Adrenomedullin and cardiovascular

responses in sepsis

TU JieMarch 19, 2004

Introduction

• Sepsis, septic shock: the major cause of

high mortality in intensive care units

• Adrenomedullin (ADM or AM): produced in

abnormally large quantities

• Molecular structure of AM: 52-amino

acid peptide, first reported in 1993

• Distribution of AM: plasma, heart,

lung, kidney, stomach, endothelial

cells, smooth muscles, epithelial cells

…

• Molecular structure of AM: 52-amino acid pep

tide, first reported in 1993

• Distribution of AM: plasma, heart, lung, kidn

ey, stomach, endothelial cells, smooth muscl

es, epithelial cells …

• Functions of AM: endocrine factor as well as

a local autocrine and paracrine factor with ca

rdiovascular and renal actions

be of particular interest in pathophysiology of

sepsis

AM receptor and AM-binding protein

• the existence of AM binding sites in blood

vessels, heart, lung, spleen, liver …

• two AM receptor subtypes: CGRP-like receptor

and AM specific receptor

• RAMPs: a novel family of single transmembrane pr

oteins, three isoforms

• CRLR: calcitonin-receptor-like receptor, an orphan

recptor with seven transmembrane domains

• the function of

RAMP/CRLR complex (depending on the

expression of RAMP)

RAMP1/CRLR=CGRP recptorRAMP1/CRLR=CGRP recptor

RAMP2/CRLR=AM receptorRAMP2/CRLR=AM receptor

RAMP3/CRLR ? AM receptorRAMP3/CRLR ? AM receptor

• AM binding protein: 120 and/or 140 kDa in ma

mmalian blood

• AMBP-1: identical to human complement fact

or H

• AMBP-1 may affect the function and bioactivit

y of AM

• The circulating level of AMBP-1 during sepsis:

remains unknown

Upregulation of AM in sepsis

Plasma concentration of adrenomedullin in patients with septic shock and in control patients. **p <0.01 between groups.

Plasma concentration of adrenomedullin in patients with septic shock and in control patients. **p <0.01 between groups.

Changes in cardiac ADM levels at 5 and 20 h after cecal ligation and puncture (CLP) or sham-operation (sham). *P<0.05 versus the respective sham.

Changes in cardiac ADM levels at 5 and 20 h after cecal ligation and puncture (CLP) or sham-operation (sham). *P<0.05 versus the respective sham.

Nishio K, Akai Y, Murao Y et al. Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock: Crit Care Med. 1997, 25(6):953-7

Nishio K, Akai Y, Murao Y et al. Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock: Crit Care Med. 1997, 25(6):953-7

Zhou M, Chaudry IH, Wang P. Adrenomedullin is upregulated in the heart and aorta during the early and late stages of sepsis. Biochim Biophys Acta. 1999 , 24;1453(2):273-83.

Zhou M, Chaudry IH, Wang P. Adrenomedullin is upregulated in the heart and aorta during the early and late stages of sepsis. Biochim Biophys Acta. 1999 , 24;1453(2):273-83.

• LPS: stimulating AM production

Control LPS0

100

200

300 **

seru

m A

M (

fmo

l/m

l)

Jean Marc Hyvelin, Qixian Shan, Jean Pierre Bourreau. Adrenomedullin: a cardiac depressant factor in septic shock. J Card Surg, 2002, 17(4):328-35

Jean Marc Hyvelin, Qixian Shan, Jean Pierre Bourreau. Adrenomedullin: a cardiac depressant factor in septic shock. J Card Surg, 2002, 17(4):328-35

Acute Escherichia coli bacteremia stimulated adrenomedullin tissue levels in the lung, spleen, and small intestine. *P < 0.05 versus saline controls.

Acute Escherichia coli bacteremia stimulated adrenomedullin tissue levels in the lung, spleen, and small intestine. *P < 0.05 versus saline controls.

Matheson PJ, Mays MP, Hurt RT et al. Adrenomedullin is increased in the portal circulation during chronic sepsis in rats. Am J Surg, 2003, 186 (5):519-25Matheson PJ, Mays MP, Hurt RT et al. Adrenomedullin is increased in the portal circulation during chronic sepsis in rats. Am J Surg, 2003, 186 (5):519-25

• Proinflammatory cytokines (e.g. TNF-, IL-1): pa

rticipating in the overproduction of AM

Quantitative analysis of AM transcripts in cultured cardiac myocytes (A) and nonmyocytes (B) with or without treatment with IL-1ß or TNF . Open bars, Control; solid bars, IL-1ß; hatched bars, TNF. *P < 0.05; **P < 0.01; ***P < 0.001 (compared with the control).

Quantitative analysis of AM transcripts in cultured cardiac myocytes (A) and nonmyocytes (B) with or without treatment with IL-1ß or TNF . Open bars, Control; solid bars, IL-1ß; hatched bars, TNF. *P < 0.05; **P < 0.01; ***P < 0.001 (compared with the control).

Time course of the effects of IL-1ß ( ) and TNF ( ) on the secretion of ir-AM in cultured cardiac myocytes (A) and nonmyocytes (B). Control ( ) indicates basal secretion. *P < 0.05; ***P < 0.001 (compared with the control).

Takeshi Horio, Toshio Nishikimi, Fumiki Yoshihara et al. Production and Secretion of Adrenomedullin in Cultured Rat Cardiac Myocytes and Nonmyocytes: Stimulation by Interleukin-1ß and Tumor Necrosi

s Factor- Endocrinology, 1998, 139(11): 4576-80

Takeshi Horio, Toshio Nishikimi, Fumiki Yoshihara et al. Production and Secretion of Adrenomedullin in Cultured Rat Cardiac Myocytes and Nonmyocytes: Stimulation by Interleukin-1ß and Tumor Necrosi

s Factor- Endocrinology, 1998, 139(11): 4576-80

The role of AM in the hemodynamic altera

tions during sepsis

• AM increases in cardiovascular system d

uring sepsis

• a biphasic hemodynamic response during

the progession of sepsis

• Upregulation of AM in proportion to the seve

rity of hyperdynamic state of septic shock

Correlations between the plasma concentration of adrenomedullin and cardiac index, stroke volume index, systemic vascular resistance index (SVRI), and pulmonary vascular resistance index (PVRI) in patients with septic shock.

Correlations between the plasma concentration of adrenomedullin and cardiac index, stroke volume index, systemic vascular resistance index (SVRI), and pulmonary vascular resistance index (PVRI) in patients with septic shock.

Nishio Kenji, Akai Yasuhiro, Murao Yoshinori et al. Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock. Critical care medicine, 1997, 25(6): 953-957

Nishio Kenji, Akai Yasuhiro, Murao Yoshinori et al. Increased plasma concentrations of adrenomedullin correlate with relaxation of vascular tone in patients with septic shock. Critical care medicine, 1997, 25(6): 953-957

Intracellular signaling transduction of AM

• Vasodilatory actions

Vascular relaxationVascular relaxation

cAMPcAMP Ca 2+Ca 2+on smoonth

muscle cells

on smoonth

muscle cells

on endothelial cellson endothelial cells NONO

• Actions on the h

eart

1. the negative inot

ropic effect: NO/sG

C/cGMP pathway

Influence of L-NMMA on negative inotropic effect of AMInfluence of L-NMMA on negative inotropic effect of AM

Effects of AM on myocyte contraction and intracellular calcium. Effects of AM on myocyte contraction and intracellular calcium.

Modification of effect of AM by methylene (Meth.) blue

Modification of effect of AM by methylene (Meth.) blue

Effects of AM on intracellular cGM Effects of AM on intracellular cGM

Hiroshi Ikenouchi, Kenji Kangawa, Hisayuki Matsuo et al. Negative Inotropic Effect of Adrenomedullin in Isolated Adult Rabbit Cardiac Ventricular Myocytes. Circulation, 1997, 95(9), 2318-2324

Hiroshi Ikenouchi, Kenji Kangawa, Hisayuki Matsuo et al. Negative Inotropic Effect of Adrenomedullin in Isolated Adult Rabbit Cardiac Ventricular Myocytes. Circulation, 1997, 95(9), 2318-2324

2. the positive inotropic effect: (1) cAMP-independent

mechanism•

A

A, Effect of ADM alone or in combination with H-89, a protein kinase A inhibitor, on developed tension (DT) in isolated perfused, paced rat hearts; B, Effect of ADM and isoproterenol (ISO) on cAMP levels of the perfused hearts.

A, Effect of ADM alone or in combination with H-89, a protein kinase A inhibitor, on developed tension (DT) in isolated perfused, paced rat hearts; B, Effect of ADM and isoproterenol (ISO) on cAMP levels of the perfused hearts.

A, Effect of ADM and PAMP on developed tension (DT) in isolated perfused, paced rat hearts; B, Effect of ADM alone or in combination with CGRP8–37, a CGRP receptor antagonist, on DT in isolated perfused, paced rat hearts.

A, Effect of ADM and PAMP on developed tension (DT) in isolated perfused, paced rat hearts; B, Effect of ADM alone or in combination with CGRP8–37, a CGRP receptor antagonist, on DT in isolated perfused, paced rat hearts.

Szokodi I, Kinnunen P, Tavi P et al. Evidence for cAMP-independent mechanisms mechanisms mediating the effects of adrenomedullin, a new inotropic peptide. Circulation, 1998, 97(11): 1062-1070

Szokodi I, Kinnunen P, Tavi P et al. Evidence for cAMP-independent mechanisms mechanisms mediating the effects of adrenomedullin, a new inotropic peptide. Circulation, 1998, 97(11): 1062-1070

(2) cAMP-dependent pathway(2)

Dose-dependent effects of adrenomedullin on the force of rat papillary muscle.Dose-dependent effects of adrenomedullin on the force of rat papillary muscle.

Dose-dependent effects of adrenomedullin on intracellular cAMP level in rat papillary muscle.Dose-dependent effects of adrenomedullin on intracellular cAMP level in rat papillary muscle.

Ihara T, Ikeda U, Tate Y et al. Positive inotropic effects of adrenomedullin on rat papillary muscle. Eur. J. Pharmacol, 2000, 309: 167-172Ihara T, Ikeda U, Tate Y et al. Positive inotropic effects of adrenomedullin on rat papillary muscle. Eur. J. Pharmacol, 2000, 309: 167-172

3. a dual inotropic effect of AM:

A

0.0 0.5 1.0 1.5 2.0

0

25

50

75

100

control

+ ADM (1-52)

Time (sec.)

% i

ncr

ease

(340

/380

)

0.0 0.5 1.0 1.5 2.0

0

25

50

75

100

+ ADM (1-52)

control

Time (sec.)

B

0

5

10

15

control

ADM(1-52)

ADM(1-52)+ADM(22-52)

positive effect negative effect

C

*

*

% c

ell

shor

ten

ing

A. Positive effect B. negative effect of ADM on Ca2+ transient

C. Positive and negative effect of ADM on cell shortening in response to electrical-field stimulation in normal myocytes at 30 mins and at >1 hour.

Pretreatment with ADM (22-52) abolished both the effects. *P< 0.05 vs control; P< 0.05 vs ADM (1-52) group.

A. Positive effect B. negative effect of ADM on Ca2+ transient

C. Positive and negative effect of ADM on cell shortening in response to electrical-field stimulation in normal myocytes at 30 mins and at >1 hour.

Pretreatment with ADM (22-52) abolished both the effects. *P< 0.05 vs control; P< 0.05 vs ADM (1-52) group.

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullinIs adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullinIs adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

A. The amplitude of the calcium transient elicited in myocytes isolated from LPS treated rats by electrical-field stimulation was significantly decreased as compared to transients obtained in myocytes isolated from control rats. ADM(22-52) abolished this effect of LPS on the myocytes;

B. B. In LPS- treated cells the cell shortening was markedly decreased and incubation with of ADM (22-52) or anti-ADM (rat)-IgG restored the cell contractility

A. The amplitude of the calcium transient elicited in myocytes isolated from LPS treated rats by electrical-field stimulation was significantly decreased as compared to transients obtained in myocytes isolated from control rats. ADM(22-52) abolished this effect of LPS on the myocytes;

B. B. In LPS- treated cells the cell shortening was markedly decreased and incubation with of ADM (22-52) or anti-ADM (rat)-IgG restored the cell contractility

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullinIs adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullinIs adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

4. the negative effect of AM on the LPS-treated rat isolate

d myocytes

A

0

50

100

150

*

sham controlLPS treated

LPS+Indomethacin (25 M)LPS+SC-236 (10M)

3

40/3

80 (

% c

ontr

ol)

C

0

5

10

15

sham controlLPS controlLPS+Indomethacin (25 M)LPS+SC236 (10 M)

*

NS

% c

ell

shor

ten

ing

B

0

50

100

150

sham control

LPS treatedLPS+Tranylcypromine (100 M)LPS+SQ 29548 (10 M)

* *

NS

3

40/3

80 (

% c

ontr

ol)

D

0

5

10

15

sham controlLPS treatedLPS+Tranylcypromine (100 M)LPS+SQ 29548 (10 M)

% c

ell

shor

ten

ing

* *

NS

Figure 6

Effect of indomethacin (A, C), SC-23

6 (A, C), tranylcypromine (B, D) and

SQ 29548 (B, D) on decreased Ca2+

transient (A, B) and cell shortening

(C, D) in LPS treated rat ventricular

myocytes. *P< 0.05 vs control; P< 0.

05 vs LPS treated cells.

Effect of indomethacin (A, C), SC-23

6 (A, C), tranylcypromine (B, D) and

SQ 29548 (B, D) on decreased Ca2+

transient (A, B) and cell shortening

(C, D) in LPS treated rat ventricular

myocytes. *P< 0.05 vs control; P< 0.

05 vs LPS treated cells.

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullin. Is adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

Shivani Mittra, Jean- Marc Hyvelin, Qixian Shan et al. Role of cyclo-oxygenase in the ventricular effects of adrenomedullin. Is adrenomedullin a double-edged sword in sepsis? American Journal of Physiology, 2004 (accepted)

Modulation of AM in sepsis

• an anti-inflammatory factor

• Early producion of AM prolongs the hyperdynam

ic and hypercardiovascular response during sep

sis

• Protective against circulation collapse, organ da

mage

Future area of research

• Whether AM downregulates proinflammatory c

ytokines

• Whether AM gene delivery prolongs the hyper

dynamic response in sepsis

• Whether one the mechanisms responsible for

the protective effects by AM is due to an incre

ase in endothelium-derived NO release