søndag den 31. december 2017

F2 og F2R

Komplement og koagulations kaskaden bliver aktiveret ved et inflammatorisk respons. Dette afspejles i proteom studiet af cerebrospinalvæske fra ME patienter. Thrombin er en del af dette respons. Studiet viste, at fragment af prothrombin precusor (F2) var forhøjet. Værdi for ME patienter: 126, normal værdi: 27. (1)

Genet for koagulations faktor II trombin receptor (F2R) er fundet hypomethyleret hos ME patienter. Det er gen nr. 9 på listen over epigenetisk ændrede gener, der relaterer til ME patienters livskvalitet (2).

Alfa-2-macroglobulin (se sidste blogindlæg) fungerer inhibitorisk i koagulationsprocessen.

Er der noget her der hænger sammen?

Referencer:

  1. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue
  2. Vega et al: Epigenetic modifications and glucocorticoid sensitivity in ME/CFS. BMC Medical Genomics, 2017, 10, 11

lørdag den 30. december 2017

alfa-2-macroglobulin og anti-sense RNA

de Vega et al fandt 12.608 forskelligt methylerede steder i generne hos ME patienter i forhold til raske kontrolpersoner. Da disse ændringer blev relateret til ME patienternes livskvalitet kom genet for alfa-2-macroglobulin anti-sense RNA 1 ud som nr. 5-hypermethyleret (tabel S7 i ref 1).

Anti-sense RNA er komplementær til mRNA med det formål at inhibere translationen af mRNA. Dvs hvis et anti-sense gen bliver nedreguleret ved en hypermethylering, så er der ikke noget til at inhibere translationen af mRNA. Så resultatet må formodes at være rigelige mæmgder af alfa-2-macroglobulin.

To uafhægige proteomstudier på spinalvæske fra ME patienter har påvist opregulerede niveauer af alfa-2-macroglobulin (2,3).

Referencer:

  1. Vega et al: Epigenetic modifications and glucocorticoid sensitivity in ME/CFS. BMC Medical Genomics, 2017, 10, 11
  2. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue
  3. Baraniuk et al: CFS-related proteome in human CSF. BMC Neurology 2005, 5, 22.

fredag den 29. december 2017

Liver metabolism, GRAMD1A and ME

Germain et al found disturbances in fatty acid and lipid metablism in ME patients. The results were suggestive to damage to liver / a deficiency in liver activity (1).

de Vega et al showed that the most hypermethylated gene associated with quality of life in ME patients was GRAMD1A. A hypermethylated gene is often associated with supressed transcription (2).

GRAMD1A promotes the expansion of hepatocellular carcinoma stem cell and hepatocellular carcinoma growth through STAT5 (3).

If up-regulated GRAMD1A up-regulates STAT5 and induces growth in cancer cells, what do a down-regulated GRAMD1A do in ME patients? In liver cells? In lymphocytes?

STAT5 is involved in lymphocyte development and transformation. And STAT5 promotes the proliferation, survival and selfrenewal of hematopoietic stem cells (ref 21-24 in ref 3).

References:

  1. Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371
  2. Vega et al: Epigenetic modifications and glucocorticoid sensitivity in ME/CFS. BMC Medical Genomics, 2017, 10, 11
  3. Binsheng Fu et al: GRAMD1A promotes the expansion of hepatocellular carcinoma stem cell and hepatocellular carcinoma growth through STAT5. Nature Scientific Reports, 2. sept 2016.

lørdag den 18. november 2017

ME, nedsat PDH-funktion og behandlingsmulighed

I 2016 viste en stor norsk undersøgelse omfattende 200 ME patienter, at patienterne anvendte aminosyrer som brændstof. Årsagen til dette fænomen blev lokaliseret til at være nedsat funktion af pyruvat dehydrogenase (PDH). (1)

Naturen har indrettet det således, at vores metabolisme og enzymer er under nøje regulering. Hermed kan vi tilpasse os den føde, der er tilgængelig, og i tilfælde af hungersnød kan vi forbrænde vores fedtdepoter og i sidste ende vores muskelvæv for at overleve. Serum 3-methylhistidin, som er markør for endogen protein metabolisme, var signifikant øget hos de mandlige ME-patienter.

PDH kan nedreguleres af enzymerne PDH-kinase (PDK) 1, 2, 3 og 4. PDK 1, 2 og 4 var opregulerede hos de norske ME patienter.

Konsekvensen af nedreguleret PDH er kendt fra mennesker med medfødt defekt i enzymkomplekset. Patel et al (2) har samlet viden om de kliniske og biokemiske aspekter ved medført defekt i PDH. Sygdommen medfører neurologisk og neuromuskulær degeneration, og patienterne dør ofte inden de bliver voksne. Spændvidden i symptomer er meget bred. Der findes også patienter med milde symptomer alt afhængig af hvordan PDH er defekt og i hvilken grad.

Lactatniveauet hos disse patienter er meget forhøjet. Blodprøver viser laktat / pyruvat forhold på under 20. Der kan også påvises forandrede lactat / pyruvat værdier i spinalvæsken. Nogle af patienterne har fået påvist Leigh syndrom (subakut nekrotiserende encephalomyopati) ved hjernescanning. Det inkluderer læsioner i basal ganglia, thalamus og hjernestamme. Patienterne har symptomer som hypotonia, ataxia, perifer neuropati og øjenproblemer.

Øget laktatniveau hos ME patienter er beskrevet i ref 25 + 35 i ref 1. Natelson et al har vist forhøjede laktatværdier i spinalvæsken fra ME patienter (3).

Behandlingsmuligheder til patientgruppen med medfødt PDH defekt er begrænsede. Man forsøger med ketogen diæt og hæmning af PDK med en halogeneret organisk syre, dichloroacetat (DCA). Man skal være opmærksom på, at DCA er rapporteret som værende giftigt. Om DCA, se ref 12, 193, 197 og 202 i ref 2.

Behandling af ME patienter med en halogeneret organisk syre har allerede fundet sted i et lille belgisk pilotstudie - og med gunstigt resultat (4).

Ti patienter med ME/CFS diagnose blev behandlet, og fem responderede på behandlingen. Det pudsige i artiklen er forfatteren, emeritus professor i endokrinologi Frank Comhaire's reaktion på resultatet: Hvis medicinen ikke virker, så fejler patienterne nok noget andet end ME / nedsat PDH funktion. Og så blev de fem ikke responderende patienter undersøgt grundigt indtil de blev korrekt diagnosticeret.

Comhaire slutter sin artikel med et forslag til en diagnostisk test: Måling af koncentrationen af pyruvat og acetyl coenzym A i patienternes monocytter.

Referencer:

  1. Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
  2. Patel et al: The spectrum of pyruvate dehydrogenase deficiency. Mol Genet Metab, 2012, 105, 1.
  3. Natelson et al. Multimodal and simultaneous assesment of brain and spinal fluid abnormalities in CFS. J. Neuro Sci 2017, 375
  4. Comhaire. A novel nutriceutical treatment of ME/CFS. Intern Med 2017, 7, 5.

søndag den 1. oktober 2017

Klonal T-celle ekspansion i ME

Mark Davis fra Stanford Universitet har fundet klonal T-celle ekspansion hos ME patienter.

T-celler, også kaldet T-lymfocytter, er celler i immunforsvaret. En klon er en cellefamilie, hvor alle celler har identiske egenskaber, fordi de er masseproduceret ud fra én celle. Når man bliver angrebet af et virus, kan immunforsvaret producere massevis af ens T-celler. Disse ens T-celler er specielt indrettet til at genkende og bekæmpe netop dette virus. Dette fænomen kaldes klonal T-celle ekspansion.

Klonal T-celle ekspansion kan uheldigvis også forekomme i autoimmune sygdomme, hvor T-celle klonen retter sit angreb mod et protein fra kroppens eget væv. En T-celle klon kan samtidig være rettet mod både et virus og et protein fra kroppen, som til forveksling ligner viruset. Så skal behandling være rettet mod både virus og autoimmunitet.

Mark Davis' laboratorium vil nu forsøge at finde ud af, hvad T-celle klonen hos ME patienter har som mål. Arbejds-hypotesen ved Stanford Universitet er, at ME er en autoimmun sygdom.

lørdag den 27. maj 2017

BACH2, PRDM1, PRDM2, ELL2 and ME

BACH2, PRDM1, PRDM2 and ELL2 are epigenetic changed in ME patients (1).

  • Bach2 is a transcription factor, essential for B-cells.
  • PRDM1 encodes Blimp-1, the master regulator of plasma cells.
  • PRDM2 act as a transcriptional activator of the heme-oxygenase-1 gene.
  • Transcription elongation factor ELL2 drives Ig secretory specific mRNA production (2,3)
Heme regulates B-cell differentiation, antibody class switch and hemeoxygenase-1 expression in B cells as a ligand of Bach2 (2).

Heme inhibits Bach2.

Bach2 inhibits Blimp-1.

Blimp-1 activates ELL2.

Ig classes are dysregulated in some ME patients (4).

Some ME patients have reduced representation of pathways for heme biosynthesis (5).

References:
  1. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
  2. Watanabe-Matsu et al: B-cell differentiation, antibody class switch and hemeoxygenase-1 expression in B cells as a ligand of Bach2. Blood 19.may2011, vol117, No.20.
  3. Minnich et al: Multifunctional role of the transcription factor Blimp-1 in coordinating plasma cell differentiation. Nat Immun 17, 2016
  4. FollowMEinDenmark "Immunological findings" 17.august 2013.
  5. Nagy-Szakal et al: Fecal metagenomic profiles in subgroups of patients with ME/CFS. Microbiome 2017,5,44.

mandag den 24. april 2017

COG3, LPAAT3, ERGIC and ME

What is going on in the endoplasmic reticulum (ER) and the golgi complex in ME patients?

The gene COG3, component of oligomeric golgi complex 3, is hypomethylated in ME patients (1). The COG is required for normal golgi morphology and localization. Defects in the COG complex result in multiple deficiencies in protein glycosylation (2).

Some ME patients have SNP in the gene AGPAT3, also known as LPAAT3, lysophosphatidic acid acyltransferase 3 (3). LPAAT3 regulates golgi complex structure and function (4).

The gene ERGIC1, ER-golgi intermediate compartment 1, is hypermethylated (5). ERGIC1 is a cycling membrane protein which interacts with other members of this protein family to increase their turnover (2).

The ERGIC53 precursor is up-regulated in the cerebrospinal fluid, CFS:9 and normal value:1 (6). ERGIC53 is also known as LMAN1, lectin mannose binding 1. The protein cycles between ER and golgi, functioning as a cargo receptor for glycoprotein transport (2). LPAAT3 affects the recycling of ERGIC53 (4).

Ceramides are downregulated in the plasma from ME patients (7). The spingosine backbone from short chain ceramides is used (recycled) to make long chain ceramides. This process takes place in the golgi complex. The mycotoxin brefeldin A is used in golgi research, because it causes disassembly of the golgi complex. Research has shown that the salvage of the sphingosine backbone of short-chain ceramide to form long-chain ceramide was attenuated by brefeldin A (8).

There are many more ER/golgi genes and proteins, which are changed in ME patients compared to normal controls in references 5 and 6. Are the changes involved in cause or consequence of the ME pathomechanism?

References:

  1. Brenu et al: Methylation profile of CD4+ T cells in CFS/ME. J. Clin Cell Immunol 5, 228
  2. www.ncbi.nlm.nih.gov/gene
  3. Schlauch et al: Genome-wide association analysis identifies genetic variations in subjects with ME/CTS. 2016.doi.10.1038/tp.2015.208
  4. Schmidt and Brown: Lysophosphatic acid acyltransferase 3 regulates golgi complex structure and function. J. Cell Biol. Vol. 186, No2, 2009
  5. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
  6. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue
  7. Naviaux et al: Metabolic features of CFS. www.pnas.org/cgi/doi/10.1073/pnas.1607571113
  8. Kitatani: The sphingolipid salvage pathway inceramide metabolism and signaling. Cell Signal 2008 Jun 20, 6.



    søndag den 2. april 2017

    Choline, ME og POTS

    Choline ( dansk: kolin) er et næringsstof, som vi indtager gennem kosten. Choline er byggesten for:
    • phosphatidylcholine, som er et lipid i cellemembranen
    • neurotransmitteren acetylcholine
    • betaine, som er methylgruppe-donor og en vigtig osmolyt

    Opdagelse af choline

    Tre typer transportproteiner sørger for optagelse af choline:
    • organic cation transporters
    • high affinity choline transporters, som er tæt associeret med syntese af acetylcholine i neuronerne
    • solute carriers, SLC44A1, SLC44A2 og SLC44A3

    Syntese af phosphatidylcholine

    Choline omdannes til phosphatidylcholine (PC) via tre enzymer i tre trin, som hedder CDP-choline eller Kennedy stivejen:
    • choline omdannes til phospho-choline af choline kinase
    • phospho-choline omdannes til cytidinediphosphocholine (CDP-choline) af phosphocholinecytidyltransferase (PCYT1A)
    • CDP-choline omdannes til PC af cholinephosphotransferase (1)

    ME forskning

    Følgende gener er fundet epigenetisk ændrede hos ME patienter (2,3):
    • PCYT1A, hypomethyleret
    • SLC44A1, hypermethyleret
    • SLC44A2, hypermethyleret
    • SLC44A3, hypermethyleret
    Metaboliterne CDP-choline og choline phosphate(1-) er fundet nedregulerede i plasma fra ME-patienter (4).

    POTS forskning

    Undersøgelse af celler fra en enkelt POTS-patient viste, at patienten havde nedsat mRNA ekspression af SLC44A1 og choline optagelsen var reduceret med 60%. Lipidsammensætning i lipid rafts var ændret, hvilket påvirkede membran-permabilitet og funktion. Samtidig blev der påvist mitokondrie dysfunktion (5).

    Referencer:
    1. Fagone og Jackowski: Phosphatidylcholine and the CDP-Choline Cycle. Biochim Biophys Acto. 2013 March, 1831, 3, 523-532.
    2. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
    3. Vega et al: Epigenetic modifications and glucocorticoid sensitivity in ME/CFS. BMC Medical Genomics, 2017, 10, 11
    4. Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371
    5. Schenkel et al: Mechanism of choline deficiency and membrane alteration in POTS primary skin fibroblasts. FASEB Journal, April 2015, Vol 29.

    søndag den 12. marts 2017

    Galdesyrer, tarmflora og ME

    Basisviden

    Galdesyrer har antimikrobielle egenskaber og påvirker sammensætningen af tarmfloraen.

    Nedsat niveau af galdesyrer i tarmen favoriserer gramnegative bakterier, som kan producere giftig lipopolysakkarid (LPS). Øget niveau af galdesyrer favoriserer grampositive Firmicutes, hvilket anses for at være gunstigt for helbredet.

    Infektion af Clostridium difficile er svær at behandle. Forskere ser på muligheden for at behandle med Clostridium scindens, som kan omsætte primære galdesyrer til sekundære galdesyrer i tarmen. Den sekundære galdesyre deoxycholic acid har stor antimikrobiel effekt og beskytter mod Clostridium difficile infektion. (1)

    ME Forskning

    ME patienter har reduceret niveau af galdesyrer (se blogindlæg af 19 feb 2017).

    ME patienter har reduceret niveau af Firmicutes i tarmfloraen, og signifikant højt plasmaniveau af LPS (2)

    Det kunne være interessant med et studie, der undersøgte sammenhængen mellem galdesyreniveau og tarmflora hos ME patienter.

    Referencer:
    1. Fiorucci og Distrutti. Trends in Mol. Med. Nov 2015, 21:11
    2. Giloteaux et al. Microbiome, 2016, 4:30

    søndag den 19. februar 2017

    Kolesterol og galdesyrer i ME

    Basisviden

    Kolesterol indgår i cellens membran og påvirker cellesignalering. Kolesterol-molekylet er "byggesten" for en del hormoner, D-vitamin og galdesyrer. Kroppen tilføres kolesterol gennem maden, og resten af det kolesterol man skal bruge dannes i leveren. Ordet kolesterol kommer af det græske chole = galde og stear = fedt.

    Galdesyrer dannes i leveren, som de primære galdesyrer:
    • cholic acid (CA), dansk: kolsyre
    • chenodeoxycholic acid (CDCA), dansk: kenodeoxykolsyre
    De primære galdesyrer omsættes i tarmen af tarmbakterier til sekundære galdesyrer:
    • deoxycholic acid (DCA)
    • lithocholic acid (LCA).
    Galdesalte er natrium og kalium salte af galdesyrer konjugeret (=bundet) med glycine og taurin.

    Galdesyrer søger for, at vi kan opløse og optage det fedt vi spiser, og at vi kan optage de fedtopløselige vitaminer A, D, E og K.

    ME forskning

    Naviaux's undersøgelse af ME patienters metabolisme viste, at de biokemiske stiveje, der sørger for syntese af kolesterol og galdesyrer var dysregulerede. En metabolit i stivejene, lathosterol, var reduceret i blodet hos både mænd og kvinder i Kolesterolniveauet var normalt. Kvinderne havde nedsat niveau af galdesyren CDCA (1).

    Germain's undersøgelse af kvindelige ME patienters metabolisme viste nedregulering af følgende metabollitter (2):
    • glycocholate
    • glycochenodeoxycholate
    • glycolithocholate
    • lithocholate
    • sulfoglycolithocholate
    • taurine
    Vegas's epigenetiske studier af ME patienter afspejler en påvirkning af kolesterol/galdesyrer omsætning, idet følgende gener var epigenetiske ændrede (hypermethylerede) (3):
    • SLC10A1, transportprotein fra familien af natrium/galdesyre cotransportere.
    • OSTalpha, organic solute transporter, ligeledes et transport protein. Det er involveret i det enterohepatiske kredsløb.
    • ABCC1, transportprotein med flere funktioner, bl.a. transport af glukuronider og sulfat konjugater af steroid hormoner og galdesalte.
    • OSBPL10, oxysterol-binding protein familien er intracellulære lipid receptorer, der påvirker lipid ligevægten i cellen.
    • NPC1, Nieman -Pick C1 protein, involveret i kolesterol transport inde i cellen.
    • RAB11FIP1, RAB11 family interacting protein, involveret i kolesteroltransport inde i cellen, samtidig påvirker kolesterol lipidendocytose gennem RAB11.
    • RABGAP1, RAB GTPase activating protein, stikord til RAB GTPaser er noget med lipider, phospholiper og membrantransport gennem endo- og exocytiske stiveje.
    • CYB5R2, er involveret i kolesterol syntese, fedtsyre desaturation og elongation. CYB5R2 findes på kromosom 11, lige ved siden af genet PPFIBP2 (også hypermethyleret hos ME patienter). Det er en beta liprin, der er involveret i axon guidance og dannelse af synapser.
    Det er oplagt, at dysregulerede kolesterol/galdesyrer stiveje kan forklare irritabel tarm, især ved store fedtrige måltider. Men kan dysreguleringerne i ME patienters metabolisme også påvirke de kolesterolholdige lipid rafts i cellemembranerne og herigennem cellesignalering?
    Referencer:

    1. Naviaux et al: Metabolic features of CFS. www.pnas.org/cgi/doi/10.1073/pnas.1607571113
    2. Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371
    3. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
    Kolesterolviden: Ikonen: Cellular cholesterol trafficking and compartmentalization. Nature Reviews, 9, Feb(2008).
    Basisviden om gener: www.ncbi.nlm.nih.gov/gene

    torsdag den 9. februar 2017

    Phosphoinositides and ME

    Germain et al:

    "Another hypothesis that could be drawn from the pathway analysis concerns the glycerophospholipid metabolism, as we observed five altered metabolites involved in biological membrane composition. Phosphoinositides are phospholipids that play critical roles in the brain and the spinal cord and peripheral nerves, by being involved in cell regulation and membrane dynamics."

    I believe this hypothesis is true and very important.

    Phosphoinositides (PIs) are generated in the PI-cycle. The first step in the PI-cycle is the conversion of diacylglycerol (DAG) to phosphatidic acid (PA) via the enzyme diacylglycerol kinase (DGK).

    The last step is genration of PIP2. PIP2 is involved in cell signaling, fx regulation of TRPs.

    Glycerol-3-phosphate can be converted to lysophosphatidic acid, which can be converted to PA. Lipin (gene: LPIN) can convert PA to DAG.

    Epigenetic changed genes in ME:

    • DGKA (DGK-alpha) hypomethylated (2)
    • DGKQ (DGK-theta) hypermethylated, with a negative foldchange (3)
    • LPIN1 hypermethylated (2)
    References:


      1. Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371
      2. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
      3. Brenu et al: Methylation profile of CD4+ T cells in CFS/ME. J. Clin Cell Immunol 5, 228

      GPD2, the glycerophosphate-shuttle and ME

      Glucose/pyruvate and lipid metabolism have been found dysregulated in ME (1, 2, 3)

      Glycero-3-phosphate has been found up-regulated in ME (3).

      The gene GPD2 codes mithochondrial glycerol-3-phosphate dehydrogenase (mGPDH).

      mGPDH oxidizes glycerol-3-phosphate to dihydroxyacetone phosphate.

      mGPDH is a very important enzyme of intermediary metabolism and as a component of glycerophosphate shuttle at the crossroads of glycolysis, oxidative phosphorylation and fatty acid metabolism (4).

      These genes have been found epigenetic changed (hypermethylated) in ME (5):

      • GPD2, glycerol-3-phosphate dehydrogenase 2
      • SLC37A3, solute carrier family 37, glycerol-3-phosphate transporter
      • DAK, dihydroxyacetone kinase 2 homolog
      References:

      1. Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
      2. Naviaux et al: Metabolic features of CFS. www.pnas.org/cgi/doi/10.1073/pnas.1607571113
      3. Germain et al: Metabolic profiling of a ME/CFS discovery cohort reveals disturbances in fatty acid and lipid metabolism. Mol. BioSyst. 2017, 13, 371
      4. Mracek et al: The function and the role of the mitochondrial glycerol-3-phosphate dehydrogenase in mammalian tissue. Biochimica et Biophysica Acta 1827, 2013, 401-410.
      5. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757

      onsdag den 1. februar 2017

      IDH, GOT and ME

      Fluge, Mella et al. have shown that ME is associated with defective oxidative metabolism - most likely involving impaired pyruvate dehydrogenase (PDH) function (1).

      A study showed that PDH suppression shifted the source of lipogenic acetyl-CoA from glucose to glutamine, and this compensatory pathway required a net reductive isocitrate dehydrogenase (IDH) flux to produce a source of glutamine-derived acetyl-CoA for fatty acid. Levels of intra- and extracellular aspartate and alanine were enhanced (2).

      Another study showed that inhibition of the mitochondrial pyruvate carrier in the retina caused accumulation of aspartate at the expense of glutamate. The mitochondrial glutamate oxoglutarate transaminase (GOT2) - also knowns as aspartate aminotransferase - became upregulated (3).

      Expression of IDH-proteins (IDH3A, IDH3B and IDHP) and of GOT2 have been found upregulated in ME (4).

      A proteomic study on cerebrospinal fluid from ME/CFS patients has shown (5):

      • IDH1, CFS:2, normal value 4
      • GOT1, CFS:39, normal value 29
      • GOT2, CFS:1, normal value 6
      Armstrong et al have shown increased aspartate, decreased glutamate and a potentially reduced provision of acetyl-CoA for the TCA-cycle (6).

      Glutamate is important as a neurotransmitter and as a substrate for glutathione synthesis. Depletion of glutamate correlates with cell death in the retina (3).

      Shungu et al. have found elevated ventricular lactate and decreased glutathione in CFS patients (7).

      I have noticed that some ME patients develop an early age-related degeneration of the retina. Could dysregulated metabolism be involved?

      The aspartate aminotransferase blood test (ASAT) is usually normal in ME patients. Could there be a local tissue-specific dysregulayion?

      If glutamate decreases, what happens to the glutamate-NO-cGMP pathway in the brain?

      References:

      1. Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
      2. Rajagopalan et al. Metabolic plasticity maintains proliferation in pyruvate dehydrogenase deficient cells. Cancer & Metabolism (2015) 3:7
      3. Du et al. Inhibition of mitochondrial pyruvate transport by Zaprinast couses massive accumulation of aspartate at the expence of glutamate in the retina. Journal of Biological Chemistry 288,50,dec 2013
      4. Ciregia et al.
        Translational Psychiatry (2016), 6, e904
        doi:10.1038/tp.2016.184
      5. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue 2
      6. Armstrong et al. Metabolic profiling reveals anomalous energy metabolism and oxidative stress pathways in CFS. Metabolomics, 2015, 11:1626-1639.
      7. Dikoma C Shungu et al. Increased Ventricular lactate in chronic fatigue syndrome. III. Relationships to cortical glutathione and clinical symptoms implicate oxidative stress in disorder oathophysiology. NMR Biomed (2012)

      søndag den 29. januar 2017

      nAChR, agrin, rapsyn and ME

      Nicotinic acatylcholine receptors (nAChRs) are suspected to be involved in the ME pathomechanism (1).

      ME patients have dysregulated lipid metabolism (2). This could have an impact on lipid rafts?

      Lipid rafts serve as signaling platforms for nAChRs clustering. The clustering is induced by the heparan sulphate proteoglyan, agrin. The nAChRs are anchored into the lipid rafts by rapsyn (3).

      A proteomic study on cerebrospinal fluid from ME patients has shown an upregulation of the arin precursor and of the heparan sulfate proteoglyan core protein precursor (4).

      The gene RAPSN (protein: rapsyn) has been found epigenetic changed (hypermethylated) in ME (5).

      References:
      1. Griffith University. https://www.griffith.edu.au/health/national-centre-neuroimmunology-emerging-diseases
      2. Naviaux et al: Metabolic features of CFS. www.pnas.org/cgi/doi/10.1073/pnas.1607571113
      3. Allen et al: Lipid raft microdomains and neurotransmitter signalling. Nature Reviews, feb 2007, vol 8.
      4. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue 
      5. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757

      fredag den 27. januar 2017

      Sidder sjælen i blodet?

      I Danmark kaldes Myalgisk Encephalomyelitis / Chronic Fatigue Syndrome ME/CFS) for en funktionel lidelse, som beskrives som en sygdom mellem krop og sjæl. Der anbefales intens behandling med kognitiv terapi, hvilket må formodes at være rettet mod sjælen (1).

      I Norge er kræftlægerne Fluge og Mella i færd med at gennemføre et Rituximab – fase III – studie til behandling af ME/CFS (2).

      Nu er Fluge, Mella og deres forsker-team aktuelle med et nyt studie, hvor der deltog 200 ME/CFS patienter og 102 raske kontrolpersoner. Analyse af ME/CFS patienternes metabolisme viste:
      • En reduktion af aminosyrer, der anvendes til oxidativ metabolisme via trikarboxylsyrecyklus. Dette sås hovedsagelig hos de kvindelige patienter.
      • Serum 3-metylhistidin, som er markør for endogen protein katabolisme, var signifikant øget hos mænd.
      • En aminosyrer omsætning, der tydede på nedsat pyruvat dehydrogenase funktion.
      • Øget mRNA ekspression af de inhibitoriske pyruvat dehydrogenase kinaser (PDK) 1, 2 og 4; sirtuin 4 og PPAR-delta. Dette fund forekom hos både mænd og kvinder.
      • mRNA ekspression af PDK1 korrelerede med sygdomsgrad.
      • Muskelceller in vitro der blev tilført serum fra ME/CFS patienter udviklede metaboliske tilpasninger i form af øget mitokondriel respiration og forhøjet laktat produktion ved forskellige test, der simulerede muskelbelastning. Dvs et respons der er i overenstemmelse med det kliniske sygdomsbillede af ME/CFS med utilstrækkelig ATP dannelse ved oxidativ fosforylering og forøget laktat dannelse ved belastning (3).


      Det er ganske interessant, at blod fra ME/CFS patienter kan ændre metabolismen i muskelceller i et reagensglas. Det får mig til at stille spørgsmålet: ”Sidder sjælen i blodet?”

      Mediedækning af forskningen:

      Fluge og Mellas ME-forskning var i Norges TV2 nyheder d. 4/1.
      https://www.youtube.com/watch?v=ZvWFwj-N9dk  (3.36 min)

      Der var også et indslag i norsk TV2 d. 5/1 med Fag-direktør Per Magnus fra Folkehelse-instituttet.
      https://www.youtube.com/watch?v=XYziEAz3FSk (1.19 min)

      Og Hanne Thurmer, en af forskerne bag Rituximab-studiet, var i norsk radio på NRK Telemark d. 5/1.
      https://radio.nrk.no/serie/distriktsprogram-telemark/DKTE02000417/05-01-2017#t=1h5m54s

      Jyllandsposten.
      http://jyllands-posten.dk/international/europa/ECE9278647/nordmand-i-hi-paa-11-aar-har-aldrig-set-en-iphone-eller-facebook/

      Referencer:
      1. Funktionel lidelser. Klinisk Vejledning for almen praksis. Dansk Selskab for Almen Medicin, 2013
      2. ”B-lymphocyte depletion using rituximab in chronic fatigue syndrome/myalgic encephalopathy (CFS/ME). A randomized phase-III study. (RituxME)” Clinical Trials.gov Identifier: NCT02229942 https://clinicaltrials.gov/ct2/NCT02229942
      3. Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276


      søndag den 22. januar 2017

      Pyruvate and ME/POTS

      Fluge, Mella et al. have shown that ME is associated with defective oxidative metabolism - most likely involving impaired pyruvate dehydrogenase function (1).

      Expression of the protein mitochondrial pyruvate carrier 2 (MCC2) has been found downregulated in ME (2)

      The gene similar to pyruvate kinase-isozymes M1/M2 (PKM2) has been found epigenetic changed (hypermethylated) in ME (3).

      Immunoreactive proteins against IgGs from POTS patients (4, 5):

      • ODPB, pyruvate dehydrogenase E1 component subunit beta.
      • KPYM, pyruvate kinase isoenzyme M1.
      • PDHX, pyruvate dehydrogenase protein X component.
      • PKM2, pyruvate kinase isozymes M1/M2
      References:

      1.  Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
      2. Ciregia et al.
        Translational Psychiatry (2016), 6, e904
        doi:10.1038/tp.2016.184
      3. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
      4. Wang et al: Autoimmunoreactive IgGs from patients with POTS. Prot. Clin. Appl. 2012, 6, 1-11.
      5. Wang et al: Autoimmunoreactive IgGs against cardiac lipid raft-associated proteins in patients with POTS. doi: 10.1016/j.trsl.2013.03.002

      lørdag den 21. januar 2017

      ALDH4A1 and ME

      Delta-1-pyrroline-5-carboxylate dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH4A1 gene (aldehyde dehydrogenase 4 family, member A1). This enzyme is a mitochondrial matrix NAD-dependent dehydrogenase that catalyzes the second step of the proline degradation pathway, converting pyrroline-5-carboxylate to glutamate. Deficiency of this enzyme is associated with type II hyperprolinemia, an autosomal recessive disorder characterized by accumulation of delta-1-pyrroline-5-carboxylate (P5C) and proline. (1).

      Pyrroline-5-carboxylic acid is increased in ME patients (2).

      The gene ALDH4A1 has been found epigenetic changed (hypermethylated) in ME (3).

      Expression of the proteins P5C-dehyrogenase and P5C-synthase have been found upregulated in ME (4).

      P5C-dehydrogenase has been found to be an immunoreactive protein against IgGs from POTS-patients (5).

      References:

      1. Wikipedia: Aldehyde dehydrogenase 4 family, member A1
      2. Naviaux et al: Metabolic features of CFS. www.pnas.org/cgi/doi/10.1073/pnas.1607571113
      3. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e10475
      4. Ciregia et al.
        Translational Psychiatry (2016), 6, e904
        doi:10.1038/tp.2016.184
      5. Wang et al: Autoimmunoreactive IgGs from patients with POTS. Prot. Clin. Appl. 2012, 6, 1-11.

      mandag den 16. januar 2017

      ACAD8 and ME

      Fluge, Mella et al. have shown that ME is associated with defective oxidative metabolism - most likely involving impaired pyruvate dehydrogenase function - leading to increased utilization  of ketogenic amino acids to fuel the TCA-cycle (1).

      A proteomic study on cerebrospinal fluid from ME/CFS patients has shown an upregulation of the pathway "valine, leucine and isoleucine degradation" (table S6 in ref 2).

      The gene acyl-CoA.dehydrogenase family member 8 (ACAD8) has been found epigenetic changed (hypermethylated) in ME (3).

      ACAD8 is an isobutyryl-CoA dehydrogenase that functions in the catabolism of branched-chain amino acids including valine, and shows high reactivity toward isobutyryl-CoA. ACAD8 is responsible for the third step in the breakdown of valine and converts isobutyryl-CoA into methylacrylyl-CoA.

      References:
      1. Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
      2. Schutzer et al: Distinct Cerebrospinal Fluid Proteomes Differentiate Post- Treatment Lyme Disease from Chronic Fatigue Syndrome. PLOS One February 2011, volume 6, Issue 2
      3. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757
      4. Wikipedia: ACAD8

      søndag den 15. januar 2017

      HMGCL and ME

      Fluge, Mella et al. have shown that ME is associated with defective oxidative metabolism - most likely involving impaired pyruvate dehydrogenase function - leading to increased utilization  of ketogenic amino acids (1).

      Hydroxymethyl - methylglutaryl - CoA-lyase (HMGCL) is a key enzyme in ketone body formation.

      Expression of the protein HMGCL has been found upregulated in ME (2).

      The gene HMGCL has been found epigenetic changed (hypermethylated) in ME (3).

      Reference:

      1.  Fluge et al: Metabolic profiling indicates impaired pyruvate dehydrogenase function in myalgic encephalopathy / chronic fatigue syndrome. JCI Insight. 2016; 1(21):e89376. Doi 10.1172/jci.insight.89276
      2. Ciregia et al.
        Translational Psychiatry (2016), 6, e904
        doi:10.1038/tp.2016.184
      3. Vega et al. DNA methylation Modifications associated with CFS. Plos One, aug 2014, vol 9, Issue 8, e104757