Project description:Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus, which causes great health damage and economic burden to patients. The pathogenesis of DFU is not fully understood.We screened wound healing-related genes using bioinformatics analysis, and full-thickness skin injury mice model and cellular assays were used to explore the role of target genes in diabetic wound healing. SFRP2 was identified as a wound healing-related gene, and the expression of SFRP2 is associated with immune cell infiltration in DFU. In vivo study showed that suppression of SFRP2 delayed the wound healing process of diabetic mice, impeded angiogenesis and matrix remodeling, and increased macrophage infiltration in wound tissues. In addition, suppression of SFRP2 enhanced M1 polarization in both the early and later stage of wound healing, and decreased M2 polarization in the later stage, which impeded the transition of M1 to M2 polarization of wound healing. Moreover, suppression of SFRP2 affected the transcriptome signatures-related to inflammatory response and energy metabolism at the early stage of wound healing. Extracellular flux analysis (EFA) showed that suppression of SFRP2 decreased mitochondrial energy metabolism and increased glycolysis in injury-related macrophages. Furthermore, suppression of SFRP2 inhibited transcriptome signaturesrelated to carbohydrate metabolism, lipid metabolism and amino acid metabolism, which consists the three main components of energy metabolism of macrophages. In conclusions, SFRP2 may function as a wound healing-related gene in DFU, and suppression of SFRP2 impaired diabetic wound healing by compromising the M1-to-M2 transition of macrophages and modulating the balance between mitochondrial energy metabolism and glycolysis.
Project description:Diabetic foot ulcer (DFU) is a serious complication of diabetes mellitus, which causes great health damage and economic burden to patients. The pathogenesis of DFU is not fully understood.We screened wound healing-related genes using bioinformatics analysis, and full-thickness skin injury mice model and cellular assays were used to explore the role of target genes in diabetic wound healing. SFRP2 was identified as a wound healing-related gene, and the expression of SFRP2 is associated with immune cell infiltration in DFU. In vivo study showed that suppression of SFRP2 delayed the wound healing process of diabetic mice, impeded angiogenesis and matrix remodeling, and increased macrophage infiltration in wound tissues. In addition, suppression of SFRP2 enhanced M1 polarization in both the early and later stage of wound healing, and decreased M2 polarization in the later stage, which impeded the transition of M1 to M2 polarization of wound healing. Moreover, suppression of SFRP2 affected the transcriptome signatures-related to inflammatory response and energy metabolism at the early stage of wound healing. Extracellular flux analysis (EFA) showed that suppression of SFRP2 decreased mitochondrial energy metabolism and increased glycolysis in injury-related macrophages. Furthermore, suppression of SFRP2 inhibited transcriptome signaturesrelated to carbohydrate metabolism, lipid metabolism and amino acid metabolism, which consists the three main components of energy metabolism of macrophages. In conclusions, SFRP2 may function as a wound healing-related gene in DFU, and suppression of SFRP2 impaired diabetic wound healing by compromising the M1-to-M2 transition of macrophages and modulating the balance between mitochondrial energy metabolism and glycolysis.
Project description:Severe angiopathy is a major driver for diabetes associated secondary complications. Knowledge on underlying mechanisms essential for advanced therapies to attenuate these pathologies is limited. Injection of ABCB5+ stromal precursors (SPs) at the edge of non-healing diabetic wounds in a murine db/db model, closely mirroring human type II diabetes, profoundly accelerates wound closure. Strikingly, enhanced angiogenesis was substantially enforced by the release of the ribonuclease angiogenin from ABCB5+ SPs. This compensates for the profoundly reduced angiogenin expression in non-treated murine and human chronic diabetic wounds. Silencing of angiogenin in ABCB5+ SPs prior to injection significantly reduced angiogenesis, reduced numbers of M2 macrophages and delayed wound closure in diabetic db/db mice implying an unprecedented key role for angiogenin in tissue regeneration in diabetes. These data hold significant promise for further refining SPs-based therapies of non-healing diabetic foot ulcers and other pathologies with impaired angiogenesis.
Project description:Global alterations of the early wound healing program by transcriptomics at a skin-wide level by deletion of HIF-1α in wound-infiltrating NK cells.
Project description:Objective This study aims to investigate the effects of electroacupuncture on chronic wounds associated with diabetes, particularly focusing on its potential mechanisms for enhancing wound healing through the promotion of angiogenesis. While acupuncture has been shown to improve wound healing by enhancing blood supply and vascular regeneration, the therapeutic effects of electroacupuncture in diabetic chronic wounds have not been sufficiently addressed. Methods A diabetic skin ulcer mouse model was established for this study. The effects of electroacupuncture on wound healing were assessed through evaluation of skin healing rates, ELISA assays, and histopathological analyses. Additionally, a tissue transparency three-dimensional imaging technique was utilized to establish a vascular model of wounds on day 10, clarifying the impact of electroacupuncture on angiogenesis during the proliferation phase in diabetic mouse skin wound models. Proteomic analysis was conducted to identify potential targets and mechanisms by which electroacupuncture regulates diabetic wound healing, further validated by immunohistochemistry (IHC) and Western blotting (WB). Results The experimental results demonstrated that electroacupuncture significantly promotes wound healing in diabetic mice, reduces the levels of the pro-inflammatory cytokine IL-6 during the inflammatory phase, decreases inflammatory cell infiltration, and increases collagen synthesis. Proteomic analysis indicated that electroacupuncture may facilitate diabetic wound healing by enhancing endothelial cell proliferation and modulating angiogenic morphogenesis. Furthermore, electroacupuncture was shown to upregulate the expression of CXCL12 and its co-localization with CXCR4, while promoting the phosphorylation of PI3K and AKT, thereby enhancing the expression of VEGF and improving angiogenesis. Three-dimensional tissue transparency imaging provided comprehensive visual evidence of the angiogenic effects induced by electroacupuncture. Conclusion The findings of this study suggest that electroacupuncture activates the PI3K/AKT signaling pathway through the CXCL12/CXCR4 axis to promote vascular regeneration, thereby improving the healing process of diabetic skin wounds in mice.
Project description:Application of autologous adipose-derived stem cells (ASC) for diabetic chronic wounds has become an emerging treatment option. However, ASCs from diabetic individuals showed impaired cell function and suboptimal wound healing effects. We proposed that adopting a low glucose level in the culture medium for diabetic ASCs may restore their pro-healing capabilities. ASCs from diabetic humans and mice were retrieved and cultured in high-glucose (HG, 4.5 g/L) or low-glucose (LG, 1.0 g/L) conditions. Cell characteristics and functions were investigated in vitro. Moreover, we applied diabetic murine ASCs cultured in HG or LG condition to a wound healing model in diabetic mice to compare their healing capabilities in vivo. Human ASCs exhibited decreased cell proliferation and migration with enhanced senescence when cultured in HG condition in vitro. Similar findings were noted in ASCs derived from diabetic mice. The inferior cellular functions could be partially recovered when they were cultured in LG condition. In the animal study, wounds healed faster when treated with HG or LG-cultured diabetic ASCs relative to the control group. Moreover, higher collagen density, more angiogenesis and cellular retention of applied ASCs were found in wound tissues treated with diabetic ASCs cultured in LG condition. In line with the literature, our study showed that a diabetic milieu exerts an adverse effect on ASCs. Adopting LG culture condition is a simple and effective approach to enhance the wound healing capabilities of diabetic ASCs, which is valuable for the clinical application of autologous ASCs from diabetic patients.
Project description:Impaired skin wound healing is a significant global health issue, especially among the elderly. Wound healing is a well-orchestrated process involving the sequential phases of inflammation, proliferation, and tissue remodeling. Although wound healing is a highly dynamic and energy-requiring process, the role of metabolism remains largely unexplored. By combining transcriptomics and metabolomics of human skin biopsy samples, we mapped the core bioenergetic and metabolic changes in normal acute as well as chronic wounds in elderly subjects. We found upregulation of glycolysis, the tricarboxylic acid cycle, glutaminolysis, and β-oxidation in the later stages of acute wound healing and in chronic wounds. To ascertain the role of these metabolic pathways on wound healing, we targeted each pathway in a wound healing assay as well as in a human skin explant model using metabolic inhibitors and stimulants. Enhancement or inhibition of glycolysis and, to a lesser extent, glutaminolysis had a far greater impact on wound healing than similar manipulations of oxidative phosphorylation and fatty acid β-oxidation. These findings increase the understanding of wound metabolism and identify glycolysis and glutaminolysis as potential targets for therapeutic intervention.
Project description:Impaired healing of diabetic wounds causes significant morbidity and mortality. This study aimed to identify novel mechanisms of diabetic wound healing defects and test a therapeutic intervention using diabetic mouse and pig models. We found Smad7 transgene expression in mouse epidermis promoting wound healing in diabetic db/db mice, with reductions in obesity and blood glucose. To isolate effects of Smad7 on wounds, we created a Smad7-based biologic (Tat-PYC-Smad7) that penetrates wound cells. Topical application of Tat-PYC-Smad7 to diabetic pig and mouse wounds accelerated healing compared to controls. RNAseq analysis of mouse wound samples showed reduced TGFβ/NFκB signaling, leading to faster re-epithelialization and better extracellular matrix remodeling. Tat-PYC-Smad7 also attenuated neutrophil degranulation and NETosis by blocking histone 3 citrullination and inhibiting myeloperoxidase activities. Our study reveals that Tat-PYC-Smad7 promotes diabetic wound healing by targeting keratinocytes and neutrophils, providing insight into cellular mechanisms of diabetic wound healing defects targetable by Smad7-based therapy.
Project description:MicroRNAs are powerful gene expression regulators, but their corneal repertoire and potential changes in corneal diseases remain unknown. Our purpose was to identify miRNAs altered in the human diabetic cornea by microarray analysis, and to examine their effects on wound healing in cultured telomerase-immortalized human corneal epithelial cells (HCEC) in vitro. Using microarrays, 29 miRNAs were identified as differentially expressed in diabetic samples. Two miRNA candidates showing the highest fold increased in expression in the diabetic cornea were confirmed by Q-PCR and further characterized. HCEC transfection with h-miR-146a or h-miR-424 significantly retarded wound closure, but their respective antagomirs significantly enhanced wound healing vs. controls. Cells treated with h-miR-146a or h-miR-424 had decreased p-p38 and p-EGFR staining, but these increased over control levels close to the wound edge upon antagomir treatment. In conclusion, several miRNAs with increased expression in human diabetic central corneas were found. Two such miRNAs inhibited cultured corneal epithelial cell wound healing. Dysregulation of miRNA expression in human diabetic cornea may be an important mediator of abnormal wound healing. Total RNA was extracted from age-matched human autopsy normal (n=6) and diabetic (n=6) central corneas, Flash Tag end-labeled, and hybridized to Affymetrix® GeneChip® miRNA Arrays. Select miRNAs associated with diabetic cornea were validated by quantitative RT-PCR (Q-PCR) and by in situ hybridization (ISH) in independent samples.