The identification of PSEN1 p.Tyr159Ser mutation in a non-canonic early-onset Alzheimer's disease family.

More than 300 missense mutations in PSEN1 gene have been correlated to the early-onset Alzheimer's disease (EOAD), but given the high diversity of PS1 (the PSEN1 gene product) substrates and the involvement of PS1 in multiple biological functions, different mutants may represent different EOAD etiologies, and how each mutant contributes to the EOAD remains to be further investigated. Here we report the identification of a novel PSEN1 p.Tyr159Ser in a family with multiple EOAD cases. The mutant PS1 protein (PS1Y159S) was analyzed for its activity in producing amyloid-ß (Aß) and for the efficiency in maturation in vitro. We also screened other mutations and SNPs that may modify the effect of PSEN1 p.Tyr159Ser on AD pathogenesis. The blood samples of the family were collected for whole-exome gene sequencing and analysis. The identified mutant PS1 and several other PS1 mutants were co-expressed with the APP Swedish mutant to compare the effects on APP processing and PS1 maturation.1. The proband and her siblings over 50 years old showed typical AD or MCI symptoms. Exon sequencing identified the p.Tyr159Ser mutation in the PSEN1 gene. As not until the age of 78 did the proband's mother who carried this mutation displayed the symptoms of uncharacterized neuropsychiatry instead of AD, but all the mutation bearing lower generation developed AD or MCI after the age of 50, we also analyzed mutations/SNPs that are different between the mother and the lower generation. By in vitro assays, we found that the Y159S substitution strongly increased Aß42/Aß40 ratio and significantly affected PS1 maturation. The newly discovered PSEN1 p.Tyr159Ser is an AD-causing mutation, yet, the carriers are not obligated AD patients. Mutations/SNPs in other gene may modify the effects of this mutation, and the identification of these mutations/SNPs may facilitate the discovery of AD-preventing mechanisms and methods.

Citric Acid Confers Broad Antibiotic Tolerance through Alteration of Bacterial Metabolism and Oxidative Stress.

Antibiotic tolerance has become an increasingly serious crisis that has seriously threatened global public health. However, little is known about the exogenous factors that can trigger the development of antibiotic tolerance, both in vivo and in vitro. Herein, we found that the addition of citric acid, which is used in many fields, obviously weakened the bactericidal activity of antibiotics against various bacterial pathogens. This mechanistic study shows that citric acid activated the glyoxylate cycle by inhibiting ATP production in bacteria, reduced cell respiration levels, and inhibited the bacterial tricarboxylic acid cycle (TCA cycle). In addition, citric acid reduced the oxidative stress ability of bacteria, which led to an imbalance in the bacterial oxidation-antioxidant system. These effects together induced the bacteria to produce antibiotic tolerance. Surprisingly, the addition of succinic acid and xanthine could reverse the antibiotic tolerance induced by citric acid in vitro and in animal infection models. In conclusion, these findings provide new insights into the potential risks of citric acid usage and the relationship between antibiotic tolerance and bacterial metabolism.

Pre-Configured Error Pattern Ordered Statistics Decoding for CRC-Polar Codes.

In this paper, we propose a pre-configured error pattern ordered statistics decoding (PEPOSD) algorithm and discuss its application to short cyclic redundancy check (CRC)-polar codes. Unlike the traditional OSD that changes the most reliable independent symbols, we regard the decoding process as testing the error patterns, like guessing random additive noise decoding (GRAND). Also, the pre-configurator referred from ordered reliability bits (ORB) GRAND can better control the range and testing order of EPs. An offline-online structure can accelerate the decoding process. Additionally, we also introduce two orders to optimize the search order for testing EPs. Compared with CRC-aided OSD and list decoding, PEPOSD can achieve a better trade-off between accuracy and complexity.

Circ_FOXP1 promotes the growth and survival of high glucose-treated human trophoblast cells through the regulation of miR-508-3p/SMAD family member 2 pathway.

Gestational diabetes mellitus (GDM) is a health risk for pregnant women and infants. Emerging evidence suggests that the deregulation of circular RNAs (circRNAs) is associated with the progression of this disorder. The objective of this study was to investigate the role of circ_FOXP1 in GDM. Cell models of GDM were established by treating human trophoblast cells with high glucose (HG). The expression of circ_FOXP1, miR-508-3p and SMAD family member 2 (SMAD2) mRNA was detected by quantitative real-time PCR (qPCR). Cell proliferation was assessed by EdU assay and MTT assay, and cell cycle and cell apoptosis were determined by flow cytometry assay. The protein levels of proliferation- and apoptosis-related markers and SMAD2 were measured by western blot. The relationship between miR-508-3p and circ_FOXP1 or SMAD2 was validated by dual-luciferase reporter assay or pull-down assay. The expression of circ_FOXP1 was downregulated in HG-treated HTR-8/SVneo cells. Circ_FOXP1 overexpression promoted HG-inhibited HTR-8/SVneo cell proliferation and suppressed HG-induced HTR-8/SVneo cell cycle arrest and apoptosis. Circ_FOXP1 positively regulated the expression of SMAD2 by targeting miR-508-3p. MiR-508-3p was overexpressed in HG-treated HTR-8/SVneo cells, and its overexpression reversed the effects of circ_FOXP1 overexpression. MiR-508-3p inhibition also alleviated HG-induced HTR-8/SVneo cell injuries, while the knockdown of SMAD2 abolished these effects. Collectively, circ_FOXP1 promotes the growth and survival of HG-treated human trophoblast cells through the miR-508-3p/SMAD2 pathway, hinting that circ_FOXP1 was involved in GDM progression.

An In Vivo Data-Based Computational Study on Sitting-Induced Hemodynamic Changes in the External Iliac Artery.

Although sedentary behavior (characterized by prolonged sitting without otherwise being active in daily life) is widely regarded as a risk factor for peripheral artery disease (PAD), underlying biomechanical mechanisms remain insufficiently understood. In this study, geometrical models of ten external iliac arteries were reconstructed based on angiographic data acquired from five healthy young subjects resting in supine and sitting (mimicked by side lying with bent legs) positions, respectively, which were further combined with measured blood flow velocity waveforms in the common iliac arteries (with each body posture being maintained for 30 min) to build computational models for simulating intra-arterial hemodynamics. Morphological analyses showed that the external iliac arteries suffered from evident bending deformation upon the switch of body posture from supine to sitting. Measured blood flow velocity waveforms in the sitting position exhibited a marked decrease in mean flow velocity while increase in retrograde flow ratio compared with those in the supine position. Hemodynamic computations further revealed that sitting significantly altered blood flow patterns in the external iliac arteries, leading to a marked enlargement of atheroprone wall regions exposed to low and oscillatory wall shear stress (WSS), and enhanced multidirectional disturbance of WSS that may further impair endothelial function. In summary, our study demonstrates that prolonged sitting induces atheropromoting hemodynamic changes in the external iliac artery due to the combined effects of vascular bending deformation and changes in flow velocity waveform, which may provide important insights for understanding the involvement of biomechanical factors in sedentary behavior-related PAD.

Integrated Microfluidic Synthesis of Aptamer Functionalized Biozeolitic Imidazolate Framework (BioZIF-8) Targeting Lymph Node and Tumor.

Targeted delivery of therapeutic molecules using nanomaterials is desired to elicit specific responses toward diseases. Such an integrated synthesis of functional material using a microfluidic approach is a great challenge. Functional metal organic frameworks (MOFs) with unique structural diversity possess a complicated synthesis procedure thereby requiring a modest, straightforward approach to synthesize size-controllable MOFs. Here, we develop an integrated microfluidic chip to synthesize the aptamer-modified biozeolitic imidazolate framework (BioZIF-8) to target the lymph node and tumor. The first stage of the microfluidic chip forms the ZIF-8 encapsulating biomolecules (bovine serum albumin, small interfering ribonucleic acid, and doxorubicin). The second stage modifies the surface of BioZIF-8 with the aptamer. Our approach reduces the overall synthesis time (∼3 mg/10 min against 15 h for the conventional two-step method) and encapsulates a higher number of biomolecules. The microfluidic approach realizes the rapid and fine-tuned synthesis of functional MOFs integrated into one-step.

Use of Microfluidics to Fabricate Bioerodable Lipid Hybrid Nanoparticles Containing Hydromorphone or Ketamine for the Relief of Intractable Pain.

PURPOSE: For patients with intractable cancer-related pain, administration of strong opioid analgesics and adjuvant agents by the intrathecal (i.t.) route in close proximity to the target receptors/ion channels, may restore pain relief. Hence, the aim of this study was to use bioerodable polymers to encapsulate an opioid analgesic (hydromorphone) and an adjuvant drug (ketamine) to produce prolonged-release formulations for i.t. injection. METHODS: A two-stage microfluidic method was used to fabricate nanoparticles (NPs). The physical properties were characterised using dynamic light scattering and transmission electron microscopy. A pilot in vivo study was conducted in a rat model of peripheral neuropathic pain. RESULTS: The in vitro release of encapsulated payload from NPs produced with a polymer mixture (CPP-SA/PLGA 50:50) was sustained for 28 days. In a pilot in vivo study, analgesia was maintained over a three day period following i.t. injection of hydromorphone-loaded NPs at 50 µg. Co-administration of ketamine-loaded NPs at 340 µg did not increase the duration of analgesia significantly. CONCLUSIONS: The two-stage microfluidic method allowed efficient production of analgesic/adjuvant drug-loaded NPs. Our proof-of-principle in vivo study shows prolonged hydromorphone analgesic for 78 h after single i.t. injection. At the i.t. dose administered, ketamine released from NPs was insufficient to augment hydromorphone analgesia.

Sub-10†nm Aggregation-Induced Emission Quantum Dots Assembled by Microfluidics for Enhanced Tumor Targeting and Reduced Retention in the Liver.

A robust platform is developed to assemble sub-10 nm organic aggregation-induced emission (AIE) particles using four different AIE luminogens (AIEgens) with emissions from green to the second near-infrared window (NIR-II). They are called AIE quantum dots (QDs) to distinguish from typical AIE dots which are larger than 25 nm. Compared with AIE dots that are larger than 25 nm, AIE QDs allow more efficient cellular uptake and imaging without surface modification of any membrane-penetrating peptides or other targeting molecules. NIR-II AIEgens, which have nearly no background fluorescence from organisms, are used to demonstrate that AIE QDs can achieve high contrast at the tumor as small as 80 mm3 and evade the liver more efficiently than AIE dots. AIE QDs hold a good promise for sensitive and precise diagnosis of the latent solid tumor in clinical medicine with much lower off-targeting to the liver than AIE dots.

One-Step Microfluidic Synthesis of Nanocomplex with Tunable Rigidity and Acid-Switchable Surface Charge for Overcoming Drug Resistance.

Multidrug resistance (MDR), is the key reason accounting for the failure of cancer chemotherapy, remains a dramatic challenge for cancer therapy. In this study, the one-step microfluidic fabrication of a rigid pH-sensitive micellar nanocomplex (RPN) with tunable rigidity and acid-switchable surface charge for overcoming MDR by enhancing cellular uptake and lysosome escape is demonstrated. The RPN is composed of a poly(lactic-co-glycolic acid) (PLGA) core and a pH-sensitive copolymer shell, which is of neutral surface charge during blood circulation. Upon internalization of RPN by cancer cells, the pH-responsive shell dissociates inside the acidic lysosomes, while the rigid and positively charged PLGA core improves the lysosomal escape. The cellular uptake and nuclear uptake of doxorubicin (Dox) from Dox-loaded RPN are 1.6 and 2.4 times higher than that from Dox-loaded pH-sensitive micelles (PM) using a Dox-resistant cancer model (MCF-7/ADR, re-designated NCI/ADR-RES) in vitro. Dox-loaded RPN significantly enhances the therapeutic efficacy (92% inhibition of tumor growth) against MCF-7/ADR xenograft tumor in mice, while Dox-loaded PM only inhibits the tumor growth by 36%. RPN avoids the use of complicated synthesis procedure of nanoparticle and the necessary to integrate multiple components, which can facilitate the clinical translation of this novel nanostructure.

Neuroimaging basis in the conversion of aMCI patients with APOE-ε4 to AD: study protocol of a prospective diagnostic trial.

BACKGROUND: The ε4 allele of the Apolipoprotein E gene (APOE-ε4) is a potent genetic risk factor for sporadic Alzheimer's disease (AD). Amnestic mild cognitive impairment (aMCI) is an intermediate state between normal cognitive aging and dementia, which is easy to convert to AD dementia. It is an urgent problem in the field of cognitive neuroscience to reveal the conversion of aMCI-ε4 to AD. Based on our preliminary work, we will study the neuroimaging features in the special group of aMCI-ε4 with multi-modality magnetic resonance imaging (structural MRI, resting state-fMRI and diffusion tensor imaging) longitudinally. METHODS/DESIGN: In this study, 200 right-handed subjects who are diagnosed as aMCI with APOE-ε4 will be recruited at the memory clinic of the Neurology Department, XuanWu Hospital, Capital Medical University, Beijing, China. All subjects will undergo the neuroimaging and neuropsychological evaluation at a 1 year-interval for 3 years. The primary outcome measures are 1) Microstructural alterations revealed with multimodal MRI scans including structure MRI (sMRI), resting state functional MRI (rs-fMRI), diffusion tensor imaging (DTI); 2) neuropsychological evaluation, including the World Health Organization-University of California-LosAngeles Auditory Verbal Learning Test (WHO-UCLA AVLT), Addenbrook's cognitive examination-revised (ACE-R), mini-mental state examination (MMSE), Montreal Cognitive Assessment (MoCA), Clinical Dementia Rating scale (CDR). DISCUSSION: This study is to find out the neuroimaging biomarker and the changing laws of the marker during the progress of aMCI-ε4 to AD, and the final purpose is to provide scientific evidence for new prevention, diagnosis and treatment of AD. TRIAL REGISTRATION: This study has been registered to ClinicalTrials.gov (NCT02225964, https://www.clinicaltrials.gov/ ) in August 24, 2014.

Abnormal Resting-State Functional Connectivity Strength in Mild Cognitive Impairment and Its Conversion to Alzheimer's Disease.

Individuals diagnosed with mild cognitive impairment (MCI) are at high risk of transition to Alzheimer's disease (AD). However, little is known about functional characteristics of the conversion from MCI to AD. Resting-state functional magnetic resonance imaging was performed in 25 AD patients, 31 MCI patients, and 42 well-matched normal controls at baseline. Twenty-one of the 31 MCI patients converted to AD at approximately 24 months of follow-up. Functional connectivity strength (FCS) and seed-based functional connectivity analyses were used to assess the functional differences among the groups. Compared to controls, subjects with MCI and AD showed decreased FCS in the default-mode network and the occipital cortex. Importantly, the FCS of the left angular gyrus and middle occipital gyrus was significantly lower in MCI-converters as compared with MCI-nonconverters. Significantly decreased functional connectivity was found in MCI-converters compared to nonconverters between the left angular gyrus and bilateral inferior parietal lobules, dorsolateral prefrontal and lateral temporal cortices, and the left middle occipital gyrus and right middle occipital gyri. We demonstrated gradual but progressive functional changes during a median 2-year interval in patients converting from MCI to AD, which might serve as early indicators for the dysfunction and progression in the early stage of AD.

Prediction value study of breast cancer tumor infiltrating lymphocyte levels based on ultrasound imaging radiomics.

Objective: Construct models based on grayscale ultrasound and radiomics and compare the efficacy of different models in preoperatively predicting the level of tumor-infiltrating lymphocytes in breast cancer. Materials and methods: This study retrospectively collected clinical data and preoperative ultrasound images from 185 breast cancer patients confirmed by surgical pathology. Patients were randomly divided into a training set (n=111) and a testing set (n=74) using a 6:4 ratio. Based on a 10% threshold for tumor-infiltrating lymphocytes (TIL) levels, patients were classified into low-level and high-level groups. Radiomic features were extracted and selected using the training set. The evaluation included assessing the relationship between TIL levels and both radiomic features and grayscale ultrasound features. Subsequently, grayscale ultrasound models, radiomic models, and nomograms combining radiomics score (Rad-score) and grayscale ultrasound features were established. The predictive performance of different models was evaluated through receiver operating characteristic (ROC) analysis. Calibration curves assessed the fit of the nomograms, and decision curve analysis (DCA) evaluated the clinical effectiveness of the models. Results: Univariate analyses and multivariate logistic regression analyses revealed that indistinct margin (P<0.001, Odds Ratio [OR]=0.214, 95% Confidence Interval [CI]: 0.103-1.026), posterior acoustic enhancement (P=0.027, OR=2.585, 95% CI: 1.116-5.987), and ipsilateral axillary lymph node enlargement (P=0.001, OR=4.214, 95% CI: 1.798-9.875) were independent predictive factors for high levels of TIL in breast cancer. In comparison to grayscale ultrasound model (Training set: Area under curve [AUC] 0.795; Testing set: AUC 0.720) and radiomics model (Training set: AUC 0.803; Testing set: AUC 0.759), the nomogram demonstrated superior discriminative ability on both the training (AUC 0.884) and testing (AUC 0.820) datasets. Calibration curves indicated high consistency between the nomogram model's predicted probability of breast cancer TIL levels and the actual occurrence probability. DCA revealed that the radiomics model and the nomogram model achieved higher clinical net benefits compared to the grayscale ultrasound model. Conclusion: The nomogram based on preoperative ultrasound radiomics features exhibits robust predictive capacity for the non-invasive evaluation of breast cancer TIL levels, potentially providing a significant basis for individualized treatment decisions in breast cancer.

Gene expression prediction based on neighbour connection neural network utilizing gene interaction graphs.

Having observed that gene expressions have a correlation, the Library of Integrated Network-based Cell-Signature program selects 1000 landmark genes to predict the remaining gene expression value. Further works have improved the prediction result by using deep learning models. However, these models ignore the latent structure of genes, limiting the accuracy of the experimental results. We therefore propose a novel neural network named Neighbour Connection Neural Network(NCNN) to utilize the gene interaction graph information. Comparing to the popular GCN model, our model incorperates the graph information in a better manner. We validate our model under two different settings and show that our model promotes prediction accuracy comparing to the other models.

Computational modeling of electromechanical coupling in human cardiomyocyte applied to study hypertrophic cardiomyopathy and its drug response.

BACKGROUND AND OBJECTIVE: Knowledge of electromechanical coupling in cardiomyocyte and how it is influenced by various pathophysiological factors is fundamental to understanding the pathogenesis of myocardial disease and its response to medication, which is however hard to be thoroughly addressed by clinical/experimental studies due to technical limitations. At this point, computational modeling offers an alternative approach. The main objective of the study was to develop a computational model capable of simulating the process of electromechanical coupling and quantifying the roles of various factors in play in the human left ventricular cardiomyocyte. METHODS: A new electrophysiological model was firstly built by combining several existing electrophysiological models and incorporating the mechanism of electrophysiological homeostasis, which was subsequently coupled to models representing the cross-bridge dynamics and active force generation during excitation-contraction coupling and the passive mechanical properties of cardiomyocyte to yield an integrative electromechanical model. Model parameters were calibrated or optimized based on a large amount of experimental data. The resulting model was applied to delineate the characteristics of electromechanical coupling and explore underlying determinant factors in hypertrophic cardiomyopathy (HCM) cardiomyocyte, as well as quantify their changes in response to different medications. RESULTS: Model predictions captured the major electromechanical characteristics of cardiomyocyte under both normal physiological and HCM conditions. In comparison with normal cardiomyocyte, HCM cardiomyocyte suffered from systemic changes in both electrophysiological and mechanical variables. Numerical simulations of drug response revealed that Mavacamten and Metoprolol could both reduce the active contractility and alleviate calcium overload but had marked differential influences on many other electromechanical variables, which theoretically explained why the two drugs have differential therapeutic effects. In addition, our numerical experiments demonstrated the important role of compensatory ion transport in maintaining electrophysiological homeostasis and regulating cytoplasmic volume. CONCLUSIONS: A sophisticated computational model has the advantage of providing quantitative and integrative insights for understanding the pathogenesis and drug responses of HCM or other myocardial diseases at the level of cardiomyocyte, and hence may contribute as a useful complement to clinical/experimental studies. The model may also be coupled to tissue- or organ-level models to strengthen the physiological implications of macro-scale numerical simulations.

The Influence of Aortic Valve Disease on Coronary Hemodynamics: A Computational Model-Based Study.

Aortic valve disease (AVD) often coexists with coronary artery disease (CAD), but whether and how the two diseases are correlated remains poorly understood. In this study, a zero-three dimensional (0-3D) multi-scale modeling method was developed to integrate coronary artery hemodynamics, aortic valve dynamics, coronary flow autoregulation mechanism, and systemic hemodynamics into a unique model system, thereby yielding a mathematical tool for quantifying the influences of aortic valve stenosis (AS) and aortic valve regurgitation (AR) on hemodynamics in large coronary arteries. The model was applied to simulate blood flows in six patient-specific left anterior descending coronary arteries (LADs) under various aortic valve conditions (i.e., control (free of AVD), AS, and AR). Obtained results showed that the space-averaged oscillatory shear index (SA-OSI) was significantly higher under the AS condition but lower under the AR condition in comparison with the control condition. Relatively, the overall magnitude of wall shear stress was less affected by AVD. Further data analysis revealed that AS induced the increase in OSI in LADs mainly through its role in augmenting the low-frequency components of coronary flow waveform. These findings imply that AS might increase the risk or progression of CAD by deteriorating the hemodynamic environment in coronary arteries.

A 0D-3D multi-scale model of the portal venous system coupled with the entire cardiovascular system applied to predict postsplenectomy hemodynamic metrics.

Splenectomy is a common surgery for portal hypertensive patients with splenomegaly. Although splenectomy is able to effectively relieve the complications of portal hypertension, it also increases the risk of portal venous system thrombosis remarkably. Previous studies demonstrated that the hemodynamic metrics of the portal venous system could be employed in predicting the risk of postsplenectomy thrombosis, and 3D models were utilized to simulate the blood flow in the portal venous system. Aiming to reflect the global effect of splenectomy and better simulate the hemodynamic metrics, in this study, a 0D-3D multi-scale model of the portal venous system coupled with the entire cardiovascular system was constructed based on population-averaged data in combination with patient-specific preoperative clinical measurements. The pre- and postoperative global blood flows as well as the variations were calculated successfully, and the flow field and time-averaged wall shear stress of the portal venous system were simulated. The model-simulated spatial distributions of the hemodynamic metrics in the portal venous system were comparable with the regions suffering from thrombosis after splenectomy. These results imply that the present model could reflect the reallocation of the blood flow in the splanchnic circulation after splenectomy and simulate the hemodynamic metrics of the portal venous system, which would promote the more accurate risk stratification of postsplenectomy thrombosis and improve the patient-specific postoperative management.Clinical Relevance- The computational model developed by the present study provides a feasible scheme for simulating postsplenectomy hemodynamic metrics of the portal venous system more accurately, which would benefit the risk prediction and prophylaxis of portal venous system thrombosis for portal hypertensive patients receiving splenectomy.

Microfluidics-enabled Serial Assembly of Lipid-siRNA-sorafenib Nanoparticles for Synergetic Hepatocellular Carcinoma Therapy.

Multi-component nanoparticles (mNPs) hold great potential for disease prevention and treatment. However, a major barrier is the lack of versatile platforms to accommodate steps of assembly processes of mNPs. Here the microfluidics-enabled serial assembly (MESA) of mNPs is presented. The microfluidic chip, as a mini-conveyor of initial materials, sequentially enables the assembly of sorafenib supramolecule, electrostatic adsorption of siRNA, and surface assembly of protective lipids. The produced lipid-siRNA-sorafenib nanoparticles (LSS NPs) have ultrahigh encapsulation efficiencies for sorafenib (≈100%) and siRNA (≈95%), which benefit from the accommodation of both fast and slow processes on the chip. Although carrying negative charges, LSS NPs enable cytosolic delivery of agents and high gene silencing efficiency within tumor cells. In vivo, the LSS NPs delivering hypoxia-induced factor (HIF1α)-targeted siRNA efficiently regress tumors of Hep3B xenograft and hepatocellular carcinoma patient-derived primary cells xenograft (PDCX) and finally extend the average survival of PDCX mice to 68 days. Thus, this strategy is promising as a sorafenib/siRNA combination therapy, and MESA can be a universal platform for fabricating complex nanosystems.

Transcriptomic Changes and satP Gene Function Analysis in Pasteurella multocida with Different Levels of Resistance to Enrofloxacin.

Pasteurella multocida (Pm) is one of the major pathogens of bovine respiratory disease (BRD), which can develop drug resistance to many of the commonly used antibiotics. Our earlier research group found that with clinical use of enrofloxacin, Pm was more likely to develop drug resistance to enrofloxacin. In order to better understand the resistance mechanism of Pm to enrofloxacin, we isolated PmS and PmR strains with the same PFGE typing in vitro, and artificially induced PmR to obtain the highly resistant phenotype, PmHR. Then transcriptome sequencing of clinically isolated sensitive strains, resistant and highly drug-resistant strains, treated with enrofloxacin at sub-inhibitory concentrations, were performed. The satP gene, of which the expression changed significantly with the increase in drug resistance, was screened. In order to further confirm the function of this gene, we constructed a satP deletion (ΔPm) strain using suicide vector plasmid pRE112, and constructed the C-Pm strain using pBBR1-MCS, and further analyzed the function of the satP gene. Through a continuously induced resistance test, it was found that the resistance rate of ΔPm was obviously lower than that of Pm in vitro. MDK99, agar diffusion and mutation frequency experiments showed significantly lower tolerance of ΔPm than the wild-type strains. The pathogenicity of ΔPm and Pm was measured by an acute pathogenicity test in mice, and it was found that the pathogenicity of ΔPm was reduced by about 400 times. Therefore, this study found that the satP gene was related to the tolerance and pathogenicity of Pm, and may be used as a target of enrofloxacin synergistic effect.

Genetic characterization of MDR genomic elements carrying two aac(6')-aph(2″) genes in feline-derived clinical Enterococcus faecalis isolate.

Multidrug-resistant Enterococcus faecalis (E. faecalis) often cause intestinal infections in cats. The aim of this study was to investigate a multidrug-resistant E. faecalis isolate for plasmidic and chromosomal antimicrobial resistance and their genetic environment. E. faecalis strain ESC1 was obtained from the feces of a cat. Antimicrobial susceptibility testing was carried out using the broth microdilution method. Conjugation experiments were performed using Escherichia coli and Staphylococcus aureus as receptors. Complete sequences of chromosomal DNA and plasmids were generated by whole genome sequencing (WGS) and bioinformatics analysis for the presence of drug resistance genes and mobile elements. Multidrug-resistant E. faecalis ESC1 contained a chromosome and three plasmids. The amino acid at position 80 of the parC gene on the chromosome was mutated from serine to isoleucine, and hence the amino acid mutation at this site led to the resistance of ESC1 strain to fluoroquinolones. Eleven antibiotic resistance genes were located on two plasmids. We identified a novel composite transposon carrying two aminoglycoside resistance genes aac(6')-aph(2″). This study reported the coexistence of a novel 5.4 kb composite transposon and a resistance plasmid with multiple homologous recombination in an isolate of E. faecalis ESC1. This data provides a basis for understanding the genomic signature and antimicrobial resistance mechanisms of this pathogen.

PGCLCs of human 45,XO reveal pathogenetic pathways of neurocognitive and psychosocial disorders.

BACKGROUND: Neurocognitive disorders and psychosocial difficulties are common in patients with Turner syndrome and multiple neurodegenerative diseases, yet there is no effective cure. Human primordial germ cells (hPGCs) are pluripotent germline stem cells in early embryo, which pass genetic information from one generation to the next, whereas all somatic cells will die along with the end of life. However, it is not known whether patient hPGCs with Turner syndrome contain information of neurocognitive and psychosocial illness. RESULTS: In this report, we used a high-density of culture system of embryoids derived from iPSCs of a patient with Turner syndrome to ask how pathogenetic pathways are associated with onset of neurocognitive and psychosocial disorders. The hPGC-Like Cells (hPGCLCs) were in vitro specified from iPSCs of 45,XO, 46,XX and 46,XY by the high-density induction of embryoids. Amazingly, we found that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched several common pathogenetic pathways regulating neurocognitive and psychosocial disorders, that shared among multiple neurodegenerative diseases and Turner syndrome. The downregulated chemical synaptic transmission pathways, including glutamatergic, GABAergic, and nicotine cholinergic synapses, indicated synaptic dysfunctions, while upregulated pathways that were associated with imbalance of mitochondrial respiratory chain complexes and apoptosis, may contribute to neuronal dysfunctions. Notably, downregulation of three types of ubiquitin ligases E1-E2-E3 and lysosome-associated sulfatases and RAB9A, owing to haploinsufficiency and parental preference of the X chromosome expression, indicated that two pathways of cellular degradation, lysosome and ubiquitin-proteasome, were impaired in the specification process of 45,XO hPGCLCs. This would lead to accumulation of undesired proteins and aggregates, which is a typically pathological hallmark in neurodegenerative diseases. CONCLUSIONS: Our data suggest that the specification process of the hPGCLCs in 45,XO, compared to those in 46,XX and 46,XY, enriched pathogenetic pathways that are associated with the onset of neurocognitive and psychosocial disorders.