Can Alpha Synuclein be seen using a microscope?
 

As far as I can tell most of the alpha synuclein in the body is in the red blood cells. Does anyone know if they can be seen with a microscope or do they require an electron scanning microscope?

More than 99% of the alpha-synuclein resides in the red blood cells (RBCs) with less than 1% of the total detected in the plasma, platelets and peripheral blood mononuclear cells.
More than 99% of the alpha-synuclein in human blood is present in the peripheral blood cells, with the remainder in plasma.

Red blood cells are the major source of alpha-synuclein in blood. - ResearchGate. Available from: http://www.researchgate.net/publicat...clein_in_blood [accessed May 19, 2015].

http://www.researchgate.net/publicat...clein_in_blood

Alpha-synuclein is a small protein (140 amino acid residues, about 14.5 kDa).

That means that it is too small to be seen directly by any current microscopy method.

It is possible to visualise the regions within a cell in which it is found using a specific antibody which has been tagged with a reporter enzyme or fluorescent probe.

However, this approach ("immunocytochemistry") just reports on regions (membrane-bound, in the nucleus, etc) rather than showing individual alpha-synuclein molecules.

I wonder when the alpha synuclein gets put into the red blood cells? Perhaps in the bone marrow where red blood cells are created. It seems like if they could be somehow prevented from being formed, PD patients would have fewer symptoms and PD may even reverse! Or could a filter be made to remove the alpha synuclein from the red blood cells?

Two.companies, which we have discussed here before, are trying to do this. Affirms AG and Prothena are both researching A-Syn vaccines to attempt to reduce the levels in PD patients. They both have the goal of slowing, or halting, PD progression by reducing the amount of misfolded or mutated A-Syn. Early results have been very encouraging.

Thanks. I see they have both passed phase I/safety studies are are hoping to start phase 2 soon.

I think that you are right - the alpha-synuclein gene probably gets switched on in the bone marrow stem cells which lead to formation of red blood cells and so alpha-synuclein protein ends off inside red blood cells. What (if anything) the function of alpha-synuclein protein is in those cells seems to be unknown. I doubt that alpha-synuclein protein can "escape" from red blood cells.

However, there are a couple of papers which may provide food for thought.

One looked at red blood cells in mice which had had their alpha-synuclein gene removed ("knocked-out"). Their red blood cells were fine but they had lower levels of markers of oxidative stress than the red blood cells of mice in which the alpha-synuclein gene was present; http://www.ncbi.nlm.nih.gov/pubmed/25043722 .

The other one showed that, in the MPTP mouse model of PD, the knock-out mice had higher levels of striatal dopamine compared to mice in which the alpha-synuclein gene was present; http://www.ncbi.nlm.nih.gov/pubmed/15288507 .

Yes, safety studies were fine, well tolerated, at least short term. They also had very good biomarker results. Prothena showed mean free serum A-Syn reductions up to 96%. Of course, what we don't know at this point, is if reduced free serum levels will actually slow or halt the neuro degenerative effects of misfolded, aggregated, a-Syn. We also don't know if there will be any negative impact from removing normal a-Syn from the body. Remember, this protein is needed for normal neuron functions and is involved as a presynaptic neural transmitter.

OK, so it can't be seen with a normal microscope, but can it be "seen" in another sense. The issue is: can it be measured? And, better still, is there a DIY way of measuring it and its misfolding?

If we can't measure it directly, what proxy measures are there? For instance, aggregations of alpha-synuclein, Lewy bodies, can be seen in a microscope.

John

John, you have asked some hard questions which I will try to answer as best that I can.

The issue is: can it be measured?
Yes, alpha-synuclein levels can be measured in biological fluids (CSF, plasma, etc) - I would do this using an immunoassay. An immunoassay could also be used to measure intra-cellular alpha-synuclein levels in whatever kind of cells after those cells have been lysed, which means releasing their contents.

And, better still, is there a DIY way of measuring it and its misfolding?
The short answer to these questions is "No". Immunoassays and ways of measuring alpha-synuclein misfolding both need access to expensive instruments which are not generally available DIY.

For instance, aggregations of alpha-synuclein, Lewy bodies, can be seen in a microscope.
Lewy bodies can be seen in a microscope. However, that does not show that they contain alpha-synuclein - it needs immunocytochemistry, which I mentioned in one of my contributions above in this discussion.

I hope that you find my answers to your questions helpful.

aren't lewy bodies mostly alpha synuclein? lewy bodies are found in skin cells, i believe cheek cells and in small intestine.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699677/