Saponins are a group of plant glycosides consisting of a steroid or triterpenoid aglycone to which one or more sugar chains are attached. They exhibit cell membrane-permeabilizing properties and, ...thus, have been investigated for their therapeutic potential. Recently, at a non-permeabilizing concentration saponinum album from Gypsophila paniculata L. has been described to enhance the cytotoxicity of a chimeric toxin in a cell culture model. To elucidate whether this enhancing effect is also mediated by other saponins, we analyzed the ability of seven different saponins to enhance the cytotoxicity of a targeted chimeric toxin. The chimeric toxin is composed of saporin, a plant ribosome-inactivating toxin, a cleavable adapter, and human epidermal growth factor (EGF). Cytotoxicity on EGF receptor (EGFR)-bearing cells was analyzed both alone and after combined application of saponin and chimeric toxin. Only two of the tested saponins, quillajasaponin and saponinum album, enhanced cytotoxicity by more than 1,000-fold, whereas the enhancement factors of the other saponins were only approximately 10-fold. In contrast to saponinum album, quillajasaponin enhanced the cytotoxicity both on control cells lacking EGFR and on target cells, indicating that, in this case, the enhancement is not target cell receptor specific. This is also the case for some of the saponins with low enhancement factors. Saponinum album resulted in a more than 13,600-fold receptor-specific enhancement, decreasing the 50% inhibitory concentration (IC(50)) from 2.4 nM to 0.18 pM, which renders it the best option to promote saporin-3-based drug uptake while retaining specificity for the EGFR.
Plant derived saponins or other glycosides are widely used for their anti-inflammatory, antioxidant, and anti-viral properties in therapeutic medicine. In this study, we focus on understanding the ...function of the less known steroidal saponin from the roots of Liriope muscari L. H. Bailey – saponin C (also known as DT-13) in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages in comparison to the well-known saponin ginsenoside Rk1 and anti-inflammatory drug dexamethasone. We proved that DT-13 reduces LPS-induced inflammation by inhibiting nitric oxide (NO) production, interleukin-6 (IL-6) release, cycloxygenase-2 (COX-2), tumour necrosis factor-alpha (TNF-α) gene expression, and nuclear factor kappa-B (NFκB) translocation into the nucleus. It also inhibits the inflammasome component NOD-like receptor family pyrin domain containing protein 3 (NLRP3) regulating the inflammasome activation. This was supported by the significant inhibition of caspase-1 and interleukin-1 beta (IL-1β) expression and release. This study demonstrates the anti-inflammatory effect of saponins on LPS-stimulated macrophages. For the first time, an in vitro study shows the attenuating effect of DT-13 on NLRP3-inflammasome activation. In comparison to the existing anti-inflammatory drug, dexamethasone, and triterpenoid saponin Rk1, DT-13 more efficiently inhibits inflammation in the applied cell culture model. Therefore, DT-13 may serve as a lead compound for the development of new more effective anti-inflammatory drugs with minimised side effects.
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•DT-13 inhibits LPS induced inflammation via NFκB pathway.•DT-13 mediated inhibition of NFκB translocation to nucleus alleviated inflammasome priming by LPS.•Attenuation of inflammasome related genes and caspase-1 implied the role of DT-13 in inflammasome activation.
Cooperative Automated Driving (CAD) brings together driving automation technology with vehicle-to-X (V2X) communication in order to enable vehicles to coordinate their driving maneuvers and achieve a ...common global knowledge of their surroundings, leading to safer and more efficient driving. The IMAGinE research project develops a CAD system based on collective perception and cooperative maneuver coordination and applies it to several use cases where CAD is expected to bring a significant benefit. Furthermore, a connected lane merge function, recently demonstrated as proof-of-concept, shows a first step towards a safe and efficient cooperation among automated vehicles. 5G direct vehicle-to-vehicle communication may enable the implementation of CAD due to its enhanced communication performance.
Membranes are vital barriers by which cells control the flux of molecules and energy between their exterior and interior and also between their various intracellular compartments. While numerous ...transport systems exist for ions and small molecules, the cytosolic uptake of larger biological molecules and in particular antibody-targeted drugs, is a big challenge. Inducing leakage of the plasma membrane is unfavorable since the target cell specificity mediated by the antibody would likely be lost in this case. After binding and internalization, the antibody drug conjugates reach the endosomes. Thus, enforcing the endosomal escape of anti-tumor toxins without affecting the integrity of other cellular membranes is of paramount importance. Different strategies have been developed in the last decades to overcome endosomal accumulation and subsequent lysosomal degradation of targeted protein-based drugs. In this review we summarize the various efforts made to establish efficient techniques to disrupt the endosomal membrane barrier including the use of molecular ferries such as cell penetrating peptides or viral membrane fusion proteins, endosomal leakage inducing molecules such as saponins or monensin and physicochemical methods as represented by photochemical internalization.
Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters-horseradish ...peroxidase (HRP), Alexa Fluor 488 (Alexa) and ricin A-chain (RTA)-were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates-saporin-HRP, (Alexa)saporin and saporin-KQ-RTA-were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release) or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape) was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of (Alexa)saporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10-1000 nM.
The first wintertime in situ measurements of hydroxyl (OH), hydroperoxy (HO2) and organic peroxy (RO2) radicals (ROx=OH+HO2+RO2) in combination with observations of total reactivity of OH radicals, ...kOH in Beijing are presented. The field campaign “Beijing winter finE particle STudy – Oxidation, Nucleation and light Extinctions” (BEST-ONE) was conducted at the suburban site Huairou near Beijing from January to March 2016. It aimed to understand oxidative capacity during wintertime and to elucidate the secondary pollutants' formation mechanism in the North China Plain (NCP). OH radical concentrations at noontime ranged from 2.4×106cm-3 in severely polluted air (kOH∼27s-1) to 3.6×106cm-3 in relatively clean air (kOH∼5s-1). These values are nearly 2-fold larger than OH concentrations observed in previous winter campaigns in Birmingham, Tokyo, and New York City. During this campaign, the total primary production rate of ROx radicals was dominated by the photolysis of nitrous acid accounting for 46 % of the identified primary production pathways for ROx radicals. Other important radical sources were alkene ozonolysis (28 %) and photolysis of oxygenated organic compounds (24 %). A box model was used to simulate the OH, HO2 and RO2 concentrations based on the observations of their long-lived precursors. The model was capable of reproducing the observed diurnal variation of the OH and peroxy radicals during clean days with a factor of 1.5. However, it largely underestimated HO2 andRO2 concentrations by factors up to 5 during pollution episodes. The HO2 and RO2 observed-to-modeled ratios increased with increasing NO concentrations, indicating a deficit in our understanding of the gas-phase chemistry in the high NOx regime. The OH concentrations observed in the presence of large OH reactivities indicate that atmospheric trace gas oxidation by photochemical processes can be highly effective even during wintertime, thereby facilitating the vigorous formation of secondary pollutants.
At the atmosphere simulation chamber SAPHIR in Jülich both Laser-Induced Fluorescence Spectroscopy (LIF) and Long-Path Differential Optical Laser Absorption Spectroscopy (DOAS) are operational for ...the detection of OH radicals at tropospheric levels. The two different spectroscopic techniques were compared within the controlled environment of SAPHIR based on all simultaneous measurements acquired in 2003 (13 days). Hydroxyl radicals were scavenged by added CO during four of these days in order to experimentally check the calculated precisions at the detection limit. LIF measurements have a higher precision (σ= 0.88×10^sup 6^ cm^sup -3^) and better time resolution (Δt = 60 s), but the DOAS method (σ= 1.24×10^sup 6^ cm^sup -3^, Δt = 135 s) is regarded as primary standard for comparisons because of its good accuracy. A high correlation coefficient of r = 0.95 was found for the whole data set highlighting the advantage of using a simulation chamber. The data set consists of two groups. The first one includes 3 days, where the LIF measurements yield (1 - 2) ×10^sup 6^ cm^sup -3^ higher OH concentrations than observed by the DOAS instrument. The experimental conditions during these days are characterized by increased NO^sub x^ concentration and a small dynamic range in OH. Excellent agreement is found within the other group of 6 days. The regression to the combined data of this large group yields unity slope without a significant offset.PUBLICATION ABSTRACT
A comprehensive field campaign was carried out in summer 2014 in Wangdu, located in the North China Plain. A month of continuous OH, HO2 and RO2 measurements was achieved. Observations of radicals by ...the laser-induced fluorescence (LIF) technique revealed daily maximum concentrations between (5-15) × 106cm-3, (3-14) × 108cm-3 and (3-15) × 108cm-3 for OH, HO2 and RO2, respectively. Measured OH reactivities (inverse OH lifetime) were 10 to 20s-1 during daytime. The chemical box model RACM 2, including the Leuven isoprene mechanism (LIM), was used to interpret the observed radical concentrations. As in previous field campaigns in China, modeled and measured OH concentrations agree for NO mixing ratios higher than 1ppbv, but systematic discrepancies are observed in the afternoon for NO mixing ratios of less than 300pptv (the model-measurement ratio is between 1.4 and 2 in this case). If additional OH recycling equivalent to 100pptv NO is assumed, the model is capable of reproducing the observed OH, HO2 and RO2 concentrations for conditions of high volatile organic compound (VOC) and low NOx concentrations. For HO2, good agreement is found between modeled and observed concentrations during day and night. In the case of RO2, the agreement between model calculations and measurements is good in the late afternoon when NO concentrations are below 0.3ppbv. A significant model underprediction of RO2 by a factor of 3 to 5 is found in the morning at NO concentrations higher than 1ppbv, which can be explained by a missing RO2 source of 2ppbv h-1. As a consequence, the model underpredicts the photochemical net ozone production by 20ppbv per day, which is a significant portion of the daily integrated ozone production (110ppbv) derived from the measured HO2 and RO2. The additional RO2 production from the photolysis of ClNO2 and missing reactivity can explain about 10% and 20% of the discrepancy, respectively. The underprediction of the photochemical ozone production at high NOx found in this study is consistent with the results from other field campaigns in urban environments, which underlines the need for better understanding of the peroxy radical chemistry for high NOx conditions.
To report the first clinical implantation of a foldable, spherical multiple component intraocular lens (MC-IOL). Previous studies and publications described a polymethylmethacrylate version of this ...lens, which required a 7-mm incision for its implantation. The foldable version of this lens system can be inserted through a < 3-mm incision.
Following routine cataract surgery, the base lens component of the MC-IOL was inserted with a 2.8-mm injector into the capsular bag of a 62-year-old woman. The front lens assembly of the spherical MC-IOL was injected into the anterior chamber. The haptics of the front lens were then inserted into the capture bridges of the base lens completing the lens assembly procedure. The remainder of the cataract procedure was performed routinely.
Six-week follow-up showed 20/20 corrected vision with a refraction of +1.00 +0.25 x 106 degrees. The MC-IOL was centrally located in the capsule, and good clearance was noted between the lens and iris.
The foldable version of the MC-IOL can be inserted through a conventional small cataract incision (< 3 mm). In this patient, the lens was well tolerated and generated the expected 20/20 visual acuity. The first MC-IOL prototype had only spherical components and the surgery was performed to demonstrate the feasibility of doing such an operation, assembling and disassembling the optical elements of the MC-IOL in the eye. The surgeon was able to perform these manipulations with a short learning curve and standard cataract instrumentation.
Photolysis of oxygenated volatile organic compounds (OVOCs) produces a primary source of free radicals, including OH and inorganic and organic peroxy radicals (HO2 and RO2), consequently increasing ...photochemical ozone production. The amplification of radical cycling through OVOC photolysis provides an important positive feedback mechanism to accelerate ozone production. The large production of OVOCs near the surface helps promote photochemistry in the whole boundary layer. This amplifier effect is most significant in regions with high nitrogen oxides (NO x ) and VOC concentrations such as Wangdu, China. Using a 1-D model with comprehensive observations at Wangdu and the Master Chemical Mechanism (MCM), we find that OVOC photolysis is the largest free-radical source in the boundary layer (46%). The condensed chemistry mechanism we used severely underestimates the OVOC amplifier effect in the boundary layer, resulting in a lower ozone production rate sensitivity to NO x emissions. Due to this underestimation, the model-simulated threshold NO x emission value, below which ozone production decreases with NO x emission decrease, is biased low by 24%. The underestimated OVOC amplifier effect in a condensed mechanism implies a low bias in the current 3-D model-estimated efficacy of NO x emission reduction on controlling ozone in polluted urban and suburban regions of China.
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