Current Drug Targets - Volume 11, Issue 12, 2010

The heme oxygenase (HO) enzyme reaction has initially been described more that 40 years ago [1]. HO catalyzes the degradation of the redox-reactive molecule heme into equimolar amounts of bilirubin, carbon monoxide (CO) and iron. Two genetically distinct isozymes of HO, HO-1 and HO-2, have been identified and exhibit distinct patterns of cell- and tissue- specific gene expression. In contrast to the constitutive isofor Read More

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) remain major causes of morbidity and mortality in critical care medicine despite advances in therapeutic modalities. ALI can be associated with sepsis, trauma, pharmaceutical or xenobiotic exposures, high oxygen therapy (hyperoxia) and mechanical ventilation. The stress protein heme oxygenase-1 (HO-1) provides an inducible defense mechanism Read More

As an enzyme, heme oxygenase (HO) can provide substantial cellular protection. By eliminating free heme and generating iron, biliverdin, as well as carbon monoxide, HO exerts anti-inflammatory, anti-proliferative, antioxidative, and vasodilatory effects. The inducible form of HO, heme oxygenase-1 (HO-1) can be upregulated by harmful stimuli in most human cell types. In such a way, cells utilize HO-1 as a mechanism of Read More

Heme oxygenase-1 (HO-1) metabolizes heme to generate carbon monoxide (CO), biliverdin, and iron. Biliverdin is subsequently metabolized to bilirubin by biliverdin reductase. HO-1 has recently emerged as a promising therapeutic target in the treatment of vascular disease. Pharmacological induction or gene transfer of HO-1 ameliorates vascular dysfunction in animal models of atherosclerosis, post-angiopla Read More

Heme oxygenase-1 (HO-1), an enzyme degrading heme to carbon monoxide, free iron, and biliverdin, participates in the cell defence against oxidative stress and it has been speculated that it might be a new therapeutic target for neuroprotection. In this review, we discuss recent findings on the regulation of the HO-1 gene, Hmox1, in the brain with particular focus on the transcription factors Nrf2 and HIF-1. Functional poly Read More

The lungs are a major target for various inflammatory, oxidative, carcinogenic or infectious stressors, which result in a range of lung diseases. Induction of heme oxygenase-1 (HO-1) during acute and chronic lung processes is a crucial defense mechanism. HO-1 catalyzes the degradation of free cellular heme to iron, carbon monoxide (CO) and biliverdin which is eventually converted to bilirubin by biliverdin reductase. In addit Read More

Heme oxygenase (HO)-1 is the inducible isoform of the first and rate-limiting enzyme of heme degradation. HO-1 has potent antioxidant and also anti-inflammatory functions, the underlying mechanisms of which are not well understood. Together with antioxidant carbon monoxide and biliverdin, HO produces reactive iron, which unambiguously connects this enzyme with the iron metabolism and its potential toxicity. A lin Read More

Heme oxygenase-1 (HO-1) degrades heme to carbon monoxide (CO), biliverdin, and ferrous iron. As HO-1 expression is highly increased by stressful conditions, the major role of the enzyme is the protection against oxidative injury. Additionally, it regulates cell proliferation, modulates inflammatory response and facilitates angiogenesis. Beneficial activities of HO-1 have been recognized in many pathological states e.g. Read More

Wound healing is an intricate process requiring the concerted action of keratinocytes, fibroblasts, endothelial cells, and macrophages. Here, we review the literature on normal wound healing and the pathological forms of wound healing, such as hypertrophic or excessive scar formation, with special emphasis on the heme-heme oxygenase (HO) system and the versatile effector molecules that are formed after HO-mediated h Read More

The range and diversity of functions of biliverdin reductase (BVR) are unmatched by any enzyme characterized to date. BVR is the sole catalyst for the conversion of biliverdin-IXα, the activity product of the stress-inducible HO-1 and the constitutive HO-2, to bilirubin-IXα. Bilirubin is both cytoprotective and cytotoxic, quenches reactive oxygen species (ROS) and inhibits inflammatory and mitogen-induced ROS-mediated re Read More

The perception that carbon monoxide (CO) is poisonous and life-threatening for mammalian organisms stems from its intrinsic propensity to bind iron in hemoglobin, a reaction that ultimately leads to impaired oxygen delivery to tissues. From evolutionary and chemical perspectives, however, CO is one of the most essential molecules in the formation of biological components and its interaction with transition metals is at the or Read More

Prostanoids, consisting of prostaglandins and thromboxane, are cyclooxygenase metabolites of arachidonic acid released in various pathophysiological conditions which exert a range of actions mediated through their respective receptors expressed on target cells. Although it has been difficult to analyze the physiological role of prostanoids, recent developments in both the disruption of the respective gene and rec Read More

The diseases caused by the trypanosomatid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania are widely distributed throughout the world. Because of the toxic side-effects and the economically unviable cost of the currently used pharmaceutical treatments, the search for new drug targets continues. Since the antioxidant metabolism in these parasites relies on trypanothione [T(SH)2], a functional analog of Read More