We constructed several recombinant Escherichia coli strains to transform phosphoenolpyruvate: carbohydrate phosphotransferase system (PTS system) and compared the characteristics of growth and metabolism of the mutants. We knocked-out the key genes ptsI and ptsG in PTS system by using Red homologous recombination in E. coli and meanwhile we also knocked-in the glucose facilitator gene glf from Zymomonas mobilis in the E. coli chromosome. Recombinant E. coli strains were constructed and the effects of cell growth, glucose consumption and acetic acid accumulation were also evaluated in all recombinant strains. The deletion of gene ptsG and ptsI inactivated some PTS system functions and inhibited the growth ability of the cell. Expressing the gene glf can help recombinant E. coli strains re-absorb the glucose through Glf-Glk (glucose facilitator-glucokinase) pathway as it can use ATP to phosphorylate glucose and transport into cell. This pathway can improve the availability of glucose and also reduce the accumulation of acetic acid; it can also broaden the carbon flux in the metabolism pathway.
Biological Transport ; Escherichia coli ; enzymology ; genetics ; Gene Deletion ; Gene Knock-In Techniques ; Gene Knockout Techniques ; Glucose ; metabolism ; Phosphoenolpyruvate Sugar Phosphotransferase System ; genetics ; Zymomonas ; genetics

Objective:To investigate the predictive value of thrombus permeability for poor outcome and symptomatic intracranial hemorrhage (sICH) after endovascular therapy (EVT) in patients with middle cerebral artery occlusion stroke.Methods:Patients with middle cerebral artery occlusion stroke underwent EVT at the Cardiocerebrovascular Disease Hospital, the Affiliated Hospital of Yan'an University from January 2018 to January 2024 were included retrospectively. Thrombus attenuation increase (TAI) was used to evaluate thrombus permeability. The poor outcome was defined as a modified Rankin Scale score >2 at 90 days after procedure. sICH was defined as an increase of ≥4 of the National Institutes of Health Stroke Scale (NIHSS) score relative to baseline or lowest within 7 days after EVT, and CT scan showed cerebral hemorrhage. Multivariate logistic regression analysis was used to determine the independent influencing factors of poor outcome and sICH. Receiver operating characteristic (ROC) curves was used to evaluate the predictive value of TAI for poor outcome and sICH. Results:A total of 77 patients with middle cerebral artery occlusion stroke received EVT treatment were enrolled, including 44 males (57.1%), aged 62.1±12.4 years. Thirty-three patients (48.1%) had poor outcome, 35 (45.5%) experienced hemorrhagic transformation, of which 12 (15.6%) were sICH. Multivariate logistic regression analysis showed that TAI (odds ratio [ OR] 0.930, 95% confidence interval [ CI] 0.883-0.980; P=0.007) and sICH ( OR 0.868, 95% CI 0.784-0.961; P=0.006) were the independent influencing factors of poor outcome. ROC curve analysis showed that the area under the curve of TAI for predicting poor outcome at 90 days was 0.836 (95% CI 0.742-0.930). The cut-off value was 10.135 HU. The sensitivity and specificity were 73.0% and 92.5%, respectively. The area under the curve of TAI for predicting sICH was 0.750 (95% CI 0.637-0.902). The cut-off value was 18.200 HU. The sensitivity and specificity were 94.1% and 64.5%, respectively. Conclusions:TAI has certain predictive value for poor outcome and sICH after EVT in patients with middle cerebral artery occlusion stroke. Patients with higher thrombus permeability are less likely to develop sICH after EVT and have a higher likelihood of good outcome.