Page 84 - AWSAR 2.0

60 || AWSAR Awarded Popular Science Stories - 2019
How a Harmonious Relationship Between the Brain and the Bone can Keep Alzheimer’s Disease at Bay?
Dr Viji Vijayan*
Email: vijivijayan@nii.ac.in
When it comes to comparing the carbohydrates and proteins on the plate, proteins are ‘heroes’. However, there are times when these ‘necessary building blocks of life’ can turn into villains as well. To name one is the ‘amyloid protein42’ in the brain.
Amyloid proteins are not only seen in vertebrates but also found in bacteria, fungi and plants where these exert many protective functions. In our brain, normal amyloid protects the brain from infection, repairs leaks in the blood to the brain barrier, regulates neuronal communication and so on. Nevertheless, these characteristics of a miraculous protein get lethal during a disease. For example, in the brain of a patient with Alzheimer’s disease, these proteins are found as ‘heaps’
of metabolic wastes biologically named as ‘amyloid plaques’. Amyloid plaques are made of amyloid-beta peptide, a chain of 37–40 amino acid residues. These are generated when a large neuronal membrane protein called ‘amyloid precursor protein (APP)’ is clipped at certain positions with specific enzymes in a distinct set of series. When the clipping position and series are altered, different sizes of amyloid-beta are generated and sent ‘outside the cell’ where they exist as monomers (1 unit), oligomers (few units) and even fibrils (countless units). These ‘avatar’ versions of amyloid-beta take a toll when there is a ‘toxic gain of function’. For example, when the gene sequence of APP is altered, amyloid-beta version of 42 amino acids (popularly known as Abeta42) is produced.
* Dr Viji Vijayan, Post Doctoral Fellow from National Institute of Immunology, Delhi, is pursuing her research on “Mechanisms by which Bone Proteins Influence Abeta42 Aggregation, Amyloid Deposition and Immune Response in Mouse Models of Alzheimer’s Disease”. Her popular science story entitled “How a Harmonious Relationship Between the Brain and the Bone can Keep Alzheimer’s Disease at Bay?” has been selected for AWSAR Award.