1.Synthesis of (4-18FFluorophenyl)triphenylphosphonium as a Mitochondrial Voltage Sensor for PET.
Dong Yeon KIM ; Kook Hyun YU ; Hee Seung BOM ; Jung Joon MIN
Nuclear Medicine and Molecular Imaging 2007;41(6):561-565
PURPOSE: Lipophilic cations including tetraphenylphosphonium (TPP) salts penetrate the hydrophobic barriers of the plasma and mitochondrial membranes, resulting in accumulation in mitochondria in response to the negative inner transmembrane potentials. The development of radiolabeled phosphonium cations as a noninvasive imaging agent may serve as a new molecular "voltage sensor" probe to investigate the role of mitochondria in the pathophysiology and diagnosis of cancer. MATERIALS AND METHODS: We have synthesized a reference compound (4-fluorophenyl)triphenylphosphonium (TPP) and a labeled compound [18F]TPP via two step nucleophilic substitution of no-carrier-added [18F]fluoride with the precursor, 4-iodophenyltrimethylammonium iodide, in the presence of Kryptofix-2.2.2 and K2CO3. RESULT: The reference compound (4-fluorophenyl)triphenylphosphonium (TPP) was synthesized in 60% yield. The radiolabeled compound [18F]TPP was synthesized in 10~15% yield. The radiochemical purity of the [18F]TPP was 95.57+/-0.51% (n=11). CONCLUSION: [18F]TPP was successfully synthesized that might have a potential to be utilized as a novel myocardial or cancer imaging agent for PET. However, it is required to improve the radiochemical yield to apply [18F]TPP in preclinical or clinical researches.
Cations
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Diagnosis
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Membrane Potential, Mitochondrial
;
Membrane Potentials
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Mitochondria
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Mitochondrial Membranes
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Plasma
;
Salts
2.Mechanism of ablation with nanosecond pulsed electric field.
Chao CEN ; Xin-hua CHEN ; Shu-sen ZHENG
Journal of Zhejiang University. Medical sciences 2015;44(6):678-683
Nanosecond pulsed electric field ablation has been widely applied in clinical cancer treatment, while its molecular mechanism is still unclear. Researchers have revealed that nanosecond pulsed electric field generates nanopores in plasma membrane, leading to a rapid influx of Ca²⁺; it has specific effect on intracellular organelle membranes, resulting in endoplasmic reticulum injuries and mitochondrial membrane potential changes. In addition, it may also change cellular morphology through damage of cytoskeleton. This article reviews the recent research advances on the molecular mechanism of cell membrane and organelle changes induced by nanosecond pulsed electric field ablation.
Ablation Techniques
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Calcium
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Cell Membrane
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physiology
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Cytoskeleton
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Electricity
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Endoplasmic Reticulum
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Humans
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Membrane Potential, Mitochondrial
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Neoplasms
;
therapy
3.Flow cytometric analysis for detecting mitochondrial permeability transition pore opening.
Fang YAN ; Xiao-dong MA ; Xue-mei TIAN
Journal of Southern Medical University 2010;30(9):2097-2099
OBJECTIVETo introduce a new method for detecting mitochondrial permeability transition pore (PTP) opening with flow cytometry using the resveratrol-inducing PTP opening model.
METHODSMitochondria were isolated from rat livers and selectively labeled with nonyl acridine orange. The mitochondrial membrane potential was detected using flow cytometry with TMRE (tetramethylrhodamine, ethyl ester) labeling. PTP opening induced by resveratrol was represented by the changes of mitochondrial side-scattering (SSC) detected by flow cytometry.
RESULTSFlow cytometry was capable of defining the purity of the mitochondria isolated. The fluorescence intensities and SSC of the mitochondria were decreased after resveratrol treatment, indicating that resveratrol could induce PTP opening. Ciclosporin A inhibited resveratrol-induced PTP opening.
CONCLUSIONFlow cytometric analysis allows accurate and convenient detection of mitochondrial membrane potential, mitochondrial swelling and PTP opening.
Animals ; Apoptosis ; Flow Cytometry ; Membrane Potential, Mitochondrial ; genetics ; Mitochondria, Liver ; metabolism ; Mitochondrial Membrane Transport Proteins ; metabolism ; Rats ; Rhodamines
4.Fucodiphlorethol G Purified from Ecklonia cava Suppresses Ultraviolet B Radiation-Induced Oxidative Stress and Cellular Damage.
Ki Cheon KIM ; Mei Jing PIAO ; Jian ZHENG ; Cheng Wen YAO ; Ji Won CHA ; Madduma Hewage Susara Ruwan KUMARA ; Xia HAN ; Hee Kyoung KANG ; Nam Ho LEE ; Jin Won HYUN
Biomolecules & Therapeutics 2014;22(4):301-307
Fucodiphlorethol G (6'-[2,4-dihydroxy-6-(2,4,6-trihydroxyphenoxy)phenoxy]biphenyl-2,2',4,4',6-pentol) is a compound purified from Ecklonia cava, a brown alga that is widely distributed offshore of Jeju Island. This study investigated the protective effects of fucodiphlorethol G against oxidative damage-mediated apoptosis induced by ultraviolet B (UVB) irradiation. Fucodiphlorethol G attenuated the generation of 2, 2-diphenyl-1-picrylhydrazyl radicals and intracellular reactive oxygen species in response to UVB irradiation. Fucodiphlorethol G suppressed the inhibition of human keratinocyte growth by UVB irradiation. Additionally, the wavelength of light absorbed by fucodiphlorethol G was close to the UVB spectrum. Fucodiphlorethol G reduced UVB radiation-induced 8-isoprostane generation and DNA fragmentation in human keratinocytes. Moreover, fucodiphlorethol G reduced UVB radiation-induced loss of mitochondrial membrane potential, generation of apoptotic cells, and active caspase-9 expression. Taken together, fucodiphlorethol G protected human keratinocytes against UVB radiation-induced cell damage and apoptosis by absorbing UVB radiation and scavenging reactive oxygen species.
Apoptosis
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Caspase 9
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DNA Fragmentation
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Humans
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Keratinocytes
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Membrane Potential, Mitochondrial
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Oxidative Stress*
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Reactive Oxygen Species
5.Studies on Signal Transduction Mechanism of Alcohol-induced Neuronal Cell Death and Protective Effect.
Do Yeon LEE ; Sung Su KIM ; Kyung Yong KIM ; Won Bok LEE ; Dae Kyong KIM ; Kyung Hwan KIM ; Hee Youn JUNG ; Sang Hyung LEE
Korean Journal of Physical Anthropology 2004;17(1):31-43
Excessive use of alcohol is a serious problem in our society and induces various, severe alcohol related diseases. The cytotoxicities of ethanol are still largely unknown. We studied the molecular mechanisms of EtOH-induced SK-N-SH neuronal cell death and protective effects of baicalein and gramineus against EtOH-induced cytotoxicities. In our results, the cell death by EtOH showed morphologic features of apoptosis like as membrane blebbing, nuclear condensation and fragmentation. Furthermore, pretreated baicalein attenuated EtOH-induced neuronal cell death effectively. EtOH increased expression levels of p53 and both p53 antisense oligonucleotide and Pifithrin protected the cell death against EtOH. Also, EtOH induced mitochondrial event, collapse of mitochondrial membrane potential ( delta psi m ) and caspase cascade as a downstream of mitochondria. Interestingly, baicalein decreased expression levels of p53 and inhibited collapse of mitochondrial membrane potential. These results suggest that baicalein reduces mitochondrial dysfunction induced by EtOH through down-regulation of p53 expression levels. Also, baicalein attenuated activation of caspase, which was triggered by mitochondrial malfunction. But gramineus didn't have any protective effect. These results imply that baicalein significantly protects EtOH-induced neuronal cell death through regulating p53, mitochondrial dysfunction and caspase activation.
Apoptosis
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Blister
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Cell Death*
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Down-Regulation
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Ethanol
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Membrane Potential, Mitochondrial
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Membranes
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Mitochondria
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Neurons*
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Signal Transduction*
6.Studies on Signal Transduction Mechanism of Alcohol-induced Neuronal Cell Death and Protective Effect.
Do Yeon LEE ; Sung Su KIM ; Kyung Yong KIM ; Won Bok LEE ; Dae Kyong KIM ; Kyung Hwan KIM ; Hee Youn JUNG ; Sang Hyung LEE
Korean Journal of Physical Anthropology 2004;17(1):31-43
Excessive use of alcohol is a serious problem in our society and induces various, severe alcohol related diseases. The cytotoxicities of ethanol are still largely unknown. We studied the molecular mechanisms of EtOH-induced SK-N-SH neuronal cell death and protective effects of baicalein and gramineus against EtOH-induced cytotoxicities. In our results, the cell death by EtOH showed morphologic features of apoptosis like as membrane blebbing, nuclear condensation and fragmentation. Furthermore, pretreated baicalein attenuated EtOH-induced neuronal cell death effectively. EtOH increased expression levels of p53 and both p53 antisense oligonucleotide and Pifithrin protected the cell death against EtOH. Also, EtOH induced mitochondrial event, collapse of mitochondrial membrane potential ( delta psi m ) and caspase cascade as a downstream of mitochondria. Interestingly, baicalein decreased expression levels of p53 and inhibited collapse of mitochondrial membrane potential. These results suggest that baicalein reduces mitochondrial dysfunction induced by EtOH through down-regulation of p53 expression levels. Also, baicalein attenuated activation of caspase, which was triggered by mitochondrial malfunction. But gramineus didn't have any protective effect. These results imply that baicalein significantly protects EtOH-induced neuronal cell death through regulating p53, mitochondrial dysfunction and caspase activation.
Apoptosis
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Blister
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Cell Death*
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Down-Regulation
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Ethanol
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Membrane Potential, Mitochondrial
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Membranes
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Mitochondria
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Neurons*
;
Signal Transduction*
7.Study on the Mitochondrial Dysfunction by p53 Regulation in Ceramide-induced Neuronal Cell Death.
Do Yeon LEE ; Hyun Jung LEE ; Yoo Hun NOH ; Ji Young YUN ; In Sook HAN ; Yoon Hee CHUNG ; Kyung Yong KIM ; Sung Su KIM ; Won Bok LEE
Korean Journal of Physical Anthropology 2006;19(1):49-59
Ceramide induces cell death in a dose- and time-dependent manner in neuroblastoma SK-N-SH cells. To investigate the mechanism of SK-N-SH cell death by C2-ceramide, morphological features and Hoechst 33258 staining were analyzed. In these morphlogic study the cell death by ceramide showed typical apoptotic features, nuclear condensation, fragmentation, and membrane blebbing. Ceramide-induced apoptosis was accompanied by nuclear accumulation of p53. Inhibition of p53 expression with p53 antisense oligonucleotides inhibited apoptosis evoked by ceramide. Also, ceramide induced mitochondrial event, collapse of mitochondrial membrane potential (delta psi m) and interestingly, inhibition of p53 attenuated collapse of mitochondrial membrane potential, suggests that ceramide induces mitochondrial dysfunction through upregulation of p53 expression. These results suggest that ceramide-induced apoptosis is dependent upon increase in cellular p53 levels which play a critical role in the regulation of apoptotic cell death and p53 modulates mitochondrial function such as mitochondrial membrane potential level.
Apoptosis
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Bisbenzimidazole
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Blister
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Cell Death*
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Membrane Potential, Mitochondrial
;
Membranes
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Neuroblastoma
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Neurons*
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Oligonucleotides, Antisense
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Up-Regulation
8.Protective Effect of Ulinastatin against Activation of Tourniquet-Induced Platelet Mitochondria Apoptotic Signaling.
Chun-Yan XIE ; Jin-Fang XIAO ; Zhen-Long ZHAO
Journal of Experimental Hematology 2015;23(4):1087-1091
OBJECTIVETo investigate the protective effect of ulinastatin against the activation of tourniquet-induced platelet mitochondria apoptotic signaling.
METHOD44 patients with unilateral lower limb operation and tourniquet application were randomly divided into normal saline group and ulinastatin group, and were treated with normal saline and ulinastatin respectively. 12 patents with unilateral lower limb operation but without tourniquet application were enrolled in control group. Lipid hydroperoxide (LPO) in serum was detected by LPO assay kit, the content of ATP was examined by fluorescein-luciferase assay kit; the change of mitochondrial membrane potential (Δ ψm) was detected by JC-1 mitochondrial membrane potential kit; the content of cytoplasmic cytochrome C was examined by Cytochrome C ELISA kit; Caspase-3 activity was detected by Caspase-3 fluorometric assay kit.
RESULTSAs compared with control group, the patients in normal saline group exhibited significant platelet mitochondrial dysfunction which characterized by low ATP level and low mitochondrial membrane potential (Δ ψm) (P < 0.05). Tourniquet application resulted in the activation of the mitochondria apoptotic signaling in platelet, displaying increase in the serum LPO level, release of mitochondrial cytochrome C into the cytoplasm, and activation of caspase-3 (P < 0.05). These alterations above-mentioned were obviously improved by ulinastatin treatment (P < 0.05).
CONCLUSIONTourniquet induces platelet mitochondrial dysfunction and mitochondria-dependent apoptotic signaling activation, which can be improved by ulinastatin treatment.
Apoptosis ; Blood Platelets ; Caspase 3 ; Cytochromes c ; Glycoproteins ; Humans ; Membrane Potential, Mitochondrial ; Mitochondria ; Signal Transduction ; Tourniquets
9.NIRF Heptamethine Cyanine Dye Nanocomplexes for Multi Modal Theranosis of Tumors
Reju George THOMAS ; Yong Yeon JEONG
Chonnam Medical Journal 2017;53(2):83-94
Heptamethine cyanine dyes are categorized as a class of near infrared fluorescent (NIRF) dyes which have been discovered to have tumor targeting and accumulation capability. This unique feature of NIRF dye makes it a promising candidate for imaging, targeted therapy and also as a drug delivery vehicle for various types of cancers. The favored uptake of dyes only in cancer cells is facilitated by several factors which include organic anion-transporting polypeptides, high mitochondrial membrane potential and tumor hypoxia in cancer cells. Currently nanotechnology has opened possibilities for multimodal or multifunctional strategies for cancer treatment. Including heptamethine cyanine dyes in nanoparticle based delivery systems have generally improved its theranostic ability by several fold owing to the multiple functionalities and structural features of heptamethine dyes. For this reason, nanocomplexes with NIRF heptamethine cyanine dye probe are preferred over non-targeting dyes such as indo cyanine green (ICG). This review sums up current trends and progress in NIRF heptamethine cyanine dye, including dye properties, multifunctional imaging and therapeutic applications in cancer.
Anoxia
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Coloring Agents
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Drug Delivery Systems
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Fluorescent Dyes
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Membrane Potential, Mitochondrial
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Nanoparticles
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Nanotechnology
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Peptides
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Theranostic Nanomedicine
10.Effect of Ginkgo biloba extract (EGb50) on mitochondrial function in SH-SY5Y cells after hypoxia/reoxygenation injury.
Rong YUAN ; Ye-Hao ZHANG ; Bing-Li CHENG ; Wei-Li SHI ; Qi-Qi XIN ; Yan LU ; Wei-Hong CONG
China Journal of Chinese Materia Medica 2018;43(22):4486-4490
Ischemic cerebrovascular disease and cerebral ischemia/reperfusion injury threaten the health of human being. We studied the protective effect of Ginkgo biloba extract 50 (EGb50) on the mitochondrial function in SH-SY5Y cells after hypoxia/reoxygenation (H/R) injury and explored its mechanisms, so as to provide new ideas for studies on the treatment for ischemic cerebrovascular disease. We established the H/R injury model in SH-SY5Y cells after administrating EGb50. Subsequently, the mitochondrial membrane potential and the concentration of intracellular Ca²⁺ were measured by flow cytometer. The levels of optic atrophy1 (Opa1) and dynamin-like protein 1 (Drp1) were evaluated by immunofluorescence and western blot. The results showed that the mitochondrial membrane potential was decreased and the level of intracellular Ca²⁺ was increased after H/R injury. Moreover, the expression of mitochondrial fusion protein Opa1 was decreased, while the expression of mitochondrial fission protein Drp1 was increased. However, EGb50 significantly increased the mitochondrial membrane potential and suppressed the level of intracellular Ca²⁺. In addition, EGb50 increased the expression of Opa1 and decreased the expression of Drp1. The results demonstrated that EGb50 has a neuroprotective effect on SH-SY5Y cells after H/R injury, and could improve the energy metabolism and mitochondrial function. The underlying mechanisms may be associated with the regulation of mitochondrial fusion and fission, which provided data support for the treatment of ischemic cerebrovascular disease with EGb50.
Cell Hypoxia
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Humans
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Membrane Potential, Mitochondrial
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Mitochondria
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Plant Extracts
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Reperfusion Injury