Scientists have found an alternative drug to statins that could help control high cholesterol. Researchers at the University of California San Diego School of Medicine have discovered a hidden biological pathway that explains why high-cholesterol diets dismantle the liver’s defenses. The team has also identified a drug candidate already proven safe in humans that could potentially target this pathway.

Understanding the Biological Pathway

The liver is the main organ involved in removing cholesterol from the blood. It does this through LDL receptors, which sit on the surface of liver cells and act like docking stations, grabbing LDL cholesterol from the bloodstream and pulling it inside the cell for processing. However, a high-cholesterol diet reduces the liver’s ability to clear cholesterol from the blood, and the new discovery explains a critical piece of that puzzle.

A protein called Ral, activated by high dietary cholesterol, is the key to this process. The more Ral is activated, the fewer LDL receptors remain available to clear cholesterol from the blood. The research team found that blocking an enzyme called cathepsin A, or CTSA, with a small molecule inhibitor was enough to stabilize LDL receptors and dramatically lower circulating LDL cholesterol in mice.

Potential Treatment Option

A CTSA inhibitor has already been through the early stages of drug development, with the initial goal of treating heart failure. Although it was eventually shelved for strategic reasons, the drug had previously advanced to a Phase 1 clinical trial, where it was successfully tested for safety. The new discovery suggests that the investigational drug is already ready for testing in a Phase 2 trial for high cholesterol.

Original reporting: KTBS 3 (Shreveport) — read the source article.