In a further test of a novel theory that suggests autism is the consequence of abnormal cell communication, researchers at the University of California, San Diego School of Medicine report that an almost century-old drug approved for treating sleeping sickness also restores normal cellular signaling in a mouse model of autism, reversing symptoms of the neurological disorder in animals that were the human biological age equivalent of 30 years old.
The findings, published in the June 17, 2014 online issue of Translational Psychiatry, follow up on similar research published last year by senior author Robert K. Naviaux, MD, PhD, professor of medicine, pediatrics and pathology, and colleagues. Naviaux said the findings fit neatly with the idea that autism is caused by a multitude of interconnected factors: “Twenty percent of the known factors associated with autism are genetic, but most are not. It’s wrong to think of genes and the environment as separate and independent factors. Genes and environmental factors interact. The net result of this interaction is metabolism.”
Naviaux and colleagues have focused on a cellular signaling system linked to both mitochondrial function and to the cell’s innate immune function. Specifically, they have zeroed in on the role of nucleotides like adenosine triphosphate (ATP) and other signaling mitokines — molecules generated by distressed mitochondria. These mitokines have separate metabolic functions outside of the cell where they bind to and regulate receptors present on every cell of the body. Nineteen types of so-called purinergic receptors are known to be stimulated by these extracellular nucleotides, and the receptors are known to control a broad range of biological characteristics with relevance to autism, such as impaired language and social skills.
“Obviously correcting abnormalities in a mouse is a long way from a cure in humans, but we think this approach — antipurinergic therapy — is a new and fresh way to think about and address the challenge of autism.