Project description:A series of dual-channel gene expression profiles obtained using Rosetta/Merck Mouse TOE 75k microarrays was used to examine the sex-dependent and STAT5b-dependent differences in gene expression in adult mouse liver. This series is comprised of 4 pools of 3 randomly chosen independent wildtype male and female mouse liver cDNA samples and 4 pools of 3 randomly chosen independent STAT5b-deficient male and female mouse liver cDNA samples, totaling 16 pools. The pools were paired randomly to generate 4 comparisons of M-WT:F-WT, M-WT:M-KO, F-KO:F-WT, and F-KO:M-KO. Comparison of the set of sex-dependent genes with the set of genes responsive to the loss of STAT5b in males shows that 75% of the sex-specific genes were also regulated by STAT5b in males. Only 20% of the sex-specific genes retained sex-specificity in the absence of STAT5b, indicating a large role for STAT5b in sex-specific liver gene expression. Keywords: genetic knockout and sex response
Project description:Sex differences in liver gene expression are dictated by sex-differences in circulating growth hormone (GH) profiles. Presently, the pituitary hormone dependence of mouse liver gene expression was investigated on a global scale to discover sex-specific early GH response genes that might contribute to sex-specific regulation of downstream GH targets and to ascertain whether intrinsic sex-differences characterize hepatic responses to plasma GH stimulation. RNA expression analysis using 41,000-feature microarrays revealed two distinct classes of sex-specific mouse liver genes: genes subject to positive regulation (class-I) and genes subject to negative regulation by pituitary hormones (class-II). Genes activated or repressed in hypophysectomized (Hypox) mouse liver within 30-90min of GH pulse treatment at a physiological dose were identified as direct targets of GH action (early response genes). Intrinsic sex-differences in the GH responsiveness of a subset of these early response genes were observed. Notably, 45 male-specific genes, including five encoding transcriptional regulators that may mediate downstream sex-specific transcriptional responses, were rapidly induced by GH (within 30min) in Hypox male but not Hypox female mouse liver. The early GH response genes were enriched in 29 male-specific targets of the transcription factor Mef2, whose activation in hepatic stellate cells is associated with liver fibrosis leading to hepatocellular carcinoma, a male-predominant disease. Thus, the rapid activation by GH pulses of certain sex-specific genes is modulated by intrinsic sex-specific factors, which may be associated with prior hormone exposure (epigenetic mechanisms) or genetic factors that are pituitary-independent, and could contribute to sex-differences in predisposition to liver cancer or other hepatic pathophysiologies.
Project description:A series of dual-channel gene expression profiles obtained using Rosetta/Merck Mouse TOE 75k microarrays was used to examine the sex-dependent and STAT5b-dependent differences in gene expression in adult mouse liver. This series is comprised of 4 pools of 3 randomly chosen independent wildtype male and female mouse liver cDNA samples and 4 pools of 3 randomly chosen independent STAT5b-deficient male and female mouse liver cDNA samples, totaling 16 pools. The pools were paired randomly to generate 4 comparisons of M-WT:F-WT, M-WT:M-KO, F-KO:F-WT, and F-KO:M-KO. Comparison of the set of sex-dependent genes with the set of genes responsive to the loss of STAT5b in males shows that 75% of the sex-specific genes were also regulated by STAT5b in males. Only 20% of the sex-specific genes retained sex-specificity in the absence of STAT5b, indicating a large role for STAT5b in sex-specific liver gene expression. A pool of cDNA from 3 mice is Cy3-labeled and compared to another pool of cDNA from 3 mice that is Cy5-labeled. The pools are then dye-swapped and compared again. The two pairs of data are averaged together, the averages are normalized across the fluorescent reverse pairings, and the log2 value is reported for each average as well as the anti-log. This is replicated 3 times with independent pools of cDNA for each pair of conditions being compared. There are a total of 4 pairs of conditions compared for a grand total of 12 samples.
Project description:We identified genes expressed in mouse liver that are regulated by Cux2, a highly female-specific liver transcription factor whose expression is regulated by sex-dependent plasma GH patterns. Using siRNA to knockdown Cux2 expression in female liver, we show that female specific genes are predominantly repressed by Cux2 knockdown. In contrast, similar numbers of male-biased genes are repressed as are induced by Cux2 knockdown. A scrambled, non-specific siRNA was used as a control. (Published in: TL Conforto et al 2012, Mol Cell Biol. 2012, 32:4611-4627. PubMed PMID: 22966202; PMCID: PMC3486175)
Project description:We identified genes expressed in mouse liver that are regulated by Cux2, a highly female-specific liver transcription factor whose expression is regulated by sex-dependent plasma GH patterns. Using adenovirus to overexpress Cux2 (Adeno-Cux2) in male liver, we show that Cux2 represses ~35% of male-biased genes and induces/de-represses ~35% of female-biased genes. Adeno-CMV was used as a control for adenoviral infection. (Published in: TL Conforto et al 2012, Mol Cell Biol. 2012, 32:4611-4627. PubMed PMID: 22966202; PMCID: PMC3486175)
Project description:Microarray analysis of male and female CD-1 mouse liver was carried out at 3, 4, and 8 wk of age to elucidate developmental changes in gene expression from the pre-pubertal period to young adulthood. A large number of sex-biased and sex-independent genes showed significant changes during this developmental period. Notably, sex-independent genes involved in cell cycle, chromosome condensation, and DNA replication were down regulated from 3 wk to 8 wk, while genes associated with metal ion binding, ion transport and kinase activity were up regulated. A majority of genes showing sex differential expression in adult liver did not display sex differences prior to puberty, at which time extensive changes in sex-specific gene expression were seen, primarily in males. Thus, in male liver, 76% of male-specific genes were up regulated and 47% of female-specific genes were down regulated from 3 to 8 wk of age, whereas in female liver 67% of sex-specific genes showed no significant change in expression. In both sexes, genes up regulated from 3 to 8 wk were significantly enriched (p < E-76) in the set of genes positively regulated by the liver transcription factor HNF4α, as determined in a liver-specific HNF4α knockout mouse model, while genes down regulated during this developmental period showed significant enrichment (p < E-65) for negative regulation by HNF4α. Significant enrichment of the developmentally regulated genes in genes subject to positive and negative regulation by pituitary hormone was also observed. Nine sex-specific transcription factors showed pubertal changes in expression and may contribute to the developmental changes that onset after 3-4 wk. Overall, the observed changes in gene expression during postnatal liver development reflect the deceleration of liver growth and the induction of specialized liver functions, with widespread changes in sex-specific gene expression primarily occurring in male liver.
Project description:A series of dual-channel gene expression profiles obtained using Agilent Mouse TOE 75k microarrays was used to examine the sex-dependent and STAT5a-dependent differences in gene expression in adult mouse liver. This series is comprised of 3 randomly chosen independent male and female wildtype mouse liver cDNA samples and 3 randomly chosen independent male and female STAT5a-deficient mouse liver cDNA samples, totalling 12 samples. The samples were paired randomly to generate 4 comparisons of M-WT:F-WT, M-WT:M-KO, F-KO:F-WT, F-KO:M-KO. Comparison of the set of sex-dependent genes with the set of genes responsive to the loss of STAT5a in females shows a small group of the sex-specific genes were also regulated by STAT5a in females. These results indicate a role for STAT5a in female gene expression to a lesser degree than that shown for STAT5b in males. Keywords: genetic knockout and sex response