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Updated: Mar 8, 2026
Measuring Single-Cell Mitochondrial DNA Copy Number and Heteroplasmy Using Digital Droplet Polymerase Chain Reaction
Published on: July 12, 2022
Liver Mitochondrial DNA Copy Number and Deletion Levels May Contribute to Nonalcoholic Fatty Liver Disease
Sharareh Kamfar1, Seyed Moayed Alavian2, Massoud Houshmand3
1Department of Molecular Medicine and Genetics, School of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran; Research Center for Molecular Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran.
Background:
There is growing evidence that deficiencies observed in the mitochondrial DNA (mtDNA) functions could play an important role in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). We hypothesized that genetic variations in mtDNA could affect the mitochondrial function and contribute to the NAFLD susceptibility.
Objectives:
In this study, the possible association of the mtDNA copy number and 4,977-bp deletion levels with NAFLD susceptibility in a sample of Iranian population was evaluated.
Methods:
This case-control study included 43 NAFLD patients and 20 control subjects. Genomic DNA was extracted from fresh liver tissue samples by using a DNA isolation kit. The mtDNA copy number and mtDNA deletion levels were measured by quantitative real-time PCR and multiplex PCR.
Results:
The relative expression of mtDNA copy number was 3.7 fold higher in NAFLD patients than healthy controls (P < 0.0001). The results remained significant after adjustment for age, BMI, and gender (P = 0.02). In addition, the mtDNA copy number was 4.3 (P < 0.0001) and 3.2-fold (P < 0.0001) higher in nonalcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) patients than healthy controls, respectively. Finally, the results showed that the 4,977-bp deletion is not detected in any of liver tissue samples obtained from the 20 control subjects whereas 8 out of 43 NAFLD patients (18.6%) showed the 4,977 -bp deletion in their liver tissues (P = 0.039).
Conclusions:
This study indicated an association between mtDNA content in the liver tissue and NAFLD susceptibility that may be a consequence of compensatory response to the cumulative exposures to oxidative damage.
