Midollare del surrene e disfunzione

autonomica

Giuseppe Rengo, MD, PhD

Department of Translational Medical Sciences

University of Naples “Federico II”

Salvatore Maugeri Foundation

Scientific Institute of Telese Terme – IRCCS –

Sympathetic Nervous System

Lymperopoulos A, Rengo G, Koch WJ. Circ Res 2013;113:739-753.

Haider N et al. J A C C C a r d i o v a s c u l a r I m a g i n g 2010

Adrenergic Excess, hNET1 Down-Regulation,

and Compromised mIBG Uptake in Heart Failure

Rengo G et al. J Gerontol A Biol Sci Med Sci submitted 2015

Impact of aging on cardiac sympathetic innervation measured

by 123I-mIBG imaging in patients with heart failure

CARDIOMYOCYTE

extracellular

intracellularACβ-AR

β γ

PKA

ATP cAMP

CA CACA

CA

CA CA

CA

CA

CACA

P

GRK2

contractility

Endocytosis and

degradation

Physiologic conditions

Gsα

Heart Failure

CA

CA

CA

CA

CA

CA CA

CACA

CA

CA

CA

CA

CA

Positive

inotropy(βARKct

β-blocker

Exercise Training)

SNS Hyperactivity

Myocardial oxigen consumption (J Mol Cell Cardiol 1985);

Cardiac interstitial fibrosis (Eur J Pharmacol 2004);

Myocyte apoptosis (Cardiovasc Res 2004);

Adverse remodeling (Am J Physiol Heart Circ Physiol 2007);

Reduction of the inotropic reserve (NEJM 1982);

Myocardial ROS production (J Cell Mol Med 2007);

Risk of arrythmias (NEJM 1991);

Renin-angiotensin-aldosterone system (Am J Physiol 1992);

Renal and peripheral vascular resistance (JACC 2009);

+

-

β-blockers

Lymperopoulos A, Rengo G, Koch WJ. Circ Res 2013.

The α2A-AR is the main presynaptic inhibitory autoreceptor in the CNS, lowering sympathetic

outflow/BP in response to α2-AR agonist drugs and, along with the α2C-AR, inhibits NE release

in mouse atria (Hein et al., 1999, Nature 402:181–184). α2-ARs are responsible for the

autocrine feedback inhibition of CA release from the adrenal gland (Brede et al., 2003, Mol.

Endocrinol. 17:1640-1646).

α2ARs of cardiac sympathetic nerves and adrenal gland play an essential role in regulation of

SNS activity/outflow in HF (Brede et al., 2002, Circulation 106, 2491-2496, Brum et al., 2002,

Am. J. Physiol. Heart Circ. Physiol. 283, H1838-H1845, Small et al., 2002, N. Engl. J. Med.

347, 1135-1142).

Lymperopoulos A, Rengo G et al Nat. Med. 2007

Adrenal GRK2 upregulation mediates sympathetic overdrive

in heart failure

#

sham

HF

UK14304+Nicotine

*

0

10

20

30

40

50

60

70

Nicotine

Ep

ine

ph

rin

e s

ec

reti

on

(% o

ve

r b

asa

l)

0

10

20

30

40

50

60

70

Nicotine UK14304+NicotineN

ore

pin

ep

hri

ne s

ec

reti

on

(% o

ve

r b

asa

l)

#

**

*, p<0.01 vs. Nicotine-sham, **, p<0.05, vs. Nicotine-sham, #, p<0.05 vs. Nicotine-HF, n=6

Desensitization of α2ARs in HF

rat adrenal-derived chromaffin cells

Lymperopoulos A, Rengo G et al Nat. Med. 2007

-10

0

10

20

30

40

50

60

70

Nicotine UK14304+NicotineNo

rep

inep

hri

ne s

ecre

tio

n

(% o

ver

basal)

HF rat chromaffin cells

-10

0

10

20

30

40

50

Nicotine UK14304+Nicotine

Ep

ine

ph

rin

e s

ec

reti

on

(% o

ve

r b

asa

l)

*

#

*

#

GFP

bARKct

*, p<0.05 vs.

UK14304+Nicotine-

GFP, p<0.01 vs.

Nicotine-bARKct, #,

p<0.05 vs. Nicotine-

GFP, n=9

βARKct restores adrenal α2AR-induced CA secretion

inhibition in HF rats

Lymperopoulos A, Rengo G et al Nat. Med. 2007

Lymperopoulos , Rengo et al. Mol Ther 2008

Adrenal GRK2 upregulation mediates sympathetic

overdrive in heart failure

0

200

400

600

800

1000

1200

AdGFP AdbARKct

Norepinephrine

Epinephrine

Pla

sm

a leve

ls

(pg/m

l)

**

*, p<0.05 vs. AdGFP Lymperopoulos A, Rengo G et al Nat. Med. 2007

*, p<0.05, compared to AdGFP, ^,

p<0.05, compared to AdGFP, **,

p<0.05, compared to AdGRK2

*

*

^,*

*

^,*

*Pla

sm

a l

evels

(pg/m

l)

0

50

100

150

200

250

300

350

400

AdGFP AdGRK2 AdbARKct

Epinephrine

Norepinephrine

Manipulation of adrenal GRK2 levels

modulates plasma CA level in vivo

GRK2

bARKct

actin

AdGFP AdGRK2 AdbARKct

Immunoblotting

in rat adrenals

Lymperopoulos , Rengo et al. Mol Ther 2008

10X

Injection

Negative Control

Gallein Reduced Plasma CAs and adrenal Hypertrophy,

and restores α2-AR feedback inhibition of CA release

Kamal FA et al. JACC 2014.

Cortex

Medulla

Cortex

Medulla

Cortex

Medulla

Ab-TH Ab-GRK2 Blank

20

30

40

50

0

10

-10

60

70

Ep

i s

ec

reti

on

(%

ove

r b

as

al)

*

* #

20

30

40

50

0

10

-10

60

70

-20

-30

NE

pi

se

cre

tio

n (%

ove

r b

as

al)

*

* #

Nicotine

UK + Nicotine

GRK2 regulates adrenal α2-AR-CA production axis

in human chromaffin cells

Rengo G et al. Unpublished data

* *

*, p<0.05, vs. Nicotine; #, p<0.05, vs. UK+Nicotine of other groups

Kamal FA et al. JACC 2014

Gallein reduces CA secretion and normalizes α2-AR feedback

inhibition in pheochromocytoma human adrenal medulla

0

2000

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12000

14000

16000

1 2

+dp/dT basal

+dp/dT max

Young OldYoung

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1 2

YoungOldYoung

EF

(%

)

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-9000

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-7000

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-5000

-4000

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-2000

-1000

0

-dp/dT basal

-dp/dT max

Rengo G et al. Unpublished data

*, p<0.05, vs. Young

*

*

Effects of age on cardiac function and inotropic reserve

Age-related alterations of adrenal GRK2-α2-adrenergic receptor-

catecholamine production axis

GRK2

GAPDH

Rengo G et al. Unpublished data

0,00

50,00

100,00

150,00

200,00

250,00

300,00

350,00

400,00

1 2

Epi

NE

YoungOldYoung

Pla

sma

level

s (p

g/m

l)

0,0000

0,5000

1,0000

1,5000

2,0000

2,5000

1 2

GR

K2/G

AP

DH

pro

tein

lev

els

(AU

)

Young OldYoung

0,0000

10,0000

20,0000

30,0000

40,0000

50,0000

60,0000

1 2Young OldYoung

*

*

*

*

*, p<0.05, vs. Young Addre

nal

alf

a2-A

R d

ensi

ty

(fm

ol/

mg o

f m

embra

ne

pro

tein

)

Rengo G et al. Unpublished data

α2-adrenergic receptor responsiveness in adrenal chromaffin cells

extracted from young and old rats

*, p<0.05, vs. Nicotine

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0,45

0,5

1 2

Nic

UK+Nic

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0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0,45

0,5

1 2

Nic

UK+Nic

Ep

inep

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secr

etio

n

(% o

ver

bas

al)

No

repin

eph

rin

e se

cret

ion

(% o

ver

bas

al)

YoungYoung Old Young Old

**

Rengo G et al. Unpublished data

Effects of GRK2 inhibition on α2-adrenergic receptor

responsiveness in adrenal chromaffin cells extracted from old rats

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0,45

1 2

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UK+Nic

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UK+Nic

Epin

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repin

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cret

ion

(% o

ver

bas

al)

YoungOld-GFP Old-

GRK2ctYoung

Old-GFP Old-

GRK2ct

**

*, p<0.05, vs. Nicotine

CONCLUSIONS

• SNS hyperactivity is a salient characteristic of chronic

HF and of physiological ageing

• Cardiac β-AR dysregulation is strictly related to SNS

overdrive

• Adrenal medulla seems to play a relevant role in the

determination of CA circulating levels

• GRK2-mediated α2-adrenergic receptor dysfunction

is a crucial mechanism of SNS overdrive in HF

• GRK2 regulates CA realease also from human

chromaffin cells

• GRK2 inhibition in chromaffin cells extracted from old

rats resulted in enhanced α2-AR responsiveness and

reduced CA release

Acknowledgements

Dpt. of Translational Medical Sciencies

Federico II University of Naples:

Prof. Nicola Ferrara, MD

Prof. Dario Leosco, MD, PhD

Alessandro Cannavo, MS, PhD

Pina Gambino, MS, PhD student

Klara Komici, MD

Maria Loreta D’Amico, MS, PhD student

Andrea Elia, MS

Roberto Formisano, MD

Laura Petraglia, MD

Grazia Daniela Femminella, MD, PhD

Claudio de Lucia, MD

Daniela Liccardo, MS, PhD

Gennaro Pagano, MD

Center for Translational Medicine, Temple

University, Philadelphia, PA:

Walter J Koch, PhD

Erhe Gao, MD, Joseph E Rabinowitz, PhD

Dept. of Pharmaceutical Sciences, Nova

Southeastern University, Fort Lauderdale,

FL:

Anastasios Lymperopoulos, PhD