Literature context: Signaling Technology Cat# 9751; RRID:AB_2616028 Rabbit monoclonal anti-Histone3
The development of cell therapy for repairing damaged or diseased skeletal muscle has been hindered by the inability to significantly expand immature, transplantable myogenic stem cells (MuSCs) in culture. To overcome this limitation, a deeper understanding of the mechanisms regulating the transition between activated, proliferating MuSCs and differentiation-primed, poorly engrafting progenitors is needed. Here, we show that methyltransferase Setd7 facilitates such transition by regulating the nuclear accumulation of β-catenin in proliferating MuSCs. Genetic or pharmacological inhibition of Setd7 promotes in vitro expansion of MuSCs and increases the yield of primary myogenic cell cultures. Upon transplantation, both mouse and human MuSCs expanded with a Setd7 small-molecule inhibitor are better able to repopulate the satellite cell niche, and treated mouse MuSCs show enhanced therapeutic potential in preclinical models of muscular dystrophy. Thus, Setd7 inhibition may help bypass a key obstacle in the translation of cell therapy for muscle disease.
Literature context: gy Cat#9751S; RRID:AB_2616028 H2A Cell Signaling Technology C
Oncogene-induced senescence, e.g., in melanocytic nevi, terminates the expansion of pre-malignant cells via transcriptional silencing of proliferation-related genes due to decoration of their promoters with repressive trimethylated histone H3 lysine 9 (H3K9) marks. We show here that structurally distinct H3K9-active demethylases-the lysine-specific demethylase-1 (LSD1) and several Jumonji C domain-containing moieties (such as JMJD2C)-disable senescence and permit Ras/Braf-evoked transformation. In mouse and zebrafish models, enforced LSD1 or JMJD2C expression promoted Braf-V600E-driven melanomagenesis. A large subset of established melanoma cell lines and primary human melanoma samples presented with a collective upregulation of related and unrelated H3K9 demethylase activities, whose targeted inhibition restored senescence, even in Braf inhibitor-resistant melanomas, evoked secondary immune effects and controlled tumor growth in vivo.
Literature context: ing Technology Cat#: C42D8; RRID:AB_2616028 Chemicals, Peptides, and Recomb
To test the directness of factors in initiating PIWI-directed gene silencing, we employed a Piwi-interacting RNA (piRNA)-targeted reporter assay in Drosophila ovary somatic sheet (OSS) cells . This assay confirmed direct silencing roles for piRNA biogenesis factors and PIWI-associated factors [2-12] but suggested that chromatin-modifying proteins may act downstream of the initial silencing event. Our data also revealed that RNA-polymerase-II-associated proteins like PAF1 and RTF1 antagonize PIWI-directed silencing. PAF1 knockdown enhances PIWI silencing of reporters when piRNAs target the transcript region proximal to the promoter. Loss of PAF1 suppresses endogenous transposable element (TE) transcript maturation, whereas a subset of gene transcripts and long-non-coding RNAs adjacent to TE insertions are affected by PAF1 knockdown in a similar fashion to piRNA-targeted reporters. Additionally, transcription activation at specific TEs and TE-adjacent loci during PIWI knockdown is suppressed when PIWI and PAF1 levels are both reduced. Our study suggests a mechanistic conservation between fission yeast PAF1 repressing AGO1/small interfering RNA (siRNA)-directed silencing [13, 14] and Drosophila PAF1 opposing PIWI/piRNA-directed silencing.
Literature context: t#9751BF; RRID:AB_2616028 Rabbit ant
Type 2 diabetes (T2D) affects Latinos at twice the rate seen in populations of European descent. We recently identified a risk haplotype spanning SLC16A11 that explains ∼20% of the increased T2D prevalence in Mexico. Here, through genetic fine-mapping, we define a set of tightly linked variants likely to contain the causal allele(s). We show that variants on the T2D-associated haplotype have two distinct effects: (1) decreasing SLC16A11 expression in liver and (2) disrupting a key interaction with basigin, thereby reducing cell-surface localization. Both independent mechanisms reduce SLC16A11 function and suggest SLC16A11 is the causal gene at this locus. To gain insight into how SLC16A11 disruption impacts T2D risk, we demonstrate that SLC16A11 is a proton-coupled monocarboxylate transporter and that genetic perturbation of SLC16A11 induces changes in fatty acid and lipid metabolism that are associated with increased T2D risk. Our findings suggest that increasing SLC16A11 function could be therapeutically beneficial for T2D. VIDEO ABSTRACT.
Bisphenol A (BPA) is a ubiquitous endocrine disruptor exerting lifelong effects on gene expression in rodent prostate cancer (PCa) models. Here, we aimed to determine whether epigenetic events mediating the action of BPA on human prostaspheres enriched in epithelial stem-like/progenitor cells is linked to PCa. We performed genome-wide transcriptome and methylome analyses to identify changes in prostaspheres treated with BPA (10 nM, 200 nM, and 1000 nM) or estradiol-17β (E2) (0.1 nM) for 7 days and validated changes in expression, methylation, and histone marks in parallel-treated prostaspheres. BPA/E2-treatment altered expression of 91 genes but not the methylation status of 485,000 CpG sites in BPA/E2-treated prostaspheres. A panel of 26 genes was found repressed in all treatment groups. Fifteen of them were small nucleolar RNAs with C/D motif (SNORDs), which are noncoding, small nucleolar RNAs known to regulate ribosomal RNA assembly and function. Ten of the most down-regulated SNORDs were further studied. All 10 were confirmed repressed by BPA, but only 3 ratified as E2-repressed. SNORD suppression showed no correlation with methylation status changes in CpG sites in gene regulatory regions. Instead, BPA-induced gene silencing was found to associate with altered recruitments of H3K9me3, H3K4me3, and H3K27me3 to 5'-regulatory/exonic sequences of 5 SNORDs. Expression of 4 out of these 5 SNORDs (SNORD59A, SNORD82, SNORD116, and SNORD117) was shown to be reduced in PCa compared with adjacent normal tissue. This study reveals a novel and unique action of BPA in disrupting expression of PCa-associated SNORDs and a putative mechanism for reprogramming the prostasphere epigenome via histone modification.