Study of mitochondrial function in placental insufficiency

Abstract

Introduction: It has been suggested that mitochondria play a crucial role in sustaining pregnancy and foetal growth. The aim of the study was to assess the influence of mitochondrial functions and genetics on placental insufficiency diseases.

Methods: A total of 115 patients were recruited, subdivided into 74 placenta samples and 41 maternal blood samples: placental insufficiency diseases including intra uterine growth restriction (IUGR) (n = 35), preeclampsia (PE) (n = 13), IUGR associated to PE (PER) (n = 25); and controls (n = 42). Haplogroups were determined for all patients. Eighty-six placenta samples were studied for quantitative and qualitative analyses of mtDNA: IUGR (n = 25), PE (n = 1), PER (n = 18) and controls (n = 42). Sixteen placenta samples were selected for functional analysis: IUGR (n = 6), PER (n = 2) and controls (n = 8).

Results: Mitochondrial DNA copy numbers and rearrangements and haplogroup distribution were not significantly altered in the patient group. Enzyme activity and expression of respiratory chain complexes were also comparable between both groups.

Discussion: Our results do not argue in favour of a mitochondrial involvement in placental insufficiency, suggesting that the glycolytic pathway may represent a key energetic source in placental insufficiency diseases.

Keywords: Mitochondrial DNA haplogroups; Placenta; Placental insufficiency diseases; Respiratory chain; mtDNA.