Long-term exercise training inhibits inflammation by suppressing hippocampal NLRP3 in APP/PS1 mice.

Behavioral experiments have demonstrated that long-term physical exercise can be beneficial for learning and memory dysfunction caused by neuroinflammation in Alzheimer's disease (AD). However, the molecular mechanism remains poorly understood due to a lack of sufficient pertinent biochemical evidence. We investigated the potential effect of long-term physical exercise on cognition and hippocampal gene and protein expression changes in a transgenic AD mouse model. Following twenty weeks of treadmill exercise, transgenic AD mice showed improvement in cognitive functions and downregulation of Nod-like receptor protein 3 (NLRP3) (p â€‹< â€‹0.01), interleukin-1beta (IL-1ß) (p â€‹< â€‹0.05), and amyloid-ß1-42 (Aß1-42) (p â€‹< â€‹0.05) expression levels. In addition, we observed significant reductions of microglial activation and hippocampal neuronal damage in the exercised AD mice (p â€‹< â€‹0.01), which might be a result of the downregulation of NLRP3-mediated signaling and neuro-inflammatory responses. As neuronal damage due to inflammation might be a likely cause of AD-associated cognitive dysfunction. Our results suggested that the anti-inflammatory effects of exercise training involved downregulating the expression of key inflammatory factors and might play an important role in protecting hippocampal neurons against damage during the course of AD.

Rh(iii)-Catalyzed ortho-C-H alkynylation of N-phenoxyacetamides with hypervalent iodine-alkyne reagents at room temperature.

A Rh(iii)-catalyzed C-H alkynylation of substituted N-phenoxyacetamides has been developed with the aid of hypervalent iodine-alkyne reagents. Complementary to the Sonogashira coupling reaction, this protocol provides an efficient and straightforward method to access aryl alkynes at room temperature. The multifunctional directing group is preserved which can be further employed for ortho-directed functionalizations to obtain additional new complex products.

Codon usage biases in Alzheimer's disease and other neurodegenerative diseases.

Establishing codon usage biases are crucial for understanding the etiology of central nervous system neurodegenerative diseases (CNSNDD) especially Alzheimer's disease (AD) as well as genetic factors. G and C ending codons are strongly biased in the coding sequences of these proteins as a result of genomic GC composition constraints. On the other hand, codons that identified as translationally optimal in the major trend all end in C or G, suggesting translational selection should also be taken into consideration additional to compositional constraints. Furthermore, this investigation reveals that three common codons, CGC (Arg), AGC (Ser), and GGC (Gly), are also critical in affecting codon usage bias. They not only can offer an insight into the codon usage bias of AD and its mechanism, but also may help in the possible cures for these diseases.

Molecular dynamics of some pentapeptides having a strong tendency to helical conformation.

Some pentapeptides with higher alpha-helical tendency possess typical sequence pattern, such as "+ - + + - - +", "+ - - + - - +", "+ - + - - - +", and " - + + - - - +" ( "+" = D,N,E,Q,K,R,T,C, or H; "-" = L,I,V, or A), especially symmetrical motifs (a pair of reverse sequences beside palindromic segments), such as ALALA, QQAQE/EQAQQ, and REALE/ELAER, hint that the nascent peptide can fold a certain conformation in a two-way folding fashion.

Construction of drug screening cell model and application to new compounds inhibiting FITC-fibrinogen binding to CHO cells expressing human alphaIIbbeta3.

To identify potential candidates for antiplatelet drugs, human alphaIIbbeta3 (GPIIb/IIIa) was expressed in Chinese hamster ovary (CHO) cells, which was validated by tetrapeptide RGDS (Arg-Gly-Asp-Ser) with IC(50) of 0.057 mM, supported by Basani's results [Basani, R. B., French, D. L., Vilaire, G., Brown, D. L., Chen, F., Coller, B. S., Derrick, J. M., Gartner, T. K., Bennett, J. S., Poncz, M., 2000. A naturally occurring mutation near the amino terminus of alpha IIb defines a new region involved in ligand binding to alpha IIbbeta 3. Blood 95, 180-188]. The ability of 2-(4-substituted-piperazin-1-ylacetyl)-1,2,3,4-tetrahydroisoquinoline derivatives to inhibit fibrinogen binding to alphaIIbbeta3 based on the CHO cell model was measured by flow cytometry using GPIIb/IIIa assay, and the IC(50) values of compounds 1-6 were 0.166, 0.037, 0.311, 0.025, 0.034, and 0.184 mM, respectively. Our research results indicated that the compounds with phenylsulfonyl (compounds 1 and 2) and benzoyl groups (compounds 4 and 5) at position 4 of piperazine showed higher IC(50) values of inhibiting ADP-induced human platelet aggregation. Particularly compound 4 possessed IC(50) value of approximately 6.84 nM. Additionally, a complex model of alphaIIbbeta3 with compound 4 revealed that the pharmacophore of compound 4, including m-nitro group of 4-benzene-piperazine, the nitrogen atom in the piperazine group, and 2-nitrogen of 1,2,3,4-tetrahydroisoquinoline nucleus, interacted with the hydroxyl groups of Thr125 of beta3 and Tyr166 of alpha2b by hydrogen bonds and the carboxyl group at side chain of Asp179 of alpha2b in the fashion of electrostatic interaction. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays showed that compounds 4 and 5 possess potential anti-cancer activities, suggesting a potential role of integrin-guided signal pathway in cancer therapy. Further evaluation is under investigation.

Transgene expression of human PON1 Q in mice protected the liver against CCl4-induced injury.

BACKGROUND: Oxidative stress, often in association with decreased antioxidant defenses, plays a pathogenetic role in both initiation and progression of liver injuries, leading to almost all clinical and experimental conditions of chronic liver diseases. Human paraoxonase 1 (hPON1) is a liver-synthesized enzyme possessing antioxidant properties. Here, we investigate the effects of transgene-expressed hPON1 Q on alleviating lipid peroxidation and preventing liver injury in a mouse model. METHODS: The hPON1 Q gene was cloned into pcDNA3.0 plasmid and electro-transferred into mouse skeletal muscle. After CCl4 had been administrated to induce liver injury, mice were monitored for serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malonyldialdehyde (MDA). The extent of CCl4-induced liver injury was also analyzed through histopathological observations. RESULTS: After gene delivery, hPON1 mRNA expression was detected in mouse muscle and serum PON1 activity was 1.5 times higher than that of the control counterpart. In the PON1 Q gene transferred mice, protection against CCl4-induced liver injury was reflected by significantly decreased serum ALT, AST and MDA levels compared to those in control mice (P < 0.01). Histological observations also revealed that hepatocyte necrosis, hemorrhage, vacuolar change and hydropic degeneration were apparent in control mice after CCl4 administration. In contrast, the damage was significantly prevented (P < 0.01) in the hPON1 Q transferred mice. CONCLUSIONS: Intramuscular electro-transfer of the hPON1 Q gene led to efficient expression of hPON1 in mice. Elevated levels of PON1, by virtue of its potency to alleviate oxidative stress, could protect mice from suffering CCl4-induced liver damage.