Background Patients with diabetic feet are prone to be infected due to the impaired immune system. However, the prognostic outcome of different microbial infections remains controversial. Identification and rapid screening of the pathogenic microorganisms that pose the greatest threat to the prognosis of patients with diabetic foot infections (DFIs) is critical. Methods Clinical data were statistically analyzed, which were obtained from 522 patients with DFIs, including pathogenic bacterial culture results and treatment outcomes at the last return visit. In addition, a loop-mediated isothermal amplification (LAMP) detection method was developed to identify the prevalent subtype of methicillin-resistant Staphylococcus aureus (MRSA) in DFIs patients. This study was approved by the Ethics Committee of Nanfang Hospital (NFEC-202012-K6) and registered on ClinicalTrials.gov (NCT04916457) on June 1, 2021. Results We found that the proportion of patients with infections of Staphylococcus aureus ( S. aureus ) and MRSA was 27.7% (145/522) and 33.7% (49/145), respectively. Additionally, the incidence of osteomyelitis was 46.9% (23/49) and amputation/disability was 40.8% (20/49) in patients with MRSA infection, which were significantly higher compared to patients with other types of bacterial infections such as methicillin-susceptible Staphylococcus aureus (MSSA). Notably, we demonstrated that the main prevalent subtype of MRSA in DFIs patients in our hospital was Staphylococcal chromosomal cassettes mec (SCCmec) type II. In addition, it only takes 1.5 h to complete the entire experimental procedure in this LAMP assay, providing high sensitivity (100%) and specificity (77.8%) in hospitalized patients with DFIs. Conclusions We demonstrated there is a very high rate of MRSA isolation in patients with DFIs and revealed that patients infected with MRSA are at a higher risk of developing osteomyelitis, and amputation or disability. Importantly, we have developed a method for quickly screening newly admitted patients for MRSA.

糖尿病皮肤病变是最常见但最容易被忽视的糖尿病并发症之一，严重影响患者的生存质量，甚至导致糖尿病足的发生。近年来研究提出，糖尿病皮肤病变可在一定程度上预测糖尿病并发症的进展、糖尿病足的发生，因此对于糖尿病皮肤病变的早期诊断及治疗具有重要意义。但目前关于糖尿病皮肤病变的发病机制仍未完全阐明，糖尿病皮肤病变的早期防治也未引起临床上的重视，因此不乏见到因皮肤病变导致严重糖尿病足并最终截肢的病例。该文结合国内外最新进展，从皮肤结构、慢性炎症损伤、皮肤微环境等方面，归纳总结糖尿病患者皮肤病变的病理生理改变，探讨糖尿病皮肤功能障碍潜在的发病机制，阐述皮肤微生态对于糖尿病皮肤病变的影响，为糖尿病皮肤病变的早期诊断和治疗提供理论依据。

Context Imbalance of the skin microbial community could impair skin immune homeostasis and thus trigger skin lesions. Dysbiosis of skin microbiome may be involved in the early pathogenesis of diabetic foot (DF). However, the potential mechanism remains unclear. Objective To investigate the dynamic composition and function of the foot skin microbiome with risk stratification for DF and assess whether dysbiosis of the skin microbiome induces diabetic skin lesions. Methods We enrolled 90 consecutive subjects who were divided into 5 groups based on DF risk stratification: very low, low, moderate, and high risk for ulcers and a healthy control group. Integrated analysis of 16S ribosomal RNA and metagenomic sequencing of cotton swab samples was applied to identify the foot skin microbiome composition and functions in subjects. Then a mouse model of microbiota transplantation was used to evaluate the effects of the skin microbiome on diabetic skin lesions. Results The results demonstrated that, with the progression of diabetic complications, the proportion of gram-negative bacteria in plantar skin increased. At the species level, metagenome sequencing analyses showed Moraxella osloensis to be a representative core strain in the high-risk group. The major microbial metabolites affecting diabetic skin lesions were increased amino acid metabolites, and antibiotic resistance genes in microorganisms were abundant. Skin microbiota from high-risk patients induced more inflammatory cell infiltration, similar to the lipopolysaccharide (LPS)-stimulated response, which was inhibited by Toll-like receptor 4 (TLR4) antagonists. Conclusions The skin microbiome in patients with diabetes undergoes dynamic changes at taxonomic and functional levels with the progression of diabetic complications. The increase in gram-negative bacteria on the skin surface through LPS-TLR4 signal transduction could induce inflammatory response in early diabetic skin lesions.

Introduction Atherosclerosis is the main pathological change in diabetic angiopathy, and vascular inflammation plays an important role in early atherosclerosis. Extracellular heat shock protein 90 (eHsp90) is secreted into the serum and is involved in various physiological and pathophysiological processes. However, the specific mechanism of eHsp90 in early atherosclerosis remains unclear. This study explored the relationship between Hsp90 and diabetic lower extremity arterial disease and investigated the expression of eHsp90 in vascular endothelial cells under environmental stimulation and the function and mechanism of eHsp90α involved in diabetic atherosclerosis.Research design and methods One hundred and three selected patients were divided into three groups: the diabetes mellitus group (n=27), the diabetic lower extremity arterial disease group (n=46), and the diabetic critical limb ischemia group (n=30). The relationships among serum Hsp90, oxidative stress indexes, and patient outcomes and the correlations among the indexes were analyzed. H&E staining and immunohistochemistry were used to observe the vasculature of amputated feet from patients with diabetic foot. An oxidative stress endothelial injury model was established under high glucose in vitro to explore the role of eHsp90 release in atherosclerosis progression.Results The level of serum Hsp90 was upregulated with aggravation of diabetic vascular disease. Hsp90α was correlated with malondialdehyde to some extent and was an independent risk factor in the progression of diabetic vascular disease, with predictive ability. The expression area of Hsp90α was consistent with the area of inflammatory infiltration in the vessel lumen. Vascular endothelial cells were found to increase eHsp90α secretion under stress. Then inhibition of eHsp90α can reduce the degree of cellular inflammation and damage. Endothelial cell-conditioned medium and recombinant human Hsp90α increased monocyte migration via the low-denisity lipoprotein receptor-related protein 1 (LRP1) receptor to promote disease progression.Conclusions eHsp90α plays a critical role in the early inflammatory injury stage of atherosclerosis.Trial registration number NCT04787770.

Macrophages, the main immune cells in the skin, form an innate immune barrier. Under physiological conditions, skin maintains immune barrier function through macrophage phagocytosis and antigen presentation. Parenchymal and stromal cell regeneration plays an important role in skin injury repair and uses macrophage plasticity to influence and stabilize the skin microenvironment. Diabetic skin lesions are the most common diabetes complication and are involved in the early pathophysiology of diabetic foot. Therefore, studying the initial link in diabetic skin lesions is a research hot spot in the early pathogenesis of diabetic foot. Skin inflammation caused by hyperglycaemia, oxidative stress and other injuries is an important feature, but the specific mechanism is unknown. Recent studies have suggested that chronic inflammatory injury is widely involved in a variety of skin diseases, and whether it plays an important role in diabetic skin lesions is unclear. In this review, current research hotspots were combined with the pathogenesis of diabetic skin lesions and analysed from the perspectives of the physiological function of skin macrophages, the impairment of skin macrophages in diabetes, and the mechanism of chronic inflammatory injury in macrophages to provide a theoretical basis for early screening and evaluation of diabetic foot.

The microbiome is greatly significant for immune system development and homeostasis. Dysbiosis in gut microbial composition and function is linked to immune responses and the development of metabolic diseases, including diabetes mellitus (DM). However, skin microbiome changes in diabetic patients and their role in DM are poorly elucidated. In this review, we summarize recent findings about the association between the gut and skin microbiota and DM, highlighting their roles in the proinflammatory status of DM. Moreover, although there is evidence that the connection between the gut and skin causes the same activated innate immune response, additional studies are needed to explore the mechanism. These findings might inform future DM prevention, diagnosis and treatment.

Background: Atherosclerosis is the main pathological change in diabetic angiopathy, and vascular inflammation plays an important role in early atherosclerosis. Heat shock protein 90, a cellular molecular chaperone, was recently determined to be secreted extracellularly, but the specific mechanism remains unclear. This study explored the relationship between Hsp90 and diabetic peripheral artery disease through serological analyses of different groups of diabetic patients and investigated the relationship between extracellular Hsp90α and vascular inflammation at the cellular level. Methods: Seventy-seven selected patients were divided into three groups. The relationships among serum Hsp90, oxidative stress indexes and patient outcomes and the correlations among the indexes were analysed. An oxidative stress endothelial injury model was established under high glucose in vitro to explore the role of eHsp90 release in atherosclerosis progression. Results: Serum Hsp90 and MDA levels tended to increase in different groups with peripheral vascular disease aggravation. Hsp90α was correlated with MDA to some extent and was predictive. In vitro, high glucose and low H 2 O 2 treatment increased extracellular Hsp90 secretion, and endothelial cell conditioned medium and recombinant human Hsp90α increased monocyte migration (P<0.05). Conclusions: Extracellular Hsp90α participates in endothelial cell injury in diabetic vascular disease and initiates the inflammatory response by promoting monocyte migration. Trial registration: NCT04787770, ClinicalTrials.gov, Registered 9 March, 2021 - Prospective registered