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Metallothioneins (MTs) belong to a conserved low-molecular-weight protein family that participates in heavy metal binding and detoxification. EcMT-1 was amplified by PCR from genomic DNA of Exopalaenon carinicauda. It contained a 180 bp open reading frame and encoded 59 amino acids. A total of 18 cysteine (Cys) residues were found in the deduced amino acid sequence, which was consistent with the Cys-rich characteristics of MTs. EcMT-1 was mainly expressed in hepatopancreas, followed by stomach and gill. The expression profiles of EcMT-1 indicated that EcMT-1 was significantly increased at 24, 48 h and 12, 24, and 48 h under the treatment of 2.5 μmol/L CdCl 2 and 50 μmol/L CuSO 4 . The expression of EcMT-1 at gastrula stage was very low; it was detectable until nauplius stage, and the highest expression level appeared in the postlarvae stage., (Copyright © 2022. Published by Elsevier Ltd.)

NK group 2, member D (NKG2D) is one of the most critical activating receptors expressed by natural killer (NK) cells. There is growing evidence that acute myeloid leukemia (AML) cells may evade NK cell-mediated cell lysis by expressing low or no ligands for NKG2D (NKG2D-Ls). We hypothesized that CCAAT/enhancer-binding protein α (C/EBPα), one of the most studied lineage-specific transcription factors in hematopoiesis, might influence the expression of NKG2D-Ls. To test this hypothesis, we first examined the endogenous expression of wild-type C/EBPα (C/EBPα-p42) in human AML cell lines and demonstrated that its expression level was highly relevant to the sensitivity of AML cells to NK cell cytotoxicity. Induction of C/EBPα-p42 in the low endogenous CEBPA- expressing AML cell line increased the sensitivity to NK-induced lysis. Moreover, decreased expression of C/EBPα-p42 by RNA interference in AML cells abrogated NK-mediated cytotoxicity. We further showed that the increase in NK susceptibility caused by C/EBPα-p42 occurred through up-regulation of the NKG2D-Ls ULBP2/5/6 in AML cells. More importantly, chromatin immunoprecipitation (ChIP) coupled with high-throughput sequencing captured C/EBPα motif signatures at the enhancer regions of the ULBP 2/5/6 genes. Whilst, the AML-associated C/EBPα C-terminal mutant and N-terminal truncated mutant (C/EBPα-p30) diminished ULBP2/5/6 transcription. Finally, we identified that histone demethylase lysine-specific demethylase 1 (LSD1) inhibition can restore the expression of ULBPs via induction of CEBPA expression in AML cells, which may represent a novel therapeutic strategy for CEBPA -mutated AML. Abbreviations: C/EBPα: CCAAT/enhancer-binding protein α; TF: Transcription factor; AML: Acute myeloid leukemia; TAD: Transactivation domain; FS: Frameshift; NK: Natural killer; NKG2D: NK group 2, member D; NKG2D-Ls: Ligands for NKG2D; MHC: Major histocompatibility complex; MICA: MHC class I-related chain A; ULBP: UL16-binding protein; STAT3: Signal transducer and activator of transcription 3; LSD1: Lysine-specific demethylase 1; Ab: Antibody; PBMC: Peripheral blood mononuclear cell; PBS: Phosphate-buffered saline; CFSE: Carboxyfluorescein diacetate succinimidyl ester; PI: Propidium iodide; shRNA: Short hairpin RNA; ChIP: Chromatin immunoprecipitation; BM: Binding motif; HCNE: Highly conserved noncoding element; TSS: Transcription start site; HMA: Hypomethylating agent; AZA: Azacitidine/5-azacytidine; DAC: Decitabine/5-aza-29-deoxycytidine; 2-PCPA: Tranylcypromine; RBP: RNA-binding protein; MSI2: MUSASHI-2; HDACi: Inhibitor of histone deacetylases; VPA: Valproate; DNMTi: DNA methyl transferase inhibitor; SCLC: Small cell lung cancer., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Purpose: Studies concerning do-not-resuscitate (DNR) orders in mainland China are rather scarce. We explored the prevalence and related factors of DNR orders among in-hospital cardiac arrest (IHCA) patients at a general tertiary hospital in mainland China., Materials and Methods: We identified all IHCA patients hospital-wide between July 2019 and September 2020. Data regarding DNR status were collected from medical records. We investigated the frequency of DNR orders and explored the determinant factors of DNR establishment using logistic regression., Results: A total of 1154 IHCA patients were included, 535 (46.4%) of whom established DNR orders. The following variables were independently associated with a higher DNR rate: female (OR 1.491; 95% CI 1.130-1.965), older age (OR 1.016; 95% CI 1.008-1.024), being a local resident (OR 1.790; 95% CI 1.344-2.383), pulmonary infection (OR 1.398; 95% CI 1052-1.859), respiratory insufficiency (OR 1.356; 95% CI 1.009-1.823), shock (OR 1.735; 95% CI 1.301-2.313), acute stroke (OR 1.821; 95% CI 1.235-2.686),neurological dysfunction (OR 1.527; 95% CI 1.149-2.028) and cancer (OR 3.316; 95% CI 2.461-4.468). Counterintuitively, patients with new-onset coronary artery disease (OR 0.592; 95% CI 0.419-0.837) were less likely to create DNR orders., Conclusion: In mainland China, the DNR order signing rate is low, and the establishment of a DNR order is associated with demographics and comorbidity characteristics., Competing Interests: Declaration of Competing Interests None, (Copyright © 2021 Elsevier Inc. All rights reserved.)

The impact of meteorological factors on the transport behavior and distribution of volatile and semi-volatile organic pollutants has become an area of increasing concern. Here, we analyzed seasonal variation in climatic variables including wind, temperature, and precipitation to quantitatively assess the impact of these factors on the multimedia transport and fate of BaP in the continental region of China using a Berkeley-Trent (BETR) model. The advective rates of air exhibited an increasing trend of autumn (1.830 mol/h) < summer (1.975 mol/h) < winter (2.053 mol/h) < spring (2.405 mol/h) in association with increasing wind speed, indicating that lower atmospheric BaP concentrations are present in regions with high wind speeds and advective rates. The air-soil transport rates (0.08-45.55 mol/h) in winter were higher than in summer (0.07-32.41 mol/h), while low winter temperatures accelerate BaP accumulation in terrestrial ecosystems due to cold deposition. Cold deposition effects were more evident in northern regions than in southern regions. Further, increasing precipitation enhanced air-soil and soil-freshwater transport rates with the correlation coefficients of r = 0.445 and r = 0.598 respectively, while decreasing the air-vegetation transport rates (r = 0.475), thereby contributing to the accumulation of BaP in soils and freshwaters. In the light of the potential dispersion of BaP pollution at regional and global scales affected by these key climatic factors, this indirectly indicated the impact of future climate change on the BaP transport. Thus, flexible policy interventions should be enacted to slow future climate change., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Aims/introduction: Few people have reported whether there are sex differences in blood lipids and lipid ratios in type 2 diabetic foot (T2DF) patients in China. This study attempts to identify the contribution to sex-specific differences in blood lipids and lipid ratios in these patients., Materials and Methods: In this case-control study, we explore 306 patients with T2DF as the study group and 306 patients with type 2 diabetes mellitus as the control group. Patients were diagnosed according to the Standards of Medical Care in Diabetes-2014 (American Diabetes Association). Blood lipid and lipid ratios were determined according to the National Cholesterol Education Program Adult Treatment Panel III criteria., Results: We studied male patients with T2DF who were aged 68.00 years (18.00 years) and females who were aged 73.50 years (19.00 years); 61.76% of the patients were men. Men had higher body mass index and glycated hemoglobin levels than women. Compared with type 2 diabetes mellitus patients, T2DF patients had significant differences in total cholesterol/high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol/HDL-C and apolipoprotein (apo)B/apoA-I ratios. HDL-C, triglyceride, apoA-I and apoB/apoA-I ratio showed cardiovascular disease risk in men, whereas total cholesterol, low-density lipoprotein cholesterol, apoB, and the low-density lipoprotein cholesterol/HDL-C and total cholesterol/HDL-C ratios were better predictors in women. The apoB/apoA-I ratio odds ratio values were 2.18 (95% confidence interval 1.17-4.41) and 2.14 (95% confidence interval 1.14-4.00) in male patients with T2DF before and after adjusting for age, respectively (P < 0.05)., Conclusions: T2DF patients present sex-specific differences in their blood lipid and lipid ratios, especially in the apoB/apoA-I ratio, which could be a better indicator for cardiovascular disease risk., (© 2021 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.)

The demand for flexible, efficient, and self-powered cochlear implants applied to remedy sensorineural hearing loss caused by dysfunctional hair cells remains urgent. Herein, we report an acoustic core-shell resonance harvester for the application of artificial cochleae based on the piezo-triboelectric effect. Integrating dispersed BaTiO 3 particles as cores and porous PVDF-TrFE as shells, the acoustic harvest devices with ingenious core-shell structures exhibit outstanding piezo-triboelectric properties ( V oc = 15.24 V, DA sc = 9.22 mA/m 2 ). The acoustic harvest principle reveals that BaTiO 3 nanocores resonate with sound waves and bounce against porous PVDF-TrFE microshells, thereby generating piezo-triboelectric signals. By experimental measurement and numerical modeling, the vibration process and resonance regulation of acoustic harvest devices were intensively investigated to regulate the influential parameters. Furthermore, the acoustic harvesters exhibit admirable feasibility and sensitivity for sound recording and show potential application for artificial cochlea.

Background: The absolute number of femoral neck fractures (FNFs) is increasing; however, the prediction of traumatic femoral head necrosis remains difficult. Machine learning algorithms have the potential to be superior to traditional prediction methods for the prediction of traumatic femoral head necrosis., Objective: The aim of this study is to use machine learning to construct a model for the analysis of risk factors and prediction of osteonecrosis of the femoral head (ONFH) in patients with FNF after internal fixation., Methods: We retrospectively collected preoperative, intraoperative, and postoperative clinical data of patients with FNF in 4 hospitals in Shanghai and followed up the patients for more than 2.5 years. A total of 259 patients with 43 variables were included in the study. The data were randomly divided into a training set (181/259, 69.8%) and a validation set (78/259, 30.1%). External data (n=376) were obtained from a retrospective cohort study of patients with FNF in 3 other hospitals. Least absolute shrinkage and selection operator regression and the support vector machine algorithm were used for variable selection. Logistic regression, random forest, support vector machine, and eXtreme Gradient Boosting (XGBoost) were used to develop the model on the training set. The validation set was used to tune the model hyperparameters to determine the final prediction model, and the external data were used to compare and evaluate the model performance. We compared the accuracy, discrimination, and calibration of the models to identify the best machine learning algorithm for predicting ONFH. Shapley additive explanations and local interpretable model-agnostic explanations were used to determine the interpretability of the black box model., Results: A total of 11 variables were selected for the models. The XGBoost model performed best on the validation set and external data. The accuracy, sensitivity, and area under the receiver operating characteristic curve of the model on the validation set were 0.987, 0.929, and 0.992, respectively. The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of the model on the external data were 0.907, 0.807, 0.935, and 0.933, respectively, and the log-loss was 0.279. The calibration curve demonstrated good agreement between the predicted probability and actual risk. The interpretability of the features and individual predictions were realized using the Shapley additive explanations and local interpretable model-agnostic explanations algorithms. In addition, the XGBoost model was translated into a self-made web-based risk calculator to estimate an individual's probability of ONFH., Conclusions: Machine learning performs well in predicting ONFH after internal fixation of FNF. The 6-variable XGBoost model predicted the risk of ONFH well and had good generalization ability on the external data, which can be used for the clinical prediction of ONFH after internal fixation of FNF., (©Huan Wang, Wei Wu, Chunxia Han, Jiaqi Zheng, Xinyu Cai, Shimin Chang, Junlong Shi, Nan Xu, Zisheng Ai. Originally published in JMIR Medical Informatics (https://medinform.jmir.org), 19.11.2021.)

Introduction: We aimed to summarize the clinical characteristics of Floating-Harbor syndrome (FHS) and the effect of recombinant human growth hormone (rhGH) to increase height. Methods: The clinical manifestations, gene sequencing results, treatment, and regression of one child with FHS were reported at the Department of Pediatrics, General Hospital of Tianjin Medical University, in July 2020. PubMed was searched using the keyword "Floating-Harbor Syndrome" up to March 2021 to obtain clinical information on children with FHS for review. Results: The child, who was a male aged 6 years and 9 months, presented to the clinic with main complaints of delayed language development since childhood and a short stature for 4 years. The child's short stature, peculiar facial features, delayed language development, and delayed bone development were considered alongside genetic testing and Sanger sequencing to verify the results. A heterozygous mutation (c.7401delC; p.Ile2468Phefs * 7) was identified in exon 34 of the SRCAP gene, which was a frameshift mutation, and Sanger verification showed that neither parent had this mutation. The child was administered subcutaneous injection of rhGH (0.13 U/kg/day) and was followed up regularly. At the time of writing, the child had been treated for 6 months and was 7 years and 3 months old with a height of 106.3 cm (-3.69 SDS), which was a height increase of 6.3 cm. The patient did not complain of discomfort during treatment and presented normal laboratory tests results. Twenty-two children with FHS treated with rhGH were included in the literature review, and most of these patients demonstrated an increase in height SDS without adverse effects. Conclusion: Short stature, delayed skeletal maturation, impaired language expression, intellectual deficits, and peculiar facial features are the main clinical features of FHS. rhGH can be used as a treatment to increase height in patients with FHS, but its effectiveness and safety still need to be monitored in larger sample sizes over longer periods of time., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Bo, Jiang, Zheng and Sun.)

Emission intensity and climate change control the transport flux and fate of persistent organic pollutants (POPs) in multiple environmental compartments. This study applied a multimedia model (BETR model) to explore alternations in the spatio-temporal trends of concentrations and transport flux of benzopyrene (BaP), phenanthrene (Phe), perfluorooctane sulfonates (PFOS) and polychlorinated biphenyls (PCBs) in the Chaohu watershed, located in the lower reaches of the Yangtze River, China in response to changes in source emissions and climate. The potential historic and future risks of these pollutants also were assessed. The results suggest that current trends in concentrations and transport were similar to that of their emissions between 2005 and 2018. During the next 100 years, temporal trends and spatial patterns were not predicted to change significantly, which is consistent with climate change. Based on sensitivity and correlation analyses, climate change had significant effects on multi-media concentrations and transport fluxes of BaP, Phe, PFOS and PCBs, and rainfall intensity was the predominant controlling factor. Risk quotients (RQs) of BaP and Phe-in soil increased from 0.42 to 0.95 and 0.06 to 0.35, respectively, from 2005 to 2090, indicating potential risks. The RQs of the other examined contaminants exhibited little potential risk in soil, water, or sediment. Based on spatial patterns, it was inferred that the ecosystem around Lake Chaohu is the most at risk. The study provides insights needed for local pollution control of POPs in the Chaohu watershed. In addition, the developed approach can be applied to other watersheds world-wide., (Copyright © 2021. Published by Elsevier B.V.)

Today's widely used and rapidly updated electronic substrates are composed of petroleum-based polymers, but the resulting electronic waste (such as Dioxin, oxole, PCBs, etc.) will cause massive harm to the environment and human body. Therefore, we report an effective approach for fabricating recyclable and high-performance cellulose films as green electronic substrates by calendering. The crosslinking between CH and CHCH in cellulose modified by maleic anhydride led to the in-situ formation of a chemical crosslinking network, and hydrogen bonds acted as a sacrificial physical crosslinking network. The dual crosslinked cellulose film exhibits high strength (120.56 MPa), improved elongation (increased by 263%), and outstanding thermal stability (thermal decomposition temperature is 311 °C). Further, the film has been successfully used as a substrate for biomass sensor and realized apparent responses to changes. The scientific strategy paves the way for the large-scale fabrication of high-performance cellulose films and simultaneously promotes green electronic substrates' industrialization., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Lactic acid bacteria (LAB) are a kind of Gram-positive bacteria which can colonize in the biological gastrointestinal tract and play a variety of probiotic roles. LAB have a wide range of applications in industry, animal husbandry, planting, food safety, and medical science fields. Previous studies on LAB have typically concentrated on their effects on improving the digestion and absorption of the gastrointestinal tract, regulating the balance of the microflora, and inhibiting the production and accumulation of toxic substances. The resistance of LAB to cancer is a topic of growing interest and relevance. This paper provided a summary of bio-active substances of LAB when they act against cancer, as well as the safety of LAB in clinical cancer treatment. Moreover, this paper further discussed several possible directions for future research and the potential application of LAB as anti-cancer therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Liu, Zheng, Ou and Han.)

Metal nanostructured materials, with many excellent and unique physical and mechanical properties compared to macroscopic bulk materials, have been widely used in the fields of electronics, bioimaging, sensing, photonics, biomimetic biology, information, and energy storage. It is worthy of noting that most of these applications require the use of nanostructured metals with specific controlled properties, which are significantly dependent on a series of physical parameters of its characteristic size, geometry, composition, and structure. Therefore, research on low-cost preparation of metal nanostructures and controlling of their characteristic sizes and geometric shapes are the keys to their development in different application fields. The preparation methods, physical and chemical properties, and application progress of metallic nanostructures are reviewed, and the methods for characterizing metal nanostructures are summarized. Finally, the future development of metallic nanostructure materials is explored.

RG-I rich pectic polysaccharide is common in fruit and vegetable and possesses health benefits. However, it is removed during commercial pectin production because of poor gelling properties. Synergistic gelation can improve rheological properties of RG-I pectic polysaccharide and expand its application in functional food hydrocolloids. In the study, RG-I rich pectic polysaccharides at different degree of esterification was extracted from citrus membrane by sequential mild acidic (0.4% HCl, 28 °C) and alkaline (0.6% NaOH, 32 °C) treatment. The pectic polysaccharide from acid water (PA) composes of 41% RG-I and 44% HG with DM of 45%, while the pectic polysaccharide from basic water (PB) composed of 63% RG-I and 19% HG with DM of 15%. PA/PB blend gel under CaCO 3 -glucono-δ-lactone system showed improved rheological properties compared with pure gels. Ca-bridges connected pectin aggregates and promoted the three-dimensional structure of PA/PB blend gels, while neutral sugar side-chains prompted hydrogen bonds and strengthened gel network., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Restricted by the inherent property of low power density, acoustic energy can hardly be effectively captured by conventional piezo- or triboelectric nanogenerators for powering miniature electronics. Herein, a novel piezo-tribo hybrid nanogenerator employing nanoporous polyvinylidene fluoride (PVDF) hollow fiber and polydimethylsiloxane (PDMS) valve, which can mimic the eardrum, has been advocated for efficient acoustic harvesting. The nanoporous, hollow, and valve structure design, together with the effective combination of piezo- and triboelectricity, make the nanoporous PVDF hollow fiber and PDMS valve based acoustic harvester (PHVAH) a promising candidate for acoustic-electric conversion. With an optimal output of 105.5 V and 16.7 μA and a power density of 0.92 W m -2 under the sound stimulation of 117.6 dB and 150 Hz, it can not only recognize audio signals but also convert the sound into electrical energy to light up seven LED bulbs in series. Exhibiting excellent durability and stability, the disruptive innovation proposed here is an effective method for hunting the ubiquitous sound energy in the environment, which provides great potential and impetus for using acoustic-electric conversion to power various low-power-consumption sensors.

Arginine kinase (AK, EC 2.7.3.3) plays an important role in cells with high, fluctuating energy requirements. In invertebrates, AK is the major phosphagen kinase that modulates the energy metabolism. Here, the full-length cDNA sequence encoding arginine kinase (EcAK) was obtained from the Exopalaemon carinicauda. The complete nucleotide sequence of EcAK contained a 1068 bp open reading frame (ORF) encoding EcAK precursor of 355 amino acids. The genomic DNA fragment of EcAK with the corresponding cDNA sequence is composed of 4 exons and 3 introns. The domain architecture of the deduced EcAK protein contained an ATP-gua&#95;PtransN domain and an ATP-gua&#95;Ptrans domain. EcAK mRNA was predominantly expressed in the muscle. The expression of EcAK in the prawns challenged with Vibrio parahaemolyticus and Aeromonas hydrophila changed in a time-dependent manner. Then, EcAK was recombinantly expressed in Pichia pastoris and the purified recombinant EcAK had the same enzymatic characterization as AK from the muscle of Euphausia superba. In conclusion, EcAK may play the same biological activity in E. carinicauda as those from other crustaceans., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: This study aimed at developing a risk score predicting the probability of developing an osteonecrosis of the femoral head (ONFH) in patients with femoral neck fracture within 3 years after closed reduction internal fixation and evaluating its performance, clinical utility, and internal validity., Methods: A retrospective follow-up study of 378 newly injured femoral neck fracture patients treated with 3 partially threaded parallel cannulated screws in 3 hospitals in Shanghai from March 2013 to January 2017 was performed. The patients were divided into development (n = 284) and validation (n = 94) cohorts. The risk score was constructed by Cox regression analysis in a form of nomogram. The performance and clinical utility were illustrated by box plots, calibration plots, and decision curve analysis., Results: Eighty-three of 378 patients had developed ONFH within 3 years. Garden alignment index, time to surgery, preoperative displace, impaction, and postoperative malposition were used as predictors to construct the risk score in a form of nomogram. In the development and validation cohort, the concordance index was 0.96 and 0.94, respectively; the discrimination slope was 0.51 and 0.47, respectively. In both cohorts, the calibration slopes and intercepts were 1 and 0, respectively. The risk score was clinically useful between the risk threshold of 0% and 88%. The performance and utility in the validation data illustrated good repeatability., Conclusion: The risk score had satisfactory discrimination and calibration performance and demonstrated clinical utility with good internal validity. It managed to distinguish high-risk groups for post-traumatic ONFH., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Cellulose limited by fusibility and solubility is impossible to be directly thermoformed, of which the existing progress crucially relies on larger liquids, making it hard to achieve a direct all-green manufacture. Here, we propose an innovative strategy that the surface molecular chains of cellulose nanospheres are activated at 100 °C and intertwined under 500 MPa because of the high molecular activity on the surface of nanospheres and the reduction of activation energy after ball-milling. It is confirmed that only physical changes are involved, according to infrared spectrum. Results show that applicable mechanical properties (hardness and modulus reach 0.44 and 9.66 GPa, respectively) are successfully obtained. Simultaneously, the optimum optical performance of all-cellulose substrate reaches more than 80 % at visible light. Combined with their intrinsic properties, these cellulose-based products could be potentially utilized as biomass substrates. Therefore, our innovative strategy opens up a door for the direct thermoforming of cellulose., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Rhamnogalacturonan I (RG-I) pectin are regarded as strong galectin-3 (Gal-3) antagonist because of galactan sidechains. The present study focused on discussing the effects of more structural regions in pectin on the anti-Gal-3 activity. The water-soluble pectin (WSP) recovered from citrus canning processing water was categorized as RG-I pectin. The controlled enzymatic hydrolysis was employed to sequentially remove the α-1,5-arabinan, homogalaturonan and β-1,4-galactan in WSP. The Gal-3-binding affinity KD (kd/ka) of WSP and debranched pectins were calculated to be 0.32 μM, 0.48 μM, 0.56 μM and 1.93 μM. Moreover, based on the more sensitive cell line (MCF-7) model, the IC 30 value of WSP was lower than these of modified pectins, indicating decreased anti-Gal-3 activity. Our results suggested that the total amount of neutral sugar sidechains, the length of arabinan and cooperation between HG and RG-I played important roles in the anti-Gal-3 activity of WSP, not the Gal/Ara ratio or RG-I/HG ratio. These results provided a new insight into structure-activity relationship of citrus segment membrane RG-I as a galectin-3 antagonist and a new functional food., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2020. Published by Elsevier Ltd.)

Posttranscriptional gene regulation often involves RNA-binding proteins that modulate mRNA translation and/or stability either directly through protein-RNA interactions or indirectly by facilitating the annealing of small regulatory RNAs (sRNAs). The human pathogen Streptococcus pneumoniae D39 (pneumococcus) does not encode homologs to RNA-binding proteins known to be involved in promoting sRNA stability and function, such as Hfq or ProQ, even though it contains genes for at least 112 sRNAs. However, the pneumococcal genome contains genes for other RNA-binding proteins, including at least six S1 domain proteins: ribosomal protein S1 ( rpsA ), polynucleotide phosphorylase ( pnpA ), RNase R ( rnr ), and three proteins with unknown functions. Here, we characterize the function of one of these conserved, yet uncharacterized, S1 domain proteins, SPD&#95;1366, which we have renamed CvfD ( c onserved v irulence f actor D ), since loss of the protein results in attenuation of virulence in a murine pneumonia model. We report that deletion of cvfD impacts the expression of 144 transcripts, including the pst1 operon, encoding phosphate transport system 1 in S. pneumoniae We further show that CvfD posttranscriptionally regulates the PhoU2 master regulator of the pneumococcal dual-phosphate transport system by binding phoU2 mRNA and impacting PhoU2 translation. CvfD not only controls expression of phosphate transporter genes but also functions as a pleiotropic regulator that impacts cold sensitivity and the expression of sRNAs and genes involved in diverse cellular functions, including manganese uptake and zinc efflux. Together, our data show that CvfD exerts a broad impact on pneumococcal physiology and virulence, partly by posttranscriptional gene regulation. IMPORTANCE Recent advances have led to the identification of numerous sRNAs in the major human respiratory pathogen S. pneumoniae However, little is known about the functions of most sRNAs or RNA-binding proteins involved in RNA biology in pneumococcus. In this paper, we characterize the phenotypes and one target of the S1 domain RNA-binding protein CvfD, a homolog of general stress protein 13 identified, but not extensively characterized, in other Firmicutes species. Pneumococcal CvfD is a broadly pleiotropic regulator, whose absence results in misregulation of divalent cation homeostasis, reduced translation of the PhoU2 master regulator of phosphate uptake, altered metabolism and sRNA amounts, cold sensitivity, and attenuation of virulence. These findings underscore the critical roles of RNA biology in pneumococcal physiology and virulence., (Copyright © 2020 American Society for Microbiology.)

Traditional self-assembly methods for photonic crystals (PCs) limited by poor mechanical performance and microstructure defects make it hard to be directly applied to optical devices, whose performance strongly rely on mechanical performance and microstructure of PCs. Here, a thermoforming-etching strategy combining both traditional processing and nanofabrication is reported to develop cross-linked polystyrene microsphere-based PC bulks with outstanding mechanical performance. It illustrates scientific principles, where surface molecular chains of PS microspheres were activated and entangled with each other under thermoforming conditions (200 °C; 220 MPa), resulting in applicable mechanical strength (hardness and modulus reach 0.12 and 4.12 GPa, respectively). The optimum optical reflectivity of the PS microsphere-based (180 nm) PC bulk is 49.4% at 381 nm. Furthermore, these PC bulks have been successfully written in anti-counterfeiting and realized colorful pattern printing. The innovative method opens a new route for the rapid and simple fabrication of the nanoparticle structure which can be used as various functional devices and directly promotes the industrialization of bulk PC devices, such as optical and display devices, and so forth.

To better understanding the potential of manosonication to accelerate the extraction of RG-I pectic polysaccharides from citrus wastes, alkaline-mediated manosonication extraction (MSE) was optimized using a Box-Behnken design, and the extraction kinetics model was analyzed. The single-factor method revealed that NaOH significantly impacted on the yield and RG-I characterizations (Rha mol% and (Gal+Ara)/Rha ratio), whereas other factors were focused on influences of yields. In the developed quadratic polynomial model, the maximum extraction yield of 25.51 ± 0.81 % was obtained with sonication at 42 ℃, 40 % amplitude, and 250 kPa for 20 min. The kinetics study demonstrated that MSE facilitated the extractability, dissolution and degradation of pectin, resulting in the highest extractability of 27.83 % compared with ultrasonic extraction (22.86 %) and alkaline extraction at high (24.71 %) and low temperature (20.21 %). Rheology and thermal analyses verified the change in polymerization by MSE and the potential functional applications of the RG-I pectic polysaccharides., Competing Interests: Declaration of Competing Interest There is no conflicting interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: The Global Registry of Acute Coronary Events (GRACE) score is recommended for stratifying chest pain. However, there are six formulas used to calculate the GRACE score for different outcomes of acute coronary syndrome (ACS), including death (Dth) or composite of death and myocardial infarction (MI), while in hospital (IH), within 6 months after discharge (OH6m) or from admission to 6 months later (IH6m). We aimed to perform the first comprehensive evaluation and comparison of six GRACE models to predict 30-day major adverse cardiac events (MACEs) in patients with acute chest pain in the emergency department (ED)., Methods: Patients with acute chest pain were consecutively recruited from August 24, 2015 to September 30, 2017 from the EDs of two public hospitals in China. The 30-day MACEs included death, acute myocardial infarction (AMI), emergency revascularization, cardiac arrest and cardiogenic shock. The correlation, calibration, discrimination, reclassification and diagnostic accuracy at certain cutoff values of six GRACE models were evaluated. Comparisons with the History, ECG, Age, Risk Factors, and Troponin (HEART) and Thrombolysis in Myocardial Infarction (TIMI) scores were conducted., Results: A total of 2886 patients were analyzed, with 590 (20.4%) patients experiencing outcomes. The GRACE (IHDthMI), GRACE (IH6mDthMI), GRACE (IHDth), GRACE (IH6mDth), GRACE (OH6mDth) and GRACE (OH6mDthMI) showed positive linear correlations with the actual MACE rates (r ≥ 0.568, P < 0.001). All these models had good calibration (Hosmer-Lemeshow test, P ≥ 0.073) except GRACE (IHDthMI) (P < 0.001). The corresponding C-statistics were 0.83(0.81,0.84), 0.82(0.81,0.83), 0.75(0.73,0.76), 0.73(0.72,0.75), 0.72(0.70,0.73) and 0.70(0.68,0.71), respectively, first two of which were comparable to HEART (0.82, 0.80-0.83) and superior to TIMI (0.71, 0.69-0.73). With a sensitivity ≥95%, GRACE (IHDthMI) ≤81 and GRACE (IH6mDthMI) ≤79 identified 868(30%) and 821(28%) patients as low risk, respectively, which were significantly better than other GRACEs and HEART ≤3(22%). With a specificity ≥95%, GRACE (IHDthMI) > 186 and GRACE (IH6mDthMI) > 161 could recognize 12% and 11% patients as high risk, which were greater than other GRACEs, HEART ≥8(9%) and TIMI ≥5(8%)., Conclusions: In this Chinese setting, certain strengths of GRACE models beyond HEART and TIMI scores were still noteworthy for stratifying chest pain patients. The validation and reasonable application of appropriate GRACE models in the evaluation of undifferentiated chest pain should be recommended.

Background: Triage decisions for chest pain patients receiving usual care are based on a dynamic and comprehensive strategy performed in the physician's mind. It remains controversial whether simple, structured risk tools can surpass real, complex judgments., Hypothesis: The potentially used History, Electrocardiogram, Age, Risk factors, Troponin (HEART) score would help identify low-risk patients for discharge., Methods: Patients with acute, non-traumatic chest pain managed according to usual care were consecutively enrolled in a tertiary university hospital in China from August 24, 2015 to September 30, 2017. Major adverse cardiac events (MACE) included death, acute myocardial infarction, revascularization, and significant coronary stenosis (>50%) within 30 days. We compared the efficacy and safety of usual care and the potentially used HEART score in this population., Results: Of 2185 patients analyzed, 926 (42.4%) patients were directly discharged by usual care, whereas HEART≤3 would have identified 524 (24.0%) patients as low-risk (P < .001). The MACE rate in discharged patients was 2.2% (20/926) and would have been 5.2% (27/524) in those with HEART≤3 (P = .002). For discharged patients, the MACE rates in HEART≤3 vs HEART>3 groups were not significantly different (1.5% vs 2.7%, P = .225). Negative predictive value (NPV) was higher with usual care than with the HEART score (P = .003), but sensitivity was similar. For 340 patients with serial troponins, usual care was superior to the potentially used HEART score in regard to efficacy., Conclusions: At this institution, usual care identified many more patients for discharge than the HEART score would have without apparently different outcomes in discharged patients with lower vs higher HEART scores. The HEART score would not appear to provide helpful risk stratification., (© 2019 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Infrared light (IR) detection principles limited by poor photoresponsivity and sparse photogenerated carrier make them impossible to directly applied in flexible IR sensing field attributed to low π-π conjugation effect, thick P-N junction, and harsh band gap, of which IR self-powered electronic skin (e-skin) strongly relies on the essential property of exotic photosensitive-exciting materials, hardly any flexible organic polymer or nanocomposites. Here, an innovative IR self-powered principle is reported that outstanding piezoelectric effect of poly(vinylidene fluoride) nanofibers (PVDF NFs) is driven by microcrystals' volume expansion caused by the solid-solid phase transition of PVDF/multiwalled carbon nanotubes (MWCNTs)/highly elastic phase change polymer (HEPCP) (PMH) nanocomposites due to MWCNT's excellent IR photoabsorption and thermal conversion capabilities. A flexible IR-sensitive nanocomposite is successfully developed employing PVDF/HEPCP NFs as the framework of a three-dimensional network structure wrapped by the MWCNT/HEPCP nanocomposite. The 33, 50, and 60 wt % PMH nanocomposites are demonstrated cyclic, IR-regulated on/off piezoelectric sensitivity of 889.7, 977.6, and 493.8 mV/(mW·mm -2 ) at IR powers of 5.3 mW/mm 2 , respectively. Furthermore, IR self-powered e-skin has been developed successfully and realized an accurate IR stimulus-sensing location due to the sensitivity, which depends on the size of the sensing area. This innovative strategy provides a new route to the fundamental science and applications of flexible IR self-powered devices, such as e-skin, artificial vision, soft robots, active surveillance sensors, etc.

Dietary intake of potato starch could induce a dramatic increase in blood glucose and is positively associated with chronic metabolic diseases (type II diabetes, cardiovascular disease, etc.). Grape seed proanthocyanidins (GSP) are known to decrease starch digestion by inhibiting digestive enzymes or changing the physicochemical properties of starch. In the present study, GSP were complexed with potato starch to prepare polyphenol-starch complexes. The physiochemical properties and digestibility of complexes were investigated by in vitro digestion model, X-ray diffraction, differential scanning calorimetry, rapid visco analyzer, Fourier transform infrared spectroscopy as well as texture profile analysis. Results indicated that the peak viscosity, breakdown, trough, and setback of the complexes disappeared, replaced by a special continuous increase in paste viscosity. The complexes showed a lower final viscosity and higher thermal stability with the increasing binding amount of GSP. GSP decreased the hardness of the complexes' gel significantly. FT-IR indicated that GSP might interact with potato starch through noncovalent forces. Additionally, the complexes also showed a higher content of slowly digestible starch and resistant starch than that of the native starch. Thus, we inferred that the addition of GSP could modify the digestibility of potato starch and be an optional way to modify the starch with lower digestion.

Rhamnogalacturonan I (RG-I) pectin is composed of backbone of repeating disaccharide units →2)-α-L-Rhap-(1→4)-α-D-GalpA-(1→ and neutral sugar side-chains mainly consisting of arabinose and galactose having variable types of linkages. However, since traditional pectin extraction methods damages the RG-I structure, the characteristics and health effects of RG-I remains unclear. Recently, many studies have focused on RG-I, which is often more active than the homogalacturonan (HG) portion of pectic polysaccharides. In food products, RG-I is common to fruits and vegetables and possesses many health benefits. This timely and comprehensive review describes the many different facets of RG-I, including its dietary sources, history, metabolism and potential functionalities, all of which have been compiled to establish a platform for taking full advantage of the functional value of RG-I pectin.

The modified pectin (MP) showed the improved functional properties than the native one. The aim of present study was to develop the ultrasonic accelerated bicarbonate-hydrogen peroxide system for pectin modification to generate short fragments with advanced bioactive properties. The depolymerization effects of this system on the physicochemical properties, structural features, and bioactivity of the degraded fragments were studied systematically. The results indicated that the molecular weight of pectin was reduced drastically from 1088 kDa to 33 kDa within 50 min under an optimized condition (M H2O2 -M NaHCO3  = 1:2.5, 50 °C, and ultrasound intensity = 11.4 W/cm 3 ). The resulting fragments also showed lower degree of methoxylation and rheological viscosity. The investigation on the sample structures and active oxygen species demonstrated that the highly active O 2 - species generated from HCO 4 - of NaHCO 3 -H 2 O 2 acted preferentially on the GalA backbone in the HG region, while the RG-I region was maintained; and ultrasound enhanced the degradation efficiency via both chemical effects (increasing the transformation of free radicals) and mechanical effects (disaggregating polysaccharide clusters). The atomic force microscope (AFM) imaging directly verified the branched-chain morphology of pectin and the small-strand degradation fragments. Moreover, ultrasound and NaHCO 3 -H 2 O 2 treatment induced high galactose content in the degraded products, contributing to an improved inhibitory activity against A549 lung cancer cells, as shown by MTT assay., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: More sensitive troponin assays have the potential to better evaluate patients with suspected acute coronary syndrome (ACS). Meanwhile, they may result in avoidable diagnostic testing., Hypothesis: Our aim was to determine the clinical impact of implementing a more sensitive cardiac troponin I (cTnI) assay in patients with acute non-traumatic chest pain presenting to the emergency department (ED)., Methods: This is a pre-post cohort study. A total of 1201 consecutive patients with acute non-traumatic chest pain or equivalent ischemic symptoms suggestive of ACS were allocated to two groups according to the cTnI assay used. The outcomes included the ED length of stay (LOS), hospital admission rate, the use of procedures and the incidence of major adverse cardiac events (MACE) at 30 days., Results: The introduction of the more sensitive troponin assay shortened ED LOS (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.28-0.54) regarding patients discharged home directly, increased the hospital admission rate (OR 1.43, 95% CI 1.12-1.84), the use of echocardiography (OR 1.58, 95% CI 1.22-2.06), coronary computed tomography angiography (OR 1.78, 95% CI 1.04-3.06), coronary angiography (OR 1.53, 95% CI 1.10-2.12) and percutaneous coronary intervention (OR 2.42, 95% CI 1.58-3.70) regarding patients discharged or admitted. The incidence of MACE did not decrease significantly (OR 0.61, 95% CI 0.27-1.37)., Conclusions: The introduction of the more sensitive troponin assay appeared to result in less time spent in the ED regarding patients discharged home directly, but prompted more hospitalizations and procedures without impacting the incidence of MACE., (© 2019 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Critically ill patients with fecal incontinence are at high risk of developing incontinence-associated dermatitis (IAD). Scientific prediction and prevention of IAD are essential., Purpose: The purpose of this study was to determine the risk factors for IAD among critically ill patients with fecal incontinence. Based on this information, a predictive risk assessment model was developed to provide research evidence for IAD prevention., Methods: A prospective study was conducted from October 2016 to December 2017. Convenience sampling was used to recruit patients with fecal incontinence treated in intensive care units (ICUs) at Tianjin Medical University General Hospital in China. Trained nurses collected demographic data (age, gender, and ICU type), data related to fecal incontinence (Perineal Assessment Tool [PAT] scores, bowel movement frequency, and stool traits per the Bristol Stool Scale), and clinical data (length of ICU hospitalization, body temperature, diabetes history, hypertension history, consciousness, nutrition support, oxygen supply, number of antibiotic species, sedative use, and albumin levels) from participants and their medical records. The PAT was used to assess patient risk of developing IAD, and the Bristol Stool Scale was used to assess patient stool traits. Names were coded anonymously, and data were entered from paper-and-pencil questionnaires into a software program for statistical analysis. Univariate analysis and multivariate logistic regression were performed to identify risk factors for IAD. A predictive risk factor model was established using a receiver operating characteristic curve., Results: Among 266 critically ill patients with fecal incontinence (182 male, 84 female; mean age 64.18 ± 17.10), IAD incidence was 65.4%. The use of sedative drugs, coma status, higher PAT score, more frequent bowel movements, and loose stool were found to be independent risk factors for IAD (P <.05). The subsequent risk factor predictive model had a sensitivity and specificity of 99.4% and 96.7%, respectively, and the agreement rate was 98.1%., Conclusion: The identified risk factors and subsequent predictive model may contribute to timely identification and quantitative risk assessment of IAD among critically ill patients. Additional quantitative research could provide a scientific basis for the development of specific preventive interventions.

Background: Symptom is still indispensable for the stratification of chest pain in the emergency department. However, it is a sophisticated aggregation of several aspects of characteristics and effective combination of those variables remains deficient. We aimed to develop and validate a chest pain symptom score (CPSS) to address this issue., Hypothesis: The CPSS may help stratifying acute undifferentiated chest pain in ED., Methods: Patients with non-ST segment elevation chest pain and negative cardiac troponin (cTn) over 3 hours after symptom onset were consecutively recruited as the derivation cohort. Logistic regression analyses identified statistical predictors from all symptom aspects for 30-day acute myocardial infarction (AMI) or death. The performance of CPSS was compared with the symptom classification methods of the history variable in the history, electrocardiograph, age, risk factors, troponin (HEART) score. This new model was validated in a separated cohort of patients with negative cTn within 3 hours., Results: Seven predictors in four aspects of chest pain symptom were identified. The CPSS was an independent predictor for 30-day AMI or death (P < 0.001). In the derivation (n = 1434) and validation (n = 976) cohorts, the expected and observed event rates were well calibrated (Hosmer-Lemeshow test P > 0.30), and the c-statistics of CPSS were 0.72 and 0.73, separately, significantly better than the previous history classifications in HEART score (P < 0.001). Replacing the history variable with the CPSS improved the discrimination and risk classification of HEART score significantly (P < 0.001)., Conclusions: The effective combination of isolated variables was meaningful to make the most stratification value of symptoms. This model should be considered as part of a comprehensive strategy for chest pain triage., (© 2019 The Authors. Clinical Cardiology published by Wiley Periodicals, Inc.)

Introduction: Acute chest pain represents a major healthcare burden in emergency departments (ED) throughout the world. Among these patients, rapidly determining whether an acute coronary syndrome (ACS) is evolving remains difficult. In China, there are limited data correlating the baseline characteristics, evaluation and management of ED patients with acute chest pain and ACS-related symptoms with clinical outcomes. Nor has there been an evaluation of outcomes at different levels of hospitals. The Evaluation and Management of Patients with Acute ChesT pain in China (EMPACT) study will address this evidence gap through a regional representative prospective registry., Methods and Analysis: Twenty-two public hospitals with ED in Shandong province have been selected based on a stratified random sampling approach. A total of 10 000 patients with acute chest pain or suspected ACS presenting to the ED will be consecutively enrolled from January 2016 to September 2017. Episodes of care will be evaluated for key performance measures such as the time to first ECG, receipt of troponin testing, receipt of reperfusion therapy for ST segment elevation ACS and provision of angiography for troponin-positive patients. All patients will be assessed for the composite endpoint of adjudicated major adverse cardiac events in 30 days after presentation, including death from all causes, non-fatal myocardial infarction, urgent revascularisation, stroke, cardiac arrest and cardiogenic shock. The secondary outcomes include revisit to ED and rehospitalisation within 30 days., Ethics and Dissemination: Ethics approval was obtained at all participating centres. The registry is the first attempt to comprehensively evaluate the current emergency care of acute chest pain from a regional representative sample in China. Findings will allow new opportunities to facilitate the clinical quality improvements and ultimately reduce the mortality in patients with acute chest pain and suspected ACS., Trial Registration Number: NCT02536677; Pre-results., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Suppressor mutations were isolated that obviate the requirement for essential PBP2b in peripheral elongation of peptidoglycan from the midcells of dividing Streptococcus pneumoniae D39 background cells. One suppressor was in a gene encoding a single KH-domain protein (KhpA). ΔkhpA suppresses deletions in most, but not all (mltG), genes involved in peripheral PG synthesis and in the gpsB regulatory gene. ΔkhpA mutations reduce growth rate, decrease cell size, minimally affect shape and induce expression of the WalRK cell-wall stress regulon. Reciprocal co-immunoprecipitations show that KhpA forms a complex in cells with another KH-domain protein (KhpB/JAG/EloR). ΔkhpA and ΔkhpB mutants phenocopy each other exactly, consistent with a direct interaction. RNA-immunoprecipitation showed that KhpA/KhpB bind an overlapping set of RNAs in cells. Phosphorylation of KhpB reported previously does not affect KhpB function in the D39 progenitor background. A chromosome duplication implicated FtsA overproduction in Δpbp2b suppression. We show that cellular FtsA concentration is negatively regulated by KhpA/B at the post-transcriptional level and that FtsA overproduction is necessary and sufficient for suppression of Δpbp2b. However, increased FtsA only partially accounts for the phenotypes of ΔkhpA mutants. Together, these results suggest that multimeric KhpA/B may function as a pleiotropic RNA chaperone controlling pneumococcal cell division., (© 2017 John Wiley & Sons Ltd.)

Objectives: The aim of this study was to explore the choice of transportation mode to hospital in patients with acute coronary syndrome (ACS) and to determine the factors influencing the use of ambulance., Design, Setting and Participants: This cross-sectional study was conducted in a tertiary and teaching hospital in China. The study was carried out between 24 August 2015 and 24 July 2016. A total of 828 patients with ACS presented at the emergency department (ED) were included. The study population was dichotomised according to their primary mode of transport (ambulance or self-transport) to hospital. Social demographics, cardiovascular history, risk factors, prehospital medications, clinical characteristics and symptom characteristics were collected. Multivariable logistic regression was used to examine the factors associated with ambulance use., Results: We found that only 179 (21.6%) patients with ACS chose taking ambulance to hospital. Factors associated with ambulance use were single (OR 1.66, 95% CI 1.07 to 2.57), taking Suxiaojiuxin pills (OR 1.91, 1.31 to 2.80) or nitrates (OR 2.91, 1.70 to 4.99) before going to hospital, diagnosed as ST-elevation myocardial infarction (STEMI) (OR 2.43, 1.45 to 4.05), with persistent symptoms (OR 1.95, 1.33 to 2.86) and symptoms accompanied with vomiting (OR 2.35, 1.19 to 4.62). The patients who had symptoms precipitated or aggravated by exercise (OR 0.37, 0.14 to 0.98) tended to choose self-transport., Conclusion: The usage of ambulance in patients with ACS presenting to the ED was low in China. Factors like single, taking Suxiaojiuxin pills or nitrates before going to hospital, diagnosed as STEMI, accompanied with vomiting and persistent symptoms were independently associated with ambulance use. Future education programmes should focus on these factors and increase people's knowledge on ACS and the benefits of ambulance use., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

GpsB regulatory protein and StkP protein kinase have been proposed as molecular switches that balance septal and peripheral (side-wall like) peptidoglycan (PG) synthesis in Streptococcus pneumoniae (pneumococcus); yet, mechanisms of this switching remain unknown. We report that ΔdivIVA mutations are not epistatic to ΔgpsB division-protein mutations in progenitor D39 and related genetic backgrounds; nor is GpsB required for StkP localization or FDAA labeling at septal division rings. However, we confirm that reduction of GpsB amount leads to decreased protein phosphorylation by StkP and report that the essentiality of ΔgpsB mutations is suppressed by inactivation of PhpP protein phosphatase, which concomitantly restores protein phosphorylation levels. ΔgpsB mutations are also suppressed by other classes of mutations, including one that eliminates protein phosphorylation and may alter division. Moreover, ΔgpsB mutations are synthetically lethal with Δpbp1a, but not Δpbp2a or Δpbp1b mutations, suggesting GpsB activation of PBP2a activity. Consistent with this result, co-IP experiments showed that GpsB complexes with EzrA, StkP, PBP2a, PBP2b and MreC in pneumococcal cells. Furthermore, depletion of GpsB prevents PBP2x migration to septal centers. These results support a model in which GpsB negatively regulates peripheral PG synthesis by PBP2b and positively regulates septal ring closure through its interactions with StkP-PBP2x., (© 2016 John Wiley & Sons Ltd.)

Unlike most bacteria, Streptococcus pneumoniae (pneumococcus) has two evolutionarily distinct ABC transporters (Pst1 and Pst2) for inorganic phosphate (Pi) uptake. The genes encoding a two-component regulator (PnpRS) are located immediately upstream of the pst1 operon. Both the pst1 and pst2 operons encode putative PhoU-family regulators (PhoU1 and PhoU2) at their ends. This study addresses why S. pneumoniae contains dual Pi uptake systems and the regulation and contribution of the Pst1 and Pst2 systems in conditions of high (mM) Pi amount and low (μM) Pi amount. We show that in unencapsulated mutants, both pst1 and pst2 can be deleted, and Pi is taken up by a third Na(+)/Pi co-transporter, designated as NptA. In contrast, either pst1 or pst2 is unexpectedly required for the growth of capsule producing strains. We used a combination of mutational analysis, transcript level determinations by qRT-PCR and RNA-Seq, assays for cellular PnpR~P amounts by SDS-PAGE, and pulse-Pi uptake experiments to study the regulation of Pi uptake. In high Pi medium, PhoU2 serves as the master negative regulator of Pst2 transporter function and PnpR~P levels (post-transcriptionally). ΔphoU2 mutants have high PnpR~P levels and induction of the pst1 operon, poor growth, and sensitivity to antibiotics, possibly due to high Pi accumulation. In low Pi medium, Pst2 is still active, but PnpR~P amount and pst1 operon levels increase. Together, these results support a model in which pneumococcus maintains high Pi transport in high and low Pi conditions that is required for optimal capsule biosynthesis.

In ellipsoid-shaped ovococcus bacteria, such as the pathogen Streptococcus pneumoniae (pneumococcus), side-wall (peripheral) peptidoglycan (PG) synthesis emanates from midcells and is catalyzed by the essential class B penicillin-binding protein PBP2b transpeptidase (TP). We report that mutations that inactivate the pneumococcal YceG-domain protein, Spd&#95;1346 (renamed MltG), remove the requirement for PBP2b. ΔmltG mutants in unencapsulated strains accumulate inactivation mutations of class A PBP1a, which possesses TP and transglycosylase (TG) activities. The 'synthetic viable' genetic relationship between Δpbp1a and ΔmltG mutations extends to essential ΔmreCD and ΔrodZ mutations that misregulate peripheral PG synthesis. Remarkably, the single MltG(Y488D) change suppresses the requirement for PBP2b, MreCD, RodZ and RodA. Structural modeling and comparisons, catalytic-site changes and an interspecies chimera indicate that pneumococcal MltG is the functional homologue of the recently reported MltG endo-lytic transglycosylase of Escherichia coli. Depletion of pneumococcal MltG or mltG(Y488D) increases sphericity of cells, and MltG localizes with peripheral PG synthesis proteins during division. Finally, growth of Δpbp1a ΔmltG or mltG(Y488D) mutants depends on induction of expression of the WalRK TCS regulon of PG hydrolases. These results fit a model in which MltG releases anchored PG glycan strands synthesized by PBP1a for crosslinking by a PBP2b:RodA complex in peripheral PG synthesis., (© 2016 John Wiley & Sons Ltd.)