Risk Prediction Models for Invasive Mechanical Ventilation in Patients with Autoimmune Encephalitis: A Retrospective Cohort Study.

Methods: A multivariate predictive nomogram model was developed using the risk factors identified by LASSO regression and assessed by receiver operator characteristics (ROC) curve, calibration curve, and decision curve analysis. Results: The risk factors predictive of severe respiratory failure were male gender, impaired hepatic function, elevated intracranial pressure, and higher neuron-specific enolase. The final nomogram achieved an AUC of 0.770. After validation by bootstrapping, a concordance index of 0.748 was achieved. Conclusions: Our nomogram accurately predicted the risk of developing respiratory failure needing IMV in AE patients and provide clinicians with a simple and effective tool to guide treatment interventions in the AE patients.

Ursolic Acid Ameliorated Neuronal Damage by Restoring Microglia-Activated MMP/TIMP Imbalance in vitro.

Purpose: The oxygen and glucose deprivation-reoxygenation (OGDR) model is widely used to evaluate ischemic stroke and cerebral ischemia-reperfusion (I/R) injury in vitro. Excessively activated microglia produce pro-inflammatory mediators such as matrix metalloproteinases [MMPs] and their specific inhibitors, tissue inhibitors of metalloproteinases [TIMPs], causing neuronal damage. Ursolic acid (UA) acts as a neuroprotective agent in the rat middle cerebral artery occlusion/reperfusion (MCAO/R) model keeping the MMP/TIMP balance with underlying mechanisms unclear. Our study used OGDR model to determine whether and how UA reduces neuronal damage by reversing MMP/TIMP imbalance caused by microglia in I/R injury in vitro. Methods: SH-SY5Y cells were first cultured with 95% N2 and 5% CO2 and then cultivated regularly for OGDR model. Cell viability was tested for a proper UA dose. We established a co-culture system with SH-SY5Y cells and microglia-conditioned medium (MCM) stimulated by lipopolysaccharide (LPS) and interferon-gamma (IFNγ). MMP9 and TIMP1 levels were measured with ELISA assay to confirm the UA effect. We added recombinant MMP9 (rMMP9) and TIMP1 neutralizing antibody (anti-TIMP1) for reconfirmation. Transmission electron microscopy was used to observe cell morphology, and flow cytometry and Annexin V-FITC and PI labeling for apoptotic conditions. We further measured the calcium fluorescence intensity in SH-SY5Y cells. Results: The MCM significantly reduced cell viability of SH-SY5Y cells after OGDR (p<0.01), which was restored by UA (0.25 µM) (p<0.05), whereas lactate dehydrogenase activity, intraneuronal Ca2+ concentration, and apoptosis-related indexes were showed significant improvement after UA treatment (p<0.01). UA corrected the MMP/TIMP imbalance by decreasing MMP9 expression and increasing TIMP1 expression in the co-culture system (p<0.01) and the effects of UA on SH-SY5Y cells were mitigated by the administration of rMMP9 and anti-TIMP1 (p<0.01). Conclusion: We demonstrated that UA inhibited microglia-induced neuronal cell death in an OGDR model of ischemic reperfusion injury by stabilizing the MMP9/TIMP1 imbalance.

Association between HMGB1 genetic variants and ischemic stroke susceptibility, onset age, and recurrence risk among Chinese Han individuals.

OBJECTIVES: Ischemic stroke has long been a global health threat. Genetic factors, a looming risk for ischemic stroke, remain unexplored. The high-mobility group box 1 (HMGB1) protein showed a connection with the occurrence and development of ischemic stroke. This study was conducted to find whether frequent HMGB1 polymorphisms (rs1045411, rs1412125, and rs2249825) play a role in ischemic stroke susceptibility and recurrence risk. METHODS: Our study was carried out in a Chinese Han population with a sample size of 871 patients and 858 age-matched healthy controls. Tag single nucleotide polymorphisms (tagSNPs) were selected by conventional protocols and DNA was extracted for genotype analysis after the participants had signed an informed consent. Comprehensive statistical analyses were conducted. RESULTS: It was found that the C allele of the HMGB1 rs1412125 (OR = 1.263, 95% CI = 1.075-1.483, P = 0.004) and HMGB1 rs2249825 (adjusted OR = 2.464, 95% CI = 1.215-4.996, P = 0.012) variants was associated with a high risk of ischemic stroke, with the male subgroup carrying the TT allele of the HMGB1 rs1045411 variant tended to suffer more from the disease (adjusted OR = 3.600, 95% CI = 1.272-10.193, P = 0.016). A haplotype study also showed significant results (OR = 1.554, 95% CI = 1.246-1.938, P = 0.001). The rs1412125 polymorphism was highly associated with the chance of recurrence but not with the onset age (TC vs. TT: P = 0.034; CC vs. TT: P < 0.001). Cox regression analysis and stratified analysis were carried out with notable conclusions. CONCLUSIONS: Our study provided evidence for the association between HMGB1 polymorphisms and ischemic stroke susceptibility and recurrence, indicating that HMGB1 gene variants may be potential markers for first and secondary stroke prevention.

Genetic polymorphisms of pri-let-7f, gene-environment and gene-gene interactions, and associations with ischemic stroke risk in Liaoning Province.

OBJECTIVE: The incidence of stroke has been rising annually and investigations into traditional risk factors have led to increased attention on genetic factors. In this study, we focused on the pri-let-7f gene, and investigated the association between pri-let-7f gene polymorphisms and ischemic stroke (IS). METHODS: This case-control study included 1803 patients and 1456 healthy controls of Han ethnicity living in Liaoning Province. We carried out genotyping analysis of two loci, pri-let-7f-1 rs10739971 and pri-let-7f-2 rs17276588, and performed statistical analysis controlling for confounding factors by logistic regression. RESULTS: The A alleles and AA genotypes of both loci were significantly associated with an increased risk of IS. Variant genotypes of rs17276588 may also increase the risk of IS in females with alcohol intake. Gene-gene interaction analysis showed combined effects of mutations in both these single nucleotide polymorphisms (SNPs). CONCLUSIONS: This study demonstrated an association between pri-let-7f SNPs and IS, providing potential latent biomarkers for the risk of IS. However, more detailed studies are needed to clarify these results.

Ursolic acid promotes microglial polarization toward the M2 phenotype via PPARγ regulation of MMP2 transcription.

Microglia, which are the primary inflammatory cells of the brain, can undergo phenotypic switching between M1 and M2 polarization, which have opposing effects on inflammation. Peroxisome proliferator-activated receptor gamma (PPARγ) is a member of the nuclear receptor family of ligand-inducible transcription factors, and PPARγ is known to regulate M2 macrophage polarization. Previous studies have shown that the natural pentacyclic triterpenoid ursolic acid (3ß-hydroxy-urs-12-en-28-oic acid; UA) influences microglial activation. Additionally, UA increases tissue inhibitor matrix metalloproteinase 1 (TIMP1), while greatly reducing the release of matrix metalloproteinase 2 (MMP2) and MMP9 in a PPARγ-dependent manner. Here, we examined the anti-inflammatory properties of UA by observing how well it promotes the phenotypic transition of lipopolysaccharide (LPS) and interferon gamma (IFNγ)-activated BV2 microglia from M1 to M2 polarization. To determine if PPARγ is involved in the underlying molecular pathway, we treated rats with UA and the PPARγ inhibitor BADGE. We also investigated the mechanisms by which PPARγ controls transcription from the MMP2 promoter. The in-vitro experiments showed that UA shifted LPS/IFNγ-activated BV2 microglia from the M1 to the M2 phenotype, which was associated with a reduction in the neurotoxic factors MMP2 and MMP9, and an increase in the anti-inflammatory factor TIMP1. Co-treatment with increased MMP2 and MMP9 synthesis while decreasing TIMP1 release, indicating that UA has anti-inflammatory effects on LPS/IFNγ-activated BV2 cells via activation of PPARγ. Next, we found that PPARγ directly influences MMP2 transcriptional activity by identifying the crucial peroxisome proliferator response element (PPRE) among five potential PPREs in the MMP2 promoter. These results suggest that UA has a protective anti-inflammatory effect against neuroinflammatory toxicity, which is exerted by direct activation of PPARγ and selectively modulates microglial polarization and suppresses MMP2 formation.

Genetic variants in the promoters of let-7 are associated with the risk and age at onset of ischemic stroke: A case control study.

PURPOSE: Let-7 family members serve as crucial regulatory molecules in the pathogenesis of ischemic stroke. We predicted that genetic variations in the let-7 family's promoters may be linked to the risk of ischemic stroke. The connection of rs10877887 and rs13293512 in the let-7 family promoters with liability to ischemic stroke was explored in this study. PATIENTS AND METHODS: Clinical data and peripheral blood samples were collected from 914 ischemic stroke patients and 836 controls in this case-control study. All statistical analyses were carried out using SPSS. RESULTS: Our analysis results reveal that the rs10877887 TC+CC genotype in the dominant model is associated with a lower risk of ischemic stroke than the TT genotype. Individuals with heterozygous TC or homozygous CC genotypes in the male population showed higher odds of ischemic stroke than those with the wild TT genotype in rs13293512 analysis. Furthermore, there existed a multiplicative interaction between the rs10877887 C allele and the rs13293512 T allele. In the presence of the rs13293512 T allele, the effect of the rs10877887 C allele on ischemic stroke risk was increased. Similarly, in the presence of the rs10877887 C allele, the outcome of the rs13293512 T allele on ischemic stroke risk was elevated. In addition, the rs13293512 CC genotype seemed to lead to an earlier onset of ischemic stroke. CONCLUSION: Our findings indicated that these two SNPs might have a joint role in IS and could potentially act as risk markers. Detecting let-7 promoter polymorphisms could raise awareness of the risk of IS, which directed individuals with risk alleles to have regular checks at an appropriate frequency to avoid developing the disease.

Genetic variation within the pri-let-7f-2 in the X chromosome predicting stroke risk in a Chinese Han population from Liaoning, China: From a case-control study to a new predictive nomogram.

Background and objectives: Stroke is the most common cause of disability and the second cause of death worldwide. Therefore, there is a need to identify patients at risk of developing stroke. This case-control study aimed to create and verify a gender-specific genetic signature-based nomogram to facilitate the prediction of ischemic stroke (IS) risk using only easily available clinical variables. Materials and methods: A total of 1,803 IS patients and 1,456 healthy controls from the Liaoning province in China (Han population) were included which randomly divided into training cohort (70%) and validation cohort (30%) using the sample function in R software. The distribution of the pri-let-7f-2 rs17276588 variant genotype was analyzed. Following genotyping analysis, statistical analysis was used to identify relevant features. The features identified from the multivariate logistic regression, the least absolute shrinkage and selection operator (LASSO) regression, and univariate regression were used to create a multivariate prediction nomogram model. A calibration curve was used to determine the discrimination accuracy of the model in the training and validation cohorts. External validity was also performed. Results: The genotyping analysis identified the A allele as a potential risk factor for IS in both men and women. The nomogram identified the rs17276588 variant genotype and several clinical parameters, including age, diabetes mellitus, body mass index (BMI), hypertension, history of alcohol use, history of smoking, and hyperlipidemia as risk factors for developing IS. The calibration curves for the male and female models showed good consistency and applicability. Conclusion: The pri-let-7f-2 rs17276588 variant genotype is highly linked to the incidence of IS in the northern Chinese Han population. The nomogram we devised, which combines genetic fingerprints and clinical data, has a lot of promise for predicting the risk of IS within the Chinese Han population.