Reduced mtDNA Copy Number Links to Vascular Calcification and Restores After Transplantation

• Published in: Cells (Basel, Switzerland) Vol. 14; no. 12; p. 917
• Main Authors: Schwarz, Angelina, Qureshi, Abdul Rashid, Hernandez, Leah, Wennberg, Lars, Wernerson, Annika, Kublickiene, Karolina, Shiels, Paul G., Filograna, Roberta, Stenvinkel, Peter, Witasp, Anna
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.06.2025; MDPI
• Subjects: Adult; Age; Aged; Aging; Analysis; Blood pressure; Body mass index; CAC score; Calcification; Calcification (ectopic); Cancer; Cardiovascular diseases; Case-Control Studies; Cholesterol; Chronic kidney failure; CKD; Copy number; Coronary vessels; Development and progression; Diabetes; DNA Copy Number Variations - genetics; DNA, Mitochondrial - genetics; early vascular calcification; Female; Genes; Genetic testing; Health aspects; Hemoglobin; High density lipoprotein; Homeostasis; Humans; Inflammation; Kidney diseases; Kidney Transplantation; Kidneys; Male; Middle Aged; Mitochondria; Mitochondrial DNA; Mortality; mtDNA copy number; Oxidative phosphorylation; Patients; Phosphorylation; Renal Insufficiency, Chronic - genetics; renal transplantation; Senescence; Therapeutic targets; Transplantation; Type 2 diabetes; United States; Vascular Calcification - genetics; Veins & arteries; United States; United States > US; Germany; CAC score; early vascular calcification; CKD; mtDNA copy number; renal transplantation
• DOI: 10.3390/cells14120917
• ISSN: 2073-4409

Patients with chronic kidney disease (CKD) face an increased risk of early vascular aging, progressive vascular calcification, and premature death. With increasing age, mitochondrial function and mitochondrial DNA copy number (mtDNA-cn) decline. This has been identified as an independent predictor of frailty and mortality in cardiovascular diseases (CVDs) and cancer. However, the relationship between mtDNA-cn and vascular calcification in the context of a uremic milieu remains ambiguous. We hypothesize that a lower mtDNA-cn is associated with medial calcification, as both are linked to impaired vascular health and accelerated aging. mtDNA-cn was analyzed in 211 CKD5 patients undergoing renal transplantation (RTx) and 196 healthy controls using quantitative PCR (qPCR) for three mtDNA genes (mtND1, mtND4, and mtCOX1) and single-locus nuclear gene hemoglobin beta (HbB). In 32 patients, mtDNA-cn was also quantified one year after RTx. The association between mtDNA-cn and vascular calcification scores, circulatory cell-free (ccf) mtDNA in plasma, and the surrogate marker of biological aging (skin autofluorescence) and CVD risk was assessed. mtDNA-cn was significantly lower in CKD5 patients than in controls and correlated with biological age, vascular calcification, and CVD risk. One year after RTx there was a significant recovery of mtDNA-cn in male patients compared to baseline levels. mtDNA-cn and ccf-mtDNA were inversely correlated. This prospective study provides novel insights into the link between low mtDNA-cn and vascular aging. It demonstrates that RTx restores mtDNA levels and may improve oxidative phosphorylation capacity in CKD. Further investigation is warranted to evaluate mtDNA as a biologically relevant biomarker and a potential therapeutic target for early vascular aging in the uremic environment.