metabolòmicadiposit.ub.edu/.../2445/96405/1/seminari3cascante.pdf · 2016-03-11 · metabolòmica...
TRANSCRIPT
Metabolòmica
Marta Cascante
Integrative Systems Biology, Metabolomics and Cancer lab
Department of Biochemistry and Molecular Biology
Institute of Biomedicine University of Barcelona (IBUB)
E-mail: [email protected] http://www.bq.ub.es/bioqint/arecerca.html
DNA
RNA
Protein
Biochemicals (Metabolites)
Genomics
Transcriptomics
Metabolomics
Proteomics Proteins
SYSTEMS BIOLOGY
Cytomics
Genomics
Proteomics
Metabolomics
Information
Highest capacity to predict phenotype
Fluxomics
FROM MOLECULAR BIOLOGY TO SYSTEMS BIOLOGY
Metabolomics and fluxomics in the
systems Biology approach
-These networks are not independent but form “network of networks“
-Metabolic network crosstalk with other networks must be considered
in a systems biology approach
Driving force: Development of high-throughput data-collection techniques,
e.g. microarrays, protein chips, NMR, LC/MS-GC/MS….
allow to simultaneously interrogate all cell components
at any given time.
From molecules to networks:
transcription/regulatory network ...
- protein-protein interaction network
- signaling network
- metabolic network
Metabolites
Metabolites are not only the “end point” also the “driving force”?
Metabolomics and fluxomics in the systems
Biology approach
Gene
mRNA
Proteines
-Biological processes
regulation is a complex
phenomena more
“democratic” than
“hierarchical”
Central dogma of molecular biology:
• Metabolomics allows direct measurement of
multiple low-molecular-weight metabolites from a
biological sample.
• Metabonomics (often named metabolomics)
The study of the systemic biochemical profiles
and regulation of function in whole organisms by
analyzing a metabolome in biofluids and tissues
• Metabolomics allows direct measurement of
multiple low-molecular-weight metabolites from a
biological sample.
• Metabonomics (often named metabolomics)
The study of the systemic biochemical profiles
and regulation of function in whole organisms by
analyzing a metabolome in biofluids and tissues
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• Metabolomics allows direct measurement of
multiple low-molecular-weight metabolites from a
biological sample.
• Metabonomics (often named metabolomics)
The study of the systemic biochemical profiles
and regulation of function in whole organisms by
analyzing a metabolome in biofluids and tissues
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• Metabolomics allows direct measurement of
multiple low-molecular-weight metabolites from a
biological sample.
• Metabonomics (often named metabolomics)
The study of the systemic biochemical profiles
and regulation of function in whole organisms by
analyzing a metabolome in biofluids and tissues
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• Metabolomics allows direct measurement of
multiple low-molecular-weight metabolites from a
biological sample.
• Metabonomics (often named metabolomics)
The study of the systemic biochemical profiles
and regulation of function in whole organisms by
analyzing a metabolome in biofluids and tissues
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• The study of the total metabolite pools (metabolome)
in a cell-organism at one particular point in time.
• Highthroughput metabolite profiling: the identification of
the specific metabolic profile that characterizes a given
sample, i.e. the set of all of the metabolites or derivative
products (identified or unknown) detected by analysing a
sample using a particular technique. Biomarkers
identification etc.....
• Target metabolomics: Selected known metabolites are
analysed: Biological question, biomedical hypothesis...
drives the analysis of a set of compounds that are related to
specific pathways.
Complementary approaches:
• Rapid sampling and fast quenching needed (much faster than the
turnover times of the metabolite pools)
• Complete extraction
• No metabolite degradation during extraction/processing/storage
• No enzymatic conversion during sample processing
Obtaining proper “snapshots” of the metabolome in time requires
Standard Operation Protocols. Validation for each experiment
necessary.
Challenges : all metabolic activity has
to be stopped in the moment of
sampling
Metabolomics experimental approaches:
-Large differences in: Physicochemical properties (polarity, hydrophobicity),
structure, concentration range…… Combination of techniques is necessary
• Enzymatic assays, HPLC, Capillary electrophoresis-mass spectrometry
(CE-MS/MS)
• Liquid chromatography-mass spectrometry (LC-MS/MS)
• Gas chromatography-mass spectrometry (GC-MS)
• NMR
Currently most used methods
The metabolome does not consist of a limited number of
building blocks…. we are far away to have a “microarray”!
Metabolome analysis:
Analytical Technologies
NMR spectroscopy Solution state (plasma, urine, extracts)
MAS (tissue extracts)
in vivo spectroscopy
Relatively robust
GC- and LC-Mass spectroscopy More analytically sensitive
Potentially truly global
Problems with ionisation
- Catalogue of all metabolites that can potentially be found in human tissues.
-Purified metabolites to be used as standards and/or spectral libraries.
-SOPs for different platforms and appropriate chemometrics tools
What is needed?
Van der Greef et al. “The Role of Metabolomics in Systems
Biology” In: Metabolic Profiling, Kluwer (2003).
Tissue or biofluid sample
Bioanalytical tools 1. Mass spectrometry
2. 1H NMR spectroscopy
Measure the
metabolite profile
e.g. by NMR
Treat profile as ‘fingerprint’ for diagnostic purposes
Statistical bioinformatic tools
Explore profile to determine mechanism and potential
biomarkers
Metabolomics: diagnostic, mechanism, biomarkers....
E.g. plasma samples randomly selected from 12 students….
10 of the profiles are very similar (“normal”)
2 abnormal profiles
- too much alcohol?
- diseased?
Use computerized pattern recognition
methods
alcoholic
diseased
normal
citrate
histidine
Insight into mechanism of disease/toxicant
E.g. plasma samples randomly selected from 12 students….
Analysis of human samples
Blood – serum or plasma
Urine
Tumour samples
Biopsies
Biomarker Discovery
Cell based model studies
Choice of cell line
Cell content or
secreted metabolites
Systems Biology Approach: - Drug target discovery
Example: applications in cancer
The Metabolome of an organism is the result of the in vivo function of gene
products and is, is closely tied to its physiology and its environment (what
is eat or breath).
• The distinct metabolic processes involved in metabolites production
and degradation are dynamic and finely regulated and
interconnected.
• Knowledge of the metaboloma is not enough to predict the phenotype
as give only an instant 'snapshot' of the physiology of that cell.
• For a characterization of metabolic networks and their functional
operation quantitative knowledge of intracellular metabolic fluxes
is required.
Fluxomics is the field of “omics” research dealing
with the dynamic changes of metabolites over time, i.e.
the quantitative analysis of fluxes through metabolic
pathways
Fluxomics
Methods
Intracellular fluxes can be estimated through:
• Knowledge of network stoichiometry
•Quantitative measurements of metabolites at different
times and/or incubation of cells/organisms with labeled
substrates (i.e. 13C)
•Interpretation of stable isotope patterns in metabolites
using appropriate software packages.
• Transcriptomics and proteomic analysis do not tell the
whole story of what might be happening in a cell.
• Metabolomics anf fluxomics offers a unique
opportunity to look at relationships between genotype
and phenotype as well as with environment.
-Metabolomics and fluxomics in cancer:
-From tumor metabolome to new therapies targeting
tumor metabolome?
Metabolomics and fluxomics in Cancer
Systems Biology
(modified from Negrini et al., 2010)
Accelerated, disordered and decontrolled proliferation of tissue cells that
invades, moves and destroys as well as in a local level as in distance, other
health tissues of the organism.
CANCER
Changes in PROTEOME
Signaling pathways, transcription
factors…
Changes in GENOME
Oncogenes and tumor supressor
genes…
Limitless replicative potential
DNA damage and DNA replication stress
Mitotic stress
Genomic instability
Metabolic stress
Evading immune surveillance
Sustained angiogenesis
Tissue invasion and metastasis Evading cell death and senescence
Activated growth signalling
TUMOR METABOLOME
Is metabolic network reorganization a consequence or a cause of tumor progression?
Could metabolism be used as therapeutic target against tumor progression?
Alterations in METABOLISM
Changes in PROTEOME
Signaling pathways, transcription
factors…
Changes in GENOME
Oncogenes and tumor supressor
genes…
CANCER
Satisfy energetic tumor requirements
Creation of acidic environment
Insensibility to O2
Decrease of pyruvate oxidation in the mitochondria
General increase of glycolytic intermediates
High glucose consumption and lactate production. Warburg effect
Activation of biosynthetic pathways
Expression of isoforms, changes in enzymatic activities and affinities
- M2-Pyruvate kinase (M2-PK)
- Transketolase-like 1 (TKTL1)
- Hexokinase I and II (HK)
Lactate
Glucose G6P
F1,6BP
DHAP
Pyr
Acetyl-CoA
CO2
Citrate
Acetyl-CoA Malonyl-CoA
Fatty acids
PEP
Pyr
1,3BPG
3PG
2PG
F6P
6PGT Ru5P
E4P
6PGL
S7P
GAP
X5P R5P
Nucleotide
synthesis
Lactate
NADPH NADPH
Palmitate
Citrate
TKTL1
M2-PK
HK II
TUMOR METABOLOME
See as a review: Robust metabolic adaptation underlying tumor progression
Vizan P, Mazurek S and Cascante M, Metabolomics (2008) 4:1–12
Cancer cells are perfect systems
to invade and parasite other tissues
Robust metabolic profile
FRAGILITY
Exploitable Target
for
CANCER THERAPY?
unexpected
perturbations
CANCER AS A METABOLIC ALTERATION
MULTIPLE HIT CANCER THERAPY AT METABOLIC LEVEL
Multiple hit strategies can avoid bypass of single inhibitions
A
B
C
D
E F
1
3
2
Parallel reactions
In series reactions
Tumor metabolism robustness counteracts single hits
Synergy
Addition
Antagonism
Tumor metabolism response to multiple inhibition is
unpredictable
Rational design of new therapeutical combinations is necessary
MULTIPLE HIT CANCER THERAPY AT METABOLIC LEVEL
Multiple hit strategies can avoid bypass of single inhibitions
A
B
C
D
E F
1
3
2
Tumor metabolism robustness counteracts single hits
Synergy
Addition
Antagonism
Tumor metabolism response to multiple inhibition is
unpredictable
Rational design of new therapeutical combinations is necessary
KNOWLEDGE
OF THE
METABOLIC NETWORK
[1,2-13C]-glucose
[2,3-13C]-pyr
[1,2-13C]-acetylCoA
Fatty acid synthesis
[5,6-13C]-citrate
[4,5-13C]--
ketoglutarate Glutamate
[2,3-13C]-OAA
[2,3-13C]--
ketoglutarate Glutamate
Pyruvate dehydrogenase Pyruvate
carboxylase
FLUXOMICS FOR THE ANALYSIS OF TUMOR METABOLOME
Metabolomics and Fluxomics are necessary for rational design of new
therapeutical combinations
TRACER-BASED METABOLOMICS
Metabolic Pathways
Metabolome
FLUXOME
AN ALGORITHM FOR DYNAMICS ANALYSIS OF THE
ISOTOPE TRACER DISTRIBUTION IN METABOLITES
Experimental tools
for Tracer-based
metabolomics permit
to obtain dynamic
data that need to be
analyzed and can be
used for fluxes
estimation
They should permit
to evaluate
metabolic fluxes
under non-steady
state in situ
conditions and to
provide insight to the
kinetic mechanisms
which govern the
metabolic networks
in vivo
EXPERIMENTAL TOOLS COMPUTATIONAL TOOLS
Able to analyze:
Data generated on different platforms (GC-LC/MS, NMR) on the metabolites levels and
isotopic isomer distributions obtained by incubation with stable labeled substrates
the non-steady state of metabolism (time courses)
By using enzyme kinetic idata in combination with in vitro or in vivo metabolomic data
ALGORITHM
Useful to:
Analyze and understand the metabolic adaptations supporting cell functions
Design metabolic interventions in drug development
Obtain dynamic data Evaluate metabolic
fluxes
METABOLIC
FLUX MAP TRACER-BASED
METABOLOMICS
Selivanov et al, 2005 Bioinformatics Selivanov et al, 2004 Bioinformatics
Selivanov et al, 2006 Bioinformatics
Glucose
G6P
F6P
GAP
Pyruvate Lactate
AcetylCoA
ribose
Pentose-phosphate
pathways enhanced Purine
Pyrimidine
oxidative
non oxidative
Exploiting tumoral metabolic adaptation of adenocarcinoma cancer cells
for new antitumoral therapies
Phase Plane Analysis
non oxidative
oxidative
DEVELOPING DRUGS FOR NEW THERAPEUTICAL STRATEGIES
AIMING TO DISRUPT METABOLIC ROBUSTNESS OF CANCER CELLS
ROBUSTNESS
FRAGILITY
?
1-Control
MTX nM
MTX + 20 mM DHEA
MTX + 2 mM OT +
20 mM DHEA
0
0 10 20 30 40 50 60 70
MTX ( nM ) MTX ( nM )
0
0 10 20 30 40 50 60 70
MTX ( nM ) MTX (nM)
20
40
60
80
100
120
Via
bil
idad
V
iab
ilid
ad
20
40
60
80
100
120
Via
bil
idad
V
iab
ilit
y
1
2
3
4
2-MTX
3-DHEA+MTX
4-OT+DHEA+MTX
0,05 0,1 0,15
non oxidative
0
0,05
0,1
0,15
0,2
0,25
0,3
0,35
0
ox
ida
tiv
e
4 3
2
1
4 3 2
Pyrimidine
Biosynthesis
R5P PRPP
dUMP dTMP
Dihydrofolate
NADPH + H+
NADP+ Tetrahydrofolate
Serine
Glicine
Timidilate
sintase
DHFR
dTTP
DNA UMP
Purine
Biosynthesis RNA
G6P
G6PDH
TKT
N6,N10-methylene
tetrahydrofolate OT
DHEA
MTX
MTX
Oxidative/non-oxidative balance is essential to cancer cells and is a possible new target within the
cancer metabolic network for novel therapies.
DEVELOPING DRUGS FOR NEW THERAPEUTICAL STRATEGIES
AIMING TO DISRUPT METABOLIC ROBUSTNESS OF CANCER CELLS
Ramos-Montoya et al., 2006. Int J Cancer; 119(12):2733-41
Multiple hit target strategy to disrupt this balance
G6PDH and TKT activities depend on cell cycle progression and are higher in S-G2 phases. This increase
correlates with an augment in ribose phosphate synthesis in late G1-S phase. Avoiding pentose phosphate production G6PDH and TKT inhibitors are able to slow down cell cycle.
MODULATION OF PPP DURING CELL CYCLE PROGRESSION IN
HUMAN COLON ADENOCARCINOMA CELL LINE HT29
Cells do not have nucleotide reservoirs, so PPP must be regulated during cell cycle
Vizan et al., 2009. Int J Cancer; 124(12):2789-96
G6PDH activity SD
G1 rich population 457,41 14,22
S-G2 rich population 554,96 14,81
TKT activity SD
29,79 1,10
35,03 1,24
G1 rich population
S-G2 rich population
G1 rich
population
S-G2 rich population
%G1 %S %G2
0h 81,7 12,7 5,6
5h 82,8 9,8 7,4
10h 58,1 35,4 6,5
15h 35,2 59,3 5,5
20h 21,8 60,2 18,1
Increase in ribose enrichment (Smn)/hour
0
0,01
0,02
0,03
0-5h 5-10h 10-15h 15-20h
0
20
40
60
80
Ct OT+DH Ct OT+DH Ct OT+DH Ct OT+DH
0h 10h 15h 20h %
%G1 %S %G2 Cell Cycle (IC50 inhibitors)
.
Exploiting angiogenesis metabolic adaptation of HUVEC cells for new
antiangiogenic therapies
The inhibition of pentose-phosphate pathway and glycogen metabolism offers a novel
and powerful therapeutic approach, which simultaneously inhibits tumor cell
proliferation and tumor-induced angiogenesis.
Characterization of metabolic adaptation underlying growth factor
angiogenic activation: Identification of potential therapeutic targets
1.The activation of HUVEC cells produced by VEGF or
FGF produced a similar pattern of glucose usage.
2. The inhibition of the VEGF receptor caused a decrease
in the proliferation rate accompanied by a decrease in the
pentose phosphate pathway activity and glycogen
metabolism.
Vizan et al., 2009. Carcinogenesis; 30(6):946-52
3. The Direct inhibition of key enzymes of glycogen
metabolism and pentose phosphate pathways reduced
HUVEC cell viability and migration.
TNM classification of colon cancer according to American Joint Committee on Cancer (AJCC)
Primary Tumor (T)
Tis: Carcinoma in situ.
T1-4: depending on local growth degree.
Regional Lymph Nodes (N)
N0: No regional lymph node metastasis.
N1-2: depending on the number of regional
lymph nodes affected.
Distant Metastasis (M)
M0: No distant metastasis.
M1: Distant metastasis.
• TKT, and its isoenzyme TKTL1, play a key role for tumor cell metabolism.
Stage grouping according to AJCC
STAGE T N M
0 Tis N0 M0
I T1-2 N0 M0
IIA T3 N0 M0
IIB T4 N0 M0
IIIA T1-2 N1 M0
IIIB T3-4 N1 M0
IIIC T1-4 N2 M0
IV T1-4 N0-2 M1
• 46 men + 17 women (69
12 years) with colorectal cancer in different
stages were included to confirm TKTL1 as a biomarker for tumor progression.
TKTL1 AS BIOMARKER FOR TUMOR PROGRESSION IN
COLORECTAL CANCER
• TKTL1 Immunohistochemical staining of 2 mm thick sections of tumors was performed.
Stage No. Samples
I 9
II 21
III 16
IV 17
(collaboration with Dr. Antoni Castells, Hospital Clinic)
0
5
10
15
20
25
30
35
40
45
50
N 0 N 1-2
** P = 0.0014
TK
TL
1 e
xp
ressio
n
(Rela
tive v
alu
e x
1000)
TKTL1 increase correlates significantly
(p=0,0014) with regional lymph node affection degree (N).
0
5
10
15
20
25
30
35
40
M0 M1
*** P = 0.0004
TK
TL
1 e
xp
ressio
n
(Rela
tive v
alu
e x
1000)
TKTL1 levels decrease
significantly (p=0,0004) when distant metastasis appears (M).
RESULTS
0
5
10
15
20
25
30
35
40
T 1-2 T 3-4
* P = 0.029
TK
TL
1 e
xp
ressio
n
(Rela
tive v
alu
e x
1000)
There is a slightly correlation
between TKTL1 levels and local growth (p=0,029).
Stage III tumors present the highest levels
of TKTL1 expression (p=0,000008).
Stage Mean SD
I 13,3 7,9
II 20,8 9,9
III 32,9 11,5
IV 13,7 8,7
Stage I Stage II Stage III Stage IV
0
10
20
30
40
50*** P = 0.000008
TK
TL
1 e
xp
ressio
n
(Re
lative
va
lue
x 1
00
0)
Stage I Stage II Stage III Stage IV
0
10
20
30
40
50*** P = 0.000008
Stage I Stage II Stage III Stage IV
0
10
20
30
40
50
Stage I Stage II Stage III Stage IV
0
10
20
30
40
50*** P = 0.000008
TK
TL
1 e
xp
ressio
n
(Re
lative
va
lue
x 1
00
0)
Diaz-Moralli et al. Plos One 2011; 11;6(9) e25323.
METABOLIC CHANGES ACCOMPANYING TUMOR CELL
DIFFERENTATION
N
NHOH
O O
TSA
Butyrate (NaB)
ONa
O
Histone deacetylase enzymes downregulate genes that cause or induce cell differentiation.
Deacetylated chromatin
no gene expression
Acetylated chromatin
HDAC HAT HDI
Gene expresion
HDI
HT29 Differentiation
HT29 TSA
Butyrate (NaB)
Butirato o TSA
HDAC
Butyrate or TSA
HDAC
HT29
NADPH
F6P
GAP
PYR LACTATE
OAA Ac-CoA
GLUTAMATE
RIBOSE
GLUCOSE
G6P G6PDH
PDH
- cetoglutarate - - -
Transformation
Differentiation
NADPH
F6P
GAP
PYR LACTATE
OAA Ac-CoA
GLUTAMATE
RIBOSE
GLUCOSE
G6P
- cetoglutarate - - -
HT29
METABOLIC CHANGES ACCOMPANYING TUMOR CELL
DIFFERENTATION
Butyrate and TSA show similar effects on HT29 cells. Other fatty acids that are not able to induce differentiation
not induce this changes -> The metabolics effects induce are due to histone deacetylase inhibition.
Alcarraz-Vizan et al 2010 Metabolomics
Jurkat cells + low dosis edelfosine
(apoptosis < 5%)
NADPH
F6P
GAP
PYR LACTATE
OAA Ac-CoA
RIBOSE
GLUCOSE
G6P G6PDH
PDH
- cetoglutarate - - -
EARLY METABOLIC CHANGES PRECEED EDELFOSINE (ET-18-OCH3 )
INDUCED APOPTOSIS
Jurkat cells without edelfosine
NADPH
F6P
GAP
PYR LACTATE
OAA Ac-CoA
RIBOSE
GLUCOSE
G6P G6PDH
PDH
- cetoglutarate - - -
•Low edelfosine (before apoptosis) : Krebs cycle and RNA synthesis increase , PPP decrease
•Higher dosis (apoptosis): enhanced metabolic effects and ROS production
Selivanov et al. BMC Systems Biology 2010, 4:135
EXTENDING METABOLIC MODELS TO ROS
PRODUCTION:
Important component of redox status is the level of reactive
oxygen species (ROS) produced in mitochondria.
Algorithms developed for isotopomer analysis and study of cancer
metabolism network adaptation can be used to cope with the
complexity of modelling ROS production and energetic metabolism in
muscle. Selivanov et al. 2009 PLOS Computational Biology, In Press
.
0: Q-Q-bh-b
l-c
1-FeS-Q-Q
xxxxx011 ⇆xxxxx101+ 2H+
p
vf30
= kf30
·Cxxxxx011
vr30
=k r30
·Cxxxxx101
·Hp
2
Fe3++ QH2 ⇆
Fe2++ Q-+ 2H+
p
0: Q-Q-bh-b
l-c
1-FeS-Q-Q
xxxxx011 ⇆xxxxx101+ 2H+
p
vf30
= kf30
·Cxxxxx011
vr30
=k r30
·Cxxxxx101
·Hp
2
0: Q-Q-bh-b
l-c
1-FeS-Q-Q
xxxxx011 ⇆xxxxx101+ 2H+
p
vf30
= kf30
·Cxxxxx011
vr30
=k r30
·Cxxxxx101
·Hp
2
0: Q-Q-bh-b
l-c
1-FeS-Q-Q
xxxxx011 ⇆xxxxx101+ 2H+
p
vf30
= kf30
·Cxxxxx011
vr30
=k r30
·Cxxxxx101
·Hp
2
Fe3++ QH2 ⇆
Fe2++ Q-+ 2H+
p
1: Q-Q-bh-b
l-c
1-FeS-Q-Q
Fe2++ c1
ox ⇆Fe3++ c1
red
xxxx01xx⇆xxxx10xx
vf31
= kf31
·Cxx01
vr31
=kr31
·Cxx10
1: Q-Q-bh-b
l-c
1-FeS-Q-Q
Fe2++ c1
ox ⇆Fe3++ c1
red
xxxx01xx⇆xxxx10xx
vf31
= kf31
·Cxx01
vr31
=kr31
·Cxx10
1: Q-Q-bh-b
l-c
1-FeS-Q-Q
Fe2++ c1
ox ⇆Fe3++ c1
red
xxxx01xx⇆xxxx10xx
vf31
= kf31
·Cxx01
vr31
=kr31
·Cxx10
2: Q-Q-bh-b
l-c
1-FeS-Q-Q
Q-+ blox⇆b
lred+ Q
xxx0xx01 ⇆xxx1xx00
vf32
= kf32
·Cx0xx01
vr32
=kr32
·Cx1xx00
2: Q-Q-bh-b
l-c
1-FeS-Q-Q
Q-+ blox⇆b
lred+ Q
xxx0xx01 ⇆xxx1xx00
vf32
= kf32
·Cx0xx01
vr32
=kr32
·Cx1xx00
2: Q-Q-bh-b
l-c
1-FeS-Q-Q
Q-+ blox⇆b
lred+ Q
xxx0xx01 ⇆xxx1xx00
vf32
= kf32
·Cx0xx01
vr32
=kr32
·Cx1xx00
The scheme of reactions performed by complex III as it is generally accepted. One of two electrons taken from ubiquinol (QH2),
which releases its two protons into the intermembrane space, recycles through cytochromes bh and bl reducing another quinone.
The other electron continues its way to oxygen through cytochromes c1 and c and complex IV. Complexes I and II provide QH2.
•The detailed modeling of electron transport in mitochondria identified two steady state
modes of operation (bistability) of respiratory complex III at the same
microenvironmental conditions.
•Normally complex III is in a low ROS producing mode, temporal anoxia could switch it to
a high ROS producing state, which persists after the return to normal oxygen supply.
•This prediction, which we qualitatively validated experimentally, explains the
mechanism of anoxia-induced cell damage.
Recognition of complex III bistability may enable novel therapeutic
strategies for oxidative stress
Selivanov et al., 2009. PLOS Comput. Biol. and Selivanov et al 2011, PLOS Comput. Biol.
CONCLUSIONS FROM ROS MODELLING
Clinical Data connection
signalling
cell damage
G l y c o l y s i s
L a c
T C A c y c l e
antioxidant system
G l c
P y r
L a c N A D
N A D H
N A D
M i t o c h o n d r i a
A c C o A
O A A
C i t
S u c c
N A D
N A D H
A D P
A T P
O 2 A D P
A T P
O 2 uptake
Exhalates
ROS
Omics
in
Blood
O 2 transport
Clinical Data connection ”OMICS” in biopsies
RESPIRATION
Developing a modelling environment, which links clinical characteristics
with the redox status of cell
Integration of existing models
• Skeletal muscle bioenergetics
– sub-cell
• Mitochondrial reactive oxygen species (ROS) generation
– sub-cell
• Central and peripheral O2 transport and utilization
– organ system (heart, lung, hemoglobin, skeletal muscle)
• Pulmonary gas exchange
– organ (lungs)
• Spatial heterogeneities of lung ventilation and
perfusion
– tissue
SYNERGY: Modeling and simulation environment for systems medicine: chronic
obstructive pulmonary disease -COPD- as a use case (FP7)
Dr. Silvia Marín
Dr. Gema Alcarraz-Vizán
Dr. Vitaly Selivanov
Susana Sánchez
Dr. Pedro de Atauri
ACKNOWLEDGEMENTS
Group of Integrative Biochemistry
Department of Biochemistry and Molecular Biology, University of Barcelona
Dr. Josep Centelles
Hospital Clínic-IDIBAPS, University
of Barcelona: Pneumology service,
Institut del Torax,, directed by Dr.
Josep Roca and Gastroenterology
Department Dr Antoni Castells
Financial support: SAF2005-01627, SAF2008-00164 from the Ministerio de Ciencia y Tecnologia of the
Spanish Government
SYNERGY, METAFLUX, ETHERPATHS from the European Union (FP7)
ICREA ACADEMIA Award Autonomous Government of Catalonia
Collaborators
Santiago Díaz-Moralli
Igor Marín
Miriam Zanuy
Roldán Cortés
Adrián Benito