Selinexor, a CRM1 inhibitor with anti-senescence activity, modulates the non- coding transcriptome of Hutchinson–Gilford progeria syndrome fibroblasts

Aging is a universal process, a slow and steady shift in how our bodies function that eventually leads to frailty and disease. While this happens to everyone, some people experience it with terrifying speed. Hutchinson-Gilford progeria syndrome, often called progeria, is a rare genetic condition where children age decades in just a few years. This rapid decline is caused by a single mistake in a gene that normally builds a structural protein for the cell's nucleus, the command center that holds our DNA. When this gene mutates, it creates a malformed protein called progerin. This defective protein gets stuck in the nuclear wall, distorting the shape of the nucleus and throwing a wrench into the cell's daily operations. The cells stop dividing, become damaged, and die prematurely, leading to the accelerated aging seen in patients. For decades, scientists have focused on how this bad protein changes the instructions for making other proteins, but they have largely ignored a vast, hidden layer of genetic material that does not make proteins at all.

This hidden layer consists of long non-coding RNAs. Think of the genome as a massive library. Most of the books in this library are instruction manuals for building proteins, the machines that run our cells. However, a huge portion of the library contains books that do not give direct instructions for building things. Instead, these long non-coding RNAs act like librarians or managers; they decide which instruction manuals get read, how loudly they are read, and when they should be closed. In a healthy cell, these managers keep the library running smoothly. In a cell with progeria, the distorted nucleus likely confuses these managers, causing them to mismanage the library. This confusion could be a major reason why the cells age so quickly. Until now, no one had mapped exactly how these genetic managers behave in progeria cells or whether a specific drug could fix their behavior.

Researchers set out to explore this uncharted territory by looking at the genetic activity of skin cells taken from a patient with progeria and comparing them to healthy skin cells. They used a powerful technique that reads the entire genetic output of the cells, allowing them to see not just the protein-making instructions, but also the activity of these long non-coding RNA managers. The analysis revealed a clear difference between the two groups. In the progeria cells, the managers were behaving erratically. Some were shouting instructions that should have been quiet, while others were silent when they should have been active. This chaos was not random; it was concentrated in specific areas of the cell's operations, particularly in the pathways that control how fast cells grow and when they decide to stop dividing and enter a state of permanent rest, known as senescence. The study found that the genetic managers were heavily involved in a critical signaling system called mTOR, which acts as a central hub for cell growth and nutrient sensing. In the diseased cells, this system was stuck in a state of dysfunction.

The team then tested whether a drug called selinexor, which had previously shown promise in slowing down the aging of these cells, could also restore order to this genetic library. Selinexor works by blocking a specific exit door in the nucleus, preventing certain proteins from leaving and thereby changing how the cell processes information. When the researchers treated the progeria cells with this drug, the results were striking. The chaotic behavior of the long non-coding RNA managers began to calm down. The drug did not just turn everything off or on; it specifically reversed the errors caused by the progerin protein. The managers that were shouting too loud quieted down, and those that were too quiet began to speak again. This correction brought the genetic profile of the diseased cells much closer to that of the healthy cells.

To be sure these findings were real and not just a computer glitch, the scientists performed a second, more direct check on four specific genetic managers that stood out in their data. They measured the levels of these four molecules in the cells using a precise laboratory test. The results confirmed the initial discovery. In the untreated progeria cells, three of these managers were present in much higher amounts than in healthy cells, while one was significantly lower. After treatment with the drug, the levels of these four molecules shifted back toward normal. One of the most important managers, known as H19, was found to be extremely high in the diseased cells, a state that the drug successfully lowered. Another manager, MBNL1-AS1, was too low in the disease state but rose back up after treatment. The researchers also tested this in a different type of cell model where they could turn the production of the bad progerin protein on and off like a switch. When they turned the bad protein on, the levels of these managers changed exactly as they had seen in the patient cells. When they added the drug, the changes reversed.

The study suggests that the drug selinexor helps cells resist aging not just by fixing the structural problems caused by the bad protein, but by correcting the genetic management system that controls cell growth and rest. By restoring the proper balance of these long non-coding RNAs, the drug appears to re-engage the pathways that keep cells healthy and prevent them from entering a state of permanent aging. The researchers identified that this correction specifically targets the mTOR pathway and the cellular senescence program, two critical systems that go haywire in progeria. While the study does not prove that this is the only way the drug works, it provides strong evidence that these genetic managers are key players in the disease and that fixing them is a viable strategy for treatment. The work highlights that understanding aging requires looking beyond the protein-making instructions to the complex management system that controls them, offering a new perspective on how we might one day slow down or reverse the aging process in humans.