Phosphatidylcholine-Plasmalogen-Oleic Acid Reduces BACE1 Expression in Human SH-SY5Y Cells.

Plasmalogens are a family of glycerophospholipids containing one vinyl-ether bond at the sn-1 position in the glycerol backbone, and play important roles in cellular homeostasis including neural transmission. Therefore, reductions of plasmalogens have been associated with neurodegenerative disorders, such as Alzheimer's disease (AD). To evaluate the potential protective effects of plasmalogens against the pathology of AD, protein expression levels of key factors in amyloid precursor protein (APP) metabolic processes were examined using human neuroblastoma SH-SY5Y cells. Here, phosphatidylcholine-plasmalogen-oleic acid (PC-PLS-18) was shown to reduce protein expression levels of ß-site APP cleaving enzyme 1 (BACE1), clusterin, and Tau, factors involved in the amyloid ß-associated pathogenesis of AD. Thus, PC-PLS-18 may have preventive effects against AD by delaying the onset risk for a certain period.

Protective effect of Lactococcus laudensis and Pediococcus parvulus against neuropathy due to amyloid-beta in Caenorhabditis elegans.

In Alzheimer's disease (AD), the amyloid-ß (Aß) protein begins to accumulate in the brain 20 years prior to any dementia symptoms manifestation, in which Aß aggregates in the brain, causing destruction of nerve cells and resulting in memory impairments. Lifestyle and diet appear to inhibit Aß production and amyloid deposition. Therefore, identifying factors that prevent Aß production and administering them before the onset of AD, may be an effective preventive method. Lactic acid bacteria (LAB) exhibit various health effects on the host and are expected to have protective effects on neurological functions via brain-gut correlation. However, the protective effects of LAB against Aß are not well understood. We investigated whether LAB feeding could ameliorate the toxicity of Aß peptide accumulation in transgenic Caenorhabditis elegans expressing the human Aß peptide in neurons or muscle as an AD model. Aß expressed in muscle caused myopathy and worm paralysis, while Aß in neurons disturbed chemotactic activity. Among 14 screened strains, Lactococcus laudensis (LL) and Pediococcus parvulus (PP) prevented the AD worms from losing their chemotaxis behavior and becoming paralyzed by the Aß peptide. Immunostaining and western blotting indicated that Aß peptide was significantly suppressed in worms fed these two strains, and binding of the Aß to vitellogenin was particularly inhibited. Conversely, the mRNA level of the Aß gene did not change between LL- or PP-fed worms and the control. In conclusion, LL and PP alleviate neurotoxicity by inhibiting Aß accumulation; AD model worms can be used to screen efficient LAB for AD prevention.

Phosphatidylcholine-Plasmalogen-Oleic Acid Has Protective Effects against Arachidonic Acid-Induced Cytotoxicity.

Plasmalogens are a group of glycerophospholipids containing a vinyl-ether bond at the sn-1 position in the glycerol backbone. Cellular membrane plasmalogens are considered to have important roles in homeostasis as endogenous antioxidants, differentiation, and intracellular signal transduction pathways including neural transmission. Therefore, reduced levels of plasmalogens have been suggested to be associated with neurodegenerative diseases such as Alzheimer's disease. Interestingly, although arachidonic acid is considered to be involved in learning and memory, it could be liberated and excessively activate neuronal activity to the excitotoxic levels seen in Alzheimer's disease patients. Here, we examined the protective effects of several kinds of plasmalogens against cellular toxicity caused by arachidonic acid in human neuroblastoma SH-SY5Y cells. As a result, only phosphatidylcholine-plasmalogen-oleic acid (PC-PLS-18) showed protective effects against arachidonic acid-induced cytotoxicity based on the results of lactate dehydrogenase release and ATP depletion assays, as well as cellular morphological changes in SH-SY5Y cells. These results indicate that PC-PLS-18 protects against arachidonic acid-induced cytotoxicity, possibly via improving the stability of the cellular membrane in SH-SY5Y cells.

Oral ingestion of plasmalogens can attenuate the LPS-induced memory loss and microglial activation.

Plasmalogens (Pls) are the special phospholipids which were reported to be reduced in brain and blood samples of Alzheimer's disease (AD) patients, suggested a possibility that an oral ingestion of Pls may prevent the disease progression. Interestingly, the clinical study showed that the daily oral ingestion of Pls among the mild AD patients improved cognition. However, it is unknown of whether the oral ingestion of Pls inhibits the AD like changes in brain e.g., glial activation and accumulation of amyloid beta (Aß) proteins. To elucidate the beneficial effects of the Pls oral ingestion, we have used the chronic lipopolysaccharide (LPS) injection model mice where the glial activation and Aß accumulation were well reported. In the present study, we have found that the Pls drinking at the doses of 0.1 µg/ml and 10 µg/ml for 3 months attenuated the glial activation and accumulation of amyloid beta (Aß) proteins in the murine brain. Interestingly, the LPS injection reduced the hippocampal dependent memory in the control mice but the groups of Pls drinking mice showed a better performance in the memory test, suggesting that oral intake of Pls can inhibit LPS-mediated memory loss associated with a reduction of glial activation and Aß accumulation in the brain. We, therefore, suggest that the oral ingestion of Pls among the AD patients may also inhibit the glial activation resulting in the improvement of cognition.

Detection of ruminant meat and bone meal in feeds by sandwich ELISA with monoclonal antibodies.

A sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) using two monoclonal antibodies directed against a synthetic peptide with an amino-acid sequence related to the C-terminus of bovine myoglobin and the whole molecule of sodium dodecyl sulphate (SDS)-denatured bovine myoglobin was adapted for detecting bovine myoglobin in contaminated feeds. The ELISA employed bovine meat extract of a known myoglobin concentration as a calibration standard and had an limit of detection (LOD) of 3.54 ng/ml and an limit of quantification (LOQ) of 11.0 ng/ml corresponding to 0.022% and 0.067% (wt/wt) bovine meat-and-bone-meal (MBM) mixed in 20-fold-diluted feed extracts, respectively. A cut-off threshold of 20.6 ng/ml bovine myoglobin was set to simplify ELISA and facilitate quick assessment of test results without a tedious calibration process. The ELISA was able to detect bovine MBM in artificially prepared model feeds, mixed botanical feeds, mixed botanical feeds with skimmed milk, fish meal, pork meal and pork/chicken meal at 0.1% (wt/wt). It was also able to detect sheep MBM in test feeds, but showed no reactivity to swine MBM, chicken MBM, skimmed milk or gelatine of bovine origin. The advantages of this method are the quick and easy extraction protocol of proteins from test feeds, using 100 mM sodium sulphide and 0.6% sodium dodecyl sulphate in the extraction solution and the effective detection of bovine and sheep MBM at 0.1% (wt/wt).

Quantification of pork, chicken and beef by using a novel reference molecule.

A standard plasmid was constructed as a novel reference molecule for use in real-time quantitative PCR assays to verify the identity of beef, pork, chicken, mutton, and horseflesh. The plasmid contained a target domain of the cytochrome b (cyt b) gene and an artificial DNA sequence. Primers CO-F and CO-R, and probe CO-P were specifically designed to detect the artificial sequence. The calculated R² values of the standard curves (10³-107 copies per reaction) for the five species ranged between 0.998 and 0.999 in the quantification analysis. The constructed plasmid provides a universal method for measuring the copy number of cyt b DNA in minced meat. This method would be a useful procedure for verifying food labels.

Spoilage ability of psychrotrophic Paenibacillus spp. isolated from cooked food products.

Five spore-forming bacterial strains were isolated as the most dominant microorganisms from five products of different types of cooked food. Three strains in particular were isolated as spoilage organisms causing acidity. These belonged to the genus Paenibacillus, and one of them was identified as Paenibacillus odorifer. All five strains grew at 10 degrees C in brain heart infusion broth; furthermore, four strains grew at 4 degrees C also. These strains grew optimally at 30 to 35 degrees C. Psychrotrophic Paenibacillus spp. can easily be mistaken for lactic acid bacteria in routine analysis because of their colony characteristics. Because the measures that must be taken for bacterial control are different in the case of contamination by these two bacterial groups, psychrotrophic Paenibacillus spp. contamination must be distinguished from that caused by lactic acid bacteria.

Paenibacillus macerans possesses two types of 16S rDNA copies in a genome with a length difference of twelve base pairs.

Two Paenibacillus macerans strains, JCM 2500T and MCRI 12, exhibited two types of 16S rDNA copies in their genomes, accompanied by a length difference of 12 bp at positions 203 to 214 (Escherichia coli numbering). The long-type sequences were newly identified for P. macerans 16S rDNA, and the copy numbers were different between the two strains. Both types of 16S rRNA were expressed in each strain, and it was predicted that the polymorphism at this position is located in helix H10, based on a comparison with the E. coli 16S rRNA secondary structure model.