Lysine acetyltransferase 6A maintains CD4+ T cell response via epigenetic reprogramming of glucose metabolism in autoimmunity

Augmented CD4+ T cell response in autoimmunity is characterized by extensive metabolic reprogramming. However, the epigenetic molecule that drives the metabolic adaptation of CD4+ T cells remains largely unknown. Here, we show that lysine acetyltransferase 6A (KAT6A), an epigenetic modulator that is clinically associated with autoimmunity, orchestrates the metabolic reprogramming of glucose in CD4+ T cells. KAT6A is required for the proliferation and differentiation of proinflammatory CD4+ T cell subsets in vitro, and mice with KAT6A-deficient CD4+ T cells are less susceptible to experimental autoimmune encephalomyelitis and colitis. Mechanistically, KAT6A orchestrates the abundance of histone acetylation at the chromatin where several glycolytic genes are located, thus affecting glucose metabolic reprogramming and subsequent CD4+ T cell responses. Treatment with KAT6A small-molecule inhibitors in mouse models shows high therapeutic value for targeting KAT6A in autoimmunity. Our study provides novel insights into the epigenetic programming of immunometabolism and suggests potential therapeutic targets for patients with autoimmunity.

[Design for online monitoring of occupational hazard factors based on internet of things]

At present, there are disadvantages with the detection for occupational hazard factors, such as insufficient monitoring data, poor timeliness, weak representativeness, long detection cycles, and inability to continuously monitor. Taking advantages of internet of things technology, an online monitoring platform for occupational hazard factors has been designed. The platform collects the concentration (intensity) of hazard factors through sensors, transmits the occupational hazards data collected online in realtime. The online monitoring cloud center for occupational hazard factors processes and analyzes online monitoring data in realtime, stores the hazard factors data to form database management, and provides user application services to form an intelligent online monitoring service model for occupational hazard factors. Based on the online monitoring platform of occupational hazard factors, multi-level government health supervision departments and employers can grasp the status of hazard factors in real time, which is conducive to improving the level of occupational hazard supervision.

Theabrownin Induces Cell Apoptosis and Cell Cycle Arrest of Oligodendroglioma and Astrocytoma in Different Pathways

Theabrownin (TB), a natural compound present in the fresh leaves of green tea, is a potential antitumor agent. However, so far whether and how TB affects glioma is unclear. In this study, we investigated the effect of TB on astroglioma and oligodendroglioma cells. Surprisingly, TB significantly reduced the viabilities of HOG and U251 cells in a dose-dependent manner, which was accompanied by the upregulation of active-Casp-3, Bax, and PTEN; meanwhile, the antiapoptotic gene Bcl-2 was downregulated. In addition, TB treatment induced cell cycle arrest at the G1 and G2/M phases in HOG and U251 cells, respectively. TB treatment caused the downregulating of c-myc, cyclin D, CDK2, and CDK4 and upregulating of p21 and p27 in the HOG cell, while TB increased P53, p21, and p27 levels and decreased the levels of cell cycle regulator proteins such as CDK and cyclin A/B in the U251 cells. Therefore, the c-myc- and P53-related mechanisms were proposed for cell cycle arrest in these two glioma cell lines, respectively. Overall, our findings indicated that TB could be a novel candidate drug for the treatment of gliomas.

Osteogenic Treatment Initiating a Tissue-Engineered Cartilage Template Hypertrophic Transition

Hypertrophic chondrocytes play a critical role in endochondral bone formation as well as the progress of osteoarthritis (OA). An in vitro cartilage hypertrophy model can be used as a platform to study complex molecular mechanisms involved in these processes and screen new drugs for OA. To develop an in vitro cartilage hypertrophy model, we treated a tissue-engineered cartilage template, living hyaline cartilaginous graft (LhCG), with osteogenic medium for hypertrophic induction. In addition, endothelial progenitor cells (EPCs) were seeded onto LhCG constructs to mimic vascular invasion. The results showed that osteogenic treatment significantly inhibited the synthesis of endostatin in LhCG constructs and enhanced expression of hypertrophic marker-collagen type X (Col X) and osteogenic markers, as well as calcium deposition in vitro. Upon subcutaneous implantation, osteogenic medium-treated LhCG constructs all stained positive for Col X and showed significant calcium deposition and blood vessel invasion. Col X staining and calcium deposition were most obvious in osteogenic medium-treated only group, while there was no difference between EPC-seeded and non-seeded group. These results demonstrated that osteogenic treatment was of the primary factor to induce hypertrophic transition of LhCG constructs and this model may contribute to the establishment of an in vitro cartilage hypertrophy model.

Search for a light sterile neutrino at Daya Bay

A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.

Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay

A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9  GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3)  eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.

Role of cigarette filter on the risk of oral cancer: a case-control study in a Chinese population

OBJECTIVE

To determine the role of cigarette filter on the incidence risk of oral squamous cell cancer among male smokers in a Chinese population.

SUBJECTS AND METHODS

A multicentric hospital-based case-control study was applied. Three hundred and nineteen male cases and 428 male controls matching for age ( ± 3 years) were identified from January 2008 to December 2010. Detailed smoking histories were obtained by interviews. Logistic regression model was used to compare the influence of filter and non-filter cigarettes on oral cancer risk.

RESULTS

The adjusted odd ratios (ORs) for oral cancer were 1.30 (95% CI 1.15, 1.48) of filter cigarette smokers, 2.06 (95% CI 1.17, 3.62) of non-filter cigarette smokers, and 1.73 (95% CI 1.33, 2.25) of mixed smokers, as compared with non-smokers. When classified current smokers according to smoking pack year, the ORs of mixed smokers were 2.27 (95% CI 1.06, 4.85) in <20 pack year, 0.81 (95% CI 0.57, 1.14) in 20-39 pack year, and 0.86 (95% CI 0.57, 1.29) in ≥ 40 pack year, as compared to filter cigarette smokers.

CONCLUSIONS

The protective effect against oral cancer of cigarette filter was limited, restricted to smokers of small amount of smoking accumulation. For most smokers, the difference was non-significant between filter and non-filter cigarettes on the risk of developing oral cancer.

Observation of electron-antineutrino disappearance at Daya Bay

The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.

Cloning, expression, purification, and characterization of rat MMP-12

Macrophage metalloelastase (MMP-12) is implicated in the pathology of many diseases such as emphysema, aortic lesions and cancer. Recently, MMP-12 was cloned and purified from mouse and human macrophages. We report here the expression of the full-length and catalytic domain of rat MMP-12 in Escherichia coli and characterization of the purified enzyme. Inclusion bodies of expressed rat MMP-12 catalytic domain were denatured and refolded using a new method, and then affinity purified to near homogeneity with zinc-chelating Sepharose. The purified rat MMP-12 catalytic domain was highly active in digesting substrates, having a K(m) of 12 microM and optimal pH of 7.5--8.5. During investigation of natural substrate specificity, we found that rat MMP-12 catalytic domain was able to completely degrade collagen-V, partially degrade collagen-I, but it was unable to digest collagen-IV. The enzyme could also degrade osteonectin, vitronectin, and fibronectin, but not laminin and albumin. The catalytic properties and natural substrate specificity of rat MMP-12 catalytic domain differed from those of human MMP-12 catalytic domain.

Simple, rapid enzyme-linked immunosorbent assay (ELISA) for the determination of rat osteocalcin

Determination of the concentration of osteocalcin in rat serum is frequently performed using a commercially available radioimmunoassay (RIA). However, this assay takes 3 days to complete, uses radioactive material, and has a narrow linear range. The limited range of the RIA makes it necessary to test multiple dilutions of the sample which frequently results in values that differ, depending on the dilution. In order to overcome these limitations, we have developed an ELISA that utilizes the same standards and anti-rat osteocalcin antiserum, as is used in the RIA. The principle of the ELISA is that the osteocalcin in the sample competes with osteocalcin previously immobilized on a microtiter plate to bind to the available anti-rat osteocalcin antibodies. The amount of antibody bound to the immobilized osteocalcin is determined colorimetrically using a secondary antibody coupled to alkaline phosphatase. This ELISA has a three-log linear response with a sensitivity of 0.1-0.15 ng/ml and intra- and interassay coefficient of variance (CV) values of less than 10%. Most importantly, the assay is rapid and only requires a 2-hour incubation of the sample with the antiserum. The incubation time is important since we and others have observed a significant decrease in the osteocalcin level from serum samples incubated for long periods of time with the antiserum, presumably due to degradation of the osteocalcin. In general, the commercially available RIA gives osteocalcin values that are one-half to one-fourth that of the ELISA because the RIA requires a 48-hour incubation time.

Study on peripheral blood lymphocytes chromosome abnormality of people exposed to cadmium in environment

Chromosome aberration (CA) and micronucleus (MN) tests were applied to investigate peripheral blood lymphocytes in 56 people environmentally exposed to cadmium (Cd) for a period up to 30 years, and in 10 unexposed people as controls. As indicator of body-load of Cd, urinary Cd (UCd) concentrations were measured simultaneously. The people in polluted villages were divided into four groups according to various levels of UCd concentrations: -2.5, 2.5-, 5.0-, 10.0- (micrograms/l). There was significant difference in MN rates between the exposed and control groups (3.47, 5.06, 8.06, 12.75/1000 for the exposed groups respectively, and 3.10/1000 for the controls), and significant correlation between MN rates and UCd was observed. Although no marked difference in CA rates was noted between UCd 5.0- and 10.0- groups, there was significant difference in CA rates between the exposed and control groups (3.07, 5.21, 7.21, 8.50% for exposed groups respectively, and 2.33% for the controls) and significant correlation between CA rates and UCd. CA was presented mainly in the form of chromatid and chromosome gaps and breaks. Together with our another study "An Investigation on Human Health Effects by Environmental Cadmium Pollution", the results suggest that Cd may injure human chromosomes and that the damage appears to be concentrated on cytogenetic material and may happen earlier than renal disfunction.

Design of organic molecules with large two-photon absorption cross sections

A strategy for the design of molecules with large two-photon absorption cross sections, delta, was developed, on the basis of the concept that symmetric charge transfer, from the ends of a conjugated system to the middle, or vice versa, upon excitation is correlated to enhanced values of delta. Synthesized bis(styryl)benzene derivatives with donor-pi-donor, donor-acceptor-donor, and acceptor-donor-acceptor structural motifs exhibit exceptionally large values of delta, up to about 400 times that of trans-stilbene. Quantum chemical calculations performed on these molecules indicate that substantial symmetric charge redistribution occurs upon excitation and provide delta values in good agreement with experimental values. The combination of large delta and high fluorescence quantum yield or triplet yield exhibited by molecules developed here offers potential for unprecedented brightness in two-photon fluorescent imaging or enhanced photosensitivity in two-photon sensitization, respectively.

Biochemistry of the renal V-ATPase

In most eukaryotic cells, vacuolar H(+)-ATPases (V-ATPases) are present primarily or exclusively in intracellular membrane compartments, functioning in the acidification of the endocytic and secretory vacuolar apparatus necessary for constitutive cell function. V-ATPases also participate in renal hydrogen ion secretion in both the proximal and distal nephron, residing at high concentrations on the plasma membrane, where they are regulated physiologically to maintain the acid-base balance of the organism. Recent experiments have begun to reveal how the kidney controls transcellular proton transport while still maintaining acidification of intracellular compartments. Control may occur by recruitment of proton pumps to or away from the plasma membrane. The proton-transporting plasma membrane of intercalated cells is a specialized apparatus that translocates the enzyme between an intracellular membrane pool and the plasma membrane in response to physiological stimuli. Regulation may also occur by changes in the kinetics of the V-ATPase. V-ATPases are a family of structurally similar enzymes which differ in the composition of specific subunits. Cytosolic regulatory enzymes present in renal cells may preferentially affect V-ATPases in selective membrane compartments.

The induction and suppression of prostaglandin H2 synthase (cyclooxygenase) in human monocytes

We report here that the bacterial lipopolysaccharide endotoxin induces human blood monocytes in a time- and dose-dependent manner to release prodigious amounts of prostaglandins with thromboxane A2, the major metabolite formed. Cells responded to as little as 1 ng/ml lipopolysaccharide to release prostaglandin E2 and thromboxane A2 with maximal stimulation at 10 micrograms/ml. Lipopolysaccharide was found to induce increased activity of cyclooxygenase enzyme without affecting the activities of phospholipase and thromboxane synthase or the formation of 5-lipoxygenase products (e.g. leukotriene B4). The glucocorticoid dexamethasone completely blocked the lipopolysaccharide-induced prostanoid release by inhibiting the activity of monocyte cyclooxygenase. Dexamethasone did not affect phospholipase and thromboxane synthase activities or leukotriene formation. Immunoprecipitation of [35S]methionine-labeled cyclooxygenase confirmed that the effect of lipopolysaccharide and dexamethasone on the monocyte prostanoid production could be attributed to an increase or decrease, respectively, in cellular cyclooxygenase de novo synthesis.

[Studies on the possible causes of decreasing NK cell activity in tumor-bearing mice. I. The number of NK cells in the spleens of tumor-bearing mice is higher than that in normal mice]

In studies of viral immunotherapy of cancer, we found that NK cell activity in tumor-bearing mice was usually below the normal level, a universal phenomenon in tumor-bearing animals and patients. Our data show that the depressed NK cell activity in tumor-bearing mice was not due to a decrease of NK cell number. The percentage of NK cells in the spleens of tumor-bearing mice was much higher than that in normal mice. Using morphological and 3H-TdR uptake methods, we found that there were many NK blast cells in the spleens of tumor-bearing mice, and blastogenesis was sustained up to the day of death.

[Studies on the possible causes of decreasing NK cell activity in tumor-bearing mice. II. Serum and peritoneal exudate from ascitic tumor-bearing mice suppress NK cell activity]

Previous studies showed that the depressed NK cell activity in tumor-bearing mice was not due to the decrease of NK cell number. The results of this report indicate that the depressed NK cell activity in tumor-bearing mice might be due to an inhibitory factor, which probably was secreted by tumor-cells. We found that sera and peritoneal exudates from S180 or P388 tumor-bearing mice were able to inhibit the normal NK cell activity. Spleen cells incubated with the peritoneal exudate for 24 hours before assay demonstrated significantly depressed NK activity. Treatment of peritoneal exudate with a large number of spleen cells did not alter the inhibitory effect of peritoneal fluid, indicating that the inhibitory factor might not be membrane antigen shedding from the tumor cells, but may be actively secreted by them.

Leukotriene A4 hydrolase: analysis of some human tissues by radioimmunoassay

Leukotriene A4 hydrolase was quantitated by radioimmunoassay, in extracts from eight human tissues. The enzyme was detectable in all tissues, with the highest level (2.6 mg per g soluble protein) in leukocytes, followed by lung and liver. The polyclonal antiserum did not cross-react with cytosolic epoxide hydrolase purified from mouse or human liver. When incubated with leukotriene A4, formation of leukotriene B4 was evident in all tissues. Furthermore, enzymatic formation of (5S,6R)-dihydroxy-7,9-trans-11,14-cis-eicosatetraenoic acid from leukotriene A4, was found in extracts from liver, kidney and intestines.

B-lymphocytic cell line Raji expresses the leukotriene A4 hydrolase gene but not the 5-lipoxygenase gene

The expression of LTA hydrolase and 5-lipoxygenase genes was studied in Raji cells, a Burkitt lymphoma derived B-cell line. Northern and Western blot analyses clearly showed the expression, both at the transcriptional and translational level, of the LTA4 hydrolase gene in these cells. However, expression of the 5-lipoxygenase gene was undetectable. Thus, the genes coding for the two enzymes required for biosynthesis of leukotriene B4 from arachidonic acid, 5-lipoxygenase and LTA4 hydrolase, were differentially expressed in the Raji cells.

Antileukemic effect of low-dose harringtonine

The effect of harringtonine (HA) in various concentrations on HL-60 was evaluated. 0.10 microgram/ml HA showed a strong cell killing effect, and 0.025 microgram/ml HA a weak differentiation induction accompanied by cell growth retardation. Differentiation induction did not occur in 5 other human leukemic cell lines. We consider that antileukemic effect of HA is cytotoxicity, not differentiation induction.

Leukotriene A4, conversion to leukotriene B4 in human T-cell lines

Human T-cell lines (HSB, MOLT-4 and CCRF-CEM) produced leukotriene B4 when incubated with leukotriene A4. The product was characterized by chromatographic properties, UV-spectroscopy and gas chromatography mass spectrometry. About 10 pmol of leukotriene B4 was obtained per 10(6) cells. When incubated with arachidonic acid plus the calcium ionophore A23187 however, no leukotriene B4 was found, indicating that the T-cell lines lack 5-lipoxygenase yet contain LTA4 hydrolase.

Molecular cloning and amino acid sequence of leukotriene A4 hydrolase

A cDNA clone corresponding to leukotriene A4 hydrolase was isolated from a human lung lambda gt11 expression library by immunoscreening with a polyclonal antiserum. Several additional clones from human lung and placenta cDNA lambda g11 libraries were obtained by plaque hybridization with the 32P-labeled lung cDNA clone. One of these clones has an insert of 1910 base pairs that contains the complete protein-coding region. From the deduced primary structure, leukotriene A4 hydrolase is a 610 amino and protein with a calculated molecular weight of 69,140. No apparent homologies with microsomal epoxide hydrolases were found. RNA blot analysis indicated substantial amounts of a discrete mRNA of approximately equal to 2250 nucleotides in lung tissue and leukocytes.