RESUMO
INTRODUCTION: The intrauterine environment, including the placenta, is influenced by a variety of factors, among which is diabetes during pregnancy. These factors can affect lifetime morbidity. Senescence is a state of cellular metabolic arrest, known to be correlated with age-related diseases and is usually accompanied by short telomeres. This study evaluated telomere characteristics in placentas and in cord blood from term pregnancies complicated by uncontrolled diabetes mellitus. METHODS: Placental biopsies and cord blood were collected from 16 pregnancies with poorly controlled diabetes and from 16 healthy controls. Senescence-associated heterochromatin foci (SAHF) and senescence-associated ß-galactosidase (SAß-Gal) staining were evaluated. Apoptosis was evaluated using tunel staining. Telomere length and aggregate formation were assessed in placentas and in cord blood using Q-FISH. RESULTS: Increased SAHF (19.28% ± 7.93 vs. 7.78% ± 5.31, P < 0.001) and SAß-Gal (7.1% ± 1.32 vs. 0.8% ± 0.41, P < 0.001), but not apoptosis were present in placentas from diabetic pregnancies compared to controls. Higher percentage of trophoblasts with short telomeres (24.42% ± 12.6 vs. 4.92% ± 6.4, P = 0.013) and noticeably more aggregate formation (2.75% ± 1.14 vs. 0.62% ± 0.87, P < 0.001) were observed in diabetic placentas compared to controls. These differences were not observed in cord blood samples. DISCUSSION: Poorly controlled diabetes is related to increased senescence and shorter telomeres in placentas. Those findings may partially explain increased long-term, related morbidity.
