Author: Adekola Taylor
In recent times, scientists have unveiled some important neurological events that could lead to Alzheimer’s disease. Alzheimer’s disease can be defined as a progressive and an age-linked neurodegenerative disease which is characterized by loss of neuronal cells in the brain and dementia (Farbood et al). Two new studies have implicated a protein that is responsible for the spreading of dementia across the brain (Arnold). The formation of these problematic proteins through the act of clumping together results in cognitive difficulty of the brain. For a long time, researchers are of the opinion that the abnormal folding of a protein called amyloid-beta protein that travels from cell to cell might cause more of these proteins to assume deformed shape. However, it has been found that the clumped proteins which are implicated in major neurodegenerative diseases and in Alzheimer’s disease have similar behaviours and patterns like that of prion, a toxic protein that is associated with destruction of brain in mad cow disease (Walker & Jucker).
Prions are durable but misshapen versions of proteins present in nerve cells which could cause similar proteins to abnormally fold and clump together. The abnormal folding and clumping together of these proteins normally lead to a toxic chain reaction that would finally consume the brain regions where the reaction is elicited. This process has been regarded by many researchers to play prominent roles, not only in mad cow disease but also in major neurodegenerative disorders such as Alzheimer’s disease, Lou Gehrig’s disease, Parkinson’s disease etc. The comprehension of these recent findings is charting a new cause and insight that could lead to the emergence of better treatment options for these aforementioned diseases. According to Walker and Jucker, recent research into various neurodegenerative diseases connotes that these neurodegenerative disorders lack the infectiousness of prion-related diseases; however, they might elicit similar damage to the brain by the process called pathogenic protein seeding. Researchers suggest that proteinaceous seeds may be released and transported by cells like that of prions, thereby spreading from one place to another.
Aging has been considered as the common cause of dementia, for instance, Alzheimer’s disease progressive deteriorate over the course of many years. It has been reported that after the age of 65 years, the incidence of Alzheimer’s doubles every five years, and one in three adults with age of 85 years must have been afflicted with the disease. Recent findings have made researchers to understand that protein clumping is involved in the emergence of neurodegenerative diseases. When these clumped proteins are magnified through electron microscope, they can be seen as long fibres made up of Aß or tau. The clumping formation of proteins into smaller assemblies known as protofibrils and oligomers would lead to disruption of the normal functioning of neurons. Researchers have discovered that the abnormal clumping of proteins takes place at very early stage in the Alzheimer’s disease process and also the sign of Alzheimer’s start to show in the brain a decade or more before the symptoms appear ( Gary).
Hope for Dementia
There have been a lot of postulations and submissions about the origin and causes of various neurodegenerative disorders. Most of these theories have not fully pinpointed explicitly and raised hope for the better treatment options through which diseases could be managed or treated. The new insight to the understanding of the pathology of these diseases is charting a new course for further research in effectively combating of the menace of neurodegenerative diseases. Managing and treating dementia-related diseases over the years has been a herculean task. Alzheimer’s disease which is commonly associated with old age has been considered by most people has a necessary evil. However, the recent findings are raising hope of tackling most of these diseases effectively.
Two Hypotheses on Dementia
The following two research hypotheses are deeply rooted in the study of dementia:
- Misfolded amyloid-beta protein (Aß) in form of small aggregates acts as a seed that initiated a toxic chain reaction of protein clumping.
- The toxic chain reaction of protein clumping devastates the brain regions in Alzheimer’s.
Many studies have confirmed that these two hypotheses as true.In a study carried out on mice, before the mice could start producing their own Aß plaques, the brains of the mice that received the Alzheimer’s brain extracts were characterized by significant aggregated Aß. Moreover, it was noticed that the extent of formation of Aß plaque was directly proportional to how long it had to incubate and to the amount of Aß in the donor brain extract. More importantly, in the transgenic mice donor brains without aggregated Aß did not seed plague formation. The experiments carried out indicated that the deposition of Aß was caused by Alzheimer’s brain extracts injected. This was confirmed after one week that the deposits were observed and it was noted that the former aggregated Aß in the brain was no-where to be found but the plaques became apparent after a wait period of a month and more (Walker & Jucker).
Another important observation that supported the two hypotheses was the stimulation of plaque formation was solely initiated by the Alzheimer’s brain extracts, that is to say, Aß not other factors such as human viruses. This observation was confirmed through the fact that the extracts from non-Alzheimer's brains, the control, did not cause the clumping of Aß (Walker & Jucker). As a matter of fact, this removed the possibility that the plaques could have been caused by brain injury that might have occurred during the process of injecting the extracts. To further ascertain whether misfolded amyloid-beta protein (Aß) acted as a seed that initiated a toxic chain reaction of protein clumping, misfolded amyloid-beta protein was selectively removed from the brain extracts using antibodies to eradicate the chances of Alzheimer's brain samples in inducing plaque formation. Furthermore, strong acid was used to unfold the misfolded proteins; this caused the brain extracts not to induce plaque formation. In other words, the misfolded proteins and the aggregation of other Aß molecules were responsible for plaque formation.
Further research is needed to investigate the characteristics of Aß seeds responsible for protein clumping in the brain and also more emphasis should be laid on the comprehensive role of seeded protein aggregation in the disease. Finally, it is crystal clear that the toxic chain reaction of protein clumping would devastate the brain regions in Parkinson’s, Alzheimer’s and other neurodegenerative diseases.
Arnold, Carrie. “Planting Seeds of Dementia : A Cascade of Misfolded Proteins may trigger Alzheimer's”. Scientific American (November 22nd, 2012). Web.7.Dec.2014.
Farbood Y., Sarkaki A. and Badavi M. “Preventive Effect of Grape Seed Hydroalcholic Extract On Dementia Type of Alzheimer’s Disease in Aged Male Rats”. (2009).International Journal of Pharmacology 5(4): 257-262. Web.7.Dec.2014.
Gary Stix . "Alzheimer's: Forestalling the Darkness". Scientific American (June 2010). Web.7.Dec.2014.
Walker Lary C. and Jucker Mathias. “Seeds of Dementia”. Scientific American (May, 2013). Web.7.Dec.2014.
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