Increase in short telomeres during the third trimester in human placenta

Area of Science:

• Reproductive biology
• Genetics
• Cellular aging

Background:

• Telomere shortening is implicated in cellular aging and has been proposed as a mechanism for initiating parturition.
• Previous studies in mice indicated an increase in very short telomeres with advancing gestational age.

Purpose of the Study:

• To investigate the hypothesis that the quantity of very short telomeres (<3 kilobase lengths) increases in human placental tissue as term gestation approaches.
• To explore the role of telomere shortening in the timing of human parturition.

Main Methods:

• Quantitative measurement of very short telomeres in placental tissue using a real-time polymerase chain reaction (qPCR) adaptation of the telomere restriction fragment technique.
• Analysis of placental tissue from 69 pregnant individuals, comparing term (mean gestational age 39.1 weeks) and preterm (mean gestational age 36.2 weeks) samples.

Main Results:

• A significant increase in very short telomeres was observed in term placentas compared to preterm placentas.
• Specifically, 500 bp telomeres increased 1.67-fold (p < 0.03), 1 kb telomeres increased 1.67-fold (p < 0.08), and 3 kb telomeres increased 5.20-fold (p < 0.001) in term placentas.
• These findings support the hypothesis linking telomere shortening at term to the initiation of parturition.

Conclusions:

• This study confirms a significant increase in very short telomeres in human placental tissue at term.
• The results support the hypothesis that telomere shortening at term contributes to the mechanism determining pregnancy duration and initiating parturition.