopedics at the Second Hospital of Shanxi Medical University between July 2020 and February 2022. Temperature changes were regularly monitored at the center of the wound and the distal tibia of the ipsilateral lower leg to assess microcirculatory blood perfusion. Wound, ischemia, and foot infection (WIFi) grading was performed at admission and the final follow-up was to determine the value of temperature monitoring at various sites. Additionally, the formation of collateral microarterial vessels was monitored to determine their consistency with the observed trends in temperature differences. Follow-up assessments included the recurrence of ulcers, development of ulcers at different locations, re-amputation of the toe or limb, and diabetes-related mortality.

RESULTS

A total of 29 patients were included in the follow-up, with an average age of 57.14 ± 14.75 years and a follow-up period of 9.79 ± 4.13 months. Following microcirculation reconstruction surgery, as the microvascular network formed, the temperature difference between the center of the wound and the distal tibia on the same side gradually decreased, with no statistical difference observed at 4 weeks postoperatively. At both admission and the final follow-up, there was a significant reduction in the wound (W) and ischemia (I) grades within the WIFi classification. The temperature at the wound center showed progressive improvement as collateral microarterial vessels developed. During the follow-up period, there were 2 cases of ulcer recurrence, 1 case of an ulcer appearing at a different location, no cases of re-amputation of the toe or limb, and 2 diabetes-related fatalities.

CONCLUSION

Skin temperature monitoring offers a direct and reliable indication of microcirculatory blood perfusion. Its simplicity and cost-effectiveness make it a valuable tool for widespread use in evaluating wound healing following microcirculation reconstruction surgery.

Immunomodulation of Macrophages in Diabetic Wound Individuals by Structurally Diverse Bioactive Phytochemicals

Diabetes-related ulcers and slow-healing wounds pose a significant health risk to individuals due to their uncertain causes. Mortality rates for diabetes foot ulcers (DFUs) range from 10% after 16 months to 24% after five years. The use of bioactive phytochemicals can play a key role in healing wounds in a predictable time. Recent literature has demonstrated that various natural substances, including flavonoids, saponins, phenolic compounds, and polysaccharides, play key roles at different stages of the wound-healing process through diverse mechanisms. These studies have categorized the compounds according to their characteristics, bioactivities, and modes of action. In this study, we evaluated the role of natural compounds derived from plant sources that have been shown to play a crucial role in immunomodulation. Macrophages are closely involved in immunomodulation within the wound microenvironment and are key players in efferocytosis, inflammation resolution, and tissue regeneration, all of which contribute to successful wound healing. Phytochemicals and their derivatives have shown capabilities in immune regulation, including macrophage migration, nitric oxide synthase inhibition, lymphocyte and T-cell stimulation, cytokine activation, natural killer cell enhancement, and the regulation of NF-κβ, TNF-α, and apoptosis. In this review, we have studied the role of phytochemicals in immunomodulation for the resolution of diabetic wound inflammation.

Local Management for Diabetic Foot Ulcers: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

OBJECTIVE

This study evaluated the efficacy of various local management strategies for diabetic foot ulcers (DFUs).

BACKGROUND

Several surgical and non-surgical local interventional approaches are available for the treatment of DFUs. The comparative effectiveness of different treatments is unknown, and it remains unclear which approach is the optimal choice for DFUs treatment due to limited direct comparisons.

METHODS

We did a systematic review and meta-analysis to select the optimal approach to DFUs local management. We searched Medline, Embase, Web of Science, and ClinicalTrials.gov from inception to September 1, 2023, to identify relevant randomized controlled trials (RCTs). We analysed data by pairwise meta-analyses with a random-effects model. A network meta-analysis using the surface under the cumulative ranking curve (SUCRA) was performed to evaluate the comparative efficacy of different interventional approaches in the early (within 12 wk) and late stages (over 12 wk).

RESULTS

141 RCTs involving 14076 patients and exploring 14 interventional strategies were eligible for inclusion. Most studies (102/141) had at least one risk-of-bias dimension. Good consistency was observed during the analysis. Local pairwise comparisons demonstrated obvious differences in the early-stage healing rate and early- and late-stage healing times, while no significant difference in the late-stage healing rate or adverse events were noted. SUCRAs identified the standard of care (SOC) + decellularized dressing (DD), off-loading (OL), and autogenous graft (AG) as the three most effective interventions within 12 weeks for both healing rate (97%, mean rank: 1.4; 90%, mean rank: 2.3; 80.8%, mean rank: 3.5, respectively) and healing time (96.7%, mean rank: 1.4; 83.0%, mean rank: 3.0; 76.8%, mean rank: 3.8, respectively). After 12 weeks, local drug therapy (LDT) (89.5%, mean rank: 2.4) and OL (82.4%, mean rank: 3.3) ranked the highest for healing rate, and OL (100.0%, mean rank: 1.0) for healing time. With respect to adverse events, moderate and high risks were detected in the SOC + DD (53.7%, mean rank: 7.0) and OL (24.4%, mean rank: 10.8) groups, respectively.

CONCLUSION

The findings suggest that OL provided considerable benefits for DFU healing in both the early and late stages, but the high risk of adverse events warrants caution. SOC+DD may be the preferred option in the early stages, with an acceptable risk of adverse events.

PROS1 is a crucial gene in the macrophage efferocytosis of diabetic foot ulcers: a concerted analytical approach through the prisms of computer analysis

BACKGROUND

Diabetic foot ulcers (DFUs) pose a serious long-term threat because of elevated mortality and disability risks. Research on its biomarkers is still, however, very limited. In this paper, we have effectively identified biomarkers linked with macrophage excretion in diabetic foot ulcers through the application of bioinformatics and machine learning methodologies. These findings were subsequently validated using external datasets and animal experiments. Such discoveries are anticipated to offer novel insights and approaches for the early diagnosis and treatment of DFU.

METHODS

In this work, we used the Gene Expression Omnibus (GEO) database's datasets GSE68183 and GSE80178 as the training dataset to build a gene model using machine learning methods. After that, we used the training and validation sets to validate the model (GSE134431). On the model genes, we performed enrichment analysis using both gene set variant analysis (GSVA) and gene set enrichment analysis (GSEA). Additionally, the model genes were subjected to immunological association and immune function analyses.

RESULTS

In this study, PROS1 was identified as a potential key target associated with macrophage efflux in DFU by machine learning and bioinformatics approaches. Subsequently, the key biomarker status of PROS1 in DFU was also confirmed by external datasets. In addition, PROS1 also plays a key role in macrophage exudation in DFU. This gene may be associated with macrophage M1, CD4 memory T cells, naïve B cells, and macrophage M2, and affects IL-17, Rap1, hedgehog, and JAK-STAT signaling pathways.

CONCLUSIONS

PROS1 was identified and validated as a biomarker for DFU. This finding has the potential to provide a target for macrophage clearance of DFU.

Animal Models of Type 2 Diabetes Complications: A Review

Diabetes mellitus is a multifactorial metabolic disease, of which type 2 diabetes (T2D) is one of the most common. The complications of diabetes are far more harmful than diabetes itself. Type 2 diabetes complications include diabetic nephropathy (DN), diabetic heart disease, diabetic foot ulcers (DFU), diabetic peripheral neuropathy (DPN), and diabetic retinopathy (DR) et al. Many animal models have been developed to study the pathogenesis of T2D and discover an effective strategy to treat its consequences. In this sense, it is crucial to choose the right animal model for the corresponding diabetic complication. This paper summarizes and classifies the animal modeling approaches to T2D complications and provides a comprehensive review of their advantages and disadvantages. It is hopeful that this paper will provide theoretical support for animal trials of diabetic complications.

Identifying and Validating GSTM5 as an Immunogenic Gene in Diabetic Foot Ulcer Using Bioinformatics and Machine Learning

Background

A diabetic foot ulcer (DFU) is a serious, long-term condition associated with a significant risk of disability and mortality. However, research on its biomarkers is still limited. This study utilizes bioinformatics and machine learning methods to identify immune-related biomarkers for DFU and validates them through external datasets and animal experiments.

Methods

This study used bioinformatics and machine learning to analyze microarray data from the Gene Expression Omnibus (GEO) database to identify key genes associated with DFU. Animal experiments were conducted to validate these findings. This research employs the datasets GSE68183 and GSE80178 retrieved from the GEO database as the training dataset for building a gene machine learning model, and after conducting differential analysis on the data, this study used package glmnet and package e1071 to construct LASSO and SVM-RFE machine learning models, respectively. Subsequently, we validated the model using the training set and validation set (GSE134431). We conducted enrichment analysis, including GSEA and GSVA, on the model genes. We also performed immune functional analysis and immune-related analysis on the model genes. Finally, we conducted immunohistochemistry (IHC) validation on the model genes.

Results

This study identifies GSTM5 as a potential immune-related key target in DFU using machine learning and bioinformatics methods. Subsequent validation through external datasets and IHC experiments also confirms GSTM5 as a critical biomarker for DFU. The gene may be associated with T cells regulatory (Tregs) and T cells follicular helper, and it influences the NF-κB, GnRH, and MAPK signaling pathway.

Conclusion

This study identified and validated GSTM5 as a biomarker for DFU. This finding may potentially provide a target for immune therapy for DFU.

Preclinical study of diabetic foot ulcers: From pathogenesis to vivo/vitro models and clinical therapeutic transformation

Diabetic foot ulcer (DFU), a common intractable chronic complication of diabetes mellitus (DM), has a prevalence of up to 25%, with more than 17% of the affected patients at risk of amputation or even death. Vascular risk factors, including vascular stenosis or occlusion, dyslipidemia, impaired neurosensory and motor function, and skin infection caused by trauma, all increase the risk of DFU in patients with diabetes. Therefore, diabetic foot is not a single pathogenesis. Preclinical studies have contributed greatly to the pathogenesis determination and efficacy evaluation of DFU. Many therapeutic tools are currently being investigated using DFU animal models for effective clinical translation. However, preclinical animal models that completely mimic the pathogenesis of DFU remain unexplored. Therefore, in this review, the preparation methods and evaluation criteria of DFU animal models with three major pathological mechanisms: neuropathy, angiopathy and DFU infection were discussed in detail. And the advantages and disadvantages of various DFU animal models for clinical sign simulation. Furthermore, the current status of vitro models of DFU and some preclinical studies have been transformed into clinical treatment programs, such as medical dressings, growth factor therapy, 3D bioprinting and pre-vascularization, Traditional Chinese Medicine treatment. However, because of the complexity of the pathological mechanism of DFU, the clinical transformation of DFU model still faces many challenges. We need to further optimize the existing preclinical studies of DFU to provide an effective animal platform for the future study of pathophysiology and clinical treatment of DFU.

Mouse models of diabetes-related ulcers: a systematic review and network meta-analysis

BACKGROUND

Diabetic foot ulcers (DFUs) are a common complication of diabetes, associated with important morbidity. Appropriate animal models of DFUs may improve drug development, and subsequently the success rate of clinical trials. However, while many models have been proposed, they are extremely heterogeneous, and no standard has emerged. We thus propose a systematic review with a network meta-analysis (NMA) to gather direct and indirect evidence, and compare the different mouse models of diabetes-related ulcers.

METHODS

The systematic search was performed in Pubmed and Embase. The main outcomes were wound size measurement at days 3, 7, 11 and 15 (±1 day). The risk of bias and methodological quality of all included studies was assessed by using the Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias tool. Meta-regressions were done on prespecified variables, including mouse strain, type of ulcer, sex, age, and use of a splint.

FINDINGS

We included 295 studies. Among all models, only db/db, ob/ob, streptozotocin (STZ), and STZ + high fat diet mice showed a significantly delayed wound healing, compared with controls, at each time point. Age, sex and ulcer type had influence on wound healing, although not at all time points.

INTERPRETATION

In conclusion, the db/db model is associated with the largest delay in wound healing The STZ model also exhibits significantly decreased wound healing. STZ + high fat diet and ob/ob mice may also be relevant models of diabetes-related ulcers, although the results rely on a more limited number of studies.

FUNDING

This work was funded by the Agence Nationale de la Recherche (grant ANR-18-CE17-0017).

Thou shall not heal: Overcoming the non-healing behaviour of diabetic foot ulcers by engineering the inflammatory microenvironment

Diabetic foot ulcers (DFUs) are a devastating complication for diabetic patients that have debilitating effects and can ultimately lead to limb amputation. Healthy wounds progress through the phases of healing leading to tissue regeneration and restoration of the barrier function of the skin. In contrast, in diabetic patients dysregulation of these phases leads to chronic, non-healing wounds. In particular, unresolved inflammation in the DFU microenvironment has been identified as a key facet of chronic wounds in hyperglyceamic patients, as DFUs fail to progress beyond the inflammatory phase and towards resolution. Thus, control over and modulation of the inflammatory response is a promising therapeutic avenue for DFU treatment. This review discusses the current state-of-the art regarding control of the inflammatory response in the DFU microenvironment, with a specific focus on the development of biomaterials-based delivery strategies and their cargos to direct tissue regeneration in the DFU microenvironment.