Analysis of the Relationship Between the Changes of Serum SAA, LP-PLA2, sCD40L and Carotid Atherosclerosis Plaque in Patients with Acute Cerebral Infarction.

Objective: To explore the relationship between Serum amyloid protein A(SAA), lipoprotein-associated Phospholipase A2 (Lp-PLA2) and soluble CD40 ligand (sCD40L) in detecting the stability of carotid Atherosclerosis plaque. Methods: We examined 90 patients admitted to our hospital with acute cerebral infarction from July 2020 to December 2022. Carotid artery ultrasounds were performed for all of them. These patients were then divided into two groups: the stable plaque group (45 cases) and the unstable plaque group (45 cases), based on the ultrasound results. Additionally, we included a control group of 30 healthy individuals from our hospital. We collected fasting blood samples from the patients upon admission and used enzyme-linked immunosorbent assays to measure the mass concentrations of sCD40L, Lp-PLA2, and SAA in their serum. The results of these biomarkers were compared and analyzed to assess potential associations with plaque stability in patients with cerebral infarction. Results: Comparison of general clinical data and laboratory data: except for High-density lipoprotein, there was a statistical difference between the control group and the cerebral infarction group (P < .05), there was no statistical difference in gender, smoking history, drinking history and age (P > .05). Compared with the control group, the mass concentrations of sCD40L, Lp-PLA2, and SAA in patients with stable and unstable plaques increased significantly (P < .05); Compared with the stable plaque group, the mass concentrations of sCD40L, Lp-PLA2, and SAA in unstable plaque patients increased with statistical significance (P < .05). Correlation analysis shows that the mass concentrations of sCD40L, Lp-PLA2, and SAA are positively correlated with the stability of carotid artery plaques. SCD40L, Lp-PLA2 and SAA have certain diagnostic significance in the subject's working characteristic curve (Receiver operating characteristic) as a marker molecule for the diagnosis of unstable plaque. sCD40L (AUC=0.883) has more diagnostic value than SAA (AUC=0.756) and Lp-PLA2 (AUC=0.826). A binary logistic regression analysis was conducted using the stability of carotid artery plaques as the dependent variable and sCD40L, Lp-PLA2, and SAA as independent variables. The results showed that elevated serum sCD40L, Lp-PLA2, and SAA were independent risk factors for unstable carotid artery plaques (P < .05). Conclusion: The concentrations of sCD40L, Lp-PLA2 and SAA are closely related to the formation and type of carotid Atherosclerosis plaque in patients with acute cerebral infarction. This has potentially important clinical implications for the management and prevention of cardiovascular disease.

Utility of serum nuclear factor erythroid 2-related factor 2 as a potential prognostic biomarker of severe traumatic brain injury in adults: A prospective cohort study.

Objective: Nuclear factor erythroid 2-related factor 2 (Nrf2) may harbor endogenous neuroprotective role. We strived to ascertain the prognostic significance of serum Nrf2 in severe traumatic brain injury (sTBI). Methods: This prospective cohort study included 105 controls and 105 sTBI patients, whose serum Nrf2 levels were quantified. Its relations to traumatic severity and 180-day overall survival, mortality, and poor prognosis (extended Glasgow Outcome Scale score 1-4) were discerned using multivariate analysis. Results: There was a substantial enhancement of serum Nrf1 levels of patients (median, 10.9 vs. 3.3 ng/ml; P < 0.001), as compared to controls. Serum Nrf2 levels were independently correlative to Rotterdam computed tomography (CT) scores (ρ = 0.549, P < 0.001; t = 2.671, P = 0.009) and Glasgow Coma Scale (GCS) scores (ρ = -0.625, P < 0.001; t = -3.821, P < 0.001). Serum Nrf2 levels were significantly higher in non-survivors than in survivors (median, 12.9 vs. 10.3 ng/ml; P < 0.001) and in poor prognosis patients than in good prognosis patients (median, 12.5 vs. 9.4 ng/ml; P < 0.001). Patients with serum Nrf2 levels > median value (10.9 ng/ml) had markedly shorter 180-day overall survival time than the other remainders (mean, 129.3 vs. 161.3 days; P = 0.002). Serum Nrf2 levels were independently predictive of 180-day mortality (odds ratio, 1.361; P = 0.024), overall survival (hazard ratio, 1.214; P = 0.013), and poor prognosis (odds ratio, 1.329; P = 0.023). Serum Nrf2 levels distinguished the risks of 180-day mortality and poor prognosis with areas under receiver operating characteristic curve (AUCs) at 0.768 and 0.793, respectively. Serum Nrf2 levels > 10.3 ng/ml and 10.8 ng/ml discriminated patients at risk of 180-day mortality and poor prognosis with the maximum Youden indices of 0.404 and 0.455, respectively. Serum Nrf2 levels combined with GCS scores and Rotterdam CT scores for death prediction (AUC, 0.897; 95% CI, 0.837-0.957) had significantly higher AUC than GCS scores (P = 0.028), Rotterdam CT scores (P = 0.007), or serum Nrf2 levels (P = 0.006) alone, and the combination for poor outcome prediction (AUC, 0.889; 95% CI, 0.831-0.948) displayed significantly higher AUC than GCS scores (P = 0.035), Rotterdam CT scores (P = 0.006), or serum Nrf2 levels (P = 0.008) alone. Conclusion: Increased serum Nrf2 levels are tightly associated with traumatic severity and prognosis, supporting the considerable prognostic role of serum Nrf2 in sTBI.

Cerebrospinal fluid exosomal miR-152-3p predicts the occurrence of subarachnoid haemorrhage and regulates vascular smooth muscle cell dysfunction.

INTRODUCTION: Ruptured intracranial aneurysm (RA) can lead to subarachnoid haemorrhage (SAH). This study was to explore the predictive value of cerebrospinal fluid (CSF) derived exosome miR-152-3p and its regulatory role in the human vascular smooth muscle cells (HVSMCs). MATERIAL AND METHODS: Real-time quantitative polymerase reaction was carried out to detect CSF exosome miR-152-3p in 66 patients with unruptured intracranial aneurysms (UA), 69 patients with RA, and 68 patients with hydrocephalus. Clinical predictive value of SAH occurrence was assessed using receiver operating characteristic curve (ROC) and logistics regression analysis. Cell Counting Kit-8 and Transwell were employed to detect the proliferation and migration of HVSMCs. The binding relationship between miR-152-3p and PTEN was confirmed by the dual-luciferase reporter assay. RESULTS: Compared with hydrocephalus, exosome miR-152-3p was lower in patients with intracranial aneurysms, and among them, RA was lower than in patients with UA (p < 0.001). ROC confirmed that exosome miR-152-3p not only distinguishes patients with UA from patients with hydrocephalus but also predicts SAH in patients with intracranial aneurysms. Logistic regression analysis showed that miR-152-3p (OR = 0.039, 95% CI = 0.015-0.106, p < 0.001) and aneurysm size (OR = 2.701, 95% CI = 1.045-6.890, p = 0.040) were independent predictors of progression for UA to RA. Increased miR-152-3p inhibited the proliferation and migration of HVSMCs. PTEN was the direct target gene of miR-152-3p, which was elevated in CSF-derived exosomes and negatively correlated with miR-152-3p levels. CONCLUSIONS: Our study confirmed that the CSF-derived exosome miR-152-3p was a feasible predictor of SAH and was involved in the dysfunction of HVSMCs.

Predictive Value of Insulin Resistance as Determined by Homeostasis Model Assessment in Acute Ischemic Stroke Patients: A Systematic Review and Meta-Analysis.

Studies on association between homeostasis model assessment of insulin resistance (HOMA-IR) and adverse outcomes have yielded conflicting results in patients with acute ischemic stroke (AIS). This meta-analysis aimed to assess the predictive value of HOMA-IR in AIS patients. Two authors comprehensively searched PubMed and Embase databases until February 28, 2021. All observational studies investigating the association between HOMA-IR and adverse outcomes in AIS patients were included. Outcome measures were poor functional outcome (Modified Rankin Scale≥3), all-cause mortality, stroke recurrence, and neurologic worsening. Seven studies (eight articles) involving 8330 AIS patients were identified. For the highest versus lowest HOMA-IR, the pooled risk ratio (RR) of poor functional outcome was 2.55 (95% CI 1.76-3.70) after adjustment of conventional confounding factors. In addition, elevated HOMA-IR was associated with higher risk of neurologic worsening (RR 1.93; 95% CI 1.15-3.26). However, there were conflicting findings on the association of HOMA-IR with stroke recurrence and all-cause mortality. This meta-analysis confirms that HOMA-IR is significantly associated with an increased risk of poor functional outcome in patients with AIS. However, interpretation of the results of mortality, stroke recurrence, and neurologic worsening should be done with caution due to small number of studies available.

DepR1, a TetR Family Transcriptional Regulator, Positively Regulates Daptomycin Production in an Industrial Producer, Streptomyces roseosporus SW0702.

Daptomycin is a potent cyclic lipopeptide antibiotic. It is widely used against various Gram-positive bacterial pathogens. Historically, a poor understanding of the transcriptional regulation of daptomycin biosynthesis has limited the options for targeted genetic engineering toward titer improvement. Here, we isolated a TetR family transcriptional regulator, DepR1, from the industrial producer Streptomyces roseosporus SW0702 using a biotinylated dptE promoter (dptEp) as a probe. The direct interaction between DepR1 and dptEp then was confirmed by electrophoretic mobility shift assays and DNase I footprinting assays. The deletion of depR1 led to a reduction in dptEp activity and the cessation of daptomycin production. The ΔdepR1 mutant produced less red pigment and failed to sporulate on R5 medium. This suggests that DepR1 plays a positive role in the control of morphological differentiation. Moreover, DepR1 was positively autoregulated by directly binding to its own promoter. This might account for the positive feedback regulation of daptomycin production. Based on these positive effects, genetic engineering by overexpression of depR1 raised daptomycin production and shortened the fermentation period both in flask and in fermentor.

Transcriptional regulation of the daptomycin gene cluster in Streptomyces roseosporus by an autoregulator, AtrA.

Daptomycin is a cyclic lipopeptide antibiotic produced by Streptomyces roseosporus. To reveal the transcriptional regulatory mechanism of daptomycin biosynthesis, we used the biotinylated dptE promoter (dptEp) as a probe to affinity isolate the dptEp-interactive protein AtrA, a TetR family transcriptional regulator, from the proteome of mycelia. AtrA bound directly to dptEp to positively regulate gene cluster expression and daptomycin production. Meanwhile, both ΔatrA and ΔadpA mutants showed bald phenotype and null production of daptomycin. AdpA positively regulated atrA expression by direct interaction with atrA promoter (atrAp), and removal of ArpA in S. roseosporus, a homolog of the A-factor receptor, resulted in accelerated morphological development and increased daptomycin production, suggesting that atrA was the target of AdpA to mediate the A-factor signaling pathway. Furthermore, AtrA was positively autoregulated by binding to its own promoter atrAp. Thus, for the first time at the transcriptional level, we have identified an autoregulator, AtrA, that directly mediates the A-factor signaling pathway to regulate the proper production of daptomycin.

Proteasome involvement in a complex cascade mediating SigT degradation during differentiation of Streptomyces coelicolor.

In Streptomyces coelicolor, the ECF sigma factor SigT negatively regulates cell differentiation, and is degraded by ClpP protease in a dual positive feedback manner. Here we further report that the proteasome is required for degradation of SigT, but not for degradation of its anti-sigma factor RstA, and RstA can protect SigT from degradation independent of the proteasome. Meanwhile, deletion of the proteasome showed reduced production of secondary metabolites, and the fermentation medium from wild type could promote SigT degradation. Furthermore, overexpression of redD or actII-orf4 in the proteasome-deficiency mutant resulted in SigT degradation and over-production of both undecylprodigiosin and actinorhodin. Therefore the proteasome is required for SigT degradation by affecting the production of secondary metabolites during cell differentiation.