Showing papers by "Leo E. Otterbein published in 2010"

The therapeutic potential of carbon monoxide.

Abstract: Carbon monoxide (CO) is increasingly being accepted as a cytoprotective and homeostatic molecule with important signalling capabilities in physiological and pathophysiological situations. The endogenous production of CO occurs through the activity of constitutive (haem oxygenase 2) and inducible (haem oxygenase 1) haem oxygenases, enzymes that are responsible for the catabolism of haem. Through the generation of its products, which in addition to CO includes the bile pigments biliverdin, bilirubin and ferrous iron, the haem oxygenase 1 system also has an obligatory role in the regulation of the stress response and in cell adaptation to injury. This Review provides an overview of the physiology of CO, summarizes the effects of CO gas and CO-releasing molecules in preclinical animal models of cardiovascular disease, inflammatory disorders and organ transplantation, and discusses the development and therapeutic options for the exploitation of this simple gaseous molecule.

Nitric oxide-dependent bone marrow progenitor mobilization by carbon monoxide enhances endothelial repair after vascular injury.

Abstract: Carbon monoxide (CO) has emerged as a vascular homeostatic molecule that prevents balloon angioplasty-induced stenosis via antiproliferative effects on vascular smooth muscle cells. The effects of CO on reendothelialization have not been evaluated.

Hypoxia activates a Ca2+-permeable cation conductance sensitive to carbon monoxide and to GsMTx-4 in human and mouse sickle erythrocytes.

Abstract: BACKGROUND Deoxygenation of sickle erythrocytes activates a cation permeability of unknown molecular identity (Psickle), leading to elevated intracellular [Ca(2+)] ([Ca(2+)](i)) and subsequent activation of K(Ca) 3.1. The resulting erythrocyte volume decrease elevates intracellular hemoglobin S (HbSS) concentration, accelerates deoxygenation-induced HbSS polymerization, and increases the likelihood of cell sickling. Deoxygenation-induced currents sharing some properties of Psickle have been recorded from sickle erythrocytes in whole cell configuration. METHODOLOGY/PRINCIPAL FINDINGS We now show by cell-attached and nystatin-permeabilized patch clamp recording from sickle erythrocytes of mouse and human that deoxygenation reversibly activates a Ca(2+)- and cation-permeable conductance sensitive to inhibition by Grammastola spatulata mechanotoxin-4 (GsMTx-4; 1 microM), dipyridamole (100 microM), DIDS (100 microM), and carbon monoxide (25 ppm pretreatment). Deoxygenation also elevates sickle erythrocyte [Ca(2+)](i), in a manner similarly inhibited by GsMTx-4 and by carbon monoxide. Normal human and mouse erythrocytes do not exhibit these responses to deoxygenation. Deoxygenation-induced elevation of [Ca(2+)](i) in mouse sickle erythrocytes did not require KCa3.1 activity. CONCLUSIONS/SIGNIFICANCE The electrophysiological and fluorimetric data provide compelling evidence in sickle erythrocytes of mouse and human for a deoxygenation-induced, reversible, Ca(2+)-permeable cation conductance blocked by inhibition of HbSS polymerization and by an inhibitor of strctch-activated cation channels. This cation permeability pathway is likely an important source of intracellular Ca(2+) for pathologic activation of KCa3.1 in sickle erythrocytes. Blockade of this pathway represents a novel therapeutic approach for treatment of sickle disease.

Molecular Pathways in the Progression of Hormone-Independent and Metastatic Prostate Cancer

Abstract: Once prostate cancer becomes castration resistant, cancer cells may rapidly gain the ability to invade and to metastasize to lymph nodes and distant organs. The progression through hormone-dependent to hormone-independent/castration-resistant and metastatic PCa is poorly understood. In this review paper, we provide an overview on the cellular and molecular mechanisms underlying the process of tumor cell invasion and metastasis in prostate cancer. We specifically present the most recent findings on the role of multiple cellular signaling pathways including androgen receptor (AR), mitogen-activated protein kinases (MAPK), Akt, transforming growth factor b (TGFb interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in the development of hormone-independent/castration-resistant prostate cancer. In addition, we also discuss the recent findings on signatures of gene expression during prostate cancer progression. Our overviews on the novel findings will help to gain better understanding of the complexity of molecular mechanisms that may play an essential role in the development of castration-resistant and metastatic prostate cancer. It will also shed light on the identification of specific targets and the design of effective therapeutic drug candidates.