Accelerating the design of pili-enabled living materials using an integrative technological workflow

Bacteria can be programmed to create engineered living materials (ELMs) with self-healing and evolvable functionalities. However, further development of ELMs is greatly hampered by the lack of engineerable nonpathogenic chassis and corresponding programmable endogenous biopolymers. Here, we describe a technological workflow for facilitating ELMs design by rationally integrating bioinformatics, structural biology and synthetic biology technologies. We first develop bioinformatics software, termed Bacteria Biopolymer Sniffer (BBSniffer), that allows fast mining of biopolymers and biopolymer-producing bacteria of interest. As a proof-of-principle study, using existing pathogenic pilus as input, we identify the covalently linked pili (CLP) biosynthetic gene cluster in the industrial workhorse Corynebacterium glutamicum. Genetic manipulation and structural characterization reveal the molecular mechanism of the CLP assembly, ultimately enabling a type of programmable pili for ELM design. Finally, engineering of the CLP-enabled living materials transforms cellulosic biomass into lycopene by coupling the extracellular and intracellular bioconversion ability.

[Opportunities and challenges in an emerging interdisciplinary research field-cardio-oncology]

The field of oncology has made remarkable progress over the past two decades. With the aging of the population, the number of cancer survivors is increasing. At the same time, cancer therapy-related cardiovascular toxicity (CTR-CVT) has become an important cause that seriously affects the quality of life and survival of cancer patients. In this context, cardio-oncology, an emerging interdisciplinary field, emerged. The types and treatment strategies of oncological diseases are heterogeneous, and the management of cancer patients also requires the participation of multiple disciplines. Currently, there are still insufficient clinical research and evidence-based practice in the field of cardio-oncology, resulting in a lack of standardization in its diagnosis and treatment. Additionally, the training model of physicians in cardio-oncology is still being explored. This article provides a comprehensive exploration of the opportunities and challenges faced by physicians and researchers in the field of cardio-oncology. It also delves into the prevailing landscape of clinical research in China and outlines the future training model for physicians in cardio-oncology.

Circadian nuclear receptor Rev-erbalpha is expressed by platelets and potentiates platelet activation and thrombus formation

Background

Adverse cardiovascular events have day/night patterns with peaks in the morning, potentially related to endogenous circadian clock control of platelet activation. Circadian nuclear receptor Rev-erbα is an essential and negative component of the circadian clock.

Purpose

We aim to investigate the expression profile and biological function of Rev-erbα in platelets.

Methods and results

Here we report the presence and functions of circadian nuclear receptor Rev-erbα in human and mouse platelets. Both human and mouse platelet Rev-erbα showed a circadian rhythm that positively correlated with platelet aggregation. Global Rev-erbα knockout and platelet-specific Rev-erbα knockout mice exhibited defective in hemostasis as assessed by prolonged tail-bleeding times. Rev-erbα deletion also reduced ferric chloride-induced carotid arterial occlusive thrombosis, prevented collagen/epinephrine-induced pulmonary thromboembolism, and protected against microvascular microthrombi obstruction and infarct expansion in an acute myocardial infarction model. In vitro thrombus formation assessed by CD41-labeled platelet fluorescence intensity was significantly reduced in Rev-erbα knockout mouse blood. Platelets from Rev-erbα knockout mice exhibited impaired agonist-induced aggregation responses, integrin αIIbβ3 activation and α-granule release. Consistently, pharmacological inhibition of Rev-erbα by specific antagonists decreased platelet activation markers in both mouse and human platelets. Mechanistically, mass spectrometry and co-immunoprecipitation analyses revealed that Rev-erbα potentiated platelet activation via oligophrenin-1-mediated RhoA/ERM (ezrin/radixin/moesin) pathway.

Conclusion

We provide the first evidence that circadian protein Rev-erbα is functionally expressed in platelets and potentiates platelet activation and thrombus formation. Rev-erbα may serve as a novel therapeutic target for managing thrombosis-based cardiovascular disease.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by grants from the National Science Fund for Distinguished Young Scholars (81625002), the National Natural Science Foundation of China (81930007).

Circadian disruption on the susceptibility to sepsis-induced cardiac dysfunction: a prospective multi-modal imaging study

Background

Sepsis is a significant cause of mortality, and cardiac dysfunction is one of the vital predictors for mortality of sepsis. However, the factors associated with the susceptibility to sepsis-induced cardiac dysfunction remain unclear. Disruption of circadian rhythms can profoundly influence cardiac health; however, to the knowledge of the authors, the relationship of circadian disruption to cardiac involvement in patients with sepsis is unknown.

Purpose

We aim to investigate the impact of circadian disruption on the susceptibility to sepsis-induced cardiac dysfunction.

Methods

Study patient data were obtained from the image database of EARLY-MYO-SEPSIS (EARLY assessment of MYOcardial tissue characteristics by multi-modal imaging in SEPSIS) registry, which was a prospective, multi-center registry of sepsis patients who have undergone cardiac magnetic resonance imaging (MRI) and echocardiography from 8 sites (clinical trial number NCT04513795). Cardiac involvement was evaluated using a comprehensive assessment comprising of echocardiography (with global longitudinal strain calculation), cardiac MRI and cardiac biomarker evaluation. Logistic regression was performed to identify independent predictors of left ventricular systolic dysfunction in sepsis.

Results

A total of 216 intensive care unit patients with sepsis was enrolled in the present analysis. Septic patients with a history of circadian disruption (i.e., sleep insufficiency <6 hours) presented more cardiac involvements (as indicated by edema on the cardiac MRI along with cardiac deformation and increased cardiac biomarkers) compared with those without circadian disruption history. Moreover, septic patients with a history of circadian disruption had increased mortality and incidence of heart failure. A history of circadian disruption was identified as an independent predictor of left ventricular systolic dysfunction in sepsis.

Conclusions

Our data from EARLY-MYO-SEPSIS registry demonstrated a previously unappreciated circadian sensitivity to sepsis-induced cardiac dysfunction.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants from the National Science Fund for Distinguished Young Scholars (81625002) and National Natural Science Foundation of China (81930007)

Diatom-inspired multiscale mineralization of patterned protein-polysaccharide complex structures

Marine diatoms construct their hierarchically ordered, three-dimensional (3D) external structures called frustules through precise biomineralization processes. Recapitulating the remarkable architectures and functions of diatom frustules in artificial materials is a major challenge that has important technological implications for hierarchically ordered composites. Here, we report the construction of highly ordered, mineralized composites based on fabrication of complex self-supporting porous structures-made of genetically engineered amyloid fusion proteins and the natural polysaccharide chitin-and performing in situ multiscale protein-mediated mineralization with diverse inorganic materials, including SiO2, TiO2 and Ga2O3. Subsequently, using sugar cubes as templates, we demonstrate that 3D fabricated porous structures can become colonized by engineered bacteria and can be functionalized with highly photoreactive minerals, thereby enabling co-localization of the photocatalytic units with a bacteria-based hydrogenase reaction for a successful semi-solid artificial photosynthesis system for hydrogen evolution. Our study thus highlights the power of coupling genetically engineered proteins and polysaccharides with biofabrication techniques to generate hierarchically organized mineralized porous structures inspired by nature.

[Perinatal outcomes on mortality and influencing factors among HIV-infected mothers in Sichuan province]

Objective: To explore the influencing factors on perinatal mortality of pregnant women with HIV infection to reduce the mother-to-child transmission in Sichuan province. Methods: In this study, 4 786 perinatal infants of the HIV-infected pregnant women were included. Related data on perinatal epidemiology was reported by all the 183 medical and health care institutions where the HIV prevention of mother-to-child transmission program was initiated in 2005-2016. Univariate χ(2) test and multivariate logistic regression methods were used to analyze the perinatal mortality outcomes and influencing factors. Results: The overall perinatal mortality rate was 25.7‰ (123/4 786) among HIV-infected pregnant women, with annual downwarding trend (trend χ(2)=32.220, P=0.000). Perinatal mortality rate appeared the highest (χ(2)=4.130, P=0.042), with more fetal deaths and stillbirths and less early neonatal death within 7 days in Liangshan county (χ(2)=29.626, P=0.000). Results from the multivariate logistic regression analysis showed that fewer pregnant numbers would contribute to the, lower perinatal mortality rate (1-2 pregnancies OR=0.417, 95%CI: 0.184-0.943; 3-4 pregnancies OR=0.447, 95%CI: 0.223-0.895). Perinatal deaths were more likely to be prevented if LPV/r protease inhibitor-based triple antiviral therapy was provided (OR=0.530, 95%CI: 0.285- 0.986) or delivery was taken place in the hospital (hospital of municipal-level and above OR=0.222, 95%CI:0.098-0.499; county-level hospital OR=0.282, 95%CI: 0.166-0.480; township-level hospital OR=0.134, 95%CI: 0.031-0.586) among HIV-infected pregnant women. However, premature delivery or neonatal asphyxia would increase the risk of perinatal mortality (premature delivery OR=8.285, 95%CI: 5.073-13.533; neonatal asphyxia OR=9.624, 95%CI: 4.625-20.028). Conclusions: The perinatal mortality rate of HIV-infected pregnant women appeared significantly higher than that in the province or the whole country. Strategies involving LPV/r-based triple antiviral therapy, promotion of hospital delivery, reducing the incidence rates of premature deliveries and neonatal asphyxia, should be strengthened.

[HIV positive rate from different detection methods in medical institutions in China: a Meta analysis]

Objective: To analyze the HIV positive detection rate from different detection channels in Chinese medical institutions. Methods: A Meta-analysis was conducted. First of all, the literature on HIV testing of medical institutions in China was systematically searched on China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, VIP Information Chinese journal Service platform and PubMed. Secondly, a self-made information table was used to collect the basic information, HIV positive number and test number of the literature. Finally, R 4.0.2 software was used to calculate the pooled HIV detection rate and 95%CI of the whole population, detection approaches subgroups and regions subgroups, and then the forest map was drawn. Funnel plot was used to analyze publication bias. Results: A total of 45 studies which covered 22 provinces. Meta analysis showed that the pooled HIV positive rate was 0.82‰ (95%CI: 0.62‰-1.04‰). Subgroup analysis showed that the HIV positive rate of STD outpatient was the highest (3.01‰ (95%CI: 1.76‰-4.58‰), followed by other patients (1.43‰ (95%CI: 1.00‰-1.93‰)). The HIV positive rate of western China was the highest (1.14‰ (95%CI: 0.72‰-1.63‰)). The HIV positive rate in 2008-2017 was higher than in 2000-2007. The Egger test indicated no publication bias (t=-0.737, P=0.465). Conclusion: The HIV positive detection rate of patients in medical institutions in China was at a low level, but the positive rate of patients in STD clinics was relatively high. Therefore, the HIV testing should be further expanded in this population. Secondly, HIV screening should be strengthened for other patients.

Comparison of trans-catheter closure of paravalvular leak versus surgical approach-outcomes and cost analysis

Background

The outcomes and costs of trans-catheter closure (TC) of paravalvular leak (PVL) compared with surgical closure (SC) are rarely described.

Purpose

The aim of the study was to assess the outcomes and hospital costs of patients who underwent TC or SC of PVL in our center.

Methods

Patients who underwent TC and SC of PVL between Jan. 2016 and Dec. 2019 were enrolled. Baseline characteristics, procedural, in-hospital and mid-term outcomes and hospital costs were compared.

Results

A total of 141 patients were studied (TC, n=65 and SC, n=76). The patients were elder in TC group (56.8±12.8 years vs. 50.1±12.8 years, p=0.002). Technical success was higher in SC group (83.1% vs. 98.7%, p<0.001). Procedure room time (93±38 min vs. 395±132 min, p<0.001), intensive care unit time (0 h vs. 25 h, p<0.001), length of stay from hospitalization to discharge (7 days vs. 21 days, p<0.001) and costs (¥45090±19343 vs. ¥164165±94300, p<0.001) were significantly less in TC group. After risk adjustment, there was no significant differences between in 30 days survival between TC group and SC group. However, the residual PVLs were less in SC group (43.1% vs. 12.0%, p=0.012). At a median follow-up of 21 months, there was a trend towards reduce all-cause death following TC versus SC (OR=0.054, 95% CI: 0.070 to 0.445, p=0.007).

Conclusions

SC for PVL is associated with higher technical rates and less residual shunt. But, the shorter length of stay and lower resources use with TC group significantly reduce hospital costs. In addition, TC achieve a better mid-term results in survival.

Funding Acknowledgement

Type of funding source: None

Global longitudinal diastolic strain rate as a novel marker for predicting adverse outcomes in hypertrophic cardiomyopathy by cardiac magnetic resonance tissue tracking

AIM

To examine the prognostic value of global peak diastolic strain rate (PDSR) derived from cardiac magnetic resonance (CMR) tissue tracking (CMR-TT) in predicting adverse outcomes in hypertrophic cardiomyopathy (HCM) patients.

MATERIALS AND METHODS

A total of 98 patients diagnosed with HCM (44 patients had left ventricle [LV] outflow tract obstruction [LVOTO] and 54 patients did not) were enrolled and followed for the specified endpoint. LV global myocardial mechanics was assessed in all participants using CMR-TT at study entry.

RESULTS

Compared with the non-obstructive subgroup, the obstructive subgroup demonstrated deteriorated magnitude of LV global radial, circumferential, and longitudinal PDSR (all p<0.05). After a mean follow-up period of 4.5 years, 24 patients reached an endpoint before the end of the study. Furthermore, when using the specified cut-off value (0.33 1/s) of longitudinal PDSR, the Kaplan-Meier curve demonstrated that patients with lower longitudinal PDSR had a significantly lower freedom from major adverse cardiovascular events (MACE) compared with their counterparts in the non-obstructive, obstructive, and overall cohorts (all log-rank p<0.05). Multivariable analysis showed that longitudinal PDSR remained the strongest predictor of outcome after adjusting for baseline and CMR variables (hazard ratio, 2.65; 95% confidence interval, 2.21-11.44; p<0.05).

CONCLUSION

CMR-TT-derived longitudinal PDSR is probably considered a novel and easy-to-perform marker for predicting adverse outcomes in HCM patients, which is beneficial to risk stratification. Further confirmatory studies are needed.

Virus Disinfection from Environmental Water Sources Using Living Engineered Biofilm Materials

Waterborne viruses frequently cause disease outbreaks and existing strategies to remove such viral pathogens often involve harsh or energy-consuming water treatment processes. Here, a simple, efficient, and environmentally friendly approach is reported to achieve highly selective disinfection of specific viruses with living engineered biofilm materials. As a proof-of-concept, Escherichia coli biofilm matrix protein CsgA was initially genetically fused with the influenza-virus-binding peptide (C5). The resultant engineered living biofilms could correspondingly capture virus particles directly from aqueous solutions, disinfecting samples to a level below the limit-of-detection for a qPCR-based detection assay. By exploiting the surface-adherence properties of biofilms, it is further shown that polypropylene filler materials colonized by the CsgA-C5 biofilms can be utilized to disinfect river water samples with influenza titers as high as 1 × 107 PFU L-1. Additionally, a suicide gene circuit is designed and applied in the engineered strain that strictly limits the growth of bacterial, therefore providing a viable route to reduce potential risks confronted with the use of genetically modified organisms. The study thus illustrates that engineered biofilms can be harvested for the disinfection of pathogens from environmental water samples in a controlled manner and highlights the unique biology-only properties of living substances for material applications.

[A multicenter randomized prospective study of concurrent chemoradiation with 60 Gy versus 50 Gy for inoperable esophageal squamous cell carcinoma]

Objective: To determine whether 60 Gy is superior to standard 50 Gy for definitive concurrent chemoradiation(CCRT) in esophageal squamous cell carcinoma (ESCC) using modern radiation technology in a phase Ⅲ prospective randomized trial. Methods: From April 2013 to May 2017, 331 patients from 22 hospitals who were pathologically confirmed with stage ⅢA-ⅣA ESCC were randomized to 60 Gy or 50 Gy with random number table. Total of 305 patients were analyzed, including 152 in 60 Gy group and 153 in 50 Gy group. The median age was 63 years, 242(79.3%) males and 63(20.7%) females. The median length of primary tumor was 5.6 cm. The clinical characteristics between two groups were comparable. All patients were delivered 2 Gy per fraction, 5 fractions per week. Concurrent weekly chemotherapy with docetaxel (25 mg/m(2)) and cisplatin (25 mg/m(2)) and 2 cycles consolidation chemotherapy with docetaxel (70 mg/m(2)) and cisplatin (25 mg/m(2), d1-3) were administrated. The primary endpoint was local/regional progression-free survival (LRPFS). The data were compared with Pearson chi-square test or Fisher's exact test. Results: At a median follow-up of 27.3 months, the disease progression rate was 37.5% (57/152), 43.8% (67/153) in the high and standard-dose group, respectively (χ(2)=1.251, P=0.263). The 1, 2, 3-year LRPFS rate was 75.4%, 56.8%, 52.1% and 74.2%, 58.4%, 50.1%, respectively (HR: 0.95, 95%CI: 0.69-1.31, P=0.761). The 1, 2, 3-year overall survival rate was 84.1%, 64.8%, 54.1% and 85.4%, 62.9%, 54.0%, respectively (HR: 0.98, 95%CI: 0.71-1.38, P=0.927). The 1, 2, 3-year progression-free survival rate was 70.8%, 54.2%, 48.5% and 65.5%, 51.9%, 45.1%, respectively (HR: 0.93, 95%CI: 0.68-1.26, P=0.621). The incidence rates in toxicities between the two groups were similar except for higher rate of severe pneumonitis in high dose group (χ(2)=11.596, P=0.021). Conclusions: The efficacy in disease control is similar between 60 Gy and 50 Gy using modern radiation technology concurrent with chemotherapy for ESCC. The 50 Gy should be recommended as the regular radiation dose with CCRT for ESCC.

The relationship between regulatory T cells and radiation therapy

Radiation therapy (RT) is an effective treatment for cancer. Approximately, 70% of cancer patients receive RT in China. The immune-modulating effect of radiation therapy have gained considerable interest in recent years and there have been multiple reports of synergy between radiation and immunotherapy. Regulatory T cells (Tregs) are a group of T cell subsets with immunosuppressive function, which is correlated with cancer. Tregs are involved in the pathogenesis, development, treatment and prognosis of tumors by cell-cell contact, cytokines, and cell metabolism. Based on the immunological characteristics of Tregs, this article reviews the interaction between RT and immune molecules, aiming to provide new ideas for RT combined with immunotherapy.

Patterned Amyloid Materials Integrating Robustness and Genetically Programmable Functionality

The precise manipulation, localization, and assembly of biological and bioinspired molecules into organized structures have greatly promoted material science and bionanotechnology. Further technological innovation calls for new patternable soft materials with the long-sought qualities of environmental tolerance and functional flexibility. Here, we report a patterned amyloid material (PAM) platform for producing hierarchically ordered structures that integrate these material attributes. This platform, combining soft lithography with generic amyloid monomer inks (consisting of genetically engineered biofilm proteins dissolved in hexafluoroisopropanol), along with methanol-assisted curing, enables the spatially controlled deposition and in situ reassembly of amyloid monomers. The resulting patterned structures exhibit spectacular chemical and thermal stability and mechanical robustness under harsh conditions. The PAMs can be programmed for a vast array of multilevel functionalities, including anchoring nanoparticles, enabling diverse fluorescent protein arrays, and serving as self-supporting porous sheets for cellular growth. This PAM platform will not only drive innovation in biomanufacturing but also broaden the applications of patterned soft architectures in optics, electronics, biocatalysis, analytical regents, cell engineering, medicine, and other areas.

Correlation between gene polymorphism and opioid efficacy in patients with gastric or intestinal cancer

OBJECTIVE

To explore the correlation between gene polymorphism and opioid efficacy in patients with gastric or intestinal cancer.

PATIENTS AND METHODS

Fifty-nine patients who underwent laparoscopic surgery for gastric or intestinal cancer under general anesthesia were included and randomly divided into oxycodone (n=30) and sufentanil groups (n=29) by reproducible random number generation method. Single nucleotide polymorphisms (SNPs) of four alleles: μ-opioid receptor gene OPRM1 A118G, cytochrome P450 (CPY450) enzyme system: CPY3A4*1G, CYP3A5*3, and CYP2D6*10 were detected by PCR-pyrosequencing. Patients in sufentanil group received intravenous sufentanil injection during anesthesia induction, intraoperative maintenance, and postoperative analgesia, while those in oxycodone group received oxycodone. Patients' postoperative VAS score, opioid use, and prevalence of adverse reactions were recorded.

RESULTS

The genotype distribution of OPRM1 A118G, CYP3A4*1G, CYP3A5*3, and CYP2D6*10 in Chinese gastric cancer/intestinal cancer patients accorded with the Hardy-Weinberg law (p>0.05). OPRM1 A118G polymorphism correlated with postoperative VAS score and medication dosage, in oxycodone group (p<0.05), while it didn't with those of sufentanil group. The VAS scores in GG group were higher than that in AA group and AG group at T6-T9, (p<0.05); the postoperative pain remedies times in GG group were more than that in the AA and AG groups (p=0.002). CYP3A4*1G polymorphism related to postoperative VAS score, medication dosage and prevalence of adverse reactions in sufentanil group (p<0.05), while it didn't with those of oxycodone group (p>0.05). The total intraoperative medication in AA group was less than that in GG and GA groups (p<0.01), with a higher prevalence of respiratory depression (p=0.01). Nor was there any correlation of CYP3A5*3 and CYP2D6*10 polymorphisms with the efficacy, postoperative VAS score, pain remedies times, postoperative 24 h medication dosage, or prevalence of adverse reactions in oxycodone and sufentanil groups.

CONCLUSIONS

Gene polymorphism affects the efficacy and adverse reactions of opioids in patients undergoing laparoscopic gastric or intestinal cancer surgery.

Immobilization of functional nano-objects in living engineered bacterial biofilms for catalytic applications

Nanoscale objects feature very large surface-area-to-volume ratios and are now understood as powerful tools for catalysis, but their nature as nanomaterials brings challenges including toxicity and nanomaterial pollution. Immobilization is considered a feasible strategy for addressing these limitations. Here, as a proof-of-concept for the immobilization of nanoscale catalysts in the extracellular matrix of bacterial biofilms, we genetically engineered amyloid monomers of the Escherichia coli curli nanofiber system that are secreted and can self-assemble and anchor nano-objects in a spatially precise manner. We demonstrated three scalable, tunable and reusable catalysis systems: biofilm-anchored gold nanoparticles to reduce nitro aromatic compounds such as the pollutant p-nitrophenol, biofilm-anchored hybrid Cd_0.9Zn_0.1S quantum dots and gold nanoparticles to degrade organic dyes and biofilm-anchored CdSeS@ZnS quantum dots in a semi-artificial photosynthesis system for hydrogen production. Our work demonstrates how the ability of biofilms to grow in scalable and complex spatial arrangements can be exploited for catalytic applications and clearly illustrates the design utility of segregating high-energy nano-objects from injury-prone cellular components by engineering anchoring points in an extracellular matrix.

Modular genetic design of multi-domain functional amyloids: insights into self-assembly and functional properties

Engineering functional amyloids through a modular genetic strategy represents new opportunities for creating multifunctional molecular materials with tailored structures and performance. Despite important advances, how fusion modules affect the self-assembly and functional properties of amyloids remains elusive. Here, using Escherichia coli curli as a model system, we systematically studied the effect of flanking domains on the structures, assembly kinetics and functions of amyloids. The designed amyloids were composed of E. coli biofilm protein CsgA (as amyloidogenic cores) and one or two flanking domains, consisting of chitin-binding domains (CBDs) from Bacillus circulans chitinase, and/or mussel foot proteins (Mfps). Incorporation of fusion domains did not disrupt the typical β-sheet structures, but indeed affected assembly rate, morphology, and stiffness of resultant fibrils. Consequently, the CsgA-fusion fibrils, particularly those containing three domains, were much shorter than the CsgA-only fibrils. Furthermore, the stiffness of the resultant fibrils was heavily affected by the structural feature of fusion domains, with β-sheet-containing domains tending to increase the Young's modulus while random coil domains decreasing the Young's modulus. In addition, fibrils containing CBD domains showed higher chitin-binding activity compared to their CBD-free counterparts. The CBD-CsgA-Mfp3 construct exhibited significantly lower binding activity than Mfp5-CsgA-CBD due to inappropriate folding of the CBD domain in the former construct, in agreement with results based upon molecular dynamics modeling. Our study provides new insights into the assembly and functional properties of designer amyloid proteins with increasing complex domain structures and lays the foundation for the future design of functional amyloid-based structures and molecular materials.

Effects of dietary energy and lipase levels on nutrient digestibility, digestive physiology and noxious gas emission in weaning pigs

Objective

This study was conducted to evaluate the effect of dietary energy and lipase supplementation on growth performance, nutrient digestibility, serum profiles, intestinal morphology, small intestinal digestive enzyme activities, biochemical index of intestinal development and noxious gas emission in weaning pigs.

Methods

A total of 240 weaning pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 7.3±0.12 kg were used in this 28-d experiment. Weaning pigs were randomly allocated to 4 dietary treatments in a 2×2 factorial arrangement with 2 levels of energy (net energy = 2,470 kcal/kg for low energy diet and 2,545 kcal/kg for basal diet) and 2 levels of lipase (0 and 1.5 U/g of lipase) according to BW and sex. There were 6 replications (pens) per treatment and 10 pigs per pen (5 barrows and 5 gilts).

Results

Weaning pigs fed the low energy diet had lower (p<0.05) gain-to-feed ratio (G:F) throughout the experiment, apparent digestibility of dry matter, nitrogen, ether extract, and gross energy during d 0 to 14, average daily gain during d 15 to 28, lipase activity in duodenum and ileum and protein/DNA in jejunum (p<0.05), respectively. Lipase supplementation had no effect on growth performance but affected apparent nutrient digestibility (p<0.05) on d 14 and enhanced lipase activity in the duodenum and ileum and protease activity in duodenum and jejunum of pigs (p<0.05) fed the low energy diet. Lipase reduced serum low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG), NH₃ production (p<0.05) from the feces.

Conclusion

The low energy diet decreased G:F throughout the experiment and nutrient digestibility during d 0 to 14 as well as lipase activity in duodenum and ileum. Lipase supplementation increased nutrient digestibility during d 0 to 14 and exerted beneficial effects on lipase activity in duodenum and ileum as well as protease activity in duodenum and jejunum, while reduced serum LDL-C, TG and fecal NH₃.

Programming Cells for Dynamic Assembly of Inorganic Nano-Objects with Spatiotemporal Control

Programming living cells to organize inorganic nano-objects (NOs) in a spatiotemporally precise fashion would advance new techniques for creating ordered ensembles of NOs and new bio-abiotic hybrid materials with emerging functionalities. Bacterial cells often grow in cellular communities called biofilms. Here, a strategy is reported for programming dynamic biofilm formation for the synchronized assembly of discrete NOs or hetero-nanostructures on diverse interfaces in a dynamic, scalable, and hierarchical fashion. By engineering Escherichia coli to sense blue light and respond by producing biofilm curli fibers, biofilm formation is spatially controlled and the patterned NOs' assembly is simultaneously achieved. Diverse and complex fluorescent quantum dot patterns with a minimum patterning resolution of 100 µm are demonstrated. By temporally controlling the sequential addition of NOs into the culture, multilayered heterostructured thin films are fabricated through autonomous layer-by-layer assembly. It is demonstrated that biologically dynamic self-assembly can be used to advance a new repertoire of nanotechnologies and materials with increasing complexity that would be otherwise challenging to produce.

Diverse Supramolecular Nanofiber Networks Assembled by Functional Low-Complexity Domains

Self-assembling supramolecular nanofibers, common in the natural world, are of fundamental interest and technical importance to both nanotechnology and materials science. Despite important advances, synthetic nanofibers still lack the structural and functional diversity of biological molecules, and the controlled assembly of one type of molecule into a variety of fibrous structures with wide-ranging functional attributes remains challenging. Here, we harness the low-complexity (LC) sequence domain of fused in sarcoma (FUS) protein, an essential cellular nuclear protein with slow kinetics of amyloid fiber assembly, to construct random copolymer-like, multiblock, and self-sorted supramolecular fibrous networks with distinct structural features and fluorescent functionalities. We demonstrate the utilities of these networks in the templated, spatially controlled assembly of ligand-decorated gold nanoparticles, quantum dots, nanorods, DNA origami, and hybrid structures. Owing to the distinguishable nanoarchitectures of these nanofibers, this assembly is structure-dependent. By coupling a modular genetic strategy with kinetically controlled complex supramolecular self-assembly, we demonstrate that a single type of protein molecule can be used to engineer diverse one-dimensional supramolecular nanostructures with distinct functionalities.

Multiple ATP-binding cassette transporters are involved in insecticide resistance in the small brown planthopper, Laodelphax striatellus

ATP-binding cassette (ABC) transporters are membrane-bound proteins involved in the movement of various substrates, including drugs and insecticides, across the lipid membrane. Demonstration of the role of human ABC transporters in multidrug resistance has led to speculation that they might be an important mechanism controlling the fate of insecticides in insects. However, the role of ABC transporters in insects remains largely unknown. The small brown planthopper, Laodelphax striatellus Fallén, has developed resistance to most of the insecticides used for its control. Our goals were to identify the ABC transporters in La. striatellus and to examine their involvement in resistance mechanisms, using related strains resistant to chlorpyrifos, deltamethrin and imidacloprid, compared with the susceptible strain. Based on the transcriptome of La. striatellus, 40 full-length ABC transporters belonging to the ABCA-ABCH subfamilies were identified. Quantitative PCR revealed that over 20% of genes were significantly up-regulated in different resistant strains, and eight genes from the ABCB/C/D/G subfamilies were up-regulated in all three resistant strains, compared with the susceptible strain. Furthermore, synergism studies showed verapamil significantly enhanced insecticide toxicity in various resistant strains but not in the susceptible strain. These results suggest that ABC transporters might be involved in resistance to multiple insecticides in La. striatellus.

Toward Determining ATPase Mechanism in ABC Transporters: Development of the Reaction Path-Force Matching QM/MM Method

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are ubiquitous ATP-dependent membrane proteins involved in translocations of a wide variety of substrates across cellular membranes. To understand the chemomechanical coupling mechanism as well as functional asymmetry in these systems, a quantitative description of how ABC transporters hydrolyze ATP is needed. Complementary to experimental approaches, computer simulations based on combined quantum mechanical and molecular mechanical (QM/MM) potentials have provided new insights into the catalytic mechanism in ABC transporters. Quantitatively reliable determination of the free energy requirement for enzymatic ATP hydrolysis, however, requires substantial statistical sampling on QM/MM potential. A case study shows that brute force sampling of ab initio QM/MM (AI/MM) potential energy surfaces is computationally impractical for enzyme simulations of ABC transporters. On the other hand, existing semiempirical QM/MM (SE/MM) methods, although affordable for free energy sampling, are unreliable for studying ATP hydrolysis. To close this gap, a multiscale QM/MM approach named reaction path-force matching (RP-FM) has been developed. In RP-FM, specific reaction parameters for a selected SE method are optimized against AI reference data along reaction paths by employing the force matching technique. The feasibility of the method is demonstrated for a proton transfer reaction in the gas phase and in solution. The RP-FM method may offer a general tool for simulating complex enzyme systems such as ABC transporters.

Achievement of linear response for competitive bioaffinity assays of ligands: criteria of optimized interaction systems

For a linear response, an optimized competitive bioaffinity assay of a ligand requiresC_RT> 3 ×C_PT,C_PT> 50 ×K_dR, andK_dR> 260 ×K_dX(C_RTandC_PTare concentrations of the probe and protein whileK_dXandK_dRareK_dfor the ligand and probe, respectively).

¹H-MRS before and after resuscitation following selective cerebral ultra-profound hypothermic blood flow occlusion in monkeys

We investigated the effect of selective cerebral ultra-profound hypothermic blood flow occlusion on brain tissue and cell metabolism to ascertain the efficacy and safety of selective deep hypothermic technologies using proton magnetic resonance spectroscopy ((1)H-MRS). The bilateral carotid artery was blocked at room temperature for 10 min. Other neck vessels were then blocked through cold perfusion of the internal carotid artery and reflux of the ipsilateral jugular vein. Thus, selective cerebral extracorporeal circulation was established. Brain temperature was reduced to 15.1° ± 0.9°C. After 60 min, cerebral blood flow recovered naturally. Routine magnetic resonance imaging (MRI), diffusion-weighted imaging (DWI), and (1)H-MRS examination of the bilateral frontal cortex and basal ganglia were performed prior to surgery and 4, 24, 72 h, 21 days after recovery. The formants and areas under the curve (AUC) of N-acetyl aspartate (NAA), choline (Cho), creatine/phosphocreatine (Cr/Cr2) were analyzed using 1H-MRS. The pre- and postoperative AUC of NAA and Cho at different time points were compared. Conventional MRI and DWI showed no abnormal signal changes in the brain parenchyma or right basal ganglia before and after surgery (P > 0.05). There was no significant difference in the ratio between NAA/(Cr+Cr2) and Cho/(Cr+Cr2) before and after surgery in the bilateral basal ganglia and frontoparietal regions of the cortex (P > 0.05). Quantitative (1)H-MRS showed that selective deep cerebral hypothermia significantly improved the brain's tolerance to ischemia and hypoxia. Our results could provide a better understanding of the efficacy and safety of selective deep hypothermia and blood flow occlusion.

Changes in hippocampal ultrastructure and vimentin expression in rhesus monkeys following selective deep hypothermia and blood occlusion

Previous studies have shown that selective cerebral profound hypothermia combined with antegrade cerebral perfusion can improve resistance to cerebral hypoxia-ischemia in monkeys. The aim of this study was to observe the effect of selective cerebral profound hypothermia on the ultrastructure and vimentin expression in monkey hippocampi after severe cerebral ischemia. Eight healthy adult rhesus monkeys were randomly divided into two groups: profound hypothermia (N = 5) and normothermia (N = 3). Monkeys in the profound hypothermia group underwent bilateral carotid artery and jugular vein occlusion for 10 minutes at room temperature. Ringer's solution at 4°C was then perfused through the right internal carotid artery and out of the right jugular vein, maintaining the brain temperature below 18°C. Sixty minutes later, cerebral blood flow was restored. The normothermia group underwent all procedures with the exception that the Ringer's solution was 37°C during perfusion. All animals in the profound hypothermia group were successfully resuscitated. No significant abnormalities of hippocampal morphology or ultrastructure were observed. In contrast, no monkeys were alive after perfusion in the normothermia group and they had abnormal hippocampal morphology and ultrastructure to different extents. Vimentin expression in the hippocampus was significantly lower in the profound hypothermia group (47.88% ± 1.66) than the normothermia group (79.51% ± 1.00; P < 0.01). We conclude that selective cerebral profound hypothermia following 10-min occlusion of the bilateral common carotid arteries was able to downregulate vimentin expression in the hippocampus and protect it from severe cerebral ischemia.

Facile quantitative comparison of specific activities of fusion-tagged enzyme/mutants in cell lysates via prediction of their maximum adsorption by anti-tag antibody immobilized in microplate wells

Maximum activities of 6His-tagged enzyme/mutants from lysates adsorbed on immobilized anti-tag antibody were predicted as specific activities for comparison.

MicroRNA-145 inhibits the growth, invasion, metastasis and angiogenesis of neuroblastoma cells through targeting hypoxia-inducible factor 2 alpha

Recent evidence shows that hypoxia-inducible factor 2 alpha (HIF-2α) may have critical roles in the growth and progression of neuroblastoma (NB) under non-hypoxic conditions. However, the underlying mechanisms and clinical potentials of normoxic HIF-2α expression in NB still remain largely unknown. In this study, HIF-2α immunostaining was identified in 26/42 NB tissues, which was correlated with clinicopathological features. In subtotal 20 NB cases, microRNA-145 (miR-145) was downregulated and inversely correlated with HIF-2α expression. Bioinformatics analysis revealed a putative miR-145 binding site in the 3'-untranslated region (3'-UTR) of HIF-2α messenger RNA (mRNA). Overexpression or knockdown of miR-145 responsively altered both the mRNA and protein levels of HIF-2α and its downstream genes, cyclin D1, matrix metalloproteinase 14 and vascular endothelial growth factor, in normoxically cultured NB cell lines SH-SY5Y and SK-N-SH. In a luciferase reporter system, miR-145 downregulated the luciferase activity of HIF-2α 3'-UTR, and these effects were abolished by a mutation in the putative miR-145-binding site. Overexpression of miR-145 suppressed the growth, invasion, metastasis and angiogenesis of SH-SY5Y and SK-N-SH cells in vitro and in vivo, while restoration of HIF-2α expression rescued the tumor cells from miR-145-mediated defects in these biological features. Furthermore, anti-miR-145 inhibitor rescued the HIF-2α knockdown-mediated repression on the growth, migration, invasion and angiogenesis of NB cells. These data indicate that miR-145 suppresses HIF-2α expression via the binding site in the 3'-UTR under normoxic conditions, thus inhibiting the aggressiveness and angiogenesis of NB.

BLyS expression and JNK activation may form a feedback loop to promote survival and proliferation of multiple myeloma cells

B-Lymphocyte stimulator (BLyS), a member of tumor necrosis factor superfamily, is a potent co-activator of B cells in vitro, and in vivo induces B cell proliferation and immunoglobulin secretion. Multiple myeloma (MM) is an incurable malignancy of terminally differentiated B cells (plasma cells). Previous studies have well ascertained that BLyS plays an important contributory role in the pathogenesis and propagation of multiple myeloma by virtue of its ability to promote B cell survival, expansion, and differentiation. However, the intracellular signaling of BLyS in human MM cells remains undefined. This study was designed to see whether there was interaction between MAPK signaling pathway and BLyS expression. It was found that the active protein p-JNK was expressed in KM3, U266 and PBMCs of MM patients, and that the expression of BLyS could be changed by JNK pathway activator and inhibitor. In addition, recombinant BLyS activated JNK pathway, while BLyS siRNA treatment inhibited the activation of JNK pathway. The level of BLyS expression and the activation of JNK pathway were positively correlated. These findings suggest that JNK activation and BLyS expression in MM cells may form a positive feedback loop that promotes the survival and proliferation of MM cells, and these may shed some light on the pathogenesis and treatment of MM.