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Fulltext Poloxamer 188 (P188), A Potential Polymeric Protective Agent for Central Nervous System Disorders: A Systematic Review

Chen WN, Shaikh MF, Bhuvanendran S, Date A, Ansari MT, Radhakrishnan AK, et al.

Curr Neuropharmacol, 2022;20(4):799-808.
PMID: 34077349 DOI: 10.2174/1570159X19666210528155801

Poloxamer 188 (P188) is an FDA-approved biocompatible block copolymer composed of repeating units of Poly(Ethylene Oxide) (PEO) and poly(propylene oxide) (PPO). Due to its amphiphilic nature and high Hydrophile-Lipophile Balance (HLB) value of 29, P188 is used as a stabilizer/emulsifier in many cosmetics and pharmaceutical preparations. While the applications of P188 as an excipient are widely explored, the data on the pharmacological activity of P188 are scarce. Notably, the neuroprotective potential of P188 has gained a lot of interest. Therefore, this systematic review is aimed at summarizing evidence of neuroprotective potential of P188 in CNS disorders. The PRISMA model was used, and five databases (Google Scholar, Scopus, Wiley Online Library, ScienceDirect, and PubMed) were searched with relevant keywords. The search resulted in 11 articles, which met the inclusion criteria. These articles described the protective effects of P188 on traumatic brain injury or mechanical injury in cells, neurotoxicity, Parkinson's disease, Amyotrophic lateral sclerosis (ALS), and ischemia/ reperfusion injury from stroke. All the articles were original research in experimental or pre-clinical stages using animal models or in vitro systems. The reported activities demonstrated the potential of P188 as a neuroprotective agent in improving CNS conditions such as neurodegeneration.

Matched MeSH terms: Reperfusion Injury*
Causes and Consequences of MicroRNA Dysregulation Following Cerebral Ischemia-Reperfusion Injury

Forouzanfar F, Shojapour M, Asgharzade S, Amini E

CNS Neurol Disord Drug Targets, 2019;18(3):212-221.
PMID: 30714533 DOI: 10.2174/1871527318666190204104629

Stroke continues to be a major cause of death and disability worldwide. In this respect, the most important mechanisms underlying stroke pathophysiology are inflammatory pathways, oxidative stress, as well as apoptosis. Accordingly, miRNAs are considered as non-coding endogenous RNA molecules interacting with their target mRNAs to inhibit mRNA translation or reduce its transcription. Studies in this domain have similarly shown that miRNAs are strongly associated with coronary artery disease and correspondingly contributed to the brain ischemia molecular processes. To retrieve articles related to the study subject, i.e. the role of miRNAs involved in inflammatory pathways, oxidative stress, and apoptosis in stroke from the databases of Web of Science, PubMed (NLM), Open Access Journals, LISTA (EBSCO), and Google Scholar; keywords including cerebral ischemia, microRNA (miRNA), inflammatory pathway, oxidative stress, along with apoptosis were used. It was consequently inferred that, miRNAs could be employed as potential biomarkers for diagnosis and prognosis, as well as therapeutic goals of cerebral ischemia.

Matched MeSH terms: Reperfusion Injury/diagnosis; Reperfusion Injury/metabolism*
The study of myocardial ischemia-reperfusion treatment through computational modelling

Wan Ab Naim WN, Mohamed Mokhtarudin MJ, Chan BT, Lim E, Ahmad Bakir A, Nik Mohamed NA

J Theor Biol, 2021 01 21;509:110527.
PMID: 33096094 DOI: 10.1016/j.jtbi.2020.110527

Reperfusion of the blood flow to ischemic myocardium is the standard treatment for patients suffering myocardial infarction. However, the reperfusion itself can also induce myocardial injury, in which the actual mechanism and its risk factors remain unclear. This work aims to study the mechanism of ischemia-reperfusion treatment using a three-dimensional (3D) oxygen diffusion model. An electrical model is then coupled to an oxygen model to identify the possible region of myocardial damage. Our findings show that the value of oxygen exceeds its optimum (>1.0) at the ischemic area during early reperfusion period. This complication was exacerbated in a longer ischemic period. While a longer reperfusion time causes a continuous excessive oxygen supply to the ischemic area throughout the reperfusion time. This work also suggests the use of less than 0.8 of initial oxygen concentration in the reperfusion treatment to prevent undesired upsurge at the early reperfusion period and further myocardial injury. We also found the region at risk for myocardial injury is confined in the ischemic vicinity revealed by its electrical conductivity impairment. Although there is a risk that reperfusion leads to myocardial injury for excessive oxygen accumulation, the reperfusion treatment is helpful in reducing the infarct size.

Matched MeSH terms: Myocardial Reperfusion Injury*
Role of colchicine to reduce NLRP3 marker in STEMI patients undergo primary PCI: A randomised controlled clinical trial

Karim B, Alwi I, Pasaribu MM, Nafrialdi, Yamin M, Harimurti K, et al.

Med J Malaysia, 2024 Mar;79(2):146-150.
PMID: 38553918

INTRODUCTION: ST-segment elevation myocardial infarction (STEMI) is a fatal disease with significant burden worldwide. Despite advanced medical treatment performed, STEMIrelated morbidity and mortality remains high due to ischemia reperfusion injury after primary angioplasty mediated by NLRP3 inflammasome. Adding colchicine expected to reduce inflammation both in vitro and in vivo. We want to evaluate the effect of colchicine administration on the NLRP3 level of STEMI patient who undergo primary cutaneous intervention (PCI).
MATERIALS AND METHODS: Randomised controlled trial was conducted on STEMI patients who undergo PCI in two hospitals in Jakarta, 104 patients enrolled to this study, and 77 patients completed the trial. 37 patients were randomly assigned to receive colchicines (2 mg loading dose; 0.5 mg thereafter every 12 hour for 48 hours) while 40 patients received placebo. NLRP3 level was measured from venous blood at baseline (BL), after procedure (AP), dan 24-hour post procedure (24H).
RESULTS: No NLRP3 difference was observed initially between colchicine arm and placebo arm 38,69 and 39,0138, respectively (p >0.05). Measurement conducted at 24H, patients received colchicine demonstrate reduction in NLRP3 level (37.67), while placebo arm results increase in NLRP3 level (42.89) despite not statistically significant (p >0,05).
CONCLUSION: Colchicine addition to standard treatment of STEMI patients undergo PCI reduce NLRP3 level despite statistically insignificant.

Matched MeSH terms: Reperfusion Injury*
Renal ischemic injury affects renal hemodynamics and excretory functions in Sprague Dawley rats: involvement of renal sympathetic tone

Salman IM, Sattar MA, Abdullah NA, Ameer OZ, Yam MF, Kaur G, et al.

Ren Fail, 2010 Jan;32(1):96-102.
PMID: 20113274 DOI: 10.3109/08860220903389196

The role of renal sympathetic nerves in the pathogenesis of ischemic acute renal failure (ARF) and the immediate changes in the renal excretory functions following renal ischemia were investigated. Two groups of male Sprague Dawley (SD) rats were anesthetized (pentobarbitone sodium, 60 mg kg(-1) i.p.) and subjected to unilateral renal ischemia by clamping the left renal artery for 30 min followed by reperfusion. In group 1, the renal nerves were electrically stimulated and the responses in the renal blood flow (RBF) and renal vascular resistance (RVR) were recorded, while group 2 was used to study the early changes in the renal functions following renal ischemia. In post-ischemic animals, basal RBF and the renal vasoconstrictor reperfusion to renal nerve stimulation (RNS) were significantly lower (all p < 0.05 vs. control). Mean arterial pressure (MAP), basal RVR, urine flow rate (UFR), absolute and fractional excretions of sodium (U(Na)V and FE(Na)), and potassium (U(K)V and FE(K)) were higher in ARF rats (all p < 0.05 vs. control). Post-ischemic animals showed markedly lower glomerular filtration rate (GFR) (p < 0.05 vs. control). No appreciable differences were observed in urinary sodium to potassium ratio (U(Na)/U(K)) during the early reperfusion phase of renal ischemia (p > 0.05 vs. control). The data suggest an immediate involvement of renal sympathetic nerve action in the pathogenesis of ischemic ARF primarily through altered renal hemodynamics. Diuresis, natriuresis, and kaliuresis due to impaired renal tubular functions are typical responses to renal ischemia and of comparable magnitudes.

Matched MeSH terms: Reperfusion Injury/etiology*; Reperfusion Injury/pathology; Reperfusion Injury/physiopathology*
Fulltext Ischaemia-perfusion injury in the liver. The role of hepatic microvasculature

Lim SP

JUMMEC, 1996;1:9-16.

Research into ischaemia and reperfusion injury especially in liver transplantation has been aimed primarily at preventing deterioration of organ function before harvest and at improving organ preservation techniques. Recent studies however, suggest that postischaemic organ function and viability can be improved not only through improved organ protection before ischaemia, but also with therapy aimed at ameliorating the organ reperfusion injury. In order to develop successful therapeutic interventions against ischaemia-reperfusion induced liver injury, it is necessary to consider the primary site of injury as well as to explore the mechanism(s) and possible factors which may contribute to the injury during ischaemia and reperfusion. Studies on hepatic ischaemia-reperfusion injury have focused mainly at hepatocellular level. Until recently, more attention has been drawn t o the important role of hepatic microcirculation on the pathophysiology of the above injury. The argument that hepatic microvasculature is the primary site of ischaemia-reperfusion injury and possible factors which cause this injury are among the issues reviewed in this article. KEYWORDS: ischaemia, reperfusion, liver, microvasculature, oxygen radicals

Matched MeSH terms: Reperfusion Injury
The study of the function of AQP4 in cerebral ischaemia-reperfusion injury using poroelastic theory

Mokhtarudin MJ, Payne SJ

Int J Numer Method Biomed Eng, 2017 01;33(1).
PMID: 26991256 DOI: 10.1002/cnm.2784

Brain oedema is thought to form and to clear through the use of water-protein channels, aquaporin-4 (AQP4), which are found in the astrocyte endfeet. The model developed here is used to study the function of AQP4 in the formation and elimination of oedema fluid in ischaemia-reperfusion injury. The cerebral space is assumed to be made of four fluid compartments: astrocyte, neuron, ECS and blood microvessels, and a solid matrix for the tissue, and this is modelled using multiple-network poroelastic theory. AQP4 allows the movement of water between astrocyte and the ECS and the microvessels. It is found that the presence of AQP4 may help in reducing vasogenic oedema shown by a decrease in brain tissue extracellular pressure. However, the astrocyte pressure will increase to compensate for this decrease, which may lead to cytotoxic oedema. In addition, the swelling will also depend on the ionic concentrations in the astrocyte and extracellular space, which may change after ischaemic stroke. Understanding the role of AQP4 in oedema may thus help the development of a treatment plan in reducing brain swelling after ischaemia-reperfusion.

Matched MeSH terms: Reperfusion Injury/metabolism*; Reperfusion Injury/pathology
Increased susceptibility of mice obtained from in vitro fertilization to global cerebral ischemia-reperfusion injury: possible role of hydrogen sulphide and its biosynthetic enzymes

Li H, Liu L, Dang M, Zhang W, Liu J

Int J Neurosci, 2020 Jun;130(6):533-540.
PMID: 31516045 DOI: 10.1080/00207454.2019.1667797

Aim of the Study: This study was designed to explore the relative susceptibility of in vitro fertilization (IVF)-conceived mice to global cerebral ischemic injury with the possible role of hydrogen sulphide and enzymes responsible for its production.Materials and Methods: IVF was carried to obtain pups, which were allowed to grow to the age of eight weeks. Thereafter, male mice were subjected to 20 min of global ischemia and 24 h of reperfusion. The mice obtained from other groups including normal mating, superovulation but normal mating and normal mating but embryo implantation were also subjected to global ischemia-reperfusion (I/R) injury.Results: IVF-derived mice exhibited significant more injury in response to I/R injury in comparison to other groups assessed in terms of impairment in locomotor activity, development of motor in coordination, neurological severity score, cerebral infarction and apoptosis markers (caspase-3 activity and Bcl-2 expression). Moreover, there was a relative decrease in the brain levels of hydrogen sulphide (H2S) and its biosynthetic enzymes viz. cystathionine-β-synthase and cystathionine-γ-lyase. Interestingly, the levels of H2S and cystathionine-γ-lyase were significantly low in IVF-derived mice in basal conditions also, i.e. before subjecting to I/R injury and these biochemical alterations were associated with the behavioural deficits in mice, even before subjecting to I/R injury.Conclusion: It is concluded that in vitro fertilization-derived mice are more susceptible to global cerebral I/R injury, which may be possibly due to decreased levels of hydrogen sulphide and its biosynthetic enzymes viz., cystathionine-β-synthase and cystathionine-γ-lyase.

Matched MeSH terms: Reperfusion Injury/etiology; Reperfusion Injury/metabolism*
Current Updates on Potential Role of Flavonoids in Hypoxia/Reoxygenation Cardiac Injury Model

Ali SS, Noordin L, Bakar RA, Zainalabidin S, Jubri Z, Wan Ahmad WAN

Cardiovasc Toxicol, 2021 08;21(8):605-618.
PMID: 34114196 DOI: 10.1007/s12012-021-09666-x

Clinically, timely reperfusion strategies to re-establish oxygenated blood flow in ischemic heart diseases seem to salvage viable myocardium effectively. Despite the remarkable improvement in cardiac function, reperfusion therapy could paradoxically trigger hypoxic cellular injury and dysfunction. Experimental laboratory models have been developed over the years to explain better the pathophysiology of cardiac ischemia-reperfusion injury, including the in vitro hypoxia-reoxygenation cardiac injury model. Furthermore, the use of nutritional myocardial conditioning techniques have been successful. The cardioprotective potential of flavonoids have been greatly linked to its anti-oxidant, anti-apoptotic and anti-inflammatory properties. While several studies have reviewed the cardioprotective properties of flavonoids, there is a scarce evidence of their function in the hypoxia-reoxygenation injury cell culture model. Hence, the aim of this review was to lay out and summarize our current understanding of flavonoids' function in mitigating hypoxia-reoxygenation cardiac injury based on evidence from the last five years. We also discussed the possible mechanisms of flavonoids in modulating the cardioprotective effects as such information would provide invaluable insight on future therapeutic application of flavonoids.

Matched MeSH terms: Myocardial Reperfusion Injury/drug therapy*; Myocardial Reperfusion Injury/metabolism; Myocardial Reperfusion Injury/pathology; Myocardial Reperfusion Injury/physiopathology
Role of the renal sympathetic nervous system in mediating renal ischaemic injury-induced reductions in renal haemodynamic and excretory functions

Salman IM, Ameer OZ, Sattar MA, Abdullah NA, Yam MF, Najim HS, et al.

Pathology, 2010 Apr;42(3):259-66.
PMID: 20350220 DOI: 10.3109/00313021003631304

We investigated the role of renal sympathetic innervation in the deterioration of renal haemodynamic and excretory functions during the early post-ischaemic phase of renal ischaemia/reperfusion injury.

Matched MeSH terms: Reperfusion Injury/complications; Reperfusion Injury/physiopathology*
Non-coding RNAs as therapeutic targets for preventing myocardial ischemia-reperfusion injury

Ong SB, Katwadi K, Kwek XY, Ismail NI, Chinda K, Ong SG, et al.

Expert Opin Ther Targets, 2018 03;22(3):247-261.
PMID: 29417868 DOI: 10.1080/14728222.2018.1439015

INTRODUCTION: New treatments are required to improve clinical outcomes in patients with acute myocardial infarction (AMI), for reduction of myocardial infarct (MI) size and preventing heart failure. Following AMI, acute ischemia/reperfusion injury (IRI) ensues, resulting in cardiomyocyte death and impaired cardiac function. Emerging studies have implicated a fundamental role for non-coding RNAs (microRNAs [miRNA], and more recently long non-coding RNAs [lncRNA]) in the setting of acute myocardial IRI. Areas covered: In this article, we discuss the roles of miRNAs and lncRNAs as potential biomarkers and therapeutic targets for the detection and treatment of AMI, review their roles as mediators and effectors of cardioprotection, particularly in the settings of interventions such as ischemic pre- and post-conditioning (IPC & IPost) as well as remote ischemic conditioning (RIC), and highlight future strategies for targeting ncRNAs to reduce MI size and prevent heart failure following AMI. Expert opinion: Investigating the roles of miRNAs and lncRNAs in the setting of AMI has provided new insights into the pathophysiology underlying acute myocardial IRI, and has identified novel biomarkers and therapeutic targets for detecting and treating AMI. Pharmacological and genetic manipulation of these ncRNAs has the therapeutic potential to improve clinical outcomes in AMI patients.

Matched MeSH terms: Myocardial Reperfusion Injury/genetics; Myocardial Reperfusion Injury/prevention & control*
S-allylcysteine improves ischemia/reperfusion alteration on cardiac function, antioxidant, and mitochondrial permeability

Aziz NF, Ramalingam A, Latip J, Zainalabidin S

Life Sci, 2021 Mar 15;269:119080.
PMID: 33465387 DOI: 10.1016/j.lfs.2021.119080

S-Allylcysteine (SAC) is an extensively studied natural product which has been proven to confer cardioprotection. This potentiates SAC into many clinical relevance possibilities, hence, the use of it ought to be optimally elucidated. To further confirm this, an ischemia/reperfusion model has been used to determine SAC at 10 mM and 50 mM on cardiac function, cardiac marker, and mitochondrial permeability. Using Langendorff setup, 24 adult male Wistar rats' hearts were isolated to be perfused with Kreb-Henseleit buffer throughout the ischemia/reperfusion method. After 20 min of stabilization, global ischemia was induced by turning off the perfusion for 35 min followed by 60 min of reperfusion with either Kreb-Henseleit buffer or SAC with the dose of 10 mM or 50 mM. The cardiac function was assessed and coronary effluent was collected at different timepoints throughout the experiment for lactate dehydrogenase (LDH) measurement. The harvested hearts were then used to measure glutathione while isolated mitochondria for mPTP analysis. SAC-reperfused hearts were shown to prevent the aggravation of cardiac function after I/R induction. It also dose-dependently upregulated glutathione reductase and glutathione level and these were also accompanied by significant reduction of LDH leakage and preserved mitochondrial permeability. Altogether, SAC dose-dependently was able to recover the post-ischemic cardiac function deterioration alongside with improvement of glutathione metabolism and mitochondrial preservation. These findings highly suggest that SAC when sufficiently supplied to the heart would be able to prevent the deleterious complications after the ischemic insult.

Matched MeSH terms: Myocardial Reperfusion Injury/drug therapy*; Myocardial Reperfusion Injury/metabolism; Myocardial Reperfusion Injury/pathology
Effect of antisense oligodeoxynucleotides for ICAM-1 on renal ischaemia-reperfusion injury in the anaesthetised rat

Kiew LV, Munavvar AS, Law CH, Azizan AN, Nazarina AR, Sidik K, et al.

J Physiol, 2004 Jun 15;557(Pt 3):981-9.
PMID: 15047774

An antisense oligodeoxynucleotide (As-ODN) to the 3' untranslated region of the mRNA sequence expressing the intracellular adhesion molecule-1 (ICAM-1) was employed to determine ICAM-1's role in renal ischaemia-reperfusion injury in the rat. Wistar-Kyoto rats receiving i.v. either lipofectin-As-ODN (As-ODN group), lipofectin-reverse ODN (Rv-ODN group) or lipofectin (ischaemia control group) 8 h prior to study were anaesthetized and subjected to 30 min of renal artery occlusion. Renal haemodynamic and excretory parameters were monitored before and after renal ischaemia. On termination of the study renal tissue was subjected to histological and Western blot analysis. Renal blood flow decreased in the 3 h post-ischaemia period in the ischaemia control and Rv-ODN groups, but was maintained in the As-ODN group. Glomerular filtration rate was depressed initially but gradually increased to 10% above basal levels in the ischaemia control and Rv-ODN groups, but was below basal levels (20%) in the As-ODN group. There was a three- to fourfold increase in sodium and water excretion following ischaemia in the ischaemia control and reverse-ODN groups but not in the As-ODN treated group. The As-ODN ameliorated the histological evidence of ischaemic damage and reduced ICAM-1 protein levels to a greater extent in the medulla than cortex. These observations suggested that in the post-ischaemic period afferent and efferent arteriolar tone was increased with a loss of reabsorptive capacity which was in part due to ICAM-1. The possibility arises that the action of ICAM-1 at vascular and tubular sites in the deeper regions of the kidney contributes to the ischaemia-reperfusion injury.

Matched MeSH terms: Reperfusion Injury/drug therapy*; Reperfusion Injury/pathology; Reperfusion Injury/physiopathology
Fulltext Hydrogen Sulphide Treatment Prevents Renal Ischemia-Reperfusion Injury by Inhibiting the Expression of ICAM-1 and NF-kB Concentration in Normotensive and Hypertensive Rats

Hashmi SF, Rathore HA, Sattar MA, Johns EJ, Gan CY, Chia TY, et al.

Biomolecules, 2021 Oct 19;11(10).
PMID: 34680182 DOI: 10.3390/biom11101549

Our main objective was to investigate the effect of chronic administration of hydrogen sulphide donor (sodium hydrosulphide) on the expression of intercellular adhesion molecule-1 (ICAM-1) and concentration of nuclear factor-kappa B (NF-kB) in a renal ischemia-reperfusion injury (IRI) model of WKY and L-nitro-arginine-methyl-ester (L-NAME)-induced hypertensive rats. Sodium hydrosulphide (NaHS) was administered intraperitoneally (i.p.) for 35 days while cystathionine gamma lyase (CSE) inhibitor dL-propargylglycine (PAG) was administered at a single dose of 50 mg/kg. Animals were anesthetised using sodium pentobarbitone (60 mg/kg) and then prepared to induce renal ischemia by clamping the left renal artery for 30 min followed by 3 h of reperfusion. Pre-treatment with NaHS improved the renal functional parameters in both WKY and L-NAME-induced hypertensive rats along with reduction of blood pressure in hypertensive groups. Oxidative stress markers like malondialdehyde (MDA), total superoxide dismutase (T-SOD) and glutathione (GSH) were also improved by NaHS treatment following renal IRI. Levels of ICAM-1 and NF-kB concentration were reduced by chronic treatment with NaHS and increased by PAG administration after renal IRI in plasma and kidney. Treatment with NaHS improved tubular morphology and glomerulus hypertrophy. Pre-treatment with NaHS reduced the degree of renal IRI by potentiating its antioxidant and anti-inflammatory mechanism, as evidenced by decreased NF-kB concentration and downregulation of ICAM-1 expression.

Matched MeSH terms: Reperfusion Injury/drug therapy*; Reperfusion Injury/genetics; Reperfusion Injury/pathology
Effect of kidney ischemia/reperfusion injury on proliferation, apoptosis, and cellular senescence in acute kidney injury in mice

Sari FT, Sari FT, Sari FT, Arfian N, Sari DCR

Med J Malaysia, 2020 05;75(Suppl 1):20-23.
PMID: 32471965

INTRODUCTION: Kidney ischemia/reperfusion injury (IRI) is the leading cause of acute kidney injury (AKI). Kidney IRI demonstrated apoptosis of epithelial cells in acute phase followed by proliferation of interstitial cells in chronic episode, and cellular senescence may contribute to development of AKI, however, its occurrence within acute or chronic episodes is still not completely understood.
METHODS: Kidney IRI was performed with bilateral pediculus clamping in Swiss Background mice (3 months, 30-40g). Mice were euthanised on day one (I/R1, n=6), day eight (I/R8, n=6), and day twelve (I/R12, n=6) to exam acute and chronic episodes. Sham operation procedure was performed in the control. Tubular injury was assessed based on periodic acid- Schift (PAS) staining. Reverse transcriptase PCR (RT-PCR) was done to quantify mRNA expression of Bax, Bcl-2, and p16. Immunohistostaining (IHC) was performed to examine localisation of apoptosis (p53) and proliferation (Bcl-2).
RESULTS: RT-PCR analysis showed upregulation of mRNA expression of Bcl-2, Bax, and p16 (p<0.05). The data showed that ischemia/reperfusion induces upregulation of Bax (p=0.20), Bcl-2 (p=0.45), p16 (p=0.18). Apoptosis and proliferation occurred in the epithelial cells in acute episodes, but occurred in interstitial areas in chronic episodes.
CONCLUSIONS: Ischemia/reperfusion injury induces upregulation proliferation, apoptosis, and cellular senescence in acute kidney injury. Apoptosis reached its peak on day 1, proliferation on day 8, and cellular senescence on day 12.

Matched MeSH terms: Reperfusion Injury/complications*
Fulltext DJ-1 protects against cell death following acute cardiac ischemia-reperfusion injury

Dongworth RK, Mukherjee UA, Hall AR, Astin R, Ong SB, Yao Z, et al.

Cell Death Dis, 2014 Feb 27;5:e1082.
PMID: 24577080 DOI: 10.1038/cddis.2014.41

Novel therapeutic targets are required to protect the heart against cell death from acute ischemia-reperfusion injury (IRI). Mutations in the DJ-1 (PARK7) gene in dopaminergic neurons induce mitochondrial dysfunction and a genetic form of Parkinson's disease. Genetic ablation of DJ-1 renders the brain more susceptible to cell death following ischemia-reperfusion in a model of stroke. Although DJ-1 is present in the heart, its role there is currently unclear. We sought to investigate whether mitochondrial DJ-1 may protect the heart against cell death from acute IRI by preventing mitochondrial dysfunction. Overexpression of DJ-1 in HL-1 cardiac cells conferred the following beneficial effects: reduced cell death following simulated IRI (30.4±4.7% with DJ-1 versus 52.9±4.7% in control; n=5, P<0.05); delayed mitochondrial permeability transition pore (MPTP) opening (a critical mediator of cell death) (260±33 s with DJ-1 versus 121±12 s in control; n=6, P<0.05); and induction of mitochondrial elongation (81.3±2.5% with DJ-1 versus 62.0±2.8% in control; n=6 cells, P<0.05). These beneficial effects of DJ-1 were absent in cells expressing the non-functional DJ-1(L166P) and DJ-1(Cys106A) mutants. Adult mice devoid of DJ-1 (KO) were found to be more susceptible to cell death from in vivo IRI with larger myocardial infarct sizes (50.9±3.5% DJ-1 KO versus 41.1±2.5% in DJ-1 WT; n≥7, P<0.05) and resistant to cardioprotection by ischemic preconditioning. DJ-1 KO hearts showed increased mitochondrial fragmentation on electron microscopy, although there were no differences in calcium-induced MPTP opening, mitochondrial respiratory function or myocardial ATP levels. We demonstrate that loss of DJ-1 protects the heart from acute IRI cell death by preventing mitochondrial dysfunction. We propose that DJ-1 may represent a novel therapeutic target for cardioprotection.

Matched MeSH terms: Myocardial Reperfusion Injury/genetics; Myocardial Reperfusion Injury/metabolism; Myocardial Reperfusion Injury/pathology; Myocardial Reperfusion Injury/prevention & control*
Fulltext Impact of prolonged nicotine administration on myocardial function and susceptibility to ischaemia-reperfusion injury in rats

Ramalingam A, Mohd Fauzi N, Budin SB, Zainalabidin S

Basic Clin Pharmacol Toxicol, 2021 Feb;128(2):322-333.
PMID: 32991780 DOI: 10.1111/bcpt.13500

This study investigated the impact of prolonged nicotine administration on myocardial susceptibility to ischaemia-reperfusion (I/R) injury in a rat model and determined whether nicotine affects mitochondrial reactive oxygen species (ROS) production and permeability transition in rat hearts. Sprague-Dawley rats were administered 0.6 or 1.2 mg/kg nicotine for 28 days, and their hearts were isolated at end-point for assessment of myocardial susceptibility to I/R injury ex vivo. Rat heart mitochondria were also isolated from a subset of rats for analysis of mitochondrial ROS production and permeability transition. Compared to the vehicle controls, rat hearts isolated from nicotine-administered rats exhibited poorer left ventricular function that worsened over the course of I/R. Coronary flow rate was also severely impaired in the nicotine groups at baseline and this worsened after I/R. Nicotine administration significantly increased mitochondrial ROS production and permeability transition relative to the vehicle controls. Interestingly, pre-incubation of isolated mitochondria with ROS scavengers (superoxide dismutase and mitoTEMPO) significantly abolished nicotine-induced increase in mitochondria permeability transition in isolated rat heart mitochondria. Overall, our data showed that prolonged nicotine administration enhances myocardial susceptibility to I/R injury in rats and this is associated with mitochondrial ROS-driven increase in mitochondrial permeability transition.

Matched MeSH terms: Myocardial Reperfusion Injury/chemically induced*; Myocardial Reperfusion Injury/metabolism; Myocardial Reperfusion Injury/pathology; Myocardial Reperfusion Injury/physiopathology
Development of an In Vitro Cardiac Ischemic Model Using Primary Human Cardiomyocytes

Hafez P, Chowdhury SR, Jose S, Law JX, Ruszymah BHI, Mohd Ramzisham AR, et al.

Cardiovasc Eng Technol, 2018 09;9(3):529-538.
PMID: 29948837 DOI: 10.1007/s13239-018-0368-8

Developing experimental models to study ischemic heart disease is necessary for understanding of biological mechanisms to improve the therapeutic approaches for restoring cardiomyocytes function following injury. The aim of this study was to develop an in vitro hypoxic/re-oxygenation model of ischemia using primary human cardiomyocytes (HCM) and define subsequent cytotoxic effects. HCM were cultured in serum and glucose free medium in hypoxic condition with 1% O2 ranging from 30 min to 12 h. The optimal hypoxic exposure time was determined using Hypoxia Inducible Factor 1α (HIF-1α) as the hypoxic marker. Subsequently, the cells were moved to normoxic condition for 3, 6 and 9 h to replicate the re-oxygenation phase. Optimal period of hypoxic/re-oxygenation was determined based on 50% mitochondrial injury via 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide assay and cytotoxicity via lactate dehydrogenase (LDH) assay. It was found that the number of cells expressing HIF-1α increased with hypoxic time and 3 h was sufficient to stimulate the expression of this marker in all the cells. Upon re-oxygenation, mitochondrial activity reduced significantly whereas the cytotoxicity increased significantly with time. Six hours of re-oxygenation was optimal to induce reversible cell injury. The injury became irreversible after 9 h as indicated by > 60% LDH leakage compared to the control group cultured in normal condition. Under optimized hypoxic reoxygenation experimental conditions, mesenchymal stem cells formed nanotube with ischemic HCM and facilitated transfer of mitochondria suggesting the feasibility of using this as a model system to study molecular mechanisms of myocardial injury and rescue.

Matched MeSH terms: Myocardial Reperfusion Injury/metabolism*; Myocardial Reperfusion Injury/pathology
Fulltext White cord syndrome: A devastating complication of spinal decompression surgery

Vinodh VP, Rajapathy SK, Sellamuthu P, Kandasamy R

Surg Neurol Int, 2018;9:136.
PMID: 30090668 DOI: 10.4103/sni.sni_96_18

Background: Reperfusion injury of the spinal cord or "white cord syndrome" refers to the sudden onset of neurological deterioration after spinal decompressive surgery. Associated magnetic resonance (MR) findings only include focal hyperintensity on T2-weighted images without any other pathological changes.
Case Description: A patient with cervical stenosis secondary to metastatic tumor in the intradural and extradural compartments presented with lower limb paraparesis. She underwent an uneventful tumor excision accompanied by posterior cervical decompression and fusion. Postoperatively, she was quadriplegic and required ventilator support. The emergent postoperative MR scan revealed focal hyperintensity on the T2-weighted image consistent with spinal cord edema extending into the lower brain stem.
Conclusion: Very few cases of reperfusion injury of the cervical spinal cord or "white cord syndrome" are described in the literature. Here we present a patient who, following cervical laminectomy and fusion for excision of metastatic tumor, developed quadriplegia. Notably, postoperative MR showed only findings of upper cervical cord and lower brain stem edema consistent with a "white cord syndrome" without other compressive pathology.

Matched MeSH terms: Reperfusion Injury
Fulltext Calpain Inhibition Restores Autophagy and Prevents Mitochondrial Fragmentation in a Human iPSC Model of Diabetic Endotheliopathy

Ong SB, Lee WH, Shao NY, Ismail NI, Katwadi K, Lim MM, et al.

Stem Cell Reports, 2019 03 05;12(3):597-610.
PMID: 30799273 DOI: 10.1016/j.stemcr.2019.01.017

The relationship between diabetes and endothelial dysfunction remains unclear, particularly the association with pathological activation of calpain, an intracellular cysteine protease. Here, we used human induced pluripotent stem cells-derived endothelial cells (iPSC-ECs) to investigate the effects of diabetes on vascular health. Our results indicate that iPSC-ECs exposed to hyperglycemia had impaired autophagy, increased mitochondria fragmentation, and was associated with increased calpain activity. In addition, hyperglycemic iPSC-ECs had increased susceptibility to cell death when subjected to a secondary insult-simulated ischemia-reperfusion injury (sIRI). Importantly, calpain inhibition restored autophagy and reduced mitochondrial fragmentation, concurrent with maintenance of ATP production, normalized reactive oxygen species levels and reduced susceptibility to sIRI. Using a human iPSC model of diabetic endotheliopathy, we demonstrated that restoration of autophagy and prevention of mitochondrial fragmentation via calpain inhibition improves vascular integrity. Our human iPSC-EC model thus represents a valuable platform to explore biological mechanisms and new treatments for diabetes-induced endothelial dysfunction.

Matched MeSH terms: Reperfusion Injury

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