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Eskaf J, Cleveland WJ, Riess ML. No Direct Postconditioning Effect of Poloxamer 188 on Mitochondrial Function after Ischemia Reperfusion Injury in Rat Isolated Hearts. Int J Mol Sci 2021; 22:4879. [PMID: 34063028 PMCID: PMC8124240 DOI: 10.3390/ijms22094879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 05/02/2021] [Accepted: 05/03/2021] [Indexed: 11/17/2022] Open
Abstract
Myocardial infarction is a leading cause for morbidity and mortality worldwide. The only viable treatment for the ischemic insult is timely reperfusion, which further exacerbates myocardial injury. Maintaining mitochondrial function is crucial in preserving cardiomyocyte function in ischemia reperfusion (IR) injury. Poloxamer (P) 188 has been shown to improve cardiac IR injury by improving cellular and mitochondrial function. The aim of this study was to show if P188 postconditioning has direct protective effects on mitochondrial function in the heart. Langendorff prepared rat hearts were subjected to IR injury ex-vivo and reperfused for 10 min with 1 mM P188 vs. vehicle. Cardiac mitochondria were isolated with 1 mM P188 vs. 1 mM polyethylene glycol (PEG) vs. vehicle by differential centrifugation. Mitochondrial function was assessed by adenosine triphosphate synthesis, oxygen consumption, and calcium retention capacity. Mitochondrial function decreased significantly after ischemia and showed mild improvement with reperfusion. P188 did not improve mitochondrial function in the ex-vivo heart, and neither further P188 nor PEG induced direct mitochondrial protection after IR injury in this model.
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Affiliation(s)
- Josephine Eskaf
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (J.E.); (W.J.C.)
- Department of Anesthesiology, University Medicine Greifswald, 17475 Greifswald, Germany
| | - William J. Cleveland
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (J.E.); (W.J.C.)
| | - Matthias L. Riess
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; (J.E.); (W.J.C.)
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232, USA
- Anesthesiology, TVHS VA Medical Center, Nashville, TN 37212, USA
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Sanderson L, da Silva M, Sekhar GN, Brown RC, Burrell-Saward H, Fidanboylu M, Liu B, Dailey LA, Dreiss CA, Lorenz C, Christie M, Persaud SJ, Yardley V, Croft SL, Valero M, Thomas SA. Drug reformulation for a neglected disease. The NANOHAT project to develop a safer more effective sleeping sickness drug. PLoS Negl Trop Dis 2021; 15:e0009276. [PMID: 33857146 PMCID: PMC8078842 DOI: 10.1371/journal.pntd.0009276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/27/2021] [Accepted: 02/26/2021] [Indexed: 01/16/2023] Open
Abstract
Background Human African trypanosomiasis (HAT or sleeping sickness) is caused by the
parasite Trypanosoma brucei sspp. The disease has two
stages, a haemolymphatic stage after the bite of an infected tsetse fly,
followed by a central nervous system stage where the parasite penetrates the
brain, causing death if untreated. Treatment is stage-specific, due to the
blood-brain barrier, with less toxic drugs such as pentamidine used to treat
stage 1. The objective of our research programme was to develop an
intravenous formulation of pentamidine which increases CNS exposure by some
10–100 fold, leading to efficacy against a model of stage 2 HAT. This target
candidate profile is in line with drugs for neglected diseases inititative
recommendations. Methodology To do this, we evaluated the physicochemical and structural characteristics
of formulations of pentamidine with Pluronic micelles (triblock-copolymers
of polyethylene-oxide and polypropylene oxide), selected candidates for
efficacy and toxicity evaluation in vitro, quantified
pentamidine CNS delivery of a sub-set of formulations in vitro and
in vivo, and progressed one pentamidine-Pluronic formulation
for further evaluation using an in vivo single dose brain
penetration study. Principal Findings Screening pentamidine against 40 CNS targets did not reveal any major
neurotoxicity concerns, however, pentamidine had a high affinity for the
imidazoline2 receptor. The reduction in insulin secretion in
MIN6 β-cells by pentamidine may be secondary to pentamidine-mediated
activation of β-cell imidazoline receptors and impairment of cell viability.
Pluronic F68 (0.01%w/v)-pentamidine formulation had a similar inhibitory
effect on insulin secretion as pentamidine alone and an additive
trypanocidal effect in vitro. However, all Pluronics tested
(P85, P105 and F68) did not significantly enhance brain exposure of
pentamidine. Significance These results are relevant to further developing block-copolymers as
nanocarriers, improving BBB drug penetration and understanding the side
effects of pentamidine. Sleeping sickness or human African Trypanosomiasis (HAT) is a disease caused by a
parasite, which is transferred to humans by the bite of an infected tsetse fly.
There are two disease stages: the first stage is the blood-based stage of the
disease and the second stage affects the brain. It is fatal if left untreated.
The blood-brain barrier (BBB) makes the brain stage difficult to treat because
it prevents 99% of all drugs from entering the brain from the blood. Those
anti-HAT drugs that do enter the brain are toxic and have serious side effects.
Pentamidine is a less toxic blood stage drug, which our research has shown has a
limited ability to cross the BBB due to its removal by proteins called
transporters. The objective of this study was to use Pluronic to improve
pentamidine delivery to target sites, whilst reducing its side effects. Pluronic
is a polymer, which can assemble into micelles and encapsulate the drug. Thus,
prolonging its circulation time and protecting it. Our study indicated that the
selected Pluronics did not increase the brain delivery of pentamidine. However.
Pluronic-pentamidine formulations were identified that harboured trypanocidal
activity and did not increase safety concerns compared to unformulated
pentamidine.
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Affiliation(s)
- Lisa Sanderson
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Marcelo da Silva
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Gayathri N. Sekhar
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Rachel C. Brown
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Hollie Burrell-Saward
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Mehmet Fidanboylu
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Bo Liu
- King’s College London, Department of Diabetes, School of Life Course
Sciences, Faculty of Life Sciences & Medicine, London, United
Kingdom
| | - Lea Ann Dailey
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Cécile A. Dreiss
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Chris Lorenz
- King’s College London, Theory & Simulation of Condensed Matter Group,
Department of Physics, Strand, London, United Kingdom
| | - Mark Christie
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
| | - Shanta J. Persaud
- King’s College London, Department of Diabetes, School of Life Course
Sciences, Faculty of Life Sciences & Medicine, London, United
Kingdom
| | - Vanessa Yardley
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Simon L. Croft
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and
Tropical Medicine, London, United Kingdom
| | - Margarita Valero
- Physical Chemistry Department, Faculty of Pharmacy, University of
Salamanca, Salamanca, Spain
| | - Sarah A. Thomas
- King’s College London, Institute of Pharmaceutical Science,
Franklin-Wilkins Building, Stamford Street, London, United
Kingdom
- * E-mail:
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Paapstel K, Kals J, Eha J, Tootsi K, Ottas A, Piir A, Jakobson M, Lieberg J, Zilmer M. Inverse relations of serum phosphatidylcholines and lysophosphatidylcholines with vascular damage and heart rate in patients with atherosclerosis. Nutr Metab Cardiovasc Dis 2018; 28:44-52. [PMID: 28986077 DOI: 10.1016/j.numecd.2017.07.011] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 07/20/2017] [Accepted: 07/24/2017] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND AIMS The rapidly growing discipline of lipidomics allows the study of a wide spectrum of lipid species in body fluids and provides new insights into the pathogenesis of cardiovascular disease. We investigated serum phosphatidylcholine (PC) and lysophosphatidylcholine (lysoPC) species in relation to arterial stiffness, hemodynamics, and endothelial dysfunction in symptomatic patients with atherosclerosis and in healthy controls. METHODS AND RESULTS Thirty-two patients with peripheral arterial disease (age 61.7 ± 9.0 years), 52 patients with coronary artery disease (age 63.2 ± 9.2 years), and 40 apparently healthy controls (age 60.3 ± 7.1 years) were studied. Serum levels of 90 glycerophospholipids were determined with the AbsoluteIDQ™ p180 kit (BIOCRATES Life Sciences AG, Innsbruck, Austria). The technique of applanation tonometry was used for non-invasive pulse wave analysis and carotid-femoral pulse wave velocity (cf-PWV) assessment. Decreased serum levels of several individual PC and lysoPC species (e.g., PC aa C28:1, PC aa C30:0, PC aa C32:2, PC ae C30:0 and PC ae C34:2, lysoPC a C18:2) were observed for the patient groups in comparison to the healthy subjects. In addition, a considerable number of PCs and lysoPCs were inversely related to either cf-PWV, heart rate, asymmetric dimethylarginine (ADMA) or ADMA/arginine for patients with symptomatic atherosclerosis but not for the controls. CONCLUSION We found altered relationships between PC and lysoPC profiles, inflammation, and arterial function in atherosclerotic patients, compared to healthy subjects.
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Affiliation(s)
- K Paapstel
- Institute of Biomedicine and Translational Medicine, Department of Biochemistry, Centre of Excellence for Genomics and Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia; Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia.
| | - J Kals
- Institute of Biomedicine and Translational Medicine, Department of Biochemistry, Centre of Excellence for Genomics and Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia; Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia; Department of Surgery, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
| | - J Eha
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia; Department of Cardiology, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
| | - K Tootsi
- Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
| | - A Ottas
- Institute of Biomedicine and Translational Medicine, Department of Biochemistry, Centre of Excellence for Genomics and Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
| | - A Piir
- Institute of Biomedicine and Translational Medicine, Department of Biochemistry, Centre of Excellence for Genomics and Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia
| | - M Jakobson
- Department of Radiology, Tartu University Hospital, Tartu 51014, Estonia
| | - J Lieberg
- Department of Surgery, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
| | - M Zilmer
- Institute of Biomedicine and Translational Medicine, Department of Biochemistry, Centre of Excellence for Genomics and Translational Medicine, University of Tartu, 19 Ravila Street, Tartu 50411, Estonia; Endothelial Centre, University of Tartu, 8 Puusepa Street, Tartu 51014, Estonia
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Watanabe M, Okada T. Langendorff Perfusion Method as an Ex Vivo Model to Evaluate Heart Function in Rats. Methods Mol Biol 2018; 1816:107-116. [PMID: 29987814 DOI: 10.1007/978-1-4939-8597-5_8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The Langendorff Perfused Heart Model is an experimental procedure developed at the end of the nineteenth century by Oskar Langendorff. In this procedure, an excised heart has a cannula inserted into its aorta so that the heart can be retrogradely perfused via the coronary artery. The procedure has been improved in recent times, and these improvements are used to evaluate the direct effect of medication on the heart as well as the effect of ischemia-reperfusion injury on heart function. In this chapter, we describe protocols for evaluating heart function in Langendorff perfused rat heart.
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Affiliation(s)
- Makino Watanabe
- Department of Physiology, Juntendo University Faculty of Medicine, Tokyo, Japan.
| | - Takao Okada
- Department of Physiology, Juntendo University Faculty of Medicine, Tokyo, Japan
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Poellmann MJ, Lee RC. Repair and Regeneration of the Wounded Cell Membrane. REGENERATIVE ENGINEERING AND TRANSLATIONAL MEDICINE 2017. [DOI: 10.1007/s40883-017-0031-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Akerele OA, Cheema SK. Fatty acyl composition of lysophosphatidylcholine is important in atherosclerosis. Med Hypotheses 2015; 85:754-60. [PMID: 26604024 DOI: 10.1016/j.mehy.2015.10.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/24/2015] [Accepted: 10/14/2015] [Indexed: 12/11/2022]
Abstract
Atherosclerosis is a major cause of death for mankind. Although the pathophysiology of atherosclerosis is a complex and multifactorial process, growing body of evidence has identified phospholipids-mediated signaling as an important factor in the induction and progression of atherosclerosis. Lysophosphatidylcholine (LPC) is a major phospholipid in oxidized low-density lipoprotein, and is generally considered to be atherogenic. However, some studies have shown anti-atherogenic properties of LPC. The controversial findings surrounding the pro- or anti-atherogenic properties of LPC appear to be due to the chain length and the degree of saturation of the fatty acyl moiety of LPC. Studies have suggested that the presence of omega (n)-polyunsaturated fatty acids (PUFA) at the sn-1 position of LPC modulates the inflammatory response thereby making LPC anti-atherogenic. We have recently shown that feeding a diet high in n-3 PUFA resulted in the enrichment of LPC in both plasma and liver of C57BL/6 mice with n-3 PUFA. Others have also shown that supplementation with fish oil leads to preferential incorporation of n-3 PUFA into LPC. We also found that plasma obtained from mice fed a diet high in n-3 PUFA showed higher cholesterol efflux capacity compared to animals fed a low n-3 PUFA diet, despite no changes in high-density lipoprotein concentrations. We are therefore hypothesizing that n-3 PUFA enriched LPC has anti-atherogenic properties by promoting cholesterol efflux from macrophages and by reducing inflammation. Our anticipated long term objective is to establish that the fatty acyl moiety of LPC can be used as a potential biomarker for the risk of developing atherosclerosis. Validating this hypothesis would have a substantial impact on the public health with respect to early diagnosis of cardiovascular risks, and designing dietary based therapeutic strategies for the prevention and management of atherosclerosis and other heart related diseases.
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Lipid metabolites and their differential pro-arrhythmic profiles: of importance in the development of a new anti-arrhythmic pharmacology. Mol Cell Biochem 2014; 393:191-7. [DOI: 10.1007/s11010-014-2060-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 04/11/2014] [Indexed: 01/12/2023]
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8
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Jin C, Wu J, Watanabe M, Okada T, Iesaki T. Mitochondrial K+ channels are involved in ischemic postconditioning in rat hearts. J Physiol Sci 2012; 62:325-32. [PMID: 22528048 PMCID: PMC10717354 DOI: 10.1007/s12576-012-0206-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 03/31/2012] [Indexed: 12/20/2022]
Abstract
The mitochondrial calcium-activated potassium channel (mitoK(Ca)) and the mitochondrial ATP-sensitive potassium channel (mitoK(ATP)) are both involved in cardiac preconditioning. Here, we examined whether these two channels are also involved in ischemic or pharmacological postconditioning. Using Langendorff perfusion, rat hearts were made hypoxic for 45 min and then reoxygenated for 30 min. Ischemic postconditioning (IPT) was achieved through application of 3 cycles of 10 s of reperfusion and 10 s of ischemia before reoxygenation, with and without paxilline (Pax; a mitoK(Ca) blocker) or 5-hydroxydecanoate (5-HD; a mitoK(ATP) blocker). Pharmacological postconditioning was carried out for 5 min at the onset of reoxygenation using NS1619 (a mitoK(Ca) opener) or diazoxide (Dia; a mitoK(ATP) opener). Pax and 5-HD abolished IPT-induced cardioprotection from reoxygenation injury, whereas administration of NS1619 or Dia significantly improved cardiac contractile activity and reduced aspartate aminotransferase (an index of myocyte injury) release following reoxygenation. In addition, isolated rat myocytes were loaded with tetramethylrhodamine methyl ester (TMRE; fluorescent mitochondrial membrane potential indicator) and 2',7'-dichlorofluorescein [DCFH; fluorescent reactive oxygen species (ROS) indicator] or Fluo-4-acetoxymethyl ester (Fluo-4-AM; fluorescent calcium indicator). When TMRE-loaded myocytes were laser illuminated, the DCFH and Fluo-4 fluorescence increased, and TMRE fluorescence decreased. These effects were significantly inhibited by NS1619 and Dia. We therefore conclude that IPT may protect the heart through activation of mitoK(ATP) and mitoK(Ca) channels, and that opening of these channels at the onset of reoxygenation protects the heart from reoxygenation injury, most likely by reducing excess generation of ROS and the resultant Ca(2+) overload.
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Affiliation(s)
- Chunhong Jin
- Department of Physiology, Juntendo University Faculty of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
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Hur MJ, Kim H, Lee DK, Lim SH. The cardioprotective effect of microemulsion propofol against ischemia and reperfusion injury in isolated rat heart. Korean J Anesthesiol 2012; 62:358-64. [PMID: 22558503 PMCID: PMC3337383 DOI: 10.4097/kjae.2012.62.4.358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Revised: 01/18/2012] [Accepted: 01/19/2012] [Indexed: 11/30/2022] Open
Abstract
Background Lipid-emulsion propofol (LP) has cardioprotective effects against ischemia-reperfusion injury, but it has lipid-related side effects. Microemulsion propofol (MP) is a lipid-free propofol emulsified with 10% purified poloxamer 188 (PP188). PP188 is a nonionic surfactant and has cardioprotective effects. However, some reports have suggested that reduced cardioprotective effects were observed when the cardioprotective agents were used in combination even though each cardioprotective agent has cardioprotective effects. The aims of this study were to examine and compare the cardioprotective effects of MP and LP. Methods 50 isolated rat hearts were perfused with modified Kreb's solution. They were divided into 4 groups and underwent 30 minutes of ischemia and 60 minutes of reperfusion. Control group: ischemia-reperfusion was performed without treatment. LP, MP and PP groups: LP, MP and PP188 were infused during the pre-ischemic and reperfusion period, respectively. Hemodynamic parameters and coronary effluent flow rate (CEFR) were measured. Infarct size was determined using triphenyl-tetrazolium staining. Results In the MP group, systolic pressure was maintained near baseline, the systolic pressure was higher than that in the other groups and HR was lower than that in the other groups during reperfusion. Diastolic pressure was transiently increased in the PP group after treatment and at 5 minutes after reperfusion compared with that in the control group and in the the LP group. There were no differences in dP/dtmax and CEFR between groups. Infarct size in the LP, MP and PP groups was smaller than that in the control group, but there were no significant differences between these three groups. Conclusions MP has cardioprotective effects similar to those of LP. MP can be used for cardiac anesthesia in cases with ischemia-reperfusion injury to avoid the lipid-related side effects of LP.
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Affiliation(s)
- Min Jung Hur
- Department of Anesthesiology and Pain Medicine, Korea University Medical Center, Guro Hospital, Seoul, Korea
| | - Heezoo Kim
- Department of Anesthesiology and Pain Medicine, Korea University Medical Center, Guro Hospital, Seoul, Korea
| | - Dong Kyu Lee
- Department of Anesthesiology and Pain Medicine, Korea University Medical Center, Guro Hospital, Seoul, Korea
| | - Sang Ho Lim
- Department of Anesthesiology and Pain Medicine, Korea University Medical Center, Guro Hospital, Seoul, Korea
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Shanta SR, Kim YJ, Kim YH, Kim KP. Application of MALDI Tissue Imaging of Drugs and Metabolites: A New Frontier for Molecular Histology. Biomol Ther (Seoul) 2011. [DOI: 10.4062/biomolther.2011.19.2.149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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12
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Koizumi S, Yamamoto S, Hayasaka T, Konishi Y, Yamaguchi-Okada M, Goto-Inoue N, Sugiura Y, Setou M, Namba H. Imaging mass spectrometry revealed the production of lyso-phosphatidylcholine in the injured ischemic rat brain. Neuroscience 2010; 168:219-25. [PMID: 20362643 DOI: 10.1016/j.neuroscience.2010.03.056] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 03/19/2010] [Accepted: 03/23/2010] [Indexed: 10/19/2022]
Abstract
To develop an effective neuroprotective strategy against ischemic injury, it is important to identify the key molecules involved in the progression of injury. Direct molecular analysis of tissue using mass spectrometry (MS) is a subject of much interest in the field of metabolomics. Most notably, imaging mass spectrometry (IMS) allows visualization of molecular distributions on the tissue surface. To understand lipid dynamics during ischemic injury, we performed IMS analysis on rat brain tissue sections with focal cerebral ischemia. Sprague-Dawley rats were sacrificed at 24 h after middle cerebral artery occlusion, and brain sections were prepared. IMS analyses were conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) in positive ion mode. To determine the molecular structures, the detected ions were subjected to tandem MS. The intensity counts of the ion signals of m/z 798.5 and m/z 760.5 that are revealed to be a phosphatidylcholine, PC (16:0/18:1) are reduced in the area of focal cerebral ischemia as compared to the normal cerebral area. In contrast, the signal of m/z 496.3, identified as a lyso-phosphatidylcholine, LPC (16:0), was clearly increased in the area of focal cerebral ischemia. In IMS analyses, changes of PC (16:0/18:1) and LPC (16:0) are observed beyond the border of the injured area. Together with previous reports--that PCs are hydrolyzed by phospholipase A(2) (PLA(2)) and produce LPCs,--our present results suggest that LPC (16:0) is generated during the injury process after cerebral ischemia, presumably via PLA(2) activation, and that PC (16:0/18:1) is one of its precursor molecules.
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Affiliation(s)
- S Koizumi
- Department of Neurosurgery, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
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Tappia PS, Asemu G, Rodriguez-Leyva D. Phospholipase C as a potential target for cardioprotection during oxidative stressThis review is one of a selection of papers published in a Special Issue on Oxidative Stress in Health and Disease. Can J Physiol Pharmacol 2010; 88:249-63. [DOI: 10.1139/y10-019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cardiac dysfunction due to ischemia–reperfusion (I/R) is associated with marked changes in membrane function and subsequent Ca2+-handling abnormalities in cardiomyocytes. The membrane abnormalities in hearts subjected to I/R arise primarily from oxidative stress as a consequence of increased formation of reactive oxygen species and other oxidants, as well as reduced antioxidant defenses. Little is known, however, about the nature and mechanisms of the sarcolemmal membrane changes with respect to phospholipase C (PLC)-related signaling events. In addition, the mechanisms involved in protection of the postischemic myocardium and in ischemic preconditioning with respect to PLC function need to be established. Accordingly, this article reviews the historical and current information on PLC-mediated signal transduction mechanisms in I/R, as well as outlining future directions that should be addressed. Such information will extend our knowledge of ischemic heart disease and help improve its therapy.
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Affiliation(s)
- Paramjit S. Tappia
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Girma Asemu
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Delfin Rodriguez-Leyva
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Department of Human Nutritional Sciences, Faculty of Human Ecology, University of Manitoba, Winnipeg, Manitoba, Canada
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Mina EW, Lasagna-Reeves C, Glabe CG, Kayed R. Poloxamer 188 copolymer membrane sealant rescues toxicity of amyloid oligomers in vitro. J Mol Biol 2009; 391:577-85. [PMID: 19524592 DOI: 10.1016/j.jmb.2009.06.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 06/08/2009] [Accepted: 06/08/2009] [Indexed: 10/20/2022]
Abstract
Amyloid oligomers and protofibrils increase cell membrane permeability, eventually leading to cell death. Here, we demonstrate that amyloid oligomer toxicity and membrane permeabilization can be reversed using the membrane sealant copolymer poloxamer 188. The data indicate that amyloid oligomer toxicity is caused by defects in the lipid bilayer of the type that are sealed by poloxamer 188. Our results also suggest the possibility of using polymer-based membrane sealants to prevent or reverse amyloid oligomer toxicity in vivo. Because the ability to permeabilize membranes is a generic property of amyloid oligomers, this therapeutic approach may be effective for the treatment of many degenerative diseases caused in part by the interaction of misfolded proteins with cell membranes, as in Alzheimer's disease, type II diabetes, and a host of others.
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Affiliation(s)
- Erene W Mina
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA
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Lapchak PA, Araujo DM. Advances in hemorrhagic stroke therapy: conventional and novel approaches. Expert Opin Emerg Drugs 2007; 12:389-406. [PMID: 17874968 DOI: 10.1517/14728214.12.3.389] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Treatments for spontaneous intracerebral, thrombolytic-induced and intraventricular hemorrhages (IVH) are still at the preclinical or early clinical investigational stages. There has been some renewed interest in the use of surgical evacuation surgery or thrombolytics to remove hematomas, but these techniques can be used only for specific types of brain bleeding. The STICH (Surgical Trial in Intracerebral Haemorrhage) clinical trials should provide some insight into the potential for such techniques to counteract hematoma-induced damage and subsequently, morbidity and mortality. More recently, clinical trials (ATACH [Antihypertensive Treatment in Acute Cerebral Hemorrhage] and INTERACT [Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial]) have begun testing whether or not regulating blood pressure affects the well-being of hemorrhage patients, but the findings thus far have not conclusively demonstrated a positive result. More promising trials, such as the early stage CHANT (Cerebral Hemorrhagic And NXY-059 Treatment) and the late stage FAST (Factor VIIa for Acute Hemorrhagic Stroke Treatment), have addressed whether or not manipulating oxidative stress and components of the blood coagulation cascade can achieve an improved prognosis following spontaneous hemorrhages. However, CHANT was halted prematurely because although it showed that the spin trap agent NXY-059 was safe, it also demonstrated that the drug was ineffective in treating acute ischemic stroke. In addition, the recombinant activated factor VII FAST trial recently concluded with only modestly positive results. Despite a beneficial effect on the primary end point of reducing hemorrhage volume, controlling the coagulation cascade with recombinant factor VIIa did not decrease the mortality rate. Consequently, Novo Nordisk has abandoned further development of the drug for the treatment of intracerebral hemorrhaging. Even though progress in hemorrhage therapy that successfully reduces the escalating morbidity and mortality rate associated with brain bleeding is slow, perseverance and applied translational drug development will eventually be productive. The urgent need for such therapy becomes more evident in light of concerns related to uncontrolled high blood pressure in the general population, increased use of blood thinners by the elderly (e.g., warfarin) and thrombolytics by acute ischemic stroke patients, respectively. The future of drug development for hemorrhage may require a multifaceted approach, such as combining drugs with diverse mechanisms of action. Because of the substantial benefit of factor VIIa in reducing hemorrhage volume, it should be considered as a prime drug candidate included in combination therapy as an off-label use if the FAST trial proves that the risk of thromboembolic events is not increased with drug administration. Other promising drugs that may be considered in combination include uncompetitive NMDA receptor antagonists (such as memantine), antioxidants, metalloprotease inhibitors, statins and erythropoietin analogs, all of which have been shown to reduce hemorrhage and behavioral deficits in one or more animal models.
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Affiliation(s)
- Paul A Lapchak
- University of California San Diego, Department of Neuroscience, MTF 316, 9500 Gilman Drive, La Jolla, CA 92093-0624, USA.
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Matthews KL, Aarsvold JN, Mintzer RA, Chen CT, Lee RC. Tc-99m pyrophosphate imaging of poloxamer-treated electroporated skeletal muscle in an in vivo rat model. Burns 2006; 32:755-64. [PMID: 16837135 PMCID: PMC6139253 DOI: 10.1016/j.burns.2006.01.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Accepted: 01/13/2006] [Indexed: 11/17/2022]
Abstract
OBJECTIVE This study investigates whether (99m)Tc pyrophosphate (PYP) imaging provides a quantitative non-invasive assessment of the extent of electroporation injury, and of the effect of poloxamer in vivo on electroporated skeletal muscle. METHODS High-voltage electrical shock was used to produce electroporation injury in an anesthetized rat's hind limb. In each experiment, the injured limb was treated intravenously by either poloxamer-188, dextran, or saline, and subsequently imaged with (99m)Tc PYP. The radiotracer's temporal behavior among the experimental groups was compared using curve fitting of time-activity curves from the dynamic image data. RESULTS The washout kinetics of (99m)Tc PYP changed in proportion to the electric current magnitude that produced electroporation. Also, (99m)Tc PYP washout from electroporated muscle differed between poloxamer-188 treatment and saline treatment. Finally, 10-kDa dextran treatment of electroporated muscle altered (99m)Tc PYP washout less than poloxamer-188 treatment. CONCLUSIONS Behavior of (99m)Tc PYP in electroporated muscle appears to be an indicator of the amount of electroporation injury. Compared to saline, intravenous polaxamer-188 treatment reduced the amount of (99m)Tc PYP uptake. Coupled to results showing poloxamer-188 seals ruptured cellular membranes, lessens the extent of electroporation injury and improves cell viability, (99m)Tc PYP imaging appears to be a useful in vivo monitoring tool for the extent of electroporation injury.
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Affiliation(s)
- Kenneth L Matthews
- Department of Physics and Astronomy, Louisiana State University, 202 Nicholson Hall, Baton Rouge, LA 70803, USA.
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