Cholesterol is a major component of the cell membranes of brain cells. About a quarter of the total cholesterol in the human body is located in the various cells of the brain.

British scientists have studied the mechanism of aggregation of beta-amyloids in the presence of different cholesterol levels in the test tube. For their investigations, 1,2-dimyristoyl-sn-glycero-3-phosphorylcholines (DMPC) vesicles were used with or without cholesterol filling in different concentrations. (The embedding of a lipophilic substance such as cholesterol in the double layer of amembran has an influence on its bending stiffness and packing density). The vesicles were combined with Aβ 42 monomers, which had been expressed before in E.coli bacteria.

The researchers observed that the amyloids attached themselves to groups of cholesterol molecules and were therefore able to came in contact with neighbouring amyloids so that they could connect with each other. The cholesterol therefore had an effect depending on its concentration. With sufficiently high cholesterol content of the vesicle membranes, the accumulation of beta-amyloids accelerated by a factor of 20, the researchers calculated.

Only recently, American researchers had found a connection between fat molecules in the cell wall and the formation of Lewy's bodies during the development of the Parkinson's disease.

The scientists have published their observations in the journal Nature Chemistry:
Johnny Habchi, Sean Chia, Céline Galvagnion, Thomas C. T. Michaels, Mathias M. J. Bellaiche, Francesco Simone Ruggeri, Michele Sanguanini, Ilaria Idini, Janet R. Kumita, Emma Sparr, Sara Linse, Christopher M. Dobson, Tuomas P. J. Knowles & Michele Vendruscolo (2018). Cholesterol catalyses Aβ aggregation through a heterogeneous nucleation pathway in the presence of lipid membranes. Nature Chemistry, DOI: 10.1038/s41557-018-0031-x

Further information:
https://www.wissenschaft-aktuell.de/artikel/Cholesterin_im_Hirn_beschleunigt_Plaquebildung_bei_Alzheimer1771015590566.html
https://www.ch.cam.ac.uk/person/mv245
http://www.invitrojobs.com/