Deletion of Dcf1 Reduces Amyloid-ß Aggregation and Mitigates Memory Deficits.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease. One of the pathologies of AD is the accumulation of amyloid-ß (Aß) to form senile plaques, leading to a decline in cognitive ability and a lack of learning and memory. However, the cause leading to Aß aggregation is not well understood. Dendritic cell factor 1 (Dcf1) shows a high expression in the entorhinal cortex neurons and neurofibrillary tangles in AD patients. OBJECTIVE: Our goal is to investigate the effect of Dcf1 on Aß aggregation and memory deficits in AD development. METHODS: The mouse and Drosophila AD model were used to test the expression and aggregation of Aß, senile plaque formation, and pathological changes in cognitive behavior during dcf1 knockout and expression. We finally explored possible drug target effects through intracerebroventricular delivery of Dcf1 antibodies. RESULTS: Deletion of Dcf1 resulted in decreased Aß42 level and deposition, and rescued AMPA Receptor (GluA2) levels in the hippocampus of APP-PS1-AD mice. In Aß42 AD Drosophila, the expression of Dcf1 in Aß42 AD flies aggravated the formation and accumulation of senile plaques, significantly reduced its climbing ability and learning-memory. Data analysis from all 20 donors with and without AD patients aged between 80 and 90 indicated a high-level expression of Dcf1 in the temporal neocortex. Dcf1 contributed to Aß aggregation by UV spectroscopy assay. Intracerebroventricular delivery of Dcf1 antibodies in the hippocampus reduced the area of senile plaques and reversed learning and memory deficits in APP-PS1-AD mice. CONCLUSION: Dcf1 causes Aß-plaque accumulation, inhibiting dcf1 expression could potentially offer therapeutic avenues.

Thamnolia vermicularis extract improves learning ability in APP/PS1 transgenic mice by ameliorating both Aß and Tau pathologies.

Considering the complicated pathogenesis of Alzheimer's disease (AD), multi-targets have become a focus in the discovery of drugs for treatment of this disease. In the current work, we established a multi-target strategy for discovering active reagents capable of suppressing both Aß level and Tau hyperphosphorylation from natural products, and found that the ethanol extract of Thamnolia vermicularis (THA) was able to improve learning ability in APP/PS1 transgenic mice by inhibiting both Aß levels and Tau hyperphosphorylation. SH-SY5Y and CHO-APP/BACE1 cells and primary astrocytes were used in cell-based assays. APP/PS1 transgenic mice [B6C3-Tg(APPswe, PS1dE9)] were administered THA (300 mg·kg-1·d-1, ig) for 100 d. After the administration was completed, the learning ability of the mice was detected using a Morris water maze (MWM) assay; immunofluorescence staining, Congo red staining and Thioflavine S staining were used to detect the senile plaques in the brains of the mice. ELISA was used to evaluate Aß and sAPPß contents, and Western blotting and RT-PCR were used to investigate the relevant signaling pathway regulation in response to THA treatment. In SH-SY5Y cells, THΑ (1, 10, 20 µg/mL) significantly stimulated PI3K/AKT/mTOR and AMPK/raptor/mTOR signaling-mediated autophagy in the promotion of Aß clearance as both a PI3K inhibitor and an AMPK indirect activator, and restrained Aß production as a suppressor against PERK/eIF2α-mediated BACE1 expression. Additionally, THA functioned as a GSK3ß inhibitor with an IC50 of 1.32±0.85 µg/mL, repressing Tau hyperphosphorylation. Similar effects on Aß accumulation and Tau hyperphosphorylation were observed in APP/PS1 transgenic mice treated with THA. Furthermore, administration of THA effectively improved the learning ability of APP/PS1 transgenic mice, and markedly reduced the number of senile plaques in their hippocampus and cortex. The results highlight the potential of the natural product THA for the treatment of AD.

PSCL: predicting protein subcellular localization based on optimal functional domains.

It is well known that protein subcellular localizations are closely related to their functions. Although many computational methods and tools are available from Internet, it is still necessary to develop new algorithms in this filed to gain a better understanding of the complex mechanism of plant subcellular localization. Here, we provide a new web server named PSCL for plant protein subcellular localization prediction by employing optimized functional domains. After feature optimization, 848 optimal functional domains from InterPro were obtained to represent each protein. By calculating the distances to each of the seven categories, PSCL showing the possibilities of a protein located into each of those categories in ascending order. Toward our dataset, PSCL achieved a first-order predicted accuracy of 75.7% by jackknife test. Gene Ontology enrichment analysis showing that catalytic activity, cellular process and metabolic process are strongly correlated with the localization of plant proteins. Finally, PSCL, a Linux Operate System based web interface for the predictor was designed and is accessible for public use at http://pscl.biosino.org/.

AICAR induces astroglial differentiation of neural stem cells via activating the JAK/STAT3 pathway independently of AMP-activated protein kinase.

Neural stem cell differentiation and the determination of lineage decision between neuronal and glial fates have important implications in the study of developmental, pathological, and regenerative processes. Although small molecule chemicals with the ability to control neural stem cell fate are considered extremely useful tools in this field, few were reported. AICAR is an adenosine analog and extensively used to activate AMP-activated protein kinase (AMPK), a metabolic "fuel gauge" of the biological system. In the present study, we found an unrecognized astrogliogenic activity of AICAR on not only immortalized neural stem cell line C17.2 (C17.2-NSC), but also primary neural stem cells (NSCs) derived from post-natal (P0) rat hippocampus (P0-NSC) and embryonic day 14 (E14) rat embryonic cortex (E14-NSC). However, another AMPK activator, Metformin, did not alter either the C17.2-NSC or E14-NSC undifferentiated state although both Metformin and AICAR can activate the AMPK pathway in NSC. Furthermore, overexpression of dominant-negative mutants of AMPK in C17.2-NSC was unable to block the gliogenic effects of AICAR. We also found AICAR could activate the Janus kinase (JAK) STAT3 pathway in both C17.2-NSC and E14-NSC but Metformin fails. JAK inhibitor I abolished the gliogenic effects of AICAR. Taken together, these results suggest that the astroglial differentiation effect of AICAR on neural stem cells was acting independently of AMPK and that the JAK-STAT3 pathway is essential for the gliogenic effect of AICAR.

[Effect of musk soluble components on the growth, the differentiation and the transfection efficiency of rat neural stem cells (NSC) in vitro].

AIM: To investigate the effect of musk soluble components on the growth, the differentiation and the transfection efficiency of rat neural stem cell (NSC) in vitro. METHODS: The growth and the differentiation of rat NSC were observed when musk soluble components were added into the culture medium of NSC. Meanwhile, the pEGFP-C1, which expressed the enhanced GFP protein, was transfected into the NSC by method of electro- transfection. RESULTS: When NSC was treated with musk soluble components, the neurites were outgrowth around NSC and attached to the plate, and the neural spheres were disassociated. The glia-like cells appeared at the concentration of 0.3 per thousand. When the concentration of musk soluble components was lower than 3 per thousand, the transformative cells could recover. Furthermore, the efficiency of transfection pEGFP into NSC was remarkably increased after the treatment with musk. CONCLUSION: After the treatment of NSC with musk soluble components, the neural spheres were disassociated, and then attached to the plate. Musk soluble components could induce NSC differentiation into glia-like cells and improve the transfection efficiency of pEGFP-C1 in vitro.

[Physicochemistry and bioreactivity characterization of fine particles (PM(2.5)) in Shanghai air].

PM(2.5) was collected at Shanghai urban and suburban sites during spring and autumn. PIXE (Proton Induced X-ray Emission) was used to investigate mass concentration of 15 elements (S, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Sr, Pb) in Shanghai PM(2.5). The total mass concentration of the 15 chemical elements was higher in spring (5 038.6 ng x m(-3)) than in summer (3 810.6 ng x m(-3)). In spring, mass concentrations of these elements in urban and suburban samples were in the same level. In summer, concentration of the elements in urban samples were lower than in suburban samples, however, the elements which were originated from anthropogenic resources were in higher level in urban samples. The results of FESEM showed that Shanghai PM(2.5) was consisted of soot aggregates, coal fly ashes, minerals, bio-particles and unidentified particles. The result of Plasmid DNA assay demonstrated bioreactivity of urban PM(2.5) was more reactive than that of suburban PM(2.5), this phenomenon probably was explained by higher mass level of heavy metals and more proportion of soot aggregates in urban PM(2.5).

The rice tapetum degeneration retardation gene is required for tapetum degradation and anther development.

In flowering plants, tapetum degeneration is proposed to be triggered by a programmed cell death (PCD) process during late stages of pollen development; the PCD is thought to provide cellular contents supporting pollen wall formation and to allow the subsequent pollen release. However, the molecular basis regulating tapetum PCD in plants remains poorly understood. We report the isolation and characterization of a rice (Oryza sativa) male sterile mutant tapetum degeneration retardation (tdr), which exhibits degeneration retardation of the tapetum and middle layer as well as collapse of microspores. The TDR gene is preferentially expressed in the tapetum and encodes a putative basic helix-loop-helix protein, which is likely localized to the nucleus. More importantly, two genes, Os CP1 and Os c6, encoding a Cys protease and a protease inhibitor, respectively, were shown to be the likely direct targets of TDR through chromatin immunoprecipitation analyses and the electrophoretic mobility shift assay. These results indicate that TDR is a key component of the molecular network regulating rice tapetum development and degeneration.