Forward genetic screening of a novel gene hmgs-1 Involved in Alzheimer Disease Pathogenesis in a transgenic Caenorhabditis elegans model

A Rapid and Sensitive UHPLC-MS/MS Method for Determination of Chlorogenic Acid and Its Application to Distribution and Neuroprotection in Rat Brain

Chlorogenic acid (5-CQA) is a phenolic natural product that has been reported to improve neurobehavioral disorders and brain injury. However, its pharmacokinetics and distribution in the rat brain remain unclear. In this study, we established a rapid and sensitive UHPLC-MS/MS method for the determination of 5-CQA in rat plasma, cerebrospinal fluid (CSF), and brain tissue to investigate whether it could pass through the blood-brain barrier (BBB) and its distribution in the rat brain, and a Caenorhabditis elegans (C. elegans) strain paralysis assay was used to investigate the neuroprotective effect of 5-CQA in different brain tissues. Chromatographic separation of 5-CQA and glycyrrhetinic acid (GA, used as internal standard) was completed in 0.5 min, and the full run time was maintained at 4.0 min. Methodological validation results presented a high accuracy (95.69-106.81%) and precision (RSD ≤ 8%), with a lower limit of quantification of 1.0 ng/mL. Pharmacokinetic results revealed that 5-CQA can pass through the BBB into the CSF, but the permeability of BBB to 5-CQA (ratio of mean AUC0-∞ of CSF to plasma) was only approximately 0.29%. In addition, 5-CQA can penetrate into the rat brain extensively and is distributed with different intensities in different nuclei. A C. elegans strain paralysis assay indicated that the neuroprotective effect of 5-CQA is positively correlated with its content in different brain tissues. In conclusion, our study for the first time explored the BBB pass rate and brain tissue distribution of 5-CQA administered via the tail vein by the UHPLC-MS/MS method and investigated the potential main target area of 5-CQA for neuroprotection, which could provide a certain basis for the treatment of nervous system-related diseases of 5-CQA.

Modeling Alzheimer's Disease in Caenorhabditis elegans

Alzheimer’s disease (AD) is the most frequent cause of dementia. After decades of research, we know the importance of the accumulation of protein aggregates such as β-amyloid peptide and phosphorylated tau. We also know that mutations in certain proteins generate early-onset Alzheimer’s disease (EOAD), and many other genes modulate the disease in its sporadic form. However, the precise molecular mechanisms underlying AD pathology are still unclear. Because of ethical limitations, we need to use animal models to investigate these processes. The nematode Caenorhabditis elegans has received considerable attention in the last 25 years, since the first AD models overexpressing Aβ peptide were described. We review here the main results obtained using this model to study AD. We include works studying the basic molecular mechanisms of the disease, as well as those searching for new therapeutic targets. Although this model also has important limitations, the ability of this nematode to generate knock-out or overexpression models of any gene, single or combined, and to carry out toxicity, recovery or survival studies in short timeframes with many individuals and at low cost is difficult to overcome. We can predict that its use as a model for various diseases will certainly continue to increase.