Pioneering AAV Gene Therapy Reverses Early Kidney Damage in Diabetic Mice

BRISTOL, UK – October 14, 2025 – Researchers at the University of Bristol have demonstrated that a pioneering AAV (Adeno-associated virus) gene therapy can significantly reduce early signs of diabetic kidney disease (diabetic nephropathy) in mice with diabetes. The findings, published in Molecular Therapy, pave the way for a potential new, single-intervention treatment to protect against one of the most common and serious complications of diabetes.

Targeting the Root Cause in the Glomerulus
Diabetic kidney disease, which affects one in three people with diabetes, starts in the glomerulus, the kidney’s tiny filters. Normally, the protein VEGFC maintains the health of the glomerulus’s blood vessel lining. In diabetes, this lining becomes damaged, a problem that current treatments can only slow down, not resolve.

The therapy, led by Dr. Rebecca Foster and team, utilizes a harmless AAV virus as a “microscopic postman” to deliver the VEGFC gene directly into the glomerulus cells. Once the genetic cargo is delivered, it instructs the kidney filter cells to produce more of the protective VEGFC protein. This is the first therapy to directly target the root of kidney disease in the glomerulus, offering the potential for a one-time, long-term protective effect.

Significant Efficacy Demonstrated in Preclinical Study
In mice with Type 1 diabetes, the gene therapy successfully increased VEGFC levels in the kidney and resulted in a 64% reduction in protein leakage into the urine. A drop of 30% or more is considered a meaningful indicator that kidney damage is slowing.

Dr. Foster stated that the goal was to investigate whether gene therapy could offer a viable, more targeted, long-term solution.

“This approach has not been explored before in pre-clinical models and offers a long-term solution for those who are at risk of developing kidney disease,” she said.

The research remains at an early stage in mice, but the study provides strong evidence for an urgently needed way to intervene early, before irreversible kidney damage takes hold. The safety of similar VEGFC gene therapy approaches has already been tested in human clinical trials for breast cancer, suggesting this type of treatment may be safe for people with diabetes following further research.