- Alzheimer's disease is a neurodegenerative disorder that often results in dementia.
- Scientists have studied the impact of combustion-derived nanoparticles (CDNPs) in the young brains.
- Highly oxidative, combustion nanoparticles could be a culprit hidden in plain sight in Alzheimer's disease.
The short-and long-term impact of airborne iron-rich strongly magnetic combustion-derived nanoparticles (CDNPs) present in the young brains were studied by a research team at the University of Montana, Universidad del Valle de Mexico, Instituto Nacional de Pediatria, Boise State and Universidad Nacional Autonoma de Mexico.
The research team documented the abundant combustion nanoparticles in neurons, glial cells, choroid plexus and neurovascular units of Mexico City children, teens and young adults who were exposed to concentrations above the US-EPA standards for fine particular matter by using transmission electron microscopy.
‘Highly oxidative, combustion-derived nanoparticles that could enter the brains could be a culprit hidden in plain sight in Alzheimer’s disease development.’
The residents in Mexico City have been exposed from conception to harmful neurotoxic air pollutants.
The study findings were published in the Journal of Alzheimer's Disease.
Impact of Tiny Particles into the Brain
The impact of these particles on the brain through the nasal and olfactory epithelium, the lungs, gastrointestinal system could be recognized by extensive alterations in the neuronal organelles that include mitochondria and the dendrites.
Due to the close contact of nanoparticles with neurofilaments, glial fibers and chromatin, the research team were more concerned about the potential to alter microtubule dynamics, accumulation and aggregation of unfolded proteins, mitochondrial dysfunction, altered calcium homeostasis, insulin signaling and epigenetic changes.
Key Markers of Alzheimer's Disease
The Mexico city children, teens, young adults were showing key markers of Alzheimer's disease.
- Hyperphosphorylated tau and amyloid plaques with significant brain and intrathecal neuroinflammation
- Dysregulated immune responses
- Breakdown of epithelial and endothelial barriers
- Damage to the neurovascular unit
- Brain accumulation of metals with combustion
However, the healthy young people could have olfaction deficits, dysregulation of feeding hormones, deficiencies in attention and short-term memory, and below-average scores in verbal, full-scale IQ when compared to age, gender, socioeconomic status which is matched along with low air pollution residents.
Overweight female teens carrying an allele of the apolipoprotein E (APOE) which is the most common genetic risk factor for AD have serious cognitive problem.
Dr. Lilian Calderon-Garciduenas, said, "In the context of serious continuous exposures to high concentrations of fine particulate matter (PM 2.5) and ozone, our current electron microscopy findings and the extensive literature associating air pollutants with brain damage, the issue of who is at risk of neurodegeneration at an early age should be an urgent public health concern."
"The effects of poverty, urban violence and urban stress on impaired cognitive skills are also very important for the developing brain and can't be ignored. We know gender, BMI, and APOE influence children's cognitive responses to air pollution."
Combustion-derived Nanoparticles in Child's Brain
The research team has found that the problem of having combustion-derived nanoparticles in the child's developing brains are very serious.
The particles are omnipresent and are present in high concentrations in children as young as three years old.
These could contain transition neurotoxic metals and can cause brain damage in key organelles.
Dr. Calderon - Garciduenas emphasized, said, "The predominant combustion particles in young brains have properties that enable them to cause oxidative damage because these nanoparticles are capable of crossing all barriers. No barrier is spared."
Angélica González-Maciel added, "People with children and teens struggling in school and facing a significant increase of violence in school, streets, parks, and public transportation are deeply concerned about the impact these particles have on children's behavioral patterns and academic performance and parents question what they can do to protect their families".
Even though there was driving restriction policies were clearly ineffective. Millions of Mexico City residents when continued to be exposed to very unhealthy concentrations of both PM 2.5 and ozone, which are known risk factors for Alzheimer's disease.
Dr. Calderon-Garciduenas, said, "Our results highlight the urgent need for significantly decreasing the concentrations of fine particulate matter and ozone in Mexico City and the adjacent polluted states. Multidisciplinary intervention strategies could provide paths for prevention or amelioration of air pollution targeted cognitive deficits and possible long-term AD progression."
The combined effects of combustion-derived nanoparticles, poor nutrition, obesity, metabolic syndrome, urban stress, lower brain and cognitive reserves, and living in a highly-polluted city could result in the acceleration of neurodegenerative changes among uncertain young brains.
Finally, to conclude the research team found that highly oxidative, combustion nanoparticles that could enter the young developing brains are the main culprit hidden in the plain sight in Alzheimer's disease development. This could be a serious health issue with social and economic consequences.
Further research should be aimed to identify and protect high-risk patients. However, it is still not happening.
- Angélica González-Maciel, Rafael Reynoso-Robles, Ricardo Torres-Jardón, Partha S. Mukherjee, Lilian Calderón-Garcidueñas. Combustion-Derived Nanoparticles in Key Brain Target Cells and Organelles in Young Urbanites: Culprit Hidden in Plain Sight in Alzheimer's Disease Development. Journal of Alzheimer's Disease, (2017); DOI: 10.3233/JAD-170012