RESUMO
Alcoholic liver disease (ALD) is a chronic liver disease in which the internal liver tissues are inflammation damaged caused by long-term excessive drinking. Direct or indirect induction of hepatic inflammatory response by ethanol and its derivatives in the metabolic process may be an important mechanism of ALD, but the underlying cellular and molecular mechanisms of this process are still unclear. Recent study found that interleukin-6 (IL-6) response to ethanol mediated inflammation of the liver cells with dual role. It is involved in an inflammatory process that drives alcohol damage, activate cell apoptosis signaling pathways to stimulate macrophage and lymphocyte acute reactive protein synthesis aggravate the inflammatory response, and can lead to liver cell regeneration, increase anti-inflammatory cytokine levels play anti-inflammatory function to improve the degree of liver injury, and exercise stress can cause muscle source sex IL-6 temporary increased significantly, change the liver oxidation-inflammatory state. Then the body is kept in the adaptive state of long-term anti-inflammation to prevent the inflammatory damage of liver cells. Based on deepening the understanding of ALD inflammation pathological mechanism at the same time, the review on alcoholic liver cell inflammation related factor change and the IL-6 regulation pathway, considering the clinical use of IL-6 joint inflammatory factor pathway of targeted therapy is expected to be a novel therapy, the feasibility for laboratory screening of inflammatory related ALD drug intervention, for the prevention of alcoholic liver disease and treatment to provide new targets and train of thought.
RESUMO
OBJECTIVE: The objective of this study was to determine the effect of nonspecific phosphodiesterase inhibition on transcription factor activation and tumor necrosis factor-alpha (TNF-a) production in lipopolysaccharide (LPS)-stimulated human mononuclear cells. INTRODUCTION: The production of TNF-a following LPS stimulation is one of the key steps in bacterial sepsis and inflammation. The mechanism by which phosphodiesterase inhibition alters TNF-a production in the presence of LPS remains unclear. METHODS: Human mononuclear cells were stimulated with LPS (1 µg/mL), in the presence and absence of Pentoxifylline (PTX; 20 mM), a nonspecific phosphodiesterase inhibitor. Western blotting of phosphorylated cytoplasmic I-kBa, nuclear factor-kB p65 (NF-kB), and nuclear cAMP-response element binding protein (CREB) was performed. DNA binding of NF-kB and CREB was verified by electrophoretic mobility shift assay. TNF-a levels were determined in the supernatant of stimulated cells in the presence and absence Protein kinase A inhibition by an enzyme-linked immunosorbent assay (ELISA). RESULTS: PTX was demonstrated to significantly reduce cytoplasmic I-kBa phosphorylation, nuclear p65 phosphorylation, and the DNA binding activity of NF-kB. In contrast, PTX markedly enhanced the phosphorylation and DNA binding activity of CREB. Cells concomitantly treated with PTX and LPS secreted similar levels of TNF-a in the presence and absence Protein kinase A inhibition. DISCUSSION: The increased level of cAMP that results from phosphodiesterase inhibition affects cytoplasmic and nuclear events, resulting in the attenuation of NF-kB and the activation of CREB transcriptional DNA binding through pathways that are partially Protein kinase A-independent. CONCLUSION: PTX-mediated phosphodiesterase inhibition occurs partially through a Protein kinase A-independent pathway and may serve as a useful tool in the attenuation of LPS-induced inflammation.