Faculty Bibliography

Gout is the most common inflammatory arthritis in the United States, with more than three million sufferers. Management of gout has changed relatively little in the past 50 years, despite the fact that many gout patients have contraindications to one or more currently available gout therapies. However, recent insights into gout pathophysiology suggest that time is ripe for a change. This article reviews recent updates in the management of gout, including new insights into dietary management that may permit better control of hyuperuricemia. Also reviewed are the biological and clinical data behind newly-developed drugs for gout that are likely to receive serious consideration for FDA approval, and clinical use, in the foreseeable future

Traditional NSAIDs and some cyclooxygenase (COX)-2 inhibitors used to treat persons with osteoarthritis (OA) have adverse effects. However, traditional NSAIDs remain first-line therapy for some patients. The toxicities (eg, renal and GI effects) mostly are the result of COX inhibition. The ideal NSAID would inhibit COX-2 while sparing COX-1. The mechanisms for increased COX-2 cardiovascular toxicity remain less than fully understood. Several conservative strategies may help physicians use these agents effectively and safely. OA therapies under investigation (eg, inhibition of prostaglandin E synthases and disease-modifying osteoarthritis drugs) may render NSAIDs and COX-2 inhibitors obsolete

Both selective cyclooxygenase (COX)-2 inhibitors and non-steroidal anti-inflammatory drugs (NSAIDs) have been beneficial pharmacological agents for many patients suffering from arthritis pain and inflammation. However, selective COX-2 inhibitors and traditional NSAIDs are both associated with heightened risk of myocardial infarction. Possible pro-atherogenic mechanisms of these inhibitors have been suggested, including an imbalance in prostanoid production leaving the pro-aggregatory prostaglandins unopposed, but the precise mechanisms involved have not been elucidated. We explored the possibility that downregulation of proteins involved in reverse cholesterol transport away from atheromatous plaques contributes to increased atherogenesis associated with COX inhibition. The reverse cholesterol transport proteins cholesterol 27-hydroxylase and ATP-binding cassette transporter A1 (ABCA1) export cholesterol from macrophages. When mechanisms to process lipid load are inadequate, uncontrolled cholesterol deposition in macrophages transforms them into foam cells, a key element of atheromatous plaques. We showed that in cultured THP-1 human monocytes/macrophages, inhibition of COX-1, COX-2, or both reduced expression of 27-hydroxylase and ABCA1 message (real-time reverse transcription-polymerase chain reaction) and protein (immunoblot). The selective COX-2 inhibitor N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide (NS398) significantly reduced 27-hydroxylase and ABCA1 message (to 62.4% +/- 2.2% and 71.1% +/- 3.9% of control, respectively). Incubation with prostaglandin (PG) E2 or PGD2 reversed reductions in both of these cholesterol transport proteins induced by NS398. Cholesterol-loaded THP-1 macrophages showed significantly increased foam cell transformation in the presence of NS398 versus control (42.7% +/- 6.6% versus 20.1% +/- 3.4%, p = 0.04) as determined by oil red O staining. Pharmacological inhibition of COX in monocytes is involved in downregulation of two proteins that mediate cholesterol efflux: cholesterol 27-hydroxylase and ABCA1. Because these proteins are anti-atherogenic, their downregulation may contribute to increased incidence of cardiac events in patients treated with COX inhibitors. Reversal of inhibitory effects on 27-hydroxylase and ABCA1 expression by PGD2 and PGE2 suggests involvement of their respective signaling pathways. NS398-treated THP-1 macrophages show greater vulnerability to form foam cells. Increased cardiovascular risk with COX inhibition may be ascribed at least in part to altered cholesterol metabolism

Colchicine is the only drug known to effectively prevent familial Mediterranean fever (FMF) attacks, as well as FMF-associated amyloidosis. Unfortunately, colchicine is neither always effective nor always well tolerated, leaving some patients and their physicians with inadequate weaponry to fight this hazardous disease. We present a patient with recurrent episodes of abdominal, scrotal, and joint attacks, who was diagnosed with FMF and advised to take colchicine. Diarrhea prevented optimal treatment with this drug and led to a trial of etanercept, with resolution of FMF manifestations. This case adds to a growing body of evidence suggesting that tumor necrosis factor (TNF) blockade may result in resolution and prevention of further FMF attacks

Primary fibromyalgia is a common yet poorly understood syndrome characterized by diffuse chronic pain accompanied by other somatic symptoms, including poor sleep, fatigue, and stiffness, in the absence of disease. Fibromyalgia does not have a distinct cause or pathology. Nevertheless, in the past decade, the study of chronic pain has yielded new insights into the pathophysiology of fibromyalgia and related chronic pain disorders. Accruing evidence shows that patients with fibromyalgia experience pain differently from the general population because of dysfunctional pain processing in the central nervous system. Aberrant pain processing, which can result in chronic pain and associated symptoms, may be the result of several interplaying mechanisms, including central sensitization, blunting of inhibitory pain pathways, alterations in neurotransmitters, and psychiatric comorbid conditions. This review provides an overview of the mechanisms currently thought to be partly responsible for the chronic diffuse pain typical of fibromyalgia.

The production of nitric oxide (NO) by chondrocytes is increased in human osteoarthritis. The excessive production of NO inhibits matrix synthesis and promotes its degradation. Furthermore, by reacting with oxidants such as superoxide anion, NO promotes cellular injury and renders the chondrocyte susceptible to cytokine-induced apoptosis. Thus, NO produced by activated chondrocytes in diseased cartilage may modulate disease progression in osteoarthritis and should therefore be considered a potential target for therapeutic intervention.

Because the mechanisms of Helicobacter pylori-induced gastric injury are incompletely understood, we examined the hypothesis that H. pylori induces matrix metalloproteinase-1 (MMP-1) secretion, with potential to disrupt gastric stroma. We further tested the role of CagA, an H. pylori virulence factor, in MMP-1 secretion. Co-incubation of AGS cells with Tx30a, an H. pylori strain lacking the cagA virulence gene, stimulated MMP-1 secretion, confirming cagA-independent secretion. Co-incubation with strain 147C (cagA(+)) resulted in CagA translocation into AGS cells and increased MMP-1 secretion relative to Tx30a. Transfection of cells with the recombinant 147C cagA gene also induced MMP-1 secretion, indicating that CagA can independently stimulate MMP-1 secretion. Co-incubation with strain 147A, containing a cagA gene that lacks an EPIYA tyrosine phosphorylation motif, as well as transfection with 147A cagA, yielded an MMP-1 secretion intermediate between no treatment and 147C, indicating that CagA tyrosine phosphorylation regulates cellular signaling in this model system. H. pylori induced activation of the MAP kinase ERK, with CagA-independent (early) and dependent (later) components. MEK inhibitors UO126 and PD98059 inhibited both CagA-independent and -dependent MMP-1 secretion, whereas p38 inhibition enhanced MMP-1 secretion and ERK activation, suggesting p38 negative regulation of MMP-1 and ERK. These data indicate H. pylori effects on host epithelial MMP-1 expression via ERK, with p38 playing a potential regulatory role

Cytokines such as TNF-alpha and IL-1beta play key roles in driving the inflammation and synovial cell proliferation that characterize rheumatoid arthritis (RA) joint destruction. It is, therefore, not surprising that therapies for RA have targeted these cytokines. While blockade of TNF-alpha or IL-1beta has been efficacious for many patients with RA, adequacy and maintenance of response are not universal, and increased risk of adverse events such as infection and malignancy remains a concern. Therefore, new targets in the treatment of RA continue to be examined. As interleukin-6 (IL-6) has been implicated in the pathogenesis of RA, blockade of its activity is of both scientific and clinical interest. The basic biology of IL-6, the in vitro animal data supporting its role in RA, and the human trials to date that test the possible efficacy of IL-6-directed therapy for RA are reviewed

Over the past decade, significant advances have been made regarding the pathogenesis, clinical implications, and treatment of hyperuricemia. While physicians have understood for at least a century that uric acid causes gout, we are now beginning to address the question of why hyperuricemia exists and the mechanisms by which uric acid acts to stimulate inflammation. This review focuses on (1) previously unknown biological roles of uric acid; (2) why the loss of the uricase gene and resultant hyperuricemia may have provided an evolutionary advantage to primates and, in particular, to humans; (3) the molecular effects of uric acid on inflammatory cells; and (4) novel antihyperuricemic agents currently under study