狭心症・認知症に対する超音波を用いた低侵襲治療の開発と臨床試験

In aging society, ischemic cardiovascular diseases and cognitive disorders both severely affect patient quality of life and care burden for its family or society. Ischemic heart disease is one of the major causes of death in developed countries, and its morbidity is also increasing. Dementia is the major cause of reducing activity of daily living (ADL) in high-aged society. And the number of dementia patients is growing as the population is rapidly aging. Recently, ischemic cardiovascular diseases and some of dementia are said to share major risk factors, such as dyslipidemia, hypertension, diabetes mellitus, and aging. Long-term exposure to these risk factors results in the impairment of vascular endothelial functions. Thus, the endothelium has been recognized as an important and common therapeutic target for prevention and treatment of cardiovascular diseases and dementia. Vascular endothelial cells cover the inner surface of blood vessels and are directly subjected to blood flow-induced mechanical stimuli including shear stress. These stimuli invoke specific responses within the cells, leading to changes in their intrinsic structure and function. Endothelial cells may sense these stimuli and convert them into a sequence of biological responses. On the other hand, ultrasound has already been a diagnostic imaging device for over 50 years and has become indispensable as a diagnostic tool now in clinical practice because of its convenience and wide applicability. Recently, it has been reported that when certain ultrasounds are irradiated on living tissues under specific conditions, they can promote angiogenesis and cell proliferation, and can contribute to improving the blood flow or function of organs. In our department, we focus on the characteristics of such unknown ultrasonic waves, and started the research that it can be applied clinically and can be used for the treatment of ischemic diseases. After the detailed verification, we reported that low-intensity pulsed ultrasound (LIPUS) induced angiogenesis in animal models of cardiovascular diseases and dementia, which resulted in the improvement of cardiac ejection fraction and cognitive function. Here, we would like to introduce a new invasive approach for the treatment of ischemic cardiovascular diseases and cognitive disorders. (343 words)