Dopaminergic neurons preferentially accumulate mtDNA rearrangements

T Tania Arguello (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine) C Christian D. Alcalde Pretel (MD/PhD Program and Department of Cell and Systems Biology, University of Miami Miller School of Medicine) N Nadee Nissanka (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine) D Derek Van Booven (John P. Hussman Institute for Human Genomics and Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine) M Milena Pinto (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine) M Monica Rodriguez-Silva (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine) L Lise-Michelle Theard (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine) A Anthony J. Griswold (John P. Hussman Institute for Human Genomics and Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine) C Carlos T. Moraes (Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine)

Abstract

High levels of mitochondrial DNA (mtDNA) deletions have been described in the substantia nigra. However, the mechanisms involved are poorly understood. We found that transient expression of a mitochondrial targeted restriction endonuclease (mitoPstI) in mice leads to an accumulation of mtDNA rearrangements that involve both the PstI cleavage sites and unrelated specific regions of the mtDNA, including the MTERF1 binding site and the edge of the D-loop. This pattern of rearrangements after double-strand breaks supports the presence of recombination hotspots in the mtDNA. Transient expression of mitoPstI in dopaminergic neurons led to further accumulation of mtDNA rearrangements in dopaminergic neurons after expression was suppressed, a pattern that was not observed in glutamatergic neurons. This accumulation was also blunted when a mtDNA replisome factor was absent, suggesting that robust mtDNA replication is required for the accumulation of preexisting mtDNA rearrangements in dopaminergic neurons over time.

Article Details

Volume / Issue Vol. 123, Issue 29
Published July 21, 2026
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (9)

T

Tania Arguello

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine

C

Christian D. Alcalde Pretel

MD/PhD Program and Department of Cell and Systems Biology, University of Miami Miller School of Medicine

N

Nadee Nissanka

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine

D

Derek Van Booven

John P. Hussman Institute for Human Genomics and Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine

M

Milena Pinto

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine

M

Monica Rodriguez-Silva

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine

L

Lise-Michelle Theard

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine

A

Anthony J. Griswold

John P. Hussman Institute for Human Genomics and Dr. John T. Macdonald Foundation Department of Human Genetics, University of Miami Miller School of Medicine

C

Carlos T. Moraes

Department of Neurology and Cell and Systems Biology, University of Miami Miller School of Medicine