Expression Profiling of Neural Cells Reveals Specific Patterns of Ethanol-Responsive Gene Expression

Abstract

Adaptive changes in gene expression are thought to contribute to dependence, addiction and other behavioral responses to chronic ethanol abuse. DNA array studies provide a nonbiased detection of networks of gene expression changes, allowing insight into functional consequences and mechanisms of such molecular responses. We used oligonucleotide arrays to study nearly 6000 genes in human SH-SY5Y neuroblastoma cells exposed to chronic ethanol. A set of 42 genes had consistently increased or decreased mRNA abundance after 3 days of ethanol treatment. Groups of genes related to norepinephrine production, glutathione metabolism, and protection against apoptosis were identified. Genes involved in catecholamine metabolism are of special interest because of the role of this pathway in mediating ethanol withdrawal symptoms (physical dependence). Ethanol treatment elevated dopamine beta-hydroxylase (DBH, EC 1.14.17.1) mRNA and protein levels and increased releasable norepinephrine in SH-SY5Y cultures. Acute ethanol also increased DBH mRNA levels in mouse adrenal gland, suggesting in vivo functional consequences for ethanol regulation of DBH. In SH-SY5Y cells, ethanol also decreased mRNA and secreted protein levels for monocyte chemotactic protein 1, an effect that could contribute to the protective role of moderate ethanol consumption in atherosclerotic vascular disease. Finally, we identified a subset of genes similarly regulated by both ethanol and dibutyryl-cAMP treatment in SH-SY5Y cells. This suggests that ethanol and cAMP signaling share mechanistic features in regulating a subset of ethanol-responsive genes. Our findings offer new insights regarding possible molecular mechanisms underlying behavioral responses or medical consequences of ethanol consumption and alcoholism.

Chronic ethanol exposure induces an N‐type calcium channel splice variant with altered channel kinetics

“…Chronic exposure of neuronal cells to ethanol increases the abundance of mRNA for several other genes, including the heat shock protein HSC70 [17], the glucose regulated proteins GRP78 and GRP94 [18], dopamine b-hydroxylase [19,20], glial fibrillary acidic protein [20], the a 2 adrenergic receptor [21] and the delta opioid receptor [22]. In none of these studies were changes in splice variants examined.…”

Neurogenetic studies of alcohol addiction

“…However, many useful findings were carefully documented (for a review, see Reilly et al 2001). Early studies used banked tissue from human brain to compare alcoholics and controls (Lewohl et al 2000) or cultured cells to which alcohol was applied ( Thibault et al 2000). With the advent of gene chip technologies, it became possible to survey nearly the entire genome for expression differences, and some similarities emerged between microarray analyses and earlier studies (Lewohl et al 2000;Liu et al 2006).…”

Glutathione S‐Transferase 8‐8 Expression Is Lower in Alcohol‐Preferring Than in Alcohol‐Nonpreferring Rats

“…TOGA, which identifies differential expression of both known genes and 3′ expressed sequence tags (ESTs) (Lockhart and Barlow, 2001;Sutcliffe et al, 2000), identified rat glutathione S-transferase 8-8 (rGST 8-8) as one of the genes differentially expressed between iP and iNP. rGST 8-8 was selected for further investigation because (1) it was located near a QTL for alcohol preference identified in an iP × iNP F2 population that is syntenic with a QTL region for alcohol preference identified in the mouse (Belknap and Atkins, 2001;Phillips et al, 1998), (2) the expression difference between iP and iNP was notable, and (3) alcohol consumption induces the expression of GSTs (Schnellmann et al, 1984;Thibault et al, 2000).…”

“…From this data set, 28 that exhibited 2-fold or greater change in expression were prioritized on the basis of their expression pattern and function reported in the literature (Liang et al, 2003;Spence et al, 2004). rGST 8-8 was selected to characterize further because of its chromosomal location in the mouse, the role that it plays in neuroprotection, and the effect that alcohol consumption has on inducing expression of GSTs (Schnellmann et al, 1984;Thibault et al, 2000). A decrease in rGST 8-8 expression was observed in the iP compared with the iNP rats in all four dissected regions, with the cortex exhibiting the lowest fold change (2.9) and the striatum having the highest fold change (4.8; Table 1).…”

“…TOGA, which identifies differential expression of both known genes and 3′ expressed sequence tags (ESTs) (Lockhart and Barlow, 2001;Sutcliffe et al, 2000), identified rat glutathione S-transferase 8-8 (rGST 8-8) as one of the genes differentially expressed between iP and iNP. rGST 8-8 was selected for further investigation because (1) it was located near a QTL for alcohol preference identified in an iP × iNP F2 population that is syntenic with a QTL region for alcohol preference identified in the mouse (Belknap and Atkins, 2001;Phillips et al, 1998), (2) the expression difference between iP and iNP was notable, and (3) alcohol consumption induces the expression of GSTs (Schnellmann et al, 1984;Thibault et al, 2000).Glutathione S-transferases (GSTs) are a large family of multifunctional proteins involved in transport, biosynthesis of endogenous compounds, and disposition of exogenous toxicant compounds. GST isoenzymes have been categorized into eight classes: GSTA, GSTM, GSTP, GSTS, GSTT, GSTZ, GSTK, and GSTO (Board et al, 1997(Board et al, , 2000Meyer et al, 1991;Hayes and Pulford, 1995;Pemble et al, 1996).…”