BIOCHEMISTRY OF GOUT

Project Abstract

Gout is a complex form of arthritis characterized by the deposition of monosodium urate crystals in joints and tissues, leading to inflammation and severe pain. This research project aims to delve into the biochemistry of gout, focusing on the underlying mechanisms that contribute to the development and progression of this condition. One of the key components in the biochemistry of gout is the role of uric acid, a natural byproduct of purine metabolism. Elevated levels of uric acid in the blood, known as hyperuricemia, are a major risk factor for developing gout. Uric acid crystals form in the joints when the concentration exceeds its solubility limit, triggering an inflammatory response by the immune system. The immune system's response to uric acid crystals plays a critical role in the pathogenesis of gout. Neutrophils are the first immune cells recruited to the site of crystal deposition, releasing inflammatory mediators that further propagate the inflammatory cascade. This leads to the activation of macrophages and other immune cells, resulting in the production of pro-inflammatory cytokines and chemokines that exacerbate the inflammatory response. Moreover, the NLRP3 inflammasome, a multiprotein complex involved in the innate immune response, has been implicated in the pathogenesis of gout. Activation of the NLRP3 inflammasome by uric acid crystals leads to the cleavage of pro-inflammatory cytokines such as interleukin-1? (IL-1?), contributing to the inflammatory response in gout. In addition to the immune system's response, the role of enzymes involved in purine metabolism, such as xanthine oxidase, is crucial in the biochemistry of gout. Xanthine oxidase catalyzes the conversion of hypoxanthine to xanthine and xanthine to uric acid, thereby influencing the production of uric acid in the body. Inhibition of xanthine oxidase is a common therapeutic approach in managing gout by reducing uric acid production. Understanding the intricate biochemistry of gout is essential for developing targeted therapeutic strategies to alleviate symptoms and prevent disease progression. By elucidating the molecular mechanisms underlying gout, this research project aims to provide valuable insights into potential drug targets and interventions for this debilitating condition.

Project Overview

<p> </p><p><strong><br>1.1 &nbsp; &nbsp; Introduction</strong></p><p>Gout was described by Hippocrates as “the disease of kings” due to its association with rich diet. (Falasca, 2006). Gout is a heterogeneous group of diseases resulting from the deposition of urate (as monosodium urate monohydrate) crystals in supersaturated extracellular fluids. It’s also a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot, and swollen joint (Chen and Schumacher, 2008). Pain typically comes on rapidly in less than twelve hours (Richette and Bardin, 2010). The joint at the base of the big toe is affected in about half of cases (Schlesinger, 2010). It may also result in tophi, kidney stones, or urate nephropathy (Richette and Bardin, 2010).</p><p>Gout is due to persistently elevated levels of uric acid in the blood. This occurs due to a combination of diet and genetic factors (Richette and Bardin, 2010). At high levels, uric acid crystallizes and the crystals deposit in joints, tendons, and surrounding tissues, resulting in an attack of gout which may be first acute an then to chronic gouty arthritis. Nodular masses of monosodium urate crystals may be deposited in the soft tissues, resulting in chronic tophaceous gout. Gout occurs more commonly in those who regularly eat meat or seafood, drink beer, or are overweight (Beyl et al., 2016). Diagnosis of gout may be confirmed by the presence of crystals in the joint fluid or tophus. Blood uric acid levels may be normal during an attack (Richette and Bardin, 2010).</p><p>Gout affects about 1 to 2% of the Western population at some point in their lives. It has become more common in recent decades (Richette and Bardin, 2010). This is believed to be due to increasing risk factors in the population, such as metabolic syndrome, longer life expectancy, and changes in diet (Richette and Bardin, 2010). Older males are most commonly affected.</p><p><strong>1.2 &nbsp; &nbsp; Signs and symptoms</strong></p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Gout can present in multiple ways, although the most usual is a recurrent attack of acute inflammatory arthritis (a red, tender, hot, swollen joint) (Chen and Schumacher, 2008). The metatarsal-phalangeal joint at the base of the big toe is affected most often, accounting for half of cases (Schlesinger, 2010). Other joints, such as the heels, knees, wrists, and fingers, may also be affected (Schlesinger, 2010). Joint pain usually begins over 2–4 hours and during the night (Schlesinger, 2010). This is mainly due to lower body temperature (Eggebeen, 2007). Other symptoms which may rarely occur along with the joint pain include fatigue and a high fever (Eggebeen, 2007).</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Long-standing elevated uric acid levels (hyperuricemia) may result in other symptoms, including hard, painless deposits of uric acid crystals known as tophi. Extensive tophi may lead to chronic arthritis due to bone erosion (Terkeltaub, 2010). Elevated levels of uric acid may also lead to crystals precipitating in the kidneys, resulting in stone formation and subsequent urate nephropathy (Tausche et al., 2009)</p> <br><p></p>