FABP3 Induces Mitochondrial Autophagy to Promote Neuronal Cell Apoptosis in Brain Ischemia-Reperfusion Injury.

This study elucidates the molecular mechanisms by which FABP3 regulates neuronal apoptosis via mitochondrial autophagy in the context of cerebral ischemia-reperfusion (I/R). Employing a transient mouse model of middle cerebral artery occlusion (MCAO) established using the filament method, brain tissue samples were procured from I/R mice. High-throughput transcriptome sequencing on the Illumina CN500 platform was performed to identify differentially expressed mRNAs. Critical genes were selected by intersecting I/R-related genes from the GeneCards database with the differentially expressed mRNAs. The in vivo mechanism was explored by infecting I/R mice with lentivirus. Brain tissue injury, infarct volume ratio in the ischemic penumbra, neurologic deficits, behavioral abilities, neuronal apoptosis, apoptotic factors, inflammatory factors, and lipid peroxidation markers were assessed using H&E staining, TTC staining, Longa scoring, rotation experiments, immunofluorescence staining, and Western blot. For in vitro validation, an OGD/R model was established using primary neuron cells. Cell viability, apoptosis rate, mitochondrial oxidative stress, morphology, autophagosome formation, membrane potential, LC3 protein levels, and colocalization of autophagosomes and mitochondria were evaluated using MTT assay, LDH release assay, flow cytometry, ROS/MDA/GSH-Px measurement, transmission electron microscopy, MitoTracker staining, JC-1 method, Western blot, and immunofluorescence staining. FABP3 was identified as a critical gene in I/R through integrated transcriptome sequencing and bioinformatics analysis. In vivo experiments revealed that FABP3 silencing mitigated brain tissue damage, reduced infarct volume ratio, improved neurologic deficits, restored behavioral abilities, and attenuated neuronal apoptosis, inflammation, and mitochondrial oxidative stress in I/R mice. In vitro experiments demonstrated that FABP3 silencing restored OGD/R cell viability, reduced neuronal apoptosis, and decreased mitochondrial oxidative stress. Moreover, FABP3 induced mitochondrial autophagy through ROS, which was inhibited by the free radical scavenger NAC. Blocking mitochondrial autophagy with sh-ATG5 lentivirus confirmed that FABP3 induces mitochondrial dysfunction and neuronal apoptosis by activating mitochondrial autophagy. In conclusion, FABP3 activates mitochondrial autophagy through ROS, leading to mitochondrial dysfunction and neuronal apoptosis, thereby promoting cerebral ischemia-reperfusion injury.

[Impact of atrial fibrillation on clinical outcome in patients with acute ischemic stroke undergoing thrombolytic therapy].

OBJECTIVE: To investigate the impact of atrial fibrillation (AF) on clinical outcomes in patients with acute ischemic stroke undergoing thrombolytic therapy. METHODS: The clinical data of 330 patients with acute ischemic stroke who received intravenous recombinant tissue plasminogen activator (rt-PA) therapy in the Second Affiliated Hospital, Zhejiang University School of Medicine between June 2009 and August 2013 were reviewed. Clinical outcomes in AF and non-AF groups were evaluated by univariate and multivariate analysis. Favorable outcome was defined as a modified Rankin Scale (mRS) 0-2 on day 90. Hemorrhagic transformation (HT) was classified as hemorrhagic infarction (HI) and parenchymal hematoma (PH) within the first 24h according to ECASS II criteria. Hypoperfusion and severe hypoperfusion were defined as Tmax >6 s and >8 s, respectively. The rate of reperfusion was compared between AF and non-AF groups. RESULTS: Among 330 patients, 137(41.5%) had AF. Compared with non-AF patients, patients with AF were older [(71.7±11.5)y vs (63.4±13.2)y, P<0.001], had higher baseline National Institutes of Health Stroke Scale [IQR, 13(8-16) vs 9(5-15), P<0.001], higher rate of HT(HI: 28.5% vs 17.1%, P=0.015; PH: 13.9% vs 4.1%, P=0.002), and lower rate of favorable outcome (41.5% vs 58.0%, P=0.005) at d 90. After adjustment, AF was not a risk factor for favorable outcome (OR=0.920, 95%CI:0.533-1.586; P=0.763) and mortality (OR=1.381, 95%CI:1.096-1.242; P=0.466) on day 90. AF was also not associated with HI (OR=1.676, 95%CI: 0.972-3.031; P=0.088), but it increased the rate of PH (OR=3.621, 95%CI: 1.403-9.344; P=0.008). Among 94 patients with pre- and post-thrombolytic perfusion-weighted image, AF was not associated with increased rate of reperfusion for hypoperfusion (Tmax >6 s, OR=1.12, 95%CI: 0.35-3.63, P=0.849), but was correlated with increased rate of reperfusion for severe hypoperfusion (Tmax>8 s, OR=10.57, 95%CI:1.16-96.50, P=0.037). CONCLUSION: The presence of AF has no independent impact on neurological outcome in thrombolytic patients with acute ischemic stroke. It is associated with increased reperfusion rate of more severe hypoperfusion area and higher frequency of PH.

[Risk factors of hemorrhagic transformation in different locations and its relation to clinical outcomes of patients with acute ischemic stroke following intravenous thrombolysis].

OBJECTIVE: To investigate the risk factors of hemorrhagic transformation (HT) in different cerebral regions and to explore its relation to clinical outcomes of patients with acute ischemic stroke after intravenous thrombolysis therapy. METHODS: The clinical, laboratory, and radiological data of 292 consecutive acute ischemic stroke patients undergoing intravenous thrombolysis therapy in Second Affiliated Hospital, Zhejiang University School of Medicine from June 2009 to May 2013 was retrospectively analyzed. Deep HT was defined as HT located in basal ganglia, internal capsule, external capsule and thalamus, otherwise the lesion was defined as non-deep HT. Patients were divided into 3 groups [Deep HT(n=47), non-deep HT(n=82), non HT(n=8)] and the differences in clinical and demographic characteristics were compared by using one-way analysis of variance and Ξ2-test. Multivariable logistic regression models were used to determine the independent risk factors of HT in different cerebral regions and clinical outcomes. RESULTS: Age, baseline National Institutes of Health Stroke Scale (NIHSS) score, baseline systolic blood pressure and the frequency of atrial fibrillation were different among three groups. Logistic regression analysis revealed that baseline NIHSS score (OR=1.126, 95%CI:1.063-1.193, P<0.001) and baseline systolic blood pressure (OR=0.982, 95%CI:0.967-0.998, P=0.020) were independent risk factors of deep HT. Multivariate analysis also found that deep HT was an independent predictor of functional outcome after thrombolysis (OR=0.291, 95%CI:0.133-0.640, P=0.002). CONCLUSION: Baseline NIHSS score and systolic blood pressure are predictors for deep hemorrhagic transformation, which indicates the poor functional outcome of patients with acute ischemic stroke following thrombolytic therapy.