The Impact of Gestational Age on Targeted Amniotic Cell Profiling in Experimental Neural Tube Defects

Abstract

Purpose: The proportions of select stem cells in term amniotic fluid have been shown to correlate with the type and size of experimental neural tube defects (NTDs). We sought to determine the impact of gestational age upon this form of targeted amniotic cell profiling. Methods: Sprague-Dawley fetuses with retinoic acid-induced NTDs (n = 110) underwent amniotic fluid procurement at four time points in gestation. Samples were analyzed by flow cytometry for the presence of cells concomitantly expressing Nestin and Sox-2 (neural stem cells, aNSCs) and cells concomitantly expressing CD29 and CD44 (mesenchymal stem cells, aMSCs). Statistical analysis was by nonparametric Kruskal-Wallis ANOVA (p < 0.05). Results: There was a statistically significant impact of gestational age on the proportions of both aMSCs (p = 0.01) and aNSCs (p < 0.01) in fetuses with isolated spina bifida. No such impact was noted in normal fetuses (p > 0.10 for both cells), in isolated exencephaly (p > 0.10 for both cells), or in combination defects (p > 0.10 for both cells). Gestational age had no effect on aNSC/aMSC ratios. Conclusions: Targeted quantitative amniotic cell profiling varies with gestational age in experimental isolated spina bifida. This finding should be considered prior to the eventual translation of this diagnostic adjunct into the prenatal evaluation of these anomalies.

Clusters of amniotic fluid cells and their associated early neuroepithelial markers in experimental myelomeningocele: Correlation with astrogliosis

“…We also showed that these cells exist along with SOX-2 and nestin positive cells, GFAP positive astrocytes, and doublecortin positive neurons. Thus, the data presented here combined with previous reports [ 29 – 31 ] shows neural cells isolated from the AF in the setting of neural tube defects contain various populations of neuroepithelial cells.…”

“…Accordingly, AF-derived cells have emerged as a potential supportive strategy for prenatal diagnosis of neural tube defects. In studies of AF cells in neural tube defects, the emphasis was on detection of neural cells from AF and more recently the impact of gestational age on relative proportions of select populations of AF cells [ 31 ]. In our studies, we showed the presence of unique cluster-forming population of neuroepithelial cells in the AF of MMC fetuses at stages pathologically associated with spinal cord injury assessed by immunohistochemical examination of astrogliosis.…”

“…During gestation, amniotic fluid constitutes an important part of fetal environment and provides a source of cells for the prenatal diagnosis or therapy of developmental defects [ 24 ]. Although neural cells have been identified in the AF of fetuses with neural tube defects [ 25 – 28 ], a more comprehensive analysis of AF cell phenotypic profiling during the development of these defects has only recently started to be performed [ 29 – 31 ].…”

Transamniotic stem cell therapy: a novel strategy for the prenatal management of congenital anomalies

“…The fact that the amniotic fluid may be an accessible source of (autologous) NSCs relevant to the development of new therapies for spina bifida adds another facet to the TRASCET concept. In addition, recent studies suggest that this unique population of stem cells may also have diagnostic value in the setting of congenital NTDs, besides a potential therapeutic one (17,18). Certainly, the perspective of other disease-associated amniotic stem cells being eventually described, along with roles for such cells in select clinical scenarios, is now to be expected.…”

“…This finding supports the notion that the inherent biological activity of afMSCs constitutes a central underlying mechanism of defect coverage triggered by TRASCET, which may simply represent an augmentation of such activity via the large number of cells delivered. In fact, recent studies suggest that afMSCs may actually be consumed in the presence of NTDs (17,18). Although the ontogeny of afMSCs and placental MSCs remain to be fully elucidated, there is evidence that they actually could be the same cell, possibly with normal traffic between the amniotic and placental compartments (54)(55)(56).…”