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Choi YK. Detrimental Roles of Hypoxia-Inducible Factor-1α in Severe Hypoxic Brain Diseases. Int J Mol Sci 2024; 25:4465. [PMID: 38674050 PMCID: PMC11050730 DOI: 10.3390/ijms25084465] [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: 03/14/2024] [Revised: 04/12/2024] [Accepted: 04/17/2024] [Indexed: 04/28/2024] Open
Abstract
Hypoxia stabilizes hypoxia-inducible factors (HIFs), facilitating adaptation to hypoxic conditions. Appropriate hypoxia is pivotal for neurovascular regeneration and immune cell mobilization. However, in central nervous system (CNS) injury, prolonged and severe hypoxia harms the brain by triggering neurovascular inflammation, oxidative stress, glial activation, vascular damage, mitochondrial dysfunction, and cell death. Diminished hypoxia in the brain improves cognitive function in individuals with CNS injuries. This review discusses the current evidence regarding the contribution of severe hypoxia to CNS injuries, with an emphasis on HIF-1α-mediated pathways. During severe hypoxia in the CNS, HIF-1α facilitates inflammasome formation, mitochondrial dysfunction, and cell death. This review presents the molecular mechanisms by which HIF-1α is involved in the pathogenesis of CNS injuries, such as stroke, traumatic brain injury, and Alzheimer's disease. Deciphering the molecular mechanisms of HIF-1α will contribute to the development of therapeutic strategies for severe hypoxic brain diseases.
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Affiliation(s)
- Yoon Kyung Choi
- Department of Integrative Bioscience and Biotechnology, Konkuk University, Seoul 05029, Republic of Korea
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Zhang Y, Weng J, Huan L, Sheng S, Xu F. Mitophagy in atherosclerosis: from mechanism to therapy. Front Immunol 2023; 14:1165507. [PMID: 37261351 PMCID: PMC10228545 DOI: 10.3389/fimmu.2023.1165507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 04/12/2023] [Indexed: 06/02/2023] Open
Abstract
Mitophagy is a type of autophagy that can selectively eliminate damaged and depolarized mitochondria to maintain mitochondrial activity and cellular homeostasis. Several pathways have been found to participate in different steps of mitophagy. Mitophagy plays a significant role in the homeostasis and physiological function of vascular endothelial cells, vascular smooth muscle cells, and macrophages, and is involved in the development of atherosclerosis (AS). At present, many medications and natural chemicals have been shown to alter mitophagy and slow the progression of AS. This review serves as an introduction to the field of mitophagy for researchers interested in targeting this pathway as part of a potential AS management strategy.
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Affiliation(s)
- Yanhong Zhang
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jiajun Weng
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Traditional Chinese Medicine Clinical Medical School (Xiyuan), Peking University, Beijing, China
- Department of Integrated Traditional and Western Medicine, Peking University Health Science Center, Beijing, China
| | - Luyao Huan
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Song Sheng
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Fengqin Xu
- Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- Traditional Chinese Medicine Clinical Medical School (Xiyuan), Peking University, Beijing, China
- Department of Integrated Traditional and Western Medicine, Peking University Health Science Center, Beijing, China
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Li T, Fei J, Yu H, Wang X, Bai J, Chen F, Li D, Yin Z. High glucose induced HIF-1α/TREK1 expression and myometrium relaxation during pregnancy. Front Endocrinol (Lausanne) 2023; 14:1115619. [PMID: 36909311 PMCID: PMC9998977 DOI: 10.3389/fendo.2023.1115619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 02/13/2023] [Indexed: 03/14/2023] Open
Abstract
Background The incidence of gestational diabetes mellitus (GDM) is increasing worldwide. GDM patients have a significantly higher rate of cesarean section and postpartum hemorrhage, suggesting changes in uterine contractility. TWIK-1-related potassium channel (TREK1) expressed in the pregnant uterus and its role in uterine contraction. In this study, we examined the expression of HIF-1α and TREK1 proteins in GDM uterine and investigated whether high glucose levels are involved in the regulation of human uterine smooth muscle cells (HUSMCs) contraction through TREK1, and verified the role of HIF-1α in this process. Methods Compared the uterine contractility between GDM and normal patients undergoing elective lower segment cesarean section. The HUSMCs were divided into normal glucose group, high glucose group, normal glucose with CoCl2 group, CoCl2 with echinomycin/L-Methionine group, and high glucose with echinomycin/L-Methionine group; Compare the cell contractility of each group. Compared the expression of hypoxia-inducible factor-1α (HIF-1α) and TREK1 protein in each group. Results The contractility of human uterine strips induced by both KCl and oxytocin was significantly lower in patients with GDM compared with that in normal individuals, with increased TREK1 and HIF-1α protein expression. The contractility of cultured HUSMCs was significantly decreased under high glucose levels, which was consistent with increased expression of HIF-1α and TREK1 proteins. The contractility of HUSMCs was decreased when hypoxia was induced by CoCl2 and increased when hypoxia was inhibited by echinomycin. The TREK1 inhibitor L-methionine also recovered the decreased contractility of HUSMCs under high glucose levels or hypoxia. Discussion The high glucose levels decreased the contractility of the myometrium, and increased expression of HIF-1a and TREK1 proteins play a role in changes in uterus contractility.
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Affiliation(s)
- Tengteng Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- Department of Obstetrics and Gynecology, Chaohu Hospital of Anhui Medical University, Chaohu, China
| | - Jiajia Fei
- Department of Scientific Research, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Huihui Yu
- Department of Scientific Research, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xingxing Wang
- Department of Scientific Research, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jingjing Bai
- Department of Obstetrics and Gynecology, Chaohu Hospital of Anhui Medical University, Chaohu, China
| | - Fucai Chen
- Department of Obstetrics and Gynecology, Chaohu Hospital of Anhui Medical University, Chaohu, China
| | - Dan Li
- Department of Scientific Research, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zongzhi Yin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- Department of Scientific Research, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- National Health Commission (NHC) Key Laboratory of the Study of Abnormal Gametes and the Reproductive Tract, Anhui Medical University, Hefei, China
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Rastogi S, Aldosary S, Saeedan AS, Ansari MN, Singh M, Kaithwas G. NF-κB mediated regulation of tumor cell proliferation in hypoxic microenvironment. Front Pharmacol 2023; 14:1108915. [PMID: 36891273 PMCID: PMC9986608 DOI: 10.3389/fphar.2023.1108915] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/01/2023] [Indexed: 02/22/2023] Open
Abstract
Hypoxia is caused by a cancer-promoting milieu characterized by persistent inflammation. NF-κB and HIF-1α are critical participants in this transition. Tumor development and maintenance are aided by NF-κB, while cellular proliferation and adaptability to angiogenic signals are aided by HIF-1α. Prolyl hydroxylase-2 (PHD-2) has been hypothesized to be the key oxygen-dependent regulator of HIF-1α and NF-transcriptional B's activity. Without low oxygen levels, HIF-1α is degraded by the proteasome in a process dependent on oxygen and 2-oxoglutarate. As opposed to the normal NF-κB activation route, where NF-κB is deactivated by PHD-2-mediated hydroxylation of IKK, this method actually activates NF-κB. HIF-1α is protected from degradation by proteasomes in hypoxic cells, where it then activates transcription factors involved in cellular metastasis and angiogenesis. The Pasteur phenomenon causes lactate to build up inside the hypoxic cells. As part of a process known as lactate shuttle, MCT-1 and MCT-4 cells help deliver lactate from the blood to neighboring, non-hypoxic tumour cells. Non-hypoxic tumour cells use lactate, which is converted to pyruvate, as fuel for oxidative phosphorylation. OXOPHOS cancer cells are characterized by a metabolic switch from glucose-facilitated oxidative phosphorylation to lactate-facilitated oxidative phosphorylation. Although PHD-2 was found in OXOPHOS cells. There is no clear explanation for the presence of NF-kappa B activity. The accumulation of the competitive inhibitor of 2-oxo-glutarate, pyruvate, in non-hypoxic tumour cells is well established. So, we conclude that PHD-2 is inactive in non-hypoxic tumour cells due to pyruvate-mediated competitive suppression of 2-oxo-glutarate. This results in canonical activation of NF-κB. In non-hypoxic tumour cells, 2-oxoglutarate serves as a limiting factor, rendering PHD-2 inactive. However, FIH prevents HIF-1α from engaging in its transcriptional actions. Using the existing scientific literature, we conclude in this study that NF-κB is the major regulator of tumour cell growth and proliferation via pyruvate-mediated competitive inhibition of PHD-2.
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Affiliation(s)
- Shubham Rastogi
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
| | - Sara Aldosary
- Department of Pharmaceutical Sciences, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Abdulaziz S Saeedan
- Department of Pharmacology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Mohd Nazam Ansari
- Department of Pharmacology, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Manjari Singh
- Department of Pharmaceutical Sciences, Assam Central University, Silchar, India
| | - Gaurav Kaithwas
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University, Lucknow, Uttar Pradesh, India
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Abstract
ABSTRACT
Hypoxia is one of the strongest environmental drivers of cellular and physiological adaptation. Although most mammals are largely intolerant of hypoxia, some specialized species have evolved mitigative strategies to tolerate hypoxic niches. Among the most hypoxia-tolerant mammals are naked mole-rats (Heterocephalus glaber), a eusocial species of subterranean rodent native to eastern Africa. In hypoxia, naked mole-rats maintain consciousness and remain active despite a robust and rapid suppression of metabolic rate, which is mediated by numerous behavioural, physiological and cellular strategies. Conversely, hypoxia-intolerant mammals and most other hypoxia-tolerant mammals cannot achieve the same degree of metabolic savings while staying active in hypoxia and must also increase oxygen supply to tissues, and/or enter torpor. Intriguingly, recent studies suggest that naked mole-rats share many cellular strategies with non-mammalian vertebrate champions of anoxia tolerance, including the use of alternative metabolic end-products and potent pH buffering mechanisms to mitigate cellular acidification due to upregulation of anaerobic metabolic pathways, rapid mitochondrial remodelling to favour increased respiratory efficiency, and systemic shifts in energy prioritization to maintain brain function over that of other tissues. Herein, I discuss what is known regarding adaptations of naked mole-rats to a hypoxic lifestyle, and contrast strategies employed by this species to those of hypoxia-intolerant mammals, closely related African mole-rats, other well-studied hypoxia-tolerant mammals, and non-mammalian vertebrate champions of anoxia tolerance. I also discuss the neotenic theory of hypoxia tolerance – a leading theory that may explain the evolutionary origins of hypoxia tolerance in mammals – and highlight promising but underexplored avenues of hypoxia-related research in this fascinating model organism.
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Affiliation(s)
- Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada, K1N 9A7. University of Ottawa, Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, Canada, K1H 8M5
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Zuhra K, Szabo C. The two faces of cyanide: an environmental toxin and a potential novel mammalian gasotransmitter. FEBS J 2021; 289:2481-2515. [PMID: 34297873 PMCID: PMC9291117 DOI: 10.1111/febs.16135] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 07/15/2021] [Accepted: 07/22/2021] [Indexed: 12/16/2022]
Abstract
Cyanide is traditionally viewed as a cytotoxic agent, with its primary mode of action being the inhibition of mitochondrial Complex IV (cytochrome c oxidase). However, recent studies demonstrate that the effect of cyanide on Complex IV in various mammalian cells is biphasic: in lower concentrations (nanomolar to low micromolar) cyanide stimulates Complex IV activity, increases ATP production and accelerates cell proliferation, while at higher concentrations (high micromolar to low millimolar) it produces the previously known (‘classic’) toxic effects. The first part of the article describes the cytotoxic actions of cyanide in the context of environmental toxicology, and highlights pathophysiological conditions (e.g., cystic fibrosis with Pseudomonas colonization) where bacterially produced cyanide exerts deleterious effects to the host. The second part of the article summarizes the mammalian sources of cyanide production and overviews the emerging concept that mammalian cells may produce cyanide, in low concentrations, to serve biological regulatory roles. Cyanide fulfills many of the general criteria as a ‘classical’ mammalian gasotransmitter and shares some common features with the current members of this class: nitric oxide, carbon monoxide, and hydrogen sulfide.
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Affiliation(s)
- Karim Zuhra
- Chair of Pharmacology, Section of Medicine, University of Fribourg, Switzerland
| | - Csaba Szabo
- Chair of Pharmacology, Section of Medicine, University of Fribourg, Switzerland
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Mesenteric Lymph Duct Drainage Attenuates Lung Inflammatory Injury and Inhibits Endothelial Cell Apoptosis in Septic Rats. BIOMED RESEARCH INTERNATIONAL 2020; 2020:3049302. [PMID: 33145344 PMCID: PMC7596461 DOI: 10.1155/2020/3049302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/06/2020] [Accepted: 08/13/2020] [Indexed: 01/19/2023]
Abstract
The present study was to investigate the effect of mesenteric lymph duct drainage on lung inflammatory response, histological alteration, and endothelial cell apoptosis in septic rats. Animals were randomly assigned into four groups: control, sham surgery, sepsis, and sepsis plus mesenteric lymph drainage. We used the colon ascendens stent peritonitis (CASP) procedure to induce the septic model in rats, and mesenteric lymph drainage was performed with a polyethylene (PE) catheter inserted into mesenteric lymphatic. The animals were sacrificed at the end of CASP in 6 h. The mRNA expression levels of inflammatory mediators were measured by qPCR, and the histologic damage were evaluated by the pathological score method. It was found that mesenteric lymph drainage significantly reduced the expression of TNF-α, IL-1β, and IL-6 mRNA in the lung. Pulmonary interstitial edema and infiltration of inflammatory cells were alleviated by mesenteric lymph drainage. Moreover, increased mRNA levels of TNF-α, IL-1β, IL-6 mRNA, and apoptotic rate were observed in PMVECs treated with septic lymph. These results indicate that mesenteric lymph duct drainage significantly attenuated lung inflammatory injury by decreasing the expression of pivotal inflammatory mediators and inhibiting endothelial apoptosis to preserve the pulmonary barrier function in septic rats.
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Sainani SR, Pansare PA, Rode K, Bhalchim V, Doke R, Desai S. Emendation of autophagic dysfuction in neurological disorders: a potential therapeutic target. Int J Neurosci 2020; 132:466-482. [PMID: 32924706 DOI: 10.1080/00207454.2020.1822356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Neurological disorders have been continuously contributing to the global disease burden and affect millions of people worldwide. Researchers strive hard to extract out the ultimate cure and serve for the betterment of the society, and yet the treatments available provide only symptomatic relief. Aging and abnormal mutations seem to be the major culprits responsible for neurotoxicity and neuronal death. One of the major causes of these neurological disorders that has been paid utmost attention recently, is Autophagic Dysfunction. AIM The aim of the study was to understand the autophagic process, its impairment in neurological disorders and targeting the impairments as a therapeutic option for the said disorders. METHODS For the purpose of review, we carried out an extensive literature study to excerpt the series of steps involved in autophagy and to understand the mechanism of autophagic impairment occurring in a range of neurodegenerative and neuropsychiatric disorders like Parkinson, Alzheimer, Depression, Schizophrenia, Autism etc. The review also involved the exploration of certain molecules that can help in triggering the compromised autophagic members. RESULTS We found that, a number of genes, proteins, receptors and transcription factors interplay to bring about autophagy and plethora of neurological disorders are associated with the diminished expression of one or more autophagic member leading to inhibition of autophagy. CONCLUSION Autophagy is a significant process for the removal of misfolded, abnormal, damaged protein aggregates and nonfunctional cell organelles in order to suppress neurodegeneration. Therefore, triggering autophagy could serve as an important therapeutic target to treat neurological disorders.
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Affiliation(s)
- Shivani R Sainani
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
| | - Prajakta A Pansare
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
| | - Ketki Rode
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
| | - Vrushali Bhalchim
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
| | - Rohit Doke
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
| | - Shivani Desai
- Department of Pharmacology, Dr D Y Patil Institute of Pharmaceutical Sciences and Research, Pune, India
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9
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Talla U, Bozonet SM, Parker HA, Hampton MB, Vissers MCM. Prolonged exposure to hypoxia induces an autophagy-like cell survival program in human neutrophils. J Leukoc Biol 2019; 106:1367-1379. [PMID: 31412152 DOI: 10.1002/jlb.4a0319-079rr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/14/2019] [Accepted: 07/14/2019] [Indexed: 12/13/2022] Open
Abstract
Neutrophils contribute to low oxygen availability at inflammatory sites through the generation of reactive oxidants. They are also functionally affected by hypoxia, which delays neutrophil apoptosis. However, the eventual fate of neutrophils in hypoxic conditions is unknown and this is important for their effective clearance and the resolution of inflammation. We have monitored the survival and function of normal human neutrophils exposed to hypoxia over a 48 h period. Apoptosis was delayed, and the cells remained intact even at 48 h. However, hypoxia promoted significant changes in neutrophil morphology with the appearance of many new cytoplasmic vesicles, often containing cell material, within 5 hours of exposure to low O2 . This coincided with an increase in LC3B-II expression, indicative of autophagosome formation and an autophagy-like process. In hypoxic conditions, neutrophils preferentially lost myeloperoxidase, a marker of azurophil granules. Short-term (2 h) hypoxic exposure resulted in sustained potential to generate superoxide when O2 was restored, but the capacity for oxidant production was lost with longer periods of hypoxia. Phagocytic ability was unchanged by hypoxia, and bacterial killing by neutrophils in both normoxic and hypoxic conditions was substantially diminished after 24 hours. However, pre-exposure to hypoxia resulted in an enhanced ability to kill bacteria by oxidant-independent mechanisms. Our data provide the first evidence for hypoxia as a driver of neutrophil autophagy that can influence the function and ultimate fate of these cells, including their eventual clearance and the resolution of inflammation.
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Affiliation(s)
- Usharani Talla
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Stephanie M Bozonet
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Heather A Parker
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Mark B Hampton
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Margreet C M Vissers
- Centre for Free Radical Research, Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
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Zhu L, Qi B, Hou D. Roles of HIF1α- and HIF2α-regulated BNIP3 in hypoxia-induced injury of neurons. Pathol Res Pract 2019; 215:822-827. [DOI: 10.1016/j.prp.2019.01.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/03/2019] [Accepted: 01/17/2019] [Indexed: 12/19/2022]
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Mylonis I, Simos G, Paraskeva E. Hypoxia-Inducible Factors and the Regulation of Lipid Metabolism. Cells 2019; 8:cells8030214. [PMID: 30832409 PMCID: PMC6468845 DOI: 10.3390/cells8030214] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 02/24/2019] [Accepted: 02/26/2019] [Indexed: 02/06/2023] Open
Abstract
Oxygen deprivation or hypoxia characterizes a number of serious pathological conditions and elicits a number of adaptive changes that are mainly mediated at the transcriptional level by the family of hypoxia-inducible factors (HIFs). The HIF target gene repertoire includes genes responsible for the regulation of metabolism, oxygen delivery and cell survival. Although the involvement of HIFs in the regulation of carbohydrate metabolism and the switch to anaerobic glycolysis under hypoxia is well established, their role in the control of lipid anabolism and catabolism remains still relatively obscure. Recent evidence indicates that many aspects of lipid metabolism are modified during hypoxia or in tumor cells in a HIF-dependent manner, contributing significantly to the pathogenesis and/or progression of cancer and metabolic disorders. However, direct transcriptional regulation by HIFs has been only demonstrated in relatively few cases, leaving open the exact and isoform-specific mechanisms that underlie HIF-dependency. This review summarizes the evidence for both direct and indirect roles of HIFs in the regulation of genes involved in lipid metabolism as well as the involvement of HIFs in various diseases as demonstrated by studies with transgenic animal models.
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Affiliation(s)
- Ilias Mylonis
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece.
| | - George Simos
- Laboratory of Biochemistry, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece.
- Gerald Bronfman Department of Oncology, Faculty of Medicine, McGill University, Montreal, QC H4A 3T2, Canada.
| | - Efrosyni Paraskeva
- Laboratory of Physiology, Faculty of Medicine, University of Thessaly, BIOPOLIS, 41500 Larissa, Greece.
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Dong Y, Li F, Shen H, Lu R, Yin S, Yang Q, Li Z, Wang S. Evaluation of the water disinfection by-product dichloroacetonitrile-induced biochemical, oxidative, histopathological, and mitochondrial functional alterations: Subacute oral toxicity in rats. Toxicol Ind Health 2017; 34:158-168. [PMID: 29226783 DOI: 10.1177/0748233717744720] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dichloroacetonitrile (DCAN), an emerging nitrogenous disinfection by-product, is more genotoxic and cytotoxic than the currently regulated carbonaceous disinfection by-products such as haloacetic acids. Few mechanistic studies have been conducted on the hepatic and renal toxicities of DCAN. This study examined the clinical biochemical, hematological, histopathological, oxidative, and mitochondrial functional alterations to evaluate the systematic toxicity after subacute oral exposure of 11 or 44 mg/kg/day in rats for 28 days. Body and spleen weights were lower, and organ-to-body weight ratios of the liver and kidney were higher in rats administered 44-mg/kg DCAN than in controls. The activities of serum alanine aminotransferase and alkaline phosphatase, and concentrations of blood serum urea nitrogen and retinol-binding protein were increased in rats administered 44-mg/kg DCAN compared with those of controls, thereby indicating hepatic and renal damage in this group. This was confirmed by histopathological alterations, including hepatic sinus dilation, extensive hemorrhage, vacuolar degeneration in the liver and glomerulus hemorrhage, and renal tubular swelling, in DCAN-exposed rats. Exposure to 44-mg/kg DCAN induced hepatic oxidative damage shown by the significant increase in malonaldehyde levels, a poisonous product of lipid peroxidation. Exposure to 44-mg/kg DCAN significantly increased hepatic glutathione content and mitochondrial bioenergy as noted by the elevation of mitochondrial membrane potential and cytochrome c oxidase activity, which might be attributed to compensatory pathophysiologic responses to DCAN-induced hepatic mitochondrial damage.
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Affiliation(s)
- Ying Dong
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Fang Li
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Haijun Shen
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Rongzhu Lu
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Siqi Yin
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Qi Yang
- 2 Department of Pathology, Zhenjiang First people's Hospital, Zhenjiang, Jiangsu, China
| | - Zhuangfa Li
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Suhua Wang
- 1 School of Medicine, Jiangsu University, Zhenjiang, Jiangsu, China
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Li F, Dong Y, Shen H, Lu R, Yin S, Tian W, Wang S, Xing G. Tolerance to dichloroacetonitrile-induced neurotoxicity in streptozotocin-induced diabetic rats. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2017; 56:61-67. [PMID: 28886427 DOI: 10.1016/j.etap.2017.08.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 08/20/2017] [Accepted: 08/24/2017] [Indexed: 06/07/2023]
Abstract
Diabetes mellitus has potential to alter the toxicity of hazardous chemicals. Dichloroacetonitrile (DCAN) is one of high-risk nitrogenous disinfection by-products. This study evaluated the neurotoxicity of DCAN (11, 44 and 88mg/kg) in normoglycaemic and streptozotocin (STZ)-induced diabetic rats via orally for 28days. STZ diabetes prolonged the median survival time and total lethal time after DCAN (88mg/kg) exposure when compared with that observed in normoglycaemic rats. DCAN altered motor activity and induced anxiety behaviour in normoglycaemic rats; but it did not exaggerate behavioural changes in STZ diabetic rats. DCAN -induced brain oxidative damage by compensatory increase glutathione content and decrease malonaldehyde levels; but it did not induce oxidative damage in diabetic rats. STZ diabetes slowed down the pathological pace of DCAN-induced brain mitochondrial dysfunction by decreasing reactive oxygen species and increasing cytochrome C oxidase activity. In conclusion, the present study indicated that STZ diabetic rats are resistant to DCAN-induced neurotoxicity at the dosage and with the dosage schedule in 28-day subacute toxicity test.
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Affiliation(s)
- Fang Li
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
| | - Ying Dong
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Haijun Shen
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Rongzhu Lu
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Siqi Yin
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Weihong Tian
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Suhua Wang
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
| | - Guangwei Xing
- School of Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, China
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Qiu GZ, Jin MZ, Dai JX, Sun W, Feng JH, Jin WL. Reprogramming of the Tumor in the Hypoxic Niche: The Emerging Concept and Associated Therapeutic Strategies. Trends Pharmacol Sci 2017; 38:669-686. [DOI: 10.1016/j.tips.2017.05.002] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/06/2017] [Accepted: 05/12/2017] [Indexed: 02/07/2023]
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He Z, Pu L, Yuan C, Jia M, Wang J. Nutrition deficiency promotes apoptosis of cartilage endplate stem cells in a caspase-independent manner partially through upregulating BNIP3. Acta Biochim Biophys Sin (Shanghai) 2017; 49:25-32. [PMID: 27864279 DOI: 10.1093/abbs/gmw111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 10/09/2016] [Indexed: 01/07/2023] Open
Abstract
Nutrition deficiency is reported to induce apoptosis of chondrocytes and degeneration of cartilage endplate (CEP) in rabbit. Cartilage endplate stem cells (CESCs) are important for the integrity of structure and function of CEP. Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3) has been reported to regulate apoptosis, autophagy, and cytoprotection. In this study, we aimed to determine whether nutrition deficiency induces apoptosis of CESCs, and whether or not the BNIP3-related pathway is activated in CESCs during nutrition deficiency. CESCs isolated from degenerated human CEP were cultured under normal or nutrition-deficient condition. Then, apoptosis was analyzed by flow cytometry. The expression and intracellular localization of BNIP3 were detected by quantitative real-time polymerase chain reaction, western blot analysis, and immunofluorescence assay, respectively. Mitochondrial membrane potential (MMP) and caspase-3 activity were measured by JC-1 staining and caspase-3 activity assay. Our results showed that nutrition deficiency promotes apoptosis and BNIP3 expression in CESCs. Notably, knockdown of BNIP3 could partially decrease nutrition deficiency-induced apoptosis of CESCs. In addition, nutrition deficiency could also induce upregulation of BNIP3, resulting in mitochondrial translocation of BNIP3 and loss of MMP in CESCs in a time-dependent manner. However, nutrition deficiency showed no effects on caspase-3 activity in CESCs. In summary, nutrition deficiency may promote CESC apoptosis partially through upregulating BNIP3, which might lead to activation of the BNIP3-related pathway and apoptosis of CESCs in a caspase-independent manner.
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Affiliation(s)
- Zhiliang He
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China
| | - Luqiao Pu
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China
| | - Chao Yuan
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China
| | - Min Jia
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China
| | - Jian Wang
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400038, China
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Iyalomhe O, Swierczek S, Enwerem N, Chen Y, Adedeji MO, Allard J, Ntekim O, Johnson S, Hughes K, Kurian P, Obisesan TO. The Role of Hypoxia-Inducible Factor 1 in Mild Cognitive Impairment. Cell Mol Neurobiol 2016; 37:969-977. [PMID: 27858285 DOI: 10.1007/s10571-016-0440-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 10/26/2016] [Indexed: 01/16/2023]
Abstract
Neuroinflammation and reactive oxygen species are thought to mediate the pathogenesis of Alzheimer's disease (AD), suggesting that mild cognitive impairment (MCI), a prodromal stage of AD, may be driven by similar insults. Several studies document that hypoxia-inducible factor 1 (HIF-1) is neuroprotective in the setting of neuronal insults, since this transcription factor drives the expression of critical genes that diminish neuronal cell death. HIF-1 facilitates glycolysis and glucose metabolism, thus helping to generate reductive equivalents of NADH/NADPH that counter oxidative stress. HIF-1 also improves cerebral blood flow which opposes the toxicity of hypoxia. Increased HIF-1 activity and/or expression of HIF-1 target genes, such as those involved in glycolysis or vascular flow, may be an early adaptation to the oxidative stressors that characterize MCI pathology. The molecular events that constitute this early adaptation are likely neuroprotective, and might mitigate cognitive decline or the onset of full-blown AD. On the other hand, prolonged or overwhelming stressors can convert HIF-1 into an activator of cell death through agents such as Bnip3, an event that is more likely to occur in late MCI or advanced Alzheimer's dementia.
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Affiliation(s)
- Osigbemhe Iyalomhe
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Sabina Swierczek
- Department of Hematology/BMT, University of Utah School of Medicine, 30 N Medical Dr, Salt Lake City, UT, 84132, USA
| | - Ngozi Enwerem
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Yuanxiu Chen
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Monica O Adedeji
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Joanne Allard
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Oyonumo Ntekim
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Sheree Johnson
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Kakra Hughes
- Division of Endovascular Surgery, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Philip Kurian
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA.,Human Genome Center, Howard University, 2041 Georgia Ave NW, Washington, DC, 20060, USA
| | - Thomas O Obisesan
- Geriatrics Division, Department of Medicine, Howard University Hospital, 2041 Georgia Ave NW, Washington, DC, 20060, USA. .,Howard University Clinical Research Unit (GHUCCTS CTSA), 2041 Georgia Ave, NW, Washington, DC, 20060, USA.
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Synergism of arsenic trioxide and MG132 in Raji cells attained by targeting BNIP3, autophagy, and mitochondria with low doses of valproic acid and vincristine. Eur J Cancer 2014; 50:3243-61. [DOI: 10.1016/j.ejca.2014.09.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/30/2014] [Accepted: 09/20/2014] [Indexed: 12/20/2022]
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Bulygina VV, Men’shanov PN, Lanshakov DA, Dygalo NN. The effects of dexamethasone and hypoxia on the content of active caspase-3 in the cerebellum and the behavior of neonatal rats. BIOL BULL+ 2014. [DOI: 10.1134/s1062359014060028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Wang B, Xiao JL, Ling YH, Meng XJ, Wu B, Yang XY, Zou F. BNIP3 upregulation by ERK and JNK mediates cadmium-induced necrosis in neuronal cells. Toxicol Sci 2014; 140:393-402. [PMID: 24824807 DOI: 10.1093/toxsci/kfu091] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cadmium (Cd) is a toxic heavy metal that may cause neurological disorders. We studied the mechanism underlying Cd-mediated cell death in neuronal cells. In Cd-induced neurotoxicity, caspase-3 was only modestly activated, and accordingly, zVAD-fmk, a pan-caspase inhibitor, partially attenuated cell death. However, pretreatment with Necrox-2 or Necrox-5, two novel necrosis inhibitors, suppressed cell death more markedly compared with pretreatment with zVAD-fmk. Moreover, the necrosis inhibitors did not prevent cleavage of caspase-3. These results indicate that caspase-independent necrosis is more prevalent in Cd-induced neurotoxicity. Bcl-2 and adenovirus E1B-19 kDa-interacting protein 3 (BNIP3) has been reported to be related to caspase-independent cell death. Cd treatment caused a dramatic upregulation of BNIP3 mRNA and protein levels in vitro and in vivo. Furthermore, knockdown of BNIP3 greatly inhibited Cd-induced cell death. Importantly, BNIP3 RNAi decreased lactate dehydrogenase release and the percentage of propidium iodide-positive cells, two markers of necrotic cell death due to rupture of the cell membrane, whereas it had no effect on activation of caspase-3 in Cd-treated cells. These data suggest that BNIP3 mediates caspase-independent necrosis, but not apoptosis. Moreover, our results indicate that induction of BNIP3 by Cd may not be related to HIF-1 which is generally regarded as a mediator responsible for BNIP3 expression. Finally, we show that mitogen-activated protein kinases (MAPKs) are activated by Cd in vitro and in vivo; ERK and JNK promote BNIP3 upregulation and subsequent necrosis. Taken together, our results suggest BNIP3, upregulated by activation of ERK and JNK, mediates Cd-induced necrosis in neuronal cells.
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Affiliation(s)
- Bin Wang
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Jia-Li Xiao
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Yi-Hui Ling
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xiao-Jing Meng
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Bing Wu
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Xin-Yi Yang
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
| | - Fei Zou
- Department of Occupational Heath and Occupational Medicine, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou, Guangdong 510515, China
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Dai Y, Li W, Zhong M, Chen J, Liu Y, Cheng Q, Li T. Preconditioning and post-treatment with cobalt chloride in rat model of perinatal hypoxic-ischemic encephalopathy. Brain Dev 2014; 36:228-40. [PMID: 23694759 DOI: 10.1016/j.braindev.2013.04.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 02/26/2013] [Accepted: 04/15/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Hypoxia-ischemia (HI)-induced perinatal encephalopathy is a major cause of acute mortality and chronic neurologic morbidities such as cerebral palsy, mental retardation, and epilepsy. As the essential transcription factor for the activation of hypoxia-inducible genes, hypoxia-inducible factor 1 alpha (HIF-1α) plays an important role in the pathophysiological response to the stress of HI brain damage. Whether HIF-1α activation promotes neuroprotection in HI tissues is controversial. METHODS The left common carotid artery of rats aged 7days was ligated under anesthesia. The pups were then exposed to hypoxia in a normobaric chamber filled with 8% oxygen and 92% nitrogen for 2.5h. In the sham control group, the left common carotid artery was exposed but was not ligated or exposed to hypoxia. To assess the time window for effective treatment, the HIF-1α inducer cobalt chloride (CoCl2) was injected subcutaneously 1day before surgery, immediately or 1day after surgery. The brain tissues were harvested from the pups of each groups at 1, 2 and 7days after insult for HIF-1α protein ant its target genes expression and for investigating the injury. Morris water maze tests were performed at postnatal 7weeks. RESULTS HIF-1α protein levels and its target genes vascular endothelial growth factor, heme oxygenase-1, and insulin-like growth factor 1 were markedly increased after intraperitoneal injection of CoCl2 (60mg/kg). The target gene inducible nitric oxide synthase exhibited a biphasic time course. HI caused apoptosis and reduced capillary density, which were ameliorated by CoCl2. Both preconditioning with CoCl2 24h before HI and administration of CoCl2 24h after HI improved long-term reference memory compared with that in vehicle-injected littermate controls. Administration of CoCl2 immediately after HI did not improve spatial working memory. CONCLUSIONS CoCl2 activates HIF-1α and protects against brain damage in vivo. The time of administration could be used to manipulate the activity of HIF-1α pathways and promote recovery.
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Affiliation(s)
- Ying Dai
- Department of Primary Child Health Care, Children's Hospital of Chongqing Medical University, PR China
| | - Wendi Li
- Children's Nutritional Research Center, Key Laboratory of Developmental Diseases in Childhood of Education Ministry, Key Laboratory of Pediatrics in Chongqing, CSTC2009CA5002, Chongqing International Science and Technology Cooperation Center for Child Development and Disorder, Children's Hospital of Chongqing Medical University, PR China
| | - Min Zhong
- Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Jie Chen
- Children's Nutritional Research Center, Key Laboratory of Developmental Diseases in Childhood of Education Ministry, Key Laboratory of Pediatrics in Chongqing, CSTC2009CA5002, Chongqing International Science and Technology Cooperation Center for Child Development and Disorder, Children's Hospital of Chongqing Medical University, PR China
| | - Youxue Liu
- Children's Nutritional Research Center, Key Laboratory of Developmental Diseases in Childhood of Education Ministry, Key Laboratory of Pediatrics in Chongqing, CSTC2009CA5002, Chongqing International Science and Technology Cooperation Center for Child Development and Disorder, Children's Hospital of Chongqing Medical University, PR China
| | - Qian Cheng
- Department of Primary Child Health Care, Children's Hospital of Chongqing Medical University, PR China
| | - Tingyu Li
- Department of Primary Child Health Care, Children's Hospital of Chongqing Medical University, PR China; Children's Nutritional Research Center, Key Laboratory of Developmental Diseases in Childhood of Education Ministry, Key Laboratory of Pediatrics in Chongqing, CSTC2009CA5002, Chongqing International Science and Technology Cooperation Center for Child Development and Disorder, Children's Hospital of Chongqing Medical University, PR China.
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Ji Q, Yang L, Zhou J, Lin R, Zhang J, Lin Q, Wang W, Zhang K. Protective effects of paeoniflorin against cobalt chloride-induced apoptosis of endothelial cells via HIF-1α pathway. Toxicol In Vitro 2012; 26:455-61. [DOI: 10.1016/j.tiv.2012.01.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 11/25/2011] [Accepted: 01/10/2012] [Indexed: 10/14/2022]
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Liu J, Wang J, Zhou Y. Upregulation of BNIP3 and translocation to mitochondria in nutrition deprivation induced apoptosis in nucleus pulposus cells. Joint Bone Spine 2012; 79:186-91. [DOI: 10.1016/j.jbspin.2011.04.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 04/19/2011] [Indexed: 01/04/2023]
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Kvietys PR, Granger DN. Role of reactive oxygen and nitrogen species in the vascular responses to inflammation. Free Radic Biol Med 2012; 52:556-592. [PMID: 22154653 PMCID: PMC3348846 DOI: 10.1016/j.freeradbiomed.2011.11.002] [Citation(s) in RCA: 213] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 11/04/2011] [Accepted: 11/04/2011] [Indexed: 12/23/2022]
Abstract
Inflammation is a complex and potentially life-threatening condition that involves the participation of a variety of chemical mediators, signaling pathways, and cell types. The microcirculation, which is critical for the initiation and perpetuation of an inflammatory response, exhibits several characteristic functional and structural changes in response to inflammation. These include vasomotor dysfunction (impaired vessel dilation and constriction), the adhesion and transendothelial migration of leukocytes, endothelial barrier dysfunction (increased vascular permeability), blood vessel proliferation (angiogenesis), and enhanced thrombus formation. These diverse responses of the microvasculature largely reflect the endothelial cell dysfunction that accompanies inflammation and the central role of these cells in modulating processes as varied as blood flow regulation, angiogenesis, and thrombogenesis. The importance of endothelial cells in inflammation-induced vascular dysfunction is also predicated on the ability of these cells to produce and respond to reactive oxygen and nitrogen species. Inflammation seems to upset the balance between nitric oxide and superoxide within (and surrounding) endothelial cells, which is necessary for normal vessel function. This review is focused on defining the molecular targets in the vessel wall that interact with reactive oxygen species and nitric oxide to produce the characteristic functional and structural changes that occur in response to inflammation. This analysis of the literature is consistent with the view that reactive oxygen and nitrogen species contribute significantly to the diverse vascular responses in inflammation and supports efforts that are directed at targeting these highly reactive species to maintain normal vascular health in pathological conditions that are associated with acute or chronic inflammation.
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Affiliation(s)
- Peter R Kvietys
- College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - D Neil Granger
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71130-3932, USA.
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Huang Y, Yu J, Yan C, Hou J, Pu J, Zhang G, Fu Z, Wang X. Effect of small interfering RNA targeting hypoxia-inducible factor-1α on radiosensitivity of PC3 cell line. Urology 2011; 79:744.e17-24. [PMID: 22196409 DOI: 10.1016/j.urology.2011.10.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 10/14/2011] [Accepted: 10/14/2011] [Indexed: 01/17/2023]
Abstract
OBJECTIVE To evaluate the effect of silencing hypoxia-inducible factor-1α (HIF-1α) expression by small interfering RNA (siRNA) on the radiosensitivity of the PC3 cell line. METHODS The expression of HIF-1α in PC3, a p53-null and androgen-independent prostate cancer cell line, was knocked down by siRNA. Irradiation was performed at 48 hours after transfection. The cells were divided into 3 groups: the PC3 group, control group (transfected with scramble siRNA), and HIF-1α silence group. HIF-1α expression was determined using real-time polymerase chain reaction and Western immunoblotting. A clonogenic assay and the cell counting kit-8 assay were performed to determine the radiosensitivity. Flow cytometry was used to assess apoptosis and cell cycle distribution. RESULTS HIF-1α siRNA downregulated HIF-1α expression in PC3 cells on the mRNA level and protein level, and its silencing effect on mRNA level was evident at 24-72 hours. The HIF-1α silence group had a low final slope of exponential part of a radiation survival curve, survival fraction of 2 Gy, quasi-threshold dose, and extrapolation number, and the sensitizing enhancement ratio was 1.24. The cell counting kit-8 assay showed decreased cellular viability (24 hours, F = 139.74, P < .01; 48 hours, F = 495.49, P < .01; 72 hours, F = 426.89, P < .01; 96 hours, F = 471.11, P < .01) in the HIF-1α silence group. Silencing HIF-1α also induced more apoptosis (PC3, 17.9% ± 1.65%; control group, 18.6% ± 1.37%; HIF-1α silence group, 29.1% ± 2.16%; F = 169.9, P < .01) and cell cycle arrest at the S, G(2)/M phase. CONCLUSION The suppression of HIF-1α in PC3 cells sensitizes the PC3 cells to irradiation. We have shown that HIF-1α inhibition attenuates repair of postradiation injury, with an increase in both interphase death and reproductive death after irradiation, apoptotic potential, and cell cycle arrest at the proliferative phase.
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Affiliation(s)
- Yuhua Huang
- Department of Urology, First Affiliated Hospital of Soozhow University, Suzhou, Jiangsu, China
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Xu C, Wang J, Li J, Fang R. Expression of elongation factor (EF)-Tu is correlated with prognosis of gastric adenocarcinomas. Int J Mol Sci 2011; 12:6645-55. [PMID: 22072909 PMCID: PMC3211000 DOI: 10.3390/ijms12106645] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/16/2011] [Accepted: 09/22/2011] [Indexed: 12/21/2022] Open
Abstract
Altered expressions of mitochondria elongation factor Tu (EF-Tu) have been observed in certain types of cancers, including gastric cancer cell lines, but the impact of the alterations in gastric adenocarcinoma remains unclear. The purpose of this study was to investigate the expression of EF-Tu in gastric adenocarcinoma and to assess its clinical significance. A total of 104 paired resected gastric adenocarcinoma and corresponding normal specimens were collected in this study. EF-Tu expression was assessed by immunohistochemical staining. The correlation of EF-Tu expression and patients’ clinicopathological parameters was statically evaluated and the prognostic significance of EF-Tu expression was assessed by univariate and multivariate analyses. Forty-nine out of 104 (47.1%) gastric adenocarcinoma specimens showed high expression of EF-Tu, while the remaining 55 specimens showed weak or negative expression of EF-Tu. In contrast, EF-Tu high expression was detected in 62.5% (65 of 104) normal tissues. Down-regulation of EF-Tu was associated with serosal invasion (P = 0.042) and node involvement (P = 0.005), and down-regulation of EF-Tu was correlated with poor overall survival (P = 0.020). In curative resection (R0) patients, there were also significant differences (P = 0.043). In the multivariate analysis, the EF-Tu expression remained a significant independent prognostic factor (P = 0.038). Our results indicate that EF-Tu is expressed in both gastric adenocarcinoma and corresponding normal tissues. Down-regulation of EF-Tu expression is associated with advanced disease stage and EF-Tu expression maybe served as an independent prognostic factor.
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Affiliation(s)
- Chaoyang Xu
- Department of Breast and Thyroid Surgery, Shaoxing People’s Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, 312000, China
- Department of Surgical Oncology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310016, China
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86-571-86006912; Fax: +86-571-86044817
| | - Jianjun Wang
- Department of Surgical Oncology, The Chunan County First Hospital, Chunan, Zhejiang, 311700, China; E-Mails: (J.W.); (R.F.)
| | - Jiajia Li
- Department of Surgery, Shaoxing People’s Hospital, Shaoxing Hospital of Zhejiang University, Shaoxing, Zhejiang, 312000, China; E-Mail: (J.L.)
| | - Rengui Fang
- Department of Surgical Oncology, The Chunan County First Hospital, Chunan, Zhejiang, 311700, China; E-Mails: (J.W.); (R.F.)
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Correia SC, Santos RX, Cardoso SM, Santos MS, Oliveira CR, Moreira PI. Cyanide preconditioning protects brain endothelial and NT2 neuron-like cells against glucotoxicity: role of mitochondrial reactive oxygen species and HIF-1α. Neurobiol Dis 2011; 45:206-18. [PMID: 21854848 DOI: 10.1016/j.nbd.2011.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Revised: 07/27/2011] [Accepted: 08/03/2011] [Indexed: 01/06/2023] Open
Abstract
The current study was undertaken to address the role of mitochondrial reactive oxygen species (ROS), and hypoxia inducible factor-1 alpha (HIF-1α) signaling pathway in the protection against high glucose levels in brain endothelial and NT2 neuron-like cells. Rat brain endothelial cells (RBE4) treated with non-toxic concentrations of cyanide (≤1 μM; 1h) exhibited an increase in ROS levels, particularly hydrogen peroxide (H(2)O(2)). Cyanide also induced a modest mitochondrial depolarization, an increase in oxygen consumption and a structural (smaller mitochondria) and spatial (perinuclear region) reorganization of mitochondrial network. The stabilization and nuclear activation of HIF-1α in the presence of cyanide were also observed, which resulted in an increase in vascular endothelial growth factor (VEGF), endothelial nitric oxide synthase (eNOS) and erythropoietin (EPO) protein levels reflecting an adaptive response. Importantly, preconditioning induced by cyanide protected brain endothelial cells against high glucose-mediated damage by the prevention of apoptotic cell death. In mitochondrial DNA-depleted NT2 (NT2 ρ0) cells, cyanide (0.1 μM) was unable to stimulate ROS production and, consequently, protect against glucotoxicity. Conversely, in NT2 cells, the parental cells with functional mitochondria, cyanide significantly increased ROS levels protecting against high glucose-induced neuronal cell loss and activation of caspase-3. The free radical scavenger N-acetyl-L-cysteine and the specific HIF-1α inhibitor 2-methoxyestradiol completely abolished the protective effects of cyanide preconditioning. Altogether our results demonstrate that mitochondrial preconditioning induced by cyanide triggers a protective response mediated by mitochondrial ROS and HIF-1α activation and signaling, which render brain endothelial and neuronal cells resistant against glucotoxicity.
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Affiliation(s)
- Sónia C Correia
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
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Inducers of Chemical Hypoxia Act in a Gender- and Brain Region-Specific Manner on Primary Astrocyte Viability and Cytochrome c Oxidase. Neurotox Res 2010; 20:1-14. [DOI: 10.1007/s12640-010-9213-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Revised: 05/11/2010] [Accepted: 08/02/2010] [Indexed: 12/19/2022]
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Leavesley HB, Li L, Mukhopadhyay S, Borowitz JL, Isom GE. Nitrite-mediated antagonism of cyanide inhibition of cytochrome c oxidase in dopamine neurons. Toxicol Sci 2010; 115:569-76. [PMID: 20335280 DOI: 10.1093/toxsci/kfq084] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cyanide inhibits aerobic metabolism by binding to the binuclear heme center of cytochrome c oxidase (CcOX). Amyl nitrite and sodium nitrite (NaNO(2)) antagonize cyanide toxicity in part by oxidizing hemoglobin to methemoglobin (mHb), which then scavenges cyanide. mHb generation is thought to be a primary mechanism by which the NO(2)(-) ion antagonizes cyanide. On the other hand, NO(2)(-) can undergo biotransformation to generate nitric oxide (NO), which may then directly antagonize cyanide inhibition of CcOX. In this study, nitrite-mediated antagonism of cyanide inhibition of oxidative phosphorylation was examined in rat dopaminergic N27 cells. NaNO(2) produced a time- and concentration-dependent increase in whole-cell and mitochondrial levels of NO. The NO scavenger 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxy 3-oxide (PTIO) reversed this increase in cellular and mitochondrial NO. NO generated from NaNO(2) decreased cellular oxygen consumption and inhibited CcOX activity. PTIO reversed the NO-mediated inhibition, thus providing strong evidence that NO mediates the action of NaNO(2). Under similar conditions, KCN (20muM) inhibited cellular state-3 oxygen consumption and CcOX activity. Pretreatment with NaNO(2) reversed KCN-mediated inhibition of both oxygen consumption and CcOX activity. The NaNO(2) antagonism of cyanide was blocked by pretreatment with the NO scavenger PTIO. It was concluded that NaNO(2) antagonizes cyanide inhibition of CcOX by generating of NO, which then interacts directly with the binding of KCN x CcOX to reverse the toxicity. In vivo antagonism of cyanide by NO(2)(-) appears to be due to both generation of mHb and direct displacement of cyanide from CcOX by NO.
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Affiliation(s)
- Heather B Leavesley
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907-1333, USA
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Seyfried TN, Shelton LM. Cancer as a metabolic disease. Nutr Metab (Lond) 2010; 7:7. [PMID: 20181022 PMCID: PMC2845135 DOI: 10.1186/1743-7075-7-7] [Citation(s) in RCA: 382] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Accepted: 01/27/2010] [Indexed: 01/08/2023] Open
Abstract
Emerging evidence indicates that impaired cellular energy metabolism is the defining characteristic of nearly all cancers regardless of cellular or tissue origin. In contrast to normal cells, which derive most of their usable energy from oxidative phosphorylation, most cancer cells become heavily dependent on substrate level phosphorylation to meet energy demands. Evidence is reviewed supporting a general hypothesis that genomic instability and essentially all hallmarks of cancer, including aerobic glycolysis (Warburg effect), can be linked to impaired mitochondrial function and energy metabolism. A view of cancer as primarily a metabolic disease will impact approaches to cancer management and prevention.
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bcl-2/Adenovirus E1B 19-kd interacting protein 3 (BNIP3) regulates hypoxia-induced neural precursor cell death. J Neuropathol Exp Neurol 2009; 68:1326-38. [PMID: 19915483 DOI: 10.1097/nen.0b013e3181c3b9be] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Perinatal hypoxia-ischemia may result in long-term neurological deficits. In addition to producing neuron death, HI causes death of neural precursor cells (NPCs) in the developing brain. To characterize the molecular pathways that regulate hypoxia-induced death of NPCs, we treated a mouse neural stem cell line (C17.2 cells) and fibroblastic growth factor II-expanded primary NPCs derived from wild-type or gene-disrupted mice, with oxygen glucose deprivation or the hypoxia mimetics desferrioxamine or cobalt chloride. Neural precursor cells undergoing hypoxia exhibited time- and concentration-dependent caspase-3 activation and cell death, which was significantly reduced by treatment with a broad caspase inhibitor or protein synthesis inhibition. Bax/Bak-deficient NPCs were protected from desferrioxamine-induced death and exhibited minimal caspase-3 activation. Oxygen glucose deprivation or hypoxia-mimetic exposure also resulted in increased hypoxia-inducible factor alpha and bcl-2/adenovirus E1B 19-kd interacting protein 3 (BNIP3) expression. BNIP3 shRNA treatment failed to affect hypoxia-induced caspase-3 activation but inhibited cell death and nuclear translocation of apoptosis-inducing factor, indicating that BNIP3 is an important regulator of caspase-independent NPC death after hypoxia. These studies demonstrate that hypoxia activates both caspase-dependent and -independent NPC death pathways that are critically regulated by multiple Bcl-2 family members.
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S100A8/A9 induces autophagy and apoptosis via ROS-mediated cross-talk between mitochondria and lysosomes that involves BNIP3. Cell Res 2009; 20:314-31. [PMID: 19935772 DOI: 10.1038/cr.2009.129] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The complex formed by two members of the S100 calcium-binding protein family, S100A8/A9, exerts apoptosis-inducing activity in various cells of different origins. Here, we present evidence that the underlying molecular mechanisms involve both programmed cell death I (PCD I, apoptosis) and PCD II (autophagy)-like death. Treatment of cells with S100A8/A9 caused the increase of Beclin-1 expression as well as Atg12-Atg5 formation. S100A8/A9-induced cell death was partially inhibited by the specific PI3-kinase class III inhibitor, 3-methyladenine (3-MA), and by the vacuole H(+)-ATPase inhibitor, bafilomycin-A1 (Baf-A1). S100A8/A9 provoked the translocation of BNIP3, a BH3 only pro-apoptotic Bcl2 family member, to mitochondria. Consistent with this finding, DeltaTM-BNIP3 overexpression partially inhibited S100A8/A9-induced cell death, decreased reactive oxygen species (ROS) generation, and partially protected against the decrease in mitochondrial transmembrane potential in S100A8/A9-treated cells. In addition, either DeltaTM-BNIP3 overexpression or N-acetyl-L-cysteine co-treatment decreased lysosomal activation in cells treated with S100A8/A9. Our data indicate that S100A8/A9-promoted cell death occurs through the cross-talk of mitochondria and lysosomes via ROS and the process involves BNIP3.
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Zhang L, Li L, Leavesley HW, Zhang X, Borowitz JL, Isom GE. Cyanide-induced apoptosis of dopaminergic cells is promoted by BNIP3 and Bax modulation of endoplasmic reticulum-mitochondrial Ca2+ levels. J Pharmacol Exp Ther 2009; 332:97-105. [PMID: 19841471 DOI: 10.1124/jpet.109.159103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cyanide is a potent neurotoxicant that can produce dopaminergic neuronal death in the substantia nigra and is associated with a Parkinson-like syndrome. In this study involvement of Bcl-2/adenovirus E1B 19-kDa interacting protein 3 (BNIP3), a BH3-only Bcl-2 protein, in cyanide-induced death of dopaminergic cells was determined in mice and Mes 23.5 cells. Treatment of mice with cyanide up-regulated BNIP3 and Bax expression in tyrosine hydroxylase (TH)-positive cells of the substantia nigra, and progressive loss of TH-positive neurons was observed over a 9-day period. In Mes 23.5 dopaminergic cells, cyanide stimulated translocalization of BNIP3 to both endoplasmic reticulum (ER) and mitochondria. In ER, BNIP3 stimulated release of Ca(2+) into the cytosol, followed by accumulation of mitochondrial Ca(2+), resulting in reduction of mitochondrial membrane potential (Deltapsi(m)) and eventually cell death. Cyanide also activated Bax to colocalize with BNIP3 in ER and mitochondria. Forced overexpression of BNIP3 activated Bax, whereas gene silencing reduced Bax activity. Knockdown of Bax expression by small interfering RNA blocked the BNIP3-mediated changes in ER and mitochondrial Ca(2+) to block cyanide-induced mitochondrial dysfunction and cell death. These findings show that BNIP3-mediates cyanide-induced dopaminergic cell death through a Bax downstream signal that mobilizes ER Ca(2+) stores, followed by mitochondrial Ca(2+) overload.
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Affiliation(s)
- Lu Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-1333, USA
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Devalaraja-Narashimha K, Diener AM, Padanilam BJ. Cyclophilin D gene ablation protects mice from ischemic renal injury. Am J Physiol Renal Physiol 2009; 297:F749-59. [PMID: 19553348 DOI: 10.1152/ajprenal.00239.2009] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Increased oxidative stress and intracellular calcium levels and mitochondrial overloading of calcium during ischemic renal injury (IRI) favor mitochondrial membrane permeability transition pore (MPTP) opening and subsequent necrotic cell death. Cyclophilin D (CypD) is an essential component of MPTP, and recent findings implicate its role in necrotic, but not apoptotic, cell death. To evaluate the role of CypD following IRI, we tested the hypothesis that CypD gene ablation protects mice from IRI. Renal function as assessed by plasma levels of both creatinine and blood urea nitrogen was significantly reduced in CypD knockout (CypD(-/-)) mice compared with wild-type mice during the 5-day post-ischemia period. Erythrocyte trapping, tubular cell necrosis, tubular dilatation, and neutrophil infiltration were significantly decreased in CypD(-/-) mice. To define the mechanisms by which CypD deficiency protect the kidneys, an in vitro model of IRI was employed. Inhibition of CypD using cyclosporin A in oxidant-injured cultured proximal tubular cells (PTC) prevented mitochondrial membrane depolarization, reduced LDH release, ATP depletion and necrotic cell death. Similarly, oxidant-injured CypD(-/-) PTC primary cultures were protected from cytotoxicity and necrosis. To conclude, CypD gene ablation offers both functional and morphological protection in mice following IRI by decreasing necrotic cell death possibly via inhibition of MPTP and ATP depletion.
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Zhang X, Li L, Zhang L, Borowitz JL, Isom GE. Cyanide-induced death of dopaminergic cells is mediated by uncoupling protein-2 up-regulation and reduced Bcl-2 expression. Toxicol Appl Pharmacol 2009; 238:11-9. [PMID: 19361538 PMCID: PMC2696033 DOI: 10.1016/j.taap.2009.03.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Revised: 03/27/2009] [Accepted: 03/28/2009] [Indexed: 01/11/2023]
Abstract
Cyanide is a potent inhibitor of mitochondrial oxidative metabolism and produces mitochondria-mediated death of dopaminergic neurons and sublethal intoxications that are associated with a Parkinson-like syndrome. Cyanide toxicity is enhanced when mitochondrial uncoupling is stimulated following up-regulation of uncoupling protein-2 (UCP-2). In this study, the role of a pro-survival protein, Bcl-2, in cyanide-mediated cell death was determined in a rat dopaminergic immortalized mesencephalic cell line (N27 cells). Following pharmacological up-regulation of UCP-2 by treatment with Wy14,643, cyanide reduced cellular Bcl-2 expression by increasing proteasomal degradation of the protein. The increased turnover of Bcl-2 was mediated by an increase of oxidative stress following UCP-2 up-regulation. The oxidative stress involved depletion of mitochondrial glutathione (mtGSH) and increased H2O2 generation. Repletion of mtGSH by loading cells with glutathione ethyl ester reduced H2O2 generation and in turn blocked the cyanide-induced decrease of Bcl-2. To determine if UCP-2 mediated the response, RNAi knock down was conducted. The RNAi decreased cyanide-induced depletion of mtGSH, reduced H2O2 accumulation, and inhibited down-regulation of Bcl-2, thus blocking cell death. To confirm the role of Bcl-2 down-regulation in the cell death, it was shown that over-expression of Bcl-2 by cDNA transfection attenuated the enhancement of cyanide toxicity after UCP-2 up-regulation. It was concluded that UCP-2 up-regulation sensitizes cells to cyanide by increasing cellular oxidative stress, leading to an increase of Bcl-2 degradation. Then the reduced Bcl-2 levels sensitize the cells to cyanide-mediated cell death.
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Affiliation(s)
- X Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-1333, USA
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Zhang L, Li L, Liu H, Borowitz JL, Isom GE. BNIP3 mediates cell death by different pathways following localization to endoplasmic reticulum and mitochondrion. FASEB J 2009; 23:3405-14. [PMID: 19535684 DOI: 10.1096/fj.08-124354] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BNIP3 (Bcl-2/adenovirus E1B 19-kDa interacting protein 3) is a BH3-only proapoptotic member of the Bcl-2 family. Because the interaction of Bcl-2 proteins with intracellular Ca(2+) stores has been linked to apoptosis, the role of Ca(2+) transfer between endoplasmic reticulum (ER) and mitochondria in BNIP3-mediated cell death was determined in a rat dopaminergic neuronal cell line, Mes 23.5. BNIP3 mutants were constructed to target either ER or mitochondria. Localization of BNIP3 to the ER membrane facilitated release of Ca(2+) and subsequently increased uptake of Ca(2+) into mitochondria. Excessive accumulation of mitochondrial Ca(2+) decreased mitochondrial membrane potential (DeltaPsi(m)), resulting in execution of a caspase-independent cell death. Reduction of ER Ca(2+) induced by ER-targeted BNIP3 and the subsequent cell death was blocked by the antiapoptotic protein, Bcl-2. On the other hand, mitochondria-targeted BNIP3 initiated apoptosis by a Ca(2+)-independent mechanism by inducing mitochondrial pore transition and dissipation of DeltaPsi(m). The disruption of DeltaPsi(m) and cell death was not blocked by Bcl-2 overexpression. These findings show that BNIP3 undergoes a dual subcellular localization and initiates different cell death signaling events in the ER and mitochondria. Bcl-2 counters the BNIP3-initiated mobilization of ER Ca(2+) depletion to reduce the level of apoptosis.
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Affiliation(s)
- Lu Zhang
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-1333, USA
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Metukuri MR, Beer-Stolz D, Namas RA, Dhupar R, Torres A, Loughran PA, Jefferson BS, Tsung A, Billiar TR, Vodovotz Y, Zamora R. Expression and subcellular localization of BNIP3 in hypoxic hepatocytes and liver stress. Am J Physiol Gastrointest Liver Physiol 2009; 296:G499-509. [PMID: 19147804 PMCID: PMC2660177 DOI: 10.1152/ajpgi.90526.2008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have previously demonstrated that the Bcl-2/adenovirus EIB 19-kDa interacting protein 3 (BNIP3), a cell death-related member of the Bcl-2 family, is upregulated in vitro and in vivo in both experimental and clinical settings of redox stress and that nitric oxide (NO) downregulates its expression. In this study we sought to examine the expression and localization of BNIP3 in murine hepatocytes and in a murine model of hemorrhagic shock (HS) and ischemia-reperfusion (I/R). Freshly isolated mouse hepatocytes were exposed to 1% hypoxia for 6 h followed by reoxygenation for 18 h, and protein was isolated for Western blot analysis. Hepatocytes grown on coverslips were fixed for localization studies. Similarly, livers from surgically cannulated C57Bl/6 mice and from mice cannulated and subjected to 1-4 h of HS were processed for protein isolation and Western blot analysis. In hepatocytes, BNIP3 was expressed constitutively but was upregulated under hypoxic conditions, and this upregulation was countered by treatment with a NO donor. Surprisingly, BNIP3 was localized in the nucleus of normoxic hepatocytes, in the cytoplasm following hypoxia, and again in the nucleus following reoxygenation. Upregulation of BNIP3 partially required p38 MAPK activation. BNIP3 contributed to hypoxic injury in hepatocytes, since this injury was diminished by knockdown of BNIP3 mRNA. Hepatic BNIP3 was also upregulated in two different models of liver stress in vivo, suggesting that a multitude of inflammatory stresses can lead to the modulation of BNIP3. In turn, the upregulation of BNIP3 appears to be one mechanism of hepatocyte cell death and liver damage in these settings.
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Affiliation(s)
- Mallikarjuna R. Metukuri
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Donna Beer-Stolz
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Rajaie A. Namas
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Rajeev Dhupar
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Andres Torres
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Patricia A. Loughran
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Bahiyyah S. Jefferson
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Allan Tsung
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Timothy R. Billiar
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Yoram Vodovotz
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Ruben Zamora
- Departments of Surgery and Medicine and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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Prabhakaran K, Chapman GD, Gunasekar PG. BNIP3 up-regulation and mitochondrial dysfunction in manganese-induced neurotoxicity. Neurotoxicology 2009; 30:414-22. [PMID: 19442826 DOI: 10.1016/j.neuro.2009.02.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Revised: 02/11/2009] [Accepted: 02/13/2009] [Indexed: 12/18/2022]
Abstract
The central nervous system (CNS) appears to be the critical target of manganese (Mn), and neurotoxicity has been the focus of most of the health effects of manganese. In brain, the mechanism underlying the Mn-induced cell death is not clear. We have previously demonstrated that NFkappabeta induction and the activation of nitric oxide synthase through reactive oxygen species (ROS) represent a proximate mechanism for Mn-induced neurotoxicity. In this study, an immortalized dopaminergic cells were used to characterize the cell death signaling cascade activated by manganese. Exposure to Mn resulted in a time and concentration-related loss of cell viability as observed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and live/dead cell assay. Mn increased BNIP3 expression within 3h and continued to increase up to 24h exposure followed by a concentration-related apoptotic death as determined by TUNEL. Further, Mn treatment resulted in accumulation of reactive oxygen species and mitochondrial dysfunction with loss of mitochondrial membrane potential and release of cytochrome c. Antioxidants significantly reduced Mn-induced BNIP3 expression and attenuated cell death, demonstrating the role of oxidative stress in BNIP3 induction. Blocking BNIP3 up-regulation with a transcription or a translational inhibitor reduced the response to manganese. Cell death by manganese was reduced in the presence of CsA (PT pore inhibitor). In addition, knockdown of BNIP3 by small interfering RNA (siRNA) improved mitochondrial recovery and reduced neuronal cell loss suggesting that constitutive expression of BNIP3 plays a role in Mn-induced neurotoxicity by regulating mitochondrial functions. These findings indicate a potential detrimental role of BNIP3 in manganese-induced neuronal cell death.
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Affiliation(s)
- Krishnan Prabhakaran
- Naval Health Research Center Detachment, Environmental Health Effects Laboratory, Wright-Patterson Air Force Base, 2729 R Street, Area B, Building 837, Dayton, OH 45433, USA
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Shi H. Hypoxia inducible factor 1 as a therapeutic target in ischemic stroke. Curr Med Chem 2009; 16:4593-600. [PMID: 19903149 PMCID: PMC2819104 DOI: 10.2174/092986709789760779] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2009] [Accepted: 11/13/2009] [Indexed: 11/22/2022]
Abstract
In stroke research, a significant focus is to develop therapeutic strategies that prevent neuronal death and improve recovery. Yet, few successful therapeutic strategies have emerged. Hypoxia-inducible factor 1 (HIF-1) is a key regulator in hypoxia. It has been suggested to be an important player in neurological outcomes following ischemic stroke due to the functions of its downstream genes. These include genes that promote glucose metabolism, angiogenesis, erythropoiesis, and cell survival. Many lines of evidence have shown that HIF-1 is induced in ischemic brains. Importantly, it seems that HIF-1 is primarily induced in the salvageable tissue of an ischemic brain, penumbra. However, the effect of HIF-1 on neuronal tissue injuries is still debatable based on evidence from in vitro and preclinical studies. Furthermore, it is of importance to understand the mechanism of HIF-1 degradation after its induction in ischemic brain. This review provides a present understanding of the mechanism of HIF-1 induction in ischemic neurons and the potential effect of HIF-1 on ischemic brain tissue. The author also elaborates on potential therapeutic approaches through understanding of the induction mechanism and of the potential role of HIF-1 in ischemic stroke.
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Affiliation(s)
- Honglian Shi
- Department of Pharmacology and Toxicology, University of Kansas, School of Pharmacy, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS 66045, USA.
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Hao YX, Zhong H, Yu PW, Zhang C, Zeng DZ, Shi Y, Tang B. Effects of HIF-1alpha on human gastric cancer cell apoptosis at different CO(2) pressures. Clin Exp Med 2008; 9:139-47. [PMID: 19048182 DOI: 10.1007/s10238-008-0023-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Accepted: 11/10/2008] [Indexed: 01/06/2023]
Abstract
The effects and potential molecular mechanisms underlying carbon dioxide (CO(2)) pneumoperitoneum on gastric cancer cell apoptosis are not fully understood. In this study, we assessed the effects of CO(2) pneumoperitoneum on the apoptosis of MKN-45 gastric cancer cells. Additionally, we investigated the role of HIF-1alpha in CO(2) pneumoperitoneum-induced apoptosis of gastric cancer cells. MKN-45 cells were cultured in CO(2) or air pneumoperitoneum at 0, 12 and 15 mmHg pressures for 4 h. We observed a change in cells morphology and increasing apoptotic ratios in MKN-45 cells when they were put into a 15 mmHg CO(2) pneumoperitoneum environment. However, there was no significant difference between the 0, 12 mmHg CO(2) pneumoperitoneum and the control groups. Exposure to 15 mmHg CO(2) pneumoperitoneum significantly enhanced the expression levels of HIF-1alpha and Bax, while it attenuated Bcl-2 expression levels. When we inhibited HIF-1alpha by small interfering RNA (siRNA), we found that the apoptotic ratio of MKN-45 cells decreased in 15 mmHg CO(2) pneumoperitoneum. This treatment markedly elevated Bcl-2 levels and decreased Bax expression. These data suggest that CO(2) pneumoperitoneum may accelerate the apoptosis of MKN-45 cells at higher pressures. HIF-1alpha is a crucial factor that affects gastric cancer cell apoptosis by downregulating the Bcl-2/Bax ratio.
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Affiliation(s)
- Ying-Xue Hao
- Department of General Surgery and Center of Minimal Invasive Gastrointestinal Surgery, Southwest Hospital, Third Military Medical University, 400038 Chongqing, People's Republic of China
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Gomez-Niño A, Agapito MT, Obeso A, Gonzalez C. Effects of mitochondrial poisons on glutathione redox potential and carotid body chemoreceptor activity. Respir Physiol Neurobiol 2008; 165:104-11. [PMID: 18996500 DOI: 10.1016/j.resp.2008.10.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 10/24/2008] [Accepted: 10/28/2008] [Indexed: 12/22/2022]
Abstract
Low oxygen sensing in chemoreceptor cells involves the inhibition of specific plasma membrane K(+) channels, suggesting that mitochondria-derived reactive oxygen species (ROS) link hypoxia to K(+) channel inhibition, subsequent cell depolarization and activation of neurotransmitter release. We have used several mitochondrial poisons, alone and in combination with the antioxidant N-acetylcysteine (NAC), and quantify their capacity to alter GSH/GSSG levels and glutathione redox potential (E(GSH)) in rat diaphragm. Selected concentrations of mitochondrial poisons with or without NAC were tested for their capacity to activate neurotransmitter release in chemoreceptor cells and to alter ATP levels in intact rat carotid body (CB). We found that rotenone (1 microM), antimycin A (0.2 microg/ml) and sodium azide (5mM) decreased E(GSH); NAC restored E(GSH) to control values. At those concentrations mitochondrial poisons activated neurotransmitter release from CB chemoreceptor cells and decreased CB ATP levels, NAC being ineffective to modify these responses. Additional experiments with 3-nitroprionate (5mM), lower concentrations of rotenone and dinitrophenol revealed variable relationships between E(GSH) and chemoreceptor cell neurotransmitter release responses and ATP levels. These findings indicate a lack of correlation between mitochondrial-generated modifications of E(GSH) and chemoreceptor cells activity. This lack of correlation renders unlikely that alteration of mitochondrial production of ROS is the physiological pathway chemoreceptor cells use to signal hypoxia.
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Affiliation(s)
- A Gomez-Niño
- Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Facultad de Medicina, Instituto de Biología y Genética Molecular, Valladolid, Spain
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Malhotra R, Tyson DW, Rosevear HM, Brosius FC. Hypoxia-inducible factor-1alpha is a critical mediator of hypoxia induced apoptosis in cardiac H9c2 and kidney epithelial HK-2 cells. BMC Cardiovasc Disord 2008; 8:9. [PMID: 18447926 PMCID: PMC2387135 DOI: 10.1186/1471-2261-8-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 04/30/2008] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Hypoxia inducible factor-1 (HIF-1) is a transcription factor that functions to maintain cellular homeostasis in response to hypoxia. There is evidence that HIF-1 can also trigger apoptosis, possibly when cellular responses are inadequate to meet energy demands under hypoxic conditions. METHODS Cardiac derived H9c2 and renal tubular epithelial HK-2 cells expressing either the wild type oxygen regulated subunit of HIF-1 (pcDNA3-Hif-1alpha) or a dominant negative version that lacked both DNA binding and transactivation domains (pcDNA3-DN-Hif-1alpha), were maintained in culture and exposed to hypoxia. An RNA interference approach was also employed to selectively knockdown expression of Hif-1alpha. Apoptosis was analyzed in both H9c2 and HK-2 cells by Hoechst and TUNEL staining, caspase 3 activity assays and activation of pro-apoptotic Bcl2 family member Bax. RESULTS Overexpression of pcDNA3-DN-Hif-1alpha led to a significant reduction in hypoxia -induced apoptosis (17 +/- 2%, P < 0.01) in H9c2 cells compared to both control-transfected and wild type Hif-1alpha transfected cells. Moreover, selective ablation of HIF-1alpha protein expression by RNA interference in H9c2 cells led to 55% reduction of caspase 3 activity and 46% reduction in the number of apoptotic cells as determined by Hoechst 33258 staining, after hypoxia. Finally, upregulation of the pro-apoptotic protein, Bax, was found in H9c2 cells overexpressing full-length pcDNA3-HA-HIF-1alpha exposed to hypoxia. In HK-2 cells overexpression of wild-type Hif-1alpha led to a two-fold increase in Hif-1alpha levels during hypoxia. This resulted in a 3.4-fold increase in apoptotic cells and a concomitant increase in caspase 3 activity during hypoxia when compared to vector transfected control cells. HIF-1alpha also induced upregulation of Bax in HK-2 cells. In addition, introduction of dominant negative Hif-1alpha constructs in both H9c2 and HK-2 -cells led to decreased active Bax expression. CONCLUSION These data demonstrate that HIF-1alpha is an important component of the apoptotic signaling machinery in the two cell types.
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Affiliation(s)
- Ricky Malhotra
- Department of Internal Medicine/Nephrology, University of Michigan Medical Center, Ann Arbor, MI-48109-0676, USA
| | - David W Tyson
- Department of Internal Medicine/Nephrology, University of Michigan Medical Center, Ann Arbor, MI-48109-0676, USA
| | - Henry M Rosevear
- Department of Internal Medicine/Nephrology, University of Michigan Medical Center, Ann Arbor, MI-48109-0676, USA
| | - Frank C Brosius
- Department of Internal Medicine/Nephrology, University of Michigan Medical Center, Ann Arbor, MI-48109-0676, USA
- Department of Molecular and Integrative Physiology University of Michigan Medical Center, Ann Arbor, MI-48109-0676, USA
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Sen CK, Roy S. Redox signals in wound healing. Biochim Biophys Acta Gen Subj 2008; 1780:1348-61. [PMID: 18249195 DOI: 10.1016/j.bbagen.2008.01.006] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Revised: 12/31/2007] [Accepted: 01/14/2008] [Indexed: 12/19/2022]
Abstract
Physical trauma represents one of the most primitive challenges that threatened survival. Healing a problem wound requires a multi-faceted comprehensive approach. First and foremost, the wound environment will have to be made receptive to therapies. Second, the appropriate therapeutic regimen needs to be identified and provided while managing systemic limitations that could secondarily limit the healing response. Unfortunately, most current solutions seem to aim at designing therapeutic regimen with little or no consideration of the specific details of the wound environment and systemic limitations. One factor that is centrally important in making the wound environment receptive is correction of wound hypoxia. Recent work have identified that oxygen is not only required to disinfect wounds and fuel healing but that oxygen-dependent redox-sensitive signaling processes represent an integral component of the healing cascade. Over a decade ago, it was proposed that in biological systems oxidants are not necessarily always the triggers for oxidative damage and that oxidants such as H2O2 could actually serve as signaling messengers and drive several aspects of cellular signaling. Today, that concept is much more developed and mature. Evidence supporting the role of oxidants such as H2O2 as signaling messenger is compelling. A complete understanding of the continuum between the classical and emergent roles of oxygen requires a thorough consideration of current concepts in redox biology. The objective of this review is to describe our current understanding of how redox-sensitive processes may drive dermal tissue repair.
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Affiliation(s)
- Chandan K Sen
- Comprehensive Wound Center, Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
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Lombaert N, Lison D, Van Hummelen P, Kirsch-Volders M. In vitro expression of hard metal dust (WC-Co)--responsive genes in human peripheral blood mononucleated cells. Toxicol Appl Pharmacol 2007; 227:299-312. [PMID: 18078969 DOI: 10.1016/j.taap.2007.11.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2007] [Revised: 10/26/2007] [Accepted: 11/05/2007] [Indexed: 01/18/2023]
Abstract
Hard metals consist of tungsten carbide (WC) and metallic cobalt (Co) particles and are important industrial materials produced for their extreme hardness and high wear resistance properties. While occupational exposure to metallic Co alone is apparently not associated with an increased risk of cancer, the WC-Co particle mixture was shown to be carcinogenic in exposed workers. The in vitro mutagenic/apoptogenic potential of WC-Co in human peripheral blood mononucleated cells was previously demonstrated by us. This study aimed at obtaining a broader view of the pathways responsible for WC-Co induced carcinogenicity, and in particular genotoxicity and apoptosis. We analyzed the profile of gene expression induced in vitro by WC-Co versus control (24 h treatment) in human PBMC and monocytes using microarrays. The most significantly up-regulated pathways for WC-Co treated PBMC were apoptosis and stress/defense response; the most down-regulated was immune response. For WC-Co treated monocytes the most significantly up- and down-regulated pathways were nucleosome/chromatin assembly and immune response respectively. Quantitative RT-PCR data for a selection of the most strongly modulated genes (HMOX1, HSPA1A, HSPA1L, BNIP3, BNIP3L, ADORA2B, MT3, PLA2G7, TNFAIP6), and some additionally chosen apoptosis related genes (BCL2, BAX, FAS, FASL, TNFalpha), confirmed the microarray data after WC-Co exposure and demonstrated limited differences between the Co-containing compounds. Overall, this study provides the first analysis of gene expression induced by the WC-Co mixture showing a large profile of gene modulation and giving a preliminary indication for a hypoxia mimicking environment induced by WC-Co exposure.
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Affiliation(s)
- Noömi Lombaert
- Vrije Universiteit Brussel, Laboratorium voor Cellulaire Genetica, Pleinlaan 2, B-1050 Brussel, Belgium.
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Crankshaw DL, Goon DJW, Briggs JE, DeLong D, Kuskowski M, Patterson SE, Nagasawa HT. A novel paradigm for assessing efficacies of potential antidotes against neurotoxins in mice. Toxicol Lett 2007; 175:111-7. [PMID: 18024011 DOI: 10.1016/j.toxlet.2007.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2007] [Revised: 09/28/2007] [Accepted: 10/01/2007] [Indexed: 01/10/2023]
Abstract
Historically, antidotal potencies of cyanide antagonists were measured as increases in the experimental LD(50) for cyanide elicited by the antidotes. This required the use of high doses of cyanide following pre-treatment with the putative antidote. Since IACUC guidelines at our institutions strongly discourage LD(50) determinations: we developed a new test paradigm that allowed for maximal survival of cyanide-treated animals with greatly reduced numbers of animals. Symptoms of cyanide toxicity include disruption of neuromuscular coordination, i.e., the righting reflex. Therefore, to establish a dose-response curve, the times required for recovery of this righting reflex with increasing doses of cyanide were measured. A cyanide dose that disrupted this righting reflex for approximately 1h with minimal deaths was then selected. Using this paradigm, the current cyanide antidotes, viz., nitrite plus thiosulfate and hydroxocobalamin, as well as some potential cyanide antidotes that we developed, were evaluated pre- and post-cyanide. This allowed, for the first time, the assessment of the post-cyanide effectiveness of the current antidotes against cyanide poisoning in a live animal. In addition, some prototype compounds were found to exhibit antidotal efficacy not only when injected i.p. following cyanide, but also when administered orally 30 min before cyanide. Pre-cyanide oral efficacy suggests that such compounds have the potential of being administered prophylactically before exposure to cyanide. This new test paradigm was found to be a powerful tool for assessing the efficacies of some novel antidotes against cyanide and should be equally applicable for evaluating putative antidotes for other neurotoxins.
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Affiliation(s)
- Daune L Crankshaw
- Center for Drug Design, Academic Health Center, University of Minnesota, MN, United States.
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Prabhakaran K, Li L, Zhang L, Borowitz JL, Isom GE. Upregulation of BNIP3 and translocation to mitochondria mediates cyanide-induced apoptosis in cortical cells. Neuroscience 2007; 150:159-67. [PMID: 17980495 DOI: 10.1016/j.neuroscience.2007.07.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 06/22/2007] [Accepted: 07/24/2007] [Indexed: 02/04/2023]
Abstract
Bcl-2/adenovirus E1B 19-kDa-interacting protein 3 (BNIP3), a Bcl-2 homology domain 3 (BH3) domain only protein, has been identified as a mitochondrial mediator of hypoxia-induced cell death. Since cyanide produces histotoxic anoxia (chemical hypoxia), the present study was undertaken in primary rat cortical cells to determine involvement of the BNIP3 signaling pathway in cyanide-induced death. Over a 20 h exposure KCN increased BNIP3 expression, followed by a concentration-related apoptotic death. To determine if BNIP3 plays a role in the cell death, expression was either increased with BNIP3 cDNA (BNIP3+) or knocked down with small interfering RNA (RNAi). In BNIP3+ cells, cyanide-induced apoptotic death was markedly enhanced and preceded by reduction of mitochondrial membrane potential (delta psim), release of cytochrome c from mitochondria and elevated caspase 3 and 7 activity. Pretreatment with the pan-caspase inhibitor N-benzyloxycarbonyl-Ala-Asp-fluoromethyl ketone (zVAD-fmk) suppressed BNIP3+-mediated cell death, thus confirming a caspase-dependent apoptosis. On the other hand, BNIP3 knockdown by RNAi or antagonism of BNIP3 by a transmembrane-deleted dominant-negative mutant (BNIP3 delta TM) markedly reduced cell death. Immunohistochemical imaging showed that cyanide stimulated translocation of BNIP3 from cytosol to mitochondria and displacement studies with BNIP3 delta TM showed that integration of BNIP3 into the mitochondrial outer membrane was necessary for the cell death. In BNIP3+ cells, cyclosporin-A, an inhibitor of mitochondrial pore transition, blocked the cyanide-induced reduction of delta psim and decreased the apoptotic death. These results demonstrate in cortical cells that cyanide induces a rapid upregulation of BNIP3 expression, followed by translocation to the mitochondrial outer membrane to reduce delta psim. This was followed by mitochondrial release of cytochrome c to execute a caspase-dependent cell death.
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Affiliation(s)
- K Prabhakaran
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN 47907-1333, USA
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