CsPM5.2, a phosphate transporter protein-like gene, promotes powdery mildew resistance in cucumber.

Powdery mildew (PM) is one of the most serious fungal diseases affecting cucumbers (Cucumis sativus L.). The mechanism of PM resistance in cucumber is intricate and remains fragmentary as it is controlled by several genes. In this study, we detected the major-effect Quantitative Trait Locus (QTL), PM5.2, involved in PM resistance by QTL mapping. Through fine mapping, the dominant PM resistance gene, CsPM5.2, was cloned and its function was confirmed by transgenic complementation and natural variation identification. In cultivar 9930, a dysfunctional CsPM5.2 mutant resulted from a single nucleotide polymorphism in the coding region and endowed susceptibility to PM. CsPM5.2 encodes a phosphate transporter-like protein PHO1; H3. The expression of CsPM5.2 is ubiquitous and induced by the PM pathogen. In cucumber, both CsPM5.2 and Cspm5.1 (Csmlo1) are required for PM resistance. Transcriptome analysis suggested that the salicylic acid (SA) pathway may play an important role in CsPM5.2-mediated PM resistance. Our findings help parse the mechanisms of PM resistance and provide strategies for breeding PM-resistant cucumber cultivars.

Physiological and pathological functions of TMEM106B in neurodegenerative diseases.

As an integral lysosomal transmembrane protein, transmembrane protein 106B (TMEM106B) regulates several aspects of lysosomal function and is associated with neurodegenerative diseases. The TMEM106B gene mutations lead to lysosomal dysfunction and accelerate the pathological progression of Neurodegenerative diseases. Yet, the precise mechanism of TMEM106B in Neurodegenerative diseases remains unclear. Recently, different research teams discovered that TMEM106B is an amyloid protein and the C-terminal domain of TMEM106B forms amyloid fibrils in various Neurodegenerative diseases and normally elderly individuals. In this review, we discussed the physiological functions of TMEM106B. We also included TMEM106B gene mutations that cause neurodegenerative diseases. Finally, we summarized the identification and cryo-electronic microscopic structure of TMEM106B fibrils, and discussed the promising therapeutic strategies aimed at TMEM106B fibrils and the future directions for TMEM106B research in neurodegenerative diseases.

TRIM21/USP15 balances ACSL4 stability and the imatinib resistance of gastrointestinal stromal tumors.

BACKGROUND: Imatinib has become an exceptionally effective targeted drug for treating gastrointestinal stromal tumors (GISTs). Despite its efficacy, the resistance to imatinib is common in GIST patients, posing a significant challenge to the effective treatment. METHODS: The expression profiling of TRIM21, USP15, and ACSL4 in GIST patients was evaluated using Western blot and immunohistochemistry. To silence gene expression, shRNA was utilized. Biological function of TRIM21, USP15, and ACSL4 was examined through various methods, including resistance index calculation, colony formation, shRNA interference, and xenograft mouse model. The molecular mechanism of TRIM21 and USP15 in GIST was determined by conducting Western blot, co-immunoprecipitation, and quantitative real-time PCR (qPCR) analyses. RESULTS: Here we demonstrated that downregulation of ACSL4 is associated with imatinib (IM) resistance in GIST. Moreover, clinical data showed that higher levels of ACSL4 expression are positively correlated with favorable clinical outcomes. Mechanistic investigations further indicated that the reduced expression of ACSL4 in GIST is attributed to excessive protein degradation mediated by the E3 ligase TRIM21 and the deubiquitinase USP15. CONCLUSION: These findings demonstrate that the TRIM21 and USP15 control ACSL4 stability to maintain the IM sensitive/resistant status of GIST.

Carbon dots with enhanced red emission for ratiometric sensing and encryption applications.

The excitation-dependent emission properties of carbon dots (Cdots) are extensively reported, but their red emission is often weak, limiting their wider application. Here we introduce ethidium bromide, as a functional precursor with red emission, to enhance the red emission for Cdots, with comparable intensity at a broad wavelength range to multi-emission Cdots (M-Cdots). We found that Cdots prepared with ethidium bromide/ethylenediamine exhibited strong blue and red emission at 440 and 615 nm, with optimal excitation at 360 and 470 nm as M-Cdots, respectively, but the Cdots from single ethidium bromide (EB-Cdots) possessed weak red emission. M-Cdots exhibited a broad absorption band at 478 nm, but a band blue-shifted to 425 nm was observed for EB-Cdots, while no absorption was observed at 478-425 nm for the Cdots prepared with citric acid and ethylenediamine. Thus, we proposed that C=O and C=N formed a π-conjugation structure as the absorption band at 478 nm for the red emission of M-Cdots, as also confirmed with the excitation at 470 nm. Moreover, the π-conjugation structure is fragile and sensitive to harsh conditions, so red emission was difficult to observe for the Cdots prepared with citric acid/ethylenediamine or single ethidium bromide. M-Cdots possess two centers for blue and red emission with different structures. The dual emission was therefore used for ratiometric sensing with dichromate (Cr2O72-) and formaldehyde (HCHO) as the targets using the intensity ratio of the emissions at 615 and 440 nm. Due to the comparable intensity at a broad wavelength range, we designed encryption codes with five excitations at 360, 400, 420, 450, and 470 nm as the inputs, and the emission colors were used for information decoding. Thus, we determined why red emission was difficult to realize for Cdots, and our results could motivate the design of red-emission Cdots for extensive applications.

Association of SGLT2 inhibitor dapagliflozin with risks of acute kidney injury and all-cause mortality in acute myocardial infarction patients.

OBJECTIVE: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have well-documented effects in reducing hospitalization or cardiovascular mortality, while the association of SGLT2 inhibitor dapagliflozin (DAPA) and the risk of acute kidney injury (AKI) in acute myocardial infarction (AMI) patients has not been comprehensively investigated. Therefore, we aimed to assess the association between DAPA and AKI risk in AMI patients after percutaneous coronary intervention (PCI) therapy. METHODS: Using the Changzhou Acute Myocardial Infarction Registry database, we retrospectively included AMI patients from January 2017 to August 2021 and analyzed the risk of AKI and all-cause mortality after PCI therapy. The patients were divided into two groups according to the use of DAPA (DAPA group and Ctrl group). Patients in the DAPA group started to use DAPA after admission and continued its use during hospitalization and follow-up period. Baseline characteristics were balanced between the two groups with a propensity score matching (PSM) analysis. The outcome was AKI within 7 days after PCI and all-cause mortality during a follow-up of 2 years. Univariate and multivariate logistic regression analyses were used to assess the association between DAPA and AKI risk. RESULTS: A total of 1839 AMI patients undergoing PCI were enrolled. DAPA was used in 278 (15.1%) patients. Postoperative AKI occurred in 351 (19.1%) cases. A 1:1 PSM analysis was used to reduce confounding factors. The multivariate stepwise regression analysis showed that DAPA (odds ratio, OR 0.66; 95% confidence interval, CI 0.44-0.97; P = 0.036) was an independent protective factor in the entire cohort. After matching, the use of DAPA in AMI patients was independently associated with a decline of AKI risk (OR 0.32; 95% CI, 0.19-0.53; P < 0.001) after hospital admission. Meanwhile, there were significant differences in mortality between the DAPA group and Ctrl group (2.5% vs. 7.6%, P = 0.012). CONCLUSION: SGLT2 inhibitor DAPA was associated with lower risks of incident AKI and all-cause mortality in AMI patients after PCI therapy.

Association between triglyceride glucose and acute kidney injury in patients with acute myocardial infarction: a propensity score­matched analysis.

BACKGROUND: Acute kidney injury (AKI) in patients with acute myocardial infarction (AMI) often indicates a poor prognosis. OBJECTIVE: This study aimed to investigate the association between the TyG index and the risk of AKI in patients with AMI. METHODS: Data were taken from the Medical Information Mart for Intensive Care (MIMIC) database. A 1:3 propensity score (PS) was set to match patients in the AKI and non-AKI groups. Multivariate logistic regression analysis, restricted cubic spline (RCS) regression and subgroup analysis were performed to assess the association between TyG index and AKI. RESULTS: Totally, 1831 AMI patients were included, of which 302 (15.6%) had AKI. The TyG level was higher in AKI patients than in non-AKI patients (9.30 ± 0.71 mg/mL vs. 9.03 ± 0.73 mg/mL, P < 0.001). Compared to the lowest quartile of TyG levels, quartiles 3 or 4 had a higher risk of AKI, respectively (Odds Ratiomodel 4 = 2.139, 95% Confidence Interval: 1.382-3.310, for quartile 4 vs. quartile 1, Ptrend < 0.001). The risk of AKI increased by 34.4% when the TyG level increased by 1 S.D. (OR: 1.344, 95% CI: 1.150-1.570, P < 0.001). The TyG level was non-linearly associated with the risk of AKI in the population within a specified range. After 1:3 propensity score matching, the results were similar and the TyG level remained a risk factor for AKI in patients with AMI. CONCLUSION: High levels of TyG increase the risk of AKI in AMI patients. The TyG level is a predictor of AKI risk in AMI patients, and can be used for clinical management.

Development and validation of a novel combinatorial nomogram model to predict in-hospital deaths in heart failure patients.

BACKGROUND: The purpose of this study was to develop a Nomogram model to identify the risk of all-cause mortality during hospitalization in patients with heart failure (HF). METHODS: HF patients who had been registered in the Medical Information Mart for Intensive Care (MIMIC) III and IV databases were included. The primary outcome was the occurrence of all-cause mortality during hospitalization. Two Logistic Regression models (LR1 and LR2) were developed to predict in-hospital death for HF patients from the MIMIC-IV database. The MIMIC-III database were used for model validation. The area under the receiver operating characteristic curve (AUC) was used to compare the discrimination of each model. Calibration curve was used to assess the fit of each developed models. Decision curve analysis (DCA) was used to estimate the net benefit of the predictive model. RESULTS: A total of 16,908 HF patients were finally enrolled through screening, of whom 2,283 (13.5%) presented with in-hospital death. Totally, 48 variables were included and analyzed in the univariate and multifactorial regression analysis. The AUCs for the LR1 and LR2 models in the test cohort were 0.751 (95% CI: 0.735∼0.767) and 0.766 (95% CI: 0.751-0.781), respectively. Both LR models performed well in the calibration curve and DCA process. Nomogram and online risk assessment system were used as visualization of predictive models. CONCLUSION: A new risk prediction tool and an online risk assessment system were developed to predict mortality in HF patients, which performed well and might be used to guide clinical practice.

Development and validation of a simultaneous quantitative analytical method for two Alternaria toxins and their metabolites in plasma and urine using ultra-high-performance liquid chromatography-tandem mass spectrometry.

Much more attention has been paid to the contamination of Alternaria toxins because of food contamination and the threat to human health. In this study, an ultra-high-performance liquid chromatography-tandem mass spectrometry method was developed for the simultaneous detection of the prototypical alternariol, alternariol monomethylether, and the metabolites 4-oxhydryl alternariol, and alternariol monomethylether 3-sulfate ammonium salt of Alternaria toxins. The positive samples were used as matrix samples to optimize the different experimental conditions. 0.01% formic acid solution and acetonitrile were used as the mobile phase, and analytes were scanned in negative electron spray ionization under multiple reaction monitoring, and quantitative determination by isotope internal standard method. Application of this method to samples of human plasma and urine showed the detection of the above analytes. The results showed that the recoveries were from 80.40% to 116.4%, intra-day accuracy was between 0.6% and 8.0%, and inter-day accuracy was between 1.1% and 12.1%. The limit of detection of the four analytes ranged from 0.02 to 0.6 µg/L in urine, and 0.02 to 0.5 µg/L in plasma, respectively. Thus, the developed method was rapid and accurate for the simultaneous detection of analytes and provided a theoretical basis for the risk assessment of Alternaria toxins for human exposure.

Mapping and identification of CsSF4, a gene encoding a UDP-N-acetyl glucosamine-peptide N-acetylglucosaminyltransferase required for fruit elongation in cucumber (Cucumis sativus L.).

KEY MESSAGE: The short fruit length phenotype in sf4 is caused by a SNP in Csa1G665390, which encodes an O-linked N-acetylglucosamine (GlcNAc) transferase in cucumber. Cucumber fruit is an excellent resource for studying fruit morphology due to its fast growth rate and naturally abundant morphological variations. The regulatory mechanisms underlying plant organ size and shape are important and fundamental biological questions. In this study, a short-fruit length mutant, sf4, was identified from an ethyl methanesulfonate (EMS) mutagenesis population derived from the North China-type cucumber inbred line WD1. Genetic analysis indicated that the short fruit length phenotype of sf4 was controlled by a recessive nuclear gene. The SF4 locus was located in a 116.7-kb genomic region between the SNP markers GCSNP75 and GCSNP82 on chromosome 1. Genomic and cDNA sequences analysis indicated that a single G to A transition at the last nucleotide of Csa1G665390 intron 21 in sf4 changed the splice site from GT-AG to GT-AA, resulting in a 42-bp deletion in exon 22. Csa1G665390 is presumed to be a candidate gene, CsSF4 that encodes an O-linked N-acetylglucosamine (GlcNAc) transferase (OGT). CsSF4 was highly expressed in the leaves and male flowers of wild-type cucumbers. Transcriptome analysis indicated that sf4 had alterations in expression of many genes involved in hormone response pathways, cell cycle regulation, DNA replication, and cell division, suggesting that cell proliferation-associated gene networks regulate fruit development in cucumber. Identification of CsSF4 will contribute to elucidating the function of OGT in cell proliferation and to understanding fruit elongation mechanisms in cucumber.

Multifunctional Low-Generation Dendrimer Nanogels as an Emerging Probe for Tumor-Specific CT/MR Dual-Modal Imaging.

The development of nanoprobes that have amplified enhanced permeability and retention (EPR) effect is crucial for their precise cancer diagnosis performance. Here, we present the development of functional dendrimer-based nanogels (DNGs) with the generation three primary amine-terminated poly(amidoamine) (PAMAM) dendrimers (G3·NH2) cross-linked by N,N'-bis(acryloyl) cystamine (BAC). The DNGs were prepared through a Michael addition reaction between G3·NH2 dendrimers and BAC via an inverse microemulsion method and entrapped with gold nanoparticles (Au NPs) to form Au-DNGs. The Au-DNGs were sequentially modified with diethylenetriamine penta-acetic acid (DTPA)-gadolinium (Gd) complex, poly(ethylene glycol) (PEG)-linked arginine-glycine-aspartic (RGD) peptide, and 1,3-propanesultone (1,3-PS). The formed multifunctional RGD-Gd@Au-DNGs-PS (R-G@ADP) possessing an average diameter of 122 nm are colloidally stable and display a high X-ray attenuation coefficient, excellent r1 relaxivity (9.13 mM-1 s-1), desired protein resistance rendered by the zwitterionic modification, and cytocompatibility. With the targeting specificity mediated by RGD and the much better tumor penetration capability than the counterpart material of single dendrimer-entrapped Au NPs, the developed multifunctional R-G@ADP enable targeted and enhanced computed tomography (CT)/magnetic resonance (MR) dual-modal imaging of a pancreatic tumor model in vivo. The current work demonstrates a unique design of targeted and zwitterionic DNGs with prolonged blood circulation time as an emerging nanoprobe for specific tumor CT/MR imaging through amplified passive EPR effect.

Direct and indirect selenium speciation in biofortified wheat: A tale of two techniques.

Wheat can be biofortified with different inorganic selenium (Se) forms, selenite or selenate. The choice of Se source influences the physiological response of the plant and the Se metabolites produced. We looked at selenium uptake, distribution and metabolization in wheat exposed to selenite, selenate and a 1:1 molar mixture of both to determine the impact of each treatment on the Se speciation in roots, shoots, and grains. To achieve a comprehensive quantification of the Se species, the complementarity of high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry and X-ray absorption spectroscopy was exploited. This approach allowed the identification of the six main selenium species: selenomethionine, selenocysteine, selenocystine, selenite, selenate, and elemental selenium. The three treatments resulted in similar total selenium concentration in grains, 90-150 mg Se kg-1 , but produced different effects in the plant. Selenite enhanced root accumulation (66% of selenium) and induced the maximum toxicity, whereas selenate favored shoot translocation (46%). With the 1:1 mixture, selenium was distributed along the plant generating lower toxicity. Although all conditions resulted in >92% of organic selenium in the grain, selenate produced mainly C-Se-C forms, such as selenomethionine, while selenite (alone or in the mixture) enhanced the production of C-Se-Se-C forms, such as selenocystine, modifying the selenoamino acid composition. These results provide a better understanding of the metabolization of selenium species which is key to minimize plant toxicity and any concomitant effect that may arise due to Se-biofortification.

Dapagliflozin reduces risk of heart failure rehospitalization in diabetic acute myocardial infarction patients: a propensity score-matched analysis.

OBJECTIVE: The aim of this study was to investigate the effect of dapagliflozin (DAPA) on the rate of heart failure rehospitalization in patients with acute myocardial infarction (AMI) and type 2 diabetes mellitus (T2DM). METHODS: AMI patients with T2DM from CZ-AMI registry between January 2017 and January 2021 were enrolled in this study. Patients were stratified into DAPA users and non-DAPA users. The primary outcome was the incidence of heart failure rehospitalization. Kaplan-Meier analysis and Cox regressions were performed to evaluate the prognostic significance of DAPA. Propensity score matching (PSM) was performed to minimize the bias of confounding factors and facilitate the comparability between groups. The enrolled patients were matched with a propensity score of 1:1. RESULTS: A total of 961 patients were included, and 132 (13.74%) heart failure rehospitalizations occurred during a median follow-up of 540 days. In the Kaplan-Meier analysis, DAPA users had a statistically significantly lower rate of heart failure rehospitalization than non-DAPA users (p < 0.0001). Multivariate Cox analysis showed that DAPA was an independent protective factor for heart failure rehospitalization risk after discharge (HR = 0.498, 95% CI = 0.296 ~ 0.831, p = 0.001). After 1:1 propensity score matching, survival analysis showed a lower cumulative risk of heart failure rehospitalization in DAPA users than in non-DAPA users (p = 0.0007). In-hospital and continued use of DAPA remained significantly associated with a reduced risk of heart failure rehospitalization (HR = 0.417, 95% CI = 0.417 ~ 0.838, p = 0.001). Results were consistent across sensitivity and subgroup analyses. CONCLUSION: In patients with diabetic AMI, in-hospital and continued use of DAPA after discharge were associated with a significant lower risk of heart failure rehospitalization.

Comparison of the inoculum effect of in vitro antibacterial activity of Imipenem/relebactam and Ceftazidime/avibactam against ESBL-, KPC- and AmpC-producing Escherichia coli and Klebsiella pneumoniae.

OBJECTIVE: To evaluate effect of inoculum size of extended-spectrum ß-Lactamase (ESBL)-producing-, AmpC-producing-, and KPC-producing Escherichia coli and Klebsiella pneumoniae on the in vitro antibacterial effects of imipenem/relebactam (IMR) and ceftazidime/avibactam (CZA). METHODS: We compared the impact of inoculum size on IMR and CZA of sixteen clinical isolates and three standard isolates through antimicrobial susceptibility tests, time-kill assays and in vitro PK/PD studies. RESULTS: When inoculum size increased from 105 to 107 CFU/mL, an inoculum effect was observed for 26.3% (5/19) and 52.6% (10/19) of IMR and CZA, respectively; time-kill assays revealed that the concentration of CZA increased from ≥ 4 × MIC to 16 × MIC to reach 99.9% killing rate against K. pneumoniae ATCC-BAA 1705 (KPC-2-, OXA-9- and SHV-182-producing) and 60,700 (SHV-27- and DHA-1-producing). While for IMR, a concentration from 1 × MIC to 4 × MIC killed 99.9% of the four strains. When the inoculum size increased to 109 CFU/mL, neither IMR nor CZA showed a detectable antibacterial effect, even at a high concentration. An in vitro PK/PD study revealed a clear bactericidal effect when IMR administered as 1.25 g q6h when inoculum size increased. CONCLUSION: An inoculum effect on CZA was observed more frequent than that on IMR. Among the ß-lactamase-producing strains, the inoculum effect was most common for SHV-producing and KPC-producing strains.

Comparative transcription profiling of mRNA and lncRNA in pulmonary arterial hypertension after C75 treatment.

OBJECTIVES: To investigate mRNA and long non-coding RNA (lncRNA) expression profiles in monocrotaline (MCT)- mice. MATERIALS AND METHODS: Lung tissues (Control-Vehicle, MCT-Vehicle, and MCT-C75) were examined by high-throughput sequencing (HTS). Aberrantly expressed mRNAs and lncRNAs were analyzed by bioinformatics. Cell proliferation and cell cycle analysis were performed to detect the potential protective effects of C75, an inhibitor of fatty acid synthase. The signaling pathways associated with inflammatory responses were verified by real time-PCR. RESULTS: RNA sequencing data reveals 285 differentially expressed genes (DEGs) and 147 lncRNAs in the MCT-Vehicle group compared to the control. After five-week of C75 treatment, 514 DEGs and 84 lncRNAs are aberrant compared to the MCT-Vehicle group. Analysis of DEGs and lncRNA target genes reveals that they were enriched in pathways related to cell cycle, cell division, and vascular smooth muscle contraction that contributes to the PAH pathological process. Subsequently, the expression of eight DEGs and three lncRNAs is verified using RT-PCR. Differentially expressed lncRNAs (ENSMUSG00000110393.2, Gm38850, ENSMUSG00000100465.1, ENSMUSG00000110399.1) may associate in PAH pathogenesis as suggested by co-expression network analysis. C75 can protect against MCT-induced PAH through its anti-inflammatory and anti-proliferation. CONCLUSIONS: These DEGs and lncRNAs can be considered as novel candidate regulators of PAH pathogenesis. We propose that C75 treatment can partially reverse PAH pathogenesis through modulating cell cycle, cell proliferation, and anti-inflammatory.

Efficacy of Opioids in Preemptive Multimodal Analgesia for Total Knee Arthroplasty: A Prospective, Double-Blind, Placebo-Controlled, Randomized Trial.

BACKGROUND: Preemptive multimodal analgesia is a commonly used technique to control pain following total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of pre-emptive opioids for pain management in patients who underwent TKA. METHODS: In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients who underwent TKA at our hospital were randomized to the oxycodone or control group. At 2 hours before surgery, patients in the oxycodone group received 400 mg celecoxib, 150 mg pregabalin, and 10 mg extended-release oxycodone hydrochloride. Patients in the control group received 400 mg celecoxib, 150 mg pregabalin, and placebo. The primary outcome was postoperative consumption of morphine hydrochloride as rescue analgesia. Secondary outcomes were time to first rescue analgesia, postoperative pain assessed by the visual analogue scale, functional recovery assessed by range of knee motion and ambulation distance, time until hospital discharge, indicators of liver function, and complication rates. RESULTS: The 2 groups were similar in mean postoperative 0 to 24 hour morphine consumption (11.4 mg for control versus 12.4 mg for oxycodone group, P = .419) and mean total morphine consumption (18.2 versus 19.8 mg, P = .227). There were no statistical differences in secondary outcomes. CONCLUSIONS: In our study, preemptive opioid administration did not provide clinical benefits over placebo. Orthopaedic surgeons should consider not using pre-operative opioids in patients undergoing TKA.

Molecular epidemiology and change trend of methicillin-resistant Staphylococcus aureus from invasive infections of a hospital in Hangzhou from 2012 to 2018.

The disease caused by methicillin-resistant Staphylococcus aureus (MRSA) is a global public health challenge that threatens society and patients seriously. Therefore, the molecular epidemiology and change trend of MRSA is essential for the control and treatment of diseases caused by the pathogen in their regions. To explore molecular epidemiology of MRSA in Hangzhou, we collected 162 MRSA isolates from 2012 to 2018, conducted the antimicrobial susceptibility and used polymerase chain reaction(PCR) to test the molecular typing including multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec), staphylococcal protein A (spa A) and Panton-Valentine leucocidin (PVL). All the strains was divided into community-associated MRSA (CA-MRSA) or hospital-associated MRSA (HA-MRSA). 162 MRSA isolates were divided into 16 STs and 30 spa types. The major ST type was ST5 (96/162, 59.3%) and the predominant spa type was t311 (83/162, 51.2%). Five SCCmec types were found and the most common SCCmec type was type II (101/162, 61.7%). ST5-II-t311 was the predominant MRSA clone. And the prevalence of ST5 MRSA gradually declined from 2014 to 2018 but the prevalence of ST59 MRSA significantly increased. At the same time, livestock-associated methicillin-resistant Staphylococcus aureus(LA-MRSA) ST398 and ST9 were detected. Twenty-eight isolates were PVL gene positive (28/162, 17.3%). The most prevalent PVL-positive clone was ST59-IVa-t437. Comparing with HA-MRSA, CA-MRSA had a lower probability of ST5 (9.1% vs 67.1%, P=0.000) but a higher probability of ST59 (63.6% vs 11.4%, P=0.000), not only that, it was more likely to carrying PVL-positive gene (36.4% vs 14.3%, P=0.028). In summary, the molecular types of MRSA were getting complex over time. ST5-II-t311 was the predominant clone of MRSA isolate with a downward incidence from 2014 to 2018. ST59 MRSA strains, which is thought community related strain are spreading into hospitals and has an upward incidence from 2014 to 2018.

Role of cysteine in the improvement of γ-aminobutyric acid production by nonproteolytic Levilactobacillus brevis in coculture with Streptococcus thermophilus.

Previous research has showed that nonproteolytic Levilactobacillus brevis 145 (L) in coculture with Streptococcus thermophilus 1275 (S), not Lactobacillus delbrueckii ssp. bulgaricus (Lbu), was able to produce γ-aminobutyric acid (GABA) during milk fermentation in the presence of monosodium glutamate (MSG). It was assumed that differences of casein hydrolysis patterns between Strep. thermophilus 1275 and L. bulgaricus caused the phenomenon. Moreover, the GABA content was low and residual MSG was high in SL-fermented milk. In our research, comparison of peptide profiles determined by liquid chromatography/tandem mass spectrometry showed that αS2-casein, ß-casein, and κ-casein degradation by L. bulgaricus and Strep. thermophilus varied. Importantly, the peptide number in the L and Lbu coculture group increased compared with the Lbu monoculture group, whereas the peptide number in the SL coculture group decreased in comparison with S monoculture group, suggesting that L. bulgaricus was not able to provide peptides for the growth of Lb. brevis 145. Furthermore, we found that after supplementation with cysteine (50 mg/L) during milk fermentation by SL, 10 g/L MSG was converted into 4.8 g/L GABA with a minimum level of residual MSG, viable cell counts of Lb. brevis and lactic acid production were increased, and the casein hydrolysis pattern was not influenced. Moreover, sulfhydryl group-containing chemicals including cystine, reduced glutathione, and oxidized glutathione showed effects similar to that of cysteine in improving GABA production. Finally, when L. bulgaricus YIB2 was combined with SL, supplementation of cysteine was also able to significantly improve GABA production.

Cysteine protected cells from H2O2-induced damage and promoted long-chain fatty acids synthesis in vivo to improve γ-aminobutyric acid production in Levilactobacillus brevis.

Levilactobacillus brevis NPS-QW-145 isolated from kimchi is deficient in glutamate dehydrogenase-encoding gene (gdhA) to form glutamate, hence it required exogenous supplementation of glutamate/monosodium glutamate (MSG) for decarboxylation reaction to produce γ-aminobutyric acid (GABA). However, GABA conversion rate from MSG was relatively low. The individual effect of 20 amino acids on regulating GABA biosynthesis was investigated. Cysteine was selected to significantly improve GABA production from MSG. It was found that Lb. brevis was capable of producing H2O2, cysteine protected Lb. brevis against H2O2-induced oxidative damage to increase cell viability for the enhancement of GABA production. Moreover, cysteine promoted glucose consumption to produce acetyl-CoA for synthesizing long-chain fatty acids to significantly up-regulate GABA biosynthesis. These findings deciphered antioxidative capability of cysteine in Lb. brevis 145 and provided a theoretical basis for fatty acids synthesis-mediated GABA synthesis in Lb. brevis 145, and possibly in other lactic acid bacteria.

DNA methylation-mediated silencing of microRNA-204 enhances T cell acute lymphoblastic leukemia by up-regulating MMP-2 and MMP-9 via NF-κB.

T cell acute lymphoblastic leukaemia (T-ALL) is a highly aggressive haematological cancer of the bone marrow. The abnormal expression of microRNAs (miRNAs) is reportedly involved in T-ALL development and progression. Thus, we aimed to decipher the involvement of miR-204 silencing mediated by DNA methylation in the occurrence of T cell acute lymphoblastic leukaemia (T-ALL). miR-204 expression was determined in bone marrow and peripheral blood samples from T-ALL patients by real-time quantitative PCR (RT-qPCR) with its effect on cell proliferation evaluated by functional assays. In addition, bisulphite sequencing PCR was employed to detect the DNA methylation level of the miR-204 promoter region, and the binding site between miR-204 and IRAK1 was detected by luciferase assay. We found that miR-204 was down-regulated in T cells of T-ALL patients, which was caused by the increased DNA methylation in the promoter region of miR-204. Moreover, overexpression of miR-204 inhibited T-ALL cell proliferation while enhancing their apoptosis through interleukin receptor-associated kinase 1 (IRAK1), which enhanced the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9 through activation of p-p65. Thus, miR-204 modulated MMP-2 and MMP-9 through IRAK1/NF-κB signalling pathway, which was confirmed by in vivo assay. Taken together, DNA methylation-mediated miR-204 silencing increased the transcription of IRAK1, thus activating the NF-κB signalling pathway and up-regulating the downstream targets MMP-2/MMP-9.

Life-threatening arrhythmias with autosomal recessive TECRL variants.

AIMS: Sudden death and aborted sudden death have been observed in patients with biallelic variants in TECRL. However, phenotypes have only begun to be described and no data are available on medical therapy after long-term follow-up. METHODS AND RESULTS: An international, multi-centre retrospective review was conducted. We report new cases associated with TECRL variants and long-term follow-up from previously published cases. We present 10 cases and 37 asymptomatic heterozygous carriers. Median age at onset of cardiac symptoms was 8 years (range 1-22 years) and cases were followed for an average of 10.3 years (standard deviation 8.3), right censored by death in three cases. All patients on metoprolol, bisoprolol, or atenolol were transitioned to nadolol or propranolol due to failure of therapy. Phenotypes typical of both long QT syndrome and catecholaminergic polymorphic ventricular tachycardia (CPVT) were observed. We also observed divergent phenotypes in some cases despite identical homozygous variants. None of 37 heterozygous family members had a cardiac phenotype. CONCLUSION: Patients with biallelic pathogenic TECRL variants present with variable cardiac arrhythmia phenotypes, including those typical of long QT syndrome and CPVT. Nadolol and propranolol may be superior beta-blockers in this setting. No cardiac disease or sudden death was present in patients with a heterozygous genotype.