Suppressive effect of epigallocatechin‐3‐O‐gallate on endoglin molecular regulation in myocardial fibrosis in vitro and in vivo

Epigallocatechin‐3‐O‐gallate (EGCG), derived from green tea, has been studied extensively because of its diverse physiological and pharmacological properties. This study evaluates the protective effect of EGCG on angiotensin II (Ang II)‐induced endoglin expression in vitro and in vivo. Cardiac fibroblasts (CFs) from the thoracic aorta of adult Wistar rats were cultured and induced with Ang II. Western blotting, Northern blotting, real‐time PCR and promoter activity assay were performed. Ang II increased endoglin expression significantly as compared with control cells. The specific extracellular signal‐regulated kinase inhibitor SP600125 (JNK inhibitor), EGCG (100 μM) and c‐Jun N‐terminal kinase (JNK) siRNA attenuated endoglin proteins following Ang II induction. In addition, pre‐treated Ang II‐induced endoglin with EGCG diminished the binding activity of AP‐1 by electrophoretic mobility shift assay. Moreover, the luciferase assay results revealed that EGCG suppressed the endoglin promoter activity in Ang II‐induced CFs by AP‐1 binding. Finally, EGCG and the JNK inhibitor (SP600125) were found to have attenuated endoglin expression significantly in Ang II‐induced CFs, as determined through confocal microscopy. Following in vivo acute myocardial infarction (AMI)‐related myocardial fibrosis study, as well as immunohistochemical and confocal analyses, after treatment with endoglin siRNA and EGCG (50 mg/kg), the area of myocardial fibrosis reduced by 53.4% and 64.5% and attenuated the left ventricular end‐diastolic and systolic dimensions, and friction shortening in hemodynamic monitor. In conclusion, epigallocatechin‐3‐O‐gallate (EGCG) attenuated the endoglin expression and myocardial fibrosis by anti‐inflammatory effect in vitro and in vivo, the novel suppressive effect was mediated through JNK/AP‐1 pathway.     

两个不同启动子及其组合对碱性蛋白酶AprE异源表达的影响

背景:碱性蛋白酶(alkaline protease)是一种具有广泛用途的工业酶制剂,其发酵活力目前仍不能满足工业生产需要。目的:旨在通过优化启动子及其组合来提高Bacillus subtilis WB600中碱性蛋白酶AprE的产量。方法:以Bacillus subtilis WB600为出发菌株,成功构建了含有4种不同类型启动子(P1、P2、P-1-2、P-2-1)的碱性蛋白酶AprE表达菌株。结果:含不同启动子的4株重组菌均可成功表达碱性蛋白酶,发酵48h,含单一启动子P2的重组菌株表达碱性蛋白酶的活力为4 041U/ml,是P1的1. 23倍。双启动子重组菌B. subtilis WB600/P-2-1-aprE表达的酶活性最高,是双启动子P-1-2的1. 35倍,达到了6 125U/ml。结论:为工业化高产碱性蛋白酶提供了一种有效策略。     

Pollination in Lilium sargentiae (Liliaceae) and the first confirmation of long‐tongued hawkmoths as a pollinator niche in Asia

The geographical distribution of pollinators is an important factor determining the biogeographical pattern of floral evolution and diversification. In Africa, a guild of plant species has converged in a floral syndrome for pollination by long‐tongued hawkmoths (predominantly Agrius convolvuli). It is hypothesized that such floral convergence could track the geographical distribution of long‐tongued hawkmoths, so it may not be confined to Africa. We investigated the pollination biology of Lilium sargentiae E. H. Wilson, which is endemic to China and exhibits traits suggestive of long‐tongued hawkmoth pollination. Lilium sargentiae was visited by A. convolvuli as well as small beetles (Nitidulidae) but pollination was mostly or totally effected by the moth. It was consistent with other hawkmoth‐pollinated plants in terms of floral tube length, nectar traits, tepal reflectance, and scent composition. We present the first experimental evidence for the hypothesis proposed above and for hawkmoth pollination in the widespread and ornamentally and economically important genus Lilium L. in a natural habitat. Our findings imply that long‐tongued hawkmoths (especially the extremely widespread A. convolvuli) as a distinctive pollinator niche may have underlain the evolution of long‐tubed (>8 cm) flowers across different continents.     

Baseline susceptibility of Asian corn borer (Ostrinia furnacalis (Guenée)) populations in Vietnam to Cry1Ab insecticidal protein

Susceptibility of Asian corn borer (ACB), Ostrinia furnacalis (Guenée) to Bacillus thuringiensis (Bt) Cry1Ab protein was studied between 2015 and 2016 with 11 ACB populations, collected from various geographical regions in Vietnam. A concentration range of Cry1Ab from 0.20 to 26.10 ng/cm² of diet was evaluated against F₁ ACB neonates using diet surface-overlay bioassays. Mortality data was recorded daily until seven days after infestation. Growth inhibition was recorded at the end of seven days. The median lethal concentration (LC₅₀) varied ≈3-fold among the different populations, ranging from 0.58 to 1.83 ng/cm² of diet with an overall mean of 0.86 ng/cm² of diet. Even the lowest concentration of 0.20 ng/cm² caused 73.53% growth inhibition. >90% growth inhibition was achieved at 0.82 ng/cm² or higher concentrations. The results reflect natural variation in Bt susceptibility among ACB populations rather than variation caused by prior exposure to selection pressures. LC₉₉ value (17.26 ng/cm²) was generated by pooling mortality data across different populations. The upper fiducial limit of LC₉₉ (24.38 ng/cm²) could be a potential diagnostic dose for future resistance monitoring programs. The findings from this study suggest that ACB populations in Vietnam are highly susceptible to Cry1Ab protein. This is the first report of Cry1Ab susceptibility of different ACB populations in Vietnam and will serve as a baseline for future resistance monitoring work.     

A pre-targeting strategy for imaging glucose metabolism using technetium-99m labelled dibenzocyclooctyne derivative

During the last four decades, nuclear medicine has undergone enormous growth, and positron emission tomography (PET) has been in the driving seat for most of the time. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) is the most widely used agent for the detection of hibernating myocardium and metabolically active cancer tissue. But its cost and limited availability are the main limitations. For a long time different researchers and groups of pharmacists have tried to label glucose with a cheaper and long-acting radionuclide like ^99mTc. However, they failed to achieve this goal owing to the chemical complexity of ^99mTc and the lack of maintaining the physiological activity of diagnostic compounds. A pre-targeting strategy based on strain-promoted [3 + 2] azide-alkyne cycloaddition (SPAAC) reaction was applied to solve this problem. Functional click synthons were synthesized: 2-azido-2-deoxy-d-glucose (GlucN₃) as a glucose analogue, and N- (2- (2- (2- (bis (pyridin-2-ylmethyl) amino) ethoxy) ethoxy) ethyl-2- (6H-11,12-didehydrodibenzo [a,e] cycloocten-5-ylideneaminooxy) acetamide (C7) as a ^99mTc(CO)₃ labeling and azido-binding group. The results of biodistribution experiments in mice bearing S180 tumor show the relatively high tumor/blood ratio (up to 2.95) and tumor/muscle ratio (up to 6.37), and both of them decreases significantly in the glucose blocking experiment. It indicates that GlucN₃ behaves similarly to glucose and that in vivo SPAAC reactions can occur effectively. It is supposed that this pre-targeting strategy can indeed enhance target specificity and may be used for glucose metabolism imaging in tumor diagnosis.     

Leucine ureido derivatives as aminopeptidase N inhibitors using click chemistry. Part II

Aminopeptidase N (APN) has been proved to be deeply associated with cancer angiogenesis, metastasis and invasion. Therefore, APN gains increasing attention as a promising anti-tumor target. In the current study, we report the design, synthesis, biological evaluation and structure-activity relationship of one new series of leucine ureido derivatives containing the 1,2,3-triazole moiety. Among them, compound 31f was identified as the best APN inhibitor with IC₅₀ value being two orders of magnitude lower than that of the positive control bestatin. Compound 31f possessed selective cytotoxicity to several tumor cell lines over the normal cell line human umbilical vein endothelial cells (HUVECs). Notably, when combined with 5-fluorouracil (5-Fu), 31f exhibited synergistic anti-proliferation effect against several tumor cell lines. At the same concentration, 31f exhibited much better anti-angiogenesis activities than bestatin in the HUVECs capillary tube formation assay and the rat thoracic aorta rings test. In the in vitro anti-invasion assay, 31f also exhibited superior potency over bestatin. Moreover, considerable in vivo antitumor potencies of 31f alone or in combination with 5-Fu were observed without significant toxic signs in a mouse heptoma H22 tumor transplant model.     

Characterization and engineering of the Lrp/AsnC family regulator SACE_5717 for erythromycin overproduction in Saccharopolyspora erythraea

Journal of Industrial Microbiology & Biotechnology - In this work, we found that the Lrp/AsnC family protein SACE_5717 negatively regulated erythromycin biosynthesis in S. erythraea. Disruption...