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Li L, Wang X, Wang S, Wen L, Zhang H. Altitude effect on Propofol Pharmacokinetics in Rats. Curr Drug Metab 2024; 25:81-90. [PMID: 38468514 DOI: 10.2174/0113892002285571240220131547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 12/26/2023] [Accepted: 02/06/2024] [Indexed: 03/13/2024]
Abstract
BACKGROUND Propofol is an intravenous agent for clinical anesthesia. As the influence of the hypobaric- hypoxic environment (Qinghai-Tibetan region, altitude: 2800-4300 m, PaO2: 15.1-12.4 kPa) on the metabolism of Propofol is complex, the research results on the metabolic characteristics of Propofol in high- -altitude areas remain unclear. This study aimed to investigate the pharmacokinetic characteristics of Propofol in a high-altitude hypoxic environment using animal experiments. METHODS Rats were randomly divided into three groups: high-altitude, medium-altitude, and plain groups. The time of disappearance and recovery of the rat righting reflex was recorded as the time of anesthesia induction and awakening, respectively. The plasma concentration of Propofol was determined by gas chromatography- mass spectrometry. A pharmacokinetic analysis software was used to analyze the blood-drug concentrations and obtain the pharmacokinetic parameters. RESULTS We observed that when Propofol anesthetizes rats, the anesthesia induction time was shortened, and the recovery time was prolonged with increased altitude. Compared with the plain group, the clearance of Propofol decreased, whereas the half-life, area under the concentration-time curve, peak plasma concentration, and average residence time extension increased. CONCLUSION The pharmacokinetic characteristics of Propofol are significantly altered in high-altitude hypoxic environments.
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Affiliation(s)
- Lijun Li
- Department of Anesthesiology, The First People's Hospital of Ziyang City, Ziyang 641300, China
| | - Xuejun Wang
- Department of Anesthesiology, Qinghai Red Cross Hospital, Xining 810000, China
| | - Sheng Wang
- Department of Anesthesiology, Dazhou Central Hospital, Dazhou 635000, China
| | - Li Wen
- Department of Anesthesiology, The Third Military Medical University, Chongqing 400000, China
| | - Haopeng Zhang
- Department of Anesthesiology, Xijing Hospital of Air Force Military Medical University, Xi'an710000, China
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2
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Aranda JF, Pérez-García A, Torrecilla-Parra M, Fernández-de Frutos M, Martín-Martín Y, Mateos-Gómez PA, Pardo-Marqués V, Busto R, Ramírez CM. Role of miR-199a-5p in the post-transcriptional regulation of ABCA1 in response to hypoxia in peritoneal macrophages. Front Cardiovasc Med 2022; 9:994080. [DOI: 10.3389/fcvm.2022.994080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
Hypoxia is a crucial factor contributing to maintenance of atherosclerotic lesions. The ability of ABCA1 to stimulate the efflux of cholesterol from cells in the periphery, particularly foam cells in atherosclerotic plaques, is an important anti-atherosclerotic mechanism. The posttranscriptional regulation by miRNAs represents a key regulatory mechanism of a number of signaling pathways involved in atherosclerosis. Previously, miR-199a-5p has been shown to be implicated in the endocytic and retrograde intracellular transport. Although the regulation of miR-199a-5p and ABCA1 by hypoxia has been already reported independently, the role of miR-199a-5p in macrophages and its possible role in atherogenic processes such us regulation of lipid homeostasis through ABCA1 has not been yet investigated. Here, we demonstrate that both ABCA1 and miR-199a-5p show an inverse regulation by hypoxia and Ac-LDL in primary macrophages. Moreover, we demonstrated that miR-199a-5p regulates ABCA1 mRNA and protein levels by directly binding to its 3’UTR. As a result, manipulation of cellular miR-199a-5p levels alters ABCA1 expression and cholesterol efflux in primary mouse macrophages. Taken together, these results indicate that the correlation between ABCA1-miR-199a-5p could be exploited to control macrophage cholesterol efflux during the onset of atherosclerosis, where cholesterol alterations and hypoxia play a pathogenic role.
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Lopez-Pascual A, Trayhurn P, Martínez JA, González-Muniesa P. Oxygen in Metabolic Dysfunction and Its Therapeutic Relevance. Antioxid Redox Signal 2021; 35:642-687. [PMID: 34036800 DOI: 10.1089/ars.2019.7901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Significance: In recent years, a number of studies have shown altered oxygen partial pressure at a tissue level in metabolic disorders, and some researchers have considered oxygen to be a (macro) nutrient. Oxygen availability may be compromised in obesity and several other metabolism-related pathological conditions, including sleep apnea-hypopnea syndrome, the metabolic syndrome (which is a set of conditions), type 2 diabetes, cardiovascular disease, and cancer. Recent Advances: Strategies designed to reduce adiposity and its accompanying disorders have been mainly centered on nutritional interventions and physical activity programs. However, novel therapies are needed since these approaches have not been sufficient to counteract the worldwide increasing rates of metabolic disorders. In this regard, intermittent hypoxia training and hyperoxia could be potential treatments through oxygen-related adaptations. Moreover, living at a high altitude may have a protective effect against the development of abnormal metabolic conditions. In addition, oxygen delivery systems may be of therapeutic value for supplying the tissue-specific oxygen requirements. Critical Issues: Precise in vivo methods to measure oxygenation are vital to disentangle some of the controversies related to this research area. Further, it is evident that there is a growing need for novel in vitro models to study the potential pathways involved in metabolic dysfunction to find appropriate therapeutic targets. Future Directions: Based on the existing evidence, it is suggested that oxygen availability has a key role in obesity and its related comorbidities. Oxygen should be considered in relation to potential therapeutic strategies in the treatment and prevention of metabolic disorders. Antioxid. Redox Signal. 35, 642-687.
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Affiliation(s)
- Amaya Lopez-Pascual
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,Neuroendocrine Cell Biology, Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Paul Trayhurn
- Obesity Biology Unit, University of Liverpool, Liverpool, United Kingdom.,Clore Laboratory, The University of Buckingham, Buckingham, United Kingdom
| | - J Alfredo Martínez
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.,CIBERobn Physiopathology of Obesity and Nutrition, Centre of Biomedical Research Network, ISCIII, Madrid, Spain.,Precision Nutrition and Cardiometabolic Health, IMDEA Food, Madrid Institute for Advanced Studies, Madrid, Spain
| | - Pedro González-Muniesa
- Department of Nutrition, Food Science and Physiology, School of Pharmacy and Nutrition, Centre for Nutrition Research, University of Navarra, Pamplona, Spain.,IdiSNA, Navarra Institute for Health Research, Pamplona, Spain.,CIBERobn Physiopathology of Obesity and Nutrition, Centre of Biomedical Research Network, ISCIII, Madrid, Spain
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4
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Liang S, Ning R, Zhang J, Liu J, Zhang J, Shen H, Chen R, Duan J, Sun Z. MiR-939-5p suppresses PM 2.5-induced endothelial injury via targeting HIF-1α in HAECs. Nanotoxicology 2021; 15:706-720. [PMID: 33941019 DOI: 10.1080/17435390.2021.1917716] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ambient air pollution is a leading cause of non-communicable disease in the world. PM2.5 has the potential to change the miRNAs profiles, which in turn causes cardiovascular effects. Hypoxia-inducible factor (HIF)-1 plays a critical role in the development of atherosclerosis. Yet, the possible role of miR-939-5p/HIF-1α in PM2.5-induced endothelial injury remains elusive. Therefore, the study aims to investigate the effects of miR-939-5p and HIF-1α on PM2.5-triggered endothelial injury. The results from immunofluorescence, qRT-PCR, LSCM, and western blot assays demonstrated that PM2.5 increased the levels of HIF-1α, inflammation and apoptosis in human aortic endothelial cells (HAECs). Yet, the inflammatory response and mitochondrial-mediated apoptosis pathway were effectively inhibited in HIF-1α knockdown HAECs lines. The expression of miR-939-5p was significantly down-regulated in HAECs after exposed to PM2.5. The luciferase reporter, qRT-PCR and western blot results demonstrated that miR-939-5p could directly targeted HIF-1α. And the miR-939-5p overexpression restricted PM2.5-triggered decreases in cell viability and increases in lactic dehydrogenase (LDH) activity, reactive oxygen species (ROS), mitochondrial membrane potential (MMP) and inflammation. In addition, miR-939-5p overexpression remarkably suppressed PM2.5-triggered BcL-2/Bax ratio reduction and Cytochrome C, Cleaved Caspase-9 and Cleaved Caspase-3 expression increase, revealed that miR-939-5p hampered PM2.5-induced endothelial apoptosis through mitochondrial-mediated apoptosis pathway. Our results demonstrated that PM2.5 increased the expression of HIF-1α followed by a pro-inflammatory and apoptotic response in HAECs. The protective effect of miR-939-5p on PM2.5-triggered endothelial cell injury by negatively regulating HIF-1α. miR-939-5p might present a new therapeutic target for PM2.5 induced endothelial injury.
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Affiliation(s)
- Shuang Liang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Ruihong Ning
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Jingyi Zhang
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Jiangyan Liu
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Jie Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, PR China
| | - Heqing Shen
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, PR China.,Key Laboratory of Urban Environment and Health, Chinese Academy of Sciences, Institute of Urban Environment, Xiamen, PR China
| | - Rui Chen
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Junchao Duan
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
| | - Zhiwei Sun
- Department of Toxicology and Sanitary Chemistry, School of Public Health, Capital Medical University, Beijing, PR China.,Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, PR China
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Gong L, Zhang Y, Liu C, Zhang M, Han S. Application of Radiosensitizers in Cancer Radiotherapy. Int J Nanomedicine 2021; 16:1083-1102. [PMID: 33603370 PMCID: PMC7886779 DOI: 10.2147/ijn.s290438] [Citation(s) in RCA: 166] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Radiotherapy (RT) is a cancer treatment that uses high doses of radiation to kill cancer cells and shrink tumors. Although great success has been achieved on radiotherapy, there is still an intractable challenge to enhance radiation damage to tumor tissue and reduce side effects to healthy tissue. Radiosensitizers are chemicals or pharmaceutical agents that can enhance the killing effect on tumor cells by accelerating DNA damage and producing free radicals indirectly. In most cases, radiosensitizers have less effect on normal tissues. In recent years, several strategies have been exploited to develop radiosensitizers that are highly effective and have low toxicity. In this review, we first summarized the applications of radiosensitizers including small molecules, macromolecules, and nanomaterials, especially those that have been used in clinical trials. Second, the development states of radiosensitizers and the possible mechanisms to improve radiosensitizers sensibility are reviewed. Third, the challenges and prospects for clinical translation of radiosensitizers in oncotherapy are presented.
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Affiliation(s)
- Liuyun Gong
- Department of Oncology, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Yujie Zhang
- School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
- Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Chengcheng Liu
- School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Mingzhen Zhang
- School of Basic Medical Sciences, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
- Key Laboratory of Environment and Genes Related to Diseases, Xi’an Jiaotong University, Ministry of Education, Xi’an, Shaanxi, 710061, People’s Republic of China
| | - Suxia Han
- Department of Oncology, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, 710061, People’s Republic of China
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Ghanbari Movahed Z, Rastegari-Pouyani M, Mohammadi MH, Mansouri K. Cancer cells change their glucose metabolism to overcome increased ROS: One step from cancer cell to cancer stem cell? Biomed Pharmacother 2019; 112:108690. [PMID: 30798124 DOI: 10.1016/j.biopha.2019.108690] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 12/11/2022] Open
Abstract
Cancer cells can adapt to low energy sources in the face of ATP depletion as well as to their high levels of ROS by altering their metabolism and energy production networks which might also have a role in determining cell fate and developing drug resistance. Cancer cells are generally characterized by increased glycolysis. This is while; cancer stem cells (CSCs) exhibit an enhanced pentose phosphate pathway (PPP) metabolism. Based on the current literature, we suggest that cancer cells when encountering ROS, first increase the glycolysis rate and then following the continuation of oxidative stress, the metabolic balance is skewed from glycolysis to PPP. Therefore, we hypothesize in this review that in cancer cells this metabolic deviation during persistent oxidative stress might be a sign of cancer cells' shift towards CSCs, an issue that might be pivotal in more effective targeting of cancer cells and CSCs.
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Affiliation(s)
- Zahra Ghanbari Movahed
- Medical Biology Research Center, Kermanshah University of Medical sciences, Kermanshah, Iran
| | - Mohsen Rastegari-Pouyani
- Student Research Committee, Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Hossein Mohammadi
- HSCT research center, Laboratory Hematology and blood Banking Department, School of Allied Medical Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran
| | - Kamran Mansouri
- Medical Biology Research Center, Kermanshah University of Medical sciences, Kermanshah, Iran; Department of Molecular Medicine, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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7
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Xu G. HIF-1-mediated expression of Foxo1 serves an important role in the proliferation and apoptosis of osteoblasts derived from children's iliac cancellous bone. Mol Med Rep 2018; 17:6621-6631. [PMID: 29512721 DOI: 10.3892/mmr.2018.8675] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 02/08/2018] [Indexed: 11/06/2022] Open
Abstract
Activation of the transcription factor hypoxia inducible factor‑1α (HIF-1α) is considered critical for the stimulation of osteogenic markers including runt‑related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin, which are closely associated with forkhead boxclass O1 (Foxo1) levels in osteoblasts. The present study explored the associations between HIF‑1α and Foxo1 in the regulation of cell viability, proliferation and apoptosis of osteoblasts. Osteoblasts obtained from children's iliac cancellous bone were used in the present study, which were confirmed by immunofluorescence staining for the osteoblast marker osteocalcin. The results revealed that the levels of reactive oxygen species and apoptosis were markedly increased in cells with knockdown of HIF‑1α. By contrast, these were reduced in response to overexpressed HIF‑1α. In addition, HIF‑1α overexpression significantly stimulated cell viability, which was suppressed by silencing HIF‑1α. HIF‑1α overexpression also significantly increased the transcriptional and translational levels of Foxo1. Conversely, silencing HIF‑1α markedly suppressed the expression levels of Foxo1. Furthermore, silencing HIF‑1α reduced the expression of osteogenic markers, including Runx2, ALP and osteocalcin. Runx2 and ALP expression induced by HIF1α were markedly reversed by Foxo1 small interfering (si)RNA, whereas osteocalcin was not significantly affected by Foxo1 siRNA. Therefore, the cooperation of and interactions between HIF‑1α and Foxo1 may be involved in the regulation of osteoblast markers, and serve a pivotal role in the proliferation and apoptosis of osteoblast. The HIF1α‑induced expression of Runx2 and ALP may be completely dependent on the expression levels of Foxo1, and in turn, osteocalcin may be partially dependent on Foxo1 expression.
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Affiliation(s)
- Gang Xu
- Department of Orthopedics, The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310000, P.R. China
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8
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Wang Z, Zhang K, Zhu Y, Wang D, Shao Y, Zhang J. Curcumin inhibits hypoxia-induced proliferation and invasion of MG-63 osteosarcoma cells via downregulating Notch1. Mol Med Rep 2017; 15:1747-1752. [PMID: 28138706 DOI: 10.3892/mmr.2017.6159] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 11/11/2016] [Indexed: 11/05/2022] Open
Abstract
Curcumin is a biologically active ingredient abundantly present in the ground rhizomes of Curcuma longa with a wide range of bioactive properties, including antitumor effects. Hypoxia is a common characteristic of solid tumors, including osteosarcoma. However, whether curcumin has antitumor effects on osteosarcoma under hypoxic conditions, and its underlying molecular mechanisms, remain unclear. The present study demonstrated that the MG‑63 osteosarcoma cell line exhibited increased proliferation and enhanced invasiveness upon exposure to hypoxic conditions. However, these effects were prevented by curcumin treatment. Further investigation revealed that curcumin may inhibit Notch1 upregulation induced by hypoxia. Overexpression of Notch1 via Notch1 cDNA transfection ameliorated curcumin‑inhibited MG‑63 cell growth under hypoxic conditions. Taken together, these data revealed that curcumin may suppress the growth of osteosarcoma cells in hypoxia via inhibiting Notch1 signaling.
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Affiliation(s)
- Zhan Wang
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
| | - Kun Zhang
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
| | - Yangjun Zhu
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
| | - Dengfeng Wang
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
| | - Yuxiong Shao
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
| | - Jun Zhang
- Department of Orthopaedics, Hong Hui Hospital, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710054, P.R. China
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9
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Abstract
The ‘holy grail’ in radiation oncology is to improve the outcome of radiation therapy (RT) with a radiosensitizer—a systemic chemical/biochemical agent that additively or synergistically sensitizes tumor cells to radiation in the absence of significant toxicity. Similar to the oxygen effect, in which DNA bases modified by reactive oxygen species prevent repair of the cellular radiation damage, these compounds in general magnify free radical formation, leading to the permanent “fixation” of the resultant chemical change in the DNA structure. The purpose of this review is to present the origin story of the radiosensitizer, RRx-001, which emerged from the aerospace industry. The activity of RRx-001 as a chemosensitizer in multiple tumor types and disease states including malaria, hemorrhagic shock and sickle cell anemia, are the subject of future reviews.
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Niecknig H, Tug S, Reyes BD, Kirsch M, Fandrey J, Berchner-Pfannschmidt U. Role of reactive oxygen species in the regulation of HIF-1 by prolyl hydroxylase 2 under mild hypoxia. Free Radic Res 2012; 46:705-17. [PMID: 22360728 DOI: 10.3109/10715762.2012.669041] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The function and survival of eukaryotic cells depends on a constant and sufficient oxygen supply. Cells recognize and respond to hypoxia by accumulation of the transcription factor hypoxia-inducible factor 1 (HIF-1), composed of an oxygen-sensitive HIF-1α and a constitutive HIF-1β subunit. Besides physiology, HIF-1 induction is involved in major pathological processes such as cardiovascular disease, inflammation and cancer, which are associated with the formation of reactive oxygen species (ROS). ROS have been reported to affect HIF-1 activity but the role for ROS in regulating HIF-1 has not been definitely settled. In order to shed light on the redox-regulation of HIF-1 by ROS, we studied the impact of exogenous ROS treatment (H(2)O(2)) on HIF-1α and HIF-1 regulatory protein prolyl hydroxylase 2 (PHD2) in the human osteosarcoma cell line U2OS. At early reaction periods, H(2)O(2) induced HIF-1α but at prolonged observation phases the opposite occurred. Herein, modulation of PHD activity appeared to be the key element, because knockdown and inhibition of the PHD2 prevented reduction of HIF-1α. However, H(2)O(2) treatment constantly suppressed HIF-1 transactivation at all time-points. Our data indicate a dual redox regulation of HIF-1α protein amount with a constant suppression of HIF-1 target gene expression by ROS.
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Affiliation(s)
- Helene Niecknig
- Institut für Physiologie, Universität Duisburg-Essen, Germany
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Parathath S, Mick SL, Feig JE, Joaquin V, Grauer L, Habiel DM, Gassmann M, Gardner LB, Fisher EA. Hypoxia is present in murine atherosclerotic plaques and has multiple adverse effects on macrophage lipid metabolism. Circ Res 2011; 109:1141-52. [PMID: 21921268 DOI: 10.1161/circresaha.111.246363] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
RATIONALE Human atherosclerotic plaques contain large numbers of cells deprived of O(2). In murine atherosclerosis, because the plaques are small, it is controversial whether hypoxia can occur. OBJECTIVE To examine if murine plaques contain hypoxic cells, and whether hypoxia regulates changes in cellular lipid metabolism and gene expression in macrophages. METHODS AND RESULTS Aortic plaques from apolipoprotein-E-deficient mice were immunopositive for hypoxia-inducible transcription factor (HIF-1α) and some of its downstream targets. Murine J774 macrophages rendered hypoxic demonstrated significant increases in cellular sterol and triglycerides. The increase in sterol content in hypoxic macrophages correlated with elevated 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase activity and mRNA levels. In addition, when macrophages were incubated with cholesterol complexes, hypoxic cells accumulated 120% more cholesterol, predominately in the free form. Cholesterol-efflux assays showed that hypoxia significantly decreased efflux mediated by ATP-binding cassette subfamily A member 1 (ABCA1), whose sub cellular localization was altered in both J774 and primary macrophages. Furthermore, in vivo expression patterns of selected genes from cells in hypoxic regions of murine plaques were similar to those from J774 and primary macrophages incubated in hypoxia. The hypoxia-induced accumulation of sterol and decreased cholesterol efflux was substantially reversed in vitro by reducing the expression of the hypoxia-inducible transcription factor, HIF-1α. CONCLUSION Hypoxic regions are present in murine plaques. Hypoxic macrophages have increased sterol content due to the induction of sterol synthesis and the suppression of cholesterol efflux, effects that are in part mediated by HIF-1α.
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Affiliation(s)
- Sajesh Parathath
- NYU School of Medicine, Departments of Medicine (Cardiology) and Cell Biology, Marc and Ruti Bell Program in Vascular Biology, New York, NY 10016, USA
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12
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Six degrees of separation: the oxygen effect in the development of radiosensitizers. Transl Oncol 2011; 4:189-98. [PMID: 21804913 DOI: 10.1593/tlo.11166] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 05/06/2011] [Accepted: 05/11/2011] [Indexed: 11/18/2022] Open
Abstract
The popular theory six degrees of separation is used in this review as an analogy to relate all radiosensitization to oxygen. As the prime mover of all radiosensitizers, the pervasive influence of oxygen has consciously or unconsciously influenced the direction of research and development and provided the benchmark against which all other compounds and approaches are measured. It is the aim of this review to develop the six degrees of separation from oxygen analogy as a unifying framework for conceptually organizing the field and for giving context to its varied subspecializations and theories. Under such a framework, it would become possible for one area to consider questions and problems found in other areas of radiosensitization, using a common analogy, that would allow for further development and unification of this multifaceted discipline. In this review, approaches to the development of radiosensitizers and the current state of research in this field are discussed, including promising new agents in various stages of clinical development.
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13
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Shi M, Guo XT, Shu MG, Chen FL, Li LW. Cell-permeable hypoxia-inducible factor-1 (HIF-1) antagonists function as tumor radiosensitizers. Med Hypotheses 2007; 69:33-5. [PMID: 17280792 DOI: 10.1016/j.mehy.2006.10.062] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Accepted: 10/19/2006] [Indexed: 11/15/2022]
Abstract
Hypoxia is a common phenomenon in human solid tumors and has been considered as an important, independent negative prognostic factor for response to treatment and survival of tumor patients. Hypoxia-inducible factor-1 (HIF-1) is the central transcription factor which is activated by hypoxia and modulates the expression of many genes involved in cell metabolism, proliferation, apoptosis, angiogenesis. Recently, it has been reported that HIF-1 contributes to tumor radioresistance by upregulating survivin expression under hypoxic conditions. Moreover, in hypoxic tumor cells, HIF-1 dependent signal transduction pathway is activated and could be further enhanced by radiation, thereby providing survival signals to adjacent vascular endothelial cells by upregulation of VEGF and bFGF and resulting in tumor radioresistance through vascular radioprotection. Recent research revealed that the stability of HIF-1alpha, one of the two subunits of HIF-1, determines the whole HIF-1 activity and the C-terminal transactivation domain of HIF-1alpha could reduce HIF-1 activity when overexpressed in tumor cells by disruption of the assembly of HIF-1 transcription complex. Therefore, we postulate that fusion with protein transduction domains would overcome the inability of C-terminal transactivation domain of HIF-1alpha to cross cellular membrane. Thus the recombinant fusion proteins could serve as cell-permeable HIF-1 antagonists, function as both inhibitors of tumor angiogenesis and tumor radiosensitizers, and would be widely used in clinical settings to improve tumor response to radiotherapy.
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Affiliation(s)
- Mei Shi
- Department of Radiotherapy, Xijing Hospital, The Fourth Military Medical University, No.17 Changle Western Road, Xi'an 710032, China
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