Reversing Anticancer Drug Resistance by Synergistic Combination of Chemotherapeutics and Membranolytic Antitumor β-Peptide Polymer

Multidrug resistance is the main obstacle to cancer chemotherapy. Overexpression of drug efflux pumps causes excessive drug efflux from cancer cells, ultimately leading to drug resistance. Hereby, we raise an effective strategy to overcome multidrug resistance using a synergistic combination of membranolytic antitumor β-peptide polymer and chemotherapy drugs. This membrane-active β-peptide polymer promotes the transmembrane transport of chemotherapeutic drugs by increasing membrane permeability and enhances the activity of chemotherapy drugs against multidrug-resistant cancer cells. As a proof-of-concept demonstration, the synergistic combination of β-peptide polymer and doxorubicin (DOX) is substantially more effective than DOX alone against drug-resistant cancer both in vitro and in vivo. Notably, the synergistic combination maintains a potent anticancer activity after continuous use. Collectively, this combination therapy using membrane lytic β-peptide polymer appears to be an effective strategy to reverse anticancer drug resistance.

A dual-targeting antifungal is effective against multidrug-resistant human fungal pathogens

Drug-resistant fungal infections pose a significant threat to human health. Dual-targeting compounds, which have multiple targets on a single pathogen, offer an effective approach to combat drug-resistant pathogens, although ensuring potent activity and high selectivity remains a challenge. Here we propose a dual-targeting strategy for designing antifungal compounds. We incorporate DNA-binding naphthalene groups as the hydrophobic moieties into the host defence peptide-mimicking poly(2-oxazoline)s. This resulted in a compound, (Gly0.8Nap0.2)20, which targets both the fungal membrane and DNA. This compound kills clinical strains of multidrug-resistant fungi including Candida spp., Cryptococcus neoformans, Cryptococcus gattii and Aspergillus fumigatus. (Gly0.8Nap0.2)20 shows superior performance compared with amphotericin B by showing not only potent antifungal activities but also high antifungal selectivity. The compound also does not induce antimicrobial resistance. Moreover, (Gly0.8Nap0.2)20 exhibits promising in vivo therapeutic activities against drug-resistant Candida albicans in mouse models of skin abrasion, corneal infection and systemic infection. This study shows that dual-targeting antifungal compounds may be effective in combating drug-resistant fungal pathogens and mitigating fungal resistance.

Modeling critical interaction for metastasis between circulating tumor cells (CTCs) and platelets adhered to the capillary wall

BACKGROUND AND OBJECTIVE

We used a 2D fluid-solid interaction (FSI) model to investigate the critical conditions for the arrest of the CTCs traveling through the narrowed capillary with a platelet attached to the capillary wall. This computational model allows us to determine the deformations and the progression of the passage of the CTC through different types of microvessels with platelet included.

METHODS

The modeling process is obtained using the strong coupling approach following the remeshing procedure. Also, the 1D FE rope element for simulating active ligand-receptor bonds is implemented in our computational tool (described below).

RESULTS

A relationship between the CTCs properties (size and stiffness), the platelet size and stiffness, and the ligand-receptor interaction intensity, on one side, and the time in contact between the CTCs and platelet and conditions for the cell arrest, on the other side, are determined. The model is further validated in vitro by using a microfluidic device with metastatic breast tumor cells.

CONCLUSIONS

The computational framework that is presented, with accompanying results, can be used as a powerful tool to study biomechanical conditions for CTCs arrest in interaction with platelets, giving a prognosis of disease progression.

Convenient and Controllable Synthesis of Poly(2-oxazoline)-Conjugated Doxorubicin for Regulating Anti-Tumor Selectivity

Polyethylene glycol (PEG)-doxorubicin (DOX) conjugation is an important strategy to improve toxicity and enhance clinically therapeutic efficacy. However, with the frequent use of PEG-modified drugs, the accumulation of anti-PEG antibodies has become a tough issue, which limits the application of PEG-drug conjugation. As an alternative solution, poly(2-oxazoline) (POX)-DOX conjugation has shown great potential in the anti-tumor field, but the reported conjugation process of POX with DOX has drawbacks such as complex synthetic steps and purification. Herein, we propose a convenient and controllable strategy for the synthesis of POX-DOX conjugation with different chain lengths and narrow dispersity by N-boc-2-bromoacetohydrazide-initiated 2-ethyl-oxazoline polymerization and the subsequent deprotection of the N-Boc group and direct reaction with DOX. The DOX-PEtOx conjugates were firstly purified, and the successful conjugations were confirmed through various characterization methods. The synthetic DOX-PEtOx_n conjugates reduce the toxicity of DOX and increase the selectivity to tumor cells, reflecting the promising application of this POX-DOX conjugation strategy in drug modification and development.

Rapid and Accurate Detection of SARS-CoV-2 Using an iPad-Controlled, High-Throughput, Portable, and Multiplex Hive-Chip Platform (HiCube)

Rapid and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the most effective measures to control the coronavirus disease 2019 (COVID-19) pandemic. However, there is still lack of an ideal detection platform capable of high sample throughput, portability, and multiplicity. Herein, by combining Hive-Chip (capillary microarray) and reverse transcriptional loop-mediated isothermal amplification (RT-LAMP), we developed an iPad-controlled, high-throughput (48 samples at one run), portable (smaller than a backpack), multiplex (monitoring 8 gene fragments in one reaction), and real-time detection platform for SARS-CoV-2 detection. This platform is composed of a portable Hive-Chip device (HiCube; 32.7 × 29.7 × 20 cm, 5 kg), custom-designed software, and optimized Hive-Chips. RT-LAMP primers targeting seven SARS-CoV-2 genes (S, E, M, N, ORF1ab, ORF3a, and ORF7a) and one positive control (human RNase P) were designed and prefixed in the Hive-Chip. On-chip RT-LAMP showed that the limit of detection (LOD) of SARS-CoV-2 synthetic RNAs is 1 copy/μL, and there is no cross-reaction among different target genes. The platform was validated by 100 clinical samples of SARS-CoV-2, and the results were highly consistent with those of the traditional real-time PCR assay. In addition, on-chip detection of 6 other respiratory pathogens showed no cross-reactivity. Overall, our platform has great potential for fast, accurate, and on-site detection of SARS-CoV-2.

A Bidirectional Single-Cell Migration and Retrieval Chip for Quantitative Study of Dendritic Cell Migration

Dendritic cell (DC) migration is a fundamental step during execution of its adaptive immunity functions. Studying DC migration characteristics is critical for development of DC-dependent allergy treatments, vaccines, and cancer immunotherapies. Here, a microfluidics-based single-cell migration platform is described that enables high-throughput and precise bidirectional cell migration assays. It also allows selective retrieval of cell subpopulations that have different migratory potentials. Using this microfluidic platform, DC migration is investigated in response to different chemoattractants and inhibitors, quantitatively describe DC migration patterns and retrieve DC subpopulations of different migratory potentials for differential gene expression analysis. This platform opens an avenue for precise characterization of cell migration and potential discovery of therapeutic modulators.

Development and validation of a novel immunotype for prediction of overall survival in patients with clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a highly immunogenic tumor. The purpose of the present study was to establish a novel immunotype for different immune infiltration and overall survival (OS) of patients with ccRCC.

Methods

Based on the Cancer Genome Atlas Project (TCGA) database (discovery set), a novel immunotype was established using ssGSEA methods. The databases of Fudan University Shanghai Cancer Center (FUSCC) and Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine (XHH) served as an external validation set. GSEA was carried out to identify the immunotype associated signal transduction pathways.

Results

A total of 652 ccRCC patients were included in our study. We constructed a novel immunotype of ccRCC to classify patients into three groups: high-immunity, moderate-immunity, and low-immunity. The high-immunity and moderate-immunity groups had higher ImmuneScores, ESTIMATEScores, StromalScores, and lower tumor purity than that of the low-immunity group in both sets. Additionally, the patients from the high-immunity and moderate-immunity groups had longer survival than patients from low-immunity group in both discovery set and validation set (HR = 2.54, 95% CI: 1.56–4.13, p < 0.01; HR = 2.75, 95% CI: 1.24–6.11, p = 0.01).

Conclusion

In summary, we defined a novel immunotype of ccRCC. The immune types could be used as a clinical predictive tool to identify ccRCC patients with different survival. In addition, the immune-related biological signaling pathway also brought new insights on the mechanism of ccRCC.

An Effective Strategy to Develop Potent and Selective Antifungal Agents from Cell Penetrating Peptides in Tackling Drug-Resistant Invasive Fungal Infections

The high mortality rate of invasive fungal infections and quick emergence of drug-resistant fungal pathogens urgently call for potent antifungal agents. Inspired by the cell penetrating peptide (CPP) octaarginine (R8), we elongated to 28 residues poly(d,l-homoarginine) to obtain potent toxicity against both fungi and mammalian cells. Further incorporation of glutamic acid residues shields positive charge density and introduces partial zwitterions in the obtained optimal peptide polymer that displays potent antifungal activity against drug-resistant fungi superior to antifungal drugs, excellent stability upon heating and UV exposure, negligible in vitro and in vivo toxicity, and strong therapeutic effects in treating invasive fungal infections. Moreover, the peptide polymer is insusceptible to antifungal resistance owing to the unique CPP-related antifungal mechanism of fungal membrane penetration followed by disruption of organelles within fungal cells. All these merits imply the effectiveness of our strategy to develop promising antifungal agents.

Microbial Metabolite Inspired β-Peptide Polymers Displaying Potent and Selective Antifungal Activity

Potent and selective antifungal agents are urgently needed due to the quick increase of serious invasive fungal infections and the limited antifungal drugs available. Microbial metabolites have been a rich source of antimicrobial agents and have inspired the authors to design and obtain potent and selective antifungal agents, poly(DL-diaminopropionic acid) (PDAP) from the ring-opening polymerization of β-amino acid N-thiocarboxyanhydrides, by mimicking ε-poly-lysine. PDAP kills fungal cells by penetrating the fungal cytoplasm, generating reactive oxygen, and inducing fungal apoptosis. The optimal PDAP displays potent antifungal activity with minimum inhibitory concentration as low as 0.4 µg mL^-1 against Candida albicans, negligible hemolysis and cytotoxicity, and no susceptibility to antifungal resistance. In addition, PDAP effectively inhibits the formation of fungal biofilms and eradicates the mature biofilms. In vivo studies show that PDAP is safe and effective in treating fungal keratitis, which suggests PDAPs as promising new antifungal agents.

Short Guanidinium-Functionalized Poly(2-oxazoline)s Displaying Potent Therapeutic Efficacy on Drug-Resistant Fungal Infections

New antifungals are urgently needed to combat invasive fungal infections, due to limited types of available antifungal drugs and frequently encountered side effects, as well as the quick emergence of drug-resistance. We previously developed amine-pendent poly(2-oxazoline)s (POXs) as synthetic mimics of host defense peptides (HDPs) to have antibacterial properties, but with poor antifungal activity. Hereby, we report the finding of short guanidinium-pendent POXs, inspired by cell-penetrating peptides, as synthetic mimics of HDPs to display potent antifungal activity, superior mammalian cells versus fungi selectivity, and strong therapeutic efficacy in treating local and systemic fungal infections. Moreover, the unique antifungal mechanism of fungal cell membrane penetration and organelle disruption explains the insusceptibility of POXs to antifungal resistance. The easy synthesis and structural diversity of POXs imply their potential as a class of promising antifungal agents.

Heterochiral β-Peptide Polymers Combating Multidrug-Resistant Cancers Effectively without Inducing Drug Resistance

Multidrug resistance to chemotherapeutic drugs is one of the major causes for the failure of cancer treatment. Therefore, there is an urgent need to develop anticancer agents that can combat multidrug-resistant cancers effectively and mitigate drug resistance. Here, we report a rational design of anticancer heterochiral β-peptide polymers as synthetic mimics of host defense peptides to combat multidrug-resistant cancers. The optimal polymer shows potent and broad-spectrum anticancer activities against multidrug-resistant cancer cells and is insusceptible to anticancer drug resistance owing to its membrane-damaging mechanism. The in vivo study indicates that the optimal polymer efficiently inhibits the growth and distant transfer of solid tumors and the metastasis and seeding of circulating tumor cells. Moreover, the polymer shows excellent biocompatibility during anticancer treatment on animals. In addition, the β-peptide polymers address those prominent shortcomings of anticancer peptides and have superior stability against proteolysis, easy synthesis in large scale, and low cost. Collectively, the structural diversity and superior anticancer performance of β-peptide polymers imply an effective strategy in designing and finding anticancer agents to combat multidrug-resistant cancers effectively while mitigating drug resistance.

[Correlation analysis of smell and taste loss with COVID-19 outbreak trend based on big data of internet]

Objective: To analyze the correlation between loss of smell/taste and the number of real confirmed cases of coronavirus disease 2019 (COVID-19) worldwide based on Google Trends data, and to explore the guiding role of smell/taste loss for the COVID-19 prevention and control. Methods: "Loss of smell" and "loss of taste" related keywords were searched in the Google Trends platform, the data were obtained from Jan. 1 2019 to Jul. 11 2021. The daily and newly confirmed COVID-19 case number were collected from World Health Organization (WHO) since Dec. 30 2019. All data were statistically analyzed by SPSS 23.0 software. The correlation was finally tested by Spearman correlation analysis. Results: A total of data from 80 weeks were collected. The retrospective analysis was performed on the new trend of COVID-19 confirmed cases in a total of 186 292 441 cases worldwide. Since the epidemic of COVID-19 was recorded on the WHO website, the relative searches related to loss of smell/taste in the Google Trends platform had been increasing globally. The global relative search volumes of "loss of smell" and "loss of taste" on Google Trends was 10.23±2.58 and 16.33±2.47 before the record of epidemic while 80.25±39.81 and 80.45±40.04 after (t value was 8.67, 14.43, respectively, both P<0.001). In the United States and India, the relative searches for "loss of smell" and "loss of taste" after the record of epidemic were also much higher than before (all P<0.001). The correlation coefficients between the trend of weekly new COVID-19 cases and the Google Trends of "loss of smell" in the global, United States, and India was 0.53, 0.76, and 0.82 respectively (all P<0.001), the correlation coefficients with Google Trends of "loss of taste" was 0.54, 0.78, and 0.82 respectively (all P<0.001). The lowest and highest point of loss of smell/taste search curves of Google Trends in different periods appeared 7 to 14 days earlier than that of the weekly newly COVID-19 confirmed cases curves, respectively. Conclusions: There is a significant positive correlation between the number of newly confirmed cases of COVID-19 worldwide and the amount of keywords, such as "loss of smell" and "loss of taste", retrieved in Google Trends. The trend of big data based on Google Trends might predict the outbreak trend of COVID-19 in advance.

Secondary Amine Pendant β-Peptide Polymers Displaying Potent Antibacterial Activity and Promising Therapeutic Potential in Treating MRSA-Induced Wound Infections and Keratitis

Interest in developing antibacterial polymers as synthetic mimics of host defense peptides (HPDs) has accelerated in recent years to combat antibiotic-resistant bacterial infections. Positively charged moieties are critical in defining the antibacterial activity and eukaryotic toxicity of HDP mimics. Most examples have utilized primary amines or guanidines as the source of positively charged moieties, inspired by the lysine and arginine residues in HDPs. Here, we explore the impact of amine group variation (primary, secondary, or tertiary amine) on the antibacterial performance of HDP-mimicking β-peptide polymers. Our studies show that a secondary ammonium is superior to either a primary ammonium or a tertiary ammonium as the cationic moiety in antibacterial β-peptide polymers. The optimal polymer, a homopolymer bearing secondary amino groups, displays potent antibacterial activity and the highest selectivity (low hemolysis and cytotoxicity). The optimal polymer displays potent activity against antibiotic-resistant bacteria and high therapeutic efficacy in treating MRSA-induced wound infections and keratitis as well as low acute dermal toxicity and low corneal epithelial cytotoxicity. This work suggests that secondary amines may be broadly useful in the design of antibacterial polymers.

Biodegradable Peptide Polymers as Alternatives to Antibiotics Used in Aquaculture

The pressure of antimicrobial resistance has forced many countries to reduce or even prohibit the use of antibiotics in feed. Therefore, it is in urgent need to develop alternatives to...

A Cryptic Palmitoyl Chain Involved in Safracin Biosynthesis Facilitates Post-NRPS Modifications

This study confirmed the participation of a cryptic palmitoyl fatty acyl chain in the biosynthesis of safracin and unraveled a previously ignored peptidase for the removal of the precursor. Furthermore, the post-assembly line tailoring steps are extensively studied in terms of the methyltransferase SacI-catalyzed N-methylation and the FAD-dependent monooxygenase SacJ-catalyzed A-ring oxidation. The timing of these post-NRPS steps is also addressed in this work.

Superfast and Water-Insensitive Polymerization on α-Amino Acid N-Carboxyanhydrides to Prepare Polypeptides Using Tetraalkylammonium Carboxylate as the Initiator

We design the tetraalkylammonium carboxylate-initiated superfast polymerization on α-amino acid N-carboxyanhydrides (NCA) for efficient synthesis of polypeptides. Carboxylates, as a new class of initiator for NCA polymerization, can initiate the superfast NCA polymerization without the need of extra catalysts and the polymerization can be operated in open vessels at ambient condition without the use of glove box. Tetraalkylammonium carboxylate-initiated polymerization on NCA easily affords block copolymers with at least 15 blocks. Moreover, this method avoids tedious purification steps and enables direct polymerization on crude NCAs in aqueous environments to prepare polypeptides and one-pot synthesis of polypeptide nanoparticles. These advantages and the mild polymerization condition of tetraalkylammonium carboxylate-initiated NCA polymerization imply its great potential in functional exploration and application of polypeptides.

Recent Advances in Microfluidic Platforms for Programming Cell-Based Living Materials

Cell-based living materials, including single cells, cell-laden fibers, cell sheets, organoids, and organs, have attracted intensive interests owing to their widespread applications in cancer therapy, regenerative medicine, drug development, and so on. Significant progress in materials, microfabrication, and cell biology have promoted the development of numerous promising microfluidic platforms for programming these cell-based living materials with a high-throughput, scalable, and efficient manner. In this review, the recent progress of novel microfluidic platforms for programming cell-based living materials is presented. First, the unique features, categories, and materials and related fabrication methods of microfluidic platforms are briefly introduced. From the viewpoint of the design principles of the microfluidic platforms, the recent significant advances of programming single cells, cell-laden fibers, cell sheets, organoids, and organs in turns are then highlighted. Last, by providing personal perspectives on challenges and future trends, this review aims to motivate researchers from the fields of materials and engineering to work together with biologists and physicians to promote the development of cell-based living materials for human healthcare-related applications.

Addressing MRSA infection and antibacterial resistance with peptoid polymers

Methicillin-Resistant Staphylococcus aureus (MRSA) induced infection calls for antibacterial agents that are not prone to antimicrobial resistance. We prepare protease-resistant peptoid polymers with variable C-terminal functional groups using a ring-opening polymerization of N-substituted N-carboxyanhydrides (NNCA), which can provide peptoid polymers easily from the one-pot synthesis. We study the optimal polymer that displays effective activity against MRSA planktonic and persister cells, effective eradication of highly antibiotic-resistant MRSA biofilms, and potent anti-infectious performance in vivo using the wound infection model, the mouse keratitis model, and the mouse peritonitis model. Peptoid polymers show insusceptibility to antimicrobial resistance, which is a prominent merit of these antimicrobial agents. The low cost, convenient synthesis and structure diversity of peptoid polymers, the superior antimicrobial performance and therapeutic potential in treating MRSA infection altogether imply great potential of peptoid polymers as promising antibacterial agents in treating MRSA infection and alleviating antibiotic resistance.

Antibiotic resistance is a major issue in medicine and new antimicrobials for treating resistant infection are needed. Here, the authors report on antibacterial peptoid polymers, prepared via NNCA ring-opening polymerization, demonstrating antibacterial function against MRSA in vitro and in in vivo infection models.

Gender differences in the relationships between different types of childhood trauma and resilience on depressive symptoms among Chinese adolescents

Growing studies have paid attention to the relationships between childhood trauma, resilience and depressive symptoms. Depression is more common in girls, while gender differences in these associations have been rarely studied. Yet the study will be beneficial for prevention and intervention of depression in adolescents. The aim of this study is to examine gender differences in the effects of different types of childhood trauma and resilience on depressive symptoms. Data was collected from 6510 students (3408 males, aged 10-17 years) in Wuhan, Hubei, China from 2015 to 2016. Participants completed a self-report questionnaire assessing childhood trauma, resilience, and depressive symptoms. Multiple regression analysis was used to determine gender differences in the relationships between childhood trauma, resilience and depressive symptoms. We found that childhood trauma was positively related to depressive symptoms for both genders, but the relationship in females was stronger than in males. No significant gender difference was found in the independent effect of resilience to depressive symptoms. Resilience moderated the effects of emotional abuse, physical abuse and sexual abuse on depressive symptoms in both males and females. However, the interaction effect of resilience with emotional abuse on depressive symptoms was stronger in females compared to males. Our findings revealed gender differences in the links between childhood trauma and depressive symptoms among adolescents, and the interaction effect of resilience and childhood emotional abuse on depressive symptoms was gender-specific. These provide the basis for gender-special prevention and intervention measures for depressive symptoms in adolescents.

Evaluation of Single-Cell Cytokine Secretion and Cell-Cell Interactions with a Hierarchical Loading Microwell Chip

Comprehensive evaluation of single T cell functions such as cytokine secretion and cytolysis of target cells is greatly needed in adoptive cell therapy (ACT) but has never been fully fulfilled by current approaches. Herein, we develop a hierarchical loading microwell chip (HL-Chip) that aligns multiple cells and functionalized beads in a high-throughput microwell array with single-cell/bead precision based on size differences. We demonstrate the potential of the HL-Chip in evaluating single T cell functions by three applications: high-throughput longitudinal secretory profiling of single T cells, large-scale evaluation of cytolytic activity of single T cells, and integrated T cell-tumor cell interactions. The HL-Chip is a simple and robust technology that constructs arrays of defined cell/object combinations for multiple measurements and material retrieval.

Correction to: Clinical characteristics of 14 COVID-19 deaths in Tianmen, China: a single-center retrospective study

An amendment to this paper has been published and can be accessed via the original article.

Clinical characteristics of 14 COVID-19 deaths in Tianmen, China: a single-center retrospective study

BACKGROUND

The treatment of critically ill patients with COVID-19 who were hospitalized in Wuhan has been reported. However, the clinical characteristics of patients who died of COVID-19 in regions with relatively scarce healthcare resources remain unknown.

METHODS

In this retrospective study, a total of 14 patients who were admitted from January 18 to February 11, 2020 and died of COVID-19 were evaluated. The epidemiological, symptomatic, laboratory, radiological and treatment records were reviewed and analyzed.

RESULTS

The mean age of the 14 patients was 56.7 (SD 15.3) years, and 8 (57.1%) were older than 50 years. Eight (57.1%) were men, and 11 (78.6%) had one or more high risk factors. The most common chronic diseases among these patients were cardiovascular disease (7, 50.0%), hypertension (6, 42.9%), and chronic kidney disease (5, 35.7%). General symptoms included cough (12, 85.7%), fever (11, 78.6%), and dyspnea (10, 71.4%). The median duration from the onset of symptoms to death was 11 (IQR 6.5-19.5) days, and the median duration from admission to death was 4.5 (1.0-11.8) days. Patients who died within 4.5 days had more severe pulmonary lesions, significantly reduced lymphocytes and elevated C-reactive protein (CRP). Most patients had organ dysfunction, including 13 (92.9%) with acute respiratory distress syndrome (ARDS), 4 (28.6%) with cardiac injury, 3 (21.4%) with acute kidney injury, and 3 (21.4%) with liver dysfunction.

CONCLUSIONS

Elderly SARS-CoV-2-infected patients with comorbidities, especially those with ARDS and severe chest CT findings on admission, are at increased risk of death and deserve special attention and quality medical treatment.

The membrane-targeting mechanism of host defense peptides inspiring the design of polypeptide-conjugated gold nanoparticles exhibiting effective antibacterial activity against methicillin-resistant Staphylococcus aureus

Multidrug-resistant bacterial infections are a grand challenge to global medical and health systems. Therefore, it is urgent to develop versatile antibacterial strategies that can combat bacterial resistance without displaying toxicity. Here, we synthesize antibacterial polypeptide-conjugated gold nanoparticles that exhibit potent antibacterial activities against clinically isolated multiple drug resistance Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus, and excellent in vitro and in vivo biocompatibility. The antibacterial mechanism study indicates that over-production of reactive oxygen species results in the killing of bacteria. The overall antibacterial performance of these polypeptide-conjugated gold nanoparticles and the convenient synthesis of these polypeptides via lithium hexamethyldisilazide-initiated fast ring-opening polymerization on α-amino acid N-carboxyanhydride imply the potential application of this strategy in treating bacterial infections.

Precisely Tunable Ion Sieving with an Al13-Ti3C2Tx Lamellar Membrane by Controlling Interlayer Spacing

Two-dimensional (2D) membranes exhibit exceptional properties in molecular separation and transport, which reveals their potential use in various applications. However, ion sieving with 2D membranes is severely restrained due to intercalation-induced swelling. Here, we describe how to efficiently stabilize the lamellar architecture using Keggin Al₁₃ polycations as pillars in a Ti₃C₂T_x membrane. More importantly, interlayer spacing can be easily adjusted with angstrom precision over a wide range (2.7-11.2 Å) to achieve selective and tunable ion sieving. A membrane with narrow d-spacing demonstrated enhanced selectivity for monovalent ions. When applied in a forward osmosis desalination process, this membrane exhibited high NaCl exclusion (99%) with a fast water flux (0.30 L m^-2 h^-1 bar^-1). A membrane with wide d-spacing showed notable selectivity, which was dependent on the cation valence. When it was applied to acid recovery from iron-based industrial wastewater, the membrane showed good H⁺/Fe²⁺ selectivity, which makes it a promising substitute for traditional polymeric membranes. Thus, we introduce a possible route to construct 2D membranes with appropriate structures to satisfy different ion-sieving requirements in diverse environment-, resource-, and energy-related applications.

Multiplex and visual detection of African Swine Fever Virus (ASFV) based on Hive-Chip and direct loop-mediated isothermal amplification

African swine fever is caused by African swine fever virus (ASFV), and has a mortality rate approaching 100%. It has already caused tremendous economy lost around the world. Without effective vaccine, rapid and accurate on-site detection plays an indispensable role in controlling outbreaks. Herein, by combining Hive-Chip and direct loop-mediated isothermal amplification (LAMP), we establish a multiplex and visual detection platform. LAMP primers targeting five ASFV genes (B646L, B962L, C717R, D1133L, and G1340L) were designed and pre-fixed in Hive-Chip. On-chip LAMP showed the limits of detection (LOD) of ASFV synthetic DNAs and mock samples are 30 and 50 copies per microliter, respectively, and there is no cross-reaction among the target genes. The overall performance of our platform is comparable to that of the commercial kits. From sample preparation to results readout, the entire process takes less than 70 min. Multiplex detection of real samples of ASFV and other swine viruses further demonstrates the high sensitivity and specificity of Hive-Chip. Overall, our platform provides a promising option for on-site, fast and accurate detection of ASFV.

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Hive-Chip firstly realized simultaneous detection of multiple genes of ASFV, largely avoiding false-negative results.

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Without nucleic acid extraction, direct LAMP was firstly incorporated into the Hive-Chip for visual detection.

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Because very little operation and no complicate instrument is required, on-site detection is possible for this platform.

Identification of seven long noncoding RNAs signature for prediction of biochemical recurrence in prostate cancer

Accumulating evidence suggested that long noncoding RNAs (lncRNAs) possess a potential role in prostate cancer (PCa) diagnosis and prognosis. Rapid biochemical recurrence (BCR) is considered as a sign for clinical recurrence metastasis and PCa-specific mortality. Hence, the aim of the present study was to identify a lncRNA signature that can predict BCR of PCa accurately. Bioinformatics analysis, Kaplan–Meier analyses, Cox regression analyses, and Gene Set Enrichment Analysis (GSEA) were performed in a publicly available database with 499 PCa tissues and 52 matched normal tissues. A signature was identified. All these lncRNAs were differentially expressed between tumor and normal tissues and differentially expressed between high Gleason score and low Gleason score tissues. Furthermore, we developed a seven lncRNAs signature that can predict PCa BCR. Patients classified into low-risk group showed better BCR survival significantly than the patients in the high-risk group (hazard ratio = 0.32, 95% CI: 0.20–0.52, concordance index = 0.63). The area under the curve was 0.68 for BCR. The signature also had good discrimination for BCR in men with Gleason 7 PCa. In conclusion, our results suggest that the seven lncRNAs signature is a new biomarker of BCR and high risk in PCa. In addition, the individual lncRNA warrants further study to uncover the associated mechanisms of PCa progression and the signature could be used to design direct clinical trials for adjuvant therapy.

Preparation and Thermal Analysis of Flame-retardant Chitosan Thin Films on Ammonium Polyphosphate Treated Reconstituted Tobacco Sheet

Background:

Burning temperature is one of the most important factors affecting the chemical structure of the smoke and the addition of reconstituted tobacco sheet to cut tobacco has been widely used by the tobacco industry to reduce the cost of cigarettes and the health risks of smoking.

Methods:

A flame retardant film, made from chitosan and ammonium polyphosphate, has been coated on the surface of the reconstituted tobacco sheet substrate by Layer-by-Layer and spray coating techniques. The thermal degradation properties and flame retardancy of these reconstituted tobacco sheets were analyzed by TG-FTIR and micro-scale combustion calorimetry.

Results:

It was found that the reconstituted tobacco sheet with the ratio of chitosan (5%) and ammonium polyphosphate (3%) film coating showed significant reductions in the peak heat release rate (50.7%), total heat release (35.8%) and the highest temperature in the temperature distribution diagram (77°C). The main gases released during the pyrolysis of these reconstituted tobacco sheet samples were H2O, CO2, CO, NH3, carbonyl compounds and the presence of film coating changed the formation of evolved volatile products and formed less gaseous products except NH3 during the thermal decomposition process.

Conclusion:

The coating film can greatly enhance the char forming ability and reduce the flammability of reconstituted tobacco sheet, and therefore, reduce the health risks of smoking with the addition of these reconstituted tobacco sheets.

Transcriptional regulation of strigolactone signalling in Arabidopsis

Plant hormones known as strigolactones control plant development and interactions between host plants and symbiotic fungi or parasitic weeds^1-4. In Arabidopsis thaliana and rice, the proteins DWARF14 (D14), MORE AXILLARY GROWTH 2 (MAX2), SUPPRESSOR OF MAX2-LIKE 6, 7 and 8 (SMXL6, SMXL7 and SMXL8) and their orthologues form a complex upon strigolactone perception and play a central part in strigolactone signalling^5-10. However, whether and how strigolactones activate downstream transcription remains largely unknown. Here we use a synthetic strigolactone to identify 401 strigolactone-responsive genes in Arabidopsis, and show that these plant hormones regulate shoot branching, leaf shape and anthocyanin accumulation mainly through transcriptional activation of the BRANCHED 1, TCP DOMAIN PROTEIN 1 and PRODUCTION OF ANTHOCYANIN PIGMENT 1 genes. We find that SMXL6 targets 729 genes in the Arabidopsis genome and represses the transcription of SMXL6, SMXL7 and SMXL8 by binding directly to their promoters, showing that SMXL6 serves as an autoregulated transcription factor to maintain the homeostasis of strigolactone signalling. These findings reveal an unanticipated mechanism through which a transcriptional repressor of hormone signalling can directly recognize DNA and regulate transcription in higher plants.

A novel gene signature to predict immune infiltration and outcome in patients with prostate cancer

Prostate cancer (PCa) is one of the most common malignancies in male. We aim to establish a novel gene signature for immune infiltration and outcome (biochemical recurrence (BCR) and overall survival (OS)) of patients with prostate cancer (PCa) to augment Gleason patterns for evaluating prognosis and managing patients undergoing radical prostatectomy (RP). Combined with our microarray data and the Cancer Genome Atlas Project (TCGA) database (discovery set), we identified a six-gene signature. The Gene Expression Omnibus (GEO) database served as the test set. The databases of Fudan University Shanghai Cancer Center (FUSCC) and Third Affiliated Hospital of Nantong University (TAHNU) served as an external validation set. Immunohistochemistry was used to investigate the relationship between risk groups and the immune infiltrate. We identified a six-gene signature to predict immune cell infiltration and outcome of PCa patients. The AUC values used to predict early BCR in the discovery, test, FUSCC, and TAHNU sets were 0.73, 0.76, 0.72, and 0.81, respectively. Low-risk score patients in each dataset experienced significantly longer OS (P = .01, 0.04, 0.02, respectively). The signature also predicted high regulatory T cells (Tregs) and M2-polarized macrophages infiltration in high-risk score patients with PCa. Additionally, high mutation load, related signal pathways, and sensitivity to anticancer drugs that correlated with high-risk score of cancer progression and death were also identified. The six-gene signature may improve prognostic information, serve as a prognostic tool to manage patients after RP, and advance basic studies of PCa.

Personality traits and depressive symptoms: The moderating and mediating effects of resilience in Chinese adolescents

BACKGROUND

Various studies showed that personality traits and resilience might have impacts on depressive symptoms, separately. However, the relationships among personality traits, resilience and depressive symptoms are still undefined. Thus, this study tried to explore the potential effect of resilience on the associations between personality traits and depressive symptoms in Chinese adolescents.

METHODS

Adolescents (n = 6019) aged 10-17 years were recruited from nine schools in Wuhan, China. Depressive symptoms, personality traits, and resilience were evaluated by the Center for Epidemiologic Studies Depression scale (CES-D), the NEO-Five Factor Inventory (NEO-FFI), and the Connor-Davidson Resilience Scale (CD-RISC), respectively.

RESULTS

Neuroticism was positively associated with depressive symptoms, whereas extraversion, openness, agreeableness, and conscientiousness were negatively associated with depressive symptoms. Resilience separately moderated the associations of neuroticism, extraversion, agreeableness, and conscientiousness with depressive symptoms, and partly mediated the associations of all five personality traits with depressive symptoms.

LIMITATIONS

This study is a cross sectional study and cannot ascertain the causal relationships between the variables. Also self-reported questionnaire instruments were used in the data collection.

CONCLUSIONS

These findings suggested that resilience might play moderating and mediating roles in the associations of personality traits with depressive symptoms, and prompted that it was critical to improve resilience and develop adaptive personality traits in the prevention and intervention of depression in adolescents.

[Relationships among personality traits, resilience and depressive symptoms of students in Wuhan City]

OBJECTIVE

To investigate the relationships among personality traits, resilience and depressive symptoms of primary and high school students.

METHODS

Totally 6019 students aged 10-17 from 5 primary schools(grades 5-6), 3 junior middle schools(grades 7-9) and 2 senior high schools(grade 1) years were selected by cluster sampling in Wuhan, from September 2015 to January 2016. Among them, there were 2420 primary school students, 2912 junior high school students and 687 senior high school students. In addition, 3071 students were male, 2948 students were female. Participants were asked to complete self-report questionnaires, including demographic characteristic questionnaire, the center for epidemiological studies depression scale(CES-D), the connor davidson resilience scale(CD-RISC) and the NEO-five factor inventory(NEO-FFI). Multivariate Logistic regression analysis was used to analyze the influence factors of depressive symptoms in primary and high school students.

RESULTS

The detection rate of depressive symptoms was 10. 5%(635/6019). Multivariate Logistic regression analysis showed that after adjusting for grade and family history of depression, neuroticism(OR=4. 53, 95% CI 3. 88-5. 28) and openness(OR=1. 33, 95% CI 1. 18-1. 50) were positively associated with depressive symptoms. But the higher level of extraversion(OR=0. 70, 95% CI 0. 62-0. 79) and conscientiousness(OR=0. 77, 95% CI 0. 67-0. 90) and resilience(OR=0. 77, 95% CI 0. 67-0. 88) were associated with lower risk of depressive symptoms in primary and high school students.

CONCLUSION

Neuroticism and openness might be positively correlated with, whereas extraversion, conscientiousness and resilience might be negatively correlated with the onsets of depressive symptoms in primary and secondary school students. Thus, developing adaptive personality and improving resilience would contribute to the prevention and intervention of depression in primary and high school students.

Conditional disease-free survival in high-risk renal cell carcinoma treated with sunitinib

BACKGROUND

Disease-free survival (DFS) did not reflect accurate individual prognosis after initial diagnosis. As conditional DFS (CDFS) could provide dynamic prognostic information, we evaluated CDFS in these patients treated with or without sunitinib.

RESULTS

A total of 1329 patients with median follow-up 6.54 years were enrolled. CDFS improved continuously with disease-free survivorship increasing in both sunitinib and placebo group with minimal difference. In placebo arm, the CDFS of surviving to five year after living 1, 2, 3, and 4 years were 65%, 78%, 87%, and 95% (observed 5-year DFS: 51%). Dynamic changes of HR showed adjuvant sunitinib decrease relapse risks during the first 1.5 years after surgery (P < 0.03).

CONCLUSIONS

Our study provided contemporary data of CDFS and change of relapse HR in high-risk ccRCC patients after adjuvant sunitinib or placebo. The remarkable improvement in CDFS highlighted the importance of disease-free interval as a strong indicator in patient counseling and surveillance planning.

MATERIALS AND METHODS

The primary end point was CDFS and the second end point was smooth hazard ratios (HR) for the prediction of relapses. The differences of conditional survival were compared with the calculation of d value.

Dual functional β-peptide polymer-modified resin beads for bacterial killing and endotoxin adsorption

Background

Bacterial infections and endotoxin contaminations are serious problems in the production/manufacture of food, water, drinks, and injections. The development of effective materials to kill bacteria and adsorb endotoxins, particularly those caused by gram-negative bacteria, represents a major step toward improved safety. As synthetic mimic of host defense peptides, β-peptide polymers are not susceptible to bacterial resistance and exhibit potent bacteria-killing abilities upon antibiotic-resistant bacteria. This study investigated the potential of synthetic β-peptide polymer-modified polyacrylate (PA) beads to kill bacteria and remove endotoxin, i.e. lipopolysaccharide (LPS), produced by these bacteria.

Results

Synthetic β-peptide polymer-modified PA beads displayed strong antimicrobial activity against Escherichia coli and methicillin-resistant Staphylococcus aureus, as well as excellent biocompatibility. In addition, these β-peptide polymer-modified beads removed around 90% of the endotoxins, even at 200 EU/mL of LPS, a very high concentration of LPS.

Conclusions

β-peptide polymer-modified PA beads are efficient in bacterial killing and endotoxin adsorption. Hence, these modified beads demonstrate the potential application in the production/manufacture of food, water, drinks, and injections.

Microfluidic Cell Trap Arrays for Single Hematopoietic Stem/Progenitor Cell Behavior Analysis

Hematopoietic stem/progenitor cell (HSPC) mobilization from the bone marrow to the bloodstream is a required step for blood cell renewal, and HSPC motility is a clinically relevant standard for peripheral blood stem cell transplantation. Individual HSPCs exhibit considerable heterogeneity in motility behaviors, which are subject to complex intrinsic and extrinsic regulatory mechanisms. Motility-based cell sorting is then demanded to fulfill the study of such mechanism complexity. However, due to the HSPC heterogeneity and difficulty in monitoring cell motility, such a platform is still not available. With the recent development of microfluidics technology, motility-based monitoring, sorting, collecting, and analysis of HSPC behaviors are highly possible and achievable if fluid channels and structures are correctly engineered. Here, a new design of microfluidic arrays for single-cell trapping is presented, enabling high-throughput analysis of individual HSPC motility and behavior. Using these arrays, it is observed that HSPC motility is positively correlated with CD34 asymmetric inheritance and cell differentiation. Transcriptomic analysis of HSPCs sorted according to motility reveals changes in expression of genes associated with the regulation of stem-cell maintenance. Ultimately, this novel, physical cell-sorting system can facilitate the screening of HSPC mobilization compounds and the analysis of signals driving HSPC fate decisions.

Inactivation of the AMPK-GATA3-ECHS1 Pathway Induces Fatty Acid Synthesis That Promotes Clear Cell Renal Cell Carcinoma Growth

The tumorigenic role and underlying mechanisms of lipid accumulation, commonly observed in many cancers, remain insufficiently understood. In this study, we identified an AMP-activated protein kinase (AMPK)-GATA-binding protein 3 (GATA3)-enoyl-CoA hydratase short-chain 1 (ECHS1) pathway that induces lipid accumulation and promotes cell proliferation in clear cell renal cell carcinoma (ccRCC). Decreased expression of ECHS1, which is responsible for inactivation of fatty acid (FA) oxidation and activation of de novo FA synthesis, positively associated with ccRCC progression and predicted poor patient survival. Mechanistically, ECHS1 downregulation induced FA and branched-chain amino acid (BCAA) accumulation, which inhibited AMPK-promoted expression of GATA3, a transcriptional activator of ECHS1. BCAA accumulation induced activation of mTORC1 and de novo FA synthesis, and promoted cell proliferation. Furthermore, GATA3 expression phenocopied ECHS1 in predicting ccRCC progression and patient survival. The AMPK-GATA3-ECHS1 pathway may offer new therapeutic approaches and prognostic assessment for ccRCC in the clinic. SIGNIFICANCE: These findings uncover molecular mechanisms underlying lipid accumulation in ccRCC, suggesting the AMPK-GATA3-ECHS1 pathway as a potential therapeutic target and prognostic biomarker.

Tacrolimus alleviates Ox-LDL damage through inducing vascular endothelial autophagy

OBJECTIVE

To study the protective effect of tacrolimus on vascular endothelium injured by oxidized low-density lipoprotein (ox-LDL) and its mechanism.

MATERIALS AND METHODS

Human umbilical vein endothelial cells were used as objects of study, and divided into control group, tacrolimus group and autophagy inhibition group. Control group received no ox-LDL, while tacrolimus group and autophagy inhibition group were treated with ox-LDL (100 μg/mL) for 3 h. Tacrolimus group was pre-treated with tacrolimus (100 nM) for 0.5 h, and the autophagy inhibition group was pre-treated with 3-methyladenine (3-MA) (10 mM) and tacrolimus (100 nM) for 0.5 h. The cell viability was detected via cell counting kit 8 (CCK8) assay, the cell apoptosis ratio was detected via flow cytometry and Hoechst staining, and the releases of superoxide dismutase (SOD), reactive oxygen species (ROS) and other cytokines were detected using the kit. Moreover, the autophagy level was detected via LC3 fluorescence staining, and the autophagy- and apoptosis-related molecules were detected via polymerase chain reaction (PCR) and Western blotting.

RESULTS

In the absence of ox-LDL, neither tacrolimus nor 3-MA had an effect on the cell viability. After the addition of ox-LDL, the cell viability was significantly decreased, whereas tacrolimus could alleviate such damage to cells. Flow cytometry and Hoechst staining proved that tacrolimus could reduce the proportion of apoptotic cells induced by ox-LDL, while PCR and Western blotting confirmed the decreased expression of apoptosis-related proteins in tacrolimus group. 3-MA could up-regulate the ratio of apoptosis and the expressions of apoptosis-related proteins. The detection of SOD and ROS showed that ox-LDL could induce the cell oxidative stress injury, whereas tacrolimus could inhibit such an effect. The addition of 3-MA inhibited the effect of tacrolimus. Besides, LC3 fluorescence staining, PCR and Western blotting revealed that ox-LDL could induce the autophagy, while tacrolimus could enhance the autophagy. After the addition of 3-MA, the intracellular autophagy level was significantly inhibited.

CONCLUSIONS

Tacrolimus protects vascular endothelial cells from ox-LDL damage through inducing the autophagy.

Liraglutide ameliorates non-alcoholic steatohepatitis by inhibiting NLRP3 inflammasome and pyroptosis activation via mitophagy

Non-alcoholic steatohepatitis (NASH) is a key step in the progression of non-alcoholic fatty liver disease (NAFLD), which causes serious health problems worldwide. The nucleotide-binding oligomerization domain, leucine-rich repeat-containing receptor-containing pyrin domain 3 (NLRP3) inflammasome and pyroptosis play crucial roles in the progression of NASH. Our team has provided clinical evidence of the effects of glucagon-like peptide-1 (GLP-1) on the improvement in liver function and histological resolution of NAFLD. Preliminary work has demonstrated that GLP-1 inhibited NLRP3 inflammasome activation in a mouse model of NAFLD. We further explored the potential molecular mechanisms underlying the anti-inflammatory effect of liraglutide, a long-acting GLP-1 analog, in the treatment of NASH. We established a HepG2 cell model of NASH using double stimulation with palmitic acid and lipopolysaccharide to assess NLRP3 inflammasome and pyroptotic cell activity and to evaluate mitochondrial function and mitophagy. Liraglutide reduced lipid accumulation, inhibited NLRP3 inflammasome and pyroptosis activation, attenuated mitochondrial dysfunction and reactive oxygen species generation, augmented mitophagy in hepatocytes. Mitophagy inhibition with 3-methyladenine/PINK1-directed siRNA weakened the liraglutide-mediated suppression of inflammatory injury. We propose that liraglutide suppresses NLRP3 inflammasome-induced hepatocyte pyroptosis via mitophagy to slow the progression of NASH.

Host defense peptide mimicking poly-β-peptides with fast, potent and broad spectrum antibacterial activities

Microbial infections have always been serious challenges to human health considering that antibiotics almost inevitably induce microbial resistance. Therefore, it is urgent to develop a new antibacterial agent that is active against drug-resistant bacteria and is less susceptible to microbial resistance. In this work, a series of host defense peptide (HDP) mimicking antibacterial poly-β-peptides were synthesized, characterized and evaluated for their biological activities. The best poly-β-peptide within this study (20 : 80 Bu : DM) displays potent and broad spectrum antibacterial activity against antibiotic-resistant super bugs and low toxicity toward mammalian cells. Moreover, these poly-β-peptides are bactericidal and kill bacteria very fast within 5 min. An antimicrobial resistance test demonstrated that bacteria develop no resistance toward the selected poly-β-peptides even over 1000 generations. Our studies demonstrate that random copolymers of heterochiral poly-β-peptides, without the need for defined secondary structures, can mimic the antimicrobial HDP. These results imply the potential application of these poly-β-peptides as new antimicrobial agents to tackle drug resistant antimicrobial infections.

[Childhood trauma and its correlation with resilience among primary and middle school students in Wuhan city in 2015]

OBJECTIVE

To investigate the prevalence of early trauma and resilience among adolescents in Wuhan, and explore the relationship between early trauma and resilience.

METHODS

Totally 4871 students aged 10-16 years were chosen by cluster sampling in Wuhan city from September to October 2015. All subjects completed self-report questionnaires, including general information, the Childhood Trauma Questionnaire( CTQ), and the Connor Davidson Resilience Scale( CD-RISC).

RESULTS

The mean score of CD-RISC of the total sample was( 64. 70 ± 18. 34). Statistical significance in different gender( t = 5. 373, P<0. 001), age( F = 49. 401, P<0. 001), single child( t = 3. 529, P<0. 001), levels of mother's education( F = 36. 129, P< 0. 001), relationship between parents( F = 89. 831, P < 0. 001), family economic status( F = 36. 547, P<0. 001). The rate of early trauma was 30. 1%. Male( χ~2= 42. 272, P < 0. 001), lower levels of mother 's education( χ~2= 44. 345, P < 0. 001), poorer relationship between parents( χ~2= 133. 045, P < 0. 001), and worse family economic status( χ~2= 31. 231, P<0. 001) were associated with increased risk of early trauma. The scores of emotional abuse, physical abuse, sexual abuse, emotional neglect and physical neglect were negatively correlated with the scores of CD-RISC( r followed by-0. 256, -0. 107, -0. 053, -0. 355 and-0. 308, P<0. 01). Regression analysis implied female, older age, emotional abuse, emotional neglect, and physical neglect( B followed by-0. 156, -0. 117, -0. 109, -0. 214 and-0. 149, P < 0. 01) of primary and middle school students assumed predictive resilience.

CONCLUSION

Emotional abuse, emotional neglect, and physical neglect are negatively associated with resilience among children and adolescent. The result suggest that reducing emotional abuse, emotional neglect and physical neglect experience may contribute to child resilience.