Exploration of Risk Factors for Poor Prognosis of Non-Traumatic Non-Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating neurological disease associated with high rates of mortality and disability. Aneurysms are the main cause of non-traumatic subarachnoid hemorrhages. However, non-traumatic non-aneurysmal subarachnoid hemorrhage (naSAH), another clinical type of SAH, has been poorly studied for its prognosis and risk factors. METHOD AND RESULT: We collected demographic and clinical variables for 126 naSAH and 89 aneurysmal subarachnoid hemorrhage (aSAH) patients, including age and gender; hospitalization days; hematological indicators; clinical score scales; past medical history; and personal history. We found that the monocytes in naSAH (0.50 ± 0.26) patients were lower than in aSAH patients (0.60 ± 0.27). The prevalence of diabetes in naSAH (30.2%) patients was higher than in aSAH (14.5%) patients. The naSAH patients were divided into good and poor outcome groups based on the modified Rankin Scale at the 90th day (90-day mRS) after discharge. A univariate analysis showed that there were significant differences in age, white blood cell count (WBC), monocyte count, D-dipolymer, neuron-specific enolase (NSE), random blood glucose (RBG), aspartate transaminase (AST), urea and free triiodothyronine (FT3) between the two groups. A logistic regression showed that aging and high level NSE were independent risk factors for a poor outcome. The predictive ability of age (area under curve (AUC) = 0.71) and NSE (AUC = 0.68) were analyzed by a receiver operating characteristic (ROC) curve. The results of the logistic regression suggested that age, D-dipolymer, NSE, RBG, urea and FT3 distinguished and predicted the prognosis of naSAH. The discriminant analysis of the above variables revealed that the discriminant accuracy was 80.20%. CONCLUSIONS: Compared with aSAHs, naSAHs are more likely to occur in patients with diabetes, and the level of monocytes is lower. Moreover, the prognosis of elderly patients with an naSAH is relatively poor, and the level of NSE in the course of the disease also reflects the prognosis. Multivariate comprehensive analysis is helpful to judge the prognosis of patients at a small cost.

Activation of ERK-Drp1 signaling promotes hypoxia-induced Aß accumulation by upregulating mitochondrial fission and BACE1 activity.

Hypoxia is a risk factor for Alzheimer's disease (AD). Besides, mitochondrial fission is increased in response to hypoxia. In this study, we sought to investigate whether hypoxia-induced mitochondrial fission plays a critical role in regulating amyloid-ß (Aß) production. Hypoxia significantly activated extracellular signal-regulated kinase (ERK), increased phosphorylation of dynamin-related protein 1 (Drp1) at serine 616, and decreased phosphorylation of Drp1 at serine 637. Importantly, hypoxia triggered mitochondrial dysfunction, elevated ß-secretase 1 (BACE1) and γ-secretase activities, and promoted Aß accumulation in HEK293 cells transfected with ß-amyloid precursor protein (APP) plasmid harboring the Swedish and Indiana familial Alzheimer's disease mutations (APPSwe/Ind HEK293 cells). Then, we investigated whether the ERK inhibitor PD325901 and Drp1 inhibitor mitochondrial division inhibitor-1 (Mdivi-1) would attenuate hypoxia-induced mitochondrial fission and Aß generation in APPSwe/Ind HEK293 cells. PD325901 and Mdivi-1 inhibited phosphorylation of Drp1 at serine 616, resulting in reduced mitochondrial fission under hypoxia. Furthermore, hypoxia-induced mitochondrial dysfunction, BACE1 activation, and Aß accumulation were downregulated by PD325901 and Mdivi-1. Our data demonstrate that hypoxia induces mitochondrial fission, impairs mitochondrial function, and facilitates Aß generation. The ERK-Drp1 signaling pathway is partly involved in the hypoxia-induced Aß generation by regulating mitochondrial fission and BACE1 activity. Therefore, inhibition of hypoxia-induced mitochondrial fission may prevent or slow the progression of AD.

Kaempferol Ameliorates Oxygen-Glucose Deprivation/Reoxygenation-Induced Neuronal Ferroptosis by Activating Nrf2/SLC7A11/GPX4 Axis.

Kaempferol has been shown to protect cells against cerebral ischemia/reperfusion injury through inhibition of apoptosis. In the present study, we sought to investigate whether ferroptosis is involved in the oxygen-glucose deprivation/reperfusion (OGD/R)-induced neuronal injury and the effects of kaempferol on ferroptosis in OGD/R-treated neurons. Western blot, immunofluorescence, and transmission electron microscopy were used to analyze ferroptosis, whereas cell death was detected using lactate dehydrogenase (LDH) release. We found that OGD/R attenuated SLC7A11 and glutathione peroxidase 4 (GPX4) levels as well as decreased endogenous antioxidants including nicotinamide adenine dinucleotide phosphate (NADPH), glutathione (GSH), and superoxide dismutase (SOD) in neurons. Notably, OGD/R enhanced the accumulation of lipid peroxidation, leading to the induction of ferroptosis in neurons. However, kaempferol activated nuclear factor-E2-related factor 2 (Nrf2)/SLC7A11/GPX4 signaling, augmented antioxidant capacity, and suppressed the accumulation of lipid peroxidation in OGD/R-treated neurons. Furthermore, kaempferol significantly reversed OGD/R-induced ferroptosis. Nevertheless, inhibition of Nrf2 by ML385 blocked the protective effects of kaempferol on antioxidant capacity, lipid peroxidation, and ferroptosis in OGD/R-treated neurons. These results suggest that ferroptosis may be a significant cause of cell death associated with OGD/R. Kaempferol provides protection from OGD/R-induced ferroptosis partly by activating Nrf2/SLC7A11/GPX4 signaling pathway.

Parkin overexpression attenuates Aß-induced mitochondrial dysfunction in HEK293 cells by restoring impaired mitophagy.

AIMS: Mitochondrial dysfunction is an early prominent feature of Alzheimer's disease (AD). In the present study, we sought to investigate whether defective mitophagy is tightly related to amyloid-ß (Aß)-induced mitochondrial dysfunction. MAIN METHODS: Immunofluorescence, western blot and transmission electron microscopy were used to examine mitophagy. Mitochondrial membrane potential was assessed using the JC-1 dye. Mitochondrial ROS was detected using MitoSOX™ Red staining. KEY FINDINGS: Aß induced mitochondrial dysfunction in HEK293 cells. Moreover, Aß induced an increase in parkin translocation to mitochondria and led to a drastic reduction in cytosolic parkin. Furthermore, Aß-treated cells displayed a microtubule-associated protein 1 light chain 3 (LC3) punctate pattern and elevated mitochondrial LC3-II levels, suggesting the upregulation of mitophagy. Notably, Aß induced the accumulation of mitochondrial p62, which was associated with impaired mitophagy. In addition, Aß-treated cells exhibited fragmented or swollen mitochondria with severely decreased cristae. We then investigated whether overexpression of parkin could protect cells against Aß-induced mitochondrial dysfunction. Interestingly, parkin overexpression inhibited Aß-induced mitochondrial dysfunction. Besides, parkin overexpression increased cytosolic and mitochondrial parkin levels as well as mitochondrial LC3-II levels in Aß-treated cells. Additionally, parkin overexpression reversed the accumulation of p62 in mitochondria, indicating that parkin overexpression restored impaired mitophagy in Aß-treated cells. Importantly, parkin overexpression remarkably reversed Aß-induced mitochondrial fragmentation. SIGNIFICANCE: Our data demonstrate that overexpression of parkin ameliorates impaired mitophagy and promotes the removal of damaged mitochondria in Aß-treated cells, indicating that upregulation of parkin-mediated mitophagy may be a potential strategy for the therapy of AD.

Role of Macrophages in Status Epilepticus Predisposing to Alzheimer's Disease.

Continuous epileptic seizures hallmark status epilepticus, leading to preferential neuronal cell loss in the hippocampus that can progress into Alzheimer's disease. Previous studies have shown that status epilepticus prompts an overproduction of nitric oxide (NO) by upregulation of NO synthase II (NOS II) to induce apoptosis of neuronal cells in the hippocampus, in a nuclear factor-kappaB (NF-κB) signaling dependent manner. Here, in an experimental rat model for status epilepticus, elicitation of sustained seizure activity was achieved by microinjection of kainic acid (KA) into the hippocampal CA3 subfield. We found that KA induced features of status epilepticus, which could be attenuated by blocking NF-κB signaling through a specific inhibitor. Interestingly, infiltration of macrophages of primarily pro-inflammatory subtype was detected in the hippocampal CA3 region immediately after KA injection. Experimental elimination of macrophages by an anti-CD115 antibody significantly attenuated the features of status epilepticus, likely through suppressing activation of NF-κB signaling. Together, these data suggest that macrophages play a critical role in NF-κB signaling-mediated status epilepticus that predisposes to Alzheimer's disease.

The value of multidisciplinary team in syncope clinic for the effective diagnosis of complex syncope.

BACKGROUND: Syncope is a perplexing challenge that often receives thorough evaluation, yet the diagnosis remains unclear. Usually, the emergency department is the first point at which patients present with syncope. However, diverse medical factors, including low diagnostic rates and inconsistent management by doctors, add to healthcare costs and delay diagnosis for syncope patients. METHODS: Patients who had been to the emergency department at least once but were not given a clear diagnosis of syncope were recruited into our study at the time they visited syncope clinic staffed by a multidisciplinary team. Complete medical histories and clinical examinations were conducted by both experienced cardiologists and neurologists. If patients were not given a conclusive diagnosis at the syncope clinic on the basis of outpatient examinations, they were admitted for further evaluation. RESULTS: A total of 209 consecutive patients claiming "syncope" visited the syncope clinic, yet only 167 patients were formally diagnosed with syncope. For these 167 patients, the mean age was 55.93 ± 17.40 years old, and 41.3% were male. The proportions of cardiac syncope, reflex syncope, orthostatic hypotension (OH), and syncope of uncertain etiology were 19.8%, 64.1%, 7.8%, and 8.4%, respectively. The diagnostic rate was 91.6%, and the hospitalization rate was 23.4%. Patients with reflex syncope and OH were younger than patients with cardiac syncope. Cardiac syncope tends to occur more frequently in males, while reflex syncope is more likely in females. CONCLUSIONS: The cooperation of professional cardiologists and neurologists will play an important role in improving diagnostic rates, lowering admission rates, and reducing medical costs.

Edaravone Attenuates the Proinflammatory Response in Amyloid-ß-Treated Microglia by Inhibiting NLRP3 Inflammasome-Mediated IL-1ß Secretion.

BACKGROUND/AIMS: Microglial activation is an important pathological feature in the brains of patients with Alzheimer's disease (AD), and amyloid-ß (Aß) peptides play a crucial role in microglial activation. In addition, edaravone (EDA) was recently shown to suppress oxidative stress and proinflammatory cytokine production in APPswePS1dE9 (APP/PS1) mice. However, the mechanism by which EDA inhibits the Aß-induced proinflammatory response in microglia is poorly understood. METHODS: The mitochondrial membrane potential (∆ψm) was evaluated using JC-1 staining. Intracellular reactive oxygen species (ROS) and mitochondrial ROS levels were detected using CM-H2DCFDA and MitoSOXTM Red, respectively. The levels of CD11b, NLRP3, pro-caspase-1 and manganese superoxide dismutase (SOD-2) were observed by western blotting, and the levels of interleukin-1beta (IL-1ß) in culture supernatants were quantified using an ELISA kit. RESULTS: Aß induced microglia activation and mitochondrial dysfunction. In addition, mitochondrial dysfunction was associated with ROS accumulation and activation of the NLRP3 inflammasome. Importantly, Aß induced activation of the NLRP3 inflammasome, leading to caspase-1 activation and IL-1ß release in microglia. Moreover, EDA obviously attenuated the depolarization of ∆ψm, reduced mitochondria-derived ROS production and increased SOD-2 activity, resulting in the suppression of NLRP3 inflammasome-mediated IL-1ß secretion in Aß-treated microglia. CONCLUSION: EDA is a mitochondria-targeted antioxidant and exhibits anti-inflammatory effects on Aß-treated microglia.

Changes in serum vascular endothelial growth factor and endostatin concentrations associated with circulating endothelial progenitor cells after acute ischemic stroke.

Angiogenesis is an important pathophysiological response to cerebral ischemia, and can be modulated by vascular endothelial growth factor (VEGF) and endostatin. Circulating endothelial progenitor cells (EPCs) also play an important role as an endogenous repair mechanism for ischemic injury. We sought to investigate early changes in the expression of VEGF and endostatin in serum and the circulating EPCs in patients with acute ischemic stroke (AIS) and analyzed the relations between them. The peripheral blood and serum samples were obtained from 30 patients at 1, 3, 5 and 7 d after AIS. Flow cytometry was used to quantify EPCs, and VEGF and endostatin were measured by enzyme linked immunosorbent assay. Correlation analysis was performed to assess the relations between them. Receiver operating characteristic (ROC) curve was used to appraise the value of EPCs levels in predicting the 90-day prognosis after AIS. Compared with control subjects, circulating EPCs numbers increased from a very lower initial level (P < 0.001) until 7 d after AIS. Serum VEGF and endostatin levels increased and peaked at 3 d and 5 d post-stroke (both P < 0.001), respectively. A significant correlation (P = 0.001) was found between peak serum VEGF concentration and peak endostatin concentration. VEGF/endostatin ratio at day 1 and day 3 after AIS significantly correlated with circulating EPCs numbers at day 5 (P < 0.001) and day 7 post-stroke (P < 0.001). ROC curve analysis suggested that circulating EPCs number at day 7 had a significantly predictive power for good prognosis. VEGF and endostatin may mediate EPCs proliferation in the early phase of ischemic stroke, and the circulating EPCs levels can be a predictor of clinical outcome in AIS.

Efficacy and safety comparison of DL-3-n-butylphthalide and Cerebrolysin: Effects on neurological and behavioral outcomes in acute ischemic stroke.

Cerebrolysin and DL-3-n-butylphthalide (NBP) have each shown neuroprotective efficacy in preclinical models of acute ischemic stroke (AIS) and passed clinical trials as therapeutic drugs for AIS. The present study was a clinical trial to assess and compare the efficacy and safety of NBP and Cerebrolysin in the reduction of neurological and behavioral disability following AIS. A randomized, double-blind trial was conducted with enrolment of 60 patients within 12 h of AIS. In addition to routine treatment, patients were randomly assigned to receive a 10-day intravenous administration of NBP, Cerebrolysin or placebo. National Institutes of Health Stroke Scale (NIHSS) and Barthel Index (BI) scores were used to evaluate the efficacy of the treatment in the patients with AIS at 11 and 21 days after the initiation of therapy. Adverse events were also analyzed among the three groups. After 10 days of treatment with NBP or Cerebrolysin, the NIHSS and BI scores at day 21 showed statistical differences compared with those in the placebo group (P<0.05). The improvements of NIHSS and BI scores in the NBP and Cerebrolysin groups were higher than those in the placebo group at days 11 and 21 (P<0.05). A statistically significant difference in the improvement of 21-day NIHSS scores was observed between the two treatment groups (P<0.05). No significant difference was found among the three groups with regard to the rate of adverse events. Favorable outcomes and good safety were observed in the patients with moderate AIS treated with NBP or Cerebrolysin. The results indicate that NBP may be more effective than Cerebrolysin in improving short-term outcomes following AIS. This trial is registered at ClinicalTrials.gov with clinical trial identifier number NCT02149875.

Relationships between CETP genetic polymorphisms and Alzheimer's disease risk: a meta-analysis.

This meta-analysis was performed to evaluate the relationships between single-nucleotide polymorphisms in the CETP gene and the risk of Alzheimer's disease (AD). The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched from inception through October 1, 2013, without language restrictions. Nine case-control studies with a total of 2172 AD patients and 8017 healthy controls were involved in this meta-analysis. Two common polymorphisms (rs708272 T>C and rs5882 A>G) in the CETP gene were assessed. Our meta-analysis results showed that CETP rs5882 A>G polymorphism might increase the risk of AD (A allele vs. G allele: odds ratio [OR]=1.11, 95% confidence interval [95% CI]=1.02-1.21, p=0.014; AA+AG vs. GG: OR=1.28, 95% CI=1.07-1.52, p=0.006; AA vs. GG: OR=1.32, 95% CI=1.10-1.70, p=0.003; AA vs. AG: OR=1.25, 95% CI=1.03-1.50, p=0.020; respectively). However, we found no correlations of CETP rs708272 T>C polymorphism with AD risk (all p>0.05). Subgroup analysis by ethnicity suggested positive associations between CETP rs5882 A>G polymorphism and an increased risk of AD among Caucasians (A allele vs. G allele: OR=1.10, 95% CI=1.01-1.21, p=0.014; AA+AG vs. GG: OR=1.34, 95% CI=1.06-1.69, p=0.015; AA vs. GG: OR=1.35, 95% CI=1.07-1.70, p=0.011; respectively), but not among Asians (all p>0.05). No associations were found between CETP rs708272 T>C polymorphism and AD risk among both Asians and Caucasians (all p>0.05). Our findings provide empirical evidence that CETP rs5882 A>G polymorphism may contribute to susceptibility to AD, especially among Caucasians. However, CETP rs708272 T>C polymorphism does not seem to be an important determinant in the pathogenesis of AD.

Expression of basic fibroblast growth factor, protein kinase C and members of the apoptotic pathway in skeletal muscle of streptozotocin-induced diabetic rats.

This study investigated the potential mechanisms that may underlie diabetes induced amyoatrophy. Sprague-Dawley rats were either injected intraperiotneally with STZ (test group; N=8) to induce diabetic-like symptoms (blood glucose level ≥16.65mmol/L) or with buffer (control group; N=8). Differences in muscle structure between the STZ-induced diabetic and control groups were evaluated by histochemistry. Protein and mRNA levels of basic FGF (bFGF), bax, bcl-2, and caspase 3 in skeletal muscle were compared between the 2 groups using immunohistochemistry and quantitative PCR, respectively. Serum level of insulin and protein kinase C (PKC) were measured by competitive RIA and ELISA, respectively. Unlike control animals, the skeletal muscle fibers from STZ-induced diabetic animals were broken and pyknotic, the sarcomeric structure disrupted, and mild hyperplasia of interstitial adipose tissues was detected. The serum level of PKC was higher (P=0.003) and the protein and mRNA levels of bFGF in skeletal muscle were lower (P=0.001) in STZ-induced diabetic versus control animals. Protein and mRNA levels of the apoptosis promoting genes caspase-3 and bax were higher in skeletal muscle from STZ-induced diabetic rats as compared to control animals (P<0.001 and P=0.037, respectively), while mRNA and protein levels of bcl-2, an inhibitor of apoptosis, was lower in STZ-induced diabetic rats versus control animals (P=0.026). Increasing apoptosis in skeletal muscle from STZ-induced diabetic rats was further demonstrated by TNNEL assay. Our findings suggest that enhanced PKC levels, reduction of bFGF expression, and increased in apoptosis might be associated with the development of diabetes-induced myoatrophy.

Effect of chronic hypoxia on contents of urotensin II and its functional receptors in rat myocardium.

The cyclic peptide urotensin II (UII) has recently been cloned in mammals and reported to constrict rat pulmonary arteries potently. An enhanced maximal response was shown in rats exposed to chronic hypoxia. The aim of this study was to investigate changes in plasma and myocardial UII levels and its receptor sites in crude sarcolemma of ventricles from chronic hypoxic rats. We observed that rats exposed to chronic hypoxia for 4 weeks developed pulmonary hypertension and right ventricular hypertrophy. Compared with controls, the UII content in hypoxic rats was increased by 97.5% (45.24 +/- 7.1 vs. 22.9 +/- 3.24pg/mg protein, P < 0.01) in the right ventricle and 33.2% (24.89 +/- 0.99 vs. 18.68 +/- 2.04pg/mg protein, P < 0.01) in the left ventricle, respectively. However, there was no significant difference in plasma (27.44 +/- 3.11 vs. 27.82 +/- 5.57pg/ml, P > 0.05) and lung tissue levels (34.03 +/- 4.63 vs. 33.74 +/- 4.06 pg/ mg protein, P > 0.05) between the control and hypoxic groups. The time course of the binding of [125I]UII to crude ventricular sarcolemma was specific and time dependent. Scatchard plot analysis of the data demonstrated that the maximal number of specific binding sites (Bmax) in both the right and left ventricles was upregulated in the hypoxic group. Moreover, Bmax in the right ventricular specimens was upregulated to a greater extent than in the left ventricle (increased by 114% and 25% in the right and left ventricles, respectively, compared with control group, P < 0.01). In contrast, the UII binding affinity in right and left ventricular membranes from hypoxic rats was decreased (the dissociation constant Kd) increased by 20% and 33%, respectively compared with controls, P < 0.01). These results indicate that UII may act as an autocrine and/or paracrine hormone rather than as a circulating hormone, playing important roles in the development of ventricular hypertrophy induced by chronic hypoxia, and that the pathophysiological significance of UII in pulmonary and cardiovascular alteration induced by chronic hypoxia deserves further investigation.