WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome, 2023 Hwang et al

Last note from Dr. Hwang

"My lab is focused on continuing our experiments to get additional insights into WASF3 while also trying to translate concurrently these insights into the clinics. I believe it is important to proceed carefully and do the best job possible at each stage, especially because I know how important the stakes are here. We have what we need to do our work at this time, but if and when additional needs arise, you can be sure that I will make requests to the appropriate sources."
 
Was just curious, did anyone catch Dr. Hwang's talk in Berlin, online anywhere?

'The World Mitochondria Society will host Targeting Mitochondria 2023 with challenging visions in Berlin'

Date: October 11-13

Highlighted WMS Speakers 2023: Paul Hwang, National Heart, Lung and Blood Institute, USA'

"Dr. Hwang's talk will be titled: "WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in ME/CFS".

"He will share his latest findings reported in the Proceedings of the National Academy of Sciences. Increased expression of WASF3 in transgenic mice decreased their treadmill running capacity and specific respiratory complexes. Expanding on our findings in a single patient, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels associated with aberrant ER stress activation. Pharmacologic inhibition of ER stress decreased WASF3 and improved mitochondrial function in the cells of the patient with chronic fatigue, suggesting a therapeutic strategy for ME/CFS treatment."
 
I'm thinking to myself - what study was that? And here's the kicker - this is the reference:
Chaudhuri and Behan "In vivo magnetic resonance spectroscopy in chronic fatigue syndrome" 2004.
The 2004 study is a review of several small studies done in the 1990s. I wonder if the technique is still relevant today and if it would be worth repeating it today with a larger sample size. I would suggest an exercise test that is more focussed on muscle endurance rather than a short burst of intense exercise (like CPET).
 
Thanks for sharing @Dolphin and lovely that medicalnewsbulletin covered this.

The article opens with
Recently we highlighted a new study that may answer the question “how come people with ME/CFS have totally normal looking muscle cells suffer from post exertional malaise?”

Is that really the case? Has anybody looked at muscle cells in particular in relation to post exertional malaise? From what I can tell Rob Wüsts exploratory, not yet published data, would show the opposite and I'm not aware of other muscle biopsy studies related to PEM.
 
Thanks for sharing @Dolphin and lovely that medicalnewsbulletin covered this.

The article opens with


Is that really the case? Has anybody looked at muscle cells in particular in relation to post exertional malaise? From what I can tell Rob Wüsts exploratory, not yet published data, would show the opposite and I'm not aware of other muscle biopsy studies related to PEM.
I know Dr Charles Shepherd had a muscle biopsy done, i think in the 90s, that was abnormal in some way, but i dont remember the details.
 
My understanding is that the link to mitochondria is autophagy (degradation of damaged cellular components) and maybe also organization of the mitochondrial network. It also has various other roles.

But this is a complicated topic and I may be misunderstanding. I'll have to read more. It's possible that the NIH knows something that we don't.

PS:

On further reading, a picture emerges of WAVE3 being part of one of several protein complexes that physically attach mitochondria to the endoplasmatic reticulum. This would also allow mitochondria and the ER to communicate with each other. This has been studied in cancer.

This is interesting to me as I carry Pompe's disease (one allele, insufficient GAA enzyme) but should be without overt symptoms. This is a lysosomal condition with, in overt Pompe's, poor breakdown of glycogen in lysosome and compromised autophagy. In carriers glycogen breakdown should remain adequate but no one knows about degree of impairment of autophagy. I also have sarcoidosis which ties in as poor autophagy can leave "irritating" residues which may fire the immune system and conversely sarcoid may inhibit autophagy, which in my case may already be compromised.
How this might tie into 35+ years of fatigue and post exertional worsening is hard to say as my sarcoid diagnosis is from 2023 thoug my Mum had acute sarcoid in 68-72 ish and has parallel symptoms to my own, largely speaking.
There may be overlaps, study of which may render insights into each condition.
 
Email from Paul Hwang to me regarding Relyvrio.


“Thank you for your interest.
We are not committed to any specific drug, and we are still in the midst of our preclinical experiments.

Please know that we will only follow molecular mechanism based data for ME/CFS, not ALS, that passes scientific review.”
 
When I want to feel hopeful I re-read this paper. The irony is that while Wallitt was wasting $8million on his silly preconceived notion, on the other side of the NIH Hwang was doing this work with cancer funding. And I'm increasingly hopeful he has cracked it wide open. To me this puzzle piece fits better than any other.

He finds that some aspects of the unfolded protein response are in action, but it's not working like the textbooks say (there are 3 arms to the UPR, Hwang finds one of them is running hot, PERK, but not activating the downstream thing it should be activating (called EIf2a).)

If that is right, then the unfolded protein response (UPR) could be central to PEM - the triggers and timing are right. UPR can be started by exercise and - this was the aha! moment for me - it is one of a few mechanisms in the body that runs on a delay.

After trying to solve the protein folding problem for a number of hours, the unfolded protein response causes cells to destroy themselves via apoptosis and/or necroptosis. The timing could match PEM. You exercise, you feel kind of okay for a bit, then at a certain point afterwards the body decides to blow up a million muscle cells at about the same time and you are flooded with damage signals, making the whole body freak out: brain, endothelium, immune, energy, everything.

In our case it seems the standard UPR is not exactly what's happening, it depends on EIF2a and leads to apoptosis. But when apoptosis is compromised, ER stress can leads to necrosis:

Death sentence: The tale of a fallen endoplasmic reticulum (2021)

3.2.2. ER stress-induced necroptosis (Fig. 2)

Necroptosis, or regulated necrosis, is a form of cell death induced by diverse stimuli and involves signaling molecule RIPK3, and its effector MLKL, which forms pores in the plasma membrane [26]. Necroptosis is thought to be engaged as a back-up when apoptosis is compromised, and switches between these modes of cell death upon TNF-signaling are dependent on the PTM of TNFR1-associated complex components, in particular regulation of RIPK1 which activates RIPK3 [33]. Mouse fibroblast L929sA cells die via necroptosis upon treatment with TNF, and chemical ER stressors. Suppression of RIPK1, RIPK3, or MLKL in these cells is sufficient to switch the mode of ER stress-induced cell death from necroptosis to apoptosis; and JNK signaling enhances both cell death modalities. Though L929sA cells could be considered atypical in their response to ER stress, this study indicates that the UPR may induce necroptosis in particular circumstances through a hitherto undescribed mechanism [34]. Indeed, necroptotic machinery can interact with ER stress sensors (Section 3.3) and chemical chaperones which reduce ER stress can prevent necroptosis [35,36], but little or no mechanistic link has been reported between the UPR sensors and execution of necroptosis. For example, CHOP induction by small molecule LGH00168 was reported to induce necroptosis in the human lung cancer cell line A549, but via Reactive Oxygen Species (ROS) production and not via CHOP-driven expression of necroptosis machinery [37]. One confounding study initially reported two PERK inhibitors as preventing RIPK1-mediated necroptosis however, it was subsequently found that these compounds also inhibited RIPK1, and that PERK was not involved in the necroptotic phenotype [38]. This lack of precise molecular links could suggest that the effect of ER stress on necroptosis may in fact be independent of the UPR, and come as a result of other physiological effects of ER stress.


Whether or not it involves the canonical parts of the UPR, everyone agrees unresolved ER stress causes cell death after a delay. I think there's a strong chance we will find the basis of PEM here, and a theoretical basis for pacing - keep your ER stress below the necroptotic threshold.

I'd love to trawl the microRNA and extracellular vesicle data we have for any signs of these necroptotic pathways being activated.
 
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There's also this "anticipatory" UPR pathway, which is not very well described in the literature yet but affected by estrogen, which is relevant to our purposes here. It seems to depend on cells leaking ATP, which leads me to wonder if Naviaux's long-lingering suramin idea could be useful if this mechanism is indeed in play...

Strong and sustained activation of the anticipatory unfolded protein response induces necrotic cell death
Mara Livezey 1 , Rui Huang 1 , Paul J Hergenrother 1 2 , David J Shapiro 3
Affiliations
Abstract
The endoplasmic reticulum stress sensor, the unfolded protein response (UPR), regulates intracellular protein homeostasis. While transient activation of the reactive UPR by unfolded protein is protective, prolonged and sustained activation of the reactive UPR triggers CHOP-mediated apoptosis. In the recently characterized, evolutionarily conserved anticipatory UPR, mitogenic hormones and other effectors pre-activate the UPR; how strong and sustained activation of the anticipatory UPR induces cell death was unknown. To characterize this cell death pathway, we used BHPI, a small molecule that activates the anticipatory UPR through estrogen receptor α (ERα) and induces death of ERα+ cancer cells. We show that sustained activation of the anticipatory UPR by BHPI kills cells by inducing depletion of intracellular ATP, resulting in classical necrosis phenotypes, including plasma membrane disruption and leakage of intracellular contents. Unlike reactive UPR activation, BHPI-induced hyperactivation of the anticipatory UPR does not induce apoptosis or sustained autophagy. BHPI does not induce CHOP protein or PARP cleavage, and two pan-caspase inhibitors, or Bcl2 overexpression, have no effect on BHPI-induced cell death. Moreover, BHPI does not increase expression of autophagy markers, or work through recently identified programmed-necrosis pathways, such as necroptosis. Opening of endoplasmic reticulum IP3R calcium channels stimulates cell swelling, cPLA2 activation, and arachidonic acid release. Notably, cPLA2 activation requires ATP depletion. Importantly, blocking rapid cell swelling or production of arachidonic acid does not prevent necrotic cell death. Rapid cell death is upstream of PERK activation and protein synthesis inhibition, and results from strong and sustained activation of early steps in the anticipatory UPR. Supporting a central role for ATP depletion, reversing ATP depletion blocks rapid cell death, and the onset of necrotic cell death is correlated with ATP depletion. Necrotic cell death initiated by strong and sustained activation of the anticipatory UPR is a newly discovered role of the UPR.
 
There's also this "anticipatory" UPR pathway, which is not very well described in the literature yet but affected by estrogen, which is relevant to our purposes here. It seems to depend on cells leaking ATP, which leads me to wonder if Naviaux's long-lingering suramin idea could be useful if this mechanism is indeed in play...

Strong and sustained activation of the anticipatory unfolded protein response induces necrotic cell death
Mara Livezey 1 , Rui Huang 1 , Paul J Hergenrother 1 2 , David J Shapiro 3
Affiliations
Abstract
The endoplasmic reticulum stress sensor, the unfolded protein response (UPR), regulates intracellular protein homeostasis. While transient activation of the reactive UPR by unfolded protein is protective, prolonged and sustained activation of the reactive UPR triggers CHOP-mediated apoptosis. In the recently characterized, evolutionarily conserved anticipatory UPR, mitogenic hormones and other effectors pre-activate the UPR; how strong and sustained activation of the anticipatory UPR induces cell death was unknown. To characterize this cell death pathway, we used BHPI, a small molecule that activates the anticipatory UPR through estrogen receptor α (ERα) and induces death of ERα+ cancer cells. We show that sustained activation of the anticipatory UPR by BHPI kills cells by inducing depletion of intracellular ATP, resulting in classical necrosis phenotypes, including plasma membrane disruption and leakage of intracellular contents. Unlike reactive UPR activation, BHPI-induced hyperactivation of the anticipatory UPR does not induce apoptosis or sustained autophagy. BHPI does not induce CHOP protein or PARP cleavage, and two pan-caspase inhibitors, or Bcl2 overexpression, have no effect on BHPI-induced cell death. Moreover, BHPI does not increase expression of autophagy markers, or work through recently identified programmed-necrosis pathways, such as necroptosis. Opening of endoplasmic reticulum IP3R calcium channels stimulates cell swelling, cPLA2 activation, and arachidonic acid release. Notably, cPLA2 activation requires ATP depletion. Importantly, blocking rapid cell swelling or production of arachidonic acid does not prevent necrotic cell death. Rapid cell death is upstream of PERK activation and protein synthesis inhibition, and results from strong and sustained activation of early steps in the anticipatory UPR. Supporting a central role for ATP depletion, reversing ATP depletion blocks rapid cell death, and the onset of necrotic cell death is correlated with ATP depletion. Necrotic cell death initiated by strong and sustained activation of the anticipatory UPR is a newly discovered role of the UPR.
Interesting .
We had the mitochondrial test from Myhill within first year or so . It did look at a lot of things ,and hasn't been replicated by others .
It did look at ATP. My daughter was chucking it out cells at a high rate . At the time I didn't realise it was also a signalling molecule.
 
I'm not aware of other muscle biopsy studies related to PEM.
yes pretty sure it was done by Peter Behan. Or at least with his involvement.

The Behans have done muscle biopsies in ME/CFS patients in the past (I believe this was more Wilhelmina's project than Peter's), although, while done on patients in which PEM was acknowledged, they were afaik not specifically done after inducing PEM.

Some snippets from Behan et al. 1985 (there are several other things investgated in this study):
"Muscle biopsies were abnormal in all 20 patients examined by this technique. In 15, single, widely scattered, necrotic muscle fibres were identified but there was no inflammatory infiltrate associated with the necrosis. Histochemical stains showed moderately increased size and numbers of Type II fibres in all. By electron microscopy, mitochondria were conspicuously increased at the periphery of the fibres and occasional tubular inclusions were present. Routine electrophysiological testing was normal, but 30 of the 40 patients showed conspicuously abnormal jitter, indicating subtle but definite primary muscle lesions. The topical nuclear magnetic resonance investigation revealed abnormal muscle metabolism in each of the six patients studied. This varied in degree from mild to severe. There was abnormally early intracellular acidosis during exercise. This finding was interpreted as being consistent with increased lactic acid formation and denoting a disorder of metabolic regulation in the muscle."
.....
The histological changes of scattered muscle fibre necrosis, while subtle, were definite, being found in 75% of the biopsies while there was predominance of Type II fibres in all. Bizarre tubular structures and increased peripheral mitochondria were detected by electron microscopy. Similar tubular structures, shown to be derived from sarcoplasmic reticulum, have recently been demonstrated in cases of severe myalgia. That muscle appeared to bear the brunt of the disease is also confirmed by the findings of conspicuously increased jitter on single-fibre EMG, and by the metabolic changes noted during NMR studies."

And
"We found no abnormal clinical signs in our 50 patients. If they were exercised, however, they did exhibit gross weakness."

In 1994 Wilhelmina Behan reported:
"... that electron microscopy has shown abnormalities of mitochondria: enlargement, change of shape and proliferation of cristae, giving an abnormal honeycomb appearance, was found in up to 70% of muscle biopsies (the abnormal mitochondria were about twice the size of normal). The structure of mitochondria is very closely linked to energy metabolism and Dr Behan concluded that the findings suggest an interference with energy metabolism. Cell cultures were established from 10 muscle biopsies and severe decrease in cell respiration was found in two of the four samples tested. Serum acylcarnitine is deficient in CFS patients. A mtDNA deletion was found in four patients but in none of the controls. These data on mitochondria suggest that CFS may be precipitated by environmental factors in individuals who are genetically predisposed."
At the same symposium a researcher from Italy (Dr E. Pizzigallo) reported that he and his team
"...carried out muscle biopsies from the vastus lateralis muscle in (ME)CFS patients and found alterations in the tissue “compatible with a myopathy of probable mitochondrial origin”, which might account for the decreased functional capacity of muscles in (ME)CFS patients."
(Margaret Williams, 2011)
 
When I want to feel hopeful I re-read this paper. The irony is that while Wallitt was wasting $8million on his silly preconceived notion, on the other side of the NIH Hwang was doing this work with cancer funding. And I'm increasingly hopeful he has cracked it wide open. To me this puzzle piece fits better than any other.

He finds that some aspects of the unfolded protein response are in action, but it's not working like the textbooks say (there are 3 arms to the UPR, Hwang finds one of them is running hot, PERK, but not activating the downstream thing it should be activating (called EIf2a).)

If that is right, then the unfolded protein response (UPR) could be central to PEM - the triggers and timing are right. UPR can be started by exercise and - this was the aha! moment for me - it is one of a few mechanisms in the body that runs on a delay.

After trying to solve the protein folding problem for a number of hours, the unfolded protein response causes cells to destroy themselves via apoptosis and/or necroptosis. The timing could match PEM. You exercise, you feel kind of okay for a bit, then at a certain point afterwards the body decides to blow up a million muscle cells at about the same time and you are flooded with damage signals, making the whole body freak out: brain, endothelium, immune, energy, everything.

In our case it seems the standard UPR is not exactly what's happening, it depends on EIF2a and leads to apoptosis. But when apoptosis is compromised, ER stress can leads to necrosis:

Death sentence: The tale of a fallen endoplasmic reticulum (2021)

3.2.2. ER stress-induced necroptosis (Fig. 2)

Necroptosis, or regulated necrosis, is a form of cell death induced by diverse stimuli and involves signaling molecule RIPK3, and its effector MLKL, which forms pores in the plasma membrane [26]. Necroptosis is thought to be engaged as a back-up when apoptosis is compromised, and switches between these modes of cell death upon TNF-signaling are dependent on the PTM of TNFR1-associated complex components, in particular regulation of RIPK1 which activates RIPK3 [33]. Mouse fibroblast L929sA cells die via necroptosis upon treatment with TNF, and chemical ER stressors. Suppression of RIPK1, RIPK3, or MLKL in these cells is sufficient to switch the mode of ER stress-induced cell death from necroptosis to apoptosis; and JNK signaling enhances both cell death modalities. Though L929sA cells could be considered atypical in their response to ER stress, this study indicates that the UPR may induce necroptosis in particular circumstances through a hitherto undescribed mechanism [34]. Indeed, necroptotic machinery can interact with ER stress sensors (Section 3.3) and chemical chaperones which reduce ER stress can prevent necroptosis [35,36], but little or no mechanistic link has been reported between the UPR sensors and execution of necroptosis. For example, CHOP induction by small molecule LGH00168 was reported to induce necroptosis in the human lung cancer cell line A549, but via Reactive Oxygen Species (ROS) production and not via CHOP-driven expression of necroptosis machinery [37]. One confounding study initially reported two PERK inhibitors as preventing RIPK1-mediated necroptosis however, it was subsequently found that these compounds also inhibited RIPK1, and that PERK was not involved in the necroptotic phenotype [38]. This lack of precise molecular links could suggest that the effect of ER stress on necroptosis may in fact be independent of the UPR, and come as a result of other physiological effects of ER stress.


Whether or not it involves the canonical parts of the UPR, everyone agrees unresolved ER stress causes cell death after a delay. I think there's a strong chance we will find the basis of PEM here, and a theoretical basis for pacing - keep your ER stress below the necroptotic threshold.

I'd love to trawl the microRNA and extracellular vesicle data we have for any signs of these necroptotic pathways being activated.

I think this might track with some of the slides Rob Wüst showed on Dutch TV after exercise. I thought a lot of the muscle cells pooped out after exercise as opposed to healthy controls. Would have to rewatch it though, and read this more clearly. Which I'm not up to atm.
 
I think this might track with some of the slides Rob Wüst showed on Dutch TV after exercise. I thought a lot of the muscle cells pooped out after exercise as opposed to healthy controls. Would have to rewatch it though, and read this more clearly. Which I'm not up to atm.
Yep, Rob Wust found necrosis in muscle cells after exercise (pictured below, panel B).

A possible explanation is acute endoplasmic reticulum stress that led to an unfolded protein response which didn't resolve the problem and caused necrosis instead.

Screenshot 2024-03-20 at 8.57.14 am.png
 
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