Second-degree burns are the most common type of burn in clinical practice and hard to manage. Their treatment requires not only a consideration of the different outcomes that may arise from the dressing changes or surgical therapies themselves but also an evaluation of factors such as the burn site, patient age and burn area. Meanwhile, special attention should be given to the fact that there is no unified standard or specification for the diagnosis, classification, surgical procedure, and infection diagnosis and grading of second-degree burn wounds. This not only poses great challenges to the formulation of clinical treatment plans but also significantly affects the consistency of clinical studies. Moreover, currently, there are relatively few guidelines or expert consensus for the management of second-degree burn wounds, and no comprehensive and systematic guidelines or specifications for the treatment of second-degree burns have been formed. Therefore, we developed the Consensus on the Treatment of Second-Degree Burn Wounds (2024 edition), based on evidence-based medicine and expert opinion. This consensus provides specific recommendations on prehospital first aid, nonsurgical treatment, surgical treatment and infection treatment for second-degree burns. The current consensus generated a total of 58 recommendations, aiming to form a standardized clinical treatment plan.
Background: Hypertrophic scar (HS) is a common fibroproliferative skin disease that currently has no truly effective therapy. Given the importance of phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) in hypertrophic scar formation, the development of therapeutic strategies for endogenous inhibitors against PIK3CA is of great interest. Here, we explored the molecular mechanisms underlying the protective effects of miR-203a-3p (PIK3CA inhibitor) against excessive scar.
Methods: Bioinformatic analysis, immunohistochemistry, immunofluorescence, miRNA screening and fluorescence in situ hybridization assays were used to identify the possible pathways and target molecules mediating HS formation. A series of in vitro and in vivo experiments were used to clarify the role of PIK3CA and miR-203a-3p in HS. Mechanistically, transcriptomic sequencing, immunoblotting, dual-luciferase assay and rescue experiments were executed.
Results: Herein, we found that PIK3CA and the phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR pathway were upregulated in scar tissues and positively correlated with fibrosis. We then identified miR-203a-3p as the most suitable endogenous inhibitor of PIK3CA. miR-203a-3p suppressed the proliferation, migration, collagen synthesis and contractility as well as the transdifferentiation of fibroblasts into myofibroblasts in vitro, and improved the morphology and histology of scars in vivo. Mechanistically, miR-203a-3p attenuated fibrosis by inactivating the PI3K/AKT/mTOR pathway by directly targeting PIK3CA.
Conclusions: PIK3CA and the PI3K/AKT/mTOR pathway are actively involved in scar fibrosis and miR-203a-3p might serve as a potential strategy for hypertrophic scar therapy through targeting PIK3CA and inactivating the PI3K/AKT/mTOR pathway.
Metabolic reprogramming refers to the ability of a cell to alter its metabolism in response to different stimuli and forms of pressure. It helps cells resist external stress and provides them with new functions. Skin wound healing involves the metabolic reprogramming of nutrients, such as glucose, lipids, and amino acids, which play vital roles in the proliferation, differentiation, and migration of multiple cell types. During the glucose metabolic process in wounds, glucose transporters and key enzymes cause elevated metabolite levels. Glucose-mediated oxidative stress drives the proinflammatory response and promotes wound healing. Reprogramming lipid metabolism increases the number of fibroblasts and decreases the number of macrophages. It enhances local neovascularization and improves fibrin stability to promote extracellular matrix remodelling, accelerates wound healing, and reduces scar formation. Reprogramming amino acid metabolism affects wound re-epithelialization, collagen deposition, and angiogenesis. However, comprehensive reviews on the role of metabolic reprogramming in skin wound healing are lacking. Therefore, we have systematically reviewed the metabolic reprogramming of glucose, lipids, and amino acids during skin wound healing. Notably, we identified their targets with potential therapeutic value and elucidated their mechanisms of action.
Background: The gut microbiota is a complex ecosystem that plays a critical role in human health and disease. However, the relationship between gut microbiota and intestinal damage caused by burns is not well understood. The intestinal mucus layer is crucial for maintaining intestinal homeostasis and providing a physiological barrier against bacterial invasion. This study aims to investigate the impact of gut microbiota on the synthesis and degradation of intestinal mucus after burns and explore potential therapeutic targets for burn injury.
Methods: A modified histopathological grading system was employed to investigate the effects of burn injury on colon tissue and the intestinal mucus barrier in mice. Subsequently, 16S ribosomal RNA sequencing was used to analyze alterations in the gut microbiota at days 1-10 post-burn. Based on this, metagenomic sequencing was conducted on samples collected at days 1, 5 and 10 to investigate changes in mucus-related microbiota and explore potential underlying mechanisms.
Results: Our findings showed that the mucus barrier was disrupted and that bacterial translocation occurred on day 3 following burn injury in mice. Moreover, the gut microbiota in mice was significantly disrupted from days 1 to 3 following burn injury, but gradually recovered to normal as the disease progressed. Specifically, there was a marked increase in the abundance of symbiotic and pathogenic bacteria associated with mucin degradation on day 1 after burns, but the abundance returned to normal on day 5. Conversely, the abundance of probiotic bacteria associated with mucin synthesis changed in the opposite direction. Further analysis revealed that after a burn injury, bacteria capable of degrading mucus may utilize glycoside hydrolases, flagella and internalins to break down the mucus layer, while bacteria that synthesize mucus may help restore the mucus layer by promoting the production of short-chain fatty acids.
Conclusions: Burn injury leads to disruption of colonic mucus barrier and dysbiosis of gut microbiota. Some commensal and pathogenic bacteria may participate in mucin degradation via glycoside hydrolases, flagella, internalins, etc. Probiotics may provide short-chain fatty acids (particularly butyrate) as an energy source for stressed intestinal epithelial cells, promote mucin synthesis and accelerate repair of mucus layer.