The study of the fungal communities of the skin constitutes a pivotal component of skin microbiome research. Within these communities, the genus Malassezia stands out as a major constituent, representing 50% to 80% of the total fungal colonization on the skin of healthy individuals. The excessive growth or metabolic irregularities of this genus are intimately connected with the onset of various skin disorders that are intrinsically linked to its lipid-dependent nature. Cutaneous lipid metabolism is indispensable for maintaining the skin barrier function and skin health. Malassezia possesses the ability to encode multiple lipase genes, and the secretion of these lipases plays a pivotal role in the survival strategies of the fungi. This review explores recent advances in the ecological niche of Malassezia in skin microecological homeostasis, its mechanism of disrupting skin lipids through catabolic metabolites, and the relationship between this disruption of the skin lipid barrier and skin diseases. This review offers a reference for future research on the mechanisms by which Malassezia affects lipid metabolism and provides a theoretical foundation for the development of innovative therapeutic approaches for dermatological conditions.

The accumulation of advanced glycation end products (AGEs) plays a crucial role in chronic inflammation and delayed wound healing in individuals with diabetes. In this context, fibronectin has been identified as a crucial protein that promotes the differentiation of human periodontal ligament stem cells (hPDLSCs) into myofibroblasts, which play a vital role in the repair of diabetic skin ulcers. This process is intimately associated with the integrin β1 receptor and the NF-κB signaling pathway, both crucial for cellular responses to fibronectin. To validate our hypothesis, we expressed rhFN1024, a recombinant protein containing the integrin β1 affinity-binding domain from human fibronectin segments 12–14. This protein was used to formulate a hydrogel for hPDLSCs. rhFN1024's binding affinity to integrin β1 was confirmed by molecular docking and the cellular thermal shift assay (CETSA). We developed sh-ITGB1-hPDLSCs with stable ITGB1 knockdown using shRNA-ITGB1 and compared their proliferation, migration and adhesion to wild-type hPDLSCs. Morphological changes were observed via SEM, and α-SMA expression levels were measured in AGEs-damaged hPDLSCs. We created full-thickness wound models in diabetic mice to assess pharmacodynamics. The study showed that rhFN1024 stimulated hPDLSCs differentiation into myofibroblasts by boosting ITGB1 expression. rhFN1024 also reduced AGEs' negative effects on hPDLSCs, as seen through SEM analysis and α-SMA levels. In full-thickness wound models, hPDLSCs and rhFN1024 accelerated re-epithelialization and collagen synthesis. rhFN1024 is proposed to interact with the ITGB1 receptor on hPDLSCs, activating the NF-κB pathway to neutralize AGEs-induced pro-inflammatory cytokines. This study suggests rhFN1024 as a potential biomedical material for tissue repair.

To investigate the potential of recombinant protein disulfide isomerase (PDI) as a raw material for skin-repair cosmetics, an engineered PDI-producing strain was constructed using the Pichia pastoris X33 expression system. The target protein was obtained through methanol-induced expression and anion-exchange chromatography purification, and its cytotoxicity and pro-adhesive effects on human skin fibroblasts (HSFs) were evaluated. The results showed that the purified recombinant PDI protein had an apparent molecular weight of approximately 55.7 kDa. Treatment with 0.04–5 µmol/L recombinant PDI for 24 h did not affect cell viability. On culture surfaces coated with 62.5 nmol/L recombinant human fibronectin (rhFN) or 31.25 nmol/L recombinant human collagen (rhC), the addition of 250 nmol/L recombinant PDI increased the HSF adhesion area ratio to approximately 2.1-fold that of the rhFN-alone group (p < 0.0001) and 1.9-fold that of the rhC-alone group (p < 0.0001). Collectively, the recombinant PDI protein exhibits good biocompatibility and pro-adhesive activity, demonstrating its potential as a candidate raw material for skin-repair cosmetics.