Inducible nitric oxide synthase links NF-κB to PGE(2 )in polyunsaturated fatty acid altered fibroblast in-vitro wound healing

BACKGROUND: This study investigated mechanisms of altered fibroblast collagen production induced by polyunsaturated fatty acids. 3T3-Swiss fibroblasts were grown in medium containing either eicosapentaenoic or arachidonic acid. The effects of nuclear factor-kappaB activation by lipopolysaccharide on inducible nitric oxide synthase, nitric oxide, prostaglandin E(2), collagen production, and in-vitro wound healing were studied. RESULTS: Eicosapentaenoic acid treated cells produced less prostaglandin E(2 )but had increased inducible nitric oxide synthase expression, nitric oxide production, collagen formation, and recoverage area during in-vitro wound healing than cells treated with arachidonic acid. Activation of nuclear factor-kappaB with lipopolysaccharide increased inducible nitric oxide synthase expression, the production of nitric oxide, prostaglandin E(2), collagen, and the in-vitro wound recoverage area. The nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester, decreased lipopolysaccharide-induced nitric oxide, but the amount of nitric oxide was greater in eicosapentaenoic acid treated cells. N(G)-nitro-L-arginine methyl ester plus lipopolysaccharide treatment increased collagen production and cellular recoverage area while treatment with N(G)-nitro-L-arginine methyl ester alone decreased it in wounded fibroblasts. CONCLUSION: The activation of the NF-κB pathway and PGE(2 )can be linked by the cross-talk of iNOS and NO in the PUFA altered fibroblast collagen production and wound healing. Additional studies are needed to determine how polyunsaturated fatty acids can be used as adjuvants in combination with other treatments (i.e, drugs) to design therapies to either enhance healthy collagen production or inhibit production and reduce fibrosis.