Involvement of the YneS/YgiH and PlsX proteins in phospholipid biosynthesis in both Bacillus subtilis and Escherichia coli

<p>Abstract</p> <p>Background</p> <p>Phospholipid biosynthesis commences with the acylation of glycerol-3-phosphate (G3P) to form 1-acyl-G3P. This step is catalyzed by the PlsB protein in <it>Escherichia coli</it>. The gene encoding this protein has not been identified, however, in the majority of bacterial genome sequences, including that of <it>Bacillus subtilis</it>. Recently, a new two-step pathway catalyzed by PlsX and PlsY proteins for the initiation of phospholipid formation in <it>Streptococcus pneumoniae </it>has been reported.</p> <p>Results</p> <p>In <it>B. subtilis</it>, 271 genes have been reported to be indispensable, when inactivated singly, for growth in LB medium. Among these, 11 genes encode proteins with unknown functions. As part of a genetic study to identify the functions of these genes, we show here that the <it>B. subtilis </it>ortholog of <it>S. pneumoniae </it>PlsY, YneS, is required for G3P acyltransferase activity, together with PlsX. The <it>B. subtilis </it>genome lacks <it>plsB</it>, and we show in vivo that the PlsX/Y pathway is indeed essential for the growth of bacteria lacking <it>plsB</it>. Interestingly, in addition to <it>plsB</it>, <it>E. coli </it>possesses <it>plsX </it>and the <it>plsY </it>ortholog, <it>ygiH</it>. We therefore explored the functional relationship between PlsB, PlsX and YgiH in <it>E. coli</it>, and found that <it>plsB </it>is essential for <it>E. coli </it>growth, indicating that PlsB plays an important role in 1-acyl-G3P synthesis in <it>E. coli</it>. We also found, however, that the simultaneous inactivation of <it>plsX </it>and <it>ygiH </it>was impossible, revealing important roles for PlsX and YgiH in <it>E. coli </it>growth.</p> <p>Conclusion</p> <p>Both <it>plsX </it>and <it>yneS </it>are essential for 1-acyl-G3P synthesis in <it>B. subtilis</it>, in agreement with recent reports on their biochemical functions. In <it>E. coli</it>, PlsB plays a principal role in 1-acyl-G3P synthesis and is also essential for bacterial growth. PlsX and YgiH also, however, play important roles in <it>E. coli </it>growth, possibly by regulating the intracellular concentration of acyl-ACP. These proteins are therefore important targets for development of new antibacterial agents.</p

BALB/c-Fcgr2b−/−Pdcd1−/− mouse expressing anti-urothelial antibody is a novel model of autoimmune cystitis

We report the impact of anti-urothelial autoantibody (AUAb) on urinary bladder phenotype in BALB/c mice deficient of the FcγRIIb and PD-1. AUAb was present in serum samples from approximately half of the double-knockout (DKO) mice, as detected by immunofluorescence and immunoblots for urothelial proteins including uroplakin IIIa. The AUAb-positive DKO mice showed degeneration of urothelial plaque and umbrella cells, along with infiltration of inflammatory cells in the suburothelial layer. TNFα and IL-1β were upregulated in the bladder and the urine of AUAb-positive DKO mice. Voiding behavior of mice was analyzed by the Voided Stain on Paper method. 10-week-old and older AUAb-positive DKO mice voided significantly less urine per void than did wild type (WT) mice. Furthermore, administration of the AUAb-containing serum to WT mice significantly reduced their urine volume per void. In summary, this report presents a novel comprehensive mouse model of autoimmune cystitis

Regulation of chromosomal replication initiation by oriC-proximal DnaA-box clusters in Bacillus subtilis

Bacterial chromosome replication is initiated by binding of DnaA to a DnaA-box cluster (DBC) within the replication origin (oriC). In Bacillus subtilis, six additional DBCs are found outside of oriC and some are known to be involved in transcriptional regulation of neighboring genes. A deletion mutant lacking the six DBCs (Δ6) initiated replication early. Further, inactivation of spo0J in Δ6 cells yielded a pleiotropic phenotype, accompanied by severe growth inhibition. However, a spontaneous suppressor in soj or a deletion of soj, which stimulates DnaA activity in the absence of Spo0J, counteracted these effects. Such abnormal phenotypic features were not observed in a mutant background in which replication initiation was driven by a plasmid-derived replication origin. Moreover, introduction of a single DBC at various ectopic positions within the Δ6 chromosome partly suppressed the early-initiation phenotype, but this was dependent on insertion location. We propose that DBCs negatively regulate replication initiation by interacting with DnaA molecules and play a major role, together with Spo0J/Soj, in regulating the activity of DnaA

Distribution of Stable DnaA-Binding Sites on the Bacillus Subtilis Genome Detected using a Modified ChIP-chip Method

We developed a modified ChIP-chip method, designated ChAP-chip (Chromatin Affinity Precipitation coupled with tiling chip). The binding sites of Bacillus subtilis Spo0J determined using this technique were consistent with previous findings. A DNA replication initiator protein, DnaA, formed stable complexes at eight intergenic regions on the B. subtilis genome. Characterization of the binding sequences suggested that two factors—the local density of DnaA boxes and their affinities for DnaA—are critical for stable binding. We further showed that in addition to autoregulation, DnaA directly modulate the expression of sda in a positive, and ywlC and yydA in a negative manner. Examination of possible stable DnaA-binding sequences in other Bacillus species suggested that DnaA-dependent regulation of those genes is maintained in most bacteria examined, supporting their biological significance. In addition, a possible stable DnaA-binding site downstream of gcp is also suggested to be conserved. Furthermore, potential DnaA-binding sequences specific for each bacterium have been identified, generally in close proximity to oriC. These findings suggest that DnaA plays several additional roles, such as control of the level of effective initiator, ATP-DnaA, and/or stabilization of the domain structure of the genome around oriC for the proper initiation of chromosome replication

Association between initial body temperature on hospital arrival and neurological outcome among patients with out-of-hospital cardiac arrest: a multicenter cohort study (the CRITICAL study in Osaka, Japan)

[Background] The association between spontaneous initial body temperature on hospital arrival and neurological outcomes has not been sufficiently studied in patients after out-of-hospital cardiac arrest (OHCA). [Methods] From the prospective database of the Comprehensive Registry of Intensive Care for OHCA Survival (CRITICAL) study in Osaka, Japan, we enrolled all patients with OHCA of medical origin aged > 18 years for whom resuscitation was attempted and who were transported to participating hospitals between 2012 and 2019. We excluded patients who were not witnessed by bystanders and treated by a doctor car or helicopter, which is a car/helicopter with a physician. The patients were categorized into three groups according to their temperature on hospital arrival: ≤35.9 °C, 36.0–36.9 °C (normothermia), and ≥ 37.0 °C. The primary outcome was 1-month survival, with a cerebral performance category of 1 or 2. Multivariable logistic regression analyses were performed to evaluate the association between temperature and outcomes (normothermia was used as the reference). We also assessed this association using cubic spline regression analysis. [Results] Of the 18, 379 patients in our database, 5014 witnessed adult OHCA patients of medical origin from 16 hospitals were included. When analyzing 3318 patients, OHCA patients with an initial body temperature of ≥37.0 °C upon hospital arrival were associated with decreased favorable neurological outcomes (6.6% [19/286] odds ratio, 0.51; 95% confidence interval, 0.27–0.95) compared to patients with normothermia (16.4% [180/1100]), whereas those with an initial body temperature of ≤35.9 °C were not associated with decreased favorable neurological outcomes (11.1% [214/1932]; odds ratio, 0.78; 95% confidence interval, 0.56–1.07). The cubic regression splines demonstrated that a higher body temperature on arrival was associated with decreased favorable neurological outcomes, and a lower body temperature was not associated with decreased favorable neurological outcomes. [Conclusions] In adult patients with OHCA of medical origin, a higher body temperature on arrival was associated with decreased favorable neurologic outcomes

Clustering out-of-hospital cardiac arrest patients with non-shockable rhythm by machine learning latent class analysis

[Aim] We aimed to identify subphenotypes among patients with out-of-hospital cardiac arrest (OHCA) with initial non-shockable rhythm by applying machine learning latent class analysis and examining the associations between subphenotypes and neurological outcomes. [Methods] This study was a retrospective analysis within a multi-institutional prospective observational cohort study of OHCA patients in Osaka, Japan (the CRITICAL study). The data of adult OHCA patients with medical causes and initial non-shockable rhythm presenting with OHCA between 2012 and 2016 were included in machine learning latent class analysis models, which identified subphenotypes, and patients who presented in 2017 were included in a dataset validating the subphenotypes. We investigated associations between subphenotypes and 30-day neurological outcomes. [Results] Among the 12, 594 patients in the CRITICAL study database, 4, 849 were included in the dataset used to classify subphenotypes (median age: 75 years, 60.2% male), and 1, 465 were included in the validation dataset (median age: 76 years, 59.0% male). Latent class analysis identified four subphenotypes. Odds ratios and 95% confidence intervals for a favorable 30-day neurological outcome among patients with these subphenotypes, using group 4 for comparison, were as follows; group 1, 0.01 (0.001–0.046); group 2, 0.097 (0.051–0.171); and group 3, 0.175 (0.073–0.358). Associations between subphenotypes and 30-day neurological outcomes were validated using the validation dataset. [Conclusion] We identified four subphenotypes of OHCA patients with initial non-shockable rhythm. These patient subgroups presented with different characteristics associated with 30-day survival and neurological outcomes

Association between serum lactate level during cardiopulmonary resuscitation and survival in adult out-of-hospital cardiac arrest: a multicenter cohort study

We aimed to investigate the association between serum lactate levels during cardiopulmonary resuscitation (CPR) and survival in patients with out-of-hospital cardiac arrest (OHCA). From the database of a multicenter registry on OHCA patients, we included adult nontraumatic OHCA patients transported to the hospital with ongoing CPR. Based on the serum lactate levels during CPR, the patients were divided into four quartiles: Q1 (≤ 10.6 mEq/L), Q2 (10.6–14.1 mEq/L), Q3 (14.1–18.0 mEq/L), and Q4 (> 18.0 mEq/L). The primary outcome was 1-month survival. Among 5226 eligible patients, the Q1 group had the highest 1-month survival (5.6% [74/1311]), followed by Q2 (3.6% [47/1316]), Q3 (1.7% [22/1292]), and Q4 (1.0% [13/1307]) groups. In the multivariable logistic regression analysis, the adjusted odds ratio of Q4 compared with Q1 for 1-month survival was 0.24 (95% CI 0.13–0.46). 1-month survival decreased in a stepwise manner as the quartiles increased (p for trend < 0.001). In subgroup analysis, there was an interaction between initial rhythm and survival (p for interaction < 0.001); 1-month survival of patients with a non-shockable rhythm decreased when the lactate levels increased (p for trend < 0.001), but not in patients with a shockable rhythm (p for trend = 0.72). In conclusion, high serum lactate level during CPR was associated with poor 1-month survival in OHCA patients, especially in patients with non-shockable rhythm

In-hospital extracorporeal cardiopulmonary resuscitation for patients with out-of-hospital cardiac arrest: an analysis by time-dependent propensity score matching using a nationwide database in Japan

院外心停止患者における膜型人工肺を活用した蘇生 --膜型人工肺を活用した蘇生と生存率向上との関連--. 京都大学プレスリリース. 2023-11-21.BACKGROUND: Extracorporeal cardiopulmonary resuscitation (ECPR) has been proposed as a rescue therapy for patients with refractory cardiac arrest. This study aimed to evaluate the association between ECPR and clinical outcomes among patients with out-of-hospital cardiac arrest (OHCA) using risk-set matching with a time-dependent propensity score. METHODS: This was a secondary analysis of the JAAM-OHCA registry data, a nationwide multicenter prospective study of patients with OHCA, from June 2014 and December 2019, that included adults (≥ 18 years) with OHCA. Initial cardiac rhythm was classified as shockable and non-shockable. Patients who received ECPR were sequentially matched with the control, within the same time (minutes) based on time-dependent propensity scores calculated from potential confounders. The odds ratios with 95% confidence intervals (CI) for 30-day survival and 30-day favorable neurological outcomes were estimated for ECPR cases using a conditional logistic model. RESULTS: Of 57, 754 patients in the JAAM-OHCA registry, we selected 1826 patients with an initial shockable rhythm (treated with ECPR, n = 913 and control, n = 913) and a cohort of 740 patients with an initial non-shockable rhythm (treated with ECPR, n = 370 and control, n = 370). In these matched cohorts, the odds ratio for 30-day survival in the ECPR group was 1.76 [95%CI 1.38-2.25] for shockable rhythm and 5.37 [95%CI 2.53-11.43] for non-shockable rhythm, compared to controls. For favorable neurological outcomes, the odds ratio in the ECPR group was 1.11 [95%CI 0.82-1.49] for shockable rhythm and 4.25 [95%CI 1.43-12.63] for non-shockable rhythm, compared to controls. CONCLUSION: ECPR was associated with increased 30-day survival in patients with OHCA with initial shockable and even non-shockable rhythms. Further research is warranted to investigate the reproducibility of the results and who is the best candidate for ECPR