Mitochondria and Vitamin ET: ergothioneine

Ergothioneine is all the rage currently and for good reason. Hailed as a new vitamin by non-other than anti-aging guru Bruce Ames and the subject of many papers in Nature. Ergothioneine is rapidly being monetised as production of synthetic supplies are patented and ramped up.

The fuss is, as expected, around the dementia epidemic fears especially as ergothioneine has shown neuro-protective effects. The molecule itself shows antioxidant properties and is able to scavenge hydroxyl radicals and mitigate the oxidative actions of superoxide and hydrogen peroxide.

So far so straight forward, another anti-oxidant ... and they always get a bit of good press. What is different about ET ( as we will now call it) is that a) animals and most plants cannot make it, and b) ET is actively transported into cells and organelles by a dedicated energy driven transporter ETT. The latter is always a sign that something is important.

ET is also actively conserved, that is to say it stays around for a long time in the cells and is barely excreted, another sign of being important. This is just as well as we must get ET from our diet but within our dietary choices ET is very unevenly distributed. Mushrooms (especially boletes) are the richest source followed by red and black beans. Carnivores have fewer problems as liver and kidney are rich in ET.

This article is, as is customary for me, a mitochondrial perspective on the subject.

It will come as no surprise to find that the ETT (the transporter) is at its highest concentration in the mitochondrion. In the same vein the greatest collateral damage from mitochondrial activity comes from superoxide radicals and hydrogen peroxide, against both which ET is effective. It looks, as it always does, that as oxidative demands increase in animal tissues ( eg brain, kidney, liver) so does the need for more mitochondria and thus so does the need to mitigate the damage caused. 

Again so far so straight forward but what strikes me as a bit weird is the role of fungi in the diet. 

Fungi provide ergosterol which is cholestero-genic ( ie we easily converted it to cholesterol), Vitamin D ( if exposed to sunlight) and now ‘Vitamin’ ET, all of which are highly prized and conserved features of the mitochondrion which has dedicated receptors for D and ET and relies on constant cholesterol levels for correct membrane-di-electric properties. In other words pretty vital all round.

Were fungi once symbionts? In any case, if the world is to move towards veganism, non animal  dietary supplies of cholesterol ( from fungi and olive oil) and vitamins D and ET will be critical for mitochondrial health. I would love to see data for vegans without access to beans, fungi and olive oil.
It shouldn’t work out for them. On the other hand the above list looks just like a typical vegan diet.

Mitochondria, oscillators and broadcasters?

Is the mitochondrion the beating heart of the cell? Is it the rythm maker for biological clocks?

I have long regarded the mitochondrion as an electrical device and this topic has been covered several times in previous blogs. Recently I built a physical electronic analogue of the mitochondrion and details of this follow in the appendix to this article.

What I found to my surprise as a biochemist, but not to the surprise of any electronic engineer, that I had built a simple oscillator. The oscillation period was remarkably constant with varying capacitance and collapsed catastrophically when the leak current was too great to charge the capacitor or when the electrical energy input was too low. For interest I outputted the charging and discharging of the capacitors through the signal software called SonicPy. I could now listen to the heartbeat of my model.

To cut a long story short and confine the details to the appendix, it was clear that my model had a lot in common with how real aging mitochondrial behave but new to me was that if the capacitance model is correct then the mitochondrion is a natural oscillator. In electronics an oscillator is constructed by pairing a capacitor with an inductor. This is basically what is described below in the electronic analogue.

Mitochondrial oscillations are extensive, well documented and always involve energy dependent ion transfers.1,2, They  have variable periods from 10 to 100s of cycles per second(Hz). ‘New Agers’ in particular love the 10Hz periods as it maps to the resting Alpha waves of the brain. By the by, my toy model often settled at a similar frequency.

If however you have come across notions that bacteria and by inference mitochondria emit radio signals ( very likely given this model)  and are worried about 5G the Ghz frequencies causing interference it would be possible to imagine resonance but not with the cycling frequencies described above!

It  follows indeed, in general, that an oscillation electrical device will interact with external oscillators such as electromagnetic waves and it is inevitable that resonance energy transfer will play a part at some frequencies.

To summarise, researchers are fascinated by the oscillations in cells and bacteria that they have found. They even speculate about the fabulous internal clock and broadcasting microbes . I would subscribe to both theories but here I am proposing that the drum-beaters in eukaryotes  are the mitochondrion and that it is an inevitable result of of their simple electronics.











Appendix

A model of the mitochondrion as capacitor and oscillator

The mitochondrion is well understood to be an electrochemical structure but increasingly I think I regard it as an electrical device made from biological molecules. Mostly for fun I have created a simple electrical analogue, a picture of which is shown below.


I am able to vary energy input, membrane electrical capacitance and trans-membrane leak of charge. Or rather, I can vary electrical analogues of these well known parameters. The set up is explained below.



 


Fig 1 Breakout  boards attached to RaspberryPi





Fig 2 Sketch of Fig

How the circuit works:

A light dependent resistor (LDR) receives light from light emitting diode (LED). The intensity of light is controlled manually by moving green lever (30 degrees varied light from max to zero).

5V DC is supplied from Raspberry Pi. GPIO1 pin goes high when capacitor(s) reach approx 75% charge and is then read by Pi. The greater the supply of energy to the capacitors( in this setup this equals a lower  LDR’s resistance) the quicker the capacitor is charged. In other words the more light that falls on LDR the quicker the capacitor(s) charges.

So in analogy, the mitochondrion’s membrane potential is represented by the capacitance and the ability to charge the mitochondrion from electrons received from substrates is represented by the light intensity.

The total capacitance has two values ( 1 and 2 uF ) a variation from LOW to HIGH is achieved by the Raspberry PI controlled transistor switch (GPIO2).

In analogy, low capacitance represents mitochondria with  low internal surface area and vice-versa those with high surface areas. The former would be megamitochondria found in aged cells and the latter the sum of many smaller mitochondria.  (or complex reticulate mitochondria in younger cells).

A variable resistor connected to ground is adjusted manually which acts as a ‘bleed’ and inhibits the charging of the capacitors. As the leak increases the time taken to charge the mitochondrion increases very slightly until it fails catastrophically.

This resistor is meant to be analogous  to membrane leaks which are known to increase with age. Ultimately depolarization leads to the cascade of events that ends in apoptosis.

Finally, an air-core solenoid takes the capacitors to ground.

The mitochondrial respiratory chain is aggregated into super-structures called ‘respirasomes’ which have a distinctly spiral conformation. I am assuming the even with electron tunnelling the path followed by electrons will be a spiral thus creating the effect associated with electrical solenoids, that is storage of energy and opposition to current change.

I could ‘listen’ to the capacitors charging and discharging by outputting to sound software called SonicPy whilst manually varying the light intensity and current leak.







1.`Adv Exp Med Biol. 2008; 641: 98–117.
PMCID: PMC2692514
NIHMSID: NIHMS111938
PMID: 18783175 Mitochondrial Oscillations in Physiology and Pathophysiology
Miguel A. Aon, Sonia Cortassa, and Brian O’Rourke*

2. Effects of nanosecond pulsed electromagnetic field on mitochondrial membrane potential∗Wenjun Xu ; Xueling Yao ; Jingliang Chen.  IEEE Xplore

Steviols aging and mitochondria

As the cold weather approached I fancied buying some baked beans to have with a hot breakfast. In the past I had bought the ‘reduced salt and sugar’ version from a well known brand of baked beans. Now I find this product is replaced with a ‘no added sugar’ product.

Suspicious as usual, after reading the label I found that it contains the now ubiquitous steviol sweeteners. Now I admit that I am instinctively suspicious of anything that is basically a ragwort-extract but was not really that bothered until a) it was declared ‘safe’ by the food industry, b) a side effect of its consumption were ‘muscle pain’  and c) it now seems to be in every low sugar ( but still sweet) product.

Having had the ‘shades of statins’ bogey re-awakened I did a bit of digging looking for steviols’ effects on mitochondria. Yep, back in 1985 there was clear evidence that the family of stevia glycosides were  powerful mitochondrial inhibitors. inducing membrane depolarisation.  A few years later I noticed they were being touted as potential chemotherapy compounds for osteo-sarcoma on the grounds of their mitochondrial-mediated apoptotic properties. 

You get it, these compounds have profound effect on mitochondria. Basically that effect is to uncouple/depolarise mitochondria. This may be safe in healthy adults who need to lose a bit of weight but it will be a different story with older folk. Expect to see even more sarcopenia and mental deterioration in this group.

I can see it now, the rise and rise of the living dead. Pharma ‘solutions’ to high blood pressure, high cholesterol and obesity will produce a generation of undead morons. I truly cannot even bring myself to research this topic further; it took me minutes to find the academic papers so presumably this is all well known and will be documented with raging-hindsight in 20 yrs time. 

Mortality figures are not the issue in 21st century UK, morbidity is.

Mitochondria diabetes and cancer

Mitochondria diabetes and cancer

or 'cancerous cell love sugar, what better recommendation can you have?'

How and why do ‘normal’ somatic cells go rogue and become cancers? So much is known of the ‘how’ and in such mind-boggling detail one would have thought that some ‘motive’ would have been uncovered by now.

Of course I don’t really mean to imply  higher levels of heretical motivation to single cells going about their daily tasks as part of a multicellular collective,  or do I?  No-one after all would be embarrassed to speculate as to why say an amoeba did something or another. They might say “ this behaviour is an adaptive response to a chemical diffusing in its environment’ as it duly swims away exhibiting what they would term negative-chemotaxis.

Cells in a multicellular organism could equally  do what they will but they normally don’t. They don’t because:

a) They are physically prevented from moving being as they are part of tissues like liver, muscle kidney and so on.

b)They have stopped dividing, these  are called post-mitotic cells and form the bulk of a multicellular creature’s body like our own.

Cancers rarely form  from cells in these situations, however cells near the outer boundaries of tissues or which form part of the circulating cells ( in blood or lymph) are much more likely to rebel ... being both able to divide and even move. So most cancers are from dividing tissues ( skins or epithelia as called eg: the skin lining the outer shell, the gut, mouth, gullet, womb, cervix, lung, breast ) and mobile tissues ( blood cancers , testicular, ovarian).

More rarely, much more rarely, cells deep within tissues rebel; the common cancers above are called carcinomas the latter sarcomas. Whatever, it looks like opportunity is as always an important factor in transgression from virtue to rogue. Sticking with this the theme of opportunity. What metabolic cue can provide even more opportunity?  I think the answer is sugar. Here’s why.

It is well known that the eukaryote cell is a chimera, albeit an ancient and well integrated one between an anaerobic host and the aerobic symbiont the bacteria-like  mitochondrion.
Biochemically the putative host’s  metabolism is  sugar processing  and the mitochondrion is able to take the host’s sugar waste products as well as their own normal fatty foods and fully oxidise them liberating a lot of energy, enough indeed to build a big complex multicellular creature like us. This is the orthodoxy of student biochemistry, glycolysis followed by oxidative phosphorylation.

Mitochondria are the accidental ‘guests’ that make the miracle of the modern cell.
But, at the end of the day, bacterial-like invasion of a cell,  no matter how ‘beneficial’, is an invasion to be fought … given the opportunity. It is well documented that cancer cells suppress mitochondria, preventing them from dividing and respiring. Sugar metabolism is enough for cancers to get by and divide, albeit normally very slowly. But why suppress mitochondria? Surely more energy is a bonus if you want to grow quickly? The obvious answer is that this is personal. They want mitochondria gone.

It is now also becoming well known that Type 2 diabetes is strongly associated with cancer.
Unsurprisingly,  diabetic and more significantly perhaps pre-diabetic  conditions are associated with elevated blood glucose levels. Technically I mean elevated fasting glucose levels, that is higher than normal blood sugar when not actually eating sugar. This in my opinion is nothing less than adding another opportunity for a cell ‘wanting’ to return to its origins.

To add motivation to opportunity, how would one eject invaders from your cell? There is no real way to do this directly … but, if you divide repeatedly, and have already prevented the 'invader' from reproducing, then some cells will become free from the infection ...  applying the simple maths of dilution.

In short, cancer could be a defence albeit atavistic in the extreme to the invasion of the host cell by mitochondria. This reaction is effectively and normally comprehensively suppressed in a  multicellular organism and any opportunistic rogue cells  are ruthlessly destroyed by the marauding defensive immune-police.

But what about tipping the balance? Rapidly dividing cells in a sugary environment might just have enough opportunities lined up for one or two to be successful rogue 'start-ups'.

If then time reduces  immune surveillance through old age or stress  then  the ancient 'saccharophile' gts its chance to fight back.

UK Computer Science ... starting over?

This week the British Computer Society (BCS) writing from Roehampton University in South West London came very close to admitting that the introduction of Computer Science into English schools at GCSE and A level has been a bit of a disaster, cock up even.

A few years ago I was blogging for ComputerWorldUK and was one of the fiercest critics of the subject then called ICT and its apologist BECTA a government quango which effectively oversaw the digital revolution in schools at that time.

Long story short, BECTA was abolished, ICT given the chop ( last exams this year 2018 I believe) and Computing re-introduced ostensibly to re-create our pre-eminence in computing following a serious mocking of the current state of the nation by the then head of Google no less.

So enthused was I that I came out of teacher-retirement to teach the new GCSE and A levels in Computer Science. Maybe though I missed some early warning signs. At a educational show I was browsing a stall where the BCS was showcasing a child friendly drag and drop programming interface called Scratch. They ( the stall holders) were an odd bunch, very male very unfriendly and immune to dialogue ( ok criticism)  or interest from a veteran MIndStorms block code user.

In other words very much what you might expect from a certain CompSci stereotype.

Anyway, what transpired was eye-opening

Firstly, CompSci at GCSE and A level is hard. I have taught Chemistry, Physics, Biology, ICT and Computing (c1998) at A level, GCSE and O level during my 38 years in the business. I and my students over the years would vote for Chemistry as the hardest; Physics as impossible without good maths; Biology “easiest but lots of it”; ICT as deeply trivial but useful in the workplace ( MS Office era) and 1990s Computing really quite easy. It’s a long list but it has been a long time albeit punctuated by 10yr back in industry post 2000.

But CompSci 2016--  trumps the lot, and the reason that CompSci is so hard?  … the level of abstraction is very high.

This is a problem. Abstraction is expected to be part of the skill set of A level students but in all honesty some subjects have very little ( Biology and Geography spring to mind). CompSci has a lot. Consequently, only those students who can do this will pass in the subject let alone thrive.
Boys and girls are equally represented with regard to the ability to move from concrete to abstract work. So, from a subset of the school population ( the abstracters) will come the successful CompSci kids.

Boys though are over-represented in their love of computer hardware, computer games, and nefarious activities thus labelling the subject of CompSci as ‘male’. Many of the less successful CompSci students take the subject because of these drivers.

Now we have a double whammy, nay a treble whammy. A hard, ‘boys’ subject suitable for only those few with the best abstract handling abilities that does not deliver the League Table’s best grades. The BCS/Roehampton report here says just that in its very good summary paragraphs at beginning of the report. Worth a read.

Finally another whammy, this time it’s fatal.  Poor uptake of the subject especially at A level means that it is too expensive to keep on a schools portfolio of offerings. Few schools can continue to subsidise a subject in the time of budget squeeze.

What’s to be done? Do we really want computer and programming skills in our upcoming generations?

Easy, drop Computer Science from GCSE and GCE. It belongs with the technical qualifications.
With technical qualifications the abstract can be balanced with meaningful applied skills, (something not achievable in traditional schools). More girls will be attracted just for the reason that an employable skill is an employable skill and they are as pragmatic as boys. Place this subject in large institutions ( 1000+) so that class sizes can be viable.

In conclusion, the re-introduction of Computing to schools has been botched  by geeks who thought everyone was like them. By the way developing ‘Scratch’ was not a solution to accessing programming. It was a distracting dead end.

Mitochondrial morphology: aging and capacitance 2

Mitochondrial morphology is critical to understanding how energy demands are managed by cells. The key to understanding how this is regulated lays in an electrochemical capacitance model. 

In a 2016 article from the Salk Institute, the importance of mitochondrial morphology was presented in its clearest form1. Essentially the team shows that mitochondria respond withregard to their size and shape, to  AMPK* enzymes. These are in effect part of a signalling system that monitors cellular ATP levels.

A drop in ATP levels ( in response to exertion-demand or toxins/poisons ) causes the mitochondria population to shatter in as much as they don’t burst but divide into a collection of a much smaller spheroid population. This is in contrast to some of the large, sometimes exotic, reticulate and tubular confections that mitochondria can form.

Mitochondrial fusion and fission was the subject of the conjectures in the paper and such musings have been mine for many years. In my PhD thesis and observed many times subsequently sged, senescent cells often show ‘mega-mitochondria’ with spherical shape and few cristae. I have speculated on the meaning of this change at length in a previous blog2.

My conclusions were that this was a phenomenon driven by electrical capacitance and the maintenance of a critical threshold membrane potential.

The question then, in light of the research and evidence of a variation in morphology from Salk, is what is the significance of such an astonishing range of shape and size?

My thesis has always been that it concerns the  electronic capacitance of a mitochondrion.
The free energy needed to drive the synthesis of ATP occurs at membrane potentials of 120+ mv. A mitochondrion with a large surface area, ie one with a great deal of inner membrane folding, must of course, meet the 120mv condition but will, by virtue of its larger internal surface area, have a greater capacitance.

This means, as in regular electronics, that it can store more energy than its counterparts with smaller capacitances. It is ‘easier’ to fully charge ( ie reach the critical threshold potential to produce ATP) an individual  mitochondrion with a smaller capacitance than one with the higher values simply because it requires less charge. However TOTAL CAPACITANCE within a cell will the sum of the individual capacitances of the mitochondria.

 It is also clear from ageing studies and the work illustrated by Salk that mitochondrial morphology (and hence capacitance) appears highly adaptive  …  but why?

In a very energetic high output cells ( say a bird or bat’s muscle cells ) you find many many very small tightly coupled ( ie low charge-leaking) mitochondria. In failing, senescent cells you see a few large swollen mitochondria with very little internal folding. In dividing cells, you can see an amazing network, a reticulum of fused and branching mitochondria wrapped around the nucleus undergoing division.

I think there are enough clues here to speculate on the role of mitochondrial morphology.
If I stick to the capacitance-charge model then it is possible to outline different scenarios.

Scenario 1: Small, high cristae level spheroids. 

Each mitochondrion has a relatively small capacitance so will reach the ‘ATP charge level’ quickly. A population of small spheroids has a much larger external surface area, as delineated by the outer membrane, than do the equivalent super-reticulate structures. This ratio aids rapid transport of charge (supplied by food) to the mitochondrion. So although in time of high demand, individual mitochondria could discharge below their threshold easily, they can also  be re-supplied very quickly.

This is consistent with finding of lots of small mitos as a result of high energy demands or even poisoning where resultant charge leakage across the membrane can be accommodated by ( using electronics analogy) drawing more current. High collective capacitance, high external surface area to maximise 'food' supply.


Scenario 2: Large reticulated structures.

A super-net of mitochondria, fully charged, stores a lot of energy within the inner-membrane folds but presents a relatively low external surface area in contrast with the spheroid extreme describe above.

In the extreme case of a dividing cell, the opportunity to ‘feed’ the mito-structures is lower than normal as the cell itself is otherwise engaged. However the free energy to power cell division (which requires a predictable and a modest amount of ATP) can be stored in the ‘giant capacitor’ that surrounds the nucleus. High capacitance and relatively low external surface.


Between the two extremes above must lay ‘normal’, ‘poisoned and senescent scenarios.

I would guess that in stable low ATP demand tissues mitochondrial fusion would be favoured, as if ‘stockpiling’ energy if the demand suddenly arose or if feeding was suspended for a while.. On the other hand in very high output tissues then small low capacitance mitochondria would favour fission.

In poisoned or senescent scenarios, charge-leakage across the inner mitochondrial membrane would demand an adaptive change to reduce capacitance. There are two ways of achieving this: small mitochondria with normal cristae or large mitochondria with fewer cristae.

My conjecture is that in a low-economy cell for example, a semi-senescent cell (in limbo like an underused muscle cell, parked and marked for death), a large medium capacity mitochondrion is superior to many smaller versions (with overall similar total capacity) because the risk of local depolarisation is reduced. That is, one small mitochondrion, although requiring less to charge it, a demand ( an energy draw) is much more likely to cause it to depolarise if it is already is leaking. This is critical because depolarisation could trigger the cascade leading to apoptosis.

The larger single mitochondrion is less likely to simply locally fail. It still might fail but not as in the case above have inevitable mini- failures. It is a case of all eggs in fewer baskets.

The Ageing Mitochondria Scenario

With age mitochondria lose the ability to divide (or fuse) and they leak more charge. This means that to meet the energy demands of a cell they cannot divide and regenerate in response to AMPK signalling even if it is still working. In order to maintain minimum capacitance to supply enough energy for the cell they need to enlarge. Hence the appearance of mega-mitochondria. After this response any failure in the supply side of 'food' or further leaking will spell the end.



*AMPK a collection of protein kinases activated by AMP (adenosine monophosphate) a marker for ATP levels ( adenosine triphosphate).




1) https://www.sciencedaily.com/releases/2016/01/160114152323.htm
2) https://www.blogger.com/blogger.g?blogID=3906287940044842441#editor/target=post;postID=5246291255183981633;onPublishedMenu=allposts;onClosedMenu=allposts;postNum=28;src=postname

Microsoft's AI for NHS?

Many years ago I would blog under the auspices of ComputerWorld.uk about UK educational computing. I was an open source apologist and enjoyed the collective outrage we felt when the money that the then UK government spent on Microsoft operating systems and Office software was made public.

Schools and public bodies were basically being ripped off as each upgrade iteration was released until suddenly all all came to a screeching halt. The school’s advisory quango BECTA was abolished and  schools stopped upgrading.

What happened was that an awful lot of public sector computers ended up still using Windows XP ( just ask the NHS ) though most schools and public sector businesses now use Win7; MS Office became relatively cheap and outsourcing giants such as Capita kept a fierce lid on spending.

Ah, those were the days.

Microsoft changed tack realising that the Cloud and Big Data would be the future but knowing that selling Office365 off their Azure cloud would not be a runner against Google’s ‘free’ doc suite. They got wise and made a  move on a new cash cow, aka medicine.

Put simply, medics collect data, always have, always will. Nowadays there are lots of data sitting in databases just waiting to be ‘mined’.  Big data mining is all the rage, sophisticated (you might suppose) algorithms honed by maths genii look for pattern and correlation in order to discover the meaning of life or whatever they are selling. Yes I am a skeptic but medics and economists love this stuff.

Some countries have diverse medical systems but one country has a monolithic, cradle to grave system. That’s BIGLY population data. So bigly that these data now form the basis of what goes for post grad research ( no more pesky experiments for the millennials ). Oh sorry forgot to mention the country …it’s the UK. And we have the NHS.

Today, Mrs May the UK Prime Minister has just announced that she will use (ie  fund) AI ( artificial intelligence) to save ‘thousands of lives’ and cure cancer by mining all that data.
She will need help to do this of course. Luckily Cara McGoogan reported in The Telegraph last September about Microsoft’s new Cambridge-based Health Care AI research unit!

Maybe I’m too skeptical, too untrusting, too suspicious: maybe the words Cambridge and data-harvesting are not the best combo at present, thanks to London based Cambridge Analytica’s Facebook misbehaviour. But I’m sure nothing will happen to the NHS’s data in Microsoft’s hands. Maybe even it’s not Microsoft being awarded this work but my gut-data says otherwise.

I just hope HM Gov got a good price or it’ll look like deja-vu all over again.

I can feel a Freedom of Info request coming on.