Role of ß-3 adrenergic receptor polymorphism in overactive bladder.

AIMS: Women with overactive bladder (OAB) have a higher frequency of a single-nucleotide polymorphism (SNP) at codon 64 of the ß-3 adrenergic receptor gene (ADRB3). Since the SNP results in an amino acid substitution that could theoretically alter receptor protein function, we hypothesized that those with the SNP would display greater OAB symptom severity. Therefore we aimed to compare OAB severity between women with this SNP and women with the wild type genotype. METHODS: A retrospective cohort study was performed in women with bothersome OAB from two academic institutions. Banked blood samples were tested for the codon 64 SNP. Women were divided into two groups based on genotype: wild-type (WT) and heterozygous (HZ). We compared mean OAB Symptom Severity questionnaire (OAB-q) scores between groups using t tests. Linear regression was performed to control for potential confounders. RESULTS: Of the 303 women with OAB, 254 (83.8%) had the WT genotype, and 49 (16.2%) the HZ genotype. There were no homozygous women for the rare allele. The majority were Caucasian (86%) and non-Hispanic (97%). There were no significant differences in mean OAB-q symptom severity scores (WT 21.2 ± 7 vs HZ 22.0 ± 6.6; P = 0.49) and quality of life scores (WT 39.6 ± 15.5 vs HZ 39.1 ± 16.6; P = 0.83) between groups. These remained nonsignificant in a linear regression model. CONCLUSIONS: In a predominantly non-Hispanic, Caucasian population of women with bothersome OAB, symptom severity was not related to ADRB3 codon 64 SNP genotype.

Downregulation of SNCA Expression by Targeted Editing of DNA Methylation: A Potential Strategy for Precision Therapy in PD.

Elevated levels of SNCA have been implicated in the pathogenesis of Parkinson's disease (PD), while normal physiological levels of SNCA are needed to maintain neuronal function. We ought to develop new therapeutic strategies targeting the regulation of SNCA expression. DNA methylation at SNCA intron 1 regulates SNCA transcription, and PD brains showed differential methylation levels compared to controls. Thus, DNA methylation at SNCA intron 1 is an attractive target for fine-tuned downregulation of SNCA levels. Here we developed a system, comprising an all-in-one lentiviral vector, for targeted DNA methylation editing within intron 1. The system is based on CRISPR-deactivated Cas9 (dCas9) fused with the catalytic domain of DNA-methyltransferase 3A (DNMT3A). Applying the system to human induced pluripotent stem cell (hiPSC)-derived dopaminergic neurons from a PD patient with the SNCA triplication resulted in fine downregulation of SNCA mRNA and protein mediated by targeted DNA methylation at intron 1. Furthermore, the reduction in SNCA levels by the guide RNA (gRNA)-dCas9-DMNT3A system rescued disease-related cellular phenotype characteristics of the SNCA triplication hiPSC-derived dopaminergic neurons, e.g., mitochondrial ROS production and cellular viability. We established that DNA hypermethylation at SNCA intron 1 allows an effective and sufficient tight downregulation of SNCA expression levels, suggesting the potential of this target sequence combined with the CRISPR-dCas9 technology as a novel epigenetic-based therapeutic approach for PD.

A genome-scale DNA methylation study in women with interstitial cystitis/bladder pain syndrome.

AIMS: To assess the feasibility of using voided urine samples to perform a DNA methylation study in females with interstitial cystitis/bladder pain syndrome (IC/BPS) as compared to age- and race-matched controls. A unique methylation profile could lead to a non-invasive, reproducible, and objective biomarker that would aid clinicians in the diagnosis of IC/BPS. METHODS: Nineteen IC/BPS patients and 17 controls were included. IC/BPS patients had an Interstitial Cystitis Symptom Index score of >8; controls had no bladder symptoms. DNA was extracted from pelleted urine sediment. Samples with >500 ng of genomic DNA underwent quantitative DNA methylation assessment using the Illumina Infinium MethylationEPIC BeadChip. Age- and race-matching was applied prior to analysis. Linear regression models were used to compare average methylation between IC/BPS cases and controls at each cytosine guanine dinucleotide site (loci where methylation can occur). RESULTS: Sixteen participants (eight IC/BPS age- and race-matched to eight controls) had adequate DNA for methylation analysis. The median age was 43.5 years (interquartile range 33.8, 65.0), the median BMI was 27.1 (IQR 22.7, 31.4), and 14 were Caucasian (87.5%). A total of 688 417 CpG sites were analyzed. In exploratory pathway analysis utilizing the top 1000 differentially methylated CpG sites, the mitogen-activated protein kinase (MAPK) pathway was overrepresented by member genes. CONCLUSIONS: The results demonstrate the feasibility of using voided urine specimens from women with IC/BPS to perform DNA methylation assessments. Additionally, the data suggest genes within or downstream of the MAPK pathway exhibit altered methylation in IC/BPS.

Maternal adverse childhood experiences (ACEs) and offspring imprinted gene DMR methylation at birth.

Adverse childhood experiences (ACEs) contribute to numerous negative health outcomes across the life course and across generations. Here, we extend prior work by examining the association of maternal ACEs, and their interaction with financial stress and discrimination, with methylation status within eight differentially methylated regions (DMRs) in imprinted domains in newborns. ACEs, financial stress during pregnancy, and experience of discrimination were self-reported among 232 pregnant women. DNA methylation was assessed at PEG10/SGCE, NNAT, IGF2, H19, PLAGL1, PEG3, MEG3-IG, and DLK1/MEG3 regulatory sequences using pyrosequencing. Using multivariable linear regression models, we found evidence to suggest that financial stress was associated with hypermethylation of MEG3-IG in non-Hispanic White newborns; discrimination was associated with hypermethylation of IGF2 and NNAT in Hispanic newborns, and with hypomethylation of PEG3 in non-Hispanic Black newborns. We also found evidence that maternal ACEs interacted with discrimination to predict offspring PLAGL1 altered DMR methylation, in addition to interactions between maternal ACEs score and discrimination predicting H19 and SGCE/PEG10 altered methylation in non-Hispanic White newborns. However, these interactions were not statistically significant after multiple testing corrections. Findings from this study suggest that maternal ACEs, discrimination, and financial stress are associated with newborn aberrant methylation in imprinted gene regions.

Maternal tobacco smoke exposure is associated with increased DNA methylation at human metastable epialleles in infant cord blood.

Metastable epialleles (MEs) are genomic regions that are stochastically methylated prior to germ layer specification and exhibit high interindividual but low intra-individual variability across tissues. ME methylation is vulnerable to environmental stressors, including diet. Tobacco smoke (TS) exposure during pregnancy is associated with adverse impacts on fetal health and maternal micronutrient levels as well as altered methylation. Our objective was to determine if maternal smoke exposure impacts methylation at MEs. Consistent with prior studies, we observed reductions in one-carbon pathway micronutrients with gestational TS exposure, including maternal folate (P = 0.02) and vitamins B6 (P = 0.05) and B12 (P = 0.007). We examined putative MEs BOLA3, PAX8, and ZFYVE28 in cord blood specimens from 85 Newborn Epigenetics STudy participants. Gestational TS exposure was associated with elevated DNA methylation at PAX8 (+5.22% average methylation; 95% CI: 0.33% to 10.10%; P = 0.037). In human conceptal kidney tissues, higher PAX8 transcription was associated with lower methylation (R s = 0.55; P = 0.07), suggesting that the methylation levels established at MEs, and their environmentally induced perturbation, may have meaningful, tissue-specific functional consequences. This may be particularly important because PAX8 is implicated in several cancers, including pediatric kidney cancer. Our data are the first to indicate vulnerability of human ME methylation establishment to TS exposure, with a general trend of increasing levels of methylation at these loci. Further investigation is needed to determine how TS exposure-mediated changes in DNA methylation at MEs, and consequent expression levels, might affect smoking-related disease risk.

Sex-specific DNA methylation and associations with in utero tobacco smoke exposure at nuclear-encoded mitochondrial genes.

Sex-linked differences in mitochondrial ATP production, enzyme activities, and reactive oxygen species generation have been reported in multiple tissue and cell types. While the effects of reproductive hormones underlie many of these differences, regulation of sexually dimorphic mitochondrial function has not been fully characterized. We hypothesized that sex-specific DNA methylation contributes to sex-specific expression of nuclear genes that influence mitochondrial function. Herein, we analysed DNA methylation data specifically focused on nuclear-encoded mitochondrial genes in 191 males and 190 females. We found 596 differentially methylated sites (DMSs) (FDR p < 0.05), corresponding to 324 genes, with at least a 1% difference in methylation between sexes. To investigate the potential functional significance, we utilized gene expression microarray data. Of the 324 genes containing DMSs, 17 showed differences in gene expression by sex. Particularly striking was that ATP5G2, encoding subunit C of ATP synthase, contains seven DMSs and exhibits a sex difference in expression (p = 0.04). Finally, we also found that alterations in DNA methylation associated with in utero tobacco smoke exposure were sex-specific in these nuclear-encoded mitochondrial genes. Interestingly, the level of sex differences in DNA methylation at nuclear-encoded mitochondrial genes and the level of methylation changes associated with smoke exposure were less prominent than that of other genes. This suggests more conservative regulation of DNA methylation at these nuclear-encoded mitochondrial genes as compared to others. Overall, our findings suggest that sex-specific DNA methylation may help establish sex differences in expression and function and that sex-specific alterations in DNA methylation in response to exposures could contribute to sex-variable toxicological responses.

Sperm DNA methylation alterations from cannabis extract exposure are evident in offspring.

BACKGROUND: Cannabis legalization is expanding and men are the predominant users. We have limited knowledge about how cannabis impacts sperm and whether the effects are heritable. RESULTS: Whole genome bisulfite sequencing (WGBS) data were generated for sperm of rats exposed to: (1) cannabis extract (CE) for 28 days, then 56 days of vehicle only (~ one spermatogenic cycle); (2) vehicle for 56 days, then 28 days of CE; or (3) vehicle only. Males were then mated with drug-naïve females to produce F1 offspring from which heart, brain, and sperm tissues underwent analyses. There were 3321 nominally significant differentially methylated CpGs in F0 sperm identified via WGBS with select methylation changes validated via bisulfite pyrosequencing. Significant methylation changes validated in F0 sperm of the exposed males at the gene 2-Phosphoxylose Phosphatase 1 (Pxylp1) were also detectable in their F1 sperm but not in controls. Changes validated in exposed F0 sperm at Metastasis Suppressor 1-Like Protein (Mtss1l) were also present in F1 hippocampal and nucleus accumbens (NAc) of the exposed group compared to controls. For Mtss1l, a significant sex-specific relationship between DNA methylation and gene expression was demonstrated in the F1 NAc. Phenotypically, rats born to CSE-exposed fathers exhibited significant cardiomegaly relative to those born to control fathers. CONCLUSIONS: This is the first characterization of the effect of cannabis exposure on the entirety of the rat sperm methylome. We identified CE-associated methylation changes across the sperm methylome, some of which persisted despite a "washout" period. Select methylation changes validated via bisulfite pyrosequencing, and genes associated with methylation changes were involved in early developmental processes. Preconception CE exposure is associated with detectable changes in offspring DNA methylation that are functionally related to changes in gene expression and cardiomegaly. These results support that paternal preconception exposure to cannabis can influence offspring outcomes.

Epigenetic Regulation of Claudin-1 in the Development of Ovarian Cancer Recurrence and Drug Resistance.

Over 21,000 women are diagnosed with ovarian cancer (OC) in the United States each year and over half that number succumb to this disease annually, often due to recurrent disease. A deeper understanding of the molecular events associated with recurrent disease is needed to identify potential targets. Using genome-scale DNA methylation and gene expression data for 16 matched primary-recurrent advanced stage serous epithelial OCs, we discovered that Claudin-1 (CLDN1), a tight junction protein, shows a stronger correlation between expression and methylation in recurrent versus primary OC at multiple CpG sites (R= -0.47 to -0.64 versus R= -0.32 to -0.57, respectively). An independent dataset showed that this correlation is stronger in tumors from short-term (<3y) survivors than in tumors from long-term (>7y) survivors (R= -0.41 to -0.46 versus R= 0.06 to -0.19, respectively). The presence of this inverse correlation in short-term survivors and recurrent tumors suggests an important role for this relationship and potential predictive value for disease prognosis. CLDN1 expression increased following pharmacologic inhibition of DNA methyltransferase activity (p< 0.001), thus validating the role of methylation in CLDN1 gene inhibition. CLDN1 knockdown enhanced chemosensitivity and suppressed cell proliferation, migration, and wound healing (p< 0.05). Stable CLDN1 knockdown in vivo resulted in reduced xenograft tumor growth but did not reach significance. Our results indicate that the relationship between CLDN1 methylation and expression plays an important role in OC aggressiveness and recurrence.

DNA Methylation in Babies Born to Nonsmoking Mothers Exposed to Secondhand Smoke during Pregnancy: An Epigenome-Wide Association Study.

BACKGROUND: Maternal smoking during pregnancy is related to altered DNA methylation in infant umbilical cord blood. The extent to which low levels of smoke exposure among nonsmoking pregnant women relates to offspring DNA methylation is unknown. OBJECTIVE: This study sought to evaluate relationships between maternal prenatal plasma cotinine levels and DNA methylation in umbilical cord blood in newborns using the Infinium HumanMethylation 450K BeadChip. METHODS: Participants from the Newborn Epigenetics Study cohort who reported not smoking during pregnancy had verified low levels of cotinine from maternal prenatal plasma (0 ng/mL to <4 ng/mL), and offspring epigenetic data from umbilical cord blood were included in this study (n=79). Multivariable linear regression models were fit to the data, controlling for cell proportions, age, race, education, and parity. Estimates represent changes in response to any 1-ng/mL unit increase in exposure. RESULTS: Multivariable linear regression models yielded 29,049 CpGs that were differentially methylated in relation to increases in cotinine at a 5% false discovery rate. Top CpGs were within or near genes involved in neuronal functioning (PRKG1, DLGAP2, BSG), carcinogenesis (FHIT, HSPC157) and inflammation (AGER). Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggest cotinine was related to methylation of gene pathways controlling neuronal signaling, metabolic regulation, cell signaling and regulation, and cancer. Further, enhancers associated with transcription start sites were enriched in altered CpGs. Using an independent sample from the same study population (n=115), bisulfite pyrosequencing was performed with infant cord blood DNA for two genes within our top 20 hits (AGER and PRKG1). Results from pyrosequencing replicated epigenome results for PRKG1 (cg17079497, estimate=-1.09, standard error (SE)=0.45, p=0.018) but not for AGER (cg09199225; estimate=-0.16, SE=0.21, p=0.44). DISCUSSION: Secondhand smoke exposure among nonsmoking women may alter DNA methylation in regions involved in development, carcinogenesis, and neuronal functioning. These novel findings suggest that even low levels of smoke exposure during pregnancy may be sufficient to alter DNA methylation in distinct sites of mixed umbilical cord blood leukocytes in pathways that are known to be altered in cord blood from pregnant active smokers. https://doi.org/10.1289/EHP8099.

Male obesity impacts DNA methylation reprogramming in sperm.

BACKGROUND: Male obesity has profound effects on morbidity and mortality, but relatively little is known about the impact of obesity on gametes and the potential for adverse effects of male obesity to be passed to the next generation. DNA methylation contributes to gene regulation and is erased and re-established during gametogenesis. Throughout post-pubertal spermatogenesis, there are continual needs to both maintain established methylation and complete DNA methylation programming, even during epididymal maturation. This dynamic epigenetic landscape may confer increased vulnerability to environmental influences, including the obesogenic environment, that could disrupt reprogramming fidelity. Here we conducted an exploratory analysis that showed that overweight/obesity (n = 20) is associated with differences in mature spermatozoa DNA methylation profiles relative to controls with normal BMI (n = 47). RESULTS: We identified 3264 CpG sites in human sperm that are significantly associated with BMI (p < 0.05) using Infinium HumanMethylation450 BeadChips. These CpG sites were significantly overrepresented among genes involved in transcriptional regulation and misregulation in cancer, nervous system development, and stem cell pluripotency. Analysis of individual sperm using bisulfite sequencing of cloned alleles revealed that the methylation differences are present in a subset of sperm rather than being randomly distributed across all sperm. CONCLUSIONS: Male obesity is associated with altered sperm DNA methylation profiles that appear to affect reprogramming fidelity in a subset of sperm, suggestive of an influence on the spermatogonia. Further work is required to determine the potential heritability of these DNA methylation alterations. If heritable, these changes have the potential to impede normal development.

Epigenetic alterations in cytochrome P450 oxidoreductase (Por) in sperm of rats exposed to tetrahydrocannabinol (THC).

As marijuana legalization is increasing, research regarding possible long-term risks for users and their offspring is needed. Little data exists on effects of paternal tetrahydrocannabinol (THC) exposure prior to reproduction. This study determined if chronic THC exposure alters sperm DNA methylation (DNAm) and if such effects are intergenerationally transmitted. Adult male rats underwent oral gavage with THC or vehicle control. Differentially methylated (DM) loci in motile sperm were identified using reduced representation bisulfite sequencing (RRBS). Another cohort was injected with vehicle or THC, and sperm DNAm was analyzed. Finally, THC-exposed and control adult male rats were mated with THC-naïve females. DNAm levels of target genes in brain tissues of the offspring were determined by pyrosequencing. RRBS identified 2,940 DM CpGs mapping to 627 genes. Significant hypermethylation was confirmed (p < 0.05) following oral THC administration for cytochrome P450 oxidoreductase (Por), involved in toxin processing and disorders of sexual development. Por hypermethylation was not observed after THC injection or in the subsequent generation. These results support that THC alters DNAm in sperm and that route of exposure can have differential effects. Although we did not observe evidence of intergenerational transmission of the DNAm change, larger studies are required to definitively exclude this possibility.

Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models.

The use of hiPSC-derived cells represents a valuable approach to study human neurodegenerative diseases. Here, we describe an optimized protocol for the differentiation of hiPSCs derived from a patient with the triplication of the alpha-synuclein gene (SNCA) locus into Parkinson's disease (PD)-relevant dopaminergic neuronal populations. Accumulating evidence has shown that high levels of SNCA are causative for the development of PD. Recognizing the unmet need to establish novel therapeutic approaches for PD, especially those targeting the regulation of SNCA expression, we recently developed a CRISPR/dCas9-DNA-methylation-based system to epigenetically modulate SNCA transcription by enriching methylation levels at the SNCA intron 1 regulatory region. To deliver the system, consisting of a dead (deactivated) version of Cas9 (dCas9) fused with the catalytic domain of the DNA methyltransferase enzyme 3A (DNMT3A), a lentiviral vector is used. This system is applied to cells with the triplication of the SNCA locus and reduces the SNCA-mRNA and protein levels by about 30% through the targeted DNA methylation of SNCA intron 1. The fine-tuned downregulation of the SNCA levels rescues disease-related cellular phenotypes. In the current protocol, we aim to describe a step-by-step procedure for differentiating hiPSCs into neural progenitor cells (NPCs) and the establishment and validation of pyrosequencing assays for the evaluation of the methylation profile in the SNCA intron 1. To outline in more detail the lentivirus-CRISPR/dCas9 system used in these experiments, this protocol describes how to produce, purify, and concentrate lentiviral vectors and to highlight their suitability for epigenome- and genome-editing applications using hiPSCs and NPCs. The protocol is easily adaptable and can be used to produce high titer lentiviruses for in vitro and in vivo applications.

Urine RNA Processing in a Clinical Setting: Comparison of 3 Protocols.

OBJECTIVE: The objective of this study was to compare quantitative and qualitative RNA extraction results from clinical voided urine samples between 3 commercially available extraction protocols. METHODS: For phase 1, fresh voided urine samples from 10 female subjects were collected and processed in clinic and transported to the laboratory with cold packs. RNA was purified with 1 of 3 RNA extraction protocols: (1) TRI Reagent Protocol; (2) Absolutely RNA Nanoprep Kit; and (3) ZR Urine RNA Isolation Kit. Real-time polymerase chain reactions (RT-PCR) were performed. As the ZR Urine RNA Isolation Kit provided the highest quality RNA in phase 1, for phase 2, RNA was extracted from 9 additional voided urine specimens using this kit to perform additional qualitative analyses. RESULTS: Median RNA yield was significantly higher with the TRI Reagent Protocol as compared with the other protocols (P = 0.007). However, there was a significantly lower median threshold cycle value from polymerase chain reaction (indicating improved downstream application performance) with the ZR Urine RNA Isolation Kit as compared with the other methods (P = 0.005). In phase 2, the median RNA integrity number of urine RNA was 2.5 (range, 1.6-5.9). CONCLUSIONS: Although other methods may provide a higher quantity of RNA, when using clinical urine samples, the ZR Urine RNA Isolation Kit provided the highest quality of extracted RNA. This kit is especially attractive for the clinical setting because it does not require an initial centrifugation step. The urine RNA obtained with this kit may be useful for polymerase chain reaction but is not likely to be of high enough integrity for RNA sequencing.

MTAP Loss Promotes Stemness in Glioblastoma and Confers Unique Susceptibility to Purine Starvation.

Homozygous deletion of methylthioadenosine phosphorylase (MTAP) is one of the most frequent genetic alterations in glioblastoma (GBM), but its pathologic consequences remain unclear. In this study, we report that loss of MTAP results in profound epigenetic reprogramming characterized by hypomethylation of PROM1/CD133-associated stem cell regulatory pathways. MTAP deficiency promotes glioma stem-like cell (GSC) formation with increased expression of PROM1/CD133 and enhanced tumorigenicity of GBM cells and is associated with poor prognosis in patients with GBM. As a combined consequence of purine production deficiency in MTAP-null GBM and the critical dependence of GSCs on purines, the enriched subset of CD133+ cells in MTAP-null GBM can be effectively depleted by inhibition of de novo purine synthesis. These findings suggest that MTAP loss promotes the pathogenesis of GBM by shaping the epigenetic landscape and stemness of GBM cells while simultaneously providing a unique opportunity for GBM therapeutics. SIGNIFICANCE: This study links the frequently mutated metabolic enzyme MTAP to dysregulated epigenetics and cancer cell stemness and establishes MTAP status as a factor for consideration in characterizing GBM and developing therapeutic strategies.

DNA methylation of imprinted genes in Mexican-American newborn children with prenatal phthalate exposure.

AIM: Imprinted genes exhibit expression in a parent-of-origin-dependent manner and are critical for child development. Recent limited evidence suggests that prenatal exposure to phthalates, ubiquitous endocrine disruptors, can affect their epigenetic dysregulation. MATERIALS & METHODS: We quantified DNA methylation of nine imprinted gene differentially methylated regions by pyrosequencing in 296 cord blood DNA samples in a Mexican-American cohort. Fetal exposure was estimated by phthalate metabolite concentrations in maternal urine samples during pregnancy. RESULTS: Several differentially methylated regions of imprinted genes were associated with high molecular weight phthalates. The most consistent, positive, and false discovery rate significant associations were observed for MEG3. CONCLUSION: Phthalate exposure in utero may affect methylation status of imprinted genes in newborn children.

Cannabinoid exposure and altered DNA methylation in rat and human sperm.

Little is known about the reproductive effects of paternal cannabis exposure. We evaluated associations between cannabis or tetrahydrocannabinol (THC) exposure and altered DNA methylation in sperm from humans and rats, respectively. DNA methylation, measured by reduced representation bisulfite sequencing, differed in the sperm of human users from non-users by at least 10% at 3,979 CpG sites. Pathway analyses indicated Hippo Signaling and Pathways in Cancer as enriched with altered genes (Bonferroni p < 0.02). These same two pathways were also enriched with genes having altered methylation in sperm from THC-exposed versus vehicle-exposed rats (p < 0.01). Data validity is supported by significant correlations between THC exposure levels in humans and methylation for 177 genes, and substantial overlap in THC target genes in rat sperm (this study) and genes previously reported as having altered methylation in the brain of rat offspring born to parents both exposed to THC during adolescence. In humans, cannabis use was also associated with significantly lower sperm concentration. Findings point to possible pre-conception paternal reproductive risks associated with cannabis use.

Histone H3.3K27M Represses p16 to Accelerate Gliomagenesis in a Murine Model of DIPG.

Diffuse intrinsic pontine glioma (DIPG) is a highly aggressive pediatric brainstem tumor genetically distinguished from adult GBM by the high prevalence of the K27M mutation in the histone H3 variant H3.3 (H3F3A). This mutation reprograms the H3K27me3 epigenetic landscape of DIPG by inhibiting the H3K27-specific histone methyltransferase EZH2. This globally reduces H3K27me2/3, critical repressive marks responsible for cell fate decisions, and also causes focal gain of H3K27me3 throughout the epigenome. To date, the tumor-driving effects of H3.3K27M remain largely unknown. Here, it is demonstrated that H3.3K27M cooperates with PDGF-B in vivo, enhancing gliomagenesis and reducing survival of p53 wild-type (WT) and knockout murine models of DIPG. H3.3K27M expression drives increased proliferation of tumor-derived murine neurospheres, suggesting that cell-cycle deregulation contributes to increased malignancy in mutant tumors. RNA sequencing on tumor tissue from H3.3K27M-expressing mice indicated global upregulation of PRC2 target genes, and a subset of newly repressed genes enriched in regulators of development and cell proliferation. Strikingly, H3.3K27M induced targeted repression of the p16/ink4a (CDKN2A) locus, a critical regulator of the G0-G1 to S-phase transition. Increased levels of H3K27me3 were observed at the p16 promoter; however, pharmacologic reduction of methylation at this promoter did not rescue p16 expression. Although DNA methylation is also present at this promoter, it is not K27M dependent. Intriguingly, inhibition of DNA methylation restores p16 levels and is cytotoxic against murine tumor cells. Importantly, these data reveal that H3.3K27M-mediated p16 repression is an important mechanism underlying the proliferation of H3.3K27M tumor cells, as in vivo cdkn2a knockout eliminates the survival difference between H3.3K27M and H3.3WT tumor-bearing mice.Implications: This study shows that H3.3K27M mutation and PDGF signaling act in concert to accelerate gliomagenesis in a genetic mouse model and identifies repression of p16 tumor suppressor as a target of H3.3K27M, highlighting the G1-S cell-cycle transition as a promising therapeutic avenue. Mol Cancer Res; 15(9); 1243-54. ©2017 AACR.

Blood monocyte transcriptome and epigenome analyses reveal loci associated with human atherosclerosis.

Little is known regarding the epigenetic basis of atherosclerosis. Here we present the CD14+ blood monocyte transcriptome and epigenome signatures associated with human atherosclerosis. The transcriptome signature includes transcription coactivator, ARID5B, which is known to form a chromatin derepressor complex with a histone H3K9Me2-specific demethylase and promote adipogenesis and smooth muscle development. ARID5B CpG (cg25953130) methylation is inversely associated with both ARID5B expression and atherosclerosis, consistent with this CpG residing in an ARID5B enhancer region, based on chromatin capture and histone marks data. Mediation analysis supports assumptions that ARID5B expression mediates effects of cg25953130 methylation and several cardiovascular disease risk factors on atherosclerotic burden. In lipopolysaccharide-stimulated human THP1 monocytes, ARID5B knockdown reduced expression of genes involved in atherosclerosis-related inflammatory and lipid metabolism pathways, and inhibited cell migration and phagocytosis. These data suggest that ARID5B expression, possibly regulated by an epigenetically controlled enhancer, promotes atherosclerosis by dysregulating immunometabolism towards a chronic inflammatory phenotype.The molecular mechanisms mediating the impact of environmental factors in atherosclerosis are unclear. Here, the authors examine CD14+ blood monocyte's transcriptome and epigenome signatures to find differential methylation and expression of ARID5B to be associated with human atherosclerosis.

Optimizing Urine Processing Protocols for Protein and Metabolite Detection.

BACKGROUND: In urine, factors such as timing of voids, and duration at room temperature (RT) may affect the quality of recovered protein and metabolite data. Additives may aid with detection, but can add more complexity in sample collection or analysis. We aimed to identify the optimal urine processing protocol for clinically-obtained urine samples that allows for the highest protein and metabolite yields with minimal degradation. METHODS: Healthy women provided multiple urine samples during the same day. Women collected their first morning (1st AM) void and another "random void". Random voids were aliquotted with: 1) no additive; 2) boric acid (BA); 3) protease inhibitor (PI); or 4) both BA + PI. Of these aliquots, some were immediately stored at 4°C, and some were left at RT for 4 hours. Proteins and individual metabolites were quantified, normalized to creatinine concentrations, and compared across processing conditions. Sample pools corresponding to each processing condition were analyzed using mass spectrometry to assess protein degradation. RESULTS: Ten Caucasian women between 35-65 years of age provided paired 1st morning and random voided urine samples. Normalized protein concentrations were slightly higher in 1st AM compared to random "spot" voids. The addition of BA did not significantly change proteins, while PI significantly improved normalized protein concentrations, regardless of whether samples were immediately cooled or left at RT for 4 hours. In pooled samples, there were minimal differences in protein degradation under the various conditions we tested. In metabolite analyses, there were significant differences in individual amino acids based on the timing of the void. CONCLUSIONS: For comparative translational research using urine, information about void timing should be collected and standardized. For urine samples processed in the same day, BA does not appear to be necessary while the addition of PI enhances protein yields, regardless of 4°C or RT storage temperature.