Tiny Cell Doorway Could Regrow Hair, Fight Cancer

After fifty years of scientific pursuit, researchers at the University of Cambridge have solved a fundamental energy mystery within our cells. Their work visualizes for the first time how a microscopic canal-like mechanism shuttles vital fuel molecules into mitochondria—the cellular powerhouses that convert sugar into usable energy.

The study, published April 18 in Science Advances, reveals the atomic structure of a molecular machine called the mitochondrial pyruvate carrier (MPC), which was first hypothesized in 1971 but remained structurally uncharacterized until now.

“Sugars in our diet provide energy for our bodies to function. When they are broken down inside our cells they produce pyruvate, but to get the most out of this molecule it needs to be transferred inside the cell’s powerhouses, the mitochondria,” said Dr. Sotiria Tavoulari, Senior Research Associate from the University of Cambridge and lead author on the study.

The carrier operates like a miniaturized canal lock system, with gates that open and close in sequence to transport pyruvate molecules across the otherwise impermeable inner mitochondrial membrane. This process enables cells to increase their energy production by 15-fold.

“It works like the locks on a canal but on the molecular scale,” explained Professor Edmund Kunji from the MRC Mitochondrial Biology Unit. “There, a gate opens at one end, allowing the boat to enter. It then closes and the gate at the opposite end opens to allow the boat smooth transit through.”

The Cambridge team utilized cryo-electron microscopy to visualize the carrier at nearly 165,000 times its actual size. This advanced imaging technique allowed researchers to see not only what the carrier looks like but also precisely how it functions.

PhD student Maximilian Sichrovsky, joint first author on the study, emphasized the significance of this structural insight: “Getting pyruvate into our mitochondria sounds straightforward, but until now we haven’t been able to understand the mechanism of how this process occurs.”

Beyond advancing fundamental biological knowledge, the research potentially opens new therapeutic avenues for multiple conditions. Since the carrier controls how mitochondria produce energy, it represents a promising drug target for diabetes, fatty liver disease, certain cancers, Parkinson’s disease, and even hair loss.

“Drugs inhibiting the function of the carrier can remodel how mitochondria work, which can be beneficial in certain conditions,” said Professor Kunji. In fatty liver disease, for instance, blocking the carrier could force cells to metabolize stored liver fat. Similarly, some cancer cells, particularly in prostate cancer, produce excess pyruvate carriers to fuel their rapid growth—making the carrier a potential target for starving these cells.

The research also explains how the carrier is regulated by pH differences across the mitochondrial membrane, a critical factor in its transport function. Understanding these mechanical details creates new opportunities for designing targeted drugs that could precisely control cellular metabolism.

This discovery culminates decades of scientific investigation, offering a window into one of life’s most fundamental energy production mechanisms. The Cambridge team collaborated with researchers from the Medical College of Wisconsin, the National Institutes of Health, and the Free University of Brussels to complete this work.

For certain tumors that depend heavily on pyruvate metabolism, disrupting this carrier could restrict their energy supply. Similarly, inhibiting the carrier in hair follicle cells may increase lactate production—potentially stimulating hair growth.

The detailed findings establish a structural foundation for developing precisely targeted medications that could address metabolic disorders with fewer side effects than current treatments. As Professor Kunji notes, this could be “a real game changer” for drug development.