Poly-ADP-ribose polymerase inhibition reduces mesenteric injury after cardiopulmonary bypass

Strategies for Pharmacological Organoprotection during Extracorporeal Circulation Targeting Ischemia-Reperfusion Injury

Surgical correction of congenital cardiac malformations or aortocoronary bypass surgery in many cases implies the use of cardiopulmonary-bypass (CPB). However, a possible negative impact of CPB on internal organs such as brain, kidney, lung and liver cannot be neglected. In general, CPB initiates a systemic inflammatory response (SIRS) which is presumably caused by contact of blood components with the surface of CPB tubing. Moreover, during CPB the heart typically undergoes a period of cold ischemia, and the other peripheral organs a global low flow hypoperfusion. As a result, a plethora of pro-inflammatory mediators and cytokines is released activating different biochemical pathways, which finally may result in the occurrence of microthrombosis, microemboli, in depletion of coagulation factors and haemorrhagic diathesis besides typical ischemia-reperfusion injuries. In our review we will focus on possible pharmacological interventions in patients to decrease negative effects of CPB and to improve post-operative outcome with regard to heart and other organs like brain, kidney, or lung.

Organ-protective effects on the liver and kidney by minocycline in small piglets undergoing cardiopulonary bypass

Cardiopulmonary bypass (CPB) often is required for the operative correction of congenital heart defects in small infants. Unfortunately, CPB is associated with injury of inner organs such as the brain, kidney, lung, and liver. Renal failure and increase in liver enzymes are typical side effects observed after CPB. Here, we investigate whether organ protection of the kidney and liver can be achieved with the application of minocycline, which is known-besides its anti-infective effects-to act as a poly-ADP-ribose-polymerase inhibitor. Twenty-nine 4-week-old Angler Sattelschwein-piglets (8-15 kg) were divided into four groups: control group (n = 8), CPB group (n = 9), minocycline-control group (n = 6), and the minocycline-CPB group (n = 6). CPB groups were thoracotomized and underwent CPB for 120 min (cross-clamp, 90 min; reperfusion, 30 min) followed by a 90-min recovery time. The control groups also were thoracotomized but not connected to CPB. The minocycline group received 4 mg/kg minocycline before and 2 mg/kg after CPB. In the kidneys, CPB histologically resulted in widening of Bowman's capsule, and-mainly in tubules-formation of poly-ADP-ribose, nitrosylation of tyrosine-residues, nuclear translocation of hypoxia-induced factor HIF-1α, and of apoptosis-inducing factor (AIF). In addition, we found significantly less ATP in the kidney and significantly increased plasma urea and creatinine. Similar but gradually attenuated changes were found in the liver together with significantly elevated de-Ritis coefficient. These changes in the kidney and liver were significantly diminished by minocycline (except AIF in the liver which was similar in all groups). In conclusion, CPB causes damage in the kidney and-to a lower degree-in the liver, which can be attenuated by minocycline.

Poly(ADP-ribose) polymerase-1 is a key mediator of cisplatin-induced kidney inflammation and injury

Cisplatin is a commonly used chemotherapeutic drug, the clinical use of which is limited by the development of dose-dependent nephrotoxicity. Enhanced inflammatory response, oxidative stress, and cell death have been implicated in the development of cisplatin-induced nephropathy; however, the precise mechanisms are elusive. Overactivation of the nuclear enzyme poly(ADP-ribose) polymerase-1 (PARP-1) by oxidative DNA damage under various pathological conditions promotes cell death and up-regulation of key proinflammatory pathways. In this study, using a well-established model of nephropathy, we have explored the role of PARP-1 in cisplatin-induced kidney injury. Genetic deletion or pharmacological inhibition of PARP-1 markedly attenuated the cisplatin-induced histopathological damage, impaired renal function (elevated serum BUN and creatinine levels), and enhanced inflammatory response (leukocyte infiltration; TNF-α, IL-1β, F4/80, adhesion molecules ICAM-1/VCAM-1 expression) and consequent oxidative/nitrative stress (4-HNE, 8-OHdG, and nitrotyrosine content; NOX2/NOX4 expression). PARP inhibition also facilitated the cisplatin-induced death of cancer cells. Thus, PARP activation plays an important role in cisplatin-induced kidney injury, and its pharmacological inhibition may represent a promising approach to preventing the cisplatin-induced nephropathy. This is particularly exciting because several PARP inhibitors alone or in combination with DNA-damaging anticancer agents show considerable promise in clinical trials for treatment of various malignancies (e.g., triple-negative breast cancer).