Project description:To confirm the effect of Bcl6 on the liver sex difference, we performed the gene expression analysis in male and female wild type mice and male and female liver specific Bcl-6 deficient mice.
Project description:To confirm the effect of Bcl6 on the liver sex differrence, we performed the gene expression analysis in male and female wile type mice and male and female liver specific Bcl-6 deficient mice.
Project description:Sex-dependent pituitary growth hormone (GH) secretory patterns determine the sex-biased expression of >1,000 genes in mouse and rat liver, affecting lipid and drug metabolism, inflammation and disease. A fundamental biological question is how robust differential expression can be achieved for hundreds of sex-biased genes simply based on the GH input signal pattern: pulsatile GH stimulation in males vs. near-continuous GH exposure in females. STAT5 is an essential transcriptional mediator of the sex-dependent effects of GH in the liver, but the mechanisms that underlie its sex-dependent actions are obscure. Here we elucidate the dynamic, sex-dependent binding of STAT5 and the GH/STAT5-regulated repressor BCL6 to mouse liver chromatin, revealing the counteractive interplay between these two regulators of liver sex-specificity. Our findings establish a close correlation between sex-dependent STAT5 binding and sex-biased target gene expression. Moreover, sex-dependent STAT5 binding correlated positively with sex-biased DNase hypersensitivity and H3-K4me1 and H3-K4me3 (activating) marks, correlated negatively with sex-biased H3-K27me3 (repressive) marks, and was associated with sex-differentially enriched motifs for HNF6/CDP factors. Importantly, BCL6 binding was preferentially associated with repression of female-biased STAT5 targets in male liver. Furthermore, BCL6 and STAT5 common targets but not BCL6 unique targets showed strong enrichment for lipid and drug metabolism. These findings provide a comprehensive, genome-wide view of the mechanisms whereby these two GH-regulated transcription factors establish and maintain sex differences affecting liver physiology and disease. The approaches used here to characterize sex-dependent STAT5 and BCL6 binding can be applied to other condition-specific regulatory factors and binding sites and their interplay with co-operative chromatin-binding factors.
Project description:Sex-dependent pituitary growth hormone (GH) secretory patterns determine the sex-biased expression of >1,000 genes in mouse and rat liver, affecting lipid and drug metabolism, inflammation and disease. A fundamental biological question is how robust differential expression can be achieved for hundreds of sex-biased genes simply based on the GH input signal pattern: pulsatile GH stimulation in males vs. near-continuous GH exposure in females. STAT5 is an essential transcriptional mediator of the sex-dependent effects of GH in the liver, but the mechanisms that underlie its sex-dependent actions are obscure. Here we elucidate the dynamic, sex-dependent binding of STAT5 and the GH/STAT5-regulated repressor BCL6 to mouse liver chromatin, revealing the counteractive interplay between these two regulators of liver sex-specificity. Our findings establish a close correlation between sex-dependent STAT5 binding and sex-biased target gene expression. Moreover, sex-dependent STAT5 binding correlated positively with sex-biased DNase hypersensitivity and H3-K4me1 and H3-K4me3 (activating) marks, correlated negatively with sex-biased H3-K27me3 (repressive) marks, and was associated with sex-differentially enriched motifs for HNF6/CDP factors. Importantly, BCL6 binding was preferentially associated with repression of female-biased STAT5 targets in male liver. Furthermore, BCL6 and STAT5 common targets but not BCL6 unique targets showed strong enrichment for lipid and drug metabolism. These findings provide a comprehensive, genome-wide view of the mechanisms whereby these two GH-regulated transcription factors establish and maintain sex differences affecting liver physiology and disease. The approaches used here to characterize sex-dependent STAT5 and BCL6 binding can be applied to other condition-specific regulatory factors and binding sites and their interplay with co-operative chromatin-binding factors. Mouse livers were excised from individual male and female mice killed at either a peak of STAT5 binding activity, or during the growth hormone (GH) interpulse interval, when STAT5 activity is either low (females) or essentially undetectable (males). Sonicated, cross-linked liver nuclear chromatin was then used to identify STAT5 binding sites by ChIP-Seq.
Project description:Animal models are important tools in scientific research, whereas the animals used are usually single-sex instead of mixed-sex in the experimental design. To better understand the effect of sex difference, we compared several phenotypes between male and female C57BL/6 mice, including behavioral tests, plasma corticosterone levels, adult neurogenesis, and RNA-seq. The experiments were performed under non-stressed and chronic-stressed conditions, respectively. Overall, our results showed several differences between male and female mice in sensorimotor performance while little difference was found in anxiety, depression, learning, and memory. We did not observe a significant difference in adult neurogenesis. There was a sex difference in plasma corticosterone levels under chronic stress conditions, either in 30 min after the restraint stress or after 60min of the recovery. Yet, the corticosterone levels were equivalent between the sexes under non-stressed conditions at any time point. Furthermore, the results of RNA-seq identified the differential expression genes between male and female mice under non-stressed or chronic-stressed conditions.
Project description:A series of dual-channel gene expression profiles obtained using Rosetta/Agilent Whole Mouse Genome oligonucleotide microarrays, 4 x 44K format, was used to identify sex-dependent and HNF4alpha-dependent differences in gene expression in adult mouse liver. This series is comprised of four sex-genotype combinations: adult male wild-type liver (M-WT), adult female wild-type liver (F-WT), adult male liver-specific HNF4alpha knockout liver (M-KO) and adult female liver-specific HNF4alpha knockout liver (F-KO). Four pools, each comprised of 4 randomly selected individual liver RNAs, were prepared for each sex-genotype combination. The pools were paired randomly to generate 4 separate experimental comparisons: M-WT:F-WT (first array comparison), M-WT:M-KO (second array comparison), F-WT:F-KO (third array comparison), and M-KO:F-KO (fourth array comparison). A total of 4994 HNF4alpha-dependent genes were identified, of which ~1000 fewer genes responded to the loss of HNF4alpha in female liver as compared to male liver. Moreover, 90% of the genes showing sex-specific expression in the liver were shown to lose sex specificity in HNF4alpha-deficient liver. Keywords: genetic knockout and sex response
Project description:Understanding the molecular basis of sex differences in neural response to acute hypoxic insult has profound implications for the effective prevention and treatment of ischemic stroke. Global hypoxic-ischemic induced neural damage has been studied recently under the well-controlled, non-invasive, reproducible conditions using zebrafish model. Our earlier report on sex difference in global acute hypoxia induced neural damage and recovery in zebrafish prompted us for comprehensive study on the mechanisms underlying the recovery. An omics approach for studying quantitative changes in brain proteome upon hypoxia insult following recovery was undertaken using iTRAQ-based LC-MS/MS approach. The results shed light on altered expression of many regulatory proteins in zebrafish brain upon acute hypoxia following recovery. The sex difference in differentially expressed proteins along with the proteins expressed in uniform direction in both the sexes was studied. Core expression analysis by Ingenuity Pathway analysis (IPA) showed a distinct sex difference in the disease function heatmap. Most of the upstream regulators obtained through IPA were validated at the transcriptional level. Translational upregulation of H3K9me3 in male led us to elucidate the mechanism of recovery by confirming transcriptional targets through ChIP-qPCR. The upregulation of H3K9me3 level in male at 4 hr post-hypoxia appears to affect the early neurogenic markers nestin, klf4 and sox2, which might explain the late recovery in male, compared to female. Acute hypoxia-induced sex-specific comparison of brain proteome led us to reveal many differentially expressed proteins, which can be further studied for the development of novel targets for better therapeutic strategy.
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