estudi de la funció del coactivador transcripcional pgc-1β en el teixit adipós blanc i la seva...
DESCRIPTION
Presentació predoctoral de Natàlia Enguix a la 6a Jornada Científica del VHIR. Consulta el vídeo després de la darrera diapositivaTRANSCRIPT
Study of the role of the PGC-1β transcriptional coactivator
in white adipose tissue and its implication in the development of insulin resistance
Natàlia Enguix Elena
Laboratory of Metabolism and Obesity
Unit of Diabetes and Metabolism
Fatty acids
Fatty acids
Acyl-CoAs
Diacylglycerols
Ceramides
Insulin
IRS
PKC ATP
STOP
Thiazolidinediones
Adipogenesis
Mitochondrial Biogenesis Oxidative Metabolism
Fatty acid uptake Triglycerides accumulation
Lipid oxidation
White AdiposeTissue
Fatty Acid Oxidation
mtDNA replication/transcription
Oxphos System
NRF1/2
ERR
PGC-1
PGC-1
PGC-1
PGC-1
COLD EXPOSURE
EXERCISE
PPAR
Nucleus
TFAM
(Patti et al, PNAS 2003)
Skeletal Muscle
Decreased mitochondrial mass and function in diabetic patients is associated with low PGC-1 expression
White Adipose Tissue
(Bogacka et al, Diabetes 2005)
Mitochondrial Mass PGC-1 mRNA
No Diabetic Control
Placebo Pioglitazone
Diabetic
No Diabetic Control
Placebo Pioglitazone
Diabetic
Control
Diabetic Control
Diabetic
Expression of mitochondrial genes and mitochondrial biogenesis is not altered in WAT of PGC-1-FAT-KO mice
loxP loxP
1 2 3 4 5 6 7 8 9 10 11 12 13
1 2 3 6 7 8 9 10 11 12 13
+ aP2-Cre
Floxed allele
PGC-1-FAT-KO
0,0
0,5
1,0
1,5
a.u
.
mtDNA
wt ko 0
0,5
1
1,5
mR
NA
(a.
u.)
Gene Expression White Adipose Tissue
mR
NA
(a.
u.)
1.2
0.8
0.4
0
1.6
Kidney Liver Testis Spleen Muscle Thymus BAT WAT
Gene Expression Wildtype
PGC-1-FAT-KO
** **
Pardo et al. PLoS One (2011)
Rosiglitazone-induced mitochondrial biogenesis and function is independent of PGC-1
Rela
tive m
tDN
A c
onte
nt
mtDNA
Cont. Rosig
2.5
2.0
1.5
1.0
0.5
0
Citrate synthase
CS
activity
m
ol/m
g.m
in
Cont. Rosig
2.5
2.0
1.5
1.0
0.5
0
3.0
3.5
0
0.5
1.0
1.5
2.0
2.5
3.0
mR
NA
expre
ssio
n
(Rela
tive u
nits)
PGC-1
Wt FAT-KO COXII COXIV CYCS ATP5b CS ACO2 MCAD
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
mR
NA
expre
ssio
n
(Re
lative
units)
Wt Cont. FAT-KO Cont. Wt Rosig. FAT-KO Rosig.
Pardo et al. PLoS One (2011)
0
0,2
0,4
0,6
0,8
1
Pre Conf Post d0 d2 d4 d6 d8
mR
NA
(R
elat
ive
un
its)
Days during differentation
PGC-1β
PPARγ
Pref-1
0
0,2
0,4
0,6
0,8
1
1,2
1,4
mR
NA
(R
ela
tive
un
its)
PGC-1β ATGL
PGC-1β is highly expressed in mature white adipocytes
Pref-1
* **
*
0
0,5
1
1,5
2
2,5
NRF-2 NRF-1 ERRα ERRγ RIP140 PGC-1β
mR
NA
(R
ela
tive
un
its)
Wild type + Vehicle
Wild type + Rosiglitazone
Gene Expression
Generation of PGC-1β-FAT-KO mice
2 3 5 8 1 4 6 7 9 10 11 12
2 3 8 1 6 7 9 10 11 12
+ aP2Cre
Floxed allele
PGC-1β-FAT-KO
0
0,2
0,4
0,6
0,8
1
1,2
1,4
1,6
BAT iWAT Adipocytes Kidney Lungs Soleus Spleen Testis Thymus
mR
NA
(a.
u.)
PGC-1β Expression
Wildtype
PGC-1B-FAT-KO
Adipose tissues
** ** **
30ºC
Gene expression profiling in WAT of PGC-1β-FAT-KO mice
Microarray DNA
Wildtype (n=5)
Knockout (n=5)
PGC-1β regulates expression of genes involved in oxidative metabolism in white adipose tissue
0
0,2
0,4
0,6
0,8
1
1,2
1,4
NDUFAB1 NDUFB9 SDHB CytC1 CytCs Cox5a Cox5b Cox7a1 ATP5a1 ATP5o
mR
NA
(R
ela
tive
un
its)
Wild type
PGC-1β-FAT-KO
0
0,2
0,4
0,6
0,8
1
1,2
1,4
Aco2 Idh3a Idh3b MDH2 LDHB PGK1 Elovl6 Cpt1b Cidea Cideb
mR
NA
(R
ela
tive
un
its)
Wild type
PGC-1β-FAT-KO
* * *
** * *
* *
C I C II Cyt C C IV C V
OXPHOS
TCA Cycle Glycolysis Lipid Metabolism / Oxidation
* * *
** *
* **
*
*
Gene Expression White Adipose Tissue
Wild type PGC-1β-FAT-KO
Aconitase
ATPSynβ
NDUFB9
COX IV
SDHB
Cyt c
α-tubulin
PGC-1β-FAT-KO mice exhibit reduced levels of TCA cycle and OxPhos proteins and impaired oxidative capacity in white adipose tissue
White Adipose Tissue
0
0,05
0,1
0,15
0,2
μm
ole
/mg
/min
Citrate Synthase Activity
0
0,01
0,02
0,03
μm
ole
/mg
/min
Cytochrome Oxidase Activity
WT KO WT KO
* *
Rosiglitazone-induced mitochondrial gene expression and function is mediated by PGC-1β
0
1
2
3
4
CoxIV Cox8b Cox7a1 CytCs ATPSynB Aco2 CS Cpt1b
mR
NA
(a.
u.)
Gene Expression White Adipose Tissue
Wt + vehicle
KO + vehicle
Wt + Rosiglitazone
KO + Rosiglitazone**
** *
*
**
* * *
*
0
100
200
300
400
Vehicle Rosiglitazone
nm
ol/
mg·
min
Citrate Synthase Activity
*
0
1
2
3
4
5
Vehicle Rosiglitazone
a.u
.
mtDNA Content
Lack of PGC-1β in adipocytes does not induce whole body or tissue-specific insulin resistance
50
150
250
350
450
0 20 40 60 80 100 120
Glu
cose
(m
g/d
L)
Time (min)
Glucose Tolerance Test
Wt + Vehicle
KO + Vehicle
Wt + Rosiglitazone
KO + Rosiglitazone
0
50
100
150
0 20 40 60 80 100 120
Glu
cose
(m
g/d
L)
Time (min)
Insulin Tolerance Test
Conclusions
PGC-1β in white adipose tissue specifically regulates the expression of genes involved in mitochondrial energy production.
PGC-1β but not PGC-1α mediates the rosiglitazone-induced expression of mitochondrial genes and the oxidative capacity of white adipose tissue.
Full mitochondrial oxidative function is not required for the insulin-sensitizing effects of thiazolidinediones.
Thank You
Metabolism and Obesity Laboratory
PGC-1β regulates mitochondrial gene expression in 3T3-L1 adipocytes
0
1
2
3
4
mR
NA
(a.
u.)
PGC-1α
0
1
2
3
4
mR
NA
(a.
u.)
PGC-1β
0
2
4
6
mR
NA
(a.
u.)
CytCs
0
1
2
3
mR
NA
(a.
u.)
IDH3β
**
0
1
2
3
mR
NA
(a.
u.)
ATPSynβ
0
1
2
3
mR
NA
(a.
u.)
NDUFB9
siControl: siPGC-1α: siPGC-1β:
+ - - - + - - - - + - + - + - + - - + + - - + +
+ - - - + - - - - + - + - + - + - - + + - - + +
DMSO Rosiglitazone DMSO Rosiglitazone
siControl: siPGC-1α: siPGC-1β:
+ - - - + - - - - + - + - + - + - - + + - - + +
+ - - - + - - - - + - + - + - + - - + + - - + +
DMSO Rosiglitazone DMSO Rosiglitazone
0
1
2
3
4
5
6
7
Re
lati
ve U
nit
s
Oxygen Consumption Rate 3T3L1 Adipocytes
P=0.09
P=0.11
P=0.16
siControl: siPGC-1α: siPGC-1β:
+ - - - + - - - - + - + - + - + - - + + - - + +
+ - - - + - - - - + - + - + - + - - + + - - + +
Basal CCCP
DMSO
Rosiglitazone
Gene expression
** ** ** **
** ** **
**
** **
* **
** **
** ** ** **
* **
** **
** **