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Primary hyperoxaluria type I is caused by mutations in the alanine glyoxylate aminotransferase gene (AGXT), leading to accumulation of glyoxylate and subsequent production of oxalate and urolithiasis. Here, we generated a novel rat model of primary hyperoxaluria type I that carries a D205N mutation in the partially humanized Agxt gene through the CRISPR/Cas9 system. The AgxtD205N mutant rats showed undetectable alanine glyoxylate aminotransferase protein expression, developed hyperoxaluria at 1 month of age and exhibited severe renal calcium oxalate deposition after ethylene glycol challenge. This suggests our novel model is more relevant to the human disease than existing animal models. To test whether this model could be used for the development of innovative therapeutics, SaCas9 targeting hydroxyacid oxidase 1, responsible for metabolizing glycolate into glyoxylate, was delivered via adeno-associated viral vectors into newborn rats with primary hyperoxaluria type 1. This approach generated nearly 30% indels in the Hao1 gene in the liver, leading to 42% lower urine oxalate levels in the treated group than in the control group and preventing the rats with primary hyperoxaluria type 1 from undergoing severe nephrocalcinosis for at least 12 months. Thus, our results demonstrate that this partially humanized AgxtD205N rat strain is a high-performing model of primary hyperoxaluria type 1 for understanding pathology, and the development of novel therapeutics, such as reprogramming of the metabolic pathway through genome editing., (Copyright © 2020 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Electroactive bacteria could perform bi-directional extracellular electron transfer (EET) to exchange electrons and energy with extracellular environments, thus playing a central role in microbial electro-fermentation (EF) process. Unbalanced fermentation and microbial electrosynthesis are the main pathways to produce value-added chemicals and biofuels. However, the low efficiency of the bi-directional EET is a dominating bottleneck in these processes. In this review, we firstly demonstrate the main bi-directional EET mechanisms during EF, including the direct EET and the shuttle-mediated EET. Then, we review representative milestones and progresses in unbalanced fermentation via anode outward EET and microbial electrosynthesis via inward EET based on these two EET mechanisms in detail. Furthermore, we summarize the main synthetic biology strategies in improving the bi-directional EET and target products synthesis, thus to enhance the efficiencies in unbalanced fermentation and microbial electrosynthesis. Lastly, a perspective on the applications of microbial electro-fermentation is provided., (© 2020 KeAi Communications Co.(+) Ltd.)

Impaired neuronal differentiation is a feature of neuroblastoma tumorigenesis, and the differentiation grade of neuroblastoma tumors is associated with patient prognosis. Detailed understanding of the molecular mechanisms underlying neuroblastoma differentiation will facilitate the development of effective treatment strategies. Recent studies have shown that myelin transcription factor 1 (MYT1) promotes vertebrate neurogenesis by regulating gene expression. We performed quantitative analysis of neuroblastoma samples, which revealed that MYT1 was differentially expressed among neuroblastoma patients with different pathological diagnoses. Analysis of clinical data showed that MYT1 overexpression was associated with a significantly shorter 3-year overall survival rate and poor differentiation in neuroblastoma specimens. MYT1 knockdown inhibited proliferation and promoted the expression of multiple differentiation-associated proteins. Integrated omics data indicated that many genes involved in neuro-differentiation were regulated by MYT1. Interestingly, many of these genes are targets of the REST complex; therefore, we further identified the physical interaction of MYT1 with LSD1/CoREST. Depletion of LSD1 or inhibition of LSD1 by ORY-1001 decreased MYT1 expression, providing an alternative approach to target MYT1. Taken together, our results indicate that MYT1 significantly attenuates cell differentiation by interacting with the LSD1/CoREST complex. MYT1 is, therefore, a promising therapeutic target for enhancing the neurite-inducing effect of retinoic acid and for inhibiting the growth of neuroblastoma.

An electroreductive 4-pyridylation of activated alkenes was developed in an undivided cell with the assistance of Ni(acac) 2 (acac = acetylacetone). This novel protocol is compatible with a broad range of electron-poor alkenes, which are commonly regarded as challenging substrates in the previous conventional approaches. Moreover, a series of cyclic voltammetric experiments were conducted to reveal the unique role of Ni(acac) 2 differentiating reduction process of reaction partners.

Despite the unceasing flourishing of intelligent actuators, it still remains a huge challenge to design mechanically robust soft actuators with the characteristics of three-dimensional (3D) programmability, reconfigurability, and recyclability. Here, we utilize fully bioderived natural polymers to fabricate biomass soft actuators (BioSA) integrating all above features through an ingenious microstructure design. BioSA consists of an interconnected inverse opal-mimetic skeleton of sodium alginate (NaAlg) and a continuous matrix of epoxidized natural rubber (ENR), with exchangeable β-hydroxyl ester linkages at their interfaces. The hydrophilic nature and interconnected structure of the NaAlg skeleton endow BioSA with exceedingly acute humidity response and robust mechanical properties. Meanwhile, the dynamic nature of β-hydroxyl ester linkages enables the design of complex 3D structured soft actuators with reconfigurability and recyclability. Since both ENR and NaAlg are derived from natural resources, and the water-based manufacturing process is extremely facile and environmentally friendly, this work provides a novel strategy to fabricate 3D programmable intelligent actuators with both robust mechanical properties and sustainability.

T cell homeostasis is critical for the proper function of the immune system. Following the sharp expansion upon pathogen infection, most T cells die in order to keep balance in the immune system, a process which is controlled by death receptors during the early phase and Bcl-2 proteins in the later phase. It is still highly debated whether the apoptosis of T cells is determined from the beginning, upon activation, or determined later during the contraction. MCL1, a Bcl-2 family member, plays a pivotal role in T cell survival. As a fast turnover protein, MCL1 levels are tightly regulated by the 26S proteasome-controlled protein degradation process. In searching for regulatory factors involved in the actions of MCL1 during T cell apoptosis, we found that ALG-2 was critical for MCL1 stability, a process mediated by a direct interaction between ALG-2 and Rpn3, a key component of the 26S proteasome. As a critical calcium sensor, ALG-2 regulated the activity of the 26S proteasome upon increases to cytosolic calcium levels following T cell activation, this consequently influenced the stability of MCL1 and accelerated the T cell "death" process, leading to T cell contraction and restoration of immune homeostasis. Our study provides support for the notion that T cells are destined for apoptosis after activation, and echoes the previous study about the function of ALG-2 in T cell death.

Particle swarm optimizer (PSO) is a population-based optimization technique applied to a wide range of problems. In the literature, many PSO variants have been proposed to deal with noise-free or noisy environments, respectively. While in real-life applications, noise emerges irregularly and unpredictably. As a result, PSO for a noise-free environment loses its accuracy when noise exists, while PSO for a noisy environment wastes its resampling resource when noise does not exist. To handle such scenario, a PSO variant that can work well in both noise-free and noisy environments is required, which does, to the authors' best knowledge, not exist yet. To fill such gap, this work proposes a novel PSO variant named as dual-environmental PSO (DEPSO). It uses a weighted search center based on top- k elite particles to guide the swarm. It averages their positions rather than resampling fitness values of particles to achieve noise reduction, which challenges the indispensable role of the resampling method in a noisy environment and adapts to a noise-free environment as well. Two theoretical analyses are presented for noise reduction and finer local optimization capabilities. Experimental results performed on CEC2013 benchmark functions indicate that DEPSO outperforms state-of-the-art PSO variants in both noise-free and noisy environments.

Purpose: As well as functioning as a ligand that is selectively internalized by cells overexpressing human epidermal growth factor receptor-2 (HER2), HApt can exert cytotoxic effects by inducing cross-linking and subsequent translocation of HER2 to cytoplasmic vesicles, such downregulation of HER2 inhibits cell proliferation and induces apoptosis. We aimed to exploit the potential of HApt as both a targeting agent and antagonist to maximize the efficacy of mesoporous silica nanoparticle (MSN)-based drug release systems for HER2-positive breast cancer. Materials and methods: We fabricated novel HApt aptamer-functionalized pH-sensitive β-cyclodextrin (β-CD)-capped doxorubicin (DOX)-loaded mesoporous silica nanoparticles (termed MSN-BM/CD-HApt@DOX) for targeted delivery and selective targeting of HER2-positive cells. MSN-functionalized benzimidazole (MSN-BM) was used to load and achieve pH stimuli-responsive release of the chemotherapeutic agent doxorubicin (DOX). β-cyclodextrin was introduced as a gatekeeper for encapsulated DOX and HApt as a selective HER2-targeting moiety and biotherapeutic agent. Results: Physical and chemical characterizations (FT-IR, XRD, TEM and BET) confirmed successful construction of MSN-BM/CD-HApt@DOX nanoparticles. In vitro release assays verified pH-sensitive DOX release. MSN-BM/CD-HApt@DOX (relative DOX concentration, 3.6 μg/mL) underwent HER2-mediated endocytosis and was more cytotoxic to HER2-positive SKBR3 cells than HER2-negative MCF7 cells. MSN-BM/CD-HApt@DOX also exhibited better uptake and stronger growth inhibition in SKBR3 cells than the control MSN-BM/CD-NCApt@DOX functionalized with a scrambled nucleotide sequence on CD. Overall, intracellular delivery of DOX and the biotherapeutic agent HApt resulted in synergistic cytotoxic effects in HER2-positive cancer cells in comparison to either DOX or HApt alone. Conclusion: MSN-BM/CD-HApt@DOX enables HER2-mediated targeting and biotherapeutic effects as well as pH-responsive DOX drug release, resulting in synergistic cytotoxic effects in HER2-overexpressing cells in vitro. This novel nanocarrier could potentially enable specific targeting to improve the efficacy of chemotherapy for HER2-positive cancer., Competing Interests: The authors report no conflicts of interest in this work.

Gold-catalyzed oxidations of alkynes by N-oxides offer direct access to reactive α-oxo gold carbene intermediates from benign and readily available alkynes instead of hazardous diazo carbonyl compounds. Despite various versatile synthetic methods developed based on this strategy, one of the hallmarks of α-oxo carbene/carbenoid chemistry, that is, the Wolff rearrangement, has not been realized in this context. This study discloses the first examples that show the Wolff rearrangement can be readily realized by α-oxo gold carbenes oxidatively generated from TBS-terminated alkynes (TBS=tert-butyldimethylsilyl). The thus-generated silylketenes can be either isolated pure or subsequently trapped by various internal or external nucleophiles in one pot to afford α-silylated carboxylic acids, their derivatives, or TBS-substituted allenes., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An electrochemical difluoromethylation triggered lactonization of alkenes was developed for the first time. This protocol employs readily prepared CF 2 HSO 2 Na as the difluoromethylating reagent, affording unprecedented CF 2 H-containing lactones in moderate yields. Moreover, with CF 3 SO 2 Na as the trifluoromethylating reagent, a wide array of CF 3 -containing lactones were obtained under additional supporting electrolyte- and catalyst-free conditions.

Antitumor peptides may potentially alleviate the problem of chemoresistance but do not yet target tumor cells and would be cytotoxic to normal cells. Here, we designed a pH-activated and thermosensitive lipopeptide (C6-Pep) containing a leucine zipper and an alkyl chain and assessed the ability of C6-Pep to kill cancer cells. Pep, the same sequence without the N-terminal hexanoic acid moiety, was generated as a less hydrophobic control. First, lipopeptide adsorption into lipid monolayers was studied using Langmuir-Blodgett and polarization modulation infrared reflection adsorption spectroscopy. Under weakly acid conditions, electrostatic interactions between C6-Pep and negatively charged phospholipids increased the adsorption/insertion of C6-Pep (vs Pep) into lipid monolayers. Cargo leakage from liposomes was assayed to model lipopeptide-induced lipid membrane disruption. The ability of C6-Pep to disrupt liposomes depended on the peptide molecular structure/hydrophobicity, solution pH, and temperature-induced uncoiling of the zipper structure; the greatest cargo leakage from the liposome with negative charge was observed for C6-Pep at pH 5.5 under mildly hyperthermic conditions (45 °C). In vitro, C6-Pep was significantly more cytotoxic toward HeLa cells at pH 5.5 under hyperthermic conditions than at pH 7.4 and/or 37 °C. Overall, this study demonstrates that amphipathic C6-Pep can insert into cell membranes in the low-pH tumor microenvironment, whereas the application of heat promotes the uncoiling of the zipper structure, leading to the disruption of tumor cell membranes and cell death. pH-activated and thermosensitive C6-Pep represents a promising tool to kill cancer cells via a strategy that does not invoke chemoresistance and may have low side effects.

An epoxy-phenolic network is modified with hyperbranched polysiloxane (HBPSi). The addition of HBPSi-2, which has medium molecular weight, can significantly decrease the viscosity of the uncured epoxy-phenolic system and increase the crosslinking density and homogeneity of the cured crosslinking network. With 10% HBPSi-2, the mechanical properties of the samples are improved comprehensively: tensile modulus and maximum strength increase by 11.4% and 36.2%, respectively, while elongation at break and impact strength increase by 153.8% and 186.7%, respectively. The comprehensive improvements in the mechanical properties are attributed to combined effects of crosslinking density, network rigidity, cohesive density and the matrix-modifier compatibility. What is more, HBPSi-2 also significantly increases the char yield of the material and decreases the thermal weight loss rate, indicating an improved thermal stability. All these results may provide a new strategy for toughness and strength improvement of the epoxy-phenolic network., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Discovering and tracking spatiotemporal event patterns have many applications. For example, in a smart-home project, a set of spatiotemporal pattern learning automata are used to monitor a user's repetitive activities, by which the home's automaticity can be promoted while some of his/her burdens can be reduced. Existing algorithms for spatiotemporal event pattern recognition in dynamic noisy environment are based on fixed structure stochastic automata whose state transition function is fixed and predesigned to guarantee their immunity to noise. However, such design is conservative because it needs continuous and identical feedbacks to converge, thus leading to its very low convergence rate. In many real-life applications, such as ambient assisted living, consecutive nonoccurrences of an elder resident's routine activities should be treated with an alert as quickly as possible. On the other hand, no alert should be output even for some occurrences in order to diminish the effects caused by noise. Clearly, confronting a pattern's change, slow speed and low accuracy may degrade a user's life security. This paper proposes a fast and accurate leaning automaton based on variable structure stochastic automata to satisfy the realistic requirements for both speed and accuracy. Bias toward alert is necessary for elder residents while the existing method can only support the bias toward "no alert." This paper introduces a method to allow bias toward alert or no alert to meet a user's specific bias requirement. Experimental results show its better performance than the state-of-the-art methods.

Efficient delivery of nucleic acids into target cells is crucial for nucleic acid-based therapies. Various nucleic acid delivery systems have been developed, each with its own advantages and limitations. We previously developed a nanoparticle-based delivery system for small chemical drugs using pH-responsive PEG 8 -PDPA 100 -PEG 8 polymer micelles as carriers. In this study, we extend the application of these pH-responsive micelle-like nanoparticles (MNPs) to deliver oligonucleotides. We demonstrate that the MNPs efficiently encapsulate and deliver oligonucleotides of different lengths (20-100 nt) into cells. The cargo oligonucleotides are rapidly released at pH 5.0. We prepared MNPs carrying a Texas red-fluorescently labeled anti-human epidermal growth factor receptor 2 (HER2) aptamer (HApt). Compared to free HApt, the HApt-MNPs resulted in significantly better cellular uptake, reduced cell viability, and increased apoptosis in SKBR3 breast cancer cells, which overexpress HER2. Moreover, HApt-MNPs were significantly less cytotoxic to MCF7 breast cancer cells, which express low levels of HER2. After cellular uptake, HApt-MNPs mainly accumulated in lysosomes; inhibition of lysosomal activity using bafilomycin A1 and LysoTracker Red staining confirmed that lysosomal activity and low pH were required for HApt-MNP accumulation and release. Furthermore, HER2 protein expression declined significantly following treatment with HApt-MNPs in SKBR3 cells, indicating that HApt-induced translocation of HER2 to lysosomes exerted a potent cytotoxic effect by altering signaling downstream of HER2. In conclusion, this pH-responsive and lysosome-targeting nanoparticle system can efficiently deliver oligonucleotides to specific target cells and has significant potential for nucleic acid-based cancer therapies., Competing Interests: Disclosure The authors report no conflicts of interest in this work.

Hepatitis B virus (HBV) generally causes self-limiting infection in immunocompetent adults, but establishes chronic infection in some adults and in most maternally infected infants. Factors determining clearance versus persistence are not fully understood. Hydrodynamic injection (HDI) of HBV replicon plasmid via tail vein generally results in quick clearance in immunocompetent adult mice. Here, we report the identification of strain-specific persistence of HBV in mice: one genotype B strain, designated BPS, persisted up to 33 weeks in ~50% of HDI mice. BPS persistence requires viral replication and multiple viral features. Compared to quickly cleared strains, BPS fails to induce robust post-exposure serum IL-21/IL-33 responses. Injection of IL-21-expressing or IL-33-expressing plasmids facilitates clearance of pre-established BPS persistence and protects cured mice from BPS re-challenge. IL-21 and IL-33 also induce clearance of pre-established HBV persistence in another mouse model. These data reveal IL-21 and IL-33 as potent regulators of HBV clearance and valid drug candidates.

White light interference is used as a label-free method to detect nanoscale changes on surfaces. However, the signal-to-noise ratio of the white light interference method is very low, thus resulting in inaccurate results. In this paper, we report a corrected label-free method based on hyperspectral interferometry to overcome the shortcoming of the white light interference method. A platform based on hyperspectral interferometry was established, and a DNA hybridization microarray was constructed to quantitate thickness variation of molecules on a solid surface. We used fluorescence resonance energy transfer (FRET) to validate the results of our method. Compared to conventional fluorescence-labeled method like FRET, our method has advantages because it does not require a fluorescent label and has a detection limit of 1.78 nm, a high accuracy, and wide detection range (5-64 bp).

There has been increasing interest in the construction of liposomes containing a targeting reagent for target-specific drug delivery. Glycoconjugates that can be recognized by transmembrane glycoprotein receptors have been extensively used to form glyco-liposomal drug carriers. However, the impact of anomerism, which is a common identity of natural glycoconjugates, on the glyco-liposomal properties has been hardly probed in previous studies. Here we investigate the liposomal properties of phospholipid incorporated with a pair of anomeric galactolipids. The anomeric galacto-liposomes are characterized and their membrane fluidity, thermo-stability, DNA condensation efficiency and fluorescence leakage are comparatively tested. The in vitro cellular internalization effect of the galacto-liposomes is also demonstrated. This study suggests that anomerism might give distinct impact on the membrane properties and even biofunctions of glyco-liposomes.

Hepatitis B virus (HBV) takes humans as its sole natural host, and productive infection in vivo is restricted exclusively to hepatocytes in the liver. Consequently, HBV-derived viral vectors are attractive candidates for liver-targeting gene therapies. Previously, we developed a novel recombinant HBV vector, designated 5c3c, from a highly replicative clinical isolate. 5c3c was demonstrated to be capable of efficiently delivering protein or RNA expression into infected primary tupaia hepatocytes (PTH), but the design of 5c3c imposes stringent restrictions on inserted sequences, which have limited its wider adoption. In this work, we addressed issues with 5c3c by re-designing the insertion strategy. The resultant vector, designated 5dCG, was more replicative than parental 5c3c, imposed no specific restrictions on inserted sequences, and allowed insertion of a variety of cargo genes without significant loss of replication efficiency. 5dCG-based recombinant HBV effectively delivered protein and RNA expression into infected PTH. Furthermore, due to the loss of functional core ORF, 5dCG vectors depend on co-infecting wild type HBV for replication and efficient expression of cargo genes. Development of the improved 5dCG vector makes wider applications of recombinant HBV possible, while dependence on co-infecting wild type HBV results in improved safety for certain in vivo applications.

Accumulating evidence suggests that the nucleus accumbens, which is involved in mechanisms of reward and addiction, plays a role in the pathogenesis of depression and in the action of antidepressants. In the current study, intraperitoneal injection of nomifensine, a dopamine reuptake inhibitor, decreased depression-like behaviors in the Wistar Kyoto rat model of depression in the sucrose-preference and forced swim tests. Nomifensine also reduced membrane excitability in medium spiny neurons in the core of the nucleus accumbens in the childhood Wistar Kyoto rats as evaluated by electrophysiological recording. In addition, the expression of dopamine D2-like receptor mRNA was downregulated in the nucleus accumbens, striatum and hippocampus of nomifensine-treated childhood Wistar Kyoto rats. These experimental findings indicate that impaired inhibition of medium spiny neurons, mediated by dopamine D2-like receptors, may be involved in the formation of depression-like behavior in childhood Wistar Kyoto rats, and that nomifensine can alleviate depressive behaviors by reducing medium spiny neuron membrane excitability.

Background: Shigella is a major pathogen responsible for bacillary dysentery, a severe form of shigellosis. Severity of the disease depends on the virulence of the infecting strain. Shigella pathogenicity is a multi-gene phenomenon, involving the participation of genes on an unstable large virulence plasmid and chromosomal pathogenicity islands., Results: A multiplex PCR (mPCR) assay was developed to detect S. flexneri 2a from rural regions of Zhengding (Hebei Province, China). We isolated and tested 86 strains using our mPCR assay, which targeted the ipaH, ial and set1B genes. A clinical strain of S. flexneri 2a 51 (SF51) containing ipaH and ial, but lacking set1B was found. The virulence of this strain was found to be markedly decreased. Further testing showed that the SF51 strain lacked pic. To investigate the role of pic in S. flexneri 2a infections, a pic knockout mutant (SF301-∆ pic) and two complementation strains, SF301-∆ pic/pPic and SF51/pPic, were created. Differences in virulence for SF51, SF301-∆ pic, SF301-∆ pic/pPic, SF51/pPic and S. flexneri 2a 301 (SF301) were compared. Compared with SF301, both SF51 and SF301-∆ pic exhibited lower levels of Hela cell invasion and resulted in reduced keratoconjunctivitis, with low levels of tissue damage seen in murine eye sections. The virulence of SF301-∆ pic and SF51 was partially recovered in vitro and in vivo through the addition of a complementary pic gene., Conclusions: The pic gene appears to be involved in an increase in pathogenicity of S. flexneri 2a. This gene assists with bacterial invasion into host cells and alters inflammatory reactions.

This paper is composed with the cardiac sound measurement and analysis system for in-home use of heart abnormality monitoring. The heart sound acquiring system is composed of a traditional chest-piece, earphone, microphone, and IC recorder. The recorded data is transmitted to a computer by USB interface for analysis based on the cardiac sound characteristic waveform (CSCW) method, which is extracted from an analytical model of single degree-of-freedom (SDOF). Furthermore, the characteristic parameters [T1, T2, T11, T12] are defined by the time intervals between the crossed points of the CSCW and a threshold value (THV), which are related to the first sound and the second sound and are used for discriminating normal and abnormal heart sounds. Also, an easy-understanding graphical representation for these parameters is considered, so that, even for an inexperienced user, he or she is able to monitor his or her cardiac status easily. Finally, a case study on the abnormal/normal cardiac sounds is demonstrated to validate the usefulness and efficiency of this proposed system and the cardiac sound characteristic waveform method.