Diazepam ameliorated myocardial ischemia-reperfusion injury via inhibition of C-C chemokine receptor type 2/Tumor necrosis factor-alpha/Interleukins and Bcl-2-associated X protein/Caspase-3 pathways in experimental rats

New therapeutic concepts against ischemia-reperfusion injury in organ transplantation

INTRODUCTION

Ischemia-reperfusion injury (IRI) involves a positive amplification feedback loop that stimulates innate immune-driven tissue damage associated with organ procurement from deceased donors and during transplantation surgery. As our appreciation of its basic immune mechanisms has improved in recent years, translating putative biomarkers into therapeutic interventions in clinical transplantation remains challenging.

AREAS COVERED

This review presents advances in translational/clinical studies targeting immune responses to reactive oxygen species in IRI-stressed solid organ transplants, especially livers. Here we focus on novel concepts to rejuvenate suboptimal donor organs and improve transplant function using pharmacologic and machine perfusion (MP) strategies. Cellular damage induced by cold ischemia/warm reperfusion and the latest mechanistic insights into the microenvironment's role that leads to reperfusion-induced sterile inflammation is critically discussed.

EXPERT OPINION

Efforts to improve clinical outcomes and increase the donor organ pool will depend on improving donor management and our better appreciation of the complex mechanisms encompassing organ IRI that govern the innate-adaptive immune interface triggered in the peritransplant period and subsequent allo-Ag challenge. Computational techniques and deep machine learning incorporating the vast cellular and molecular mechanisms will predict which peri-transplant signals and immune interactions are essential for improving access to the long-term function of life-saving transplants.

Plantamajoside alleviates hypoxia-reoxygenation injury through integrin-linked kinase/c-Src/Akt and the mitochondrial apoptosis signaling pathways in H9c2 myocardial cells

Myocardial ischemia-reperfusion injury(MIRI) is one of the common complications after myocardial infarction surgery, Oxidative stress is among the main mechanisms of myocardial ischemia-reperfusion injury. Plantamajoside (PMS), the main effective ingredient in the genus Plantain, has been reported to possess an antioxidation, anti-inflammatory and anti-apoptosis role. However, whether PMS can attenuate myocardial ischemia-reperfusion injury is not yet known. Herein, we explored the effects of PMS on hypoxia-reoxygenation (H/R) injury in H9c2 cardiomyocytes and the underling molecular mechanisms of the treatment. Network pharmacological analysis screened the top 31 key genes in the treatment of MIRI disease treated with PMS, and the result of molecular docking further illustrated the roles that the PMS play in the treatment of MIRI through its interference with integrin-linked kinase (ILK) target protein. PMS was not cytotoxic in the concentration range of 5-40 μM and increased cell survival after H/R injury in a concentration-dependent manner without affecting proliferation or growth. PMS significantly reduced the levels of lactate dehydrogenase, malonic dialdehyde, reactive oxygen species and cell apoptosis, and increased soperoxide dismutase activity compared with those of the H/R injury group. PMS promoted the protein and mRNA expression of ILK and Bcl-2, the protein expression of p-Akt, and reduced the protein and mRNA expression of Bax, Caspase-3, and Cytochrome c, the protein expression of p-c-Src. PMS has protective effects against H/R injury in H9c2 cells, and its protective mechanism may be related to reactive oxygen species clearance, activation of the ILK/c-Src/Akt pathway and inhibition of the mitochondrial apoptosis.

Knockdown of interleukin-6 plays a neuroprotective role against hypoxia-ischemia in neonatal rats via inhibition of caspase 3 and Bcl-2-associated X protein signaling pathway

This study aimed to investigate the role of interleukin-6 (IL-6) in the pathogenesis of neonatal hypoxic-ischemic encephalopathy (NHIE). Sprague-Dawley (SD) rats were used for the establishment of hypoxic-ischemic (HI) model. The Zea-Longa scoring was used to evaluate the extent of the neurological deficits. Triphenyl tetrazolium chloride (TTC) staining was used to measure the volume of infarction in the brain following HI protocol. The expression of IL-6 in the cortex and/or hippocampus at multiple time points after HI was examined by immunohistochemistry, western blotting and immunofluorescence. Moreover, small interfering RNAs (siRNA) were used to inhibit the expression of IL-6 in-vitro and in-vivo, and the concomitant expression of the Bcl-2 associated X protein (BAX) and caspase 3 was also measured. HI induced a significant brain damage, and these pathological changes were accompanied by IL-6 upregulation which was found localized in cortical neurons. The inhibition of IL-6 expression fostered neuronal and axonal growth, and a reduction in cellular apoptosis in cortical neuronal cultures, and cortex and hippocampus of neonatal rats. The expression of apoptotic markers such as BAX and caspase 3 was closely associated with IL-6. Downregulation of IL-6 could ameliorate HI-induced deficiencies by mediating the expression of caspase 3 and BAX.

Effects of swimming training on myocardial protection in rats

Swimming is important for promoting and maintaining health, as it can increase the efficiency of the cardiovascular system and decrease the occurrence of cardiovascular diseases. The objective of the present study was to examine whether swimming training could decrease myocardial injury in rats caused by myocardial ischemia/reperfusion (I/R). Sprague-Dawley rats were randomized into four groups, namely the Sham, coronary artery occlusion, swimming training and ischemic preconditioning (IPC) groups. Myocardial I/R was induced in anesthetized male Sprague-Dawley rats by a 40-min occlusion followed by a 3-h reperfusion of the left anterior descending coronary artery. The rats were sacrificed after surgery and their hearts were examined. The results demonstrated that the number of TUNEL-positive nuclei and degree of caspase-3 activation were both significantly increased in the myocardium following myocardial I/R in rats, indicating increased cardiomyocyte apoptosis. On the other hand, swimming training decreased the serum levels of creatine phosphokinase, lactate dehydrogenase and cardiac troponin I, and was associated with reduced histological damage and myocardial infarct size. Furthermore, swimming training also reduced TNF-α levels, caspase-3 activation and enhanced Bcl-2 activation, which decreased the number of apoptotic cells in the myocardium. The findings of the present study showed that swimming training and IPC could similarly decrease myocardial injury following myocardial I/R, and may therefore be used as exercise training to effectively prevent myocardial injury.