Primary efficacy endpoint in both trials was treatment success, d

Primary efficacy endpoint in both trials was treatment success, defined as

both clinical and mycological response at end of therapy. In the micafungin/L-AmB trial, 183/489 patients had malignancy (37% neutropenic). In the micafungin/caspofungin trial, 176/572 patients had malignancy (26% neutropenic). Micafungin treatment success rates were generally similar in patients with/without malignancy and to rates observed with L-AmB and caspofungin. Most patients with malignancy and neutropenia were successfully treated by all three drugs. For all drugs, Ibrutinib chemical structure incidence of discontinuations because of treatment-related adverse events was similar for patients with malignancy (≤7.7%) vs. no malignancy (≤8.0%). These results suggest that compared with L-AmB and caspofungin, micafungin was effective and well tolerated in patients with candidiasis/candidaemia with/without malignancy. Further prospective trials are recommended to evaluate comparative NVP-AUY922 in vivo outcomes with a primary focus on patients with malignancies and invasive candidiasis. “
“The Trichophyton mentagrophytes complex is the main cause of superficial mycoses in humans and animals. Molecular research

has provided useful insights into the taxonomy of this complex to overcome the challenges with conventional diagnostics. The aim of this study was to identify, type and differentiate anthropophilic and zoophilic species of the T. mentagrophytes complex. Sixty clinical samples identified as T. mentagrophytes by morphological characteristics were isolated using polymerase chain reaction-restriction fragment length polymorphism

and sequence analysis of the internal transcribed spacer (ITS) regions. The identification of our strains by conventional methods was confirmed using polymerase chain reaction (PCR) sequencing in 93.34% of the cases. ifoxetine The strains under investigation were recategorised as T. rubrum (Tr2711). In addition, PCR products were independently digested with the restriction endonucleases, MvaI and HinfI, to produce a single dominant profile for T. interdigitale. ITS sequence analysis revealed a polymorphism in the ITS1 and 5.8S regions. Analysis of the consensus sequences distinguished four types of genotypes among our T. interdigitale species. Moreover, ITS type I was the dominant genotype characterising the anthropophilic variant of T. interdigitale. The phylogenetic study showed that only 5% of our strains were zoophilic. PCR sequencing was useful for distinguishing anthropophilic and zoophilic species of T. interdigitale, in which the differentiation is relevant because it helps to prescribe the correct treatment and to identify the surrounding source of infection. “
“To determine the epidemiology, risk factors for and outcome of candidaemia in critically ill patients, a matched case–control study was performed in a 25-bed intensive care unit (ICU) from August 2004 to January 2006.

Clostridium septicum is a gram-positive, spore-forming anaerobe t

Clostridium septicum is a gram-positive, spore-forming anaerobe that causes

a variety of disease syndromes in humans and animals [1, 2]. This organism produces several extracellular factors, including deoxyribonuclease, hyaluronidase, neuraminidase and alpha-toxin [3]. Alpha-toxin, the major virulent factor, has hemolytic, lethal and necrotizing activities [4, 5]. Alpha-toxin is a pore-forming toxin that belongs to the same family as aerolysin from Aeromonas hydrophila [6] and epsilon-toxin from Clostridium perfringens [7]. Alpha-toxin is secreted by the organism as an inactivated 46 kDa protoxin [8, 9]. The protoxin binds to GPI-anchored proteins on cell surfaces with high affinity [10, 11]. The protoxin is then cleaved to its 43 kDa active form by host cell proteases, such as furin [5, 8]. Activated toxin Enzalutamide monomers interact with each other on DRMs to form oligomeric prepore complexes [12, 13]. The prepore complexes ultimately insert into the plasma membrane, generating pores that are approximately 1.3–1.6 nm in diameter [4, 8]. Alpha-toxin and aerolysin show structural and functional similarities, at the level of 72%, with 27% identity [6, 9]. Although GPI-anchored NVP-LDE225 cell line proteins also act as receptors for aerolysin, each toxin binds to different subsets of GPI-anchored proteins [10]. Furthermore, the most striking difference between

alpha-toxin and aerolysin is that D1 of aerolysin is missing from the amino terminus in alpha-toxin, implying that alpha-toxin is a single-lobed structure consisting of three domains, D1, D2, and D3, which are homologous to D2, D3, and D4 of aerolysin, respectively (Fig. 1) [6, 14, 15]. The functional domains and

amino acids of alpha-toxin involved in receptor binding, oligomerization and pore formation have been identified by Melton et al. [14, 16]. Binding of alpha-toxin to GPI-anchored proteins is restricted to D1 [16]. Because cholesterol is essential isometheptene to binding and stability on the cellular membrane for many kinds of pore-forming toxins from gram-positive bacteria, these toxins have been named CDCs. CDCs that bind specifically to membrane cholesterol, such as perfringolysin O [17], streptolysin O [18], pneumolysin [19] and listeriolysin O [20], have a region of 11 highly conserved amino acid residues, ECTGLAWEWWR (tryptophan-rich motif) that is located in the C-terminal region of each toxin. In perfringolysin O, three tryptophan residues in the tryptophan-rich motif have an important role in binding to the cell membrane [21]. Although C. septicum alpha-toxin does not bind to cholesterol but to GPI-anchored proteins on the cell surface, alpha-toxin also has a tryptophan-rich region lying within an 11 amino acid sequence in D1 near the C terminus (NGYSEWDWKWV; residues 302–312; Fig. 1) [6]. In a previous study, Melton-Witt et al.

albicans (Fig  5) The structural and bioimmunological analysis o

albicans (Fig. 5). The structural and bioimmunological analysis of Candida mannans has mostly been conducted using yeast cells form grown at 28 °C. Nevertheless, Candida cells become pathogenic and invade tissue in the hyphal form at 37 °C [30, 31]. Recently, it has been shown that presence of the α-1,6-linked branching

mannose residues in mannan structure is reduced in Candida hyphal form mannan [8]. IgM and IgG antibodies levels induced by both conjugates immunization were slightly higher for hyphal morphological form of C. albicans (Fig. 5). Difference in α-1,6-linked branching presence in mannan of C. albicans yeast and hyphal form and detected antibody levels indicate that recognized antigenic determinants are α-1,6-linked branching independent. Torin 1 mouse We can suppose that observed difference in induction of humoral immune response by M5-BSA and M6-BSA conjugates is less related to difference in oligomannoside length and is more related to structure diversity,

concretely branching difference at non-reducing end of oligomers. Generally, oligosaccharides of intermediate length are required for the carbohydrate components of conjugate vaccines to obtain conformation similar to GPCR Compound Library purchase its native state on the cell surface. In the case of β-1,2-linked mannooligomers, the size of the epitopes that are able to induce protective antibodies is 2 or 3 residues [1]. We can suppose that dominant antigenic determinants of α-1,6-branched oligomannosides are not related

to branching site. In addition, whole cell ELISA assay reveal marked non-specific interaction of serum antibodies with Candida whole cells of both morphological forms. Determination of the source of non-specific interactions requires further investigation. IgGl and IgG2a subclass antibodies play a significant role in the opsonization either in the presence or absence of complement [32]. A comparison of the levels of IgGl and IgG2a indicates poor correlation between the putative Th responses Fossariinae initiated and mice strain susceptibility to infection [33]. Experimental infection of BALB/c mice with low susceptibility to Candida infection produced increased levels of IgGl instead of IgG2a [33]. By immunization with semi-synthetic oligomannoside-BSA conjugates M5-BSA and M6-BSA, we observed in agreement with mentioned report increase in IgG1 levels instead of IgG2a. The ability of immune sera to enhance the candidacidal activity of PMN was studied according to previously published candidacidal assay [14]. The published observations of efficient yeast cells opsonophagocytosis revealed ability of mannan-specific antibodies alone to serve as sufficient opsonins [34]. These results are supported by an earlier report of C. albicans yeast cells opsonophagocytic killing by human neutrophils induced by natural anti-mannan antibodies [35].

Since CSF is in steady contact with the brain tissue, this settin

Since CSF is in steady contact with the brain tissue, this setting represents the best possible in vitro model for the conditions in the CNS. Elimination of complement proteins was used as a relevant parameter to quantify the action of the fungal proteases and to investigate elimination of complement as

effective evasion strategy. A putative correlation between the phylogenetic background and the degradation of complement proteins is of particular interest to find an explanation Kinase Inhibitor Library for the differences between the species concerning virulence and triggered clinical symptoms. For that reason several strains of P. boydii, P. apiosperma and S. dehoogii were studied for their ability to eliminate complement

proteins to acquire nutrients and to evade complement attack in the infected host. The isolates of P. apiosperma, P. boydii and S. dehoogii with their corresponding CBS number and their origin are listed in Table 1. The identity of all isolates was confirmed by ITS sequencing. For some experiments, a clinical isolate of Aspergillus fumigatus obtained from a hospitalised patient with cerebral aspergillosis was used; the patient suffered from acute myeloic leukaemia KPT 330 and neutropenia as underlying disease. Long-term storage of all conidia was executed at −80 °C in phosphate buffered saline (PBS) supplemented with 20% glycerol. Experiments with fungal growth in CSF were performed with freshly harvested conidia: fungi were grown for at least 5 days on Sabouraud (BD Diagnostic Systems, Franklin Lakes, NJ, USA) agar plates at 28 °C until sporulation was clearly visible; conidia were swept off from sporulating colonies with PBS containing 0.05% Tween-20 (Sigma, St. Louis, MO, USA) and kept at 4 °C. Pure cultures of the fungal isolates were

grown on oatmeal agar or malt extract agar. The extraction of DNA was performed as described previously.5 Briefly, mycelia were disrupted mechanically and the DNA was purified from the homogenate using chloroform and precipitation with ice-cold ethanol. After centrifugation, the pelleted DNA was resolved in TE buffer followed by treatment with RNase. The PCR for ITS-amplification was performed using the primer pair V9G and LS266, whereas the primers ITS4 and ITS5 were Farnesyltransferase used for sequencing.11 Alignments were done with the help of muscle software;24 maximum parsimony was calculated by means of mega 4.0.25 Deposition of complement proteins on the surface of fungal hyphae was analysed using either human serum or CSF as complement source. For that purpose, human serum was obtained from 5 to 6 healthy individuals, pooled and stored frozen at −80 °C for further use. Cerebrospinal fluid pools were obtained from 15 individuals who were investigated for neurological non-inflammatory diseases and also stored at −80 °C. The CSF samples with traces of bleeding or elevated albumin levels were excluded.

[53, 54] Infection of the central nervous system (CNS) by hRSV ha

[53, 54] Infection of the central nervous system (CNS) by hRSV has been supported by the presence of viral RNA in human cerebrospinal fluid,[53] which correlates with neurological symptoms including seizures, central apnoea, lethargy, feeding or swallowing difficulties, abnormalities of muscle tone, strabismus, abnormalities

of the cerebrospinal fluid and encephalopathy.[54] Our group evaluated whether the CNS of mice and rats challenged with hRSV can be reached by this virus after intranasal infection.[55] The presence of hRSV was corroborated in brain tissues using immunofluorescence and real-time PCR assays, which showed hRSV proteins and nucleic acids in several zones of the brain, supporting PF-02341066 research buy the notion that hRSV infection reaches the CNS.[55] Entrance of

hRSV to Ivacaftor chemical structure the CNS was dependent on the blood–brain barrier, because the blockade of CD49d by a monoclonal antibody that targets integrin α4 and impairs leucocyte extravasation through the blood–brain barrier decreased viral loads in the brain but not in the lungs.[55] As a result of hRSV infection, impairment in cognition was revealed in rodents submitted to water-maze as a spatial learning test and to marble burying as a behavioural test.[55] These alterations were correlated with electrophysiological studies that showed an impairment in the induction of long-term potentiation in stratum radiatum at the hippocampus area.[55] Together, these observations support the previously described notion that hRSV has the ability to infect CNS tissues in a disseminated pattern and that this virus is capable of disrupting cognitive functions by altering

the synaptic plasticity of the infected brain tissue.[55] Human RAS p21 protein activator 1 RSV is considered an important health burden affecting mainly children and the elderly. Unfortunately, currently available treatments for infections by this pathogen are limited and it is not possible to use them broadly because of their high cost. However, there are many efforts invested in the design of new drugs to control the symptoms and unwanted effects caused by hRSV infection. The knowledge of the life cycle of hRSV and the pathology induced in the infected host is essential for the design of drugs with curative or prophylactic purposes. Along these lines, the most relevant processes in the life cycle of hRSV are replication, transcription and fusion, which are potential targets for antiviral drugs.[56] Table 1 summarizes the antiviral drugs designed up to date against hRSV infection.

12–15 In addition to aiding in the early diagnosis and prediction

12–15 In addition to aiding in the early diagnosis and prediction, they should be highly specific for AKI, and enable the identification

of AKI subtypes and aetiologies. AKI is traditionally diagnosed when the kidney’s major function learn more (glomerular filtration) is affected, and indirectly measured by change in serum creatinine. However, pre-renal factors such as volume depletion, decreased effective circulating volume or alterations in the calibre of the glomerular afferent arterioles all cause elevations in serum creatinine. Post-renal factors such as urinary tract obstruction similarly result in elevations in serum creatinine. Finally, a multitude of intrinsic renal diseases may result in abrupt rise in serum creatinine, particularly in hospitalized patients. Other tests to distinguish these various forms of AKI such as microscopic urine examination for casts and determination of fractional excretion GDC-0068 cell line of sodium have

been imprecise and have not enabled efficient clinical trial design. Availability of accurate biomarkers that can distinguish pre-renal and post-renal conditions from true intrinsic AKI would represent a significant advance. Biomarkers may serve several other purposes in AKI.12–15 Thus, biomarkers are also needed for: (i) identifying the primary location of injury (proximal tubule, distal tubule, interstitium or vasculature); (ii) pinpointing the duration of kidney failure

(AKI, chronic kidney disease (CKD) or ‘acute-on-chronic’ kidney injury); (iii) identifying AKI aetiologies (ischaemia, toxins, sepsis or a combination); (iv) risk stratification and prognostication (duration and severity of AKI, need for dialysis, length of hospital stay, mortality); and (v) monitoring the response to AKI interventions. Furthermore, AKI biomarkers may play a critical role in expediting the drug development process. The Critical Path Initiative first issued by the Food and Drug Administration in 2004 stated that ‘Additional biomarkers (quantitative measures of biologic effects that provide informative links between mechanism of L-NAME HCl action and clinical effectiveness) and additional surrogate markers (quantitative measures that can predict effectiveness) are needed to guide product development’. Collectively, it is envisioned that biomarkers will play an indispensable role in personalizing nephrologic care, by providing a more precise determination of disease predisposition, diagnosis and prognosis, earlier preventive and therapeutic interventions, a more efficient drug development process, and a safer and more fiscally responsive approach to medicine.

Caspase-1

is present in the cytosol of phagocytic cells a

Caspase-1

is present in the cytosol of phagocytic cells as an inactive zymogen 4, 5. Upon stimulation of phagocytic cells by pro-inflammatory signals, the procaspase-1 zymogen is activated by self-cleavage at aspartic residues to generate the enzymatically active homodimer of catalytic domains, consisting of a p20 and a p10 subunit 6, 7. Although it has long been recognized that microbial stimuli elicit the secretion of mature IL-1β, the cellular machinery mediating the activation of caspase-1 was only identified in 2002 when Tschopp and colleagues described the inflammasome, a multi-protein complex that induces robust processing Ku-0059436 molecular weight of proIL-1β 8. Here we discuss recent findings about caspase-1 activation with an emphasis on the regulation of the NLRC4 and NLRP3 inflammasomes by microbial stimuli. The NLR family is composed of more than 20 family members in mammals which share a tripartite structure consisting of a variable N-terminal domain, a centrally located nucleotide-binding oligomerization domain (NOD) and a C-terminal leucine-rich repeat for upstream sensing. While NOD1 and NOD2 activate NF-κB and MAPK in response to peptidoglycan fragments, PD0332991 concentration a class of NLR including NLRC4, NLRP1

and NLRP3 function as caspase-1 activators 9. These NLR contain N-terminal CARDs or PYRIN domains that mediate the assembly of the inflammasome through NOD-mediated oligomerization and interaction with caspase-1 via the adaptor ASC 6. Human NLRP1 senses bacterial muramyl dipeptide whereas mouse Nlrp1b recognizes lethal toxin, which is secreted by Bacillus anthracis6. Recently, the HIN-200 family member AIM2 has been shown to be a crucial molecule linking cytosolic double strand DNA to caspase-1 activation 10. AIM2 regulates the host response to vaccinia OSBPL9 viruses, but further work is needed to understand the role of AIM2 in microbial recognition 10. We discuss in more detail in the following two sections the NLRC4 and NLRP3 inflammasomes. Several Gram-negative bacteria, including Salmonella

enterica serovar Typhimurium, Legionella pneumophila, Pseudomonas aeruginosa and Shigella flexneri induce caspase-1 activation via the NLRC4 inflammasome 11–18. Although NLRC4 contains a CARD that presumably associates directly with that present in pro-caspase-1 19, the adaptor ASC is still required for caspase-1 activation and IL-1β secretion in response to bacterial infection 12, 20. The role of ASC in the NLRC4 inflammasome is still unclear, but it may promote the recruitment and/or dimerization of caspase-1 directly or through unknown factors. Several Gram-negative bacteria that activate the NLRC4 inflammasome require a functional type III secretion system or type IV secretion system to induce caspase-1 activation 6. These bacterial secretion systems form pores in host membranes to inject virulence factors into the host cell cytosol 6.

Moreover, the feasibility of macrophage therapy has recently been

Moreover, the feasibility of macrophage therapy has recently been

demonstrated in two renal transplant recipients,[124] where regulatory macrophages (IFN-γ-stimulated) were administered via central venous infusion several days prior to donor transplantation. Both patients underwent a rapid reduction in immunosuppressive therapy and maintained stable graft function during the 3-year follow-up period. These findings have now prompted The One Study, a multinational clinical trial for the use of regulatory macrophages as a potential immune-conditioning therapy in renal transplantation (see http://www.onestudy.org). As this review highlights, more needs BYL719 concentration to be understood in terms of macrophage phenotype and function in humans, and the processes that control their activation during the various stages of acute and chronic disease progression. A greater understanding of these different states of activation may result in the development of therapies specifically designed to capitalize

on this variation in phenotype and cellular responses. Alectinib
“Oxidative stress plays an important role in the progression of renal interstitial fibrosis. The nicotinamide adeninedinucleotide phosphate (NADPH) oxidase (Nox) family is considered one of the major sources of reactive oxygen species (ROS). In the present study, we investigated the inhibitory effects of a novel anti-fibrotic

agent, Fluorofenidone (AKF-PD), upon Nox-mediated oxidative stress and deposition of extracellular matrix (ECM) in the development of renalinterstitial fibrosis. AKF-PD was used to treat renal fibrosis in unilateral ureteral obstruction (UUO) obstructive nephropathy in rats. The expression of Nox homologues, p-Akt, collagen I and III were detected by immunoblotting or immunohistochemistry. Levels of 8-iso prostaglandin F2alpha (8-Iso PGF2a) was measured by enzyme linked immunosorbent assay. In addition, ROS and the expression of collagen I (1a), Nox subunits and p-Akt was measured in angiotensin (Ang) II-stimulated Decitabine clinical trial rat proximal tubular epithelial (NRK-52E) cells in culture. AKF-PD treatment significantly attenuated tubulo-interstitial injury, ECM deposition and oxidative stress in fibrotic rat kidneys. In addition, AKF-PD inhibited the expression of ROS, Collagen I (1a), Nox2, p-Akt in Ang II-stimulated NRK-52E cells. AKF-PD attenuates the progression of renal interstitial fibrosis partly by suppressing NADPH oxidase and ECM deposition via the PI3K/Akt signalling pathway, suggesting AKF-PD is a potential novel therapeutic agent against renal fibrosis. “
“Renal transplant recipients are at risk of developing Pneumocystis pneumonia (PcP), especially in the first 2 years after transplantation, with a mortality rate of up to 50%.

The transcription factor interferon regulatory factor 5 (IRF5) is

The transcription factor interferon regulatory factor 5 (IRF5) is one SLE susceptibility gene recently identified [[6]]. Multiple studies have confirmed the presence of IRF5 genetic variants that show strong association with increased risk of developing SLE [[6-8]]. Association has been convincingly replicated in SLE patients from multiple populations and distinct IRF5 haplotypes that EPZ-6438 cell line confer either susceptibility to (risk), or protection from, SLE in persons of varying ethnic ancestry have been identified [[6-11]]. A potential biologic role for IRF5 in human SLE pathogenesis has been supported

by the fact that elevated IRF5 mRNA levels are associated with specific IRF5 risk variants [[7, 8, 12, 13]]. Subsequently, we demonstrated that IRF5 mRNA and protein abundance were significantly elevated in primary blood cells of SLE patients, as compared to healthy donors, independent of IRF5 risk variants;

however, a correlation between IRF5 expression and the IRF5 risk haplotype was obtained [[14]]. These data support a more global role for Ponatinib molecular weight IRF5 in SLE pathogenesis that is both genotype dependent and genotype independent. IRF5 regulates type I IFN expression in response to a variety of pathogenic stimuli and is a critical mediator of MyD88-dependent Toll-like receptor (TLR) signaling [[15-18]]. Proinflammatory cytokines elevated in the serum of lupus patients, that is IFN-α, interleukin (IL)-6, IL-12, and tumor necrosis factor (TNF)-α, are regulated by IRF5 [[16]]. In mice, the production of IFN-α/β and IL-6 in response to sera or IgG–RNA immune complexes (IC) from lupus

patients was shown to be Tlr7, Irf5, and Irf7 dependent [[19]]. These data support crotamiton the conventional wisdom that elevated IRF5 expression in SLE patients may drive disease development by causing aberrant production of type I IFN through TLR7 and/or TLR9 signaling that is activated by IC [[20, 21]]. Correlative data supporting this has been obtained in SLE patients demonstrating association of an IRF5 risk haplotype with IFN-α activity that was dependent on autoantibodies [[22]]. Recently, it was demonstrated that FcRIIb−/− and FcRIIb−/−Yaa mice lacking Irf5 had significantly decreased autoantibody production, limited glomerular IgG deposition, and enhanced survival [[23]]. Little mechanistic insight was provided for the protective Irf5−/− phenotype. A subsequent study demonstrated that IRF5 regulates transcription of the γ2a locus resulting in decreased autoantibody production [[24]]. Surprisingly, neither study directly addressed whether loss of Irf5 affected type I IFN expression [[23, 24]]. We hypothesized that loss of Irf5 would alter multiple aspects of autoimmunity due to its regulation of the pleiotropic cytokine type I IFN and other proinflammatory cytokines [[15-18]].

The differentiation and polarization of macrophages

have

The differentiation and polarization of macrophages

have been extensively studied, particularly with regard to transcriptional regulation. For instance, the PU.1 and C/EBP transcription factors are critical for the development of macrophages. M1 macrophage polarization by TLR ligands involves the activation of a set of transcription factors, such as NF-κB, AP-1, C/EBPβ, PU.1 and IFN-regulatory factors (IRFs) 6, 19. On the other hand, transcription factors such as STAT6 and peroxisome proliferator-activated receptor (PPAR)-γ are involved in the polarization of M2 macrophages 14, 20. However, recent studies have revealed that epigenetic regulation is also important for macrophage development and polarization. Epigenetic changes regulate diverse cellular functions including cellular differentiation, cell activation and transformation. Dynamic changes in DNA methylation and histone modifications R428 are associated with altered gene expression 21. Although the epigenetic control

of macrophage function is not fully understood, Selumetinib we here discuss several mechanisms that have become clearer recently. Methylation of the cytosine in the CpG dinucleotide is mediated by a number of DNA methyltransferases, and is generally associated with gene silencing by affecting the recruitment of transcription factors, which results in cellular differentiation 22. Global changes in DNA methylation in hematopoietic cell differentiation have been studied in the mouse BM 23, revealing that myeloid commitment from hematopoietic stem cells is associated with reduced global DNA methylation as compared with that during lymphoid commitment. After treatment with a DNA methyltransferase inhibitor, progenitors are skewed toward myeloid rather than lymphoid cells, suggesting that control of DNA methylation is important for myeloid cell differentiation. Although DNA methylation analysis in mature macrophages has not been reported, it was shown that the methylated

CpGs on the CD209 promoter were drastically demethylated following differentiation from monocytes to dendritic cells 24. Consistently, the expression of CD209, which encodes P-type ATPase DC-SIGN, increased upon differentiation in human cells, suggesting that loss of the inhibitory epigenetic mark contributes to the differentiation of monocytes. Further studies in macrophages will be necessary for uncovering the role of DNA methylation regulation in macrophage polarization. It is widely accepted that histone modifications such as methylation, acetylation and phosphorylation are important for controlling gene expression, and specific combinations of modifications are considered to constitute a “histone code”. Histone acetylation marks are enriched in activated chromatin regions 25.