Study confirms mitochondrial deficits in children with autism

May 8, 2014 by Phyllis Brown
autism
Quinn, an autistic boy, and the line of toys he made before falling asleep. Repeatedly stacking or lining up objects is a behavior commonly associated with autism. Credit: Wikipedia.

Children with autism experience deficits in a type of immune cell that protects the body from infection. Called granulocytes, the cells exhibit one-third the capacity to fight infection and protect the body from invasion compared with the same cells in children who are developing normally.

The cells, which circulate in the bloodstream, are less able to deliver crucial infection-fighting oxidative responses to combat invading pathogens because of dysfunction in their tiny energy-generating organelles, the mitochondria.

The study is published online in the journal Pediatrics.

"Granulocytes fight cellular invaders like bacteria and viruses by producing highly reactive oxidants, toxic chemicals that kill microorganisms. Our findings show that in children with severe autism the level of that response was both lower and slower," said Eleonora Napoli, lead study author and project scientist in the Department of Molecular Biosciences in the UC Davis School of Veterinary Medicine. "The granulocytes generated less highly reactive oxidants and took longer to produce them."

The researchers also found that the mitochondria in the granulocytes of children with autism consumed far less oxygen than those of the typically developing children—another sign of decreased mitochondrial function.

Mitochondria are the main intracellular source of , which are very reactive and can harm cellular structures and DNA. Cells can repair typical levels of oxidative damage. However, in the children with autism the cells produced more free radicals and were less able to repair the damage, and as a result experienced more oxidative stress. The free radical levels in the blood cells of children with autism were 1 ½ times greater than those without the disorder.

The study was conducted using blood samples of children enrolled in the Childhood Risk of Autism and the Environment (CHARGE) Study and included 10 children with severe autism age 2 to 5 and 10 age-, race- and sex-matched children who were developing typically.

In an earlier study the research team found decreased mitochondrial fortitude in another type of immune cell, the lymphocytes. Together, the findings suggest that deficiencies in the cells' ability to fuel brain neurons might lead to some of the cognitive impairments associated with autism. Higher levels of also might contribute to autism severity.

"The response found among mirrors earlier results obtained with lymphocytes from with severe autism, underscoring the cross-talk between energy metabolism and response to oxidative damage," said Cecilia Giulivi, professor in the Department of Molecular Biosciences in the UC Davis School of Veterinary Medicine and the study's senior author.

"It also suggests that the immune response seems to be modulated by a nuclear factor named NRF2," that controls antioxidant response to environmental factors and may hold clues to the gene-environment interaction in , Giulivi said.

Explore further: Black, Hispanic children with autism more likely to regress than whites

Related Stories

Black, Hispanic children with autism more likely to regress than whites

May 6, 2014
Some children with autism appear to be developing normally when they are very young. They babble or even talk, make eye contact with their parents, and crawl and walk on schedule. Then suddenly, these skills seem to vanish.

Dog ownership benefits families of children with autism, researcher finds

April 14, 2014
Many families face the decision of whether to get a dog. For families of children with autism, the decision can be even more challenging. Now, a University of Missouri researcher has studied dog ownership decisions in families ...

Motor skill deficiencies linked to autism severity in new research

April 24, 2014
(Medical Xpress)—An Oregon State University researcher has found a relationship between motor skill deficiencies and the severity of the symptoms of autism spectrum disorder in very young children.

Diagnosing and treating autism

April 18, 2014
April is National Autism Awareness Month. The Child Development Clinic at Children's Hospital of Richmond at VCU (CHoR) provides comprehensive assessment for pediatric patients with developmental delays or disabilities, including ...

Study shows gene defect's role in autism-like behavior

August 10, 2012
Scientists affiliated with the UC Davis MIND Institute have discovered how a defective gene causes brain changes that lead to the atypical social behavior characteristic of autism. The research offers a potential target for ...

Recommended for you

Late-breaking mutations may play an important role in autism

July 17, 2017
A study of nearly 6,000 families, combining three genetic sequencing technologies, finds that mutations that occur after conception play an important role in autism. A team led by investigators at Boston Children's Hospital ...

Females with autism show greater difficulty with day-to-day tasks than male counterparts

July 14, 2017
Women and girls with autism may face greater challenges with real world planning, organization and other daily living skills, according to a study published in the journal Autism Research.

Researchers investigate possible link between carnitine deficiency and autism

July 13, 2017
Researchers are always looking for new clues to the causes of autism, with special emphasis on prevention or treatment. At Baylor College of Medicine, Dr. Arthur Beaudet has been following clinical and genetic clues in patients ...

How children look at mom's face is influenced by genetic factors and altered in autism

July 12, 2017
New research has uncovered compelling evidence that genetics plays a major role in how children look at the world and whether they have a preference for gazing at people's eyes and faces or at objects.

Oxytocin improves social abilities in some kids with autism, study finds

July 10, 2017
Children with autism showed improved social behavior when treated with oxytocin, a hormone linked to social abilities, according to a new study by researchers at the Stanford University School of Medicine. Children with low ...

Possible early diagnosis of autism spectrum disorder

June 29, 2017
Measuring a set of proteins in the blood may enable earlier diagnosis of autism spectrum disorder (ASD), according to a study from the Peter O'Donnell Jr. Brain Institute at UT Southwestern Medical Center.

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

c_j_bmet
not rated yet May 09, 2014
I am having a problem understanding this article. It appears that there is contradictory information in this article. In one paragraph the article states the following :

"Granulocytes fight cellular invaders like bacteria and viruses by producing highly reactive oxidants, toxic chemicals that kill microorganisms. Our findings show that in children with severe autism the level of that response was both lower and slower," said Eleonora Napoli,

Another paragraph contradicts that information by stating the following: Mitochondria are the main intracellular source of oxygen free radicals, which are very reactive and can harm cellular structures and DNA. Cells can repair typical levels of oxidative damage. However, in the children with autism the cells produced more free radicals and were less able to repair the damage, and as a result experienced more oxidative stress.

So does the mitochondria in the Granulocytes in children with Autism produce to much free radicals or to little?
Rob
not rated yet May 09, 2014
I am not a cell biologist, but I think there is a difference between the oxidants that kill bacteria and the oxygen free radicals ( which is also an oxidant but free radicals don't travel very far before reacting with something).

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.