The emerging application of remote ischemic conditioning in the clinical arena

Turning On Lights to Stop Neurodegeneration: The Potential of Near Infrared Light Therapy in Alzheimer's and Parkinson's Disease

Alzheimer's and Parkinson's disease are the two most common neurodegenerative disorders. They develop after a progressive death of many neurons in the brain. Although therapies are available to treat the signs and symptoms of both diseases, the progression of neuronal death remains relentless, and it has proved difficult to slow or stop. Hence, there is a need to develop neuroprotective or disease-modifying treatments that stabilize this degeneration. Red to infrared light therapy (λ = 600-1070 nm), and in particular light in the near infrared (NIr) range, is emerging as a safe and effective therapy that is capable of arresting neuronal death. Previous studies have used NIr to treat tissue stressed by hypoxia, toxic insult, genetic mutation and mitochondrial dysfunction with much success. Here we propose NIr therapy as a neuroprotective or disease-modifying treatment for Alzheimer's and Parkinson's patients.

Apoptosis-related microRNA changes in the right atrium induced by remote ischemic perconditioning during valve replacement surgery

We previously found that remote ischemic perconditioning (RIPerc) was effective in attenuating myocardial injury during cardiac surgery. Given that microRNAs (miRs) act as an important player in ischemic/reperfusion (I/R) injury and apoptosis, this study aimed to investigate whether RIPerc reduces apoptosis in atrial myocardium and which apoptosis-related miRs are involved during valve replacement surgery. Here, we demonstrated that RIPerc inhibited apoptosis in atrial myocardium during cardiac ischemia and that 17 miRs showed at least a 1.5-fold change in expression after ischemia. Of the 17 miRs, 9 miRs, including miR-1, miR-21, miR-24, and miR-195, which are related to apoptosis, exhibited different expression patterns in the RIPerc group compared with the control. Using qRT-PCR and Western blotting, we demonstrated that miR-1 and miR-195 were downregulated and that their common putative target gene Bcl-2 was upregulated in the RIPerc group. However, the differences in miR-21 and miR-24 expression, together with programmed cell death 4 (PDCD4), which is the target gene of miR-21, were not significant. These findings provide some insight into the role of miRs in the cardioprotective effects induced by RIPerc.

Protection against renal ischemia-reperfusion injury by ischemic postconditioning

Ischemia-reperfusion injury (IRI) is inevitable during transplantation. Attempts to reduce IRI have mainly focused on ways to improve hypothermic organ preservation and reduce the nephrotoxic effects of calcineurin inhibitors. Recently, it has been shown that short, repeated sequences of intermittent ischemia and reperfusion after a prolonged ischemic episode, so-called ischemic postconditioning (IPoC), reduce myocardial infarct size by approximately 40% in animal models and in humans. The principle of IPoC could be applied to every organ after ischemic injury, including kidney transplants. In fact, IPoC has demonstrated its clinical potential by reducing IRI in different organs in several animal models. In this review, we provide an overview of animal experiments on renal IRI and IPoC, demonstrating benefits with respect to organ damage and kidney function. We propose potential mechanisms by which IPoC protects against IRI. However, thus far, no human trials investigating IPoC in transplantation have been performed. Such clinical studies are needed to establish whether a simple procedure such as IPoC can improve the outcomes of human organ transplantation.