The interleukin-6/interleukin-6-receptor system is activated in donor hearts.
OBJECTIVE
To assess the potential of the donor heart to respond to interleukin-6 (IL6), the present study investigated the expression of IL6 receptor components in the myocardium of donor hearts before transplantation.


BACKGROUND
Donor heart dysfunction early after transplantation has been associated with the cytokine storm after donor brain death. Proinflammatory cytokines are thought to play a central role in this process. Interleukin-6 is of specific interest because it has been associated with cardiac allograft dysfunction and is related to an impaired prognosis. Its action requires expression of the specific IL6 receptor (IL6R), and the common signal transducer of the IL6 family glycoprotein 130 (gp130) in the donor heart.


METHODS
The activation of IL6, IL6R and gp130 messenger ribonucleic acid (mRNA) and protein was studied via reverse transcription-polymerase chain reaction (RT-PCR) and immunohistology in donor hearts (n = 6) and compared with patients undergoing evaluation of ventricular arrhythmias (control, n = 9) or with advanced heart failure (n = 20).


RESULTS
Messenger RNA of IL6, IL6R and gp130 was strongly expressed in all chambers of donor hearts, whereas right ventricles of control patients did not show any expression (donor vs. control: p < 0.005). Right ventricles of failing hearts showed IL6, IL6R and gp130 mRNA levels comparable with those found in donor hearts. Immunohistochemistry paralleled the RT-PCR data on the protein level. While IL6 was mainly expressed by myocytes, both receptor components were preferentially found mainly on interstitial cells.


CONCLUSIONS
The expression of the IL6 receptor components in the donor heart before transplantation establishes the condition sine qua non for the response of the donor heart to circulating IL6. This mechanism may explain the close association of elevated IL6 serum levels to acute cardiac allograft dysfunction in the early perioperative period.
Plenz
Gabriele
G
Department of Cardiothoracic Surgery, Muenster University, Muenster, Germany. plenz@uni-muenster.de
Eschert
Heike
H
Erren
Michael
M
Wichter
Thomas
T
Böhm
Michael
M
Flesch
Markus
M
Scheld
Hans H
HH
Deng
Mario C
MC
D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood; D050822:Cytokine Receptor gp130; D006321:Heart; D016027:Heart Transplantation / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009206:Myocardium / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism*; D019947:Receptors, Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014019:Tissue Donors; D018754:Ventricular Dysfunction / Q000097:blood / Q000175:diagnosis*
D015703:Antigens, CD; D015415:Biomarkers; C494199:IL6ST protein, human; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D019947:Receptors, Interleukin-6; D050822:Cytokine Receptor gp130