Amniotic Fluid Cells Proliferation in Normal and Down Syndrome Subjects

Down Syndrome/Trisomy 21 is the most common chromosomal anomaly, and it represents the most common congenital cause of infants’ intellectual disability. Subjects with this syndrome are affected by degenerative processes caused by accelerated aging or unknown ethyologies. In recent years, accumulating evidence revealed increased potential of amniotic fluid-derived stem cells to be used in regenerative therapy. Our aim was to assess differences in immunophenotype, cell morphology and proliferation of amniotic fluid cells from normal and Down Syndrome pregnancies using a quantitative cytometry approach. Results revealed the emergence of a population of small sized cells in Down Syndrome derived amniotic fluid cells that are readily visible upon microscopic inspection. Hence, the fluorescence–based quantitative image cytometry determinations showed a tendency of decrease in both cell and nuclei size in trisomy, with no significant modification in nuclei circularity, as measured following actin cytoskeleton and nuclei labeling. The propensity of Ki67 positive cells was found to be increased in Down Syndrome derived cells (48.92%) as compared to normal specimens (28.68%). However, cells in S and G2/M cell cycle phases decreased from 32.91% to 4.49% in diseased cells. Further studies are devoted to understanding the molecular basis of the observed differences in the proliferation ability of Down Syndrome amniotic cells, in order to evaluate the potential therapeutic effect of amniotic fluid stem cells for tissue regeneration in subjects with trisomy and to find correlations between amniotic cells phenotype and patient prognosis.