The regulation of protein uptake and secretion is crucial for (inter)cellular signaling. Mimicking these molecular events is essential when engineering synthetic cellular systems. A first step ...towards achieving this goal is obtaining control over the uptake and release of proteins from synthetic cells in response to an external trigger. Herein, we have developed an artificial cell that sequesters and releases proteinaceous cargo upon addition of a coded chemical signal: single‐stranded DNA oligos (ssDNA) were employed to independently control the localization of a set of three different ssDNA‐modified proteins. The molecular coded signal allows for multiple iterations of triggered uptake and release, regulation of the amount and rate of protein release and the sequential release of the three different proteins. This signaling concept was furthermore used to directionally transfer a protein between two artificial cell populations, providing novel directions for engineering lifelike communication pathways inside higher order (proto)cellular structures.
Proteins can be sequestered and released from artificial cells by attachment of DNA strands and using DNA strand displacement reactions. The DNA elements use a combined regulation mechanism of electrostatic interactions and specific sequence recognition. This provides control over rate of protein release, amount of protein released, and the multiplexity of release.
Non-pathogenic rhizobacteria Pseudomonas spp. can reduce disease in plant tissues through induction of a defence state known as induced systemic resistance (ISR). This resistance is based on multiple ...bacterial determinants, but nothing is known about the mechanisms underlying rhizobacteria-induced resistance in grapevine. In this study, the ability of Pseudomonas fluorescens CHA0 and Pseudomonas aeruginosa 7NSK2 to induce resistance in grapevine against Botrytis cinerea is demonstrated. Both strains also triggered an oxidative burst and phytoalexin (i.e. resveratrol and viniferin) accumulation in grape cells and primed leaves for accelerated phytoalexin production upon challenge with B. cinerea. Treatment of cell cultures with crude cell extracts of bacteria strongly enhanced oxidative burst, but resulted in comparable amounts of phytoalexins and resistance to B. cinerea to those induced by living bacteria. This suggests the production of bacterial compounds serving as inducers of disease resistance. Using other strains with different characteristics, it is shown that P. fluorescens WCS417 (Pch-deficient), P. putida WCS358 (Pch- and SA-deficient) and P. fluorescens Q2-87 (a DAPG producer) were all capable of inducing resistance to an extent similar to that induced by CHA0. However, in response to WCS417 (Pch-negative) the amount of H2O2 induced is less than for the CHA0. WCS417 induced low phytoalexin levels in cells and lost the capacity to prime for phytoalexins in the leaves. This suggests that, depending on the strain, SA, pyochelin, and DAPG are potentially effective in inducing or priming defence responses. The 7NSK2 mutants, KMPCH (Pch- and Pvd-negative) and KMPCH-567 (Pch-, Pvd-, and SA-negative) induced only partial resistance to B. cinerea. However, the amount of H2O2 triggered by KMPCH and KMPCH-567 was similar to that induced by 7NSK2. Both mutants also led to a low level of phytoalexins in grapevine cells, while KMPCH slightly primed grapevine leaves for enhanced phytoalexins. This highlights the importance of SA, pyochelin, and/or pyoverdin in priming phytoalexin responses and induced grapevine resistance by 7NSK2 against B. cinerea.
Exosomes are 40–100nm membrane vesicles secreted into the extracellular space by numerous cell types. These structures can be isolated from body fluids including urine and plasma. Exosomes contain ...proteins, mRNAs, miRNAs, and signaling molecules that reflect the physiological state of their cells of origin and consequently provide a rich source of potential biomarker molecules. Aside from diagnostic uses, exosome-mediated transfer of proteins, mRNAs, miRNAs, and signaling molecules offer the promise that they may be used for therapeutic purposes. In this review, we integrate new knowledge about exosomes from outside the field of nephrology with recent progress by renal researchers in order to provide a basis for speculation about how the study of exosomes may affect the fields of nephrology and renal physiology in the next few years.
Professional antigen‐presenting cells secrete major histocompatibility complex class II (MHC II) carrying exosomes with unclear physiological function(s). Exosomes are first generated as the ...intraluminal vesicles (ILVs) of a specific type of multivesicular body, and are then secreted by fusion of this compartment with the plasma membrane. We have previously shown that in contrast to the sorting of MHC II at lysosomally targeted multivesicular bodies, sorting of MHC II into exosomes does not rely on MHC II ubiquitination. In search for proteins that drive the incorporation of MHC II into exosomes or functionally discriminate exosomal from plasma membrane MHC II, we first analyzed the total proteome of highly purified B cell‐derived exosomes using sensitive and accurate mass spectrometry (MS), and identified 539 proteins, including known and not previously identified constituents. Using quantitative MS, we then identified a small subset of proteins that were specifically co‐immunoprecipitated with MHC II from detergent‐solubilized exosomes. These include HSC71, HSP90, 14‐3‐3ε, CD20 and pyruvate kinase type M2 (PKM2), and we speculate on the functionality of their interaction with exosomal MHC II.
Spontaneous phase separation is a promising strategy for the development of novel electronic materials, as the resulting well‐defined morphologies generally exhibit enhanced conductivity. Making ...these structures adaptive to external stimuli is challenging, yet crucial as multistate reconfigurable switching is essential for neuromorphic materials. Here, a modular and scalable approach is presented to obtain switchable phase‐separated viologen‐siloxane nanostructures with sub‐5 nm features. The domain spacing, morphology, and conductivity of these materials can be tuned by ion exchange, repeated pulsed photoirradiation and electric stimulation. Counterion exchange triggers a postsynthetic modification in domain spacing of up to 10%. Additionally, in some cases, 2D to 1D order–order transitions are observed with the latter exhibiting a sevenfold decrease in conductivity with respect to their 2D lamellar counterparts. Moreover, the combination of the viologen core with tetraphenylborate counterions enables reversible and in situ reduction upon light irradiation. This light‐driven reduction provides access to a continuum of conducting states, reminiscent of long‐term potentiation. The repeated voltage sweeps improve the nanostructures alignment, leading to increased conductivity in a learning effect. Overall, these results highlight the adaptivity of phase‐separated nanostructures for the next generation of organic electronics, with exciting applications in smart sensors and neuromorphic devices.
A scalable approach for tunable properties of viologen‐siloxane block molecules is presented, where the counterion dictates morphology, domain spacing, and conductivity. A light‐responsive counterion is used to reduce the viologen in situ, enhancing its conductivity. The radical cation is stable for several days and can be reversibly oxidized and reduced. Repeated pulsed‐light irradiation results in a continuum of conductive states, exhibiting behavior resemblant to long‐term potentiation.
Benzene is an aromatic compound and harmful for the environment. Biodegradation of benzene can reduce the toxicological risk after accidental or controlled release of this chemical in the ...environment. In this study, we further characterized an anaerobic continuous biofilm culture grown for more than 14 years on benzene with nitrate as electron acceptor. We determined steady state degradation rates, microbial community composition dynamics in the biofilm, and the initial anaerobic benzene degradation reactions. Benzene was degraded at a rate of 0.15 μmol/mg protein/day and a first-order rate constant of 3.04/day which was fourfold higher than rates reported previously. Bacteria belonging to the
Peptococcaceae
were found to play an important role in this anaerobic benzene-degrading biofilm culture, but also members of the
Anaerolineaceae
were predicted to be involved in benzene degradation or benzene metabolite degradation based on Illumina MiSeq analysis of 16S ribosomal RNA genes. Biomass retention in the reactor using a filtration finger resulted in reduction of benzene degradation capacity. Detection of the benzene carboxylase encoding gene,
abcA
, and benzoic acid in the culture vessel indicated that benzene degradation proceeds through an initial carboxylation step.
Purpose
To assess the sustained and acute effects, as well as the influence of sustained consumption on the acute effects, of orange juice (OJ) with a natural hesperidin content and ...hesperidin-enriched OJ (EOJ) on blood (BP) and pulse (PP) pressures in pre- and stage-1 hypertensive individuals.
Methods
In a randomized, parallel, double-blind, placebo-controlled trial, participants (
n
= 159) received 500 mL/day of control drink, OJ, or EOJ for 12 weeks. Two dose–response studies were performed at baseline and after 12 weeks.
Results
A single EOJ dose (500 mL) reduced systolic BP (SBP) and PP, with greater changes after sustained treatment where a decrease in diastolic BP (DBP) also occurred (
P
< 0.05). SBP and PP decreased in a dose-dependent manner relative to the hesperidin content of the beverages throughout the 12 weeks (
P
< 0.05). OJ and EOJ decreased homocysteine levels at 12 weeks versus the control drink (
P
< 0.05). After 12 weeks of EOJ consumption, four genes related to hypertension (PTX3, NLRP3, NPSR1 and NAMPT) were differentially expressed in peripheral blood mononuclear cells (
P
< 0.05).
Conclusion
Hesperidin in OJ reduces SBP and PP after sustained consumption, and after a single dose, the chronic consumption of EOJ enhances its postprandial effect. Decreases in systemic and transcriptomic biomarkers were concomitant with BP and PP changes. EOJ could be a useful co-adjuvant tool for BP and PP management in pre- and stage-1 hypertensive individuals.
Extracellular vesicles (EVs), such as exosomes and microvesicles, are released by different cell types and participate in physiological and pathophysiological processes. EVs mediate intercellular ...communication as cell-derived extracellular signalling organelles that transmit specific information from their cell of origin to their target cells. As a result of these properties, EVs of defined cell types may serve as novel tools for various therapeutic approaches, including (a) anti-tumour therapy, (b) pathogen vaccination, (c) immune-modulatory and regenerative therapies and (d) drug delivery. The translation of EVs into clinical therapies requires the categorization of EV-based therapeutics in compliance with existing regulatory frameworks. As the classification defines subsequent requirements for manufacturing, quality control and clinical investigation, it is of major importance to define whether EVs are considered the active drug components or primarily serve as drug delivery vehicles. For an effective and particularly safe translation of EV-based therapies into clinical practice, a high level of cooperation between researchers, clinicians and competent authorities is essential. In this position statement, basic and clinical scientists, as members of the International Society for Extracellular Vesicles (ISEV) and of the European Cooperation in Science and Technology (COST) program of the European Union, namely European Network on Microvesicles and Exosomes in Health and Disease (ME-HaD), summarize recent developments and the current knowledge of EV-based therapies. Aspects of safety and regulatory requirements that must be considered for pharmaceutical manufacturing and clinical application are highlighted. Production and quality control processes are discussed. Strategies to promote the therapeutic application of EVs in future clinical studies are addressed.
Discrete length block co-oligomers (BCOs) comprised of a crystalline and an amorphous block are a new class of materials that gives highly ordered lamellar morphologies at small length scales. Here, ...we show the preparation of discrete, isotactic oligo l- and d-lactic acid (o lLA and o dLA) homoblocks followed by ligation to oligodimethylsiloxane (oDMS), affording a library of crystalline–amorphous BCOs that vary in molecular weight and composition. Mixing the two enantiomeric BCOs or homoblocks results in the formation of the corresponding stereocomplex. The properties and phase behavior of the isotactic (block co)oligomers and the stereocomplexes thereof are studied using differential scanning calorimetry and small-angle X-ray scattering. A systematic study of the isotactic homoblock lengths and crystal structure confirmed the formation of a 103 helix with a monomeric rise of 0.3 nm, whereas the stereocomplex adopts a 31 helix. The same type of crystal structure was found for the isotactic and stereocomplex of BCOs giving rise to the formation of lamellar morphologies at room temperature as a result of crystallization of the oLA blocks. Distorted lamellar structures were found in BCOs that preorganize into nonlamellar morphologies prior to crystallization. The stereocomplex BCOs shows more crystal defects and a loss of long-range ordering in the microstructure due to the larger driving force for crystallization. Hence, the balance between chain length, block volume, and the crystallization strength are of major importance for the formation of the final structure with the least defects.
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