Editorial [Hot Topic: Pathophysiology and Current Therapeutics of Inflammatory Diseases (Guest Editor: Fadia R. Homaidan)]

Inflammation is the physiological protective response of the organism to stimuli ranging from a transient, self-limited and localized response to a complex, sustained response involving the whole organism. Inflammatory processes are characterized by the stimulation of humoral and cellular signaling systems and, as a result, mediators of inflammation, such as interleukins-1, and-6 and tumor necrosis factor-α are expressed and released at the site of injury by diverse cell types. An increase in the levels of inflammatory mediators can result in alterations in microvascular tone and permeability, in addition to activating pathways for the synthesis of eicosanoids, such as prostaglandins (PGs) and leukotrienes (LTs), which are lipid mediators involved in the regulation of the complex inflammatory reaction. PGs, such as PGE2 and prostacyclin (PGI2), induce vasodilation and edema development, and contribute to hyperalgesia at the site of inflammation. Additionally, fatty acid peroxides and LTs cause an increase in local permeability and are potent neutrophil chemoattractants. The study of the inflammatory process provides opportunities for impacting many diseases, including allergies, asthma, arthritis and autoimmune diseases, as well as cardiovascular, neuromuscular and gastrointestinal diseases. In this special edition of AIAA the pathophysiology of many inflammatory disorders are discussed. Recent advances in the cell and molecular biology of inflammation and the capacity for manipulation of gene expression in injured tissues now facilitate and enhance our knowledge and provide novel avenues to unravel the complex pathogenesis of inflammatory diseases. This will guide our efforts to develop new approaches toward diagnosis, prevention and therapy. The themes covered in this edition include a discussion on atherosclerosis which, as an inflammatory disease, contributes to the pathological process that culminates in coronary artery disease. Recently, it has been shown that inflammation is involved in plaque formation, progression and rupture. At the molecular level nuclear factor kappa-B (NF-kB) activation has been implicated in lesion formation and progression. In their manuscript “Inflammation in Atherosclerosis: a New Therapeutic Target”, Skouri and co-workers discuss the mechanism of action of NF-kB activation and the effect of inhibitors of NF-kB activity on the inflammatory processes. Mourad in “Designing and Testing New Therapeutic Modalities for Treatment of Inflammatory Bowel Disease: Role of Experimental Animal Models“, discusses the pathogenesis of inflammatory bowel disease (IBD) and highlights potential targets for therapeutic intervention. The author presents insights on the use of experimental models to understand the pathogenesis and to define rational cell and molecular targets, at multiple levels, for IBD therapy. Available therapies for the treatment of inflammatory bowel disease are not satisfactory and are only effective in around 50% of the patients. In the following manuscript, “Biologic and Novel Therapy of the Inflammatory Bowel Diseases“, Makrauer and Burakoff focus their review on new experimental biologic therapies, their actions and potential benefits. Inhibitors of inflammatory cytokines, such as anti-tumor necrosis factor agents (anti-TNF); antagonists of TNF; anti-interleukin-12; antiinterleukin- 2 receptor; inhibitors of lymphocyte trafficking; and anti-adhesion molecules, as potential therapeutic agents is highlighted. Haddad, Saade' and Safieh-Garabedian in “Thymulin: an Emerging Anti-Inflammatory Molecule“ discuss thymulin, an endogenous neuroendocrine hormone with immunoregulatory actions, which has recently been shown to possess antinociceptive effects in hyperalgesia and in pain of neurogenic origin. The authors also describe the anti-inflammatory actions of thymulin in autoimmune diseases, rheumatoid arthritis and in peripheral and/or central nervous system inflammation. Finally, Arayssi and Hamdan in “Update on the Therapy of Behçet's Disease“, review Behçet's Disease which is a chronic inflammatory systemic disorder that remains elusive to therapy. The authors describe the pathogenesis, diagnosis and clinical manifestations of the disease and describe the many therapies that are available or are under development, their mechanism of action and their efficacy.