Alcohol and endogenous aldehydes damage chromosomes and mutate stem cells

Area of Science:

• Molecular Biology
• Genetics
• Hematology

Background:

• Haematopoietic stem cells (HSCs) are crucial for blood renewal.
• Accumulated DNA damage in HSCs can lead to decline and malignancies.
• Acetaldehyde, an endogenous and alcohol-derived metabolite, is a source of DNA damage.

Purpose of the Study:

• To characterize DNA damage caused by acetaldehyde in HSCs.
• To investigate the mutational landscape and repair mechanisms of acetaldehyde-induced DNA damage.
• To determine the role of p53 in the response to aldehyde-induced DNA damage in HSCs.

Main Methods:

• Single HSC transplantation combined with whole-genome sequencing.
• Analysis of DNA damage, mutations, and chromosome rearrangements.
• Assessment of cell survival and genome instability in p53-deficient HSCs.

Main Results:

• Acetaldehyde causes DNA double-stranded breaks and chromosome rearrangements in HSCs.
• Damage is repaired via microhomology-mediated end-joining, leading to deletions and rearrangements.
• Deletion of p53 rescues HSC survival under aldehyde stress but does not alter mutation patterns.

Conclusions:

• Acetaldehyde is an endogenous source of stem cell genome mutation.
• DNA repair pathway choice and p53 response limit the transmission of aldehyde-induced mutations in HSCs.
• Understanding these mechanisms is vital for preventing alcohol-related hematologic malignancies.