Expressions of hepatic genes, especially IGF-binding protein-1, correlating with serum corticosterone in microarray analysis

Abstract

Microarray technology was evaluated for usefulness in assessing relationships between serum corticosterone and hepatic gene expression. Nine pairs of female Swiss mice were chosen to provide a wide range of serum corticosterone ratios; cDNA microarray analysis (∼8000 genes) was performed on their livers. A statistical method based on calculation of 99% confidence intervals discovered 32 genes which varied significantly among the livers. Five of these ratios correlated significantly with serum corticosterone ratio, including tyrosine aminotransferase, stress-induced protein, pleiotropic regulator 1 and insulin-like growth factor-binding protein-1; the latter has a potential role in cancer development. Secondly, linear regression of gene expression vs corticosterone ratios was screened for those with r ≥ 0·8 (P<0·01), yielding 141 genes, including some known to be corticosterone regulated and others of interest as possible glucocorticoid targets. Half of these significant correlations involved data sets where no microarray ratio exceeded±1·5. These results showed that microarray may be used to survey tissues for changes in gene expression related to serum hormones, and that even small changes in expression can be of statistical significance in a study with adequate numbers of replicate samples.

Estrogen effects on cognition and hippocampal transcription in middle-aged mice

“…Thus, an EB dependent increase in neuroprotective genes may contribute to maintenance of hippocampal function with age. Some aging-EB responsive genes have been linked to premature aging (Tbl2, Il13ra1), transcriptional changes in the hippocampus of senescence-accelerated mice (Dusp12) (Meng et al, 1998;Kyng et al, 2003;Cheng et al, 2007), and aging in different organisms (Lass2) (Obeid and Hannun, 2003), or organs (Peli1) (Cheng et al, 2004;Chelvarajan et al, 2006). Some genes may be associated with biological markers of aging including altered lipid/ cholesterol metabolism (Abca2, Vldlr, Acsl5, Srebf1, Apoa1) (Foster, 2006), lipid composition (Ptdss2) (Giusto et al, 2002), mitochondrial function (Atp5g1, Aco2) (Poon et al, 2006), and structural changes (Ctsb) (Bednarski et al, 1997).…”

Growth retardation in pediatric Crohnʼs disease

“…46 It has been documented that local infusion of dexamethasone into the growth plate causes a local inhibition effect on longitudinal bone growth, 47 which might be mediated through local reduction of IGF-1 expression within the growth plate, 48 or by increasing expression of binding proteins. 12 Adding to the controversy, several of the larger studies have not found an independent effect of steroids on growth, especially with short-term or low-dose steroid treatment. 2,26,27,29 -30 Griffiths et al, 27 in the largest study published so far, found that the use of corticosteroids was associated with height retardation only after the first year of treatment, but this effect was not significant if corrected for disease severity.…”

“…IGFBP-1 expression is increased in states of insulopenia and starvation and by corticosteroids in a dose-dependent manner. 11,12 Factors that increase IGFBP-1 may decrease the availability of bioactive IGF-1.…”

Microarray in parasitic infections

“…A few recent applications include microbe identification,[1] tumor classification,[2] evaluation of the host cell response to pathogens, and analysis of the endocrine system. [3] Microarrays opened up an entire new world to researchers. No longer is one restricted to studying a unique single aspect of the host/pathogen relationship; instead one can explore a genome-wide view of this complex interaction.…”