Expression data from Wild type and Wip1 knockout Hematopoietic stem cell
ABSTRACT: Hematopoietic stem cell (HSC) aging underlies many age-related hematopoietic disorders. Accumulation of DNA damage is a hallmark of HSC aging. Wild-type p53-induced phosphatase 1 (Wip1) is a homeostatic regulator of DNA damage response. We used microarrays to detail the global programme of gene expression in Wip1 KO HSC Wild-type p53-induced phosphatase 1 (Wip1) knockout HSC and Wild type HSC were selected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Hematopoietic stem cell (HSC) aging underlies many age-related hematopoietic disorders. Accumulation of DNA damage is a hallmark of HSC aging. Wild-type p53-induced phosphatase 1 (Wip1) is a homeostatic regulator of DNA damage response. We used microarrays to detail the global programme of gene expression in Wip1 KO HSC Overall design: Wild-type p53-induced phosphatase 1 (Wip1) knockout HSC and Wild type HSC were selected for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Targeting the Mdm2 oncoprotein by drugs has the potential of re-establishing p53 function and tumor suppression. However, Mdm2-antagonizing drug candidates, e. g. Nutlin-3a, often fail to abolish cancer cell growth sustainably. To overcome these limitations, we inhibited Mdm2 and simultaneously a second negative regulator of p53, the phosphatase Wip1/PPM1D. When combining Nutlin-3a with the Wip1 inhibitor GSK2830371 in the treatment of p53-proficient but not p53-deficient cells, we observed enhanced phosphorylation (Ser 15) and acetylation (Lys 382) of p53, increased expression of p53 target gene products, and synergistic inhibition of cell proliferation. Surprisingly, when testing the two compounds individually, largely distinct sets of genes were induced, as revealed by deep sequencing analysis of RNA. In contrast, the combination of both drugs led to an expression signature that largely comprised that of Nutlin-3a alone. Moreover, the combination of drugs, or the combination of Nutlin-3a with Wip1-depletion by siRNA, activated p53-responsive genes to a greater extent than either of the compounds alone. Simultaneous inhibition of Mdm2 and Wip1 enhanced cell senescence and G2/M accumulation. Taken together, the inhibition of Wip1 might fortify p53-mediated tumor suppression by Mdm2 antagonists. Overall design: Expression profiling by high throughput sequencing
Project description:The number of newly-formed neurons declines rapidly during aging. Here we describe an important mechanism that contributes to this decline via Wip1-dependent regulation of neuronal differentiation. We found that Wip1 is expressed in neural stem/progenitor cells (NPCs) of the mouse subventricular zone and its upregulation at physiological levels maintained higher NPC numbers and neuronal differentiation in old mice. This resulted in markedly improved neuron formation and rescued a functional defect in fine odor discrimination in old mice. We identified Dkk3 as a key downstream target of Wip1 and found that its expression in SVZ is restricted to NPCs. Functionally, Dkk3 inhibited neuroblast formation by suppressing Wnt signaling, while deletion of Dkk3 or pharmacological reactivation of the Wnt pathway improved neuron formation and olfactory function in aged mice. We propose that Wip1 controls a Dkk3-dependent inhibition of neuronal differentiation during aging and thus regulating Wip1 levels could prevent certain aspects of functional decline of the aging brain. We found if neurospheres were derived from 18 months old mice, Wip1 transgenic neurospheres were more neurogenic than wt ones. This microarray was a pilot experiment to search the mechanism how Wip1 Transgene promoted neurogenesis, and found Dkk3 as a potential mediator. WT vs Wip1Tg neurospheres were cultured from mouse brain, and gene expression was compared using Illumina mouseWG-6 array
Project description:Assessment of p53 targets by gene expression array analysis in irradiated and nonirradiated Wip1+/+ and Wip1-/- MEFs. Keywords: response to gamma radiation Overall design: mRNA from each set of cells harvested four hours after IR (5 Gy) was used for gene expression microarray analysis of p53 target genes using the Affymetrix Mouse Genome 430 2.0 Chips.
Project description:Spermatogenesis plays an important role in the mammalian testis, involving in the complex processes of mitosis, meiosis, and spermiogenesis. Spermatogenesis may also be disrupted in the absence of the immunological and ‘fence’ functions of the BTB, resulting in male subfertility or infertility. Mice lacking wild-type p53-induced phosphatase 1 (Wip1) display male reproductive organ defects, but the molecular mechanisms underlying these abnormalities remain unclear. We explored the function of Wip1 in spermatogenesis and fertility by examining differences in the expressed testis proteome and phosphoproteome between Wip1-deficient and wild-type mice using a proteomics approach. Among a total of 6872 proteins and 4280 phosphorylation sites on 1614 proteins identified in our analysis, 58 proteins and 159 phosphorylation sites on 141 proteins were differentially regulated between these two groups of mice. These results suggested that proinflammatory cytokines may impair the blood–testis barrier dynamics by decreasing the expression of junction-associated proteins, which effect could be partially responsible for the subfertility and spermatogenesis defects in Wip1-knockout mice.
Project description:Assessment of p53 targets by gene expression array analysis in irradiated and nonirradiated Wip1+/+ and Wip1-/- MEFs. Experiment Overall Design: mRNA from each set of cells harvested four hours after IR (5 Gy) was Experiment Overall Design: used for gene expression microarray analysis of p53 target genes using the Affymetrix Mouse Genome 430 2.0 Chips.
Project description:WIP1 phosphatase is emerging as an important regulator of tumorigenesis, but no unifying mechanistic network has been proposed. Here we found that WIP1 plays a key role in the transcriptional regulation of heterochromatin-associated DNA sequences in germ-line and cancer cells. WIP1 was required for epigenetic remodeling of repetitive DNA elements within the heterochromatin, including L1 LINE retrotransposons. Mechanistically, WIP1regulated an ATM-dependent increase in BRCA1 occupancy on L1 LINEs, resulting in closed chromatin without ubiquitination of histone H2A. This mechanism appeared to be dependent on the ability of BRCA1 to bind the heterochromatin protein HP1, the recruitment of DNA methyltransferases, and subsequent DNA methylation. Attenuation of ATM, in turn, reversed heterochromatin methylation in both germ-line and cancer cells. DNA methylation plays a central role in the generation of mutations in human tumors and we found that WIP1 levels strongly correlated with C-to-T substitutions and a total mutation load in primary breast cancers. We propose that WIP1 plays an important role in the regulation of DNA methylation and global heterochromatin silencing, and thus is critical in maintaining genome integrity during development and in cancer. Total RNA was extracted from control spermatids, Wip1-/- and Wip1-/- Atm+/- spermatids. The final cRNA samples were hybridized in triplicates to Illumina Mouse WG-6 v2.0 Expression arrays.
Project description:Transcriptional profiling of mouse liver tissues comparing Wild type liver tissues with Wip1 KO mice liver tissues after Partial Hepatectomy at 24h and 36 h. WT vs. Wip1 KO tissues after Partial Hepatectomy at 24h and 36 h .
Project description:Quiescent hematopoietic stem cells (HSCs) are prone to mutagenesis, and accumulation of mutations can result in hematological malignancies. The mechanisms through which HSCs prevent such detrimental accumulation, however, are unclear. Here, we show that Aspp1 coordinates with p53 to maintain the genomic integrity of the HSC pool. Aspp1 is preferentially expressed in HSCs and restricts HSC pool size by attenuating self-renewal under steady state conditions. After genotoxic stress, Aspp1 promotes HSC cycling and induces p53-dependent apoptosis in cells with persistent DNA damage foci. Beyond these p53-dependent functions, Aspp1 attenuates HSC self-renewal and accumulation of DNA damage in p53-null HSCs. Consequently, concomitant loss of Aspp1 and p53 leads to the development of hematological malignancies, especially T-cell leukemia and lymphoma. Together, these data highlights coordination between Aspp1 and p53 in regulating HSC self-renewal and DNA damage tolerance, and suggest that HSCs possess specific mechanisms that prevent accumulation of mutations and malignant transformation. 8-week-old WT, Aspp1-/-, Mx1-Cre(+)p53flox/flox and Mx1-Cre(+)Aspp1-/-p53flox/flox mice were intraperitoneally administered with 400 μg pIpC five times every other day to obtain WT, Aspp1-/-, p53-/- and Aspp1-/-p53-/- bone marrow. 4 weeks after pIpC treatment, bone marrow lineage(-) Sca-1(+) cKit(+) cells were isolated. RNA was extracted and pooled from 3 independent mice per genotype. RNA samples were then amplified, labeled, and hybridized to independent arrays.
Project description:The wild-type p53-induced phosphatase 1 (WIP1) frustrated mice exhibited defects in reproductive organs. This study aimed to understand how Wip1 deficiency affects the spermatogenesis or maturation. We employed the Wip1-/- mouse model and conducted a gel-free iTRAQ LC-MS/MS based quantitative proteomics analysis of whole epididymis including the sperms and somatic tissue. A total of 8763 proteins were identified, of which 91 were significantly differentially expressed proteins (DEPs) in the Wip1 depleted mice. Four DEPs (PRM2, ODF1, PIWIL1 and KLHL10) were confirmed with western blotting. The DEPs enriched in biological process of reproduction were identified by GO analysis and further confirmed in the mouse phenotype database. Pathway analysis suggested that Smac/Diablo-mediated apoptosis pathway and SERPINA3-mediated inflammatory process might contribute to the atrophy and the marked sperm decrease in epididymis. Network analysis of productivity related DEPs revealed possible interactions that WIP1 might affect the sperm maturation by decreasing the outer dense fiber protein 1 (ODF1) and protamine-2 (PRM2), and increasing the PIWIL1/MIWI through p53. PRM2 was down-regulated and PIWIL1 was up-regulated by immunohistochemistry staining. It was further confirmed that the spermatid deficiency began from the testis observed by HE staining. Therefore, WIP1 disruption caused the deficiency of spermatogenesis potentially through regulating the expression of the above DEPs and pathways.