Normal cells require continuous exposure to growth factors, in order to cross a restriction point and commit to cell cycle progression. This can be replaced by two short, appropriately spaced pulses of growth factors, where the first pulse primes a process, which is completed by the second pulse, and enables restriction point crossing. Through integration of comprehensive proteomic and transcriptomic analyses of each pulse, we identified three processes that regulate restriction point crossing: (i) The first pulse induces essential metabolic enzymes and activates p53-dependent restraining processes. (ii) The second pulse eliminates, via the PI3K/AKT pathway, the suppressive action of p53, as well as (iii) sets an ERK-EGR1 threshold mechanism, which digitizes graded external signals into an all-or-none decision obligatory for S-phase entry. Together, our findings uncover novel gating mechanisms, which ensure that cells ignore fortuitous growth factors, and undergo proliferation only in response to consistent mitogenic signals.
Two phases of mitogenic signaling unveil roles for p53 and EGR1 in elimination of inconsistent growth signals.
Specimen part, Cell line
View SamplesChronic alcohol consumption can lead to alchohol-related brain damage (ARBD). Despite the well known acute effects of alcohol the mechanism responsible for chronic brain damage is largely unknown. Pathologically the major change is the loss of white matter while neuronal loss is mild and restricted to a few areas such as the prefrontal cortex. In order to improve our understanding of ARBD pathogenesis we used microarrays to explore the white matter transcriptome of alcoholics and controls.
Comorbidities, confounders, and the white matter transcriptome in chronic alcoholism.
Specimen part, Disease, Disease stage
View SamplesEmbryonic stem cells (ESCs) maintain high genomic plasticity, essential for their capacity to enter diverse differentiation pathways. Post-transcriptional modifications of chromatin histones play a pivotal role in maintaining this plasticity. We now report that one such modification, monoubiquitylation of histone H2B on lysine 120 (H2BK120ub1), catalyzed by the E3 ligase RNF20, increases during ESC differentiation and is required for efficient execution of this process. This increase is particularly important for the transcriptional induction of long genes during ESC differentiation. Furthermore, we identify USP44 as a deubiquitinase whose downregulation by differentiation signals contributes to the increase in H2BK120ub1. Our findings suggest that optimal ESC differentiation requires dynamic changes in H2B ubiquitylation patterns, which must occur in a timely and well-coordinated manner.
RNF20 and USP44 regulate stem cell differentiation by modulating H2B monoubiquitylation.
Cell line, Treatment
View SamplesScalp psoriasis shows a variable clinical spectrum and in many cases poses a great therapeutic challenge. However, it remains unknown whether the immune response of scalp psoriasis differs from understood pathomechanisms of psoriasis on other skin areas. We sought to determine the cellular and mollecular phenotype of scalp psoriasis by performing a comparative analysis of scalp vs skin using lesional and nonlesional samples from 20 Caucasian subjects with untreated moderate to severe psoriasis and significant scalp involvement, and 10 control subjects without psoriasis. Our results suggest that even in the scalp psoriasis is a disease of the inter-follicular skin. The immune mechanisms that mediate scalp psoriasis were found to be similar to those involved in skin psoriasis. However, the magnitude of dysregulation, number of differentially expressed genes, and enrichment of the psoriatic genomic fingerprinting were more prominent in skin lesions. Furthermore, the scalp transcriptome showed increased modulation of several gene-sets, particularly those induced by interferon-gamma, compared with skin psoriasis which was mainly associated with activation of TNF/L-17/IL-22-induced keratinocyte response genes. We also detected differences in expression of gene-sets involving negative regulation, epigenetic regulation, epidermal differentiation, and dendritic cell or Th1/Th17/Th22-related T-cell processes.
Molecular and Cellular Profiling of Scalp Psoriasis Reveals Differences and Similarities Compared to Skin Psoriasis.
Specimen part, Disease, Disease stage
View SamplesDamage-associated molecular pattern (DAMP) molecules S100A8 and S100A9 with well-known functions in inflammation, tumor growth and metastasis. It has been found to have promote tumor cell proliferation activity at low concentration . However, the mechanism underlying this remains unclear. In the current study, we performed genome expression profiling analysis using the Affymetrix genome wide microarray system to identify broad scale changes in gene expression associated with S100a8 or S100a9 recombinant protein stimulation in murine colon carcinoma cell line CT26.WT.
Inflammation-induced S100A8 activates Id3 and promotes colorectal tumorigenesis.
Cell line
View SamplesThe intestinal epithelium constitutes a crucial defense to the potentially life-threatening effects of gut microbiota. However, due to a complex underlying vasculature, hypoperfusion and resultant tissue ischemia pose a particular risk to function and integrity of the epithelium. The small ubiquitin-like modifier (SUMO) conjugation pathway critically regulates adaptive responses to metabolic stress and is of particular significance in the gut, as inducible knockout of the SUMO-conjugating enzyme Ubc9 results in rapid intestinal epithelial disintegration. Here we analyzed the pattern of individual SUMO isoforms in intestinal epithelium and investigated their roles in intestinal ischemia/reperfusion (I/R) damage. Immunostaining revealed that epithelial SUMO2/3 expression was almost exclusively limited to crypt epithelial nuclei in unchallenged mice. However, intestinal I/R or overexpression of Ubc9 caused a remarkable enhancement of epithelial SUMO2/3 staining along the crypt-villus axis. Unexpectedly, a similar pattern was found in SUMO1 knockout mice. Ubc9 transgenic mice, but also SUMO1 knockout mice were protected from I/R injury as evidenced by better preserved barrier function and blunted inflammatory responses. PCR array analysis of microdissected villus-tip epithelia revealed a specific epithelial contribution to reduced inflammatory responses in Ubc9 transgenic mice, as key chemotactic signaling molecules such as IL17A were significantly downregulated. Together, our data indicate a critical role particularly of the SUMO2/3 isoforms in modulating responses to I/R and provide the first evidence that SUMO1 deletion activates a compensatory process that protects from ischemic damage.
Ubc9 overexpression and SUMO1 deficiency blunt inflammation after intestinal ischemia/reperfusion.
Treatment
View SamplesCellular differentiation requires both activation of target cell programs and repression of non-target cell programs. Transcriptional repressors such as RE1-silencing transcription factor (REST) and Hairy/Enhancer of Split (Hes) repress neuronal genes in non-neuronal cells. However, it is unknown whether transcriptional repressors of non-neuronal genes in neuronal precursors are required to specify neuronal fate during development. The Myt1 family of zinc finger transcription factors contributes to fibroblast to neuron reprogramming in vitro by repressing Notch signaling. Here, we show that ztf-11 (Zinc-finger Transcription Factor-11), the sole Caenorhabditis elegans Myt1 homolog, is required for neurogenesis in multiple neuronal lineages, including an in vivo developmental epithelial-to-neuronal transdifferentiation event. ztf-11 is exclusively expressed in all neuronal precursors with remarkable specificity at single cell resolution. Loss of ztf-11 leads to upregulation of non-neuronal genes and reduced neurogenesis. Ectopic expression of ztf-11 in epidermal lineages is sufficient to produce additional neurons. Our genetic and genomic experiments show that ZTF-11 indeed functions as a transcriptional repressor to suppress the activation of non-neuronal genes in neurons; however, it does not function via repression of Notch signaling. Instead, ZTF-11 binds to the MuvBco-repressor complex, which we show is also required for neurogenesis. These results dovetail with ability of Myt1l (Myt1-like) to drive neuronal transdifferentiation in vitro in vertebrate systems. Together, we identified an evolutionarily conserved mechanism to specify neuronal cell fate by repressing non-neuronal genes. Overall design: 4 biological replicates each under 2 experemental conditions (ztf-11 KD and negative control) were used for total of 8 samples
A Myt1 family transcription factor defines neuronal fate by repressing non-neuronal genes.
Specimen part, Cell line, Treatment, Subject
View SamplesIn human breast cancers, a phenotypically distinct minority population of tumorigenic cancer (TG) cells (sometimes referred to as cancer stem cells) drives tumor growth when transplanted into immunodeficient mice. Our objective was to identify a mouse model of breast cancer stem cells that could have relevance to studying human breast cancer. To do so, we utilized breast tumors of the MMTVWnt-1 mice. MMTV-Wnt-1 breast tumors were harvested, dissociated into single cell suspensions, and FACS sorted on Thy1, CD24, and CD45. FACS sorted cells were then injected into recipient background FBV/NJ female mice. Thy1+CD24+ cancer cells, which constitute approximately 1-4% of tumor cells were highly enriched for cells capable of regenerating new tumors when compared to cells of the tumor that did not fit this profile (Not Thy1+CD24+). Resultant tumors were of the same phenotypic diversity as the original tumor and behaved in a similar manner when passaged. Microarray analysis comparing Thy1+CD24+ tumor cells to Not Thy1+CD24+ cells identified a list of differentially expressed genes. Orthologs of these differentially expressed genes predicted survival of human breast cancer patients from two different study groups. These studies suggest that there is a cancer stem cell compartment in the MMTV-Wnt-1 murine breast tumor and that there is a clinical utility of this model for the study of cancer stem cells.
Isolation and molecular characterization of cancer stem cells in MMTV-Wnt-1 murine breast tumors.
No sample metadata fields
View SamplesAtopic dermatitis (AD) is a common inflammatory skin disease with a T(H)2 and T22 immune polarity. Despite recent data showing a genetic predisposition to epidermal barrier defects in some patients, a fundamental debate still exists regarding the role of barrier abnormalities versus immune responses in initiating the disease. An extensive study of nonlesional AD (ANL) skin is necessary to explore whether there is an intrinsic predisposition to barrier abnormalities, background immune activation, or both in patients with AD. We sought to characterize ANL skin by determining whether epidermal differentiation and immune abnormalities that characterize lesional AD (AL) skin are also reflected in ANL skin. We performed genomic and histologic profiling of both ANL and AL skin lesions (n = 12 each) compared with normal human skin (n = 10). We found that ANL skin is clearly distinct from normal skin with respect to terminal differentiation and some immune abnormalities and that it has a cutaneous expansion of T cells. We also showed that ANL skin has a variable immune phenotype, which is largely determined by disease extent and severity. Whereas broad terminal differentiation abnormalities were largely similar between involved and uninvolved AD skin, perhaps accounting for the background skin phenotype, increased expression of immune-related genes was among the most obvious differences between AL and ANL skin, potentially reflecting the clinical disease phenotype. Our study implies that systemic immune activation might play a role in alteration of the normal epidermal phenotype, as suggested by the high correlation in expression of immune genes in ANL skin with the disease severity index.
Nonlesional atopic dermatitis skin is characterized by broad terminal differentiation defects and variable immune abnormalities.
Specimen part, Subject
View SamplesBreast cancers contain a minority population of cancer cells characterized by CD44 expression but low or undetectable levels of CD24 (CD44+CD24-/low) that have higher tumorigenic capacity than other subtypes of cancer cells. METHODS: We compared the gene-expression profile of CD44+CD24-/low tumorigenic breast-cancer cells with that of normal breast epithelium. Differentially expressed genes were used to generate a 186-gene invasiveness gene signature (IGS), which was evaluated for its association with overall survival and metastasis-free survival in patients with breast cancer or other types of cancer. RESULTS: There was a significant association between the IGS and both overall and metastasis-free survival (P<0.001, for both) in patients with breast cancer, which was independent of established clinical and pathological variables. When combined with the prognostic criteria of the National Institutes of Health, the IGS was used to stratify patients with high-risk early breast cancer into prognostic categories (good or poor); among patients with a good prognosis, the 10-year rate of metastasis-free survival was 81%, and among those with a poor prognosis, it was 57%. The IGS was also associated with the prognosis in medulloblastoma (P=0.004), lung cancer (P=0.03), and prostate cancer (P=0.01). The prognostic power of the IGS was increased when combined with the wound-response (WR) signature. CONCLUSIONS: The IGS is strongly associated with metastasis-free survival and overall survival for four different types of tumors. This genetic signature of tumorigenic breast-cancer cells was even more strongly associated with clinical outcomes when combined with the WR signature in breast cancer.
The prognostic role of a gene signature from tumorigenic breast-cancer cells.
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