Ethanol Alters Proliferation and Differentiation of Normal and Chromosomally Abnormal Human Embryonic Stem Cell‐Derived Neurospheres

Abstract

Ethanol is a powerful substance and, when consumed during pregnancy, has significant psychoactive and developmental effects on the developing fetus. These abnormalities include growth retardation, neurological deficits, and behavioral and cognitive deficiencies, commonly referred to as fetal alcohol spectrum disorder. The effect of ethanol has been reported to affect cellular development on the embryonic level, however, not much is known about mutations contributing to the influence of ethanol. The purpose of our study was to determine if mutation contribute to changes in differentiation patterning, cell-cycle regulatory gene expression, and DNA methylation in human embryonic stem cells after ethanol exposure. We exposed human embryonic stem cells (with and without know DNA mutations) to a low concentration (20 mM) of ethanol and measured neurosphere proliferation and differentiation, glial protein levels, expression of various cell-cycle genes, and DNA methylation. Ethanol altered cell-cycle gene expression between the two cell lines; however, gene methylation was not affected in ether lines.

Gene expression signatures affected by alcohol-induced DNA methylomic deregulation in human embryonic stem cells

“…Furthermore, we have identified landscapes of molecular networks that are potentially deregulated by EtOH exposure through DNA methylomic alterations. This is in contrast to the recently reported lack of methylation changes after exposure of hESCs to 20 mM EtOH (Krishnamoorthy et al, 2013). Interestingly, their reported selective gene subsets are, for the most part, also unchanged in our study, whereas the much larger set of genes which do show methylation changes in our study are not reported by these authors.…”

Chromatin Switches during Neural Cell Differentiation and Their Dysregulation by Prenatal Alcohol Exposure

“…Low doses of alcohol have been shown to promote stem cell expansion, while higher concentrations slow proliferation [95,96,97,98,99]. Several cell culture studies indicate that alcohol exposure inhibits neurogenesis [100], while hastening neuronal differentiation [100,101]. During the neurogenic period, alcohol causes a decrease in a variety of neuronal populations including hippocampal CA1 pyramidal cells [102,103,104,105,106,107,108,109,110,111], cerebellar Purkinje cells [112,113,114,115], and cerebral cortical neurons [116,117].…”

“…These changes may be related to alcohol induction of pro-glutamatergic genes, such as Paired box 6 ( Pax6 ), Neurogenin 2 ( Neurog2 ), and Neurogenic Differentiation-1 ( Neurod1 ) and inhibition of pro-GABAergic Mammalian Achaete Scute Homolog-1 ( Ascl1 ) levels [100]. Additionally, prenatal alcohol exposure alters the distribution and morphology of neurons [101,129]. Ectopic distribution and density of neuronal synapses generated late in gestation have been reported [116,130,131,132,133,134].…”

Ethanol Inactivated Mouse Embryonic Fibroblasts Maintain the Self-Renew and Proliferation of Human Embryonic Stem Cells

“…Accordingly, it is reported that larger colonies of undifferentiated hESC exposed to 20 mM ethanol will increase apoptosis and decreased glial fibrillary acidic protein (GFAP) expression in later differentiation progress, indicating that ethanol reduced astrocyte differentiation potential[ 42 ]. There is also reported that 20 mM ethanol exposure altered the proliferation and differentiation of hESCs-derived neurospheres[ 43 ]. Recently, research showed that 1.0% (0.22M) ethanol exposure could affect the expression of key pluripotency markers in ESC, made the ESCs loss their pluripotency[ 44 ].…”