Transplanting healthy human brain support cells into adult mice with Huntington’s disease slowed motor and cognitive decline and extended lifespan, researchers have found.
The study suggests an alternative approach to treating Huntington’s – a hereditary condition that damages nerve cells – by replacing diseased glial cells rather than focusing solely on preserving neurons.
Researchers observed that even when transplants were carried out after symptoms had begun, the treatment restored normal gene activity in neurons and improved the connections between nerve cells.
The findings come from the University of Rochester Center for Translational Neuromedicine and offer new insight into the role of glial cells in disease progression, as well as the potential for cell-based therapies in adults already showing symptoms.
Steve Goldman is co-director of the centre and lead author.
He said: “Glia are essential caretakers of neurons.
“The restoration of healthy glial support—even after symptoms begin—could reset neuronal gene expression, stabilise synaptic function, and meaningfully delay disease progression.
“This study shifts the perspective on Huntington’s from a neuron-centric view to one that shows a critical role for glial pathology in driving synaptic dysfunction. It also tells us that the adult brain still has the capacity for repair when you target the right cells.”
Huntington’s disease is caused by a mutation in the huntingtin gene that produces an abnormal protein.
This leads to gradual damage in nerve cells, particularly in the striatum – a brain region involved in movement – and results in symptoms such as involuntary movements, cognitive decline and mood changes.
While the condition has traditionally been studied from a neuron-focused perspective, earlier work in Goldman’s lab has demonstrated that glial cells – once thought to merely support neurons – are key to regulating brain function. In Huntington’s, these cells become dysfunctional and may accelerate neuronal damage.
The researchers used R6/2 mice, a widely used model that mirrors motor and cognitive symptoms seen in human Huntington’s disease.
At five weeks old, when symptoms had just started, the mice received injections of human glial progenitor cells into their striata.
These are early-stage support cells that can develop into various types of glia.
The mice were tested on tasks involving coordination, movement, memory and anxiety.
Researchers also performed single-nucleus RNA sequencing to measure gene activity in neurons, and used a modified rabies virus to label and visualise neuron structures including dendrites (branches) and synapses (connection points).
Treated mice showed clear delays in symptom progression and lived several weeks longer than untreated mice.
The treatment restored the expression of genes linked to synapse function, and increased dendritic branching and spine density – both of which are typically reduced in Huntington’s.
Co-author Abdellatif Benraiss said: “Even though treatment began after symptoms appeared, significant improvements were still seen—highlighting the potential for adult intervention.”
The researchers believe glial cell transplants could become part of a wider treatment strategy, used either alone or in combination with approaches targeting the mutant huntingtin gene or replacing lost neurons.
Future studies will aim to refine delivery methods, dosage and timing.
