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Several diseases are characterized by chronic inflammation, a condition frequently associated with angiogenesis and fibrogenesis that account for the development of granulation tissue. Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a crucial modulator of intracellular prosurvival signaling pathways and is implicated in the pathogenesis of inflammatory process. In this study, we have investigated the role of NF-κB in the angiogenic and fibrogenic response induced by λ-carrageenin in a rat model of chronic inflammation at 1, 3, and 5 days. The subcutaneous implant of λ-carrageenin-soaked sponges in rat induced a time-related increase of granulation tissue formation accompanied by intense neovascularization. These λ-carrageenin-induced changes were significantly reduced by coinjection of wild-type oligodeoxynucleotide (WT ODN) decoy to NF-κB. Molecular, morphological, and ultrastructural analysis performed on whole granulation tissue demonstrated: (1) inhibition of NF-κB/DNA binding activity; (2) downregulation of cyclooxygenase-2, matrix metalloproteinase-9, tumor necrosis factor-α, and vascular endothelial growth factor; (3) upregulation of thrombospondin (TSP)-1 at 1 day and TSP-2 at 5 days; and (4) increase in Bax to Bcl-2 ratio. Our findings show that the blockade of NF-κB activation by WT ODN decoy prevents the development of granulation tissue induced by λ-carrageenin-soaked sponge implant upregulating Bax as well as TSP-1 and TSP-2 expression. [ABSTRACT FROM AUTHOR]

Chronic inflammation is often associated with granuloma formation that is a hallmark of many human diseases. The transcription factor nuclear factor-kappa B (NF-κB) plays a central role in this process by regulating the expression of several pro-inflammatory genes. Cannabinoids (CBs) from Cannabis sativa L. exert a large number of biological effects including anti-inflammatory and anti-angiogenic effects. In this study, we investigated the role of CBs on granuloma formation induced by λ-carrageenin-soaked sponge implant in rat. Our results show that local administration of WIN 55,212-2, a CB1/CB2 agonist, given daily or at time of implantation significantly decreased weight and neo-angiogenesis in granuloma tissue and inhibited nuclear factor-kappa B (NF-κB)/DNA binding that was associated with a reduced inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), tumor necrosis factor alpha (TNF-α), and vascular endothelial growth factor (VEGF) messenger RNA (mRNA) and protein expression. Also, arachidonyl-2-chloroethylamide (ACEA), a CB1 selective agonist, and JWH-015, a CB2 selective agonist, exhibited the same effects that were reversed by SR141716-A and SR144528, respectively, CB1 and CB2 selective antagonists. These results indicate that CBs given locally may represent a potential therapeutic tool in controlling chronic inflammation avoiding psychotropic effects. [ABSTRACT FROM AUTHOR]