A Novel ELISA to Detect Methionine Sulfoxide−Containing Apolipoprotein A−I

Atherosclerosis manifests a state of increased oxidative stress characterized by comparable lipid and protein oxidation in the affected arterial wall. While oxidative modification of low density lipoprotein (LDL) has been extensively studied, increasing attention has been focused recently on oxidation of high-density lipoproteins (HDL) and its functional consequences in relation to atherosclerosis. Oxidative modification is thought to generate “dysfunctional” HDL that has lost anti-atherosclerotic activities, including the ability to remove cholesterol from lipid-laden cells. Therefore, there has been much interest in the detection of oxidized HDL. Unfortunately, available methods to detect oxidized HDL are limited at present, in part because oxidative modification of HDL is a complex process and ‘oxidized HDL’ is not a chemically defined entity. What is known however is that conversion of methionine (Met) residues of apolipoprotein (apo) A-I to methionine sulfoxide (MetO) is a process that occurs commonly as HDL undergoes oxidative modification. For example, human apoA-I+16 (containing MetO86 or MetO112) and apoA-I+32 (MetO86 plus MetO112) are generated when apoA-I reacts with lipid hydroperoxides formed as a consequence of the lipoprotein being exposed to 1e−oxidants. The formation of MetO in apoA−I induced by 2e−oxidants (i.e., hydrogen peroxide, hypochlorous acid or myeloperoxidase/hydrogen peroxide/chloride system) is associated with an impaired ability of the apolipoprotein to facilitate reactions relevant to reverse cholesterol transport. In addition, a previous study has suggested the plasma content of apoA-I+32 to be increased in certain subjects that have an increased risk to develop cardiovascular disease (CVD). Moreover, the MetO content in circulating, HDL−associated apoA−I is elevated in type 1 diabetes, a disorder commonly associated with increased oxidative stress and a risk factor for atherosclerosis. Therefore, in the present study, an existing HPLC method was applied to HDL samples from the Fletcher−Challenge study, a nested case control study, to test the potential usefulness of MetO-containing apoA-I as a marker of oxidative stress and/or CVD in a general population. Plasma samples whose HDL contained detectable apoA-I+16 and/or apoA-I+32 had significantly elevated levels of F2-isoprostanes, a marker of in vivo lipid oxidation, consistent with MetO-containing apoA-I being a useful marker of in vivo protein oxidation. Despite this however, there was no significant difference between controls and cases in their concentrations of HDL apoA-I+16 and apoA-I+32 or F2-isoprostanes, suggesting that markers of protein and lipid oxidation are not associated with the risk of coronary heart disease (CHD) in this general population. A limitation of the Fletcher−Challenge study was that only 22% of the 534 HDL samples analyzed contained apoA-I+16 and/or apoA-I+32. In addition, the HPLC−based method used is expensive and time−consuming and may lack the sensitivity needed for apolipoproteins to clinical studies. Thus, a mouse monoclonal anti-human apoA-I+32 antibody (MOA−1) was raised using HPLC−purified apoA-I+32 as immunogen. A sensitive ELISA was then developed using a commercial anti-human apoA-I monoclonal antibody as capture and biotinylated MOA−1 as detection antibody, respectively. The assay detected lipid−free HPLC−purified human apoA-I+32 in a concentration-dependent manner and with a significantly lower limit of detection (i.e., 3 ng/mL) than the HPLC method (1 μg/mL). The ELISA also detected lipid-free apoA-I modified by 2e-oxidants (hydrogen peroxide, hypochlorous acid, peroxynitrite), and HDL oxidized by 1e- or 2e-oxidants and present in buffer or human plasma. Moreover, the extent of recognition of MetO by MOA−1 increased with increasing numbers of MetO in apoA−I, as assessed by the experiments with H2O2−oxidized forms of apoA−I mutants, in which one, two or three Met residues were replaced with Leu. Their detection was concentration-dependent, reproducible, and exhibited a linear response over a physiologically plausible range of concentrations of oxidized HDL. In contrast, MOA-I failed to recognize native apoA-I, native apoA-II, apoA-I modified by hydroxyl radicals or metal ions, or LDL modified by 2e-oxidants. Furthermore, MOA−1 did not detect other Met−containing proteins oxidized by either hypochlorous acid or hydrogen peroxide. Taken together, the results showed that recognition of oxidized proteins by MOA−1 is limited to MetO contained in apoA−I. Finally, in a pilot study, plasma samples obtained from subjects with coronary artery disease (CAD) proven by angiography, and samples from CAD patients undergoing percutaneous coronary intervention (PCI) were analyzed by the ELISA. The preliminary data obtained showed elevated levels of MetO-containing apoA-I in plasma samples of CAD patients compared to those of corresponding control subjects. Unexpectedly, levels of MetOcontaining apoA-I decreased PCI compared to before PCI. A possible explanation for these results is that HDL−associated apoA−I become displaced by acute phase proteins, such as serum amyloid A, in response to PCI. In summary, the ELISA developed here specifically detects apoA-I containing MetO in HDL and human plasma. As such it may provide a useful tool for investigating the relationship between oxidized HDL and CAD

Ensuring Readability and Data-fidelity using Head-modifier Templates in Deep Type Description Generation

A type description is a succinct noun compound which helps human and machines to quickly grasp the informative and distinctive information of an entity. Entities in most knowledge graphs (KGs) still lack such descriptions, thus calling for automatic methods to supplement such information. However, existing generative methods either overlook the grammatical structure or make factual mistakes in generated texts. To solve these problems, we propose a head-modifier template-based method to ensure the readability and data fidelity of generated type descriptions. We also propose a new dataset and two automatic metrics for this task. Experiments show that our method improves substantially compared with baselines and achieves state-of-the-art performance on both datasets.Comment: ACL 201

Time-Course of the Effects of QSYQ in Promoting Heart Function in Ameroid Constrictor-Induced Myocardial Ischemia Pigs

We aim to investigate the therapeutic effects of QSYQ on a pig myocardial ischemia (MI) model and to determine its mechanism of action. The MI model was induced by Ameroid constriction of the left anterior descending coronary (LAD) in Ba-Ma miniature pigs. Four groups were created: model group, digoxin group, QSYQ group, and sham-operated group. Heart function, Ang II, CGMP, TXB2, BNP, and cTnT were evaluated before (3 weeks after operation: 0 weeks) and at 2, 4, and 8 weeks after drug administration. After 8 weeks of administration, the pigs were sacrificed for cardiac injury measurements. Pigs with MI showed obvious histological changes, including BNP, cTnT, Ang II, CGRP, TXB2, and ET, deregulated heart function, and increased levels of apoptotic cells in myocardial tissue. Treatment with QSYQ improved cardiac remodeling by counteracting those events. The administration of QSYQ was accompanied by a restoration of heart function and of the levels of Ang II, CGRP, TXB2, ET BNP, and cTnT. In addition, QSYQ attenuated administration, reduced the apoptosis, and decreased the level of TNF-α and active caspase-3. In conclusion, administration of QSYQ could attenuate Ameroid constrictor induced myocardial ischemia, and TNF-α and active caspase-3 seemed to be the critical potential target of QSYQ

Evaluation of Toxoplasma gondii as a live vaccine vector in susceptible and resistant hosts

<p>Abstract</p> <p>Background</p> <p><it>Toxoplasma gondii </it>has been shown to trigger strong cellular immune responses to heterologous antigens expressed by the parasite in the inbred mouse model <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>. We studied the immune response induced by <it>T. gondii </it>as an effective vaccine vector in chickens and rabbits.</p> <p>Results</p> <p><it>T. gondii </it>RH strain was engineered to express the yellow fluorescent protein (YFP) in the cytoplasm. A subcutaneous injection of the transgenic <it>T. gondii </it>YFP in chickens afforded partial protection against the infection of transgenic <it>E. tenella </it>YFP. <it>T. gondii </it>YFP induced low levels of antibodies to YFP in chickens, suggesting that YFP specific cellular immune response was probably responsible for the protective immunity against <it>E. tenella </it>YFP infection. The measurement of T-cell response and IFN-γ production further confirmed that YFP specific Th1 mediated immune response was induced by <it>T. gondii </it>YFP in immunized chickens. The transgenic <it>T. gondii </it>stimulated significantly higher YFP specific IgG titers in rabbits than in chickens, suggesting greater immunogenicity in a <it>T. gondii </it>susceptible species than in a resistant species. Priming with <it>T. gondii </it>YFP and boosting with the recombinant YFP can induce a strong anti-YFP antibody response in both animal species.</p> <p>Conclusions</p> <p>Our findings suggest that <it>T. gondii </it>can be used as an effective vaccine vector and future research should focus on exploring avirulent no cyst-forming strains of <it>T. gondii </it>as a live vaccine vector in animals.</p

Cardiac Substrate Utilization and Relationship to Invasive Exercise Hemodynamic Parameters in HFpEF

We conducted transcardiac blood sampling in healthy subjects and subjects with heart failure with preserved ejection fraction (HFpEF) to compare cardiac metabolite and lipid substrate use. We demonstrate that fatty acids are less used by HFpEF hearts and that lipid extraction is influenced by hemodynamic factors including pulmonary pressures and cardiac index. The release of many products of protein catabolism is apparent in HFpEF compared to healthy myocardium. In subgroup analyses, differences in energy substrate use between female and male hearts were identified

Traditional Chinese medicine for smoking cessation: An umbrella review of systematic reviews and meta-analysis of randomized controlled trials.

Traditional Chinese medicine (TCM) may have special advantages in facilitating smoking cessation, but consensus on effectiveness is lacking. We aim to comprehensively review, update, and refine current evidence on TCM effectiveness and safety. Nine databases were searched from their inception up to 28 February 2023. Systematic reviews (SRs) and meta-analysis of TCM for smoking cessation were identified and retrieved. Additional databases and hand searches of RCTs from included SRs were performed for data pooling. Cochrane ROB tools and AMSTAR-2 were used to evaluate the methodological quality of RCTs and SRs, respectively. RCT data are presented as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CI) using RevMan 5.4. Thirteen SRs involving 265 studies with 33081 participants were included. Among these 265 studies, 157 were duplicates (58.36%) and 52 were non-RCTs (19.62%). Combined with the remaining 56 RCTs identified through hand searches, 88 RCTs involving 12434 participants were finally included for data synthesis. All the SRs focused on acupoint stimulation, and the majority were of low or very low quality. The methodological quality of RCTs was either unclear or high risk. For continuous abstinence rate, TCM external interventions were better than placebo in 6 months to 1 year (RR=1.60; 95% CI: 1.14-2.25; I =27%; n=5533 participants). Compared with placebo, TCM external application was effective in reducing nicotine withdrawal symptoms, and the effect was gradually stable and obvious in the fourth week (MD= -4.46; 95% CI: -5.43 - -3.49; n=165 participants). Twelve RCTs reported adverse events as outcome indicators for safety evaluation, and no serious adverse events occurred. Despite the methodological limitations of the original studies, our review suggests that TCM intervention shows potential effectiveness on the continuous abstinence rate. Extending the intervention time can enhance the effect of TCM on nicotine withdrawal symptoms. Referred to adverse events, more data for safety evaluation are required. [Abstract copyright: © 2023 Lu CL. et al.