Knocking out the gene for the microRNA in mice protected against hypertrophy and fibrosis as a response to cardiac stress.
Previous research suggested that a microRNA expressed in cardiac myocytes, called miR-208, plays a role in causing hypertrophy of myocytes and fibrosis when the heart is stressed. A team from Texas created mice in which both DNA alleles that code for miR-208 were knocked out, and compared the response to cardiac stress in the knockout mice and normal mice.
Banding of the thoracic aorta to create hypertension caused cardiomyocyte hypertrophy and fibrosis in normal mice but not in knockout mice. The knockout mice were similarly protected against another type of stress, induced hyperthyroidism.
Comment
This study is intriguing because it suggests that knocking out a specific microRNA might have clinical benefits. Although knoc…