Filamentous morphology engineering of bacteria by iron metabolism modulation through MagR expression.

The morphology is the consequence of evolution and adaptation. Escherichia coli is rod-shaped bacillus with regular dimension of about 1.5 µm long and 0.5 µm wide. Many shape-related genes have been identified and used in morphology engineering of this bacteria. However, little is known about if specific metabolism and metal irons could modulate bacteria morphology. Here in this study, we discovered filamentous shape change of E. coli cells overexpressing pigeon MagR, a putative magnetoreceptor and extremely conserved iron-sulfur protein. Comparative transcriptomic analysis strongly suggested that the iron metabolism change and iron accumulation due to the overproduction of MagR was the key to the morphological change. This model was further validated, and filamentous morphological change was also achieved by supplement E. coli cells with iron in culture medium or by increase the iron uptake genes such as entB and fepA. Our study extended our understanding of morphology regulation of bacteria, and may also serves as a prototype of morphology engineering by modulating the iron metabolism.

Bibliometric analysis of intestinal microbiota and lung diseases.

Background: Increasing evidence suggests a close association between the intestinal microbiome and the respiratory system, drawing attention to studying the gut-lung axis. This research employs bibliometric methods to conduct a visual analysis of literature in the field of intestinal microbiota and lung diseases over the past two decades. It offers scientific foundations for research directions and critical issues in this field. Methods: We retrieved all articles on intestinal microbiota and lung diseases from the SCI-Expanded of WoSCC on October 25, 2023. The analysis included original articles and reviews published in English from 2011 to 2023. We utilized Python, VOSviewer, and CiteSpace to analyze the retrieved data visually. Results: A total of 794 publications were analyzed. China ranked first in the number of publications, while the United States had the highest citations and H-index. Jian Wang was the most prolific author. Zhejiang University was the institution with the highest number of publications. Frontiers in Microbiology was the journal with the most publications. Author keywords appearing more than 100 times included "intestinal microbiota/microbiome", "microbiota/microbiome", and "gut-lung axis". Conclusion: The correlation and underlying mechanisms between intestinal microbiota and lung diseases, including asthma, COPD, lung cancer, and respiratory infections, remain hot topics in research. However, understanding the mechanisms involving the gut-lung axis is still in its infancy and requires further elucidation.

Effects of environmental pollutant benzop[α]yrene on the innate immunity of Scylla paramamosain and its mechanism.

Benzo[α]pyrene (BaP), a polycyclic aromatic hydrocarbon, is present in the aquatic environment and may be harmful to aquatic animals. We exposed the mud crab Scylla paramamosain to BaP for 7 days, the of superoxide dismutase (SOD), catalase (CAT), phenoloxidase (PO), lysozyme (LZM), glutathione (GSH), glutathione-S-transferase (GST), and acid phosphatase (ACP) activities in the hemolymph of mud crab were reduced. Additionally, the reactive oxygen species content was increased in mud crabs after exposed to BaP. When BaP concentration was increased, the total hemocyte count (THC), the survival rate of hemocytes and their proliferation were decreased. Histopathology analysis revealed damaged hepatopancreas cells, which indicating that BaP exposure is cytotoxic to crab hemocytes. However, the degree of DNA damage did not worsen with increasing BaP concentration. The expression levels of p53, MCM7, Caspase-3, and Myosin were changed with increasing concentration of BaP, which indicated that BaP exposure may affect apoptosis and phagocytosis in mud crabs. As BaP concentration was increased, the apoptosis rate of hemocytes was increased and the phagocytosis was decreased. These results confirmed that BaP exposure inhibited the innate immune response of mud crabs. A possible explanation for this effect is that BaP reduces the antioxidant enzyme activity and increases the reactive oxygen species content in mud crabs, thereby oxidizing and damaging hemocytes, which stimulates phagocytosis and apoptosis and negatively affects the innate immunity of S. paramamosain.

The hematopoietic cytokine Astakine play a vital role in hemocyte proliferation and innate immunity in Scylla paramamosain.

Astakine may induce hematopoietic response in crustaceans, as it is necessary for hemocyte proliferation. In this study, we produced the recombinant Scylla paramamosain Astakine (rspAstakine) and assessed its immunomodulatory function. We analyzed its amino acid sequences and generated a three-dimensional model, then ligand binding sites and enzyme commission of spAstakine were predicted. The rspAstakine was identified at 21.3 kDa by Western blot and liquid chromatography-mass spectrometry. The results showed that rspAstakine induced proliferation of hemocytes in mud crab in vivo and in vitro. The expression of immune-related genes was up-regulated after rspAstakine treatment, similarly to the immunity-related parameters, activities of superoxide dismutase, phenoloxidase, lysozyme, and peroxidase. Additionally, the intracellular content of reactive oxygen species was higher in the rspAstakine treatment group than PBS group. The rspAstakine also enhanced the rate of phagocytosis, while reduced the apoptosis rate of hemocytes after Vibrio alginolyticus infection. The mortalities of the V. alginolyticus only group and rspAstakine + V. alginolyticus group were 83.3 % and 58.3 %, respectively, which illustrated that rspAstakine plays a protective role against V. alginolyticus infection in S. paramamosain. Our results demonstrate the potential of Astakine to enhance the proliferation and immunomodulatory function of hemocytes in crustaceans.

Towards magnetism in pigeon MagR: Iron- and iron-sulfur binding work indispensably and synergistically.

The ability to navigate long distances is essential for many animals to locate shelter, food, and breeding grounds. Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field. A highly conserved iron-sulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor (MagR). Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception. In the current study, we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons, an avian species that relies on the geomagnetic field for navigation and homing. Pigeon MagR showed significantly higher total iron content from both iron- and iron-sulfur binding. Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding, and its mutation abolished iron-binding capacity of the protein. Surprisingly, both iron binding and iron-sulfur binding demonstrated synergistic effects, and thus appear to be integral and indispensable to pigeon MagR magnetism. These results not only extend our current understanding of the origin and complexity of MagR magnetism, but also imply a possible molecular explanation for the huge diversity in animal magnetoreception.

The rational design of iron-sulfur cluster binding site for prolonged stability in magnetoreceptor MagR.

Iron-sulfur proteins play essential roles in a wide variety of cellular processes such as respiration, photosynthesis, nitrogen fixation and magnetoreception. The stability of iron-sulfur clusters varies significantly between anaerobic and aerobic conditions due to their intrinsic sensitivity to oxygen. Iron-sulfur proteins are well suited to various practical applications as molecular redox sensors or molecular "wires" for electron transfer. Various technologies have been developed recently using one particular iron-sulfur protein, MagR, as a magnetic tag. However, the limited protein stability and low magnetic sensitivity of MagR hindered its wide application. Here in this study, the iron-sulfur binding site of pigeon clMagR was rationally re-designed. One such mutation, T57C in pigeon MagR, showed improved iron-sulfur binding efficiency and higher iron content, as well as prolonged thermostability. Thus, clMagRT57C can serve as a prototype for further design of more stable and sensitive magnetic toolbox for magnetogenetics in the future.

Nadir Oxygen Delivery During Pediatric Bypass as a Predictor of Acute Kidney Injury.

BACKGROUND: Cardiac surgery-associated acute kidney injury (CS-AKI) is common in infants and is associated with negative outcomes. Nadir indexed oxygen delivery (DO2i) during cardiopulmonary bypass (CPB) is associated with the occurrence of postoperative CS-AKI, with critical thresholds for DO2i reported to be 262 to 300 mL/min/m2 in adults. However, given that infants have a higher metabolic rate and oxygen demand, the critical DO2i in infants is not comparable with existing adult standards. This study aimed to explore the critical DO2i threshold during pediatric CPB. METHODS: Between March 2019 and April 2020, 106 consecutive infants undergoing cardiac surgery with CPB were admitted to this prospective observational cohort study. The DO2i levels of each patient were monitored during CPB. Pre- and intraoperative factors were tested for independent association with CS-AKI. The postoperative outcomes of patients with or without CS-AKI were compared. RESULTS: In our patient population (n = 83), we identified 25 patients (38.5%) with postoperative CS-AKI. Multivariate analysis revealed 2 independent risk factors for onset of CS-AKI: CPB duration and nadir DO2i. The lowest suitable DO2i during CPB in the present population was 353 mL/min/m2 (sensitivity, 65.6%; specificity, 74.5%). CS-AKI during pediatric CPB remained significantly associated with an increased morbidity, related mainly to a postoperative low cardiac output syndrome, but not to mortality. CONCLUSIONS: The lowest suitable DO2i during CPB in the infant population undergoing cardiac surgery was 353 mL/min/m2. Below this threshold, there was a high probability of inducing CS-AKI.

Quantification of Acute Myocardial Damage Secondary to Implantation of Electrodes for the Left Bundle Branch Area Pacing

ABSTRACT Background: Different from the traditional right ventricular pacing, the left bundle branch area pacing (LBBAP) is accomplished with deeper lead implantation and more attempts. However, myocardial damage is unclear in LBBAP. Objective: The objective of the study was to observe the change of troponin T and explore possible factors associated with greater myocardial damage in LBBAP. Methods: Patients with an indication for pacemaker implantation underwent attempts for LBBAP by transventricular septal method. Levels of troponin T were determined before operation, 12 h and 1 week after the operation. Parameters of intraoperation and follow-up were recorded and analyzed. Results: In total, successful LBBAP was achieved in 126 patients. The levels of troponin T increased significantly at 12 h after the operation compared with those before operation (96.45 ± 11.07 [69.06] vs. 16.59 ± 1.84 [11.92] ng/L, p < 0.001), while there were no significant differences between pre- and post-operative levels at 1 week. Correlation and regression analysis showed that only the number of attempts was an independent factor related to the change of troponin T. During 1 year of follow-up, LBBAP was safe and feasible with few complications. Conclusions: Myocardial damage of LBBAP was clinically significant. The number of attempts was an independent factor related to the myocardial damage.

Exploration of SQC Formula Effect on Type 2 Diabetes Mellitus by Whole Transcriptome Profile in Rats.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that has turned out to be a pandemic all over the world. In China, some traditional Chinese herbal formulas have enjoyed a high reputation in T2DM treatment for centuries. METHODS: In this study, ShenQi compound (SQC) is proposed, a formula that has been performed on T2DM clinical therapeutics in China for many years. The efficacy of SQC in a diabetic rat model by measuring food and water intake and examining islet microcirculatory index involves islets microvessel quantity and density, islets size, pancreatic microvascular wall thickness is evaluated. Meanwhile, gene microarray experiments were performed to explore the molecular mechanism of SQC treatment. In addition, a western medicine, metformin, was employed as a comparison. RESULTS: The results indicated that SQC could effectively improve polydipsia, polyphagia and weight loss caused by diabetes as well as pancreatic tissue damage and vascular injury for T2DM. Meanwhile, the gene microarray experiments indicated that SQC may improve the T2DM by affecting the biological functions related to detection of chemical stimulus involved in sensory perception of smell, G-protein coupled receptor signaling pathway, cytoplasmic translation. In addition, SQC presented curative effect by the regulated function associated with translation, while metformin presented curative effect by the regulated function associated coagulation. CONCLUSION: SQC is an effective therapeutic drug on T2DM, and presents curative effect by regulated function associated with translation.

Goal-directed perfusion to reduce acute kidney injury after paediatric cardiac surgery (GDP-AKIp): study protocol for a prospective randomised controlled trial.

INTRODUCTION: Cardiac surgery-associated acute kidney injury (CS-AKI) occurs in up to 40%~60% of paediatric patients and increases postoperative morbidity and mortality. A goal-directed perfusion (GDP) strategy aimed at maintaining indexed oxygen delivery (DO2i) above the critical threshold (reported to be 260~300 mL/min/m2 in adults) during cardiopulmonary bypass (CPB), is effective in reducing the incidence of CS-AKI. However, no clear standards of paediatric critical DO2i exist. Our prior prospective cohort study exploring the critical DO2i threshold during paediatric CPB has found the nadir DO2i <353 mL/min/m2 was an independent risk predictor of CS-AKI. Based on this background, this trial is designed to further determine whether the implementation of the GDP initiative aimed at maintaining DO2i ≥360 mL/min/m2 would reduce the rate of CS-AKI in paediatrics and improve clinical outcome. METHODS AND ANALYSIS: This is a prospective, single-centre, randomised controlled trial. In total, 166 paediatric patients undergoing cardiac surgery will be randomly allocated to the GDP group or control group. Patients in the GDP arm will be treated with a GDP strategy during CPB aimed to maintain DO2i at ≥360 mL/min/m2 (to ensure safely above the risk DO2i threshold we found). The perfusion strategy for patients in the control arm will be factored on body surface area and temperature. The primary outcome is the rate of postoperative CS-AKI (it is defined according to paediatric Risk, Injury, Failure, Loss of renal function and End-stage renal disease criteria). The secondary end points include: (1) the other oxygen metabolism parameters during CPB; (2) major complication and all-cause mortality (in-hospital or within 30 days postoperatively); (3) short-term clinical outcomes (ie, time to extubation, mechanical ventilation time, hospital stay). ETHICS AND DISSEMINATION: The study has been approved by the Biomedical Research Ethics committee of West China Hospital of Sichuan University (approval number: 2019(863)). Results will be disseminated through peer-reviewed publications and conferences. TRIAL REGISTRATION NUMBER: ChiCTR2000029232.

Beneficial Effects of Sacubitril/Valsartan at Low Doses in an Asian Real-World Heart Failure Population.

This study aimed at analyzing the clinical profile of real-world patients with heart failure with reduced ejection fraction (HFrEF) and evaluating the safety and efficacy of sacubitril/valsartan among Asian patients in daily practice. We conducted a single-center prospective observational cohort study of HFrEF patients treated with sacubitril/valsartan from September 2017 to September 2018 with a follow-up of 6 months. The mean (SD) age of the 110 patients enrolled was 59.7 ± 13.3, 85 (77.3%) were men and 41 (37.3%) had ischemic cardiomyopathy. Thirty-one (27.2%) patients with low systolic blood pressure initiated sacubitril/valsartan on a tiny dose of 12/13 mg. Despite the low mean daily dose achieved in real world mainly because of hypotension, left ventricular ejection fraction increased significantly from 35.4 ± 8.9% at baseline to 43.0 ± 12.2% after 6-month follow-up (P < 0.001). We also observed a significant improvement in a 6-minute walk test (6-MWT) distance and N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration reduction. No severe adverse event was recorded. Low dose sacubitril/valsartan induces beneficial cardiac reverse remodeling and improves clinical functional performance in real-world HFrEF patients without severe adverse effect. A tiny initial dose may enhance tolerability and reduce discontinuation rate by minimizing hypotension events in patients with low systolic blood pressure. These data further support using low-dose sacubitril/valsartan among eligible patients with HFrEF in Asia.

Characterization of Antibiotic Resistance Genes, Plasmids, Biofilm Formation, and In Vitro Invasion Capacity of Salmonella Enteritidis Isolates from Children with Gastroenteritis.

Objectives: The primary aim of this study was to investigate the presence of antibiotic resistance genes (ARGs) and plasmid replicon types for 75 multidrug-resistant (MDR) Salmonella Enteritidis isolates from children with gastroenteritis. We also evaluated the association among biofilm formation, in vitro invasion capacity, and antibiotic resistance phenotypes. Materials and Methods: Twenty-two ARGs and 18 different plasmid incompatibility types were investigated using polymerase chain reaction (PCR) and DNA sequencing. In vitro invasion capacity of S. Enteritidis isolates possessing different antibiotic resistance patterns was assessed using the Caco2 human intestinal epithelial cell line and biofilm formation was performed in a 96-well polystyrene well format using crystal violet detection. Results: The presence of plasmid-mediated quinolone resistance genes and ß-lactamase genes was established using PCR amplification. All the tested S. Enteritidis isolates that were fluoroquinolone resistant possessed gyrA mutations and 50% also possessed mutations in parC. MDR S. Enteritidis isolates containing three (29/75) or four (21/75) plasmid replicon types were predominant and 71/75 carried both FIIs and FIC replicon-type plasmids. MDR isolates were strong or moderate biofilm producers and a significant positive association (p < 0.05) between antibiotic resistance and biomass of biofilms was observed in the strains assayed. A ceftiofur-resistant strain was significantly more invasive (p < 0.01) than the other isolates. Conclusions: We observed a high incidence of ARGs and diversity of plasmids in S. Enteritidis isolates from children. Biofilm formation and invasion capacity highlight a significant hazard to public health.

Subchronic Hepatotoxicity Effects of 6:2 Chlorinated Polyfluorinated Ether Sulfonate (6:2 Cl-PFESA), a Novel Perfluorooctanesulfonate (PFOS) Alternative, on Adult Male Mice.

The compound 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA), an alternative to perfluorooctanesulfonate (PFOS) in the metal-plating industry, has been widely detected in various environmental matrices. However, its hepatotoxicity has yet to be clarified. Here, male mice were exposed to 0.04, 0.2, or 1 mg/kg/day of 6:2 Cl-PFESA for 56 days. Results demonstrated that relative liver weight increased significantly in the 0.2 and 1 mg/kg/day 6:2 Cl-PFESA groups, whereas liver lipid accumulation increased in all 6:2 Cl-PFESA groups. Serum enzyme activities of alanine transaminase and alkaline phosphatase were increased. Serum triglycerides and low-density lipoprotein cholesterol both increased, whereas serum total cholesterol and high-density lipoprotein cholesterol decreased following 6:2 Cl-PFESA exposure. A total of 264 differentially expressed proteins (127 up-regulated and 137 down-regulated), mainly involved in lipid metabolism, xenobiotic metabolism, and ribosome biogenesis, were identified by quantitative proteomics. Bioinformatics analysis highlighted the de-regulation of PPAR and PXR, which may contribute to the hepatotoxicity of 6:2 Cl-PFESA. Additionally, 6:2 Cl-PFESA induced both cell apoptosis and proliferation in the mouse liver. Compared to the overt toxicity of PFOS, 6:2 Cl-PFESA exhibited more-serious hepatotoxicity. Thus, caution should be exercised in the application of 6:2 Cl-PFESA as a replacement alternative to PFOS in industrial areas.

Subchronic reproductive effects of 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES), an alternative to PFOS, on adult male mice.

With a similar structure to perfluorooctane sulfonate (PFOS), 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFAES) has been widely used as a mist suppressant in the chromium plating industry in China since the 1970s. After being disregarded for the past 30 years, 6:2 Cl-PFAES has now been detected in environmental matrices and human sera, suggesting potential health concerns. We carried out a subchronic exposure study to investigate the reproductive toxicity of 6:2 Cl-PFAES exposure (0, 0.04, 0.2, and 1.0 mg/kg/d body weight, 56 d) in adult male BALB/c mice. Results showed that relative epididymis and testis weights decreased in the 1.0 mg/kg/d group compared with the control. However, no changes were observed in the serum levels of testosterone, estradiol, follicle-stimulating hormone (FSH), or luteinizing hormone (LH), nor in the histopathological structure of the epididymis and testis and sperm count. In addition, 56 d of consecutive gavage of 1.0 mg/kg/d of 6:2 Cl-PFAES did not affect male mouse fertility. RNA sequencing showed that no genes were significantly altered in the testes after 6:2 Cl-PFAES exposure. Several testicular genes, which are sensitive to PFOS exposure, were also detected using Western blotting, and included steroidogenic proteins, STAR, CYP11A1, CYP17A1, and 3ß-HSD and cell junction proteins, occludin, ß-catenin, and connexin 43; however, none were changed after 6:2 Cl-PFAES exposure. Except for a decrease in the relative epididymis and testis weights in the 1.0 mg/kg/d group, 6:2 Cl-PFAES exposure for 56 d exerted no significant effect on the serum levels of reproductive hormones or the testicular mRNA profilesin adult male mice, implying a relative weak reproductive injury potential compared with that of PFOS.

Influence of Renal Sympathetic Denervation in Patients with Early-Stage Heart Failure Versus Late-Stage Heart Failure.

Renal sympathetic denervation (RDN) is currently being investigated in multiple studies of heart failure (HF). Our aim was to assess the safety and effectiveness of RDN in patients with HF, and determine which patients could achieve more beneficial effects of RDN. A total of 17 consecutive patients with HF were enrolled in the study. Clinical symptoms, office blood pressure, and laboratory results were obtained and echocardiography was performed before and 12 months after RDN. Changes from baseline to 12 months were analyzed for all patients and for two subgroups based on HF duration (group 1: HF duration ≤ 3 years, n = 9; group 2: HF duration > 3 years, n = 8). The RDN procedure was successful in all patients and no procedure-related complications were documented. In comparison to baseline, there was a significant increase in left ventricular ejection fraction (LVEF) in all patients and group 1 (P < 0.05 for both), which did not happen in group 2. LAD, LVDs, and RVD also showed a significant reduction in group 1 (P < 0.05 for both). At 12 months, the reductions in TNF-α and CRP were significant for all patients and for patients in group 1 separately. No obvious changes in echocardiographic parameters, 6-minute walking distance, TNF-α, or CRP were recorded in group 2. No changes in BNP in either group were observed at the 12th month of follow-up. RDN could improve cardiac function and led to a significant drop in inflammatory markers in patients with HF. We also found that patients in early-stage HF could benefit more from RDN.

Comprehensive analysis of desmosomal gene mutations in Han Chinese patients with arrhythmogenic right ventricular cardiomyopathy.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a cardiomyopathy that primarily involves the right ventricle. Mutations in desmosomal genes have been associated with ARVC. But its prevalence and spectrum are much less defined in the Chinese population, especially Han Chinese, a majority ethnic group in China; also the genotype-phenotype correlation regarding left ventricular involvement is still poorly understood. The aim of this study was to elucidate the genotype in Han Chinese patients with ARVC and the phenotype regarding cardiac left ventricle involvement in mutation carriers of ARVC. 48 Han Chinese patients were recruited into the present study based on the Original International Task Force Criteria of ARVC. Clinical data were reassessed according to the modified criteria published in 2010. A total of 36 subjects were diagnosed with ARVC; 12 patients were diagnosed with suspected ARVC. Five desmosomal genes (PKP2, DSG2, DSP, DSC2 and JUP) were sequenced directly from genomic DNA. Among the 36 patients, 21 mutations, 12 of which novel, were discovered in 19 individuals (19 of 36, 53%). The distribution of the mutations was 25% in PKP2, 14% in DSP, 11% in DSG2, 6% in JUP, and 3% in DSC2. Multiple mutations were identified in 2 subjects (2 of 36, 6%); both had digenic heterozygosity. Eight mutations, of which six were novel, were located in highly conserved regions. Seven mutations introduced a stop codon prematurely, which would result in premature termination of the protein synthesis. Two-dimensional echocardiography showed that LDVd and LDVs parameters were significantly larger in nonsense mutation carriers than in carriers of other mutations. In this comprehensive desmosome genetic analysis, 21 mutations were identified in five desmosomal genes in a group of 48 local Han Chinese subjects with ARVC, 12 of which were novel. PKP2 mutations were the most common variants. Left ventricular involvement could be a sign that the patient is a carrier of a nonsense cardiac desmosomal gene mutation.