The research was led by the Researchers at University of California San Diego School of Medicine. They reported that a single infusion of wild-type hematopoietic stem and progenitor cells (HSPCs) into a mouse model of Friedreich's ataxia (FA) restored the cellular damage caused by the degenerative disease. Transplantation of hematopoietic stem cells led to a potential therapeutic approach for the diseases that are incurable. The study findings are published online in Science Translational Medicine.

Friedreich's ataxia affects one in 50,000 Americans; it is an inherited and degenerative neuromuscular disorder. The motor function was initially impaired namely (gait and coordination). It causes scoliosis, heart disease, vision loss and diabetes while the cognitive function is not altered. On the progression of the disease, the person requires full-time use of a wheelchair.

Reduction in the mitochondrial protein called frataxin (FXN) expression due to a two mutated or abnormal copies of the FXN gene causes FA. Stephanie Cherqui, from the UC San Diego School of Medicine Department of Pediatrics and colleagues, used a transgenic mouse model. The mouse expressed two mutant human FXN transgenes and exhibited progressive neurological degeneration and muscle weakness.

Human hematopoietic stem and progenitor cells (HSPCs) are derived from bone marrow. They are used to replace or regenerate cells destroyed by a variety of diseases. In the earlier studies, it was shown that transplanting mouse HSPCs (wild-type or normal) resulted in the long-term eye, kidney, and thyroid preservation in a mouse model of cystinosis (genetic disorder).

In the current study, researchers transplanted wild-type HSPCs into an FA mouse model. The HSPCs engrafted and differentiated into macrophages in the mice's brain and spinal cord, wildtype FXN was transferred into neurons and muscle cells in these key regions.

The mouse model is not the perfect mirror of human FA. The disease progression is different, and pathology in mice is not fully known. The findings are encouraging and point toward a potential treatment for a disease, added Cherqui.

“Transplantation of wildtype mouse HSPCs essentially rescued FA-impacted cells,” said Cherqui. “Frataxin expression was restored. Mitochondrial function in the brains of the transgenic mice normalized and there was decreased skeletal muscle atrophy.”