Chd8 haploinsufficiency impairs early brain development and protein homeostasis later in life.
Jessica A Jiménez, Travis S Ptacek, Alex H Tuttle and 4 others
PMID 33023670WHAT IT FOUND
In male mice with a loss-of-function Chd8 mutation, anxiety and digging tests were unchanged at 6 months, while reduced rearing and social novelty preference grew by 1 year.
Brain protein-handling pathways were lower at 1 year. This is mouse biology, not a therapy finding.
Key findings
01At birth, mutant mice had increased brain weight; at later ages, male mutants had lower body weight than controls.
02Behavioral differences in male mutant mice became stronger with age: rearing decreased at 6 months and was more evident at 12 months, and center time was significantly reduced at 12 months.
03In aged mutant mice, cortical pathways for unfolded protein response, endoplasmic reticulum stress, and chaperone-mediated protein folding were reduced, and phospho-S6 staining was reduced in piriform cortex.
STILL TO COME
How it was doneWhat they found
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What it does not show
This was a mouse study, not a human clinical trial, so it cannot show what a therapy does for patients. The main behavioral cohort had 8 wild-type and 8 mutant male mice, and the tube co-occupancy cohort had 12 wild-type and 10 mutant mice. Behavioral testing was mainly in male mice because most humans with CHD8 mutations are male, so female mice were not fully evaluated. Many gene expression changes were small, and the authors used pathway analysis rather than relying on single genes. No protein level validation was performed outside CHD8 itself, although phospho-S6 staining was used. It is unclear whether age-related gene changes are direct effects of CHD8 loss or consequences of early brain development. The mouse phenotypes did not match all previous Chd8 mouse lines, and overlap in differentially expressed genes was limited. The study did not assess human speech, occupational, or physical therapy outcomes, or any intervention.
Declared interests
The supplied metadata lists NIH extramural and non-U.S. government research support. The provided text does not include an author conflict-of-interest declaration.
The easy way to misread this
Do not read the mouse social novelty preference or reduced protein-handling pathways as evidence that a therapy helps people with CHD8 mutations. The study was done in mice, mainly males, with small groups and no clinical treatment outcomes.