Ο ρόλος της λεπτίνης και της συγκυτίνης στη λειτουργία του πλακούντα

Abstract

Aim: i) to study the effect of leptin upon proteins involved in the transportation of fatty acids throught the human placenta (FAT/ CD36 και cFABPs) ii) to study the expression of syncytin 1 and 2 and inter- correlate their expression γ) to study the effect of leptin upon expression of syncytin 1 and 2. Materials and methods: a total of 77 samples of trophoblastic tissue were used after chorionic villous sampling (CVS). Mean gestational age at sampling was 12+5 weeks (min= 11+0 weeks, max= 14+1 weeks, stdev= 0.89). The specimens were either used promptly after sampling or cultured to isolate total RNA or proteins. In a number of specimens forskolin (a substance that induces the differentiation of cytotrophoblasts in syncytiotrophoblasts) was added and the expression of the probed molecules was evaluated. Results: Main results (concisely presented) include i) when leptin was added in trophoblastic cell cultures, there was a statistically significant increase at the expression of RNA transcripts of the short form of leptin receptor (Ob- Ra), ii) when leptin was added in trophoblastic cell cultures, there was a statistically significant decrease at the expression of RNA transcripts of the long form of leptin receptor (Ob- Rb), iii) despite the presence of RNA transcripts, no expression of the H- FABP protein was noted, iv) no protein or RNA transcripts expression was noted for L-FABP, v) leptin, when added in trophoblastic cell cultures, increases statistically significantly the expression of the FAT/CD36 protein, vi) in fresh trophoblastic tissue, a cytoplasmic pool of FAT/CD36 mebrane protein was noted, vii) when added in trophoblastic cell cultures, forskolin causes an increase in the expression of RNA transcripts of syncytin 1, viii) when added in trophoblastic cell cultures, forskolin causes a decrease in the expression of RNA transcripts of syncytin 2, ix) when added in trophoblastic cell cultures, leptin causes an increase in the expression of RNA transcripts of syncytin 1, viii) when added in trophoblastic cell cultures, leptin causes a decrease in the expression of RNA transcripts of syncytin 2. Conclusions: leptin effect upon proteins involved in fatty acids transportation through the placenta was noted. Moreover, the presence of a cytoplasmic pool of FAT/CD36 was demonstrated, similarly to other tissues such as the muscular where it serves in case of an acute need of fatty acids transportation. Despite published results, we failed to demonstrate the expression of cytoplasmic fatty acids binding proteins. Differentiation of cytotrophoblast to syncytiotrophoblast increases syncytin 1 but decreases syncytin 2, thus making possible a theory of interplaying of syncytin 1 and 2 during placentation phenomena. Leptin has a similar effect upon syncytin biomolecules, thus pointing to its possible participation in the regulatory mechanism.