Transcript ANNA MOLES Institute of Neuroscience CNR

A metabolic role for the VGFderived peptides
ANNA MOLES
Institute of Neuroscience CNR- Rome, Italy
Neurotrophins are proteins required for neuronal differentiation
and survival. Pioneering work by Rita Levi-Montalcini, Stanley
Cohen and Viktor Hamburger in the 1950s and early 1960s
identified nerve growth factor (NGF) and demonstrated that this
protein was required for sympathetic neuron survival both in
vivo and in vitro. The later purification and characterization of
brain-derived neurotrophic factor (BDNF), a close relative of
NGF, allowed the cloning of additional family members. Six
members of the neurotrophin family have been identified in
vertebrates, namely NGF, BDNF, NT-3, NT-4/5, NT-6 and NT-7.
These polypeptides bind, with different affinities, to the Trk
family of receptor tyrosine kinases (TrkA, TrkB and TrkC) and
with similar affinities to the p75 neurotrophin receptor
(p75NTR), a member of the tumor necrosis factor receptor
Vgf gene discovered in PC12 cells
following NGF treatment
(Levi et al., Science 1985)
Possenti et al PNAS, 1992
TISSUE SPECIFIC EXPRESSION
OF VGF
Salton et al. Front Neuroendocrinol, 2000
VGF a possible link between neurotrophines and energy homeostasis?
Nature Neuroscience 6, 736 - 742 (2003)
Brain-derived neurotrophic factor regulates energy balance downstream of
melanocortin-4 receptor
Baoji Xu1, 5, Evan H Goulding2, Keling Zang1, David Cepoi3, Roger D
Cone3, Kevin R Jones4, Laurence H Tecott2 & Louis F Reichardt1
Resistant to several types of obesity
VGF-gene acts downstream of MC4R in PVN, LH or brain
stem nuclei, that project via the autonomic nervous system
to peripheral metabolic tissues and regulate energy
homeostasis
Vgf encodes a 617 amino acid protein in
rodents that, upon processing by the
neuroendocrine-specific
prohormone
convertases (PC)1/3 and PC2, yields several
peptides that are stored in dense core granules
and secreted through the regulated pathway
Ferri & Possenti, Trends Endocrinol Metab, 1996
VGF
CONSTRUCTS
Trombin cleaves at :
…...LVPR GSPRTLQ…..
TROMBIN
GST
VGF
pep20
pep20-10
pep10
pep10-3
pep3
NAPPEPVPPPRAAPAPTHVRSPQPPPPAPARDELPDWNEVLPPWDREEDEVFPPGPYHPFPNYIRPR
TLQPPASSRRRHFHHALPPARHHPDLEAQARRAQEEADAEERRLQEQEELENYIEHVLLHRP
IDENTIFICATION OF VGF
DERIVED PEPTIDE
TLQPPASSRRRHFHHALPPARHHPDLEAQARRAQE
EADAEERRLQEQEELENYIEHVLLHRP
Mouse TLQP-21 sequence
Human TLQP-21 sequence
Can TLQP-21 modulate energy homeostasis?
Experimental procedure:
Male CD1 mice injected icv with TLQP-21 (6nmol/day) for 14
days with Alzet microsmotic pumps.
basal
Chronic TLQP-21 icv treatment
Body weight
Food intake
0
1
3
5
days
Surgery, start
treatment
7
9
11
13
HYPOTHALAMUS
BAT
AGRP
POMC
b1AR
NPY
CRH
b2AR
MCH
b3AR
GHS-R
UCP1
Body weight
UCP2
Food intake
UCP3
Locomotor activity
Norepi
Temperature
Energy expenditure
Triglycerides
FFA/TG
Leptine
Ghreline
BAT
THYROID
fT3
fT4
WAT
ADRENALS
UCP1
UCP3
UCP2
PPAR-d
Epinephrine
b1AR
PGC-1a
Norepinephrine
b2AR
Adipon
Corticosterone
b3AR
HemeOx1
Norepi
WAT
Increased T,
epinephrine and
resting EE & adrenal
weight
Normal food intake
and locomotor
activity,and thyroid
hormones
Decreased TG and increased FFA/TG ratio;
reduction in WAT and leptin
slight
No changes in the hypothalamus; b2-AR increase in BAT;
UCP1, PPAR-delta and b3-AR in WAT
BAT
WAT
WAT
WAT
CONCLUSION 1
Central TLQP-21 determines:
Increased EE, hyperthermia, conversion of TG in FFA
Proposed mechanism:
Increased sympathetic stimulation to WAT and adrenomedullary
release of E 
Increased UCP1 and catabolic mediator in the WAT 
Can central TLQP-21 affects development of diet induced obesity?
Experimental procedure:
Male CD1 mice injected icv with TLQP-21 (6nmol/day) for 14
days with Alzet microsmotic pumps.
Starting the day of surgery mice received a HF diet (+20% lard).
basal
Chronic TLQP-21 icv treatment
Body weight
Food intake
0
1
3
5
days
Surgery, start
treatment
7
9
11
13
Body weight
Leptin
Ghrelin
Food intake
White adipose tissue
Can TLQP-21 modulate
energy homeostasis and
somatic growth by
modulating the GH/IGF-1
axis?
NO
EFFECTS OF TLQP-21
-Increases energy expenditure
-Increase epinephrine and inhibit norepinephrine in the long term
-Activate catabolic markers in the adipose tissue
-Prevents diet-induced in obesity prone individuals
-Increase heart rate
-…..
Modulation of the ANS and the sympathoadrenomodellurary
pathways.
GENERAL CONCLUSION 1
TLQP-21 is the first VGF-derived peptide which is
involved in energy metabolism
VGF -/-
TLQP-21
Other VGF-derived peptides should
have an anabolic role
GENERAL CONCLUSION 2
TLQP-21 centrally increases energy expenditure
GENERAL CONCLUSION 3
TLQP-21 blocks development of diet induced
obesity by increasing energy expenditure
PSYCHOSOCIAL STRESS PROCEDURE
BASELINE
(3 days)
SOCIAL INTERACTION
(twice a day x 5 days)
COHABITATION
(16 days)
P
S
Y
C
H
O
S
O
C
I
A
L
S
T
R
E
S
S
FOOD INTAKE IN DOM, SUB AND CONTROL
MICE DURING PS (COHABITATION)
food ingested from day 5-day 21 (gr)
110
**
**
100
90
80
70
60
50
40
30
20
10
0
ANOVA F 2,25 = 4.75 p< 0.05
** p< 0.01 vs CONTROL
MEAN DAILY METABOLIC RATE (kcal/h),AND LOCOMOTION
IN DOM SUB AND CONTROL MICE BEFORE AND AFTER
THE PS PROCEDURE
Mean activity
Mean daily Metabolic rate
600
**
0,85
0,8
500
0,75
counts
400
0,7
0,65
300
200
0,6
100
0,55
0,5
0
dom
sub
con
dom
sub
con
Basale
Basale
Basale
Post
Post
Post
ANOVA F2,13 = 6,77 p< 0.01
**p< 0.01 vs CONTROL
Dom
Basal
Sub
Basal
Con
Basal
Dom
Stress D22
Sub
Stress D22
ANOVA F2,13 = 0.00 NS
Con
Stress D22
Institute of Neuroscience CNR Rome
FRANCESCA D’AMATO
ALESSANDRO BARTOLOMUCCI
FLAMINIA PAVONE
LUCIANA GARBUGINO
ROBERTO COCCURELLO
Institute of Neurobiology and
Molecular Medicine CNR Rome and
Department of Neurobiology Univ. of
Rome Tor Vergata
ANDREA LEVI
ROBERTA POSSENTI
ROBERTO RIZZI
CINZIA SEVERINI
GIORGIO LA CORTE
Univ. of Rome La Sapienza
DONATELLA BARRA
EUGENIA SCHININA’
PINA MIGNOGNA
ALESSANDRA GIORGI
Univ. of Cagliari
GIAN LUCA FERRI
CARLA BRANCIA
S.Lucia Foundation, Rome
T. PASCUCCI
Sigma Tau,SPA, Pomezia
R. CONTI
A.CAPRIOLI
F.BORSINI
O.GHIRARDI
Univ. Milan-Bicocca
TORSELLO, V. LOCATELLI
Univ. Of Milan
A.E. RIGAMONTI, E.E. MULLER