[Evaluation of the skin barrier repair function and anti-inflammatory activity of recombinant mussel mucin Mfp151].

Inflammation is a primary driver of skin ageing. Mussel mucin, a naturally occurring anti-inflammatory protein, suffers from inefficient extraction from its natural source. To overcome the yield limitation of natural sources and to verify the biological activity of the recombinant protein, this study employed synthetic biology techniques to efficiently produce and purify the recombinant mussel mucin Mfp151 and subsequently evaluated its anti-inflammatory and skin barrier repair functions. Using human immortalized keratinocytes (HaCaT), human foreskin fibroblasts (HFF-1), and human monocyte leukemia cells (THP-1) as models, we assessed the skin-repairing, antioxidant, and anti-inflammatory effects of Mfp151 via the CCK-8 assay, qPCR, transmembrane resistance measurement, scratch assay, ELISA, and free radical scavenging assays. In vivo validation was conducted with a zebrafish sunburn model. The results demonstrated that Mfp151 significantly promoted cell proliferation (80 μg/mL treatment increased HaCaT cell proliferation by approximately 32%) and migration, while upregulating the expression of key skin barrier genes IVL, OVOL1, and AQP3 by 2.14-3.88 folds. Mfp151 effectively scavenged DPPH and ABTS free radicals while enhancing cellular antioxidant capacity by activating the Nrf2 pathway. Regarding anti-inflammatory effects, Mfp151 significantly suppressed lipopolysaccharide-induced production of pro-inflammatory factors IL-6, TNF-α, and IL-1β (80 μg/mL treatment reduced expression levels to 59.87%-79.12% of that in the model group), while significantly downregulating the expression of key inflammatory mediators COX-2 and iNOS and their downstream product PGE2 (80 μg/mL treatment reduced COX-2, iNOS expression and PGE2 secretion to 48.91%-67.30% those in the model group.) Zebrafish experiments confirmed the significant promotion of Mfp151 on caudal fin repair following sunburn. The data indicate that the recombinant Mfp151 obtained through synthetic biology techniques possesses skin-repairing functions alongside antioxidant and anti-inflammatory activities, thus demonstrating promising application prospects in fields such as anti-ageing cosmetic ingredients and wound dressings.