Dl-3-n-butylphthalide activates Nrf2, inhibits ferritinophagy, and protects MES23.5 dopaminergic neurons from ferroptosis.

Ferroptosis, a newly identified iron-dependent form of cell death, has recently been implicated in the pathogenesis of Parkinson's disease (PD). Dl-3-n-butylphthalide (NBP) attenuates behavioral and cognitive deficits in animal models of PD. However, the potential of NBP to prevent dopaminergic neuron death by suppressing ferroptosis has rarely been explored. In this study, we aimed to investigate the effects of NBP on ferroptosis in erastin-induced dopaminergic neurons (MES23.5 cells) and the underlying mechanisms involved in these effects. Our results demonstrated that erastin significantly decreased viability of MES23.5 dopaminergic neurons in a dose-dependent manner, which was reversible by ferroptosis inhibitors. We further verified that NBP protected erastin-treated MES23.5 cells from death by inhibiting ferroptosis. Erastin increased the mitochondrial membrane density, caused lipid peroxidation, and decreased GPX4 expression in MES23.5 cells, which could be reversed by NBP preconditioning. NBP pretreatment suppressed erastin-induced labile iron accumulation and reactive oxygen species generation. Moreover, we demonstrated that erastin significantly reduced FTH expression, and pre-administration with NBP promoted Nrf2 translocation into the nucleus and increased the protein level of FTH. Additionally, the expression of LC3B-II in MES23.5 cells pretreated with NBP before administration of erastin was lower than that in cells treated with erastin alone. NBP reduced colocalization of FTH and autophagosomes in MES23.5 cells exposed to erastin. Finally, erastin gradually inhibited NCOA4 expression in a time-dependent manner, which was reversible by NBP pretreatment. Taken together, these results indicated that NBP suppressed ferroptosis via regulating FTH expression, which was achieved by promoting Nrf2 nuclear translocation and inhibiting NCOA4-mediated ferritinophagy. As such, NBP may be a promising therapeutic agent for the treatment of neurological diseases associated with ferroptosis.

Preparation and Synergistic Effect of Biomimetic Poly(lactic acid)/Graphene Oxide Composite Scaffolds Loaded with Dual Drugs.

To promote the bone repair ability of drug-loaded scaffolds, poly(lactic acid) (PLA)/graphene oxide (GO)/Salvianolic acid B (Sal-B)/aspirin (ASA) dual drug-loaded biomimetic composite scaffolds were prepared. The results showed that the addition of these two drugs delayed the gel formation of the composite system, but a biomimetic nanofiber structure could still be obtained by extending the gel time. The addition of Sal-B increased the hydrophilicity of the scaffold, while an increase in ASA reduced the porosity. Dual drug-loaded scaffolds had good haemocompatibility and synergically promoted the proliferation of MC3T3-E1 cells and enhanced alkaline phosphatase activity. Sustained-release experiments of the two drugs showed that the presence of ASA slowed the cumulative release of Sal-B, while Sal-B promoted the release of ASA. Kinetic modeling showed that the release of both drugs conforms to the Korsmeyer-Peppas model, but Sal-B conforms to the Fick diffusion mechanism and ASA follows Fick diffusion and carrier swelling/dissolution.

Preparation and sustained-release properties of poly(lactic acid)/graphene oxide porous biomimetic composite scaffolds loaded with salvianolic acid B.

Biomimetic scaffolds loaded with drugs can improve the osteogenesis and neovascularisation of scaffolds. A series of PLA/GO/Sal-B drug-loaded scaffolds was prepared by thermally induced phase separation. The addition of Sal-B increased the diameter of the fibres, but the scaffold showed a porous nanofibrous structure after drug release. X-ray diffraction results showed that the addition of Sal-B did not affect the formation of the nanofibre biomimetic structure of the scaffold. FTIR results indicated a certain interaction between Sal-B and PLA/GO. Water absorption and porosity test results revealed that the scaffolds had good hydrophilicity and appropriate porosity. The addition of Sal-B was also conducive to the formation of sediments possibly due to the good water solubility of Sal-B itself. The prepared scaffolds had good blood compatibility and cytocompatibility, and a small additional amount of Sal-B could significantly promote cell proliferation and alkaline phosphatase activity. Their sustained release performance indicated that the biomimetic scaffolds had controlled the release of Sal-B. The kinetic model showed that the PLA/GO/Sal-B drug-loaded biomimetic scaffolds followed the diffusion mechanism.

Proteome-wide analysis of the hippocampus in adolescent male mice with learning and memory impairment caused by chronic ethanol exposure.

Alcohol consumption may cause various impairments in the brain. The hippocampus is particularly vulnerable to alcohol exposure, which may cause learning and memory deficits. Recently, proteomics analysis has become a popular approach to explore the pathogenesis of various diseases. The present study was conducted to investigate protein expression alteration in the hippocampus and to identify the molecular mechanisms underlying ethanol-induced learning and memory impairments. Mouse models of chronic ethanol intoxication were established by intragastrical administration for 28 consecutive days, and hippocampal neuronal damage was assessed by Nissl staining. Recognition memory was evaluated by Novel object recognition and Morris water maze tests, and hippocampus tissues were collected for label-free quantitative proteomics and analyzed using bioinformatics methods. Our study showed that chronic ethanol exposure prompted marked changes in protein expression in the hippocampus. We identified 32 differentially expressed proteins, of which 21 were upregulated and 11 downregulated. Gene Ontology analysis suggested that the identified differentially proteins were mainly involved in cytoskeleton and signal transduction mechanisms. Further verification using Western blotting and real-time quantitative PCR revealed that the hippocampal CTSL (cathepsin L), and PVALB (Parvalbumin) showed strongest expression changes, the latter being specifically expressed in GABAergic interneurons. These two proteins might serve as candidate protein biomarkers, providing new prospects for the diagnosis and treatment of ethanol-induced learning and memory disorders.

Unsaturated Polyester Resin as a Nonformaldehyde Adhesive Used in Bamboo Particle Boards.

Unsaturated polyester resin (UPR) with good chemical resistance, excellent mechanical properties, and formaldehyde-free shows great potentials in the wood industry. In this study, the mechanical strength, thermostability, dynamic thermomechanical property, and interfacial bonding of bamboo particle boards (BPBs) made from UPR adhesives with toluene diisocyanate (TDI) as the coupling agent were explored. The results showed that covalent bonds were formed among TDI, bamboo particles, and UPR, which could significantly enhance the mechanical strength. The internal bonding strength, modulus of elasticity, and modulus of rupture of treated BPBs were 1.36, 3010, and 19.6 MPa with the increment of 1250, 514, and 833%, respectively, compared to the control samples. Also, the thickness swelling rate of the BPB was 4.6%, much lower than that of the control, with a decrease of 92%. The thermostability of the treated BPB was also improved. As a result, the BPB using UPR as the adhesive and TDI as the coupling agent shows better usability, higher efficiency, and excellent mechanical strength.

Plasma Retinol Binding Protein 4 as a Biomarker for Detecting Progressive Stroke and Prediction of Early Prognosis in Patients with Acute Ischemic Stroke.

Aim and Purpose: Progressive Stroke (PS) lacks effective treatment measures and leads to serious disability or death. Retinol binding protein 4 (RBP4) could be closely associated with acute ischemic stroke (AIS). We aimed to explore plasma RBP4 as a biomarker for detecting the progression in patients with AIS. METHODS: Participants of this retrospective study were 234 patients with AIS within the 48 h onset of disease. The primary endpoint was to ascertain if there was PS through the National Institute of Health stroke scale (NIHSS); the early prognosis was confirmed through the modified Rankin scale score (mRS) at discharge or 14 days after the onset of stroke, and the significance of demographic characteristics and clinical data was determined. RESULTS: In this study, 43 of 234 patients demonstrated PS. The level of plasma RBP4 in patients with progressive stroke was significantly lower (29 mg/L, 22.60-40.38 mg/L) than that without progression (38.70 mg/L, 27.28-46.40 mg/L, P = 0.003). In patients with lower plasma RBP4, the proportion of patients with progression (χ2 = 9.63, P = 0.008) and with mRS scores ≥2 (χ2 = 6.73, P = 0.035) was significantly higher. Multivariate logistic regression analysis showed that a lower RBP4 level on admission was an independent risk factor for progressive stroke during hospitalization with an OR value of 2.70 (P = 0.03, 95% CI: 1.12-6.52). CONCLUSION: A low plasma RBP4 level on admission could be an independent risk factor of PS during hospitalization.

Preparation and characterization of a novel polylactic acid/hydroxyapatite composite scaffold with biomimetic micro-nanofibrous porous structure.

Combining synthetic polymer scaffolds with inorganic bioactive factors is widely used to promote the bioactivity and bone conductivity of bone tissue. However, except for the chemical composition of scaffold, the biomimetic structure also plays an important role in its application. In this study, we report the fabrication of polylactic acid/hydroxyapatite (PLA/HA) composite nanofibrous scaffolds via phase separation method to mimic the native extracellular matrix (ECM). The SEM analysis showed that the addition of HA dramatically impacted the morphology of the PLA matrix, which changed from 3D nanofibrous network structure to a disorderly micro-nanofibrous porous structure. At the same time, HA particles could be evenly dispersed at the end of the fiber. The FTIR and XRD demonstrated that there was not any chemical interaction between PLA and HA. Thermal analyses showed that HA could decrease the crystallization of PLA, but improve the thermal decomposition temperature of the composite scaffold. Moreover, water contact angle analysis of the PLA/HA composite scaffold demonstrated that the hydrophilicity increased with the addition of HA. Furthermore, apatite-formation ability tests confirmed that HA could not only more and faster induced the deposition of weak hydroxyapatite but also induced specific morphology of HA.

Rifampicin attenuates rotenone-induced inflammation via suppressing NLRP3 inflammasome activation in microglia.

A growing body of evidence has supported that environmental factors, such as exposure to heavy metal and pesticides, play an important role in the pathogenesis of Parkinson׳s disease (PD). Rotenone, the active ingredient in various pesticides, has been identified as an inducer of PD. It has been revealed that rotenone induces activation of microglia and generation of pro-inflammatory factors in PD. Our previous studies demonstrated that rifampicin possessed neural protective effect in PD. In this study, we aimed to study the effect of rifampicin on the inflammation induced by rotenone in microglia and the underlying mechanisms. Results demonstrated that rifampicin pretreatment significantly reduced rotenone-induced cytotoxicity and gene expression of IL-1ß in BV2 microglia. Moreover, western blot analysis verified that rifampicin pretreatment suppressed NLRP3 inflammasome activation via inhibiting caspase-1 cleavage and protein expression of NLRP3. As it is indicated that reactive oxidative stress (ROS) is one of the activators for NLRP3 inflammasome, we further employed 2',7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining and Rhodamine123 staining to detect intracellular ROS and mitochondrial membrane potential (MMP), respectively. Results confirmed that rifampicin obviously reduced intracellular ROS and reversed loss of MMP in BV2 cells treated by rotenone. Taken together, our data indicate that rifampicin pretreatment inhibits maturation of IL-1ß and neuroinflammation induced by rotenone via attenuating NLRP3 inflammasome activation. Rifampicin might emerge as a promising candidate for modulating neuroinflammation in PD.

Fabrication of polycaprolactone nanofibrous scaffolds by facile phase separation approach.

Three-dimensional polycaprolactone (PCL) scaffolds with spherulite and nanofibrous structures were fabricated for the first time by thermally induced phase separation from a ternary PCL/dioxane/water system. Moreover, the effects of polymer concentration, aging temperature and the ratio of dioxane to water on the morphology of nanofibrous scaffolds were investigated. The result revealed that gelation, aging temperature, and ratio of solvents significantly influenced the formation of the unique spherulite and nanofibrous structures. The apatite-formation ability test showed relatively rapid growth of carbonate hydroxyapatite in the nanofibrous PCL scaffold with macropore compared to the other two scaffolds with smooth structure and nanofibrous structure without macropore, respectively, indicating good apatite-formation ability of the macroporous and nanofibrous PCL scaffolds.

Evaluating team-based, lecture-based, and hybrid learning methods for neurology clerkship in China: a method-comparison study.

BACKGROUND: Neurology is complex, abstract, and difficult for students to learn. However, a good learning method for neurology clerkship training is required to help students quickly develop strong clinical thinking as well as problem-solving skills. Both the traditional lecture-based learning (LBL) and the relatively new team-based learning (TBL) methods have inherent strengths and weaknesses when applied to neurology clerkship education. However, the strengths of each method may complement the weaknesses of the other. Combining TBL with LBL may produce better learning outcomes than TBL or LBL alone. We propose a hybrid method (TBL + LBL) and designed an experiment to compare the learning outcomes with those of pure LBL and pure TBL. METHODS: One hundred twenty-seven fourth-year medical students attended a two-week neurology clerkship program organized by the Department of Neurology, Sun Yat-Sen Memorial Hospital. All of the students were from Grade 2007, Department of Clinical Medicine, Zhongshan School of Medicine, Sun Yat-Sen University. These students were assigned to one of three groups randomly: Group A (TBL + LBL, with 41 students), Group B (LBL, with 43 students), and Group C (TBL, with 43 students). The learning outcomes were evaluated by a questionnaire and two tests covering basic knowledge of neurology and clinical practice. RESULTS: The practice test scores of Group A were similar to those of Group B, but significantly higher than those of Group C. The theoretical test scores and the total scores of Group A were significantly higher than those of Groups B and C. In addition, 100% of the students in Group A were satisfied with the combination of TBL + LBL. CONCLUSIONS: Our results support our proposal that the combination of TBL + LBL is acceptable to students and produces better learning outcomes than either method alone in neurology clerkships. In addition, the proposed hybrid method may also be suited for other medical clerkships that require students to absorb a large amount of abstract and complex course materials in a short period, such as pediatrics and internal medicine clerkships.

Correlation between the changes in ambulatory electroencephalography findings and epilepsy recurrence after medication withdrawal among the population in southern China.

Patients suffering from epilepsy need long-term medication. However, after the epilepsy is completely under control, the recurrence rate is high once the drug dose is reduced gradually. The present study investigated the possible correlation between the changes shown by ambulatory electroencephalography (EEG) and epilepsy recurrence after medication withdrawal, and assessed the value of ambulatory EEG findings in predicting the recurrence of epilepsy after medication withdrawal, in 265 patients from Southern China followed up for 5 years. Anticonvulsants were withdrawn until onset had been controlled thoroughly for over 3 years and ambulatory EEG detected no abnormalities. Ambulatory EEG was performed at least once per year, and findings at the first visit, during treatment, and before and after medication withdrawal were compared and analyzed. There were 47 patients with recurrent epilepsy in this study. Patients with normal ambulatory EEG findings at the first visit and during treatment had lower recurrence rate (about 8.1%) compared to patients with epileptic waves (25.0%), and patients with focal epileptic waves in the temporal, occipital, frontal, and parietal lobes, or in multiple areas was even higher. Patients with epileptic waves also showed higher clinical recurrence rate during the follow-up period. Abnormal ambulatory EEG findings are an important indicator of epileptic recurrence, and is of great value in predicting the recurrence of epilepsy after medication withdrawal.