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.

The Role of Macrophage Efferocytosis in the Pathogenesis of Apical Periodontitis

Macrophages (Mφs) play a crucial role in the homeostasis of the periapical immune micro-environment caused by bacterial infection. Mφ efferocytosis has been demonstrated to promote the resolution of multiple infected diseases via accelerating Mφ polarization into M2 type. However, the Mφ efferocytosis-apical periodontitis (AP) relationship has not been elucidated yet. This study aimed to explore the role of Mφ efferocytosis in the pathogenesis of AP. Clinical specimens were collected to determine the involvement of Mφ efferocytosis in the periapical region via immunohistochemical and immunofluorescence staining. For a further understanding of the moderator effect of Mφ efferocytosis in the pathogenesis of AP, both an in vitro AP model and in vivo AP model were treated with ARA290, a Mφ efferocytosis agonist. Histological staining, micro-ct, flow cytometry, RT-PCR and Western blot analysis were performed to detect the inflammatory status, alveolar bone loss and related markers in AP models. The data showed that Mφ efferocytosis is observed in the periapical tissues and enhancing the Mφ efferocytosis ability could effectively promote AP resolution via facilitating M2 Mφ polarization. Collectively, our study demonstrates the functional importance of Mφ efferocytosis in AP pathology and highlights that accelerating Mφ efferocytosis via ARA290 could serve as an adjuvant therapeutic strategy for AP.