Researchers target BCAT1 enzyme to reduce post-heart attack scarring
Researchers at Kyushu University and Tokushima University have identified that the enzyme BCAT1 helps drive cardiac fibrosis after a heart attack by maintaining the supply of proline needed for collagen production. The treatment remained effective even when administered seven days after a cardiac event, offering a potential path to limit pathological scarring without disrupting normal tissue repair.
How BCAT1 drives collagen production and cardiac stiffening
Heart failure frequently develops after a heart attack because the body’s repair mechanism produces excessive scar tissue, a process known as fibrosis. Collagen provides necessary structural support, but overproduction stiffens the heart muscle and impairs its ability to pump blood. According to Technology Networks, fibrosis contributes to 45 percent of deaths in developed countries, yet no definitive therapy directly suppresses the condition.
To investigate how scar-producing cells called myofibroblasts obtain building blocks for collagen, researchers examined metabolic pathways that maintain proline, an amino acid comprising around 20 percent of collagen. By comparing stressed genes with those activated in mouse hearts after a heart attack, the team identified five overlapping candidates and focused on BCAT1. While barely detectable in healthy mouse hearts, BCAT1 expression spiked in collagen-producing cells as fibrosis progressed, establishing the enzyme as a key metabolic control point.
Experimental results with genetic deletion and ERG240 treatment
The research team tested the therapeutic potential of targeting BCAT1 through two distinct methods in mice. Genetically engineered mice lacking the enzyme produced less collagen, formed less scar tissue, and maintained better heart function than control animals following a heart attack. Administration of the BCAT1 inhibitor ERG240 yielded similar results, successfully reducing scarring and preserving cardiac function even when treatment began seven days post-injury during the transition from acute inflammation to the chronic phase.
Analysis of human tissue revealed elevated BCAT1 levels associated with increased fibrosis in heart tissue from patients with heart failure. Higher levels of the enzyme were also detected in the livers of patients with fatty liver disease, indicating that the pathway might drive fibrosis across multiple organs. Because BCAT1 appears largely absent from healthy tissue and primarily active in scar-forming cells, targeted therapies could theoretically reduce fibrosis without harming normal cells.
Questions remaining before clinical trials begin
Despite promising preclinical results, researchers have not yet established BCAT1 as a clinically validated target in humans. Future studies must determine how effectively the inhibitor engages living tissue, identify optimal dosing regimens, and evaluate safety across diverse disease models. Scientists also need to confirm whether inhibiting the enzyme interferes with normal metabolic functions or standard tissue repair mechanisms. The team plans to investigate the pathway’s role in liver fibrosis and develop clinically applicable therapies, though safety and efficacy in patients remain to be proven.
Frequently asked questions about BCAT1 and cardiac fibrosis
What is the primary function of BCAT1 in cardiac fibrosis?
BCAT1 is an enzyme that helps maintain the supply of the amino acid proline, which myofibroblasts require to synthesize high levels of collagen during tissue repair.
How soon after a heart attack was ERG240 effective in animal studies?
Treatment with the BCAT1 inhibitor ERG240 successfully reduced scarring and preserved heart function even when administered seven days after the injury occurred.
Are there human trials currently testing BCAT1 inhibitors for heart failure?
No clinical trials are currently underway. The research remains in the preclinical phase, having been tested primarily in mice alongside an analysis of human tissue samples from patients with heart failure and fatty liver disease.
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