Sub theme 4.6
Organ Transplantation


Goals of research: general outline
Scientific achievements
Future plans: special goals and approach
Running projects
Associated staff

Workgroup leaders   Department
Prof.dr.  C.C.  Baan   Internal Medicine
Dr.  T.  van  Gelder   Internal Medicine
prof.dr.  J.N.M.  IJzermans   Surgery
dr.  L.J.W.  van der  Laan   Surgery
Dr.  S.N.   de  Wildt   Pediatrics Surgery

Goals of research: general outline

Organ transplantation is the treatment of choice for end stage organ failure. Although one year results are excellent, two major problems remain; Long-term survival of organ grafts has still not reached its full potential, and the shortage of suitable donor organs is still increasing.

Long-term graft survival is significantly hampered by chronic transplant dysfunction (CTD). This still poorly defined way of untreatable functional deterioration of an organ following transplantation accounts for approximately 30 percent of graft loss in the first 5 years after transplantation. The histomorphological hallmark of CTD in all parenchymal allografts is allograft vasculopathy. This process is characterized by neo-intima formation due to migration and proliferation of vascular smooth muscle cells into the intima.

Cold storage of organ transplants induces ischemia-reperfusion (I/R) injury after transplantation which is associated with primary non-function and decreased long-term graft survival. Inflammation plays a major role in the pathophysiology of renal ischemic injury. The initial ischemic injury results in production of reactive oxygen species (ROS), up-regulation of adhesion molecules on activated endothelium and release of cytokines. Leukocytes, recruited by chemokines and pro-inflammatory cytokines, potentiate injury by generating more ROS and eicosanoids, thereby further enhancing inflammation.

Since I/R injury is a risk factor for both immediate and long-term graft dysfunction not only in kidney transplants, but also in liver, heart, and lung grafts, The aim of our laboratory is to study surgical, genetic, physiological and pharmacological ways to prevent or ameliorate ischemia-reperfusion injury. These studies are coordinated by dr. RWF de Bruin.

Scientific achievements

Pulmonary ischemia-reperfusion injury

Using our previously developed model of left lung ischemia, we studied two important questions that had not been addressed properly. The question whether I/R injury exclusively results in acute graft failure was difficult to answer, due to the lack of a long-term experimental model. In addition, the long-term effects of I/R injury of the lung were unclear and a description of the immunological changes over time was missing. We performed a detailed study of the immunological changes in lung tissue and broncho-alveolar lavage fluid until 90 days after induction of ischemia, and showed that I/R injury is an independent risk factor for the development of acute graft failure, and resulted in progressive deterioration of lung function and architecture, leading to extensive immunopathological and functional abnormalities up to 3 months after reperfusion.

We showed that intratracheal administration of surfactant significantly reduced acute I/R injury in the lung. Rats were randomised to receive intratracheally administered surfactant or no treatment. Surfactant treatment before induction of I/R injury improved survival, lung compliance and PaO2. It also reduced protein leakage and prevented an increase in the SA/LA ratio of surfactant in the first week following I/R injury. Subsequently, we showed that surfactant pre-treatment of the lung also ameliorated the long-term immunological and functional changes as described above.

Pharmacological treatment

Immune regulation using pharmacologically active peptides

Based on a report showing that an oligopeptide related to the primary structure of the hormone human Chorionic Gonadotropin (hCG) reduced mortality in a model of lipopolysaccharide induced systemic inflammatory response syndrome, we investigated the effect of similar synthetic peptides in a renal ischemia-reperfusion model. We found that several small peptides, consisting of 3-4 amino acids, were able to significantly reduce mortality and improve kidney function in this model. This protection was associated with a significantly lower induction of adhesion molecules, influx of neutrophils, and decrease of apoptotic cells, whereas tubular epithelial cell proliferation was significantly increased at 24 h post-reperfusion. Serum cytokine levels were significantly decreased at 24 h post-reperfusion.  

Hemorrhagic shock induced by severe blood loss induces systemic I/R injury following resuscitation of the patient. We investigated whether administration of hCG-related oligopeptides during hemorrhagic shock was able to attenuate the inflammatory response in a rat model. Peptide treatment prevented systemic release of TNF-α and IL-6 and was associated with reduced TNF- α, IL-6, and E-selectin mRNA transcript levels in the liver. Treatment prevented neutrophil infiltration in the liver and was associated with reduced liver damage. Our data suggest that hCG-related oligopeptides have therapeutic potential in the treatment of renal I/R injury as well as hemorrhagic shock.

Pharmacological donor pre-treatment

We tested whether the major hallmark of chronic organ transplant dysfunction (CTD), namely transplant arteriosclerosis, can be reduced by pre-treatment of the organ donor with immunosuppressive agents, using a rat allogeneic aorta transplantation model. We found that aorta allografts pre-treated with tacrolimus, showed significantly less arteriosclerosis compared to untreated controls. Although we have not fully elucidated the mechanism inducing this effect, our data suggest that pre-treatment of the donor may be a novel way to improve long-term transplant results.

Genetic amelioration of ischemia-reperfusion injury

Since the histologic changes of chronic transplant dysfunction in the kidney in part overlap with those of normal renal aging, we asked whether accelerated aging mechanisms contribute to the pathology of CTD. We used Cockayne syndrome mice to study this. Cockayne syndrome (Cs) is a segmental progeria (accelerated aging syndrome) with inborn defects in DNA repair mechanisms. Cs mice are thought to be hypersensitivity to endogenous oxidative DNA damage. We tested the sensitivity to acute oxidative stress induced by renal ischemia-reperfusion injury. Surprisingly, we found Cs mice to be less susceptible than wild type animals. Renal failure-related mortality was significantly reduced in Csb(-/-) mice, kidney function was improved and proliferation was significantly higher in the regenerative phase following ischemic injury. This suggests that unrepaired DNA damage may elicit an adaptive response that contributes to the observed resistance to I/R injury in these mice.

Surgical aspects

Minimally invasive donor nephrectomy in living donors is now the surgical standard. During the introduction of this technique it was suggested that the kidney graft could be ischemically damaged due to the increased intra-abdominal pressure created by the pneumoperitoneum, and the longer retrieval time. We developed a minimally invasive (laparoscopic) model in the rat, and showed that laparoscopic donor nephrectomy was not associated with impaired graft function following transplantation compared to classic open nephrectomy.

Xenotransplantation

Islet of Langerhans transplantation is a curative treatment option for diabetes mellitus type I. Due to the large number of islets that is needed to perform a successful transplantation, we focussed our research on pig donors, since the supply of pig pancreata (and also other organs) is limitless. One of the major hurdles in xenotransplantation is the presence of anti –αGal antibodies in human recipients. We investigated the development of anti-pig antibodies in blood of humans and baboons. We showed that cytotoxic anti-αGal antibodies develop during the first 3 months of life, whereas cytotoxic anti –non αGal antibodies are minimal or absent during the first year of life. Thus early infancy may be a period in which xenogeneic transplantation would be feasible.

Future plans: special goals and approach

Future investigations will focus on the mechanism of action of immunoregulatory peptides as well as on their application in other surgical inflammatory conditions such as sepsis and post-surgical inflammation.

The physiology of the protective response observed in Cs (-/-) mice shows similarities with the observed increased stress resistance in models of dietary restriction. We hypothesise that these responses share a common biological basis, and aim to investigate the effect of dietary restriction in models of acute oxidative damage, and to explore the mechanistic basis of protection in these models.

Most recent publications
  1. Van der Kaaij NP, Haitsma JJ, Kluin J, Lambrecht BN, Lachmann B, de Bruin RWF, Bogers AJJC. Surfactant pre-treatment ameliorates ischemia reperfusion injury of the lung. Eur J Cardiothorac Surg 2005; 27: 774- 782.
  2. Lind MY, Hazebroek EJ, Bajema IM, Bonthuis F, Hop WC, de Bruin RW, IJzermans JN. Effect of prolonged warm ischemia and pneumoperitoneum on renal function in a rat syngeneic kidney transplantation model. Surg Endosc. 2006 ; 20 : 1113-1118.
  3. Rood PP, Tai HC, Hara H, Long C, Ezzelarab M, Lin YJ, van der Windt DJ, Busch J, Avares D, IJzermans JN, Wolf RF, Manji R, Baily L, Cooper DK. Late onset of development of natural anti-non Gal antibodies in infant humans and baboons : implications for xenotransplantation in infants. Transplant Int 2007; 20:1050-1058.
  4. NP van der Kaaij, J Kluin, J Haitsma, MA den Bakker, BN Lambrecht, B Lachmann, RWF de Bruin*, AJJC Bogers*. Ischemia of the lung causes extensive long-term pulmonary injury: an experimental study. Resp Res 2008; 9: 28-44. * Shared senior authorship.
  5. Van der Windt DJ, Echeverri GJ, IJzermans JN, Cooper DK. The choice of anatomical site for islet transplantation. Cell Transplant 2008; 17: 1005-1014.
  6. vd Kaaij NP, Kluin J, Haitsma JJ, den Bakker MA, Lambrecht BN, Lachmann B, de Bruin RW*, Bogers AJCC*. Surfactant pretreatment decreases long-term damage after ischemia-reperfusion injury of the lung . Eur J Cardio-Thoracic Surg 2009, 35: 304-12. * Shared senior authorship.
  7. Khan NA, Susa D, van den Engel S, Huisman TM, Ameling MH, Roest HP, IJzermans JNM, Dik WA, Benner R*, de Bruin RWF*. Inhibition of renal ischemia-reperfusion injury by synthetic oligopeptides related to human chorionic gonadotropin. Nephrol Dial Transplant, 2009, 24:2701-2708. * Shared senior authorship.

  8. H Rogier van den Berg, NA Khan, M van der Zee, F Bonthuis, JNM IJzermans, WA Dik, RWF de Bruin*, R Benner*. Synthetic oligopeptides related to the [beta]-subunit of human chorionic gonadotropin attenuate inflammation and liver damage after (trauma) hemorrhagic shock and resuscitation. Shock 2009; 31: 285-291. * Shared senior autorship.

  9. D Susa, S van den Engel, LCA van Damme, HP. Roest, R Krams, JNM IJzermans, RWF de Bruin. Donor pretreatment with Tacrolimus reduces transplant vasculopathy. Pharm Res 2009; 59: 273-278.
  10. Susa D, Mitchell JR, Verweij M, Roest HP, van den Engel S, Bajema IM, Molenbeek P, Mangundap K, IJzermans JNM, Hoeijmakers JHJ, de Bruin RWF. Transcription-coupled repair deficiency protects against renal ischemia reperfusion injury. Aging Cell, 2009; 8: 192-200.