Objective: Telomeres are DNA sequence repeats of TTAGGG, located at the end of the chromosomes, stabilize and protect them from fusion and degradation. Telomeres are progressively shortened with each mitotic cycle and also by environmental factors until genetic instability and cellular senescence occur. We evaluated telomeres length in placentas from pregnancies complicated with intra uterine growth restriction (IUGR) as part of the mechanism of placental dysfunction in IUGR.
Methods: Placental biopsies derived from 16 pregnancies complicated with IUGR and from 13 gestational age matched placentas from uncomplicated pregnancies as control. Placental biopsies were subjected to a fluorescence-in-situ protocol (DAKO) to determine telomere fluorescence intensity and number, in trophoblasts, using a manual and a novel computer assisted techniques. Immunohistochemistry was performed to detect hTERT, the catalytic unit of telomerase, which elongates telomeres. To rule out aneuploidy as a reason for shortened telomeres we used fluorescence-in-situ-hybridization for chromosomes 16, 18, X and y.
Results: We found that the number and intensity of telomeres staining was significantly lower in the IUGR placentas as well as the expression of hTERT, compared to the controls. No aneuploidy was detected for the chromosomes checked in either of the placental biopsies.
Conclusions: IUGR placentas have shortened telomeres. Our findings implicate short telomeres as a part of early senescence and placental dysfunction in IUGR placentas regardless the ploidity
of the cells.
Tal Biron-Shentala,d, Rebeka Sukenik Halevi, Lilacha,d Goldberg-Bittmanb,c, Devora Kidrond, Moshe D. Fejgina,b,d, Alisa Amielb,c
aOBGYN department, Meir Medical Center, bGenetic Institute, Meir Hospital, Kfar-Saba, cFaculty of Life Science, Bar-Ilan University, Ramat Gan, dSackler School of Medicine, Tel Aviv University