Tagged: Huntingtin

“Three hellos” for Parkinson’s

Trehalose is a small molecule – nutritionally equivalent to glucose – that helps to prevent protein from aggregating (that is, clustering together in a bad way).

Parkinson’s disease is a neurodegenerative condition that is characterised by protein aggregating, or clustering together in a bad way.

Is anyone else thinking what I’m thinking?

In today’s post we will look at what trelahose is, review some of the research has been done in the context of Parkinson’s disease, and discuss how we should be thinking about assessing this molecule clinically.


Neuropathologists examining a section of brain tissue. Source: Imperial

When a neuropathologist makes an examination of the brain of a person who passed away with Parkinson’s, there are two characteristic hallmarks that they will be looking for in order to provide a definitively postmortem diagnosis of the condition:

1.  The loss of dopamine producing neurons in a region of the brain called the substantia nigra.

d1ea3d21c36935b85043b3b53f2edb1f87ab7fa6

The dark pigmented dopamine neurons in the substantia nigra are reduced in the Parkinson’s disease brain (right). Source:Memorangapp

2.  The clustering (or ‘aggregation’) of a protein called alpha synuclein. Specifically, they will be looking for dense circular aggregates of the protein within cells, which are referred to as Lewy bodies.

A Lewy body inside of a neuron. Source: Neuropathology-web

Alpha-synuclein is actually a very common protein in the brain – it makes up about 1% of the material in neurons (and understand that there are thousands of different proteins in a cell, thus 1% is a huge portion). For some reason, however, in Parkinson’s disease this protein starts to aggregate and ultimately forms into Lewy bodies:

shutterstock_227273575

A cartoon of a neuron, with the Lewy body indicated within the cell body. Source: Alzheimer’s news

In addition to Lewy bodies, the neuropathologist may also see alpha synuclein clustering in other parts of affected cells. For example, aggregated alpha synuclein can be seen in the branches of cells (these clusterings are called ‘Lewy neurites‘ – see the image below where alpha synuclein has been stained brown on a section of brain from a person with Parkinson’s disease.

Lewy_neurites_alpha_synuclein

Examples of Lewy neurites (indicated by arrows). Source: Wikimedia

Given these two distinctive features of the Parkinsonian brain (the loss of dopamine neurons and the aggregation of alpha synuclein), a great deal of research has focused on A.) neuroprotective agents to protect the remaining dopamine-producing neurons in the substantia nigra, and B.) compounds that stop the aggregation of alpha synuclein.

In today’s post, we will look at the research that has been conducted on one particular compounds that appears to stop the aggregation of alpha synuclein.

It is call Trehalose (pronounces ‘tray-hellos’).

Continue reading

Advertisements

Tetrabenazine: A strategy for Levodopa-induced dyskinesia?

Dyk

For many people diagnosed with Parkinson’s disease, one of the scariest prospects of the condition that they face is the possibility of developing dyskinesias.

Dyskinesias are involuntary movements that can develop after long term use of the primary treatment of Parkinson’s disease: Levodopa

In todays post I discuss one experimental strategy for dealing with this debilitating aspect of Parkinson’s disease.


Dysco

Dyskinesia. Source: JAMA Neurology

There is a normal course of events with Parkinson’s disease (and yes, I am grossly generalising here).

First comes the shock of the diagnosis.

This is generally followed by the roller coaster of various emotions (including disbelief, sadness, anger, denial).

Then comes the period during which one will try to familiarise oneself with the condition (reading books, searching online, joining Facebook groups), and this usually leads to awareness of some of the realities of the condition.

One of those realities (especially for people with early onset Parkinson’s disease) are dyskinesias.

What are dyskinesias?

Dyskinesias (from Greek: dys – abnormal; and kinēsis – motion, movement) are simply a category of movement disorders that are characterised by involuntary muscle movements. And they are certainly not specific to Parkinson’s disease.

As I have suggested in the summary at the top, they are associated in Parkinson’s disease with long-term use of Levodopa (also known as Sinemet or Madopar).

7001127301-6010801

Sinemet is Levodopa. Source: Drugs

Continue reading