Kan viden om hajer hjælpe med at forklare ME- og EHS-sygdomsmekanismen?

Der må findes en biologisk forklaring på, hvorfor nogle ME patienter udvikler elektromagnetisk hypersensitivitet (EHS) mod selv ekstremt lave felter. Måske kan viden om hajer hjælpe os på sporet.

Hajer er de mest "el-følsomme" dyr i verden. De kan mærke felter med så lav en værdi som 5 nV/cm. Det elektriske felt bliver opfanget af sensorer, der kaldes ampullae of Lorenzini. Hajerne anvender deres sensorer til at mærke de svage elektriske felter fra deres byttedyr. Det er observeret, at hajer kan gå til angreb på telegraf-kabler på havets bund, fordi de fejlagtigt opfattes som byttedyr (1, 2).

Ampullae of Lorenzini indeholder keratansulfat, som er en proton (H+) conductor (en elektrisk leder). Det betyder, at protonerne (H+) kan blive transporteret langs med keratansulfat molekylekæder, som er omgivet af vand (H2O). H+ vandrer langs rækken af hydrogenbindinger mellem (H2O og hydrofile enheder (se figur 1 i reference 3). Hver ampul indeholder et lag af celler, der kan opfange de elektriske signaler. Mellem cellerne er der tætte samlinger, således at der ikke kan forekomme lækstrøm mellem cellerne (2, 3).

Fig 1 from reference 3. The keratan sulfate.

(A) Chemical structure of KS. (B) An illustration of a three-monomer segment of KS. Possible intra- and inter-molecular hydrogen bonds as well as the hydrogen bonds between the water of hydration and the polar parts of the molecule form a continuous network comprised by hydrogen-bond chains. The sulfate group interacts with the hydrogen-bond network and forms an H3O+ (hydronium) ion. https://doi.org/10.1371/journal.pone.0202713.g001

Protonerne (H+) i vandige opløsninger bindes til H2O og eksisterer således som H3O+. Protonerne (H+) eksisterer kun under 1% af tiden, hvor de overføres fra et vandmolekyle til et andet. En grundig beskrivelse af fænomenet findes i DeCourseys review, reference 4.


Bemærk at artiklen om keratansultat i hajer hedder (3):
Proton conductivity of glycosaminoglycans

Glycosaminglycaner  (GAGs) er lange kæder af polysakkarider.  Der findes fem typer GAGs (5):

• heparan sulfate
• chondroitin sulphate
• dermatan sulphate
• keratan sulphate
• hyaluronic acid

Dvs der er flere typer GAGs med proton conductivity (kan lede protoner). Herudover kan også kollagen være leder for protoner (3).

Vores extracellulære matrix (ECM) er fyldt med GAGs. 

Mellem alveolar epithelium og kapillær endothelium findes et tyndt lag ECM med GAGs og kollagen (5). På jævnt dansk: I et tyndt lag mellem det fine lungevæv og de små fine blodkar findes ECM (figur 2 i reference 5).

Dette lag har stor betydning for udveksling af ilt, kuldioxid og protoner (figur 24 i reference 4, 5). Og det har betydning for immunforsvar, lungesygdomme og astma (5).

Et nærliggende spørgsmål er om det også kan have betydning for iltoptagelse ved motion? Eller betydning for multiple chemical sensitivity (MCS)?

Og kan en dysregulering af GAGs og/eller lækstrøm i utætheder forårsage EHS?


YOU TUBE:

INTERVIEW EXTRA: Ampullae of Lorenzini

https://www.youtube.com/watch?v=0QVE1dFXFRo

How Do Sharks and Rays Use Electricity to Find Hidden Prey?

https://www.youtube.com/watch?v=JDPFR6n8tAQ

Referencer:
1) Electroreception https://en.wikipedia.org/wiki/Electroreception

2) Ampullae of Lorenzini
https://en.wikipedia.org/wiki/Ampullae_of_Lorenzini


3) Selberg, Manping, Rolandi (2019): Proton conductivity of glycosaminoglycans. Plos One Published: March 8, 2019
https://doi.org/10.1371/journal.pone.0202713

4) DeCoursey TE. Voltage-gated proton channels and other proton transfer pathways (vol 83, pg 475, 2003). Physiological Reviews. 2003 Jul;83(3):1067–.
https://www.physiology.org/doi/full/10.1152/physrev.00028.2002

5) Souza-Fernandes AB1, Pelosi P, Rocco PR
Bench-to-bedside review: the role of glycosaminoglycans in respiratory disease. Crit Care. 2006;10(6):237.
https://www.ncbi.nlm.nih.gov/pubmed/17118216

.

Photoimmunology and the ME IDO metabolic trap

The sun emits ultraviolet radiation (UVR) with different wavelengths:

• UVA (320 - 400 nm)
• UVB (280 - 320 nm)
• UVC (< 280 nm)

UVR can cause sunburn and increase the risk of skin cancer. UVR is also immunomodulatory and can be beneficial in the case of inflammatory and autoimmune diseases, but UVR can also exacerbate some autoimmune diseases (1, 2).

Chromophores are the parts of a photorecpetor that absorb photons in light (1).

UVB radiation can be absorped by cytosolic tryptophan, which thus function as a chromophore. This results in the formation of tryptophan photoproducts in particular 6-formylindolo[3,2-b]carbazole (FICZ). FICZ binds to aryl hydrocarbon receptor (AhR) and activates downstream signalling pathways, which contribute to UVR-induced immunosupression (1).


Figur 1 from reference 3. Light dependent synthesis of FICZ. 6-Formylindolo[3,2-b]carbazole (FICZ) is formed by the action of light on tryptophan. FICZ activation of AhR regulates important biological pathways and increases expression of CYP1A1 as a feedback mechanism to induce its own metabolism (3).

AhR activation by FICZ reduces receptor for IgE (FcεRI) and upregulates IDO expression in Langerhans cells (4).

The IDO metabolic trap hypothesis for ME suggests that antigen-presenting cells are driven into a pathological state with increased cytosolic tryptophan. The following decrease in kynurenine products (including FICZ) may disturb the immune system homeostasis (5).

Several ME patients get better in the sun. Is it because sun-induced FICZ moderate the immune system?

References: 
1) Bernard, J.J., Gallo, R.L. & Krutmann, J. Photoimmunology: how ultraviolet radiation affects the immune system. Nat Rev Immunol 19, 688–701 (2019) doi:10.1038/s41577-019-0185-9

https://www.nature.com/articles/s41577-019-0185-9

2) Fritsche et al: Lightening up the UV response by identification of the arylhydrocarbon receptor as a cytoplasmatic target for ultraviolet B radiation. Proc Natl Acad Sci U S A. 2007 May 22;104(21):8851-6. Epub 2007 May 14. https://www.ncbi.nlm.nih.gov/pubmed/17502624

3) Zhang, C., Creech, K.L., Zuercher, W.J. et al. Gram-scale synthesis of FICZ, a photoreactive endogenous ligand of the aryl hydrocarbon receptor. Sci Rep 9, 9982 (2019) doi:10.1038/s41598-019-46374-7 
 https://www.nature.com/articles/s41598-019-46374-7

4) Koch et al: AhR mediates an anti-inflammatory feedback mechanism in human Langerhans cells involving FcεRI and IDO. Allergy. 2017 Nov;72(11):1686-1693. doi: 10.1111/all.13170. Epub 2017 May 10. https://www.ncbi.nlm.nih.gov/pubmed/28376268

5) Efimov et el. The mechanism of substrate inhibition in human indoleamine 2,3 dioxygenase. J Am Chem Soc. 2012 Feb 15;134(6):3034-41. doi: 10.1021/ja208694g. Epub 2012 Feb 2. https://www.ncbi.nlm.nih.gov/pubmed/22299628

2-OGDO enzymer og jern redox status hos ME patienter

I de foregående tre blogindlæg har jeg redegjort for, at cellers jern redox status er vigtig for aktiviteten af en række enzymer.

Enzymgruppen 2-oxoglutarate dependent dioxygenaser (2-OGDO) anvender også jern i ferro form (Fe2+) som cofactor.

Jeg vil nu stille spørgsmålet: Er 2-OGDO enzym aktiviteterne i ME celler påvirket af en forstyrret jern redox ligevægt?

2-OGDO enzymerne katalyserer en lang række biologiske processer, herunder (1):

• hydroxylering af kollagen
• demethylering af histoner
• første og sidste trin i dannelsen af carnitin
• nedbrydning af fytinsyre (eng: phytanic acid)

Aktivering af 2-OGDO enzymer starter med binding af Fe2+, hvorefter ilt (dioxygen = O2) bindes til Fe2+. Dette stimulerer den oxidative decarboxylering af 2-oxoglutarate (=alfa-ketoglutarate) til succinate og CO2, og samtidig dannes oxiderede jern mellemprodukter (Fe3+/4+). Disse højvalente jern oxidanter kan hydroxylere et molekyle, dvs sætte en OH-gruppe på molekylet (1).

Ascorbat (c-vitamin) og glutathione kan reducere Fe3+ og Fe4+ tilbage til Fe2+, således at aktiviteten af 2-OGDO enzymerne genetableres. Bemærk at genetablering af ferro-tilstanden (Fe2+) også er det centrale i de tre forrige blogindlæg.

Citat fra reference 1: "It seems that the 2-OGDO enzymes are at the nexus of independent control between energy metabolism and availability of oxygen and iron in the regulation of cellular homeostasis."

Ydermere oplyser ref 1, at transferrin og transferrin receptor er nøgle-komponenter til regulering af jern ligevægten. Disse komponenter dukkede op i et ME genomic studie:

OMICS and iron metabolism in ME
http://followmeindenmark.blogspot.com/2019/10/omics-and-iron-metabolism-in-me.html

Dannelse af carnitin og ME sygdomsmekanismen

Carnitin er nødvendig for omsætning af fedtsyrer. Carnitin fås gennem kosten, og kroppen danner også selv carnitin. Carnitinen dannes gennem flere enzymatiske trin, hvor to trin katalyseres af 2-OGDO enzymerne: trimethyllysine hydroxylase (TMLH) og gamma-butyrobetaine hydroxylase (BBOX eller GBBH), hvor Fe2+ er cofactor (3).

Fedtsyreforbrændingen er påvirket hos ME patienter, og der er fundet lave plasma værdier af carnitin hos patienterne. Læs blogindlæg:

ME minder om medfødt metabolisk defekt
http://followmeindenmark.blogspot.com/2019/02/me-minder-om-medfdt-metabolisk-defekt.html

Plasma niveauet af alfa-ketoglutarate var forhøjet hos ME patienter i Germain et al's metabolisme studie (4). Hvordan hænger det hele sammen?

Referencer

1) Salminen et al: 2-Oxoglutarate-dependent dioxygenases are sensors of energy metabolism, oxygen availability, and iron homeostasis: potential role in the regulation of aging process Cell Mol Life Sci. 2015 Oct;72(20):3897-914. doi: 10.1007/s00018-015-1978-z. Epub 2015 Jun 29. https://www.ncbi.nlm.nih.gov/pubmed/26118662

2) Loenarz and Schofield: Expanding chemical biology of 2-oxoglutarate oxygenases. Nat Chem Biol, 2008, 4, 3. https://www.ncbi.nlm.nih.gov/pubmed/18277970

3) Carnitine biosynthesis https://en.wikipedia.org/wiki/Carnitine_biosynthesis

4) Germain et al: Prospective Biomarkers from Plasma Metabolomics of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Implicate Redox Imbalance in Disease Symptomatology. Metabolites. 2018 Dec 6;8(4). pii: E90. doi: 10.3390/metabo8040090.https://www.ncbi.nlm.nih.gov/pubmed/30563204

REDOX og NO-sGC-cGMP-stivejen

Der findes en gammel hypotese om, at NO-sGC-cGMP-stivejen og hermed blodgennemstrømningen er påvirket hos ME patienter (1).

Nitrogenoxid (NO) er et gasformigt signalmolekyle, der har flere forskellige funktioner i kroppen. Soluble guanylate (eller guanylyl) cyclase (sGC) er receptor for NO. At den er soluble (opløselig) betyder, at den er intracellulær. På sGC molekylet findes et hæm-bindende område, der kan binde det gasformige molekyle NO. Hermed kan sGC producere guanosine 3’,5’-monophosphate (cGMP) fra guanosine triphosphate (GTP). Dette kaldes for NO-sGC-cGMP stivejen, som er relevant for kontrol af en lang række fysiologiske processer. F.eks. vil stimulation af sGC få glat muskulatur omkring blodkar til at slappe af. Der er udviklet lægemidler, der kan modulere sGC. De er målrettet tilstande, hvor dannelse af NO og NO tilgængelighed er mangelfuld (1).

På samme måde som hæmoglobin og IDO kan binde ilt via Fe2+ (læs to forrige blogindlæg), så kan sGC i ferro form sGC(Fe2+) binde NO. Når sGC bliver oxideret til sGC(Fe3+) kan NO ikke bindes.

• Aktiv ferro soluble Guanylate Cyclase: sGC(Fe2+) kan binde NO
• Inaktive ferri soluble Guanylate Cyclase: sGC sGC(Fe3+), kan IKKE binde NO

Celler i vaskulær glat muskulatur kan reducere den inaktive sGC(Fe3+) via cytochrome b5 reductase (CYB5B3), også kendt som methæmoglobin reductase. Hermed gendannes den NO-bindende sGC(Fe2+), se figur i reference 2 via link:

Schematic of Cyb5R3 regulating sGC heme redox state
Illustration shows Cyb5R3 sensitizes sGC to NO by reducing the sGC heme iron, controlling cGMP production and vessel relaxation.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527687/figure/F7/

Læs også:

Forhøjet methæmoglobin og "rod i redox" hos ME patienter
http://followmeindenmark.blogspot.com/2019/10/forhjet-methmoglobin-og-rod-i-redox-hos.html

REDOX status påvirker IDO enzym aktivitet
http://followmeindenmark.blogspot.com/2019/10/redox-status-pavirker-ido-enzym.html

Ergenor et al. NO-independent stimulators and activators of soluble guanylate cyclase: discovery and therapeutic potential. Nature Reviews. Drug Discovery. Vol 5, sept. 2006
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2225477/

Referencer

1) Blogindlæg af 24. marts 2016. Dysregulering af NO-sGC-cGMP-stivejen i ME/CFS http://followmeindenmark.blogspot.com/2016/03/dysregulering-af-no-sgc-cgmp-stivejen-i.html

2) Rahaman et al: Cytochrome b5 Reductase 3 Modulates Soluble Guanylate Cyclase Redox State and cGMP Signaling
Circ Res. 2017 Jul 7;121(2):137-148. doi: 10.1161/CIRCRESAHA.117.310705. Epub 2017 Jun 5.
https://www.ncbi.nlm.nih.gov/pubmed/28584062

REDOX status påvirker IDO enzym aktivitet

I forrige blogindlæg Forhøjet methæmoglobin og "rod i redox" hos ME patienter lærte vi, at hæmoglobin skal være i ferro (Fe2+) tilstand for at kunne binde ilt.

Enzymet indolamine-2,3-dioxygenase (IDO) binder ligeledes ilt via jern i ferro (Fe2+) form. IDO omsætter aminosyren tryptofan til N-formylkynurenine. IDO sætter to iltatomer (to ilt = di oxygen) ind i indolringen på plads nr. 2 og 3 i tryptofan (1):

Link til figur af den kemiske reaktion (1):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3280726/figure/sch1/

Ligesom hæmoglobin kan auto-oxideres til methæmoglobin i ferri (Fe3+) form, kan IDO auto-oxidere til en inaktiv ferri (Fe3+) form (2):

• Aktiv ferro indolamine-2,3-dioxygenase:: IDO(Fe2+), kan binde ilt
• Inaktiv ferri indolamine-2,3-dioxygenase: IDO(Fe3+)

I forrige blogindlæg lærte vi, at cytochrome b5 kan give en elektron til methæmoglobin Hgb(Fe3+), så den aktive iltbindende hæmoglobin Hgb(Fe2+) gendannes.

Cytochrome b5 kan også anvendes til at give en elektron til IDO(Fe3+), således at den aktive IDO(Fe2+) gendannes (3).


Et hold forskere har vist, at ud over cytochrome b5 kan polysulfider eller thiol-molekylet 3-mercaptoindol også anvendes til at regenere IDO enzymet, citat fra reference 2:

"To bind molecular oxygen and activate tryptophan, IDO1 must be in the reduced ferrous state, where it returns in its catalytic cycle without the need for additional reducing equivalents. And yet, if no reductant is supplied during multiple turnovers, IDO1 undergoes abortive autoxidation with loss of superoxide to produce the inactive ferric enzyme. The ferric IDO1 produced in this manner persists even in the reducing environment of cells, suggesting that self-limiting autoxidation is an adaption to prevent excessive activity. Further highlighting the importance of redox regulation in tryptophan metabolism, inactive ferric IDO1 is also prone to long-term inactivation through heme-loss, which likely accounts for the majority of cellular IDO1 found in the apo-form. Regeneration and maintenance of active, ferrous IDO1 in cells has been attributed to cytochrome b5. We sought to explore and understand what other cellular reductants might affect the IDO1 redox switch and, by implication, the immune response. Our initial efforts were motivated by recent work describing the hydrogen sulfide-mediated reduction of myoglobin, hemoglobin, heme oxygenase, and porphyrin complexes. Hydrogen sulfide binds to the ferric heme of these proteins to form a hydrosulfido complex that can then lead to reduction to the ferrous heme and production of sulfhydryl radical, a paradigm matching the requirements for IDO1 activation in cells. The final oxidized products of these reactions, polysulfides, have also gained attention with the discovery of their high, micromolar concentrations within cells and their remarkably versatile reactivity, including ferric heme reduction in cytochrome c."


Hvis hypotesen om ME-IDO-metabolic-trap er sand, kan polysulfider eller 3-mercaptoindol så anvendes til behandling af ME?


Har ME patienter et generelt redox reduktions-potentiale problem?

Læs også:

ME hypotese: The Metabolic Trap - den metaboliske fælde

The IDO Metabolic Trap Hypothesis for the Etiology of ME/CFS

Referencer

1) Efimov et el. The mechanism of substrate inhibition in human indoleamine 2,3 dioxygenase. J Am Chem Soc. 2012 Feb 15;134(6):3034-41. doi: 10.1021/ja208694g. Epub 2012 Feb 2.https://www.ncbi.nlm.nih.gov/pubmed/22299628

2) Nelp et el: Potent activation of indoleamine 2,3-dioxygenase by polysulfides. J Am Chem Soc. 2019 Sep 25;141(38):15288-15300. doi: 10.1021/jacs.9b07338. Epub 2019 Sep 11. https://www.ncbi.nlm.nih.gov/pubmed/31436417

https://pubs.acs.org/doi/10.1021/jacs.9b07338

https://pubs.acs.org/doi/suppl/10.1021/jacs.9b07338/suppl_file/ja9b07338_si_001.pdf

3) Maghzai et al: Cytochrome b5, not superoxide anion radical, is a major reductant of indoleamine 2,3-dioxygenase in human cells. J Biol Chem. 2008 May 2;283(18):12014-25. doi: 10.1074/jbc.M710266200. Epub 2008 Feb 25. https://www.ncbi.nlm.nih.gov/pubmed/18299324

Forhøjet methæmoglobin og "rod i redox" hos ME patienter

Konklusionen på Germain et al (2018) metabolisme studiet var, at det er "rod i redox" (1):
"Our hypothesis is that a disturbance in the redox status influences the status of chemical reaction donors and acceptors as well as their coenzymes such as NAD+/NADH, FAD+/FADH for dehydrogenases. Oxidases would obviously also be affected as catalyzers of redox reactions."

Ordet redox er en sammentrækning af reduktion og oxidation. Det handler om at flytte elektroner mellem kemiske forbindelser.

NAD+/NADH er et eksempel på et redox-par:

• NAD+ kan modtage en elektron
• NADH kan donere en elektron

Jern (latin: Ferrum) bliver også anvendt til kroppens redox-processer:

• Fe3+ er den trivalente jern-ion, også kaldet jern i ferri form (engelsk: ferric state). Fe3+ kan modtage en elektron.
• Fe2+ er den divalente jern-ion, også kaldet jern i ferro form (engelsk: ferrous state). Fe2+ kan donere en elektron.

Jern redox enzymer katalyserer skiftet mellem ferri og ferro formen:

• Ferrireduktaser reducerer Fe3+ til Fe2+
• Ferrooxidaser oxiderer Fe2+ til Fe3+

Hæmoglobin transporterer ilt (også kaldet oxygen eller O2) rundt i kroppen. Hæmoglobin indeholder jern. For at hæmoglobin kan binde ilt, skal jern være i ferro form (Fe2+). Hæmoglobin auto-oxiderer meget langsomt (ca. 3% pr. dag) til methæmoglobin, som er hæmoglobin i ferri form (Fe3+). Methæmoglobin kan ikke binde ilt (2):

• Hæmoglobin: Hgb(Fe2+), kan binde ilt
• Methæmoglobin: Hgb(Fe3+), kan IKKE binde ilt

Hvis niveauet af methæmoglobin bliver for højt, bliver man træt og motionsintolerant, fordi der ikke bliver båret ilt nok rundt i kroppen.

Som kompensation for dannelse af methæmoglobin har kroppen et enzym cytochrome b5, som reducerer methæmoglobin til hæmoglobin. Dvs. cytochrome b5 giver en elektron til methæmoglobin (Fe3+), så der dannes hæmoglobin (Fe2+), som igen kan binde ilt.

Idet cytochrome b5 har en elektron at give bort, er den i ferro form, og kaldes også for ferrocytochrome b5. Når ferrocytochrome br har givet sin elektron bort, bliver den til ferricytochrome b5.

Ferricytochrome b5 skal nu "genoplades" med en ny elektron for at blive til ferrocytochrome  b5. Cytochrome b5 får sin elektron fra NADH (3):

NADH + H⁺ + 2 ferricytochrome b₅ → NAD⁺ + 2 ferrocytochrome b₅


Enzymet der reducerer ferricytochrome b5 til ferrocytochrome b5 hedder cytochrome b5 reduktase, også kaldet methæmoglobin reduktase.

Germain et al (2018) henviser til et ældre studie, hvor der er målt forhøjede niveauer af methæmoglobn hos ME patienter (1):
"Richards et al.found that methaemoglobin was one of the principal components that differentiated their ME/CFS patients and control cohorts. This hemoglobin carries the oxidized form of the iron ion, namely, the ferric state instead of the ferrous state necessary for the hemoglobin to bind oxygen. Even though methaemoglobin measurements are not part of our dataset, it is intriguing to relate its oxidation state to a disturbed redox environment while the effect of the inability to bind oxygen could translate into anoxia and asphyxia."


I Richards et al's studiet står der (4):

Methaemoglobin was found to be the major component associated with variation in symptom expression in CFS patients (R(2) = 0.99, P <0.00001), which included fatigue, musculoskeletal symptoms, pain and sleep disturbance.

Måling af methæmoglobin

Det er let at måle methæmoglobin. Man tager en blodprøve og sprøjter den direkte ind i blodgas apparatet ABL800 og to minutter senere har man resultatet. Ethvert hospital har et blodgas apparat.

ABL800:
https://www.radiometer.dk/da-dk/videnscenter/h%C3%A5ndb%C3%B8ger-og-apps/acute-care-testing-handbook/critical-parameters-in-acute-care-testing

Referencer

1) Germain et al: Prospective Biomarkers from Plasma Metabolomics of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Implicate Redox Imbalance in Disease Symptomatology. Metabolites. 2018 Dec 6;8(4). pii: E90. doi: 10.3390/metabo8040090.
https://www.ncbi.nlm.nih.gov/pubmed/30563204

2) Umbreit: Methemoglobin--it's not just blue: a concise review. Am J Hematol. 2007 Feb;82(2):134-44. https://www.ncbi.nlm.nih.gov/pubmed/16986127

3) Wikipedia. Cytochrome b5 https://en.wikipedia.org/wiki/Cytochrome_b5

4) Blood parameters indicative of oxidative stress are associated with symptom expression in chronic fatigue syndrome. Richards RS, Roberts TK, McGregor NR, Dunstan RH, Butt HL
Redox Rep. 2000; 5(1):35-41.https://www.ncbi.nlm.nih.gov/pubmed/10905542

En ny biosensor viser, at SS-31 er et potentielt lægemiddel til ME

Dr. Ron Davis fra Standford Universitet og hans team har udviklet en nano-elektrisk biosensor (på engelsk populært kaldet "the nanoneedle"). Den kan vise om immunceller fra en blodprøve kommer fra ME patienter eller fra raske kontrolpersoner.

Immunceller fra både ME patienter og raske kontrolpersoner udsættes for salt-stress (også kaldet osmotisk stress) i biosensoren ved, at der tilsættes en natriumklorid-opløsning. Biosensoren måler et elektrisk signal (impedansen), som er et resultat af celleprocesser udløst af salt-stress.

Forskningen er beskrevet i denne artikel:
A nanoelectronics-blood-based diagnostic biomarker for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
https://www.pnas.org/content/116/21/10250.long

Dr. Ron Davis forsøger nu at finde et lægemiddel, der kan normalisere ME-cellers respons på salt-stress. Han afprøver forskellige lægemidler ved at tilsætte dem til blod fra ME patienter i biosensoren.

To lægemidler får celler fra ME blodprøver til at opføre sig normalt i biosensoren. Disse resultater blev fremlagt på Havard Symposium 2019:

Dr. Ron Davis Presents on ME/CFS Research Activities at Stanford at Inaugural Harvard Symposium

https://www.youtube.com/watch?v=02TUcGqTFAI&t=37s

Det ene lægemiddel er:  

Copaxone med indholdsstoffet hedder Glatirameracetate. Læs om det her: http://pro.medicin.dk/Medicin/Praeparater/2889

Det andet lægemiddel, som jeg synes er mest interessant, er:

SS-31, Szeto-Schiller Peptide 31, Elamipretide. Lægemidlet er endnu ikke godkendt, men der arbejdes med det på forsøgsbasis. Læs om det her: 

Mitochondrial dysfunction and oxidative stress in metabolic disorders - A step towards mitochondria based therapeutic strategies
https://www.ncbi.nlm.nih.gov/pubmed/27836629

The Mitochondrial Antioxidant SS-31 Modulates Oxidative Stress, Endoplasmic Reticulum Stress, and Autophagy in Type 2 Diabetes
https://www.ncbi.nlm.nih.gov/pubmed/31466264

Improving mitochondrial function with SS-31 reverses age-related redox stress and improves exercise tolerance in aged mice
https://www.ncbi.nlm.nih.gov/pubmed/30597195

The mitochondrial antioxidant SS-31 increases SIRT1 levels and ameliorates inflammation, oxidative stress and leukocyte-endothelium interactions in type 2 diabetes
https://www.ncbi.nlm.nih.gov/pubmed/30367115

SS-31 Provides Neuroprotection by Reversing Mitochondrial Dysfunction after Traumatic Brain Injury
https://www.ncbi.nlm.nih.gov/pubmed/30224944

From the muscle hypothesis to a muscle solution?
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6437437/

Novel Mitochondria-Targeting Peptide in Heart Failure Treatment: A Randomized, Placebo-Controlled Trial of Elamipretide
https://www.ncbi.nlm.nih.gov/pubmed/29217757

Therapies for mitochondrial diseases and current clinical trials
https://www.ncbi.nlm.nih.gov/pubmed/28943110

OMICS and iron metabolism in ME

Genomics in ME

Gene variants of TF, TFRC, and HPX have been identified as risk loci in ME patients (1):




Slide from: Whole Genome Sequencing and Analysis of ME/CFS
https://www.youtube.com/watch?v=nIJX-Q7w_Z4


Serotransferrin (usually just called transferrin), TF: iron-binding protein

Transferrin receptor, TFRC: plasma membrane protein that allows cellular uptake of iron-loaded transferrin

Hemopexin, HPX: a protein that binds free heme (or met-heme) and transport it to the liver for break-down and iron recovery.

Haptoglobin, HP: a protein that binds free hemoglobin and transport it to the liver for break-down and iron recovery.

Hemopexin and haptoglobin prevent heme toxicity.

Proteomics in ME

Serotransferrin precursor (gene: TF), number of unique peptides identified in the cerebrospinal fluid (table S1 in ref 2):

1) Controls: 105

2) ME patients: 141

3) Post treatment Lyme patients: 105

Transferrin variant fragment  (gene: TF), number of unique peptides identified in the cerebrospinal fluid (table S1 in ref 2):

1) Controls: 104

2) ME patients: 130

3) Post treatment Lyme patients: 99

Transferrin receptor protein 1 (gene: TFRC), number of unique peptides identified in the cerebrospinal fluid (table S1 in ref 2):

1) Controls: 1

2) ME patients: 2

3) Post treatment Lyme patients: 3

Haptoglobin precursor (gene: HP) , number of unique peptides identified in the cerebrospinal fluid (table S1 in ref 2).

1) Controls: 30

2) ME patients: 39

3) Post treatment Lyme patients: 34

Hemopexin precursor (gene: HPX) , number of unique peptides identified in the cerebrospinal fluid (table S1 in ref 2).

1) Controls: 61

2) ME patients: 197

3) Post treatment Lyme patients: 189

Another proteome study on cerebrospinal fluid from ME patients also showed increased levels of hemopexin and haptoglobin (3).

Metabolomics in ME

A metabolomic study on plasma from ME patients showed increased levels of heme (4).

Methemoglobin in ME

A study showed increased levels of methemoglobin in ME patients. Methemoglobin was found to be the major component associated with variation in symptom expression in ME patients (R(2) = 0.99, P <0.00001), which included fatigue, musculoskeletal symptoms, pain and sleep disturbance (5).

Activated macrophages produce an inducible NO synthase (iNOS or NOS2). This NO produced during inflammation and other oxygen reactive species results in conversion of hemoglobin to methemoglobin, and this consequently results in an increased rigidity of the red blood cell (RBC) with increased RBC lysis (6).  

Methemoglobin is an activator of endothelial cells by stimulation of IL-6, IL-8 and E-selectin (6).

Red blood cell deformability is diminished in ME patients (7).

Genomics, proteomics and transcriptomics show the iNOS pathway is upregulated in ME (8).

References:

1) Whole Genome Sequencing and Analysis of ME/CFS https://www.youtube.com/watch?v=nIJX-Q7w_Z4

2) Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issuehttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0017287

3) Baraniuk et al: A Chronic Fatigue Syndrome - related proteome in human cerebrospinal fluid. BMC Neurol. 2005 Dec 1;5:22. https://www.ncbi.nlm.nih.gov/pubmed/16321154

4) Germain et al: Prospective Biomarkers from Plasma Metabolomics of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Implicate Redox Imbalance in Disease Symptomatology. Metabolites. 2018 Dec 6;8(4). pii: E90. doi: 10.3390/metabo8040090.
https://www.ncbi.nlm.nih.gov/pubmed/30563204

5) Richards et al: Blood parameters indicative of oxidative stress are associated with symptom expression in chronic fatigue syndrome. Redox Rep. 2000;5(1):35-41. https://www.ncbi.nlm.nih.gov/pubmed/10905542

6) Umbreit: Methemoglobin--it's not just blue: a concise review. Am J Hematol. 2007 Feb;82(2):134-44. https://www.ncbi.nlm.nih.gov/pubmed/16986127

7) Saha et al: Red blood cell deformability is diminished in patients with Chronic Fatigue Syndrome. Clin Hemorheol Microcirc. 2019;71(1):113-116. doi: 10.3233/CH-180469. https://www.ncbi.nlm.nih.gov/pubmed/30594919

8) Genomics, proteomics and transcriptomics show the iNOS pathway is upregulated in ME. https://followmeindenmark.blogspot.com/2019/09/genomics-proteomics-and-transcriptomics.html

Genomics and the cytokine network in ME

Genomics in ME

Gene variants of IL12B, IL1B and IL4R have been identified as a risk loci in ME (1):

Slide from: Whole Genome Sequencing and Analysis of ME/CFS
https://www.youtube.com/watch?v=nIJX-Q7w_Z4

Cytokines in ME

Plasma cytokine levels have been measured in ME patients with short-duration illness (≤3 years) and ME patients with long-duration illness (>3 years) (2).

IL-12B (IL-12p40) was increased in short-duration and decreased in long-duration compared to normal controls.

IL-1β was decreased in long-duration compared to short-duration and normal controls (2).

IL4 was increased in short-duration and decreased in long-duration compared to normal controls (2).

Interferon-γ (IFNγ) was decreased in long-duration compared to short-duration and normal controls (2).

Cytokines and IDO1

IL-12B stimulate the production of IFNγ, and  IFNγ induce IDO1 activity (3).

IDO1 is inhibited by IL-4 (3).

Do the risk loci play a role in the ME-IDO-metabolic trap hypothesis?

Further reading:

Genomics, proteomics and transcriptomics show the iNOS pathway is upregulated in ME
http://followmeindenmark.blogspot.com/2019/09/genomics-proteomics-and-transcriptomics.html

References:

1) Whole Genome Sequencing and Analysis of ME/CFS https://www.youtube.com/watch?v=nIJX-Q7w_Z4

2) Hornig et al: Distinct plasma immune signatures in ME/CFS are present early in the course of illness. Sci Adv. 2015 Feb;1(1). pii: e1400121.  https://www.ncbi.nlm.nih.gov/pubmed/26079000

3) Opitz et al: Tryptophan degradation in autoimmune diseases. Cell Mol Life Sci. 2007 Oct;64(19-20):2542-63. https://www.ncbi.nlm.nih.gov/pubmed/17611712

Genomics, proteomics and transcriptomics show the iNOS pathway is upregulated in ME

Activated macrophages produce an inducible NO synthase (iNOS or NOS2).  Although iNOS was originally identified and characterized in macrophages, it is present in numerous cell types including endothelial cells, fibroblasts, vascular smooth muscle cells and cardiac myocytes (1).

Genomics in ME

A gene variant of iNOS has been identified as a risk locus in ME (2):

Slide from. Whole Genome Sequencing and Analysis of ME/CFS

https://www.youtube.com/watch?v=nIJX-Q7w_Z4 

Proteomics in ME

The pathway "Production of NO and ROS in macrophages" was upregulated in the cerebrospinal fluid from ME patients (table S6 in ref 3).

Transcriptomics in ME

Functional Network Analysys of gene transcripts from ME immune cells showed thar the pathway "Production of NO and ROS in macrophages" was enriched (p-value = 0,000018) (4).

Macrophages and the ME-IDO-metabolic trap

The ME-IDO metabolic trap hypothesis tell us that the kynurenic pathway may be blocked in dendritic cells and macrophages. This means decreased metabolites from the pathway (5).

During inflammation and resolution of inflammation, this may be going on in normal cells (6) :

• Increased IDO activity
• Increased kynurenic acid (KYNA) production
• Increased GPR35 activation (KYNA activates GPR35)
• Decreased iNOS expression

Figure 2 from ref 6 Wirthgen et al (2018).


Is this what is going on in ME macrophages???:

• Decreased IDO activity
• Decreased KYNA production
• Decreased GPR35 activation
• Increased iNOS expression

References:

1) iNOS signaling: https://www.qiagen.com/us/shop/genes-and-pathways/pathway-details/?pwid=252

2) Whole Genome Sequencing and Analysis of ME/CFS https://www.youtube.com/watch?v=nIJX-Q7w_Z4

3) Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issuehttps://journals.plos.org/plosone/article?id=10.1371/journal.pone.0017287

4) Sweetman et al: Changes in the transcriptome of circulating immune cells of a New Zealand cohort with myalgic encephalomyelitis/chronic fatigue syndrome. Sweetman et al: Int J Immunopathol Pharmacol. 2019 Jan-Dec;33:2058738418820402. doi: 10.1177/2058738418820402.
https://www.ncbi.nlm.nih.gov/pubmed/30791746

5) Kashi AA Davis RW and, Phair RD: The IDO Metabolic Trap Hypothesis for the Etiology of ME/CFS. Diagnostics (Basel). 2019 Jul 26;9(3). pii: E82. doi: 10.3390/diagnostics9030082. https://www.mdpi.com/2075-4418/9/3/82

Metabolic Traps in ME/CFS - Research Update by Dr. Robert Phair
https://www.youtube.com/watch?v=Quh-77gvw4Q

6) Wirthgen E Hoeflich A, Rebl A, Günther J.: Kynurenic Acid: The Janus-Faced Role of an Immunomodulatory Tryptophan Metabolite and Its Link to Pathological Conditions
Front Immunol. 2018 Jan 10;8:1957. doi: 10.3389/fimmu.2017.01957. eCollection 2017.
https://www.frontiersin.org/articles/10.3389/fimmu.2017.01957/full

Does OXA1L, MRM2 and MRRF protein activity compensate for complex V inefficiency in ME patient cells?

ATP synthesis by Complex V is less efficient in ME/CFS cells. The other mitochondrial complexes work harder to compensate (1).

Is this problem reflected in previous ME research?

OXA1L

Oxidase (cytochrome c) assembly 1-like (OXA1L) is a mitochondrial inner membrane protein. It is required for the insertion of integral membrane proteins into the mitochondrial inner membrane. Essential for the activity and assembly of cytochrome oxidase. Required for the correct biogenesis of complex V and complex I in mitochondria (2).

Knockdown of human Oxa1L impairs the biogenesis of complex V and NADH:ubiquinone oxidoreductase (3).

The C-terminal approximately 100-amino acid tail of Oxa1L (Oxa1L-CTT) binds to mitochondrial ribosomes and plays a role in the co-translational insertion of mitochondria-synthesized proteins into the inner membrane (4).

The gene OXA1L had changed DNA methylation profile and increased foldchange (2,01) in CD4+ T-cells from ME patients (5).

MRM2/FTSJ2

Mitochondrial rRNA methyltransferase 2 (also known as FTSJ2) is involved in mitoribosome assembly (6).

Defective MRM2 causes MELAS-like clinical syndrome (MELAS = mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (7).

The gene MRM2 had changed DNA methylation profile and increased foldchange (2,12) in CD4+ T cells from ME patients (5).

The gene MRM2 was hypomethylated (3'UTR) in peripheral mononuclear cells (PBMC) from ME patients (8).

MRRF

Mitochondrial ribosome-recycling factor (MRRF) is responsible for the release of ribosomes from messenger RNA at the termination of protein biosynthesis. May increase the efficiency of translation by recycling ribosomes from one round of translation to another (2).

MRRF is essentiel for cell viability and depletion of MRRF leads to loss of mitochondrial complexes (9).

MRRF gene expresseion was increased in PBMC from ME patients (10, 11). 

Does OXA1L, MRM2 and MRRF protein activity compensate for complex V inefficiency in ME patient cells?

References

1) Missailidis, D.; Annesley, S.J.; Allan, C.Y.; Sanislav, O.; Lidbury, B.A.; Lewis, D.P.; Fisher, P.R. An isolated Complex V defect and dysregulated mitochondrial function in immortalized lymphocytes from ME/CFS patients. Submitted 2019.

Specific Mitochondrial Respiratory Defects & Compensatory Changes in ME/CFS Patient Cells
https://www.youtube.com/watch?v=SjK39QCPeeY

2) Genecards: https://www.genecards.org/

3) Stiburek et al. Knockdown of human Oxa1l impairs the biogenesis of F1Fo-ATP synthase and NADH:ubiquinone oxidoreductase. J Mol Biol. 2007 Nov 23;374(2):506-16. Epub 2007 Sep 20. https://www.ncbi.nlm.nih.gov/pubmed/17936786

4) Hauge et al: Properties of the C-terminal tail of human mitochondrial inner membrane protein Oxa1L and its interactions with mammalian mitochondrial ribosomes. J Biol Chem. 2010 Sep 3;285(36):28353-62. doi: 10.1074/jbc.M110.148262. Epub 2010 Jul 2. https://www.ncbi.nlm.nih.gov/pubmed/20601428

5) Brenu et al: Methylation profile of CD4+ T cells in CFS/ME. J. Clin Cell Immunol 5, 228https://www.omicsonline.org/open-access/methylation-profile-of-cd-t-cells-in-chronic-fatigue-syndromemyalgic-encephalomyelitis-2155-9899.1000228.php?aid=27598

6) Rorbach et al: MRM2 and MRM3 are involved in biogenesis of the large subunit of the mitochondrial ribosome. Mol Biol Cell, 2014, 25, 17.

7) Garone et al: Defective MRM2 causes MELAS-like clinical syndrome. Hum Mol Genet, 2017, 26, 21.

8) Trivedi et al: Identification of ME/CFS - associated DNA methylation patterns. Plos One 2018, 13, 7.

9) Rorbach et al: The human mitochondrial ribosome recycling factor is essential for cell viability. Nucleic Acids Research, 2008, 36, 18.

10) Kerr et al: Gene expression subtypes in patients with CFS/ME. JID, 2008, 197.

11) Frampton et al: Assessment of a 44 gene classifier for the evaluation of CFS from PBMC gene expression. Plos one, 2011, 6, 3.

AMPD3 in ME

Adenosine monophosphate deaminase (AMPD) converts AMP to inosine monophosphate (IMP).

The AMP deaminase gene family:
AMPD1, muscle (m) isoform
AMPD2, liver (l) cells isoform
AMPD3, erothrocyte (e) isoform

The isoforms are named after their predominant location, but are also expressed in other tissue. Fx. AMPD3 is also expressed in muscles.

The purine nucleotide cycle of muscles consist of the conversion of AMP→IMP→AMP and requires AMP deaminase. Flux through this cycle increases during exercise.

Genomics in ME

A gene variant of AMPD3 has been identified as a risk locus in ME (1):

Slide from. Whole Genome Sequencing and Analysis of ME/CFS

https://www.youtube.com/watch?v=nIJX-Q7w_Z4

Epigenomics in ME

The genes AMPD2 and AMPD3 were epigenetic changed in peripheral blood mononuclear cells (PBMC) from ME patients in two studies (2, 3). Some of the DNA methylations in AMPD2 and AMPD3 were related to quality of life in the ME patients (3). AMPD2 and AMPD3 were differntially methylated in PBMC from ME patient subtypes (4).

Transcriptomics in ME

AMPD3 gene expression was downregulated in biopsies from the vastus lateralis muscle in ME patients (5).

Metabolomics in ME

Metabolic profiling of ME patients showed disturbances in purine metabolism (6, 7, 8). Fx, IMP was decreased in plasma from ME patients (8). 

HDAC3 and AMPD3

Depletion of histone deacetylase 3 (HDAC3) in skeletal muscle in mice causes lower glucose utilization and greater lipid oxidation. AMPD3 is involved in the regulation of the fuel switch (9).

Interestingly, very low density lipoprotein receptor (VLDLR) was found to be up-regulated in the ME muscle biopsies in ref 5. VLDLR is responsible for VLDL uptake into the fiber and is involved in the primary pathway of fatty acid transport in skeletal muscle (5). 

6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) was down-regulated (5). PFKFB3 belongs to a family of bifunctional proteins that are involved in both the synthesis and degradation of fructose-2,6-bisphosphate, a regulatory molecule that controls glycolysis.

Transducin beta like 1 X-linked receptor 1 (TBL1XR1) was up-regulatede in women and down-regulted in men (5). TBL1XR1 is thought to be a component of both nuclear receptor corepressor (N-CoR) and HDAC3 complexes.

ME is associated with purine and histone deacetylation dysregulation (10). 

References:

1) Whole Genome Sequencing and Analysis of ME/CFS https://www.youtube.com/watch?v=nIJX-Q7w_Z4

2) ) de Vega et al: Epigenetic modifications and glucocorticoid sensitivity in ME/CFS. BMC Medical Genomics, 2017, 10, 11 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5324230/

3) Trivedi et al: Identification of ME/CFS - associated DNA methylation patterns. Plos One 2018, 13, 7 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201066

4) de Vega et al: Integration of DNA methylation & health scores identifies subtypes in ME/CFS. Epigenomics 2018, 10, 5 https://www.futuremedicine.com/doi/full/10.2217/epi-2017-015

5) Pietrangelo et al: Transcription profile analysis of vastus lateralis muscle from patients with chronic fatigue syndrome. Int J Immunopathol Pharmacol. 2009 Jul-Sep;22(3):795-807. https://www.ncbi.nlm.nih.gov/pubmed/19822097

6) Naviaux RK, Naviaux JC, Li K, Bright AT, Alaynick WA, Wang L, Baxter A, Nathan N et al (2016) Metabolic features of chronic fatigue syndrome. Proc Natl Acad Sci U S A 113:E5472–E5480. https://doi.org/10.1073/pnas.1607571113

7) Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371 https://pubs.rsc.org/en/Content/ArticleLanding/2017/MB/C6MB00600K#!divAbstract

8) Germain et al: Prospective Biomarkers from Plasma Metabolomics of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Implicate Redox Imbalance in Disease Symptomatology. Metabolites. 2018 Dec 6;8(4). pii: E90. doi: 10.3390/metabo8040090.
https://www.ncbi.nlm.nih.gov/pubmed/30563204

9) Hong et al: Dissociation of muscle insulin sensitivity from exercise endurance in mice by HDAC3 depletion. Nat Med. 2017 Feb;23(2):223-234. doi: 10.1038/nm.4245. Epub 2016 Dec 19. https://www.ncbi.nlm.nih.gov/pubmed/27991918

10) Mcgregor et al: Post-Exertional Malaise Is Associated with Hypermetabolism, Hypoacetylation and Purine Metabolism Deregulation in ME/CFS Cases Diagnostics (Basel). 2019 Jul 4;9(3). pii: E70. doi: 10.3390/diagnostics9030070. https://www.ncbi.nlm.nih.gov/pubmed/31277442

GPR35, ATPase inhibitor IF1 and ATP synthase subunits

The ME hypothesis "the metabolic trap" tell us that IDO function in immune cells may be compromised (1).

IDO1 and IDO2 catalyze the first step in the kynurenine pathway: The conversion of tryptophan to N-formyl-kynurenine. N-formyl-kynurenine can be converted to kynurenine (KYN). KYN can be further processed to kynurenic acid (KYNA).

ATP synthesis by Complex V is less efficient in ME/CFS cells (2).

ATP synthase (also known as Complex V or F(1)F(o)-ATPase ) consists of several subunits (3). These subunits interact with the ATPase Inhibitory Factor.

The ATPase Inhibitory Factor (ATPIF1) is a master regulator of energy metabolism and of cell survival. (4).

The kynurenic acid responsive GPR35 interacts with ATPIF1. And ATPIF1 interacts with ATP5B (5). 

The gene GPR35 is hypomethylated in peripheral blood mononuclear cells (PBMC) from ME patients (p-value = 6,44E-08, FDR = 0,0029) (6).

ATP synthase subunit beta expression was upregulated in ME patients (7).

Figure from Genecards STRING interaction network (5).


GPR35: G-protein coupled receptor 35; Acts as a receptor for kynurenic acid, an intermediate in the tryptophan metabolic pathway. The activity of this receptor is mediated by G-proteins that elicit calcium mobilization and inositol phosphate production through G(qi/o) proteins (5).

ATPIF1: ATPase inhibitor, mitochondrial; Endogenous F(1)F(o)-ATPase inhibitor limiting ATP depletion when the mitochondrial membrane potential falls below a threshold and the F(1)F(o)-ATP synthase starts hydrolyzing ATP to pump protons out of the mitochondrial matrix. Required to avoid the consumption of cellular ATP when the F(1)F(o)-ATP synthase enzyme acts as an ATP hydrolase. Indirectly acts as a regulator of heme synthesis in erythroid tissues- regulates heme synthesis by modulating the mitochondrial pH and redox potential (5).

ATP5B: ATP synthase subunit beta, mitochondrial; Mitochondrial membrane ATP synthase (F(1)F(0) ATP synthase or Complex V) produces ATP from ADP in the presence of a proton gradient across the membrane which is generated by electron transport complexes of the respiratory chain. F-type ATPases consist of two structural domains, F(1) - containing the extramembraneous catalytic core, and F(0) - containing the membrane proton channel, linked together by a central stalk and a peripheral stalk (5).


Is something going on in the ATP5B - ATPIF1 - GPR35 interaction network in  ME?

Further reading: 

Is the kynurenic acid responsive Gpr35 involved in the ME pathomechanism?
http://followmeindenmark.blogspot.com/2019/06/is-kynurenic-acid-responsive-gpr35.html

Complex V is down in ME - does it also explain Electromagnetic Hypersensitivity?
http://followmeindenmark.blogspot.com/2019/07/complex-v-is-down-in-me-does-it-also.html

Complex V is down in ME - does it explain Chemical Intolerance?
http://followmeindenmark.blogspot.com/2019/07/complex-v-is-down-in-me-does-it-explain.html

Mutations in the IDO2 gene and DNA methylations in genes in the NAD/NADP synthesis pathway in ME
http://followmeindenmark.blogspot.com/2019/07/mutations-in-ido2-gene-and-dna.html

CTLA-4 induces IDO and SOCS3 drives degradation of IDO
http://followmeindenmark.blogspot.com/2019/06/ctla-4-induces-ido-and-socs3-drives.html

References:

1) Kashi AA Davis RW and, Phair RD: The IDO Metabolic Trap Hypothesis for the Etiology of ME/CFS. Diagnostics (Basel). 2019 Jul 26;9(3). pii: E82. doi: 10.3390/diagnostics9030082. https://www.mdpi.com/2075-4418/9/3/82

Metabolic Traps in ME/CFS - Research Update by Dr. Robert Phair
https://www.youtube.com/watch?v=Quh-77gvw4Q

2) Missailidis, D.; Annesley, S.J.; Allan, C.Y.; Sanislav, O.; Lidbury, B.A.; Lewis, D.P.; Fisher, P.R. An isolated Complex V defect and dysregulated mitochondrial function in immortalized lymphocytes from ME/CFS patients. Submitted 2019.

Specific Mitochondrial Respiratory Defects & Compensatory Changes in ME/CFS Patient Cells
https://www.youtube.com/watch?v=SjK39QCPeeY

3) Wikipedia: ATP synthase: https://en.wikipedia.org/wiki/ATP_synthase

4) García-Bermúdez J, Cuezva JM.:The ATPase Inhibitory Factor (IF1) is a master regulator of energy metabolism and of cell survival. Biochim Biophys Acta. 2016 Aug;1857(8):1167-1182. doi: 10.1016/j.bbabio.2016.02.004. Epub 2016 Feb 12.
https://www.sciencedirect.com/science/article/pii/S0005272816300238?via%3Dihub#f0020

5) Genecards STRING interaction network, GPR35 https://www.genecards.org/

6) Trivedi et al: Identification of ME/CFS - associated DNA methylation patterns.
Plos One 2018, 13, 7 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201066

7) Ciregia et al: Bottom-up proteomics suggests an association between differential expression of mitochondrial proteins and chronic fatigue syndrome. Transl Psychiatry. 2016 Sep 27;6(9):e904. doi: 10.1038/tp.2016.184.  https://www.nature.com/articles/tp2016184

Complex V is down in ME - does it also explain Electromagnetic Hypersensitivity?

Complex V

Complex V (also known as ATP synthase or F0F1ATPase) is working less efficiently in cells from ME patients (1).

Chemical Intolerance and Electromagnetic Hypersensitivity in ME

ME patients have chemical intolerance (CI), also knowns as multiple chemical sensitivity (MCS). 

I have asked the question:
Complex V is down in ME - does it explain Chemical Intolerance?
http://followmeindenmark.blogspot.com/2019/07/complex-v-is-down-in-me-does-it-explain.html

Several ME patients also have electromagnetic hypersensitivity (EHS). It has been hypothesized that EHS and CI are two etiopathogenic aspects of a unique pathological disorder (2, 3).

Maybe ME, CI and EHS are a unique "Complex V-disease"?

Electromagnetic Fields and Complex V

Humans are exposed to electromagnetic fields (EMFs) from: Radio and television stations and receivers, radar, computers, Wi-Fi antennas, mobile phones, microwave ovens, and many devices used in medicine and industry. Our blood is just under the skin and is exposed to EMFs all the time.

Lassaivia et al have investigated peripheral blood lympho-monocytes exposed to EMFs at 1.8 GHz frequency and 200 V/m electric field strength. Respirometric measurements of mitochondrial activity in intact lympho-monocytes showed:

• An in increase of the resting oxygen consumption rate after 20 h of exposure, which was coupled to a significant increase of the FoF1-ATP synthase-related oxygen consumption.
• At lower time-intervals of EMFs exposure (i.e. 5 and 12 h) a large increase of the proton leak-related respiration was observed which, however, recovered at control levels after 20 h exposure.
• No significant variations in the mitochondrial mass/morphology was observed in EMFs-exposed lympho-monocytes.
• Altered redox homeostasis was shown in EMFs-exposed lympho-monocytes, which progressed differently in nucleated cellular subsets.

The results suggest the occurrence of adaptive mechanisms put in action, likely via redox signaling, to compensate for early impairments of the oxidative phosphorylation system caused by exposure to EMFs (4).

ME and Complex V

Fisher et al have investigated lymphoblasts from ME patients and found specific mitochondrial respiratory defects and compensatory changes (5).

Respirometry of immortalized ME patient lymphocytes (lymphoblasts) showed:

• Mitochondrial ATP synthesis by Complex V is inefficient, representing a significantly lower proportion of the basal mitochondrial respiratory activity.
• Absolute ATP synthesis rates (pmol/min) were not significantly lower than in control cells, while glycolysis rates and steady state ATP levels were unchanged.
• There was a significant increases in maximum respiratory capacity, including Complex I activity.
• “Nonmitochondrial” O2 consumption by other cellular enzymes was also elevated. 

The results suggest that ME/CFS cells compensate for the reduced efficiency of ATP synthesis by upregulating mitochondrial respiratory capacity.

The mitochondrial membrane “mass” and genome copy number were unchanged. Thus ME/CFS cells do not have “more” mitochondria, but their mitochondria have greater respiratory capacity. This increased capacity is underutilized because of the Complex V defect, so that the respiratory “spare capacity” was increased and the mitochondrial membrane potential was elevated (5).

I have a new question:

Can continous exposure from electromagnetic fields in the environment put further strain on a compromised complex V in ME patient cells?

A magnetic field is able to influence Complex V

Interestingly, a team of Japanese scientists have succeeded in attaching magnetic beads to the stalks of F1 -ATPase isolated in vitro, which rotated in presence of a rotating magnetic field. F1 -ATPase synthesized ATP from ADP and Pi when rotated in a clockwise direction at a rate of about 5 molecules per second. Additionally, ATP was hydrolyzed when the stalks were rotated in the counterclockwise direction or when they were not rotated at all (6, ref 26 in ref 7).

References

1) Missailidis, D.; Annesley, S.J.; Allan, C.Y.; Sanislav, O.; Lidbury, B.A.; Lewis, D.P.; Fisher, P.R. An isolated Complex V defect and dysregulated mitochondrial function in immortalized lymphocytes from ME/CFS patients. Submitted 2019.

Specific Mitochondrial Respiratory Defects & Compensatory Changes in ME/CFS Patient Cells
https://www.youtube.com/watch?v=SjK39QCPeeY

2) Belpomme D, Campagnac C, Irigaray P. : Reliable disease biomarkers characterizing and identifying electrohypersensitivity and multiple chemical sensitivity as two etiopathogenic aspects of a unique pathological disorder. Rev Environ Health. 2015;30(4):251-71. doi: 10.1515/reveh-2015-0027. https://www.ncbi.nlm.nih.gov/pubmed/26613326

3) De Luca C, Thai JC, Raskovic D, Cesareo E, Caccamo D, Trukhanov A, Korkina L   Mediators Inflamm.: Metabolic and genetic screening of electromagnetic hypersensitive subjects as a feasible tool for diagnostics and intervention.  2014;2014:924184. doi: 10.1155/2014/924184. Epub 2014 Apr 9. https://www.ncbi.nlm.nih.gov/pubmed/24812443

4) Lassaivia et al: Exposure to 1.8 GHz electromagnetic fields affects morphology, DNA-related Raman spectra and mitochondrial functions in human lympho-monocytes. PLOS ONE. February 20, 2018.https://doi.org/10.1371/journal.pone.0192894

5) International research symposiym: Mitochondrial function and signalling “Specific mitochondrial respiratory defects and compensatory changes in immortalized ME/CFS patient lymphocytes.” Speaker: Professor Paul Fisher, Latrobe University, VIC, Australia
https://emerge.org.au/wp-content/uploads/2019/03/2019-Symposium-Programme.pdf

6) Itoh et al: Mechanically driven ATP synthesis by F1-ATPase. Nature. 2004 Jan 29;427(6973):465-8. https://www.nature.com/articles/nature02212

7) Neupane et al: ATP Synthase: Structure, Function and Inhibition. De Gruyter 2019.
https://www.degruyter.com/view/j/bmc.2019.10.issue-1/bmc-2019-0001/bmc-2019-0001.xml

Complex V is down in ME - does it explain Chemical Intolerance?

Complex V

Complex V (also known as ATP synthase or F0F1ATPase) is working less efficiently in cells from ME patients (1).

The ATPase Inhibitory Factor 1 (IF1) is the physiological inhibitor of the mitochondrial ATP synthase (complex V). IF1 is a mitochondrial protein with very short half-life. It is tissue-specifically expressed and primarily controlled at posttranscriptional levels. Overexpressing of IF1 leads to inhibition of the ATP synthase and the reprograming of energy metabolism to an enhanced glycolysis. This reprogramming may protect cells from cytotoxic insults (2).

Figur 1B from reference 2 shows how IF1 binds the ATP synthase and inhibits ATP synthesis. Figur 1A: The gene ATP5IF1 encodes IF1. In mice IF1 is degraded by immediate early response gene X-1 (IEX-1). The human homolog af IEX-1 is immediate early response 3 (IER3), but IER3 do not degrade IF1 (2).

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6156145/figure/F1/

Chemical intolerance - is IF1 involved?

ME patients have chemical intolerance (CI), also knowns as multiple chemical sensitivity (MCS). Fx, ME patients do not tolerate smoke and exhaust fumes.

Polycyclic aromatic hydrocarbons (PAHs) are found in the environmental contaminants. It has been hypothesized  that dysregulation of the aryl hydrocarbon receptor is involved in chemical intolerance (3).

Benzo[a]pyrene (B[a]P) is a prototype molecule of polycyclic aromatic hydrocarbons. B[a]P induce IF1 expression and metabolic reprogramming towards glycolysis in rat liver cells. The process may also involve β2-adrenergic receptor and aryl hydrocarbon receptor activation (4).






Figure 6 from reference 4: A proposed model for the B[a]P-mediated metabolic reprogramming and its role in cell fate determination in F258 rat hepatic epithelial cells.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5428028/figure/Fig6/

Can PAH-induced IF1 upregulation put further strain on a compromised complex V in ME patient cells?

Can auto-antibodies against adrenergic receptors upregulate IF1 activity in ME patient cells?

Mutant mice with an active IF1 are partially protected from cytotoxic insults - such as quinolinic acid (2). Interestingly quinolinic acid is a kynurenine metabolite which may be dysregulated in ME patients according to the IDO metabolic trap hypothesis (5).

References

1) Missailidis, D.; Annesley, S.J.; Allan, C.Y.; Sanislav, O.; Lidbury, B.A.; Lewis, D.P.; Fisher, P.R. An isolated Complex V defect and dysregulated mitochondrial function in immortalized lymphocytes from ME/CFS patients. Submitted 2019.

Specific Mitochondrial Respiratory Defects & Compensatory Changes in ME/CFS Patient Cells

https://www.youtube.com/watch?v=SjK39QCPeeY

2) García-Aguilar A and Cuezva JM (2018).  A Review of the Inhibition of the Mitochondrial ATP Synthase by IF1 in vivo: Reprogramming Energy Metabolism and Inducing Mitohormesis. Front. Physiol. 9:1322. doi: 10.3389/fphys.2018.01322

https://www.frontiersin.org/articles/10.3389/fphys.2018.01322/full

3) de Luca et al: Biological definition of multiple chemical sensitivity from redox state and cytokine profiling and not from polymorphisms of xenobiotic-metabolizing enzymes. Toxicol Appl Pharmacol. 2010 Nov 1;248(3):285-92. doi: 10.1016/j.taap.2010.04.017. Epub 2010 Apr 27. https://www.ncbi.nlm.nih.gov/pubmed/20430047

4) Kévin Hardonnière, Morgane Fernier, Isabelle Gallais, Baharia Mograbi, Normand Podechard, Eric Le Ferrec, Nathalie Grova, Brice Appenzeller, Agnès Burel, Martine Chevanne,, Odile Sergent, Laurence Huc, Sylvie Bortoli & Dominique LagadicGossmann (2017): Role for the ATPase inhibitory factor 1 in the environmental carcinogen-induced Warburg phenotype. Nature scientific reports | 7: 195 | DOI:10.1038/s41598-017-00269-7

https://www.nature.com/articles/s41598-017-00269-7

5) Metabolic Traps in ME/CFS - Research Update by Dr. Robert Phair https://www.youtube.com/watch?v=Quh-77gvw4Q

IDO-ME hypotesen er forenelig med AHR-MCS hypotesen (in danish - use the english references in the blog post)

http://followmeindenmark.blogspot.com/2019/06/ido-me-hypotesen-er-forenelig-med-ahr.html

Kynurenine metabolisme påvirkes af motion (in danish - use the english references in the blog post)

http://followmeindenmark.blogspot.com/2019/06/kynurenine-metabolisme-pavirkes-af.html

Tryptofan metabolitten kynureninsyre har immunmodulerende egenskaber (in danish - use the english references in the blog post)

http://followmeindenmark.blogspot.com/2019/06/tryptofan-metabolitten-kynureninsyre.html

Is the kynurenic acid responsive Gpr35 involved in the ME pathomechanism?

http://followmeindenmark.blogspot.com/2019/06/is-kynurenic-acid-responsive-gpr35.html