Scientists uncover why statins cause muscle pain
Molecular mechanism of statin-induced muscle pain decoded
A team from the University of British Columbia (UBC), collaborating with colleagues at the University of Wisconsin-Madison, has elucidated the cellular cause of statins' adverse effects on muscles. These drugs are essential for lowering cholesterol and preventing heart attacks and strokes. However, they are frequently associated with muscle pain, weakness, and, in rare cases, tissue destruction that can lead to kidney failure. Using cryo-electron microscopy, a high-resolution imaging tool, the specialists demonstrated that statin molecules bind to a key protein in muscle cells. This binding forces open a channel that regulates calcium flow. The disruption causes a continuous leak of calcium ions, creating a toxic environment for the muscle tissue.
Statins remain one of the most important classes of drugs for treating cardiovascular disease. Over the years, they have saved millions of lives by controlling cholesterol. Yet, their benefits can be overshadowed by unpleasant side effects. A small number of patients suffer from severe muscle breakdown, a condition that can trigger renal failure. Research published in Nature Communications provides a clear mechanical explanation for these complications. It also opens the path toward developing safer statins that maintain cholesterol-lowering efficacy while reducing muscle damage.
Statins: vital but sometimes painful
To understand the processes inside muscle cells, the research teams turned to cryo-electron microscopy. This technique allows observation of protein structures with near-atomic precision. The investigation focused on the ryanodine receptor (RyR1), a protein that controls calcium release needed for muscle contraction. Under normal conditions, this receptor acts as a regulated gate. The researchers found that statins attach to this channel and hold it open. This causes uncontrolled calcium leakage into areas where it should be strictly regulated. „We could see, almost atom by atom, how the statins block this channel,”explained lead author Dr. Steven Molinarolo, a postdoctoral researcher in UBC's Department of Biochemistry and Molecular Biology. „This calcium leak explains why some patients experience muscle pain or, in extreme cases, life-threatening complications.” How statin triplets activate the channel The analysis focused on atorvastatin, a widely prescribed drug for lowering cholesterol.
Seeing the binding in action
Although this compound was the primary focus, the results suggest similar interactions may occur with other statins. One of the most surprising findings was how the molecules bind to the calcium channel. Instead of acting individually, three molecules occupy a specific niche within the protein. The first molecule binds when the channel is closed, facilitating its opening. Subsequently, two additional molecules enter the same niche and keep the channel open, allowing continuous calcium leakage. „This is the first time we have a clear image of how statins activate this channel,”stated Dr. Filip Van Petegem, a professor at UBC's Life Sciences Institute and senior author of the study. „It is a huge step forward, as it gives us a map for designing statins that do not interact with muscle tissue.” Designing safer alternatives This detailed understanding gives drug developers a starting point to correct the problem at its source.
Implications for future treatments
By modifying the molecular characteristics that interfere with muscle proteins, the frequency of unwanted effects can be reduced without compromising cholesterol control. Over 200 million people worldwide use statins. Although severe muscle injuries affect only a small percentage of patients, milder symptoms like pain, weakness, and fatigue are much more widespread. These conditions can be so distressing that many patients stop treatment, losing essential protection against cardiovascular disease.
Achieving this level of structural detail required using the cryo-electron microscopy facility at UBC's medical faculty. These observations link long-standing safety concerns with a specific molecular process, providing valuable data for future drug development. „Statins have been a pillar of cardiovascular care for decades,”emphasized Dr. Van Petegem. „Our goal is to make them even safer, so patients can benefit without the fear of severe side effects.”While more research and drug development are needed before these findings become new treatments, they indicate a promising direction. For the millions of people relying on statins to protect their hearts, future drugs with fewer muscle complications could make treatment more comfortable and improve daily quality of life.