Pretreatment with Methylene Blue Protects Against Acute Seizure and Oxidative Stress in a Kainic Acid-Induced Status Epilepticus Model.

BACKGROUND The aim of the present study was to investigate the potential anticonvulsant effect of methylene blue (MB) in a kainic acid (KA)-induced status epilepticus (SE) model. The effects of MB on levels of oxidative stress and glutamate (Glu) also were explored. MATERIAL AND METHODS Sixty C57BL/6 mice were randomly divided into 5 equal-sized groups: (1) controls; (2) KA; (3) MB 0.5 mg/kg+KA; (4) MB 1 mg/kg+KA; and (5) vehicle+KA. The SE model was established by intra-amygdala microinjection of KA. Behavioral observations and simultaneous electroencephalographic records of the seizures in different groups were analyzed to determine the potential anticonvulsant effect of MB. The influences of MB on oxidative stress markers and glutamate were also detected to explore the possible mechanism. RESULTS MB afforded clear protection against KA-induced acute seizure, as measured by the delayed latency of onset of generalized seizures and SE, decreased percentage of SE, and increased survival rate in mice with acute epilepsy. MB markedly increased the latency to first onset of epileptiform activity and decreased the average duration of epileptiform events, as well as the percentage of time during which the epileptiform activity occurred. Administration of MB prevented KA-induced deterioration of oxidative stress markers and Glu. CONCLUSIONS MB is protective against acute seizure in SE. This beneficial effect may be at least partially related to its potent antioxidant ability and influence on Glu level.

[Antioxidant effects of celastrol against hydrogen peroxide-induced oxidative stress in the cell model of amyotrophic lateral sclerosis].

To investigate the anti-oxidative effect of celastrol on H2O2-induced oxidative stress in the cell model of amyotrophic lateral sclerosis (ALS) and its molecular mechanism, NSC34 motor neuron-like cells were transfected with EGFP-G93A-SOD1 plasmid and used as in vitro ALS cell model. SOD1G93A transfected NSC34 cells were treated with different doses of H2O2 and celastrol. The survival rate of the cells was detected by CCK-8 assay, and malondialdehyde (MDA) content was detected by corresponding kit. The mRNA expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione S-transferases (GST) were detected by real-time PCR. The activation of intracellular MEK/ERK and PI3K/Akt signal pathways was detected by Western blot. The results showed that pre-incubation of celastrol (50 nmol/L) for 4 h prior to H2O2 (10 µmol/L) co-treatment for another 24 h significantly attenuated H2O2-induced cell death and MDA level in SOD1G93A transfected NSC34 cells. Real-time PCR showed that the mRNA expressions of GCLC and GST were enhanced with pre-incubation of celastrol. Celastrol quickly induced phosphorylation of ERK1/2 and Akt within 30 min and 1 h respectively in SOD1G93A transfected NSC34 cells. Pharmacological inhibitors of MEK (PD98059, 10 µmol/L) or Akt (MK2206, 10 µmol/L) could reverse the phosphorylation of ERK1/2 and Akt, and abolish up-regulation of GCLC and GST induced by celastrol at mRNA levels. Taken together, we conclude that celastrol exerts a beneficial antioxidant effect in SOD1G93ANSC34 cells, which might be dependent on MEK/ERK and PI3K/Akt signaling pathway activation.

Brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor inhibit ferrous iron influx via divalent metal transporter 1 and iron regulatory protein 1 regulation in ventral mesencephalic neurons.

Iron accumulation is observed in the substantia nigra of patients with Parkinson's disease. However, it is unknown whether neurotrophic factors, brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) participate in the modulation of neuronal iron metabolism. Here, we investigated the effects and underlying mechanisms of BDNF and GDNF on the iron influx process in primary cultured ventral mesencephalic neurons. 6-hydroxydopamine-induced enhanced ferrous iron influx via improper up-regulation of divalent metal transporter 1 with iron responsive element (DMT1+IRE) was consistently relieved by BDNF and GDNF. Both the mRNA and protein levels of DMT1+IRE were down-regulated by BDNF or GDNF treatment alone. We further demonstrated the involvement of iron regulatory protein 1 (IRP1) in BDNF- and GDNF-induced DMT1+IRE expression. Extracellular-regulated kinase 1/2 (ERK1/2) and Akt were activated and participated in these processes. Inhibition of ERK1/2 and Akt phosphorylation abolished the down-regulation of IRP1 and DMT1+IRE induced by BDNF and GDNF. Taken together, these results show that BDNF and GDNF ameliorate iron accumulation via the ERK/Akt pathway, followed by inhibition of IRP1 and DMT1+IRE expression, which may provide new targets for the neuroprotective effects of these neurotrophic factors.

Causal relationship between feelings and cognitive decline: An univariable and multivariable Mendelian randomization study.

BACKGROUND: While the impact of depression on cognition is well-documented, the relationship between feelings and cognition has received limited attention. AIM: To explore the potential association between feelings and cognition with a two-sample Mendelian randomization (MR) analysis. METHODS: Our analysis utilized genome-wide association data on various feelings (fed-up feelings, n = 453071; worrier/anxious feelings, n = 450765; guilty feelings, n = 450704; nervous feelings, n = 450700; sensitivity/hurt feelings, n = 449419; miserableness, n = 454982; loneliness/isolation, n = 455364; happiness, n = 152348) in the European population and their impact on cognitive functions (intelligence, n = 269867). Conducting a univariable MR (UVMR) analysis to assess the relationship between feelings and cognition. In this analysis, we applied the inverse variance weighting (IVW), weighted median, and MR Egger methods. Additionally, we performed sensitivity analysis (leave-one-out analysis), assessed heterogeneity (using MR-PRESSO and Cochran's Q test), and conducted multiple validity test (employing MR-Egger regression). Subsequently, a multivariable MR (MVMR) analysis was employed to examine the impact of feelings on cognition. IVW served as the primary method in the multivariable analysis, complemented by median-based and MR-Egger methods. RESULTS: In this study, UVMR indicated that sensitivity/hurt feelings may have a negative causal effect on cognition (OR = 0.63, 95%CI: 0.43-0.92, P = 0.017). After adjustment of other feelings using MVMR, a direct adverse causal effect on cognition was observed (ORMVMR = 0.39, 95%CI: 0.17-0.90, PMVMR = 0.027). While a potential increased risk of cognitive decline was observed for fed-up feelings in the UVMR analysis (ORUVMR = 0.64, 95%CI: 0.42-0.97, PUVMR = 0.037), this effect disappeared after adjusting for other feelings (ORMVMR = 1.42, 95%CI: 0.43-4.74, PMVMR = 0.569). These findings were generally consistent across MV-IVW, median-based, and MR-Egger analyses. MR-Egger regression revealed pleiotropy in the impact of worrier/anxious feelings on cognition, presenting a challenge in identifying the effect. Notably, this study did not demonstrate any significant impact of guilty feelings, nervous feelings, miserableness, or loneliness/isolation on cognition. Due to a limited number of instrumental variables for happiness, this study was unable to analyze the relationship between happiness and cognition. CONCLUSION: This MR study finds that sensitivity/hurt feelings are associated with cognitive decline, while the link between worrier/anxious feelings and cognition remains inconclusive. Insufficient evidence supports direct associations between happiness, guilty feelings, nervous feelings, miserableness, loneliness/isolation, and cognition.

Mechanistic insights into the effects of diuron exposure on Alexandrium pacificum.

Diuron (N-(3,4-dichlorophenyl)-N,N­dimethylurea, DCMU), a ureic herbicide, is extensively used in agriculture to boost crop productivity; however, its extensive application culminates in notable environmental pollution, especially in aquatic habitats. Therefore, the present study investigated the effect of diuron on the dinoflagellate Alexandrium pacificum, which is known to induce harmful algal blooms (HAB), and its potential to biodegrade DCMU. Following a four-day DCMU exposure, our results revealed that A. pacificum proficiently assimilated DCMU at concentrations of 0.05 mg/L and 0.1 mg/L in seawater, attaining a complete reduction (100 % efficiency) after 96 h for both concentrations. Moreover, evaluations of paralytic shellfish toxins content indicated that cells subjected to higher DCMU concentrations (0.1 mg/L) exhibited reductions of 73.4 %, 86.7 %, and 75 % in GTX1, GTX4, and NEO, respectively. Exposure to DCMU led to a notable decrease in A. pacificum's photosynthetic efficacy, accompanied by increased levels of reactive oxygen species (ROS) and suppressed cell growth, with a growth inhibition rate of 41.1 % at 72 h. Proteomic investigations pinpointed the diminished expression levels of specific proteins like SxtV and SxtW, linked to paralytic shellfish toxins (PSTs) synthesis, as well as key proteins associated with Photosystem II, namely PsbA, PsbD, PsbO, and PsbU. Conversely, proteins central to the cysteine biosynthesis pathways exhibited enhanced expression. In summary, our results preliminarily resolved the molecular mechanisms underlying the response of A. pacificum to DCMU and revealed that DCMU affected the synthesis of PSTs. Meanwhile, our data suggested that A. pacificum has great potential in scavenging DCMU.

6-Hydroxydopamine promotes iron traffic in primary cultured astrocytes.

It is well known that disrupted brain iron homeostasis was involved in Parkinson's disease. We previously reported 6-hydroxydopamine (6-OHDA) could enhance iron influx and attenuate iron efflux process, thus promote iron accumulation in neurons. Astrocytes, the major glial cell type in the central nervous system, are largely responsible for iron distribution in the brain. However, how iron metabolism changes in astrocytes with 6-OHDA treatment are not fully elucidated. In the present study, we first observed that both iron influx and efflux were enhanced with 10 µM 6-OHDA treatment for 24 h in primary cultured astrocytes. In accordance with these iron traffic modulations, both mRNA and protein levels of iron importer divalent metal transporter 1 with iron responsive element (DMT1+IRE) and exporter ferroportin 1 (FPN1) were up-regulated in these cells. L-ferritin mRNA levels were increased. Iron regulatory protein 1 (IRP1) showed a dynamic regulation with 6-OHDA treatment, as indicated by a moderate up-regulation at 12 h, however, down-regulation at 24 h. We further demonstrated that 6-OHDA treatment could induce activation of nuclear factor-kappaB (NF-κB) p65. IκBα activation inhibitor BAY11-7082 fully blocked 6-OHDA induced NF-κB p65 phosphorylation and DMT1 + IRE up-regulation. These results suggest that 6-OHDA might promote iron transport rate in astrocytes by regulating iron transporters, IRP1 expression and NF-κB p65 activation, indicating a different response between neurons and astrocytes.

Metformin inhibits proliferation and promotes apoptosis of HER2 positive breast cancer cells by downregulating HSP90.

PURPOSE: To investigate the effects and the possible molecular mechanisms of metformin on HER2 positive breast cancer cells. METHODS: SK-BR-3 HER2 positive breast cancer cells were treated with different concentrations of metformin. The growth inhibitory rate of the cells was calculated by MTT assay, apoptosis was detected by flow cytometry, and the expression level of heat shock protein 90 (HSP90) was performed by Western blot analysis. A control group consisted of cells treated with PBS. RESULTS: With increased concentrations of metformin, cell growth inhibitory rates increased. The growth inhibitory rates with 0.5 mM, 2mM or 8mM metformin were significantly higher compared with the control group (p<0.05). Apoptosis in the metformin treated cells was also significantly higher compared with the control group (p=0.003). The expression level of HSP90 in the metformin group was significantly lower than that in the control group. CONCLUSION: Metformin can inhibit the proliferation and promote apoptosis of HER2 positive breast cancer cells,which is maybe related to inhibition of HSP90.

[Effect of Toxoplasma gondii infection on the embryonic neural stem cells in rats].

OBJECTIVE: To investigate the effect of Toxoplasma gondii infection on the proliferation, differentiation and migration of the embryonic neural stem cells (NSCs) in early pregnancy of rat. METHODS: Twelve pregnant Sprague-Dawley rats were randomly divided into control and infection groups. Rats in the infection group were each inoculated intraperitoneally with 1 x 10(5) T. gondii RH strain tachyzoites at day 1 (E1 day). Same amount of physiological saline was intraperitoneally injected for rats in control group. At E5 day, blood samples were taken from caudal vein and Giemsa staining of blood cells was performed to find T. gondii. At E9, E10 and E11 day, two rats in each group per time point were sacrificed and reverse transcription PCR (RT-PCR) was performed to detect B1 gene expression of T. gondii in amniotic fluid to confirm T. gondii infection. NSCs were cultured in vitro. The proliferation level was detected by methyl thiazolyl tetrazolium (MTT) assay. After differentiation culture of NSCs, the immunofluorescence assay was conducted to detect the expression of nestin, microtubule-associated protein 2 (MAP2) and glial fibrillary acidic protein (GFAP) to calculate the ratio of NSCs which differentiated to neurons and astrocytes. The embryonic nerve tissues at E9, E10 and E11 day in each group were taken to make frozen sections. The immunofluorescence assay was carried out to detect the expression of neuronal cell adhesion molecule (NCAM) in the nerve tissues at different developmental stages. RESULTS: Both the results of blood smears and RT-PCR confirmed that the pregnant rats and embryos were all infected by T. gondii in infection group. The morphology of the cultured NSCs under microscope was consistent with the characteristics of the normal NSCs. In addition, the NSC biomarker nestin protein was stained positive. The MTT assay showed that the proliferation level was lower in infection group than that of the control, and statistical differences were found between the two groups at day 3 and 4 after passages (P < 0.05). The immunofluorescence staining of MAP2 and GFAP showed that the percentage of neuron differentiation was 15.15% (55/363) in control group and 8.73% (31/355) in infection group, respectively, with a statistical difference (P < 0.05), and the percentage of astrocyte differentiation was 53.35% (199/374) and 67.48% 249/369), respectively (P > 0.05). In both groups, NCAM protein was found expressed at E9, E10 and E11 day in embryo nerve tissues. The fluorescence became stronger with time. The expression level in control group was significantly higher than that in infection group (P < 0.01). CONCLUSION: T. gondii infection at early gestation may inhibit the proliferation, differentiation and migration of neural stem cells in rats.

Histological analysis of human pancreatic carcinoma following irreversible electroporation in a nude mouse model.

AIM: To determine changes in the morphology and function of pancreatic cancer cells after irreversible electroporation (IRE) treatment, and to explore the clinical significance of IRE treatment for pancreatic cancer providing an experimental basis for the clinical application of IRE treatment. METHODS: IRE was carried out in an athymic nude mouse model of pancreatic carcinoma generated with human pancreatic cancer cells 1. In therapy groups, IRE electrodes were inserted with 90 pulses per second at 800 V/cm applied to ablate the targeted tumor tissues. Histological assessment of the affected tissue was performed by hematoxylin and eosin staining (HE). Quantification of cell proliferation and apoptosis was performed by evaluating Ki67 and caspase-3 levels, respectively. Flow cytometry was used to assess cell apoptosis. Ultrasound imaging was carried out to evaluate IRE treatment results. Pathological correlation studies showed IRE is effective for the targeted ablation of pancreatic tumors in an orthotopic mouse model. RESULTS: IRE was efficacious in removing tumors in the orthotopic mouse model. The IRE-ablated zone displays characteristics of nude mouse models at different time-points as assessed by hematoxylin and eosin staining. Immunohistochemical analysis of samples from the pancreatic cancer models showed significantly enhanced caspase-3 cleavage and Ki67. Flow cytometry data corroborated the above findings that apoptosis in tumor cells was observed immediately on the first postoperative day, and with time the middle and late stages of apoptosis were observed. For ultrasound imaging studies, the IRE ablation zone became a hyperechoic area due to increasing inflammatory and immunologic cellular contents. CONCLUSION: IRE is a promising new approach for pancreatic cancer, with many potential advantages over conventional ablation techniques.

Pyridyl-Directed Cp*Rh(III)-Catalyzed B(3)-H Acyloxylation of o-Carborane.

An efficient pyridyl-directed Rh(III)-catalyzed o-carborane B(3)-H acyloxylation is reported. The B(3)-H bond is the most electron-deficient vertex on o-carborane whose functionalization is challenging. The combination of Cu(OH)2 and diverse carboxylic acids provides low cost and abundant acyloxyl sources which could lead to moderate to excellent yields.

Role of CXC chemokine receptor type 7 in carcinogenesis and lymph node metastasis of colon cancer.

Upregulated expression of the CXC chemokine receptor type 7 (CXCR7) promotes breast, lung and prostate cancer progression and metastasis. However, the role of CXCR7 in colon cancer has not been determined. We hypothesized that increased CXCR7 expression may contribute to human colon cancer occurrence and progression. Reverse transcription quantitative polymerase chain reaction and western blot analysis were performed on 34 malignant and 18 normal colon tissue specimens. The specimens were obtained from 19 male and 15 female patients, with a mean age of 52 years (range, 34-79 years). Of the 34 patients, 20 had lymph node metastases. None of the patients had received adjuvant radiotherapy or chemotherapy prior to surgery. This study demonstrated that CXCR7 levels were significantly higher in colon tumors compared with those in normal colon tissue (P﹤0.01). In addition, lymph node metastatic colon tumors exhibited significantly higher CXCR7 expression compared with non-metastatic tumors (P﹤0.01); however, there were no differences in CXCR7 expression among distinct histopathological types (well-differentiated vs. moderately-to-poorly differentiated adenocarcinoma, P﹥0.01). Therefore, the evidence obtained from the present study supports involvement of the upregulated CXCR7 expression in colon tumorigenesis and lymph node metastasis.