Unraveling the biological potential of skin fibroblast: responses to TNF-α, highlighting intracellular signaling pathways and secretome

Objective

In this study, we examined the molecular response of human skin fibroblasts to an inflammatory cytokine to evaluate their suitability as models for immunopathology research.

Methods

Skin fibroblasts were stimulated with tumour necrosis factor (TNF)-α, and the transcriptome was profiled via RNA-Seq. The differentially expressed genes were screened to predict immunological pathways and interactions. The cytokines and signaling pathways were validated at protein level. Similarly to immune cells, TNF-α caused transcriptional and transductional changes in fibroblasts.

Results

Functional analysis revealed significant enrichment of TNF-α signaling and cell chemotaxis (normalized enrichment score = 2.59 and 3.42). We also detected enrichment of nuclear factor kappa B (NF-κB) target genes and NF-kB activation, confirmed by complete protein degradation of its inhibitor IκBa (p = 0.0019). The MAPK/ERK and p38 MAPK pathways were also activated. Finally, we observed significant secretion of proinflammatory cytokines and chemokines, such as interleukin 6 (p = 0.02), CXCL8 (p = 0.027), CCL2 (p = 0.028) and CCL5 (p = 0.016).

Conclusion

This study advances the biological understanding of skin fibroblast responses to TNF-α, revealing their intracellular pathways and secretome. It discloses techniques for leveraging fibroblasts' potential as in vitro models to identify inflammatory drivers, particularly when alternative models are inaccessible.