Synergistic Effects of LPS and MSU on NF-κB/NLRP3-mediated Inflammation in Fibroblast Cells

Inflammation is a biological response implicated in various chronic diseases, including arthritis, fibrosis, and autoimmune disorders. Human dermal fibroblasts (HDF) play a significant role in inflammatory processes, making them a valuable model for studying inflammation-related mechanisms. This study investigates the inflammatory response of HDF cells upon stimulation with lipopolysaccharide (LPS) and monosodium urate (MSU) crystals, which mimic pathogen- and danger-associated molecular patterns, respectively. Cell viability assays demonstrated that MSU crystals did not significantly reduce fibroblast viability from 50 to 250 µg/ml concentration range. Nitric oxide and reactive oxygen species assays revealed a significant increase in oxidative stress (131.36 ± 3.14 RFI) and inflammatory mediator (43.08 ± 1.18 µM) following 1 µg/ml LPS and 250 µg/ml MSU co-treatment. Western blot analysis confirmed 3.44 ± 0.18-fold upregulation of NF-κB p65 phosphorylation and increased (2.77 ± 0.17 fold) expression of nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain containing 3 (NLRP3) and ASC, indicating inflammasome activation. The results suggest that LPS and MSU induce a robust inflammatory response in HDF cells, making them a suitable in vitro model to study fibroblast-mediated inflammation. These findings provide a valuable tool for investigating inflammatory pathways and testing potential anti-inflammatory drugs. The model can be utilized for screening pharmacological agents targeting nuclear factor kappa B and NLRP3 pathways, thereby aiding in the development of therapies for inflammatory and fibrotic diseases. However, further pharmacological validation using known inhibitors is necessary to confirm its specificity and reliability for drug screening applications.