Heme oxygenase-1 against vascular insufficiency: roles of atherosclerotic disorders

Kazunobu Ishikawa1

  • 1The First Department of Internal Medicine, Fukushima Medical University, Fukushima-city, Japan. kishikaw@fmu.ac.jp

Heme oxygenase (HO), an enzyme essential for heme degradation, shows anti-oxidative and anti-inflammatory properties via the production of bile pigments, carbon monoxide (CO) and ferritin induction under various pathophysiological conditions. A number of recent studies have shown biological effects of HO reaction in cardiovascular disorders. An inducible form of HO, HO-1, is induced by a variety of stresses such as oxidized lipoproteins, cytokines, hemodynamic changes, angiotensin II and nitric oxide (NO) in vascular wall. HO-1 induction seems to function as an adaptive response against these injurious stimuli. HO-1 induction in artery wall scavenges reactive oxygen species, which leads to the attenuation of monocyte adhesion and chemotaxis. HO-1 induction also reduces lipid peroxidation in plasma and artery wall. These properties of HO-1 suggest anti-atherogenic roles of this enzyme. In this review, roles of endothelial HO-1 expression and bilirubin in atherogenesis are also discussed. HO-1 also seems to play a significant role in restenosis after angioplasty, which is a major clinical problem associated with atherosclerosis. Recent progress in human HO-1 genetics supports these experimental results. This review aims to reaffirm current problems in the biological aspects of HO and suggest future research direction and clinical application.

Related Concept Videos

Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
Ischemic Heart Disease: Overview01:17

Ischemic Heart Disease: Overview

Ischemic heart disease occurs when the heart's blood supply dwindles, causing an ominous lack of oxygen and nutrients. This deficiency, stemming from reduced or obstructed blood flow, spells danger, leading to heart muscle damage and dysfunction.
Atherosclerosis, the primary malefactor, orchestrates this dangerous condition. It manifests as the accumulation of fatty deposits, akin to insidious plaques, within arterial walls. As time elapses, these plaques metamorphose, hardening and narrowing...
Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure01:16

Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure

Oxygen therapy has emerged as a significant tool in enhancing the quality of life for patients suffering from pulmonary arterial hypertension (PAH). While this therapy has principally been studied on patients with significant hypoxemia, this therapeutic approach helps prevent potential organ damage and can be administered in the comfort of one's home.
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue, improving...
Oxygen Transport in the Blood01:27

Oxygen Transport in the Blood

Hemoglobin (Hb) is a crucial molecule in the human body, consisting of four polypeptide chains, each bound to an iron-containing heme group. This unique structure enables hemoglobin to bind to oxygen, with each molecule capable of combining with four molecules of oxygen, leading to rapid and reversible oxygen loading. When fully loaded with oxygen, it is called oxyhemoglobin, while hemoglobin that has released oxygen is called reduced hemoglobin or deoxyhemoglobin. As hemoglobin binds oxygen,...
Hypertension II: Pathophysiology01:29

Hypertension II: Pathophysiology

Hypertension is a chronic condition in which the blood's force against artery walls is excessively high, posing risks such as heart disease. The condition's underlying mechanisms involve complex interactions among the cardiovascular, kidney, and autonomic nervous systems.Renin-Angiotensin-Aldosterone System (RAAS): This system significantly influences blood pressure regulation. When blood pressure decreases, the kidneys secrete renin. This enzyme transforms angiotensinogen, a plasma protein,...
Pulmonary Hypertension: Classification and Pathogenesis01:30

Pulmonary Hypertension: Classification and Pathogenesis

Pulmonary hypertension (PH) is a severe health condition in which the mean pulmonary arterial pressure increases to 25 mmHg or more, even when the body is at rest. This high pressure in the blood vessels that transport blood from the heart to the lungs can cause various symptoms, including shortness of breath, can lead to right heart failure, and significantly affect the overall quality of life.
There are various classifications for PH, each relating to different underlying causes and also...