Renal ischemia-reperfusion injury (IRI) is one of the causes of acute kidney injury. Annexin A5 (AnxA5), a calcium-dependent cell membrane-binding protein, shows protective effects in various organ IRI models. This study explored the therapeutic effect of exogenous AnxA5 monomer protein on renal IRI and its potential mechanism of action.

Different doses of AnxA5 were injected intravenously to treat bilateral renal IRI in SD rats. This model confirmed the protective effects of AnxA5 on kidney structure and function. In vitro, HK-2 cells were subjected to hypoxia for 12 h, followed by restoration of normal oxygen supply to simulate IRI. In vitro experiments demonstrated the mechanism of action of AnxA5 by measuring cellular activity and permeability. A comparison of the mutant AnxA5 protein M23 and the application of a calcium-free culture medium further validated the protective effect of AnxA5 by forming a network structure.

Exogenous AnxA5 monomers prevented renal IRI by binding to the damaged renal tubular epithelial cell membrane, forming a two-dimensional network structure to maintain cell membrane integrity, and ultimately prevent cell death.

As the incidence of ischemia-reperfusion (I-R) injury has substantially increased, there is a pressing need to develop effective strategies to treat this global health issue. I-R injury can affect all organs and is associated with high morbidity and mortality rates. Pathological settings such as myocardial infarction, stroke, hemorrhagic shock, and solid organ transplant are particularly prone to cause I-R injury. Ischemia (hypoxia) and/or reperfusion (reoxygenation) induces various forms of cellular and structural damage. A major cause of damage is local inflammatory responses, which may spread to produce more advanced systemic inflammation. Management of I-R injury relies primarily on supportive measures, as specific treatment strategies are lacking. Extracellular vesicles (EVs) are cell-secreted nano-scale structures containing various biomolecules involved in cell communication and multiple physiological processes. EVs derived from certain cell types have been shown to exhibit anti-inflammatory, antioxidant, and angiogenic properties. This review provides an overview of EV-based therapeutics for I-R injury in kidneys, liver, heart, lungs, and brain. Additionally, the mechanisms by which EVs protect against I-R injury are discussed. Promising preclinical findings highlight the potential clinical use of EVs for I-R injury.

Non-arteritic posterior ischemic optic neuropathy (NA-PION) is a disorder of reduced blood flow to the retrobulbar optic nerve. There is usually an acute loss of visual acuity and field. Previous studies have noted an improvement in visual acuity and in ocular and retrobulbar blood flow with the use of a potent vasodilator of the microcirculation, prostaglandin E1 (PGE1), and steroids. The current report describes immediate improvement in the visual fields and visual acuity in a patient with NA-PION treated with intravenous PGE1 and steroids 66 hours after onset. An 89-year-old white female was first seen in December 2016 with a sudden loss of vision in the right eye. After a complete eye exam and visual fields, the patient was diagnosed with NA-PION. Treatment was immediately started with steroids and intravenous PGE1. This was repeated once again the next morning. Visual acuity in the right eye improved from 1/10 + 1 to 7/10 + 3 at 5 days. The mean deviation of the visual field improved from - 7.10 decibels (dB) with a central scotoma of - 22 dB to - 2.97 dB with a central scotoma of - 19 dB. After 2 weeks, her visual acuity was 7/10 + 1 and visual field testing of the right eye revealed a mean deviation of - 2.54 dB with a central scotoma of - 9 dB. The left eye was unchanged. In cases of NA-PION, PGE1 and steroids should be considered to immediately restore blood flow to help improve visual acuity and visual fields.

Non-arteritic posterior ischemic optic neuropathy (NA-PION) is a disorder involving reduced blood flow to the retrobulbar portion of the optic nerve. This disorder usually develops acutely, and research has suggested that high-dose steroid therapy soon after the onset of visual loss can result in significant visual improvement. This treatment, however, is not universally successful. The addition of a potent vasodilator could help to restore ocular blood flow. This case report describes the use of prostaglandin E1 (PGE1), a powerful vasodilator of the microcirculation, to treat three separate episodes of NA-PION over five years in the same patient. A 68-year-old white male was first seen in June 2009 with NA-PION in the left eye, and the condition was treated with steroids and PGE1. The patient had a subsequent episode in July 2010 that was treated with steroids and PGE1 and another in May 2014 that was treated with PGE1 alone. Visual acuity improved from 4/10 to 11/10 in 2009, from 4/10 to 11/10 in 2010, and from 5/10 to 10/10 in 2014. No complications due to the use of PGE1 were noted. PGE1 should be considered as a treatment for NA-PION to immediately restore blood flow and potentially improve vision.

Osthole, the main bioactive compounds isolated from the traditional Chinese medical herb broad Cnidium monnieri (L.) cusson, has been shown to exert spectrum of pharmacologic activities. The aim of this study was to investigate the potential neuroprotective effects of osthole against spinal cord ischemia-reperfusion injury in rats.

Osthole was administrated at the concentration of 0.1, 1, 10, 50, or 200 mg/kg (intraperitoneally) 1 h before spinal cord ischemia. The effects on spinal cord injury were measured by spinal cord water content, infarct volume, hematoxylin and eosin staining, and neurologic assessment. Mitochondria were purified from injured spinal cord tissue to determine mitochondrial function.

We found that treatment with osthole (10 and 50 mg/kg) significantly decreased spinal cord water content and infarct volume, preserved normal motor neurons, and improved neurologic functions. These protective effects can be also observed even if the treatment was delayed to 4 h after reperfusion. Osthole treatment preserved mitochondrial membrane potential level, reduced reactive oxygen species production, increased adenosine triphosphate generation, and inhibited cytochrome c release in mitochondrial samples. Moreover, osthole increased mitochondria respiratory chain complex activities in spinal cord tissue, with no effect on mitochondrial DNA content and the expression of mitochondrial-specific transcription factors.

All these findings demonstrate the neuroprotective effect of osthole in spinal cord ischemia-reperfusion injury model and suggest that oshtole-induced neuroprotection was mediated by mitochondrial biogenesis-independent inhibition of mitochondrial dysfunction.

Arteritic anterior ischemic optic neuropathy (AAION) is an acute ischemia of the posterior ciliary arteries and/or ophthalmic artery due to inflammation. Therapy is immediate intervention with systemic steroids, especially to protect against vision loss in the other eye. The addition of a potent vasodilator to the steroids could help restore ocular blood flow and improve visual acuity. The objective of the current report was to present the use of prostaglandin E(1) (PGE(1)) - a powerful vasodilator of the microcirculation - in the treatment of AAION. Two patients with AAION were treated with intravenous steroids and PGE(1). The visual acuity improved from 4/50 (less than 20/200) to 6/10 (20/35) in one patient and from 1/50 (20/400) to 1/10 (20/200) in the second patient. The visual fields in both patients maintained small central islands of vision. No complications due to the use of PGE(1) were seen. Intravenous PGE(1) should be considered in addition to steroids in cases of AAION to immediately restore blood flow to the optic nerve and improve visual acuity while the steroids reduce the inflammation.

Intravenous prostaglandin E1 and oral corticosteroids were used to treat the ischaemic phase of a non-arteritic posterior ischaemic optic neuropathy with immediate visual improvement. Non-arteritic posterior ischaemic optic neuropathy is a disorder of reduced blood flow to the retrobulbar optic nerve, usually of acute onset. It has been suggested that high-dose steroid therapy given soon after the onset of visual loss can result in significant visual improvement. This treatment, however, is not universally successful. The addition of a potent vasodilator to the corticosteroids could help restore ocular blood flow and improve visual acuity. This paper presents the use of prostaglandin E1 (PGE1), a powerful vasodilator of the microcirculation, to treat non-arteritic posterior ischaemic optic neuropathy. In this case report a 68-year-old white male with hereditary haemochromatosis was seen 8 hours after sudden loss of visual acuity in his left eye (OS) to 4/10. The diagnosis of non-arteritic posterior ischaemic optic neuropathy was made and he was immediately given oral corticosteroids. Intravenous PGE1 was given the next morning, 24 hours after the sudden loss of vision, once ischaemia of the optic nerve was confirmed by colour Doppler imaging. The visual acuity in the OS improved from 4/10 to 11/10 within 1 day. A visual field (VF) post treatment showed a peripheral scotoma without a central scotoma. At 12 months post treatment the vision OS remained 11/10. No complications due to the use of PGE1 were seen. The authors conclude that PGE1 should be considered in addition to steroids in cases of NA-PION to immediately restore blood flow to the optic nerve and improve visual acuity.

Ischemia/reperfusion injury (IRI) is a common complication after liver surgery. Approximately 10% of grafts lose function in the early stage after liver transplantation. However, there is no effective way against IRI yet. Heat shock protein 27 (HSP27), a member of the heat shock protein families, is recognized as a protective factor against liver IRI recently. Studies showed that HSP27 can lessen the induction of proinflammatory messenger, reduce neutrophil infiltration, decrease apoptosis (caspase 3 fragmentation and DNA laddering), and reduce disruption of filamentous actin. In addition, Kupffer cells inhibitor- gadolinium chloride can reduce lipid peroxidation and promote hepatocytes regeneration. Herein, we hypothesize that transfecting liver with HSP27 gene accompanied by gadolinium chloride might be a potentially novel treatment against IRI. Compared to passive defense, we firstly suggest positive protection against ischemia/reperfusion injury by hepatocytes automatically.

To present the use of 6-methylprednisolone IV and prostaglandin E1 IV, a powerful vasodilator of the microcirculation, in the treatment of a branch retinal arterial occlusion.

A 63-year-old man presented with a 3-hour history of a sudden loss of vision in the right eye. On ophthalmic examination, the diagnosis of a superior temporal branch retinal arterial occlusion was made. The patient was immediately given 40 mg of 6-methylprednisolone IV for more than 5 minutes followed by 80 μg of prostaglandin E1 with 2 milliequivalents of potassium IV for more than 3 hours. The same treatment was repeated the following morning.

The visual acuity in the right eye improved from 2/10 at presentation to 7/10 at the end of the second day of treatment. Clinically, there was a reduction of the posterior pole edema. Eleven days after treatment, the visual acuity was 9/10 with no retinal edema.

Immediate prostaglandin E1 IV and steroids should be considered in cases of recent-onset branch retinal arterial occlusion to restore retinal blood flow and improve visual acuity.

Organ dysfunction due to ischemia-reperfusion (I/R) injury is a common problem in transplant, liver, trauma, and heart surgery. I/R injury is mediated by upregulated expression of endothelial cell surface adhesion molecules and subsequent adhesion and activation of circulating leukocytes. The purpose of this study was to evaluate the effect of an intraoperative administration of FTY720 in an animal model with controlled bilateral warm kidney ischemia compared to steroids or placebo application.

Male C57BL6/J mice (n = 72, weight 25 to 30 g) were exposed to 30 minutes of bilateral kidney ischemia and followed by a 48 hour observation period. FTY720 (1 mg/kg body weight [BW]), steroids (5 mg/kg BW), or saline solution were administered. In addition, a sham-operated control group was included. At the termination of the experiments, all surviving animals were humanely killed. The impact of the various drugs on overall animal survival, timing of death, peripheral T-cell count, and T-lymphocyte infiltration in the kidneys was determined.

Following bilateral kidney I/R injury, FTY720 was associated with a significant improved animal survival (85.7%) compared with steroids (50%) or controls (42.4%). FACS analysis showed significant T-lymphocyte depletion in peripheral blood in the FTY720 but not in the other groups. T-lymphocyte tissue concentration in liver and kidney tissue did not show statistically significant differences following FTY720, steroid, or saline treatment.

FTY720, when administered intraoperatively, improved survival significantly in mice submitted to bilateral kidney ischemia but did not have any significant impact on the parenchymal T-lymphocyte infiltration in the ischemic organ.

Ischemia-reperfusion-Injury (I/RI) is a common complication in transplant-, liver-, and heart surgery. The I/RI is mediated and aggravated by different types of leukocytes such as lymphocytes, monocytes, and neutrophil granulocytes, with consecutive enlargement of the expression of adhesion molecules. This study shows an organ-protective effect of an intraoperative FTY720 administration following warm liver ischemia (Pringle's maneuver).

Male c57BL6/J mice (n = 46, body weight [BW] 25 to 30 g) were used. Either FTY720 (1 mg/kg BW), steroids (5 mg/kg BW), or physiological saline solution was administered intraperitoneally. Liver-ischemia was applied for 30 minutes with subsequent follow-up for 48 hours. At termination, all surviving animals were sacrificed. The impact of the drugs administered on long-term survival, time of death, and development of blood T-lymphocyte concentration was determined. Follow-up of T-lymphocyte concentration in peripheral blood was examined throughout FACS-analysis.

Following 30 minutes of ischemia, FTY720, but not steroid or vehicle treatment, showed a significant protective effect on long-term survival. FACS-analysis showed significant T-lymphocyte depletion in peripheral blood following FTY720 but not steroids or vehicle treatment.

The improved long-term survival following FTY720 application shown in this study might be due to a protective effect of FTY720 in prevention of I/RI. This might be mediated by the T-lymphocyte depletion shown in the FACS-analysis.

According to current literature, infective processes greatly modify both vascular hemodynamics and anti-oxidant properties of affected tissues, causing a change in homeostasis that regulates the correct functioning of all cells responsible for the physiological and metabolic balance of various organs. As a consequence, the response to the infection that has caused the change is also likely to be weaker and, in the case of septic shock, ineffective. In this review, we will take into consideration these mechanisms and then focus on a group of vasodilator drugs (prostacyclin and its analogs) which, though have been used for over 20 years mainly to treat obstructive vascular diseases, have such hemodynamic and anti-inflammatory properties which prevent homeostatic changes. It is obvious that prostacyclin does not definitively have anti-infective characteristics; however, in association with anti-infective drugs (antibiotics, etc.), the effectiveness of the latter appears improved, at least in some circumstances. Similarly, the fact that prostacyclin and its analogs have a cytoprotective effect on the liver and reduce the ischemia-reperfusion damage following liver transplant is not a novelty and evidence that they improve hepatic hemodynamics suggests their use in those pathologies characterized by possible reduced perfusion or ascertained ischemia of the liver.

There are many interesting aspects regarding hemorheology and tissue oxygenation in organ transplantation (such as liver, kidney, heart, etc.). The ischemia-reperfusion injury syndrome is a very important problem. Much damage in organs appears to be induced by reperfusion injury syndrome. In fact, not only immunological etiopathogenesis but also biochemically-mediated microcirculation alterations can modulate the organ damage induced by ischemia-reperfusion injury during organ transplantation. During ischemia-reperfusion injury, xanthine oxidase activity, the increase in oxygen free-radicals, and the activation of neuthrophils are all very important. Platelet activating factor (PAT) and LTB4 (promoting neuthrophils adhesiveness), activated by the xanthine oxidase-derived oxidants during reperfusion, activates the final post-ischemia injury. Much research is necessary in order to gain a fuller knowledge of the microcirculation conditions and oxygenation during organ transplantation.

The aim of this study was to establish a pressure ulcer model that visualizes the microcirculation, and to examine the participation of ischemia-reperfusion injury in the pathophysiology of pressure ulcers. An original system composed of a new skin fold chamber and compression device allowed loading quantitative vertical stress to the skin. An intravital microscopic technique enabled direct visualization of the microcirculation in the physiological condition and in response to pressure application. To estimate the effect of ischemia-reperfusion injury, animals were divided into two groups: the compression-release group (n = 8), in which the animals received four cycles of compression-release which consisted of 2 hours of compression followed by 1 hour of pressure release; and the compression alone group (n = 8) in which the animals underwent continuous compression for 8 hours. Functional capillary density was quantified before the compression procedure and on day 1 (35 hours) after the first evaluation. The cyclic compression-release procedure significantly decreased functional capillary density as compared to continuous compression, indicating that in our experimental setting repetition of ischemia-reperfusion cycle more severely damaged the microcirculation than single prolonged ischemic insult. This finding supports the significant contribution of ischemia-reperfusion injury to the pathophysiology of pressure ulcers at the level of dynamic in vivo microcirculation.

Renal damage secondary to ischemia-reperfusion injuries (I-R) is frequent in organ transplantation and adversely affects the graft survival. An important component of this damage is caused by initial adhesion of neutrophils and lymphocytes to endothelial cells. FTY 720, which induces lymphopenia, has previously been shown to display protective effects in models of I-R. The purpose of the present study was to evaluate the combination of FTY 720 and intracellular adhesion molecule and ICAM-1 antisense oligonucleotides (AS-oligos), an agent designed to block the adhesion process.

Sprague-Dawley rats underwent syngenic kidney transplantation after donor kidneys had been preserved in cold solution for 2 hours. The treatment groups included: (1) FTY 720 (1 mg/kg) before reperfusion, (2) AS-oligos (2 mg/kg) during kidney perfusion, and (3) the combination of FTY 720 and AS-oligos. All animals were followed daily after transplantation; some were sacrificed on the second day for histologic analysis.

All treated groups showed a maximal serum creatinine that was significantly less than the control (group 1: 2.76 +/- 1.4, group 2: 2.44 +/- 2.05, group 3: 1.51 +/- 0.42, and control: 4.04 +/- 0.5; P <.01) and returned to the basal value earlier. Also, treated animals showed less histologic stigmata of acute tubular damage. FTY 720 and AS-oligos used in combination showed a mild additive effect.

The use of FTY 720 and/or AS-oligos significantly prevents functional renal damage secondary to I-R, displaying a mild additive effect in this model. Both agents offer the advantage of use during the donor and the graft operations.

Understanding the mechanisms of injury associated with cardiac arrest is essential for defining strategies aimed at improving preservation and function of kidneys harvested in non-heart-beating (NHB) donors.

We standardized a model of NHB donors in rats and studied the kinetics and types (apoptosis vs. necrosis) of renal cell death developing during cold storage. Using quantitative polymerase chain reaction, immunoblotting, and caspase inhibition, we also studied the molecular pathways regulating renal cell death in this model.

The kinetics and extent of cell death developing in cortical tubules during cold storage were found to be increased in non-heart-beating (NHB) kidneys. Apoptosis of cortical tubules predominated in NHB kidneys exposed to 10 hr of cold storage, whereas necrosis increased after longer periods of cold ischemia. Shortly after cardiac arrest, a rapid up-regulation of Bax and Hsp 70 was found at the protein level in NHB kidneys. After 24 hr of cold storage, induction of Bax was maintained, whereas protein levels of Hsp70 returned to levels comparable to heart-beating (HB) controls. Also, mRNA levels of Bax were found to increase during cold storage in NHB kidneys. Cortical cell death was found to be largely caspase-independent but responsive to hydroxyl-radical scavenging with dimethyl sulfoxide (DMSO).

Cardiac arrest promotes activation of death-inducing molecules such as Bax and is associated with increased development of caspase-independent renal cell death during cold storage. Developing strategies, such as free radical scavenging, aimed at inhibiting cell death during cold storage, could prove useful for improving preservation of NHB kidneys.

Basic science research has always been the cornerstone of a solid academic career, even for surgeons. In the past, many cardiothoracic and cardiovascular surgeons have used the large animal laboratory to design surgical operations, refine extracorporeal circulation, improve myocardial protection or simply validate clinical concepts. Today, funding for large animal research has almost disappeared. The basic science areas of 'cellular, molecular, genomics or gene therapy' must be involved to be considered for national or even local funding. This endeavor requires a new generation of surgical scientists and perhaps even more importantly, a new environment for the performance of such research. Academic surgery does not exist without active and long-standing commitment to research. Clinical research focusing on patient outcome remains an important task of the academic surgeon but this paper will focus on the relationship between surgeons and basic scientists and shall concentrate primarily on translational research and its challenge now and in the future. The collaboration between basic scientist and clinician is more essential than ever, because the society still optimally rewards science that has potential clinical applicability [1]. Even within surgical departments, active support and very close contact with PhDs can be essential for the clinical faculty members to be productive, using cellular and molecular techniques. In cardiovascular medicine and biology, there is a great potential to prevent or treat diseases with these techniques. The potential to modify ischemia-reperfusion, inflammation, angiogenesis, restenosis, organ tolerance or cardiomyocyte transplantation to remodel ventricles will be accomplished by a better understanding of cardiovascular biology. Surgeons must plan for a speciality that may look quite different in the next future.