Difference between revisions of "Pesta 2011Abstract Mitochondrial Medicine-Diagnosis"

Latest revision as of 18:17, 10 January 2022

Pesta D, Wiethuechter A, Karall D, Schocke M, Gnaiger E (2011) Functional mitochondrial diagnosis in a patient suffering from sudden exercise intolerance. Abstract Mitochondrial Medicine Chicago.

Link: UMDF 2011

Pesta D, Wiethuechter A, Karall D, Schocke M, Gnaiger E (2011)

Event: Mitochondrial Medicine Chicago

A 28-year-old former amateur cyclist demonstrated a sudden exercise intolerance and impairment in muscle function since March 2008 without clinical explanation. The main symptom was a decreased ergometric aerobic capacity by 50%. A specific defect of mitochondrial glutamate dehydrogenase (GDH) was indicated by lack of ADP stimulation in the presence of glutamate and subsequent rescue of respiration after addition of malate.

• Keywords: Glutamate dehydrogenase

• O2k-Network Lab: AT Innsbruck Oroboros, AT Innsbruck Burtscher M

Full abstract

A 28-year-old former amateur cyclist demonstrated a sudden exercise intolerance and impairment in muscle function since March 2008 without clinical explanation. The main symptom was a decreased ergometric aerobic capacity by 50%.

A small needle biopsy sample was obtained from the patient´s M. vastus lateralis to assess mitochondrial function by high-resolution respirometry using substrate-uncoupler-inhibitor titration (SUIT) protocols on permeabilized fibers [1,2]. The patient performed an in-vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) test of the quadriceps muscles during dynamic leg-extension exercise [3] and a pelvic-leg angiography (0.2 mL/kg Multihance, Bracco, Italy). Additional metabolic investigations were performed on blood, blood gas and urine smaples.

A specific defect of mitochondrial glutamate dehydrogenase (GDH) was indicated by lack of ADP stimulation in the presence of glutamate and subsequent rescue of respiration after addition of malate. Except for a low CI/CII flux ratio, mass-specific respirometric fluxes were low but generally comparable to healthy controls, explaining a decreased exercise capacity but not the diseased condition of the patient. Phosphorylation capacity was apparently normal as indicated by an unsuspicious PCr recovery time (t=40 s). This is in line with a P/E ratio of ~0.9 and normal coupling control of mitochondrial respiration. Although the angiography did not indicate any stenosis in the common iliac arteries, an atypical initial increase from c. 4 to 10 mM was observed in inorganic phosphate (Pi) during mild exercise performed with an MR-suitable ergometer. Metabolic investigations were normal (acylcarnitine profile, amino acid in plasma and urine, organic acids in urine, lactate, glucose, blood gas analysis and creatine kinase as well as liver function tests).

Our data indicate a reduced Pi-buffering capacity in the muscle resulting in accumulation of Pi from baseline to c. 10 mM. Whereas the phosphorylation system and pyruvate-supported respiration were unimpaired, we found a specific defect of mitochondrial GDH and a low CI/CII flux ratio. Taken together, these data may explain the exercise intolerance in the patient, with clinical symptoms possibly delayed by a physically active life style.

Supported by OeNB Jubilaeumsfond Austria, project 13476; contribution to Mitofood COST Action FAO602, and MitoCom_O2k-Fluorometer Network Tyrol.

Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int J Biochem Cell Biol 41:1837–45.
Pesta D, Gnaiger E (2012) High-resolution respirometry. OXPHOS protocols for human cells and permeabilized fibres from small biopsies of human muscle. Methods Mol Biol 810:25-58.
Schocke MF, Esterhammer R, Arnold W, Kammerlander C, Burtscher M, Fraedrich G, et al (2005) High-energy phosphate metabolism during two bouts of progressive calf exercise in humans measured by phosphorus-31 magnetic resonance spectroscopy. Eur J Appl Physiol 93:469-79.

Labels:

Stress:Mitochondrial disease Organism: Human

Preparation: Permeabilized tissue, Homogenate Enzyme: TCA cycle and matrix dehydrogenases

Coupling state: OXPHOS

HRR: Oxygraph-2k

@@ Line 1: / Line 1: @@
-{{Publication
+{{Abstract
-|title=Pesta D, Hoppel F, Macek C, Messner H, Faulhaber M, Kobel C, Parson W, Burtscher M, Schocke M, Gnaiger E (2011) Mitochondrial improvements after strength, endurance, and intermittend hypoxic training in sedentary humans. A respiratory study on permeabilized muscle fibres. Abstract Mitochondrial Medicine Chicago.
+|title=Pesta D, Wiethuechter A, Karall D, Schocke M, Gnaiger E (2011) Functional mitochondrial diagnosis in a patient suffering from sudden exercise intolerance. Abstract Mitochondrial Medicine Chicago.
 |info=[http://www.umdf.org/symposium UMDF 2011]
-|authors=Pesta D, Hoppel F, Macek C, Messner H, Faulhaber M, Kobel C, Parson W, Burtscher M, Schocke M, Gnaiger E
+|authors=Pesta D, Wiethuechter A, Karall D, Schocke M, Gnaiger E
 |year=2011
+|event=Mitochondrial Medicine Chicago
+|abstract=A 28-year-old former amateur cyclist demonstrated a sudden exercise intolerance and impairment in muscle function since March 2008 without clinical explanation. The main symptom was a decreased ergometric aerobic capacity by 50%. A specific defect of mitochondrial glutamate dehydrogenase (GDH) was indicated by lack of ADP stimulation in the presence of glutamate and subsequent rescue of respiration after addition of malate.
+|keywords=Glutamate dehydrogenase
+|mipnetlab=AT Innsbruck Oroboros, AT Innsbruck Burtscher M
 |journal=Abstract
-|abstract=The main finding was a significant increase (''P''<0.05) of lipid oxidation capacity in all groups, after normoxic (255% ETN, ''N''=8 and 238% STN, ''N''=3), and hypoxic endurance and strength training (198% ET, ''N''=7 and 198% ST, ''N''=7).
-|mipnetlab=AT Innsbruck Gnaiger E, AT Innsbruck Burtscher M
-}}
-{{Labeling
-|instruments=Oxygraph-2k
-|injuries=Hypoxia
-|organism=Human
-|tissues=Skeletal Muscle
-|preparations=Permeabilized Cell or Tissue; Homogenate
-|topics=Respiration; OXPHOS; ETS Capacity, Mitochondrial Biogenesis; Mitochondrial Density
-|additional=Training
 }}
 ==Full abstract==
-Endurance and strength training are established as two distinct training modalities, increasing either mitochondrial density or extension of myofibrillar units. Recent research, however, suggests that mitochondrial biogenesis can be induced by both strength and conventional endurance training.
+A 28-year-old former amateur cyclist demonstrated a sudden exercise intolerance and impairment in muscle function since March 2008 without clinical explanation. The main symptom was a decreased ergometric aerobic capacity by 50%.
-In order to test the training-specific hypothesis, mitochondrial respiratory function was studied by high-resolution respirometry in response to a 10-weeks training program using human permeablized muscle fibers from 26 sedentary volunteers undergoing either endurance or strength training in normoxia (ETN, STN; FiO2=21%) or hypoxia (ETH, STH; FiO2=13.5%). Biopsies were taken from the m. vastus lateralis and all volunteers performed a cycle-ergometric incremental exercise test under normoxia to determine their ''V''O2,max before and after training.
+A small needle biopsy sample was obtained from the patient´s M. vastus lateralis to assess mitochondrial function by high-resolution respirometry using substrate-uncoupler-inhibitor titration ([[SUIT]]) protocols on permeabilized fibers [1,2]. The patient performed an in-vivo phosphorus-31 magnetic resonance spectroscopy (31P MRS) test of the quadriceps muscles during dynamic leg-extension exercise [3] and a pelvic-leg angiography (0.2 mL/kg Multihance, Bracco, Italy). Additional metabolic investigations were performed on blood, blood gas and urine smaples.
-The main finding was a significant increase (''P''<0.05) of lipid oxidation capacity in all groups, after normoxic (255% ETN, ''N''=8 and 238% STN, ''N''=3), and hypoxic endurance and strength training (198% ET, ''N''=7 and 198% ST, ''N''=7). This increase was related mainly to a change in mitochondrial density, reflected by the tissue-specific respiratory capacity with [[Complex I]]- and [[Complex II]]-related substrates. Although this index of mitochondrial density increased significantly in the ETN group only (''P''<0.05), the trend was identical in all groups, without significant increases in mtDNA contents. Qualitative mitochondrial changes, however, were significant (''P''<0.01) in all training regimes, indicated by the increased relative capacity for lipid oxidation and increased coupling of oxidative phosphorylation.
+A specific defect of mitochondrial glutamate dehydrogenase (GDH) was indicated by lack of ADP stimulation in the presence of glutamate and subsequent rescue of respiration after addition of malate. Except for a low CI/CII flux ratio, mass-specific respirometric fluxes were low but generally comparable to healthy controls, explaining a decreased exercise capacity but not the diseased condition of the patient. Phosphorylation capacity was apparently normal as indicated by an unsuspicious PCr recovery time (''t''=40 s). This is in line with a ''[[P/E]]'' ratio of ~0.9 and normal coupling control of mitochondrial respiration. Although the angiography did not indicate any stenosis in the common iliac arteries, an atypical initial increase from c. 4 to 10 mM was observed in inorganic phosphate (Pi) during mild exercise performed with an MR-suitable ergometer. Metabolic investigations were normal (acylcarnitine profile, amino acid in plasma and urine, organic acids in urine, lactate, glucose, blood gas analysis and creatine kinase as well as liver function tests).
-Exercise training leads to several alterations of mitochondrial function regardless of normoxic or hypoxic exposure. Unexpectedly, key mitochondrial adaptations were similar in the endurance and strength training group, which reflects a different response to training in sedentary versus athletic subjects. Beyond these novel results on specific training regimes, the present study on sports science establishes a data base on healthy but sedentary subjects, as valuable controls for evaluation of functional mitochondrial defects in patients.
+Our data indicate a reduced Pi-buffering capacity in the muscle resulting in accumulation of Pi from baseline to c. 10 mM. Whereas the phosphorylation system and pyruvate-supported respiration were unimpaired, we found a specific defect of mitochondrial GDH and a low CI/CII flux ratio. Taken together, these data may explain the exercise intolerance in the patient, with clinical symptoms possibly delayed by a physically active life style.
-Supported by OeNB Jubilaeumsfond Austria, project 13476. Contribution to ''[[MitoCom]] Network Tyrol''.
+Supported by OeNB Jubilaeumsfond Austria, project 13476; contribution to Mitofood COST Action FAO602, and ''[[MitoCom_O2k-Fluorometer]] Network Tyrol''.
+# [[Gnaiger 2009 Int J Biochem Cell Biol|Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int J Biochem Cell Biol 41:1837–45]].
+# [[Pesta 2012 Methods Mol. Biol.|Pesta D, Gnaiger E (2012) High-resolution respirometry. OXPHOS protocols for human cells and permeabilized fibres from small biopsies of human muscle. Methods Mol Biol 810:25-58]].
+# Schocke MF, Esterhammer R, Arnold W, Kammerlander C, Burtscher M, Fraedrich G, et al (2005) High-energy phosphate metabolism during two bouts of progressive calf exercise in humans measured by phosphorus-31 magnetic resonance spectroscopy. Eur J Appl Physiol 93:469-79.
+{{Labeling
+|organism=Human
+|preparations=Permeabilized tissue, Homogenate
+|enzymes=TCA cycle and matrix dehydrogenases
+|injuries=Mitochondrial disease
+|couplingstates=OXPHOS
+|instruments=Oxygraph-2k
+|journal=Abstract
+}}