NADPH oxidases are a family of enzymes that generate reactive oxygen species (ROS). The NOX1 (NADPH oxidase 1) and NOX2 oxidases are the major sources of ROS in the artery wall in conditions such as hypertension, hypercholesterolaemia, diabetes and ageing, and so they are important contributors to the oxidative stress, endothelial dysfunction and vascular inflammation that underlies arterial remodelling and atherogenesis. In this Review, we advance the concept that compared to the use of conventional antioxidants, inhibiting NOX1 and NOX2 oxidases is a superior approach for combating oxidative stress. We briefly describe some common and emerging putative NADPH oxidase inhibitors. In addition, we highlight the crucial role of the NADPH oxidase regulatory subunit, p47phox, in the activity of vascular NOX1 and NOX2 oxidases, and suggest how a better understanding of its specific molecular interactions may enable the development of novel isoform-selective drugs to prevent or treat cardiovascular diseases.

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Combating oxidative stress in vascular disease: NADPH oxidases as therapeutic targets

Intranasal delivery of biologics to the central nervous system

Cross talk between mitochondria and NADPH oxidases

Adult mammalian hearts respond to injury with scar formation and not with cardiomyocyte proliferation, the cellular basis of regeneration. Although cardiogenic progenitor cells may maintain myocardial turnover, they do not give rise to a robust regenerative response. Here we show that extracellular periostin induced reentry of differentiated mammalian cardiomyocytes into the cell cycle. Periostin stimulated mononucleated cardiomyocytes to go through the full mitotic cell cycle. Periostin activated alphaV, beta1, beta3 and beta5 integrins located in the cardiomyocyte cell membrane. Activation of phosphatidylinositol-3-OH kinase was required for periostin-induced reentry of cardiomyocytes into the cell cycle and was sufficient for cell-cycle reentry in the absence of periostin. After myocardial infarction, periostin-induced cardiomyocyte cell-cycle reentry and mitosis were associated with improved ventricular remodeling and myocardial function, reduced fibrosis and infarct size, and increased angiogenesis. Thus, periostin and the pathway that it regulates may provide a target for innovative strategies to treat heart failure.

Periostin induces proliferation of differentiated cardiomyocytes and promotes cardiac repair

Angiotensin has many different actions, most of which relate, either directly or indirectly, to the regulation of blood pressure, fluid, and electrolyte homeostasis (1, 2). In addition to potent vasoconstrictor effects, actions ofangiotensin on vasculature include the stimulation ofprostaglandin release (3), the modulation of angiotensin receptor number (4), and the stimulation of angiogenesis (5). Angiotensin also has important actions on the central and peripheral nervous systems, the adrenal, kidney, intestine, and heart (6-1 1). Given these multiple diverse actions of angiotensin, two important questions are (a) which of these actions represent normal physiological events, and (b) whether such actions may assume a pathogenic role. These questions have recently been placed in sharper focus by the clinical application of inhibitors of the renin-angiotensin system (RAS),' and in particular, the use of converting enzyme inhibitors (CEIs) for the treatment of hypertension. Any attempt to answer these questions requires an accurate concept ofthe RAS. The purpose of this review is to discuss new concepts concerning angiotensin production by the circulating RAS, how these relate to angiotensin production within tissues, and the possible mechanisms by which CEIs lower blood pressure. The study of tissue angiotensin systems is still at an early stage. In this review I have attempted to synthesize a coherent model of the interaction between the circulating and tissue angiotensin systems, which might assist in the interpretation of new developments in this area.

/pdf/circulating-and-tissue-angiotensin-systems-43t6kf1z4q.pdf

Circulating and tissue angiotensin systems.

"The present results indicate that there is a close relationship between the incretory function of the kidney, which is shown by the discharge of renin and similar materials, and the function of the adrenal cortex, especially the zona glomerulosa, which is the place of production of the sodium-retaining hormone aldosterone . Salt load inhibits the production of renin and aldosterone, while salt deprivation stimulates the production of both. The excess of sodium-retaining corticoids (DOC or aldosterone) together with sodium suppress the secretion of renin, while a deficiency of cortical hormones (adrenalectomy, morbus Addison) increase it." ... "Under these conditions the development of experimental renal hypertension could be explained as follows: the narrowing of the renal artery stimulates the secretion of renin which itself increases the formation or discharge of mineralocorticoid hormones (aldosterone or similarly acting corticoids). The resulting retention of sodium does not lead to the normal reduction of renin secretion in the ischemic kidney, so that corticoid production in the adrenal cortex is further stimulated despite no need for it."

E. Hackenthal

Papers

The renin-angiotensin-aldosterone system. Past, present and future.