Early life stress‐induced histone acetylations correlate with activation of the synaptic plasticity genes Arc and Egr1 in the mouse hippocampus

Early life stress (ELS) programs the developing organism and influences the development of brain and behavior. We tested the hypothesis that ELS‐induced histone acetylations might alter the expression of synaptic plasticity genes that are critically involved in the establishment of limbic brain circuits. Maternal separation (MS) from postnatal day 14–16 was applied as ELS and two immediate early genes underlying experience‐induced synaptic plasticity, Arc and early growth response 1 (Egr1) were analyzed. We show here that repeated ELS induces a rapid increase of Arc and Egr1 in the mouse hippocampus. Furthermore, immunoblotting revealed that these changes are paralleled by histone modifications, reflected by increased acetylation levels of H3 and H4. Most importantly, using native Chromatin immunoprecipitation quantitative PCR (nChIP‐qPCR), we show for the first time a correlation between elevated histone acetylation and increased Arc and Egr1 expression in response to ELS. These rapid epigenetic changes are paralleled by increases of dendritic complexity and spine number of hippocampal CA3 pyramidal neurons in ELS animals at weaning age. Our results are in line with our working hypothesis that ELS induces activation of synaptic plasticity genes, mediated by epigenetic mechanisms. These events are assumed to represent early steps in the adaption of neuronal networks to a stressful environment.     

The complete mitochondrial genome of Talpa martinorum (Mammalia: Talpidae), a mole species endemic to Thrace: genome content and phylogenetic considerations

Genetica - The complete mitogenome sequence of Talpa martinorum, a recently described Balkan endemic mole, was assembled from next generation sequence data. The mitogenome is similar to that of the...     

Prevalence of Prostate Cancer in High Boron-Exposed Population: A Community-Based Study

We investigated the possible relationship between boron exposure and prostate cancer (PCa) for men living and being employed at boron mines in villages with rich boron minerals. Out of 456 men studied, 159 were from villages with rich boron sources and boron levels in drinking water of >1?mg?L(-1) and these men formed the study group, while 63 from villages with rich boron sources and boron levels in drinking water of <1?mg?L(-1) were enrolled into control group?1. A further 234 subjects from other villages with no boron mines were considered as control group?2. Prostate specific antigen (PSA) levels could be obtained from a total of 423 men. Urinary boron concentration as an indicator of boron exposure in 63 subjects, prostatic volumes by transrectal ultrasonography in 39 subjects, and prostatic biopsies in 36 subjects were obtained for study and control groups. The daily boron exposure was calculated according to urinary boron levels. Although there was no significant difference among the groups in terms of total PSA levels, the number of subjects with tPSA ≥2.5 and tPSA ≥10.0?ng?dL(-1) prostatic volumes in men whose prostates were biopsied (p?相似文献   

Identification of potential serodiagnostic and subunit vaccine antigens by antibody profiling of toxoplasmosis cases in Turkey

Toxoplasmosis, caused by infection of the protozoan parasite Toxoplasma gondii, is associated with mild disease in healthy individuals, whereas individuals with depressed immunity may develop encephalitis, neurologic disorders, and other organ diseases. Women who develop acute toxoplasmosis during pregnancy are at risk of transmitting the infection to the fetus, which may lead to fetal damage. A diagnosis is usually confirmed by measuring IgG, or IgM where it is important to determine the onset of infection. A negative IgM result essentially excludes acute infection, whereas a positive IgM test is largely uninterpretable because IgM can persist for up to 18 months after infection. To identify antigens for improved diagnosis of acute infection, we probed protein microarrays displaying the polypeptide products of 1357 Toxoplasma exons with well-characterized sera from Turkey. The sera were classified according to conventional assays into (1) seronegative individuals with no history of T. gondii infection; (2) acute infections defined by clinical symptoms, high IgM titers, and low avidity IgG; (3) chronic/convalescent cases with high avidity IgG but persisting IgM; (iv) true chronic infections, defined by high avidity IgG and no IgM. We have identified 38 IgG target antigens and 108 IgM target antigens that can discriminate infected patients from healthy controls, one or more of which could form the basis of a 'tier-1' test to determine current or previous exposure. Of these, three IgG antigens and five IgM antigens have the potential to discriminate chronic/IgM persisting or true chronics from recent acutely infected patients (a 'tier-2' test). Our analysis of the antigens revealed several enriched features relative to the whole proteome, which include transmembrane domains, signal peptides, or predicted localization at the outer membrane. This is the first protein microarray survey of the antibody response to T. gondii, and will help in the development of improved serodiagnostics and vaccines.     

Discriminating between the activities of human cathepsin G and chymase using fluorogenic substrates

Cathepsin G (CG) (EC 3.4.21.20) and chymase (EC 3.4.21.39) are two closely-related chymotrypsin-like proteases that are released from cytoplasmic granules of activated mast cells and/or neutrophils. We investigated the potential for their substrate-binding subsites to discriminate between their substrate specificities, aiming to better understand their respective role during the progression of inflammatory diseases. In addition to their preference for large aromatic residues at P1, both preferentially accommodate small hydrophilic residues at the S1' subsite. Despite significant structural differences in the S2' subsite, both prefer an acidic residue at that position. The Ala226/Glu substitution at the bottom of the CG S1 pocket, which allows CG but not chymase to accommodate a Lys residue at P1, is the main structural difference, allowing discrimination between the activities of these two proteases. However, a Lys at P1 is accommodated much less efficiently than a Phe, and the corresponding substrate is cleaved by β2-tryptase (EC 3.4.21.59). We optimized a P1 Lys-containing substrate to enhance sensitivity towards CG and prevent cleavage by chymase and β2-tryptase. The resulting substrate (ABZ-GIEPKSDPMPEQ-EDDnp) [where ABZ is O-aminobenzoic acid and EDDnp is N-(2,4-dinitrophenyl)-ethylenediamine] was cleaved by CG but not by chymase and tryptase, with a specificity constant of 190 mM(-1)·s(-1). This allows the quantification of active CG in cells or tissue extracts where it may be present together with chymase and tryptase, as we have shown using a HMC-1 cell homogenate and a sputum sample from a patient with severe asthma.     

Catalytic Activity and Inhibition of Wegener Antigen Proteinase 3 on the Cell Surface of Human Polymorphonuclear Neutrophils

Proteinase 3 (Pr3), the main target of anti-neutrophil cytoplasmic antibodies, is a neutrophil serine protease that may be constitutively expressed at the surface of quiescent circulating neutrophils. This raises the question of the simultaneous presence in the circulation of constitutive membrane-bound Pr3 (mPr3) and its plasma inhibitor α1-protease inhibitor (α1-Pi). We have looked at the fate of constitutive mPr3 at the surface of circulating blood neutrophils and of induced mPr3 on triggered neutrophils. We found significant Pr3 activity at the surface of activated neutrophils but not at the surface of quiescent neutrophils whatever the constitutive expression. This suggests that constitutive mPr3 is enzymatically inactive or its active site is not accessible to the substrate. Supporting this conclusion, we have not been able to demonstrate any interaction between constitutive mPr3 and α1-Pi, whereas induced mPr3 is cleared from the cell surface when activated cells are incubated with this inhibitor. But, unlike membrane-bound elastase that is also cleared from the surface of activated cells, mPr3 remained bound to the membrane when inhibited by elafin or by a low molecular weight chloromethyl ketone inhibitor, which shows that it binds more tightly to the neutrophil membrane. mPr3 may thus be present at the surface of circulating neutrophils in an environment replete with α1-Pi. The permanent presence of inactive Pr3 at the surface of quiescent neutrophils may explain why Pr3 is a major target of anti-neutrophil cytoplasmic antibodies, whose binding activates neutrophils and triggers inflammation, as in Wegener granulomatosis.Proteinase 3 (Pr3)³ is a neutral serine protease (NSP) that is stored in the granules of circulating neutrophils (1, 2) and has been more recently located within secretory vesicles (3). Pr3, like its homologues neutrophil elastase (HNE) and cathepsin G (CG), participates in the intracellular degradation of phagocytized pathogens at inflammatory sites in combination with microbicidal peptides and the membrane-associated NADPH oxidase system (4). All three NSPs are also released from activated neutrophils and help destroy extracellular matrix components and regulate innate immunity, inflammation, and infection (5). Although NSPs are structurally and functionally related and are synthesized similarly (6), Pr3 differs from the other two by its bimodal, genetically determined, expression on the cell surface of quiescent neutrophils (7, 8). Thus, each individual has two subsets of neutrophils, mPr3^high and mPr3^low, whereas HNE and CG are not present in significant amount at the surface of resting neutrophils. Pr3 also differs from the other two NSPs by its storage within secretory vesicles that readily fuse with the plasma membrane (3). But it is not clear that this explains why Pr3 is constitutively expressed at the surface of a subpopulation of quiescent neutrophils. Supporting this hypothesis, it has been recently demonstrated that CD177 (also called NB1), which is also stored in secretory vesicles and has a bimodal membrane expression, is present on the plasma membrane of the same subset of neutrophils as Pr3 (9, 10).The presence of Pr3 on the surface of quiescent neutrophils would favor neutrophil activation by anti-neutrophil cytoplasmic antibodies (ANCAs) during Wegener granulomatosis (WG) (11). This explains why this protease, unlike HNE and CG, is a risk factor for this autoimmune disease characterized by necrotizing inflammation particularly of the respiratory tract, kidneys, and by small vessel vasculitis (12). Binding of anti-Pr3 antibodies to tumor necrosis factor-α-primed neutrophils is impaired by α1-Pi (13), which suggests that mPr3 activity and the protease-antiprotease balance are involved in neutrophil activation during WG.Measuring the Pr3 activity on the cell surface of quiescent and activated neutrophils requires specific substrates of Pr3 that were not available until recently (14, 15). Because of the storage of Pr3 in both secretory vesicles and primary granules and the presence of constitutive Pr3 at the surface of resting neutrophils, we have determined whether both constitutive and induced Pr3 are enzymatically active when bound to the cell surface, and how they are regulated by protease inhibitors. Pr3 activity is controlled by a variety of natural inhibitors, the most important of which are α1-Pi, elafin/trappin-2, and monocyte neutrophil elastase inhibitor. But none is specific for this protease, so it cannot be specifically targeted in vivo or ex vivo. We have previously shown that mHNE is rapidly cleared from the surface of activated neutrophils by α1-Pi and by EPI-hNE4, a low molecular weight recombinant inhibitor, with which it forms soluble, inactive complexes (16, 17). This raises the question of how mPr3 can be targeted by autoantibodies in the presence of α1-Pi, which efficiently inhibits its soluble form, although more slowly than it does HNE (18). We answered this question by investigating the enzymatic properties of mPr3 and its sensitivity to inhibitors. The behavior of mPr3 clearly differs from that of mHNE, which explains why it may be a preferential target for autoantibodies and so contributes to the pathogenicity of Wegener disease.     

Autophagy-related gene, TdAtg8, in wild emmer wheat plays a role in drought and osmotic stress response

An autophagy-related gene Atg8 was cloned for the first time from wild emmer wheat, named as TdAtg8, and its role on autophagy under abiotic stress conditions was investigated. Examination of TdAtg8 expression patterns indicated that Atg8 expression was strongly upregulated under drought stress, especially in the roots when compared to leaves. LysoTracker(?) red marker, utilized to observe autophagosomes, revealed that autophagy is constitutively active in Triticum dicoccoides. Moreover, autophagy was determined to be induced in plants exposed to osmotic stress when compared to plants grown under normal conditions. Functional studies were executed in yeast to confirm that the TdATG8 protein is functional, and showed that the TdAtg8 gene complements the atg8?::kan MX yeast mutant strain grown under nitrogen deficiency. For further functional analysis, TdATG8 protein was expressed in yeast and analyzed using Western immunoblotting. Atg8-silenced plants were exposed to drought stress and chlorophyll and malondialdehyde (MDA) content measurements demonstrated that Atg8 plays a key role on drought stress tolerance. In addition, Atg8-silenced plants exposed to osmotic stress were found to have decreased Atg8 expression level in comparison to controls. Hence, Atg8 is a positive regulator in osmotic and drought stress response.     

Effect of progesterone on DPPC membrane: evidence for lateral phase separation and inverse action in lipid dynamics

Interactions of progesterone with zwitterionic dipalmitoyl phosphatidylcholine (DPPC) multilamellar liposomes were investigated as a function of temperature and progesterone concentration by using three non-invasive techniques namely Fourier transform infrared spectroscopy, turbidity at 440 nm, and differential scanning calorimetry. The results reveal that progesterone changes the physical properties of DPPC bilayers by decreasing the main phase-transition temperature, abolishing the pre-transition, broadening the phase-transition profile, disordering the system both in gel and liquid crystalline phase, increasing the dynamics at low concentrations whereas stabilizing the membrane at high concentrations, and inducing phase separation. Progesterone does not change the hydration of the CO groups, while it strengthens the hydrogen bonding between the PO2- groups of lipids and the water molecules around.