Impact of triglyceride playing on stroke severity correlated to bilirubin

Association of MMP3, MMP14, and MMP25 gene polymorphisms with cerebral stroke risk: a case-control study

BACKGROUND

Cerebral stroke (CS) is the leading cause of death in China, and a complex disease caused by both alterable risk factors and genetic factors. This study intended to investigate the association of MMP3, MMP14, and MMP25 single nucleotide polymorphisms (SNPs) with CS risk in a Chinese Han population.

METHODS

A total of 1,348 Han Chinese were recruited in this case-control study. Four candidate loci including rs520540 A/G and rs679620 T/C of MMP3, rs2236302 G/C of MMP14, and rs10431961 T/C of MMP25 were successfully screened. The correlation between the four SNPs and CS risk was assessed by logistic regression analysis. The results were analyzed by false-positive report probability (FPRP) for chance or significance. The interactions between four SNPs associated with CS risk were assessed by multifactor dimensionality reduction (MDR).

RESULTS

rs520540 A/G and rs679620 C/T SNP in MMP3 were associated with risk of CS in allele, codominant, dominant and log-additive models. Ischemic stroke risk were significantly lower in carriers with rs520540-A allele and rs679620-T allele than those with G/G or C/C genotypes. However, rs520540-A allele and rs679620-T allele were associated with higher risk of hemorrhagic stroke. Stratified analysis showed that these two SNPs were associated with reduced risk of CS in aged < 55 years, non-smoking and non-drinking participants, and rs679620 SNP also reduced CS risk in male participants. The levels of uric acid, high-density lipoprotein cholesterol, and eosinophil were different among patients with different genotypes of rs520540 and rs679620. No statistically significant association was found between MMP14 rs2236302 G/C or MMP25 rs10431961 T/C with CS even after stratification by stroke subtypes, age, gender as well as smoking and drinking conditions in all the genetic models.

CONCLUSION

MMP3 rs520540 A/G and rs679620 C/T polymorphisms were associated with CS risk in the Chinese Han population, which provides useful information for the prevention and diagnosis of CS.

Lipidomic analysis identifies long-chain acylcarnitine as a target for ischemic stroke

INTRODUCTION

Lipid metabolism dysfunction is widely involved in the pathological process of acute ischemic stroke (AIS). The coordination of lipid metabolism between neurons and astrocytes is of great significance. However, the full scope of lipid dynamic changes and the function of key lipids during AIS remain unknown. Hence, identifying lipid alterations and characterizing their key roles in AIS is of great importance.

METHODS

Untargeted and targeted lipidomic analyses were applied to profile lipid changes in the ischemic penumbra and peripheral blood of transient middle cerebral artery occlusion (tMCAO) mice as well as the peripheral blood of AIS patients. Infarct volume and neurological deficits were assessed after tMCAO. The cell viability and dendritic complexity of primary neurons were evaluated by CCK8 assay and Sholl analysis. Seahorse, MitoTracker Green, tetramethyl rhodamine methyl ester (TMRM), 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSOX were used as markers of mitochondrial health. Fluorescent and isotopic free fatty acid (FFA) pulse-chase assays were used to track FFA flux in astrocytes.

RESULTS

Long-chain acylcarnitines (LCACs) were the lipids with the most dramatic changes in the ischemic penumbra and peripheral blood of tMCAO mice. LCACs were significantly elevated on admission in AIS patients and associated with poor outcomes in AIS patients. Increasing LCACs through a bolus administration of palmitoylcarnitine amplified stroke injury, while decreasing LCACs by overexpressing carnitine palmitoyltransferase 2 (CPT2) ameliorated stroke injury. Palmitoylcarnitine aggravated astrocytic mitochondrial damage after OGD/R, while CPT2 overexpression in astrocytes ameliorated cocultured neuron viability. Further study revealed that astrocytes stimulated by OGD/R liberated FFAs from lipid droplets into mitochondria to form LCACs, resulting in mitochondrial damage and lowered astrocytic metabolic support and thereby aggravated neuronal damage.

CONCLUSION

LCACs could accumulate and damage neurons by inducing astrocytic mitochondrial dysfunction in AIS. LCACs play a crucial role in the pathology of AIS and are novel promising diagnostic and prognostic biomarkers for AIS.

Association between bilirubin levels with incidence and prognosis of stroke: A meta-analysis

Objective

Bilirubin has anti-inflammatory, antioxidant, and neuroprotective properties, but the association between bilirubin and stroke remains contentious. A meta-analysis of extensive observational studies on the relationship was conducted.

Methods

Studies published before August 2022 were searched in PubMed, EMBASE, and Cochrane Library. Cohort, cross-sectional and case-control studies that examined the association between circulating bilirubin and stroke were included. The primary outcome included the incidence of stroke and bilirubin quantitative expression level between stroke and control, and the secondary outcome was stroke severity. All pooled outcome measures were determined using random-effects models. The meta-analysis, subgroup analysis, and sensitivity analysis were performed using Stata 17.

Results

A total of 17 studies were included. Patients with stroke had a lower total bilirubin level (mean difference = -1.33 μmol/L, 95% CI: -2.12 to -0.53, P < 0.001). Compared with the lowest bilirubin level, total odds ratio (OR) of the highest bilirubin for the occurrence of stroke was 0.71 (95% CI: 0.61-0.82) and ischemic stroke was 0.72 (95% CI: 0.57-0.91), especially in cohort studies with accepted heterogeneity (I 2 = 0). Serum total and direct bilirubin levels were significantly and positively associated with stroke severity. A stratified analysis based on gender showed that the total bilirubin level in males correlated with ischemic stroke or stroke, which was not noted in females.

Conclusion

While our findings suggest associations between bilirubin levels and stroke risk, existing evidence is insufficient to establish a definitive association. Better-designed prospective cohort studies should further clarify pertinent questions (PROSPERO registration number: CRD42022374893).

Network pharmacology and molecular docking-based analysis of protective mechanism of MLIF in ischemic stroke

Objective

This study aimed to evaluate the potential mechanism by which Monocyte locomotion inhibitory factor (MLIF) improves the outcome of ischemic stroke (IS) inflammatory injury.

Methods

Potential MLIF-related targets were predicted using Swiss TargetPrediction and PharmMapper, while IS-related targets were found from GeneCards, PharmGKB, and Therapeutic Target Database (TTD). After obtaining the intersection from these two datasets, the Search Tool for Retrieval of Interacting Genes/Protein (STRING11.0) database was used to analyze the protein-protein interaction (PPI) network of the intersection and candidate genes for MLIF treatment of IS. The candidate genes were imported into the Metascape database for Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. The top 20 core genes and the “MLIF-target-pathway” network were mapped using the Cytoscape3.9.1. Using AutoDock Vina1.1.2, the molecular docking validation of the hub targets and MLIF was carried out. In the experimental part, transient middle cerebral artery occlusion (tMCAO) and oxygen and glucose deprivation (OGD) models were used to evaluate the protective efficacy of MLIF and the expression of inflammatory cytokines and the putative targets.

Results

MLIF was expected to have an effect on 370 targets. When these targets were intersected with 1,289 targets for ischemic stroke, 119 candidate therapeutic targets were found. The key enriched pathways were PI3K-Akt signaling pathway and MAPK signaling pathway, etc. The GO analysis yielded 1,677 GO entries (P &lt; 0.01), such as hormone stimulation, inflammatory response, etc. The top 20 core genes included AKT1, EGFR, IGF1, MAPK1, MAPK10, MAPK14, etc. The result of molecular docking demonstrated that MLIF had the strong binding capability to JNK (MAPK10). The in vitro and in vivo studies also confirmed that MLIF protected against IS by lowering JNK (MAPK10) and AP-1 levels and decreasing pro-inflammatory cytokines (IL-1, IL-6).

Conclusion

MLIF may exert a cerebral protective effect by inhibiting the inflammatory response through suppressing the JNK/AP-1 signaling pathway.

Is Bilirubin Associated with the Severity of Ischemic Stroke? A Dose Response Meta-Analysis

There is no consensus on the role of bilirubin in acute ischemic stroke. Higher levels of serum bilirubin may provide a treatment advantage in oxidative-stress-mediated diseases but also may simply reflect the strength of the oxidative stress. As of 28 February 2022, the relevant studies were selected from four databases (PubMed, Web of science, Cochrane, and CNKI) through a retrieval strategy, and strict literature screening and quality evaluation were carried out. The dose–response relationship was fitted with a restricted cubic splines function. We found that the serum total bilirubin level and the direct bilirubin level were positively correlated with the severity of ischemic stroke. The direct bilirubin level was linearly correlated with the severity of stroke (P for non-linearity = 0.55), and the direct bilirubin increase of 1 μmol/L may be related to the 1% increase in the possibility of having moderate or severe ischemic stroke. High bilirubin levels are associated with stroke severity in patients with ischemic stroke and may serve as a marker of the intensity of initial oxidative stress.

The association between serine hydroxymethyl transferase 1 gene hypermethylation and ischemic stroke

This study aimed to determine the correlation between serine hydroxymethyl transferase 1 (SHMT1) gene methylation and ischemic stroke. A total of 202 age- and sex-matched individuals were included. Quantitative methylation-specific polymerase chain reaction (qMSP-PCR) was used to analyze the DNA methylation level. The plasma homocysteine (Hcy) concentration was much higher in ischemic cases than in controls (p = 0.009), while the high-density lipoprotein (HDL) levels in stroke cases were considerably lower than in controls (p = 0.005). A significantly higher level of SHMT1 methylation was observed in the ischemic strokes (58.82 ± 17.83%) compared to that in the controls (42.59 ± 20.76%, p < 0.001). The SHMT1 methylation level was strongly correlated with HDL concentration in the healthy controls (r = 0.517, p < 0.001), while the high plasma level of Hcy showed strong association with SHMT1 methylation in ischemic strokes (r = 0.346, p < 0.001). Receiver operating characteristic (ROC) analysis of curve indicated that SHMT1 methylation has been an acceptable indicator for ischemic stroke in female patients [all sexes, area under the curve (AUC) = 0.71, p < 0.001; male patients AUC = 0.62, p = 0.032; and female patients AUC = 0.79, p < 0.001] and in all ages (AUC = 0.71, p < 0.001). In our samples, DNA methylation levels of the STHMI gene were significantly correlated with ischemic stroke in Han Chinese. STHMI hypermethylation was significantly associated with the high Hcy concentration in ischemic stroke and had value as a potential indicator for female ischemic stroke.