CRISPR gene editing in blood stem cells linked to premature aging effects: Study offers solutions

> Scientists at the San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), Milan, have found that gene editing using CRISPR-Cas9 in combination with AAV6 vectors can trigger inflammatory and senescence-like responses in blood stem cells, compromising their long-term ability to regenerate the blood system.

> Homology-directed repair (HDR)-based gene editing in hematopoietic stem and progenitor cells (HSPCs) holds great promise for the treatment of genetic blood diseases but translating these approaches into safe and effective clinical therapies for patients remains a major challenge.

> The team of Di Micco at SR-Tiget discovered that CRISPR-Cas9 editing, especially when using AAV6 vectors to deliver the repair template, activates a strong DNA damage response (DDR) and inflammatory signals driven by p53 and IL-1/NF-κB pathways. This **leads to inflammation and a senescence-like state** that reduces the regenerative capacity of the edited cells post-transplantation.

> “We found that a fraction of **gene-edited hematopoietic stem cells shows signs of premature aging**,” explains Dr. Di Micco. “This reduces their ability to regenerate blood cells after transplantation, which can limit the long-term success and therapeutic benefit of gene therapy.”

> “Our findings suggest that stem cells retain a ‘memory’ of the genetic engineering process.” **To counteract this adverse effect**, the researchers tested two complementary strategies: transient p53 inhibition and the use of anti-inflammatory agents, particularly Anakinra—a clinically approved IL-1 receptor antagonist. “Both approaches **significantly reduced senescence markers in edited HSPCs and improved their ability to regenerate** a healthy, diverse blood system in preclinical models.