Thiacalix[4]arene-based complex with Co(II) ions as electrode modifier for simultaneous electrochemical determination of Cd(II), Pb(II), and Cu(II).

A complex [Co4(TCTA)2(H2O)8]∙10H2O (Co-TCTA) based on thiacalix[4]arene derivative has been synthesized for the first time using the solvothermal method. The glassy carbon electrode (GCE) modified with Co-TCTA (Co-TCTA/GCE) could simultaneously determine Cd2+, Pb2+, and Cu2+ at around - 0.75 V, - 0.60 V, and - 0.10 V (vs. ref. Ag/AgCl) and had good stability, selectivity, and reproducibility with relative standard deviation (RSD) of 4.4% for Cd2+, 1.4% for Pb2+, and 5.4% for Cu2+. Co-TCTA/GCE showed wide linear range of 0.4-8.0 µM for Cd2+, 0.4-7.0 µM for Pb2+, and 0.6-6.0 µM for Cu2+ when three ions were determined simultaneously. The limits of detection (LODs) of Cd2+, Pb2+, and Cu2+ were 0.071 µM, 0.022 µM, and 0.021 µM, respectively. Moreover, the sensor was used to determine three ions in lake water sample with satisfactory recoveries of 93.6-93.8% for Cd2+, 93.8-103.3% for Pb2+ and 94.6-95.3% for Cu2+. The good adsorption capacity of Co-TCTA and Co(II)/Co(0) circular mechanism on the surface of the electrode were proposed to enhance the electrochemical signals. This work enriched the theoretical research on the complexes for the determination of heavy metal ions.

Bilobalide inhibits inflammation and promotes the expression of Aß degrading enzymes in astrocytes to rescue neuronal deficiency in AD models.

The pathogenesis of Alzheimer's disease (AD) involves multiple cell types including endothelial cells, glia, and neurons. It suggests that therapy against single target in single cell type may not be sufficient to treat AD and therapies with protective effects in multiple cell types may be more effective. Here, we comprehensively investigated the effects of bilobalide on neuroinflammation and Aß degrading enzymes in AD cell model and mouse model. We find that bilobalide inhibits Aß-induced and STAT3-dependent expression of TNF-α, IL-1ß, and IL-6 in primary astrocyte culture. Bilobalide also induces robust expression of Aß degrading enzymes like NEP, IDE, and MMP2 to facilitate astrocyte-mediated Aß clearance. Moreover, bilobalide treatment of astrocyte rescues neuronal deficiency in co-cultured APP/PS1 neurons. Most importantly, bilobalide reduces amyloid and inflammation in AD mouse brain. Taken together, the protective effects of bilobalide in in vitro cultures were fully recapitulated in in vivo AD mouse model. Our study supports that bilobalide has therapeutic potential for AD treatment.

Correction: Melatonin-induced ApoE expression in mouse astrocytes protects endothelial cells from OGD-R induced injuries.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Melatonin-induced ApoE expression in mouse astrocytes protects endothelial cells from OGD-R induced injuries.

Stroke is a leading reason of death and long-term disability, and most studies mainly focus on efforts to protect neurons. However, failed clinical trials suggest that therapies against single target in neurons may not be sufficient and the involvement of endothelial cells and glial cells have been underestimated. Astrocytes are the major source of ApoE in the brain and endothelial cells express high level of ApoE receptors. Thus, ApoE may mediate the interaction between astrocytes and endothelial cells. To address whether and how ApoE-mediated astrocytes-endothelial cells interaction contributes to the pathogenesis of stroke, we used oxygen and glucose deprivation-reoxygenation (OGD-R) as a stroke model and investigated the effects of OGD-R on astrocytes-endothelial cell co-cultures in the current study. We find that OGD-R leads to various damages to endothelial cells, including compromised cell viability, increased ROS level, enhanced caspase activity, and higher apoptotic rate. Meanwhile, mouse astrocytes could secrete ApoE to activate PI3K/eNOS signaling in endothelial cells to prevent OGD-R induced injuries. In addition, OGD-R induces down-regulation of ApoE in astrocyte-endothelial cell co-cultures while melatonin restores astrocytic ApoE expression via pCREB pathway and protects endothelial cell in OGD-R treated co-cultures. Our study provides evidence that astrocytes could protect endothelial cells via ApoE in OGD-R condition and Melatonin could induce ApoE expression to protect endothelial cells.

DNA Aptamers Targeting BACE1 Reduce Amyloid Levels and Rescue Neuronal Deficiency in Cultured Cells.

ß-amyloid (Aß) plays an essential role in the pathogenesis of Alzheimer's disease (AD). Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is indispensable for Aß production, and knockout of BACE1 has no overt phenotypes in mouse. Thus, fine modulation of BACE1 may be a safe and effective treatment for AD patients. However, the large active site of BACE1 makes it challenging to target BACE1 with classical small-molecule inhibitors. DNA aptamer can have high affinity and specificity against diverse targets, and it provides an alternative strategy to target BACE1. In this study, we used a novel cell-systematic evolution of ligands by exponential enrichment (SELEX) strategy to select specific DNA aptamers optimized to target BACE1 under physiological status. After 17 rounds of selection, we identified two DNA aptamers against BACE1: BI1 and BI2. The identified aptamers interacted with BACE1 in pull-down assay, inhibited BACE1 activity in in vitro fluorescence resonance energy transfer (FRET) assay and HEK293-APP stable cell line, reduced Aß in the culture medium of HEK293-amyloid protein precursor (APP) stable cell line and APP-PS1 primary cultured neurons, and rescued Aß-induced neuronal deficiency in APP-PS1 primary cultured neurons. In contrast, the identified aptamers had no effect on α- or γ-secretase. In addition, cholesteryl tetraetylene glycol (TEG) modification further improved the potency of the identified aptamers. Our study suggests that it is feasible and effective to target BACE1 with DNA aptamers, and the therapeutic potential of the identified aptamers deserves further investigation.

Subcutaneous rotenone rat model of Parkinson's disease: Dose exploration study.

Subcutaneous administration of rotenone has recently attracted attention because of its convenience, simplicity and efficacy in replicating features of Parkinson's disease (PD) in animal models. However, the wide range of doses reported in the literature makes it difficult to evaluate the effectiveness of this technique objectively. The aim of the present study was to identify the optimum dose of subcutaneous rotenone for establishing a model of PD. We injected male Wistar rats subcutaneously with one of three doses of rotenone (1.5, 2, or 2.5mg/kg) daily for 5 weeks. Rotenone caused a dose-dependent increase in α-synuclein in the substantia nigra. Furthermore, at 2 and 2.5mg/kg, rotenone caused a significant decrease in the number of tyrosine hydroxylase-immunoreactive neurons in the substantia nigra, and dopamine in the striatum. However, mortality at 2.5mg/kg was 46.7%, compared with just 6.7% at 2mg/kg; the high mortality observed at 2.5mg/kg would limit its application. The 2mg/kg dose showed no detrimental effect on body weight after 5 weeks of daily injections. Furthermore, rats in the 2mg/kg group showed a longer latency to descend from a horizontal bar and a grid wall, decreased rearing, and shorter latency to fall from a rotarod than rats that received vehicle or saline. Mitochondrial damage, observed by transmission electron microscopy, was also evident at this dose. Together, our data indicate that daily subcutaneous injection of 2mg/kg rotenone in rats facilitates the formation of α-synuclein and reproduces the typical features of PD, while maintaining low mortality.

Association of TGFBR2 rs6785358 Polymorphism with Increased Risk of Congenital Ventricular Septal Defect in a Chinese Population.

Transforming growth factor beta receptor 2 (TGFBR2) plays a central role in normal heart development, and we investigated whether TGFBR2 polymorphism confers the risk of congenital ventricular septal defect (CVSD). The case-control study included 115 CVSD children and 188 healthy children in a Chinese population. TGFBR2 rs6785358 polymorphism was genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Enzyme-linked immunoassay (ELISA) was used to detect serum TGFBR2 levels. The genotype and allele frequency of TGFBR2 rs6785358 were significantly higher in the CVSD group than in the controls (all P < 0.05). The G allele carriers were associated with increased CVSD risk compared with the A allele carriers in CVSD group (OR 3.503, 95 % CI 2.670-4.596). Stratified analysis by gender revealed that the TGFBR2 rs6785358 genotype and allele frequency were significantly different between the CVSD case and controls, in both the male subgroup and the female subgroup (all P < 0.001). The G allele carriers were more susceptible to CVSD risk than the A allele carriers in both the male subgroup (OR 9.096, 95 % CI 5.398-15.33) and the female subgroup (OR 3.148, 95 % CI 1.764-5.618). Logistic regression analysis revealed that age, gender and genotype were associated with the risk of CVSD (all P < 0.05). The study findings revealed that TGFBR2 rs6785358 polymorphism contributes to CVSD susceptibility, and the G allele may increase the risk of CVSD.

[Adverse effect of environmental endocrine disruptors on gonadal development of prepubertal male rats and therapeutic effect of bushen tianjing recipe on it].

OBJECTIVE: To verify the antagonistic effect of Bushen Tianjing Recipe (BTR) on environmental endocrine disruptors (EEDs) induced gonadal dysgenesis (GD) Sprague-Dawley (SD) male rat model. METHODS: Totally 70 3-week-old male SD rats were randomly divided into seven groups, i.e., the control group (fed with corn oil), the model A group [di-2-ethylhexyl-phthalate (DEHP) 500 mg/kg], the CM A group (fed with DEHP 500 mg/kg + BTR 40 mL/kg), the exposed group B (fed with CYP 80 mg/kg), the CM B group (fed with CYP 80 mg/kg + BTR 40 mL/kg), the model C group [fed with DEHP 500 mg/kg + CYP 80 mL/kg], the CM C group (DEHP 500 mg/kg + CYP 80 mg/kg + BTR 40 mL/kg), respectively, 10 in each group. All were administered with corresponding medication by gastrogavage, once daily, for total 30 days. Rats were killed 24 h after the last administration, and their body weight and wet testis weight were weighed. The coefficient of testis was calculated. The serum testosterone (T) level was measured by chemiluminescent immunoassay. The histopathologic tissue was prepared. The ultrastructural changes of genital cells were observed by electron microscope. RESULTS: Compared with the control group, there was no statistical difference in the body weight increase among all groups (P > 0.05). The time of testicular descent and preputial separation were significantly delayed in each exposed group (P < 0.01). In the exposed group A and the exposed group C, the wet weight of the testes was reduced and serum T level decreased (P < 0.01). The coefficient of testis significantly decreased in the exposed group A (P < 0.01). Compared with corresponding model group, the time of testicular descent and preputial separation were significantly fore-laid in each corresponding CM group (P < 0.01). The weight of the testes, the coefficient of testis, and the serum T level increased in the CM A group (P < 0.01). The serum T level obviously increased in the CM B group (P < 0.05). CONCLUSIONS: The GD rat model was successfully duplicated by using DEHP. EEDs were proved to have significant anti-androgen activities. BTR was verified to have significant antagonistic to its anti-androgen effect.