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The Dual Role of Oxidants in Male (In)fertility: Every ROSe Has a Thorn. Int J Mol Sci 2023; 24:ijms24054994. [PMID: 36902424 PMCID: PMC10002566 DOI: 10.3390/ijms24054994] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 02/22/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023] Open
Abstract
The role of oxidative stress (OS) in male infertility as a primary etiology and/or concomitant cause in other situations, such as inflammation, varicocele and gonadotoxin effects, is well documented. While reactive oxygen species (ROS) are implicated in many important roles, from spermatogenesis to fertilization, epigenetic mechanisms which are transmissible to offspring have also recently been described. The present review is focused on the dual aspects of ROS, which are regulated by a delicate equilibrium with antioxidants due to the special frailty of spermatozoa, in continuum from physiological condition to OS. When the ROS production is excessive, OS ensues and is amplified by a chain of events leading to damage of lipids, proteins and DNA, ultimately causing infertility and/or precocious pregnancy termination. After a description of positive ROS actions and of vulnerability of spermatozoa due to specific maturative and structural characteristics, we linger on the total antioxidant capacity (TAC) of seminal plasma, which is a measure of non-enzymatic non-proteic antioxidants, due to its importance as a biomarker of the redox status of semen; the therapeutic implications of these mechanism play a key role in the personalized approach to male infertility.
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2
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Park YJ, Pang WK, Pang MG. Integration of omics studies indicates that species-dependent molecular mechanisms govern male fertility. J Anim Sci Biotechnol 2023; 14:28. [PMID: 36859388 PMCID: PMC9979430 DOI: 10.1186/s40104-023-00836-1] [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: 08/03/2022] [Accepted: 01/10/2023] [Indexed: 03/03/2023] Open
Abstract
BACKGROUND Comparative and comprehensive omics studies have recently been conducted to provide a comprehensive understanding of the biological mechanisms underlying infertility. However, because these huge omics datasets often contain irrelevant information, editing strategies for summarizing and filtering the data are necessary prerequisite steps for identifying biomarkers of male fertility. Here, we attempted to integrate omics data from spermatozoa with normal and below-normal fertility from boars and bulls, including transcriptomic, proteomic, and metabolomic data. Pathway enrichment analysis was conducted and visualized using g:Profiler, Cytoscape, EnrichmentMap, and AutoAnnotation to determine fertility-related biological functions according to species. RESULTS In particular, gamete production and protein biogenesis-associated pathways were enriched in bull spermatozoa with below-normal fertility, whereas mitochondrial-associated metabolic pathways were enriched in boar spermatozoa with normal fertility. These results indicate that below-normal fertility may be determined by aberrant regulation of protein synthesis during spermatogenesis, and the modulation of reactive oxygen species generation to maintain capacitation and the acrosome reaction governs boar sperm fertility. CONCLUSION Overall, this approach demonstrated that distinct molecular pathways drive sperm fertility in mammals in a species-dependent manner. Moreover, we anticipate that searching for species-specific signaling pathways may aid in the discovery of fertility-related biomarkers within large omics datasets.
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Affiliation(s)
- Yoo-Jin Park
- grid.254224.70000 0001 0789 9563Department of Animal Science & Technology and BET Research Institute, Chung-Ang University, Anseong, Gyeonggi-do, 17546 Republic of Korea
| | - Won-Ki Pang
- grid.254224.70000 0001 0789 9563Department of Animal Science & Technology and BET Research Institute, Chung-Ang University, Anseong, Gyeonggi-do, 17546 Republic of Korea
| | - Myung-Geol Pang
- Department of Animal Science & Technology and BET Research Institute, Chung-Ang University, Anseong, Gyeonggi-do, 17546, Republic of Korea.
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3
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Qamar AY, Naveed MI, Raza S, Fang X, Roy PK, Bang S, Tanga BM, Saadeldin IM, Lee S, Cho J. Role of antioxidants in fertility preservation of sperm - A narrative review. Anim Biosci 2023; 36:385-403. [PMID: 36397685 PMCID: PMC9996255 DOI: 10.5713/ab.22.0325] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 11/07/2022] [Indexed: 11/15/2022] Open
Abstract
Male fertility is affected by multiple endogenous stressors, including reactive oxygen species (ROS), which greatly deteriorate the fertility. However, physiological levels of ROS are required by sperm for the proper accomplishment of different cellular functions including proliferation, maturation, capacitation, acrosomal reaction, and fertilization. Excessive ROS production creates an imbalance between ROS production and neutralization resulting in oxidative stress (OS). OS causes male infertility by impairing sperm functions including reduced motility, deoxyribonucleic acid damage, morphological defects, and enhanced apoptosis. Several in-vivo and in-vitro studies have reported improvement in quality-related parameters of sperm following the use of different natural and synthetic antioxidants. In this review, we focus on the causes of OS, ROS production sources, mechanisms responsible for sperm damage, and the role of antioxidants in preserving sperm fertility.
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Affiliation(s)
- Ahmad Yar Qamar
- College of Veterinary and Animal Sciences, Jhang 35200, Sub-campus of University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
| | - Muhammad Ilyas Naveed
- College of Veterinary and Animal Sciences, Jhang 35200, Sub-campus of University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
| | - Sanan Raza
- College of Veterinary and Animal Sciences, Jhang 35200, Sub-campus of University of Veterinary and Animal Sciences, Lahore 54000, Pakistan
| | - Xun Fang
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Pantu Kumar Roy
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Seonggyu Bang
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Bereket Molla Tanga
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Islam M Saadeldin
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Sanghoon Lee
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea
| | - Jongki Cho
- Laboratory of Theriogenology, College of Veterinary Medicine, Chungnam National University, Daejeon 34134, Korea.,Daejeon Wildlife Rescue Center, Chungnam National University, Daejeon 34134, Korea
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4
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Ávila C, Vinay JI, Arese M, Saso L, Rodrigo R. Antioxidant Intervention against Male Infertility: Time to Design Novel Strategies. Biomedicines 2022; 10:biomedicines10123058. [PMID: 36551814 PMCID: PMC9775742 DOI: 10.3390/biomedicines10123058] [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: 09/30/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/29/2022] Open
Abstract
Infertility is a highly prevalent condition, affecting 9-20% of couples worldwide. Among the identifiable causes, the male factor stands out in about half of infertile couples, representing a growing problem. Accordingly, there has been a decline in both global fertility rates and sperm counts in recent years. Remarkably, nearly 80% of cases of male infertility (MI) have no clinically identifiable aetiology. Among the mechanisms likely plausible to account for idiopathic cases, oxidative stress (OS) has currently been increasingly recognized as a key factor in MI, through phenomena such as mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation and finally, sperm apoptosis. In addition, elevated reactive oxygen species (ROS) levels in semen are associated with worse reproductive outcomes. However, despite an increasing understanding on the role of OS in the pathophysiology of MI, therapeutic interventions based on antioxidants have not yet provided a consistent benefit for MI, and there is currently no clear consensus on the optimal antioxidant constituents or regimen. Therefore, there is currently no applicable antioxidant treatment against this problem. This review presents an approach aimed at designing an antioxidant strategy based on the particular biological properties of sperm and their relationships with OS.
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Affiliation(s)
- Cristóbal Ávila
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380000, Chile
| | - José Ignacio Vinay
- Urology Department, University of Chile Clinical Hospital, Santiago 8380000, Chile
- Andrology Unit, Shady Grove Fertility, Santiago 7650672, Chile
| | - Marzia Arese
- Department of Biochemical Sciences “A. Rossi-Fanelli”, Sapienza University of Rome, 00185 Rome, Italy
| | - Luciano Saso
- Department of Physiology and Pharmacology “Vittorio Erspamer”, Faculty of Pharmacy and Medicine, Sapienza University, 00185 Rome, Italy
| | - Ramón Rodrigo
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380000, Chile
- Correspondence: ; Tel.: +56-229-786-126
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5
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Pereira SC, Moreira MV, Silva BM, Oliveira PF, Alves MG. Roles of Oxidative Stress in the Male Reproductive System: Potential of Antioxidant Supplementation for Infertility Treatment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1391:259-274. [PMID: 36472827 DOI: 10.1007/978-3-031-12966-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The decline of fertility in modern society is a serious worldwide concern, and the reasons behind it are complex and difficult to unveil. The fact that a big percentage of infertility cases remain diagnosed as idiopathic, turn the strategies to treat such conditions very limited. Nevertheless, one must agree that keeping the oxidative balance of the reproductive tissues should be one of the first lines of treatment for infertile patients. As reported, 30-80% of male infertile individuals present high levels of prooxidant species in the seminal fluid. Thus, antioxidant therapies, which consist of dietary supplementation therapy with one or more antioxidant compound, remain the first step in the treatment of male infertility. Nevertheless, the efficacy of such therapies is variable between individuals. The most common prescribed antioxidants are carnitines and vitamins C and E, but recently phytochemical quercetin has emerged as a potential compound for the treatment of oxidative stress in the male reproductive system. Although there are several animals' evidence about the great potential of quercetin for the treatment of infertility, clinical trials on this subject remain scarce.
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Affiliation(s)
- Sara C Pereira
- Department of Anatomy, UMIB - Unit for Multidisciplinary Research in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
- ITR - Laboratory for Integrative and Translational Research in Population Health, University of Porto, Porto, Portugal
- QOPNA & LAQV, Department of Chemistry, University of Aveiro, Aveiro, Portugal
- Department of Pathology, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Mafalda V Moreira
- Department of Anatomy, UMIB - Unit for Multidisciplinary Research in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
| | - Branca M Silva
- Department of Medical Sciences, University of Beira Interior, Covilhã, Portugal
| | - Pedro F Oliveira
- QOPNA & LAQV, Department of Chemistry, University of Aveiro, Aveiro, Portugal
| | - Marco G Alves
- Department of Anatomy, UMIB - Unit for Multidisciplinary Research in Biomedicine, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal.
- ITR - Laboratory for Integrative and Translational Research in Population Health, University of Porto, Porto, Portugal.
- Biotechnology of Animal and Human Reproduction (TechnoSperm), Institute of Food and Agricultural Technology, University of Girona, Girona, Spain.
- Unit of Cell Biology, Department of Biology, Faculty of Sciences, University of Girona, Girona, Spain.
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6
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Reactive Oxygen Species in the Reproductive System: Sources and Physiological Roles. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1358:9-40. [DOI: 10.1007/978-3-030-89340-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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7
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Sackheim AM, Villalba N, Sancho M, Harraz OF, Bonev AD, D’Alessandro A, Nemkov T, Nelson MT, Freeman K. Traumatic Brain Injury Impairs Systemic Vascular Function Through Disruption of Inward-Rectifier Potassium Channels. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab018. [PMID: 34568829 PMCID: PMC8462507 DOI: 10.1093/function/zqab018] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Trauma can lead to widespread vascular dysfunction, but the underlying mechanisms remain largely unknown. Inward-rectifier potassium channels (Kir2.1) play a critical role in the dynamic regulation of regional perfusion and blood flow. Kir2.1 channel activity requires phosphatidylinositol 4,5-bisphosphate (PIP2), a membrane phospholipid that is degraded by phospholipase A2 (PLA2) in conditions of oxidative stress or inflammation. We hypothesized that PLA2-induced depletion of PIP2 after trauma impairs Kir2.1 channel function. A fluid percussion injury model of traumatic brain injury (TBI) in rats was used to study mesenteric resistance arteries 24 hours after injury. The functional responses of intact arteries were assessed using pressure myography. We analyzed circulating PLA2, hydrogen peroxide (H2O2), and metabolites to identify alterations in signaling pathways associated with PIP2 in TBI. Electrophysiology analysis of freshly-isolated endothelial and smooth muscle cells revealed a significant reduction of Ba2+-sensitive Kir2.1 currents after TBI. Additionally, dilations to elevated extracellular potassium and BaCl2- or ML 133-induced constrictions in pressurized arteries were significantly decreased following TBI, consistent with an impairment of Kir2.1 channel function. The addition of a PIP2 analog to the patch pipette successfully rescued endothelial Kir2.1 currents after TBI. Both H2O2 and PLA2 activity were increased after injury. Metabolomics analysis demonstrated altered lipid metabolism signaling pathways, including increased arachidonic acid, and fatty acid mobilization after TBI. Our findings support a model in which increased H2O2-induced PLA2 activity after trauma hydrolyzes endothelial PIP2, resulting in impaired Kir2.1 channel function.
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Affiliation(s)
- Adrian M Sackheim
- Department of Surgery, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Nuria Villalba
- Department of Surgery, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Maria Sancho
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Osama F Harraz
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Adrian D Bonev
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Angelo D’Alessandro
- Department of Surgery, University of Colorado School of Medicine, Aurora, CO, USA
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA
- Division of Cardiovascular Sciences, University of Manchester, Manchester, UK
| | - Kalev Freeman
- Department of Surgery, University of Vermont Larner College of Medicine, Burlington, VT, USA
- Department of Pharmacology, University of Vermont Larner College of Medicine, Burlington, VT, USA
- Address correspondence to K.F. (e-mail: )
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8
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Park YJ, Pang MG. Mitochondrial Functionality in Male Fertility: From Spermatogenesis to Fertilization. Antioxidants (Basel) 2021; 10:antiox10010098. [PMID: 33445610 PMCID: PMC7826524 DOI: 10.3390/antiox10010098] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are structurally and functionally distinct organelles that produce adenosine triphosphate (ATP) through oxidative phosphorylation (OXPHOS), to provide energy to spermatozoa. They can also produce reactive oxidation species (ROS). While a moderate concentration of ROS is critical for tyrosine phosphorylation in cholesterol efflux, sperm–egg interaction, and fertilization, excessive ROS generation is associated with male infertility. Moreover, mitochondria participate in diverse processes ranging from spermatogenesis to fertilization to regulate male fertility. This review aimed to summarize the roles of mitochondria in male fertility depending on the sperm developmental stage (from male reproductive tract to female reproductive tract). Moreover, mitochondria are also involved in testosterone production, regulation of proton secretion into the lumen to maintain an acidic condition in the epididymis, and sperm DNA condensation during epididymal maturation. We also established the new signaling pathway using previous proteomic data associated with male fertility, to understand the overall role of mitochondria in male fertility. The pathway revealed that male infertility is associated with a loss of mitochondrial proteins in spermatozoa, which induces low sperm motility, reduces OXPHOS activity, and results in male infertility.
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9
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Baskaran S, Finelli R, Agarwal A, Henkel R. Reactive oxygen species in male reproduction: A boon or a bane? Andrologia 2020; 53:e13577. [PMID: 32271474 DOI: 10.1111/and.13577] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 03/03/2020] [Indexed: 12/12/2022] Open
Abstract
Reactive oxygen species (ROS) are free radicals derived from oxygen during normal cellular metabolism. ROS play a crucial role in the physiological processes and signalling pathways associated with male fertility. At physiological concentrations, ROS act as molecular mediators of signal transduction pathways involved in the regulation of the hypothalamic-pituitary-gonadal axis, spermatogenesis and steroidogenesis. They also trigger the morphological changes required for sperm maturation, such as DNA compaction and flagellar modification. Furthermore, ROS modulate crucial processes involved in the attainment of sperm fertilising ability such as capacitation, hyperactivation, acrosome reaction and sperm-oocyte fusion. Conversely, oxidative stress prevails when the concentration of ROS overwhelms the body's antioxidant defence. Various endogenous and exogenous factors enhance the synthesis of ROS resulting in the disruption of structural and functional integrity of spermatozoa through the induction of apoptotic pathway and oxidation of molecules, such as lipids, proteins and DNA. Therefore, maintenance of a balanced redox state is critical for normal male reproductive functions. This article discusses the dual role of ROS in male reproduction, highlighting the physiological role as well as their pathological implications on male fertility.
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Affiliation(s)
- Saradha Baskaran
- American Center for Reproductive Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Renata Finelli
- American Center for Reproductive Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Ashok Agarwal
- American Center for Reproductive Medicine, Cleveland Clinic, Cleveland, OH, USA
| | - Ralf Henkel
- American Center for Reproductive Medicine, Cleveland Clinic, Cleveland, OH, USA.,Department of Medical Bioscience, University of the Western Cape, Bellville, South Africa
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10
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Kim JH, Kim KM, Jung MH, Jung JH, Kang KM, Jeong BK, Kim JP, Park JJ, Woo SH. Protective effects of alpha lipoic acid on radiation-induced salivary gland injury in rats. Oncotarget 2018; 7:29143-53. [PMID: 27072584 PMCID: PMC5045384 DOI: 10.18632/oncotarget.8661] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 03/16/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose Radiation therapy is a treatment for patients with head and neck (HN) cancer. However, radiation exposure to the HN often induces salivary gland (SG) dysfunction. We investigated the effect of α-lipoic acid (ALA) on radiation-induced SG injury in rats. Results ALA preserved acinoductal integrity and acinar cell secretary function following irradiation. These results are related to the mechanisms by which ALA inhibits oxidative stress by inhibiting gp91 mRNA and 8-OHdG expression and apoptosis of acinar cells and ductal cells by inactivating MAPKs in the early period and expression of inflammation-related factors including NF-κB, IκB-α, and TGF-β1 and fibrosis in late irradiated SG. ALA effects began in the acute phase and persisted for at least 56 days after irradiation. Materials and Methods Rats were assigned to followings: control, ALA only (100 mg/kg, i.p.), irradiated, and ALA administered 24 h and 30 min prior to irradiation. The neck area including the SG was evenly irradiated with 2 Gy per minute (total dose, 18 Gy) using a photon 6-MV linear accelerator. Rats were killed at 4, 7, 28, and 56 days after radiation. Conclusions Our results show that ALA could be used to ameliorate radiation-induced SG injury in patients with HN cancer.
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Affiliation(s)
- Jin Hyun Kim
- Biomedical Research Institute, Gyeongsang National University Hospital, Jinju, Gyeongnam, Republic of Korea.,Institute of Health Science, Jinju, Gyeongnam, Republic of Korea
| | - Kyung Mi Kim
- Department of Otolaryngology, Jinju, Gyeongnam, Republic of Korea
| | - Myeong Hee Jung
- Biomedical Research Institute, Gyeongsang National University Hospital, Jinju, Gyeongnam, Republic of Korea
| | - Jung Hwa Jung
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Internal Medicine, Jinju, Gyeongnam, Republic of Korea
| | - Ki Mun Kang
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Gyeongnam, Republic of Korea
| | - Bae Kwon Jeong
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Radiation Oncology, Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju, Gyeongnam, Republic of Korea
| | - Jin Pyeong Kim
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Otolaryngology, Jinju, Gyeongnam, Republic of Korea
| | - Jung Je Park
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Otolaryngology, Jinju, Gyeongnam, Republic of Korea
| | - Seung Hoon Woo
- Institute of Health Science, Jinju, Gyeongnam, Republic of Korea.,Department of Otolaryngology, Jinju, Gyeongnam, Republic of Korea
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11
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Gao S, Li C, Chen L, Zhou X. Actions and mechanisms of reactive oxygen species and antioxidative system in semen. Mol Cell Toxicol 2017. [DOI: 10.1007/s13273-017-0015-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Bromfield EG, Mihalas BP, Dun MD, Aitken RJ, McLaughlin EA, Walters JL, Nixon B. Inhibition of arachidonate 15-lipoxygenase prevents 4-hydroxynonenal-induced protein damage in male germ cells†. Biol Reprod 2017; 96:598-609. [DOI: 10.1093/biolre/iox005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 01/30/2017] [Indexed: 12/20/2022] Open
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13
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Nandi AA, Wadhwani NS, Joshi SR. Altered metabolic homeostasis between vitamin D and long chain polyunsaturated fatty acids in preeclampsia. Med Hypotheses 2017; 100:31-36. [PMID: 28236844 DOI: 10.1016/j.mehy.2017.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Revised: 12/15/2016] [Accepted: 01/15/2017] [Indexed: 12/13/2022]
Abstract
Sub-optimal maternal nutrition may result in pregnancy complications like preeclampsia. Preeclampsia is known to be of placental origin and a major cause of maternal morbidity and mortality worldwide. Our earlier studies suggest that altered metabolism of folic acid, vitamin B12 and long chain polyunsaturated fatty acid (LCPUFAs) in the one carbon cycle increases homocysteine levels in preeclampsia. Recent reports indicate that vitamin D deficiency may also have a role in preeclampsia, although the mechanisms are unclear. A disturbed one carbon cycle can influence methylation patterns of various genes involved in placental development. Altered expression of cystathionine beta synthase (CBS) gene can result in hyperhomocystenemia. Higher homocysteine levels are known to increase reactive oxygen species (ROS) production which in turn leads to increased expression of phospholipase A2 (PLA2) and cyclooxygenase-2 (COX-2). Higher expression of PLA2 and COX-2 can influence the release of arachidonic acid (AA) from membrane phospholipid and result in increased conversion to thromboxane. Vitamin D [1,25(OH)2D3] is known to induce the CBS gene expression while it can suppress the oxidative stress-induced COX-2 up-regulation and thromboxane production. Based on this, we propose a novel hypothesis that a disturbed vitamin D and LCPUFA metabolism influence the regulation of the one carbon cycle which will trigger inflammation through oxidative stress in preeclampsia. This may lead to altered feto-placental growth and development in preeclampsia.
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Affiliation(s)
- Anindita A Nandi
- Department of Nutritional Medicine, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune 411043, India
| | - Nisha S Wadhwani
- Department of Nutritional Medicine, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune 411043, India
| | - Sadhana R Joshi
- Department of Nutritional Medicine, Interactive Research School for Health Affairs (IRSHA), Bharati Vidyapeeth Deemed University, Pune 411043, India.
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14
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Exposure to p, p'-DDE Induces Morphological Changes and Activation of the PKC α-p38-C/EBP β Pathway in Human Promyelocytic HL-60 Cells. BIOMED RESEARCH INTERNATIONAL 2016; 2016:1375606. [PMID: 27833915 PMCID: PMC5090076 DOI: 10.1155/2016/1375606] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/26/2016] [Accepted: 08/31/2016] [Indexed: 01/23/2023]
Abstract
Dichlorodiphenyldichloroethylene (p,p′-DDE), the most persistent metabolite of dichlorodiphenyltrichloroethane (DDT), is still present in the human population. Both are present in the bone marrow of patients with bone marrow disorders, but thus far there are no studies that assess the capability of p,p′-DDE to affect myeloid cells. The aim of this study was to determine the effect of p,p′-DDE on promyelocytic cell differentiation and intracellular pathways related to this event. p,p′-DDE induced morphological changes compatible with promyelocytic differentiation in a concentration-dependent manner. The p,p′-DDE effect on [Ca2+]i, C/EBPβ protein levels, PKCα and p38 activation, and the role of oxidative stress or PLA2 was assayed. Exposure to 1.9 μg/mL of p,p′-DDE increased [Ca2+]i, PKCα, p38, and C/EBPβ protein levels; the increase of nuclear C/EBPβ protein was dependent on p38. PKCα phosphorylation was dependent on PLA2 and p,p′-DDE-induced oxidative stress. p38 phosphorylation induced by p,p′-DDE was dependent on PLA2, PKC activation, and oxidative stress. These effects of p,p′-DDE at concentrations found in human bone marrow may induce alterations in immature myeloid cells and could affect their cellular homeostasis. In order to establish the risk from exposure to p,p′-DDE on the development of bone marrow disorders in humans, these effects deserve further study.
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15
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Du Plessis SS, Agarwal A, Halabi J, Tvrda E. Contemporary evidence on the physiological role of reactive oxygen species in human sperm function. J Assist Reprod Genet 2015; 32:509-20. [PMID: 25646893 PMCID: PMC4380893 DOI: 10.1007/s10815-014-0425-7] [Citation(s) in RCA: 151] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 12/29/2014] [Indexed: 01/01/2023] Open
Abstract
Reactive oxygen species (ROS) play an important role in male fertility. Overproduction of reactive oxygen species (ROS) has been associated with a variety of male fertility complications, including leukocytospermia, varicocele and idiopathic infertility. The subsequent oxidative insult to spermatozoa can manifest as insufficient energy metabolism, lipid peroxidation and DNA damage, leading to loss of motility and viability. However, various studies have demonstrated that physiological amounts of ROS play important roles in the processes of spermatozoa maturation, capacitation, hyperactivation and acrosome reaction. It is therefore crucial to define and understand the delicate oxidative balance in male reproductive cells and tissues for a better understanding of both positive as well as negative impact of ROS production on the fertilizing ability. This review will discuss the specific physiological roles, mechanisms of action and effects that ROS have on the acquisition of structural integrity and physiological activity of spermatozoa.
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Affiliation(s)
- Stefan S. Du Plessis
- />Center for Reproductive Medicine, Cleveland Clinic, 10681 Carnegie Avenue, Mail Code X-11, Cleveland, OH 44195 USA
- />Division of Medical Physiology, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa
| | - Ashok Agarwal
- />Center for Reproductive Medicine, Cleveland Clinic, 10681 Carnegie Avenue, Mail Code X-11, Cleveland, OH 44195 USA
| | - Jacques Halabi
- />Center for Reproductive Medicine, Cleveland Clinic, 10681 Carnegie Avenue, Mail Code X-11, Cleveland, OH 44195 USA
| | - Eva Tvrda
- />Center for Reproductive Medicine, Cleveland Clinic, 10681 Carnegie Avenue, Mail Code X-11, Cleveland, OH 44195 USA
- />Department of Animal Physiology, Slovak University of Agriculture, Nitra, Slovakia
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Beaulieu E, Ioffe J, Watson SN, Hermann PM, Wildering WC. Oxidative-stress induced increase in circulating fatty acids does not contribute to phospholipase A2-dependent appetitive long-term memory failure in the pond snail Lymnaea stagnalis. BMC Neurosci 2014; 15:56. [PMID: 24886155 PMCID: PMC4013061 DOI: 10.1186/1471-2202-15-56] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 04/23/2014] [Indexed: 11/23/2022] Open
Abstract
Background Reactive oxygen species (ROS) are essential for normal physiological functioning of the brain. However, uncompensated increase in ROS levels may results in oxidative stress. Phospholipase A2 (PLA2) is one of the key players activated by elevated ROS levels resulting in the hydrolysis of various products from the plasmamembrane such as peroxidized fatty acids. Free fatty acids (FFAs) and fatty acid metabolites are often implicated to the genesis of cognitive impairment. Previously we have shown that age-, and experimentally induced oxidative stress causes PLA2-dependent long-term memory (LTM) failure in an aversive operant conditioning model in Lymnaea stagnalis. In the present study, we investigate the effects of experimentally induced oxidative stress and the role of elevated levels of circulating FFAs on LTM function using a non-aversive appetitive classical conditioning paradigm. Results We show that intracoelomic injection of exogenous PLA2 or pro-oxidant induced PLA2 activation negatively affects LTM performance in our learning paradigm. In addition, we show that experimental induction of oxidative stress causes significant temporal changes in circulating FFA levels. Importantly, the time of training coincides with the peak of this change in lipid metabolism. However, intracoelomic injection with exogenous arachidonic acid, one of the main FFAs released by PLA2, does not affect LTM function. Moreover, sequestrating circulating FFAs with the aid of bovine serum albumin does not rescue pro-oxidant induced appetitive LTM failure. Conclusions Our data substantiates previous evidence linking lipid peroxidation and PLA2 activation to age- and oxidative stress-related cognitive impairment, neuronal dysfunction and disease. In addition however, our data indicate that lipid peroxidation induced increased levels of circulating (per)oxidized FFAs are not a factor in oxidative stress induced LTM impairment.
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Affiliation(s)
| | | | | | | | - Willem C Wildering
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
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17
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Lipton P. Lysosomal membrane permeabilization as a key player in brain ischemic cell death: a "lysosomocentric" hypothesis for ischemic brain damage. Transl Stroke Res 2013; 4:672-84. [PMID: 24323421 DOI: 10.1007/s12975-013-0301-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 12/13/2022]
Abstract
This is a speculative review of the role of the lysosome in ischemic cell death in the mammalian brain. In particular, it focuses on the role of the permeabilization of the lysosomal membrane to proteins (LMP) as a major mechanism of cell death in mild, but lethal, ischemic insults. The first section of the review outlines the evidence that this is the case, using the relatively few extant studies of mammalian brain. In the second section of the review, the mechanism by which an ischemic insult might lead to LMP is discussed. A metabolic sequence including NMDA receptor activation, activation of phospholipase A2 and production of free radicals, and also the activation of calpain are shown to be critical. The remainder of the section speculates on the actual agent(s) which may be causing the lysosomal membrane change, based on extensive literature references. There is currently no knowledge of the actual mechanism. The third section considers potential targets of the released lysosomal proteases and other proteins that might mediate the lethal effects of LMP, focusing largely on the mitochondria as the target. Again, this is speculative as the targets are not known. Finally, the fourth section addresses the level of importance that LMP has in the process of ischemic cell death and concludes that it may well play the major role during mild but lethal ischemic insults. This novel, so-called "lysosomocentric," hypothesis is briefly critiqued. The therapeutic potential of this conclusion is then discussed.
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Affiliation(s)
- Peter Lipton
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706, USA,
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18
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Hermann PM, Park D, Beaulieu E, Wildering WC. Evidence for inflammation-mediated memory dysfunction in gastropods: putative PLA2 and COX inhibitors abolish long-term memory failure induced by systemic immune challenges. BMC Neurosci 2013; 14:83. [PMID: 23915010 PMCID: PMC3750374 DOI: 10.1186/1471-2202-14-83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/02/2013] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Previous studies associate lipid peroxidation with long-term memory (LTM) failure in a gastropod model (Lymnaea stagnalis) of associative learning and memory. This process involves activation of Phospholipase A2 (PLA2), an enzyme mediating the release of fatty acids such as arachidonic acid that form the precursor for a variety of pro-inflammatory lipid metabolites. This study investigated the effect of biologically realistic challenges of L. stagnalis host defense response system on LTM function and potential involvement of PLA2, COX and LOX therein. RESULTS Systemic immune challenges by means of β-glucan laminarin injections induced elevated H2O2 release from L. stagnalis circulatory immune cells within 3 hrs of treatment. This effect dissipated within 24 hrs after treatment. Laminarin exposure has no direct effect on neuronal activity. Laminarin injections disrupted LTM formation if training followed within 1 hr after injection but had no behavioural impact if training started 24 hrs after treatment. Intermediate term memory was not affected by laminarin injection. Chemosensory and motor functions underpinning the feeding response involved in this learning model were not affected by laminarin injection. Laminarin's suppression of LTM induction was reversed by treatment with aristolochic acid, a PLA2 inhibitor, or indomethacin, a putative COX inhibitor, but not by treatment with nordihydro-guaiaretic acid, a putative LOX inhibitor. CONCLUSIONS A systemic immune challenge administered shortly before behavioural training impairs associative LTM function in our model that can be countered with putative inhibitors of PLA2 and COX, but not LOX. As such, this study establishes a mechanistic link between the state of activity of this gastropod's innate immune system and higher order nervous system function. Our findings underwrite the rapidly expanding view of neuroinflammatory processes as a fundamental, evolutionary conserved cause of cognitive and other nervous system disorders.
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Affiliation(s)
- Petra M Hermann
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, AB T2N 1N4, Canada
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19
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Dexamethasone inhibits the Nox-dependent ROS production via suppression of MKP-1-dependent MAPK pathways in activated microglia. BMC Neurosci 2011; 12:49. [PMID: 21615929 PMCID: PMC3121618 DOI: 10.1186/1471-2202-12-49] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Accepted: 05/26/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Nox-2 (also known as gp91phox), a subunit component of NADPH oxidases, generates reactive oxygen species (ROS). Nox-dependent ROS generation and nitric oxide (NO) release by microglia have been implicated in a variety of diseases in the central nervous system. Dexamethasone (Dex) has been shown to suppress the ROS production, NO release and inflammatory reaction of activated microglial cells. However, the underlying mechanisms remain unclear. RESULTS The present study showed that the increased ROS production and NO release in activated BV-2 microglial cells by LPS were associated with increased expression of Nox-2 and iNOS. Dex suppressed the upregulation of Nox-2 and iNOS, as well as the subsequent ROS production and NO synthesis in activated BV-2 cells. This inhibition caused by Dex appeared to be mediated by upregulation of MAPK phosphatase-1 (MKP-1), which antagonizes the activity of mitogen-activated protein kinases (MAPKs). Dex induced-suppression of Nox-2 and -upregulation of MKP-1 was also evident in the activated microglia from corpus callosum of postnatal rat brains. The overexpression of MKP-1 or inhibition of MAPKs (by specific inhibitors of JNK and p38 MAPKs), were found to downregulate the expression of Nox-2 and iNOS and thereby inhibit the synthesis of ROS and NO in activated BV-2 cells. Moreover, Dex was unable to suppress the LPS-induced synthesis of ROS and NO in BV-2 cells transfected with MKP-1 siRNA. On the other hand, knockdown of Nox-2 in BV-2 cells suppressed the LPS-induced ROS production and NO release. CONCLUSION In conclusion, it is suggested that downregulation of Nox-2 and overexpression of MKP-1 that regulate ROS and NO may form the potential therapeutic strategy for the treatment of neuroinflammation in neurodegenerative diseases.
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20
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Matsubara T, Tanaka N, Patterson AD, Cho JY, Krausz KW, Gonzalez FJ. Lithocholic acid disrupts phospholipid and sphingolipid homeostasis leading to cholestasis in mice. Hepatology 2011; 53:1282-93. [PMID: 21480330 PMCID: PMC3077083 DOI: 10.1002/hep.24193] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
UNLABELLED Lithocholic acid (LCA) is an endogenous compound associated with hepatic toxicity during cholestasis. LCA exposure in mice resulted in decreased serum lysophosphatidylcholine (LPC) and sphingomyelin levels due to elevated lysophosphatidylcholine acyltransferase (LPCAT) and sphingomyelin phosphodiesterase (SMPD) expression. Global metabolome analysis indicated significant decreases in serum palmitoyl-, stearoyl-, oleoyl-, and linoleoyl-LPC levels after LCA exposure. LCA treatment also resulted in decreased serum sphingomyelin levels and increased hepatic ceramide levels, and induction of LPCAT and SMPD messenger RNAs (mRNAs). Transforming growth factor-β (TGF-β) induced Lpcat2/4 and Smpd3 gene expression in primary hepatocytes and the induction was diminished by pretreatment with the SMAD3 inhibitor SIS3. Furthermore, alteration of the LPCs and Lpcat1/2/4 and Smpd3 expression was attenuated in LCA-treated farnesoid X receptor-null mice that are resistant to LCA-induced intrahepatic cholestasis. CONCLUSION This study revealed that LCA induced disruption of phospholipid/sphingolipid homeostasis through TGF-β signaling and that serum LPC is a biomarker for biliary injury.
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Affiliation(s)
- Tsutomu Matsubara
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Naoki Tanaka
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Andrew D. Patterson
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Joo-Youn Cho
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Kristopher W. Krausz
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892,Correspondence: Frank J. Gonzalez, Laboratory of Metabolism, National Cancer Institute, Building 37, Room 3106, Bethesda, MD 20892, Tel: 301–496–9067, Fax: 301–496–8419,
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21
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Park HS, Kim SR, Kim JO, Lee YC. The roles of phytochemicals in bronchial asthma. Molecules 2010; 15:6810-34. [PMID: 20924320 PMCID: PMC6259268 DOI: 10.3390/molecules15106810] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 09/16/2010] [Accepted: 09/30/2010] [Indexed: 02/02/2023] Open
Abstract
Despite gaps in our knowledge of how phytochemicals interfere with cellular functions, several natural plant products are utilized to prevent or treat a wide range of diseases. Identification of an agent with therapeutic potential requires multiple steps involving in vitro studies, efficacy and toxicity studies in animal models, and then human clinical trials. This review provides a brief introduction on natural products that may help to treat and/or prevent bronchial asthma and describes our current understanding of their molecular mechanisms based on various in vitro, in vivo, and clinical studies. We focus on the anti-inflammatory and anti-vascular actions of the plant products and other roles beyond the anti-oxidative effects.
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Affiliation(s)
- Hee Sun Park
- Department of Internal Medicine, Chungnam National University Medical School, Daejeon, Korea
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23
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Min W, Lin Y, Tang S, Yu L, Zhang H, Wan T, Luhn T, Fu H, Chen H. AIP1 recruits phosphatase PP2A to ASK1 in tumor necrosis factor-induced ASK1-JNK activation. Circ Res 2008; 102:840-8. [PMID: 18292600 DOI: 10.1161/circresaha.107.168153] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Previously we have shown that AIP1 (apoptosis signal-regulating kinase [ASK]1-interacting protein 1), a novel member of the Ras-GAP protein family, facilitates dephosphorylation of ASK1 at pSer967 and subsequently 14-3-3 release from ASK1, leading to enhanced ASK1-JNK signaling. However, the phosphatase(s) responsible for ASK1 dephosphorylation at pSer967 has not been identified. In the present study, we identified protein phosphatase (PP)2A as a potential phosphatase in vascular endothelial cells (ECs). Tumor necrosis factor (TNF)-induced dephosphorylation of ASK1 pSer967 in ECs was blocked by PP2A inhibitor okadaic acid. Overexpression of PP2A catalytic subunit induced dephosphorylation of ASK1 pSer967 and activation of c-Jun N-terminal kinase (JNK). In contrast, a catalytic inactive form of PP2A or PP2A small interfering RNA blunted TNF-induced dephosphorylation of ASK1 pSer967 and activation of JNK without effects on NF-kappaB activation. Whereas AIP1, via its C2 domain, binds to ASK1, PP2A binds to the GAP domain of AIP1. Endogenous AIP1-PP2A complex can be detected in the resting state, and TNF induces a complex formation of AIP1-PP2A with ASK1. Furthermore, TNF-induced association of PP2A with ASK1 was diminished in AIP1-knockdown ECs, suggesting a critical role of AIP1 in recruiting PP2A to ASK1. TNF-signaling molecules TRAF2 and RIP1, known to be in complex with AIP1 and activate AIP1 by phosphorylating AIP1 at Ser604, are critical for TNF-induced ASK1 dephosphorylation. Finally, PP2A and AIP1 cooperatively induce activation of ASK1-JNK signaling and EC apoptosis, as demonstrated by both overexpression and small interfering RNA knockdown approaches. Taken together, our data support a critical role of PP2A-AIP1 complex in TNF-induced activation of ASK1-JNK apoptotic signaling.
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Affiliation(s)
- Wang Min
- Vascular Biology and Therapeutics Program and Department of Pathology, Yale University School of Medicine, 10 Amistad St, New Haven, CT 06520, USA.
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24
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Li L, Frei B. Iron Chelation Inhibits NF-κB–Mediated Adhesion Molecule Expression by Inhibiting p22
phox
Protein Expression and NADPH Oxidase Activity. Arterioscler Thromb Vasc Biol 2006; 26:2638-43. [PMID: 16973969 DOI: 10.1161/01.atv.0000245820.34238.da] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Objective—
Excess iron may increase oxidative stress and play a role in vascular inflammation and atherosclerosis. Here we determined whether the iron chelator, desferrioxamine (DFO), ameliorates oxidative stress and cellular adhesion molecule expression in a murine model of local inflammation.
Methods and Results—
Dorsal air pouches were created in C57BL/6J mice by subcutaneous injection of air. DFO (100 mg/kg body weight) was injected into the air pouch once a day for two days followed immediately on the second day by lipopolysaccharide (LPS; 2.5 mg/kg body weight). The animals were euthanized 24 hours later for analysis of oxidative stress markers and adhesion molecules in air pouch tissue. LPS treatment enhanced protein levels of p22
phox
, a catalytic subunit of NADPH oxidase, and increased NADPH oxidase activity and levels of superoxide radicals and hydrogen peroxide. Furthermore, LPS activated NF-κB and increased expression of adhesion molecules. All of these inflammatory responses were strongly suppressed by DFO, but not iron-loaded DFO.
Conclusions—
Our data show that DFO inhibits LPS-induced, NADPH oxidase–mediated oxidative stress and, hence, NF-κB activation and adhesion molecule expression in a murine model of local inflammation. Iron chelation may be helpful in treating atherosclerotic vascular diseases by ameliorating oxidative stress and inflammation.
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Affiliation(s)
- Lixin Li
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331-6512, USA
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25
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Lyng FM, Maguire P, McClean B, Seymour C, Mothersill C. The involvement of calcium and MAP kinase signaling pathways in the production of radiation-induced bystander effects. Radiat Res 2006; 165:400-9. [PMID: 16579652 DOI: 10.1667/rr3527.1] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Much evidence now exists regarding radiation-induced bystander effects, but the mechanisms involved in the transduction of the signal are still unclear. The mitogen-activated protein kinase (MAPK) pathways have been linked to growth factor-mediated regulation of cellular events such as proliferation, senescence, differentiation and apoptosis. Activation of multiple MAPK pathways such as the ERK, JNK and p38 pathways have been shown to occur after exposure of cells to radiation and a variety of other toxic stresses. Previous studies have shown oxidative stress and calcium signaling to be important in radiation-induced bystander effects. The aim of the present study was to investigate MAPK signaling pathways in bystander cells exposed to irradiated cell conditioned medium (ICCM) and the role of oxidative metabolism and calcium signaling in the induction of bystander responses. Human keratinocytes (HPV-G cell line) were irradiated (0.005-5 Gy) using a cobalt-60 teletherapy unit. The medium was harvested 1 h postirradiation and transferred to recipient HPV-G cells. Phosphorylated forms of p38, JNK and ERK were studied by immunofluorescence 30 min-24 h after exposure to ICCM. Inhibitors of the ERK pathway (PD98059 and U0126), the JNK pathway (SP600125), and the p38 pathway (SB203580) were used to investigate whether bystander-induced cell death could be blocked. Cells were also incubated with ICCM in the presence of superoxide dismutase, catalase, EGTA, verapamil, nifedipine and thapsigargin to investigate whether bystander effects could be inhibited because of the known effects on calcium homeostasis. Activated forms of JNK and ERK proteins were observed after exposure to ICCM. Inhibition of the ERK pathway appeared to increase bystander-induced apoptosis, while inhibition of the JNK pathway appeared to decrease apoptosis. In addition, reactive oxygen species, such as superoxide and hydrogen peroxide, and calcium signaling were found to be important modulators of bystander responses. Further investigations of these signaling pathways may aid in the identification of novel therapeutic targets.
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Affiliation(s)
- F M Lyng
- Radiation and Environmental Science Centre, Focas Institute, Dublin Institute of Technology, Dublin 8, Ireland.
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26
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Colston JT, de la Rosa SD, Strader JR, Anderson MA, Freeman GL. H2O2 activates Nox4 through PLA2-dependent arachidonic acid production in adult cardiac fibroblasts. FEBS Lett 2005; 579:2533-40. [PMID: 15848200 DOI: 10.1016/j.febslet.2005.03.057] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Revised: 03/23/2005] [Accepted: 03/25/2005] [Indexed: 11/18/2022]
Abstract
Stimulated production of reactive oxygen species (ROS) by plasma membrane-associated nicotinamide adenine dinucleotide phosphate oxidases (Nox) in non-phagocytic cells regulates a number of biological processes including growth, vessel tone, and oxygen sensing. The purpose of this study was to investigate H(2)O(2)-stimulated ROS production in primary adult cardiac fibroblasts (CF). Results demonstrate that CF express an H(2)O(2)-inducible oxidant generating system that is inhibitable by diphenylene iodonium (DPI) and sensitive to antioxidants. In addition to H(2)O(2), generation of ROS was stimulated potently by 1-oleoyl-2-acetyl-sn-glycerol (OAG) and arachidonic acid (AA) in a protein kinase C-independent manner. Pretreatment with arachidonyl trifluoromethyl ketone was nearly as effective as DPI at reducing H(2)O(2)- and OAG-stimulated oxidant generation indicating a central role for phospholipase A(2) (PLA(2)) in this signaling pathway. Co-stimulation with H(2)O(2) and OAG did not increase ROS generation as compared to OAG alone suggesting both agonists signal through a shared, rate-limited enzymatic pathway involving PLA(2). Co-stimulation with H(2)O(2) and AA had additive effects indicating these two agonists stimulate oxidant production through a parallel activation pathway. Reverse transcriptase-coupled polymerase chain reaction and Western blotting demonstrate primary cardiac fibroblasts express transcripts and protein for Nox4, p22, p47, and p67 phox. Transfections with Nox4 small inhibitory ribonucleic acid oligonucleotides or p22 phox antisense oligonucleotides significantly downregulated stimulated Nox activity. Inhibitors of nitric oxide synthases were without effect. We conclude adult CF express Nox4/p22 phox-containing oxidant generating complex activated by H(2)O(2), OAG, and AA through a pathway that requires activation of PLA(2).
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Affiliation(s)
- James T Colston
- Janey Briscoe Center of Excellence in Cardiovascular Disease, Department of Medicine, Division of Cardiology, University of Texas Health Science Center, San Antonio, 78284, USA.
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Offer S, Eliraz A, Fink G, Stark AH, Madar Z. Interactions between nitric oxide and arachidonic acid in lung epithelial cells: possible roles for peroxynitrite and superoxide. Pharmacology 2004; 73:155-61. [PMID: 15572879 DOI: 10.1159/000082375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2004] [Accepted: 09/21/2004] [Indexed: 11/19/2022]
Abstract
This study investigated interactions between nitric oxide synthesis and phospholipase A2 (PLA2) activation in lung epithelial cells. Nitrite formation, inducible nitric oxide synthase expression, and [3H]arachidonic acid (AA) release were determined following treatment with: (1) the nitric oxide synthase inhibitors N(G)-nitro-L-arginine methyl esther (L-NAME) and aminoguanidine; (2) arachidonyl trifluoromethyl ketone (AACOCF3), a specific cytosolic PLA2 inhibitor; (3) S-morpholinosydnonimine (SIN-1), a nitric oxide donor which provokes peroxynitrite formation; (4) trolox, a free radical scavenger, and (5) the AA release agonists calcium ionophore, phorbol 12-myristate 13-acetate, and sodium vanadate. The results demonstrated that (1) L-NAME and aminoguanidine inhibited agonist-induced AA release by 40 and 65%, respectively; (2) AACOCF3 inhibited nitrite formation and inducible nitric oxide synthase expression in a dose-dependent manner; (3) SIN-1, together with AA release agonists, significantly increased the AA output, and (4) trolox counteracted the SIN-1 effects. Our results demonstrate cross talk between nitric oxide synthase and PLA(2) pathways, with a possible intermediary role for peroxynitrite and superoxide.
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Affiliation(s)
- Sarit Offer
- Institute of Biochemistry, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot, Israel
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Qin L, Liu Y, Wang T, Wei SJ, Block ML, Wilson B, Liu B, Hong JS. NADPH oxidase mediates lipopolysaccharide-induced neurotoxicity and proinflammatory gene expression in activated microglia. J Biol Chem 2003; 279:1415-21. [PMID: 14578353 DOI: 10.1074/jbc.m307657200] [Citation(s) in RCA: 467] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Parkinson's disease is characterized by the progressive degeneration of dopaminergic neurons in the substantia nigra. We have previously reported that lipopolysaccharide (LPS)-induced degeneration of dopaminergic neurons is mediated by the release of proinflammatory factors from activated microglia. Here, we report the pivotal role of NADPH oxidase in inflammation-mediated neurotoxicity, where the LPS-induced loss of nigral dopaminergic neurons in vivo was significantly less pronounced in NADPH oxidase-deficient (PHOX-/-) mice when compared with control (PHOX+/+) mice. Dopaminergic neurons in primary mensencephalic neuron-glia cultures from PHOX+/+ mice were significantly more sensitive to LPS-induced neurotoxicity in vitro when compared with PHOX-/- mice. Further, PHOX+/+ neuron-glia cultures chemically depleted of microglia failed to show dopaminergic neurotoxicity with the addition of LPS. Neuron-enriched cultures from both PHOX+/+ mice and PHOX-/- mice also failed to show any direct LPS-induced dopaminergic neurotoxicity. However, the addition of PHOX+/+ microglia to neuron-enriched cultures from either strain resulted in reinstatement of LPS-induced dopaminergic neurotoxicity, supporting the role of microglia as the primary source of NADPH oxidase-generated insult and neurotoxicity. Immunostaining for F4/80 in mensencephalic neuron-glia cultures revealed that PHOX-/- microglia failed to show activated morphology at 10 h, suggesting an important role of reactive oxygen species (ROS) generated from NADPH oxidase in the early activation of microglia. LPS also failed to elicit extracellular superoxide and produced low levels of intracellular ROS in microglia-enriched cultures from PHOX-/- mice. Gene expression and release of tumor necrosis factor alpha was much lower in PHOX-/- mice than in control PHOX+/+ mice. Together, these results demonstrate the dual neurotoxic functions of microglial NADPH oxidase: 1) the production of extracellular ROS that is toxic to dopamine neurons and 2) the amplification of proinflammatory gene expression and associated neurotoxicity.
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Affiliation(s)
- Liya Qin
- Neuropharmacology Section, Laboratory of Pharmacology and Chemistry, NIEHS, NIH, Research Triangle Park, NC 27709, USA
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Prabhu R, Balasubramanian KA. Effect of oxidants on small intestinal brush border membranes and colonic apical membranes--a comparative study. Comp Biochem Physiol C Toxicol Pharmacol 2003; 134:329-39. [PMID: 12643980 DOI: 10.1016/s1532-0456(02)00250-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This study compares composition of the rat small intestinal brush border membranes (BBM) and colonic apical membranes (CAM) and their susceptibility to in vitro exposure to various oxidants. Differences were observed between BBM and CAM in their lipid composition, sugar content, alkaline phosphatase (ALP) activity and cholesterol/phospholipid ratio. BBM and CAM were exposed to superoxide generated by xanthine+xanthine oxidase (X-XO) or peroxides such as tertiary butyl hydroperoxide (tBuOOH) and hydrogen peroxide (H(2)O(2)) and alterations in ALP activity, peroxidation parameters and membrane lipids were analyzed. Exposure of BBM and CAM to superoxide resulted in decrease in ALP activity and increase in peroxidation parameters such as protein carbonyl content, malondialdehyde and conjugated diene. Superoxide exposure also resulted in lipid alterations specifically in certain phospholipids. These alterations were prevented either by superoxide dismutase or by allopurinol. Peroxides did not have any significant effect. These results suggest that both BBM and CAM are susceptible to superoxide, which can bring about peroxidation and degradation of membrane lipids specifically, certain phospholipids.
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Affiliation(s)
- R Prabhu
- The Wellcome Trust Research Laboratory, Department of Gastrointestinal Sciences, Christian Medical College and Hospital, Vellore 632004, India
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García D, Delgado R, Ubeira FM, Leiro J. Modulation of rat macrophage function by the Mangifera indica L. extracts Vimang and mangiferin. Int Immunopharmacol 2002; 2:797-806. [PMID: 12095170 DOI: 10.1016/s1567-5769(02)00018-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Vimang is an aqueous extract of Mangiferia indica L., traditionally used in Cuba as an anti-inflammatory, analgesic and antioxidant. In the present study, we investigated the effects of Vimang and of mangiferin (a C-glucosylxanthone present in the extract) on rat macrophage functions including phagocytic activity and the respiratory burst. Both Vimang and mangiferin showed inhibitory effects on macrophage activity: (a) intraperitoneal doses of only 50-250 mg/kg markedly reduced the number of macrophages in peritoneal exudate following intraperitoneal injection of thioglycollate 5 days previously (though there was no significant effect on the proportion of macrophages in the peritoneal-exudate cell population); (b) in vitro concentrations of 0.1-100 microg/ml reduced the phagocytosis of yeasts cells by resident peritoneal and thioglycollate-elicited macrophages; (c) in vitro concentrations of 1-50 microg/ml reduced nitric oxide (NO) production by thioglycollate-elicited macrophages stimulated in vitro with lipopolysaccharide (LPS) and IFNgamma; and (d) in vitro concentrations of 1-50 microg/ml reduced the extracellular production of reactive oxygen species (ROS) by resident and thioglycollate-elicited macrophages stimulated in vitro with phorbol myristate acetate (PMA). These results suggest that components of Vimang, including the polyphenol mangiferin, have depressor effects on the phagocytic and ROS production activities of rat macrophages and, thus, that they may be of value in the treatment of diseases of immunopathological origin characterized by the hyperactivation of phagocytic cells such as certain autoimmune disorders.
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Affiliation(s)
- D García
- Departamento de Farmacia, Universidad Central de Las Villas, Villa Clara, Cuba
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Derbez AE, Mody RM, Werling LL. Sigma(2)-receptor regulation of dopamine transporter via activation of protein kinase C. J Pharmacol Exp Ther 2002; 301:306-14. [PMID: 11907188 DOI: 10.1124/jpet.301.1.306] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The elucidation of the mechanisms underlying sigma(2)-receptor activation and signal transduction is crucial to the understanding of sigma(2)-receptor function. Previous studies in our laboratory have demonstrated sigma(2)-receptor-mediated regulation of the dopamine transporter (DAT) as measured by amphetamine-stimulated release of [(3)H]dopamine (DA) from both rat striatal slices and PC12 cells. The regulation of the DAT in the PC12 cell model was dependent upon activation of Ca(2+)/calmodulin-dependent kinase II. We have now studied the second messenger systems involved in sigma(2)-receptor-mediated regulation of amphetamine-stimulated [(3)H]DA release in rat striatal slices, including Ca(2+)/calmodulin-dependent kinase II, protein kinase C, and sources of calcium required for the enhancement of release produced by sigma(2)-receptor activation. The Ca(2+)/calmodulin-dependent kinase II inhibitors 1-[N,O-bis-(5-isoquionolinesulfonyl)]-N-methyl-L-tyrosyl-4-phenylpiperazine and N-[2-[[[3-(4'-chlorophenyl)-2-propenyl]methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4'-methoxy-benzenesulfonamide phosphate did not significantly affect the (+)-pentazocine-mediated enhancement of amphetamine-stimulated [(3)H]DA release. However, we found that an inhibitor of protein kinase C, 3-[1-[3-(dimethylamino)propyl]-1H-indol-3-yl)-1H-pyrrole-2,5-dione, blocks the (+)-pentazocine-mediated enhancement in rat striatal slices. The protein kinase C activator phorbol 12-myristate 13-acetate, but not the inactive isophorbol 4 alpha,9 alpha,12 alpha,13 alpha,20-pentahydroxytiglia-1,6-dien-3-one, enhanced the amphetamine-stimulated [(3)H]DA release comparable to the enhancement seen by (+)-pentazocine alone. Additionally, the L-type voltage-dependent calcium channel inhibitor nitrendipine or prior treatment with thapsigargin, but not the N-type voltage-dependent calcium channel omega-conotoxin MVIIA, attenuated the (+)-pentazocine-mediated enhancement. Together, these data suggest that activation of sigma(2)-receptors results in the regulation of DAT activity via a calcium- and protein kinase C-dependent signaling mechanism.
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Affiliation(s)
- Alicia E Derbez
- Department of Pharmacology, The George Washington University Medical Center, Washington, DC 20037, USA
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Abstract
BACKGROUND It has been suggested that homocysteine is implicated in the risk of atherosclerosis and thrombosis. The pathogenic mechanism has not been clarified, but oxygen-free species produced by the homocysteine metabolism and auto-oxidation could have a role. DESIGN We have studied the effect of homocysteine on arachidonic acid release in human platelets. Two important products of arachidonic acid metabolism - thromboxane B2 (TXB2) and reactive oxygen species (ROS) - have been assayed. RESULTS Results indicate that homocysteine induces arachidonic acid release that is partially inhibited by 5,8,11,14-eicosatetraynoic acid (ETYA). Platelet incubation with homocysteine significantly increases basal levels of TXB2 and ROS. The effect is time- and dose-dependent. The TXB2 formation is strictly correlated with the arachidonic acid release. Moreover, ROS accumulation is largely inhibited by ETYA and partially reduced by diphenyleneiodonium (DPI), suggesting the involvement both of enzymes metabolising arachidonic acid (cyclooxygenase, lipooxygenase, cytochrome P450 monooxygenase) and of NAD(P)H oxidase. CONCLUSION Homocysteine induces oxidative stress in human platelets in vitro. The unbalance in platelet redox-state and the increased TXB2 formation may generate hyperactivation, contributing to a thrombogenic state leading to cardiovascular diseases.
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Affiliation(s)
- M G Signorello
- Department of Experimental Medicine, Biochemistry Section, University of Genova, Genova, Italy
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Neiva TJC, Benedetti AL, Tanaka SMCN, Santos JI, D'Amico EA. Determination of serum aluminum, platelet aggregation and lipid peroxidation in hemodialyzed patients. Braz J Med Biol Res 2002; 35:345-50. [PMID: 11887212 DOI: 10.1590/s0100-879x2002000300009] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Aluminum (Al3+) overload is frequently associated with lipid peroxidation and neurological disorders. Aluminum accumulation is also reported to be related to renal impairment, anemia and other clinical complications in hemodialysis patients. The aim of the present study was to determine the degree of lipid peroxidation, platelet aggregation and serum aluminum in patients receiving regular hemodialytic treatment. The level of plasma lipid peroxidation was evaluated on the basis of thiobarbituric acid reactive substances (TBARS). Mean platelet peroxidation in patients undergoing hemodialysis was significantly higher than in normal controls (2.7 +/- 0.03 vs. 1.8 +/- 0.06 nmol/l, P<0.05). Platelet aggregation and serum aluminum levels were determined by a turbidimetric method and atomic absorption spectrophotometry, respectively. Serum aluminum was significantly higher in patients than in normal controls (44.5 +/- 29 vs. 10.8 +/- 2.5 microg/l, P<0.05). Human blood platelets were stimulated with collagen (2.2 microg/ml), adenosine diphosphate (6 microM) and epinephrine (6 microM) and showed reduced function with the three agonists utilized. No correlation between aluminum levels and platelet aggregation or between aluminum and peroxidation was observed in hemodialyzed patients.
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Affiliation(s)
- T J C Neiva
- Departamento de Análises Clínicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brasil.
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Kang J, Park EJ, Jou I, Kim JH, Joe EH. Reactive oxygen species mediate A beta(25-35)-induced activation of BV-2 microglia. Neuroreport 2001; 12:1449-52. [PMID: 11388427 DOI: 10.1097/00001756-200105250-00030] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Microglial activation induced by beta-amyloid (A beta) is an important cellular response in the pathogenesis of Alzheimer's disease (AD). In this study, we show that reactive oxygen species (ROS) play a role as signaling molecules for the activation of NF-kappaB and induction of IL-1beta mRNA expression in A beta(25-35)-treated murine microglia BV-2 cells. ROS scavengers such catalase and superoxide dismutase (SOD) mimetics obviously reduced activation of NF-kappaB and the elevated level of IL-1beta transcripts induced by A beta(25-35). In addition, the A beta(25-35)-induced NF-kappaB activation and IL-1beta expression were suppressed by blockers of the ROS generating enzymes such as NADPH oxidase, cyclooxygenase, and lipoxygenase. These data suggest that ROS mediate A beta-induced microglial activation.
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Affiliation(s)
- J Kang
- Department of Neuroscience, Ajou University School of Medicine, Suwon, Korea
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Drew AE, Werling LL. Protein kinase C regulation of dopamine transporter initiated by nicotinic receptor activation in slices of rat prefrontal cortex. J Neurochem 2001; 77:839-48. [PMID: 11331413 DOI: 10.1046/j.1471-4159.2001.00293.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We previously reported that activation of nicotinic receptors causes an enhancement in amphetamine-stimulated release of dopamine via its transporter from slices of prefrontal cortex, but no such enhancement of release from slices of nucleus accumbens or striatum. The nicotinic receptors mediating the enhancement most likely contain alpha4 and beta2 subunits based upon pharmacological characterization. In this study, we sought to characterize the second messenger systems associated with the nicotine-mediated response. Sodium channel involvement was confirmed by the observation that tetrodotoxin blocked nicotine-mediated enhancement, whereas veratridine or elevated K(+) mimicked the enhancement seen with nicotine. Inclusion of EGTA blocked nicotine-mediated enhancement, suggesting that, even though no exogenous Ca(2+) was added, endogenous stores were required for the enhancement. The enhancement by nicotine was also abolished by the L-type voltage-dependent calcium channel (VDCC) antagonist nitrendipine, but not by the N-type VDCC antagonist omega-conotoxin GVIA. Finally, inhibition of protein kinase C also abolished the nicotine-mediated enhancement of amphetamine-stimulated dopamine release, whereas inhibitors of Ca(2+)/calmodulin kinase II did not. These findings establish that nicotine can exert selective effects on dopamine transporter activity in prefrontal cortex, an area involved in cognition and learning.
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Affiliation(s)
- A E Drew
- Department of Pharmacology, The George Washington University Medical Center, Washington DC 20037, USA
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Mori A, Yasuda Y, Murayama T, Nomura Y. Enhancement of arachidonic acid release and prostaglandin F(2alpha) formation by Na3VO4 in PC12 cells and GH3 cells. Eur J Pharmacol 2001; 417:19-25. [PMID: 11301055 DOI: 10.1016/s0014-2999(01)00871-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Both activation of phospholipase A2 causing arachidonic acid release and tyrosine phosphorylation have been proposed to be involved in neuronal functions. Previously, we reported that orthovanadate (Na3VO4), an inhibitor of tyrosine phosphatases, stimulated tyrosine phosphorylation in proteins and enhanced Ca2+-induced noradrenaline release in rat pheochromocytoma PC12 cells. However, the role of tyrosine phosphorylation on phospholipase A2 activity and/or arachidonic acid release in neuronal cells has not been well established. The effects of Na3VO4 on arachidonic acid release and prostaglandin F(2alpha) formation were investigated in two types of neuronal cell lines. In PC12 cells, addition of Na3VO4 stimulated [3H]arachidonic acid release and prostaglandin F(2alpha) formation in a concentration-dependent manner. Co-addition of 5 mM Na3VO4 enhanced ionomycin-stimulated [3H]arachidonic acid release. Na3VO4 also enhanced ionomycin-stimulated [3H]arachidonic acid release from GH3 cells, a clonal strain from rat anterior pituitary. These findings suggest that the tyrosine phosphorylation pathway regulates arachidonic acid release by phospholipase A2 and prostaglandin F(2alpha) formation in neuronal cells.
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Affiliation(s)
- A Mori
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Hokkaido University, 060-0812, Sapporo, Japan
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37
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Malaviya R, Malaviya R, Uckun FM. Anti-inflammatory activity of 2,4, 6-trihydroxy-alpha-p-methoxyphenyl-acetophenone (compound D-58). Dermatology 2001; 201:337-42. [PMID: 11146345 DOI: 10.1159/000051549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Active oxygen radicals as well as a variety of cytosolic protein tyrosine kinases play a role in the regulation of prostaglandin E(2) (PGE(2)), a key inflammatory mediator, released by skin cells in response to irradiation with ultraviolet B light (UVB). Identification of chemical compounds that can interrupt such events may provide a basis for the development of potent anti-inflammatory agents. OBJECTIVE To investigate the effect of a novel genistein analog, 2,4, 6-trihydroxy-alpha-p-methoxyphenylacetophenone, with antioxidant property (compound D-58), on UVB-induced inflammatory responses. METHODS Epidermal cell cultures were irradiated with UVB both in the presence and absence of compound D-58 and the PGE(2) released in the medium was determined by ELISA. For in vivo studies, skin inflammation was induced in mice either by carrageenan challenge of the air pouch or by an acute exposure of skin to UVB radiation. The resulting inflammatory mediator release, skin edema and the histological changes of the skin were determined both in the presence and absence of compound D-58. RESULTS Compound D-58 treatment effectively inhibited the development of edema and histological changes in the skin of UVB-irradiated mice as well as the release of PGE(2) in vitro as well as in vivo. CONCLUSION Compound D-58 (2,4,6-trihydroxy-alpha-p-methoxyphenylacetophenone) has potent anti-inflammatory properties.
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Affiliation(s)
- R Malaviya
- Drug Discovery Program, Departments of Allergy and Inflammatory Diseases, Parker Hughes Institute, St. Paul, MN 55113, USA
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Gamaley IA, Klyubin IV. Roles of reactive oxygen species: signaling and regulation of cellular functions. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 188:203-55. [PMID: 10208013 DOI: 10.1016/s0074-7696(08)61568-5] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Reactive oxygen species (ROS) are the side products (H2O2, O2.-, and OH.) of general metabolism and are also produced specifically by the NADPH oxidase system in most cell types. Cells have a very efficient antioxidant defense to counteract the toxic effect of ROS. The physiological significance of ROS is that ROS at low concentrations are able to mediate cellular functions through the same steps of intracellular signaling, which are activated by natural stimuli. Moreover, a variety of natural stimuli act through the intracellular formation of ROS that change the intracellular redox state (oxidation-reduction). Thus, the redox state is a part of intracellular signaling. As such, ROS are now considered signal molecules at nontoxic concentrations. Progress has been achieved in studying the oxidative activation of gene transcription in animal cells and bacteria. Changes in the redox state of intracellular thiols are considered to be an important mechanism that regulates cell functions.
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Affiliation(s)
- I A Gamaley
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
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39
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Leoncini G, Signorello MG. N-ethylmaleimide-stimulated arachidonic acid release in human platelets. Biochem Pharmacol 1999; 57:785-91. [PMID: 10075084 DOI: 10.1016/s0006-2952(98)00358-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Treatment of human platelets with the alkylating agent N-ethylmaleimide (NEM) induces arachidonic acid release. The effect was time- and dose-dependent. NEM-stimulated arachidonic acid mobilisation could be prevented by pretreating platelets with the cytosolic phospholipase A2 (cPLA2)-specific inhibitor arachidonyltrifluoromethyl ketone. Moreover, the tyrosine kinase inhibitor genistein was able to significantly inhibit arachidonic acid mobilisation. NEM-stimulated release of arachidonic acid appears to be a Ca2+-dependent mechanism, as shown by the observation that arachidonic acid mobilisation was significantly reduced by platelet treatment with EGTA and abolished by preloading platelets with the intracellular chelator 1,2-bis (o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid tetra (acetoxymethyl) ester (BAPTA/AM). In Fura-2-loaded platelets, NEM was able to significantly increase the intracellular Ca2+ level. The Ca2+ elevation was significantly reduced in the presence of EGTA and suppressed by cell treatment with BAPTA/AM. Arachidonic acid released by NEM produced a significant increase in reactive oxygen species (ROS) intracellular levels, which was partially inhibited by diphenyleneiodonium and almost completely suppressed by 5,8,11,14-eicosatetraynoic acid. In conclusion, the results in this study demonstrate that NEM stimulates arachidonic acid release by cPLA2 activation through intracellular Ca2+ elevation. In addition, tyrosine specific protein kinases seem to be involved in arachidonic acid release. ROS was also shown to be formed during arachidonic acid metabolisation.
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Affiliation(s)
- G Leoncini
- Istituto di Chimica Biologica, Universita di Genova, Genoa, Italy.
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40
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Brown JF, Chang Q, Soper BD, Tepperman BL. Protein kinase C mediates experimental colitis in the rat. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:G583-90. [PMID: 10070033 DOI: 10.1152/ajpgi.1999.276.3.g583] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Protein kinase C (PKC) plays an important role in the cell signal transduction of many physiological processes. In contrast to these physiological responses, increases in PKC activity have also been associated with inflammatory disease states, including ulcerative colitis. The objective of this study was to examine the role of PKC as a causative mediator in initiation of experimentally induced colitis in the rat. Colitis was induced in rats by intrarectal (0.6 ml) instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS; 75 mg/kg in 50% ethanol) or the PKC activator phorbol 12-myristate 13-acetate (PMA; 1.5-3.0 mg/kg in 20% ethanol). Gross and histological mucosal damage, mucosal neutrophil infiltration, mucosal PKC activity, and PKC protein content for PKC isoforms alpha, beta, delta, and epsilon were assessed 2 h to 14 days after an inflammatory challenge. Both PKC activity and mucosal injury increased significantly within 4 h of TNBS treatment. PKC activity was maximal at 7 days and declined at 14 days, whereas mucosal damage became maximal at 1 day and declined after 7 days. In contrast, neutrophil infiltration as assessed by myeloperoxidase activity only increased 12 h after TNBS treatment, became maximal 1 day after TNBS administration, and declined thereafter. PKCbeta, -delta, and -epsilon were increased in response to TNBS, whereas PKCalpha protein content was decreased. The PKC antagonists staurosporine and GF-109203X (25 ng/kg iv) reduced TNBS-induced changes in mucosal PKC activity and the degree of mucosal damage. In contrast, neutropenia induced by antineutrophil serum treatment did not significantly affect the degree of injury or mucosal PKC activity. Furthermore, activation of mucosal PKC activity with PMA also induced mucosal damage, which was also inhibited by pretreatment with a PKC antagonist. In conclusion, these results suggest that increases in PKC activity play a causative role in TNBS-induced colitis. The PKC-mediated response to TNBS does not appear to involve neutrophil infiltration.
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Affiliation(s)
- J F Brown
- Department of Physiology, Faculty of Medicine, University of Western Ontario, London, Ontario, Canada N6A 5C1
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41
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Abstract
Extracellular stimuli elicit a variety of responses, such as cell proliferation and differentiation, through the cellular signalling system. Binding of growth factors to the respective receptor leads to the activation of receptor tyrosine kinases, which in turn stimulate downstream signalling systems such as mitogen-activated protein (MAP) kinases, phospholipase Cgamma (PLCgamma) and phosphatidylinositol 3-kinase. These biochemical reactions finally reach the nucleus, resulting in gene expression mediated by the activation of several transcription factors. Recent studies have revealed that cellular signalling pathways are regulated by the intracellular redox state. Generation of reactive oxygen species (ROS), such as H2O2, leads to the activation of protein tyrosine kinases followed by the stimulation of downstream signalling systems including MAP kinase and PLCgamma. The activation of PLCgamma by oxidative radical stress elevates the cellular Ca2+ levels by flux from the intracellular Ca2+ pool and from the extracellular space. Such reactions in the upstream signalling cascade, in concert, result in the activation of several transcription factors. On the other hand, reductants generally suppress the upstream signalling cascade resulting in the suppression of transcription factors. However, it is well known that cysteine residues in a reduced state are essential for the activity of many transcription factors. In fact, in vitro, oxidation of NFkappaB results in its activation, whereas reductants promote its activity. Thus, cellular signalling pathways are generally subjected to dual redox regulation in which redox has opposite effects on upstream signalling systems and downstream transcription factors. Not only are the cellular signalling pathways subjected to redox regulation, but also the signalling systems regulate the cellular redox state. When cells are activated by extracellular stimuli, the cells produce ROS, which in turn stimulate other cellular signalling pathways, indicating that ROS act as second messengers. It is thus evident that there is cross talk between the cellular signalling system and the cellular redox state. Cell death and life also are subjected to such dual redox regulation and cross talk. Death signals induce apoptosis through the activation of caspases in the cells. Oxidative radical stress induces the activation of caspases, whereas the oxidation of caspases results in their inactivation. Furthermore, some cell-death signals induce the production of ROS in the cells, and the ROS produced in turn stimulate the cell-death machinery. All this evidence shows that the cell's fate is determined by cross talk between the cellular signalling pathways and the cellular redox state through a complicated regulation mechanism.
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Affiliation(s)
- H Kamata
- Department of Life Science, Faculty of Science, Himeji Institute of Technology, Hyogo, Japan.
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Goldman R, Moshonov S, Chen X, Berchansky A, Fürstenberger G, Zor U. Crosstalk between elevation of [Ca2+]i, reactive oxygen species generation and phospholipase A2 stimulation in a human keratinocyte cell line. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 433:41-5. [PMID: 9561100 DOI: 10.1007/978-1-4899-1810-9_7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The aim of the study was to explore the possible interrelationship between reactive oxygen species (ROS) formation and cPLA2 activation and the mediator role that [Ca2+]i may play in these processes in the human keratinocyte cell line, HaCaT. HaCaT cells can be invoked to transiently produce ROS by epidermal growth factor (EGF), thapsigargin (TPG) and the Ca(2+)-ionophore, A23187. These 3 agonists transiently increase [Ca2+]i with characteristic kinetics and magnitude. TPG and A23187 each activates on its own [3H]AA release from prelabeled cells, whereas EGF on its own has no effect on [3H]AA release. However, EGF augments [3H]AA release invoked by TPG or A23187 several fold. EGF activates MAP kinase cascades in HaCaT cells, leads to ROS formation and induces relatively small (1.6 fold) elevation in [Ca2+]i, whereas A23187 and TPG lead to a substantial elevation in [Ca2+]i (2.5 to 5 fold) and to ROS formation. Both have a minor effect on MAP kinase activation. The synergism in PLA2 activation by EGF and TPG or A23187, and the sensitivity of [3H]AA release to N-acetylcysteine (NAC) and dithiothreitol (DTT) (potent reducing agents) or to DPI (an inhibitor of FAD-dependent oxidases) lead to the suggestion that ROS formation, elevation of [Ca2+]i and PLA2 activation are causally related. Since we show that elevation of [Ca2+]i is a prerequisite for both ROS and PLA2 activation, it is possible that these processes contribute to the toxicity (apoptosis) exerted by chronic elevation of [Ca2+]i.
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Affiliation(s)
- R Goldman
- Department of Membrane Research and Biophysics, Weizmann Institute of Science, Rehovot, Israel
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Goldman R, Ferber E, Zor U. Involvement of reactive oxygen species in phospholipase A2 activation: inhibition of protein tyrosine phosphatases and activation of protein kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 400A:25-30. [PMID: 9547533 DOI: 10.1007/978-1-4615-5325-0_4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Activators of PKC in combination with vanadate induce massive formation of reactive oxygen species. The formation of ROS leads to suppression of protein tyrosine phosphatase activity and consequently to enhanced protein tyrosine phosphorylation. This culminates in the activation of the MAP-K cascade and of PLA2 (Scheme 1).
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Affiliation(s)
- R Goldman
- Department of Membrane Research and Biophysics, Weizmann Institute of Science, Rehovot, Israel
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44
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Kaul N, Gopalakrishna R, Gundimeda U, Choi J, Forman HJ. Role of protein kinase C in basal and hydrogen peroxide-stimulated NF-kappa B activation in the murine macrophage J774A.1 cell line. Arch Biochem Biophys 1998; 350:79-86. [PMID: 9466823 DOI: 10.1006/abbi.1997.0487] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In macrophages, hydrogen peroxide appears to be a physiological activator of the transcription factor, nuclear factor kappa B (NF-kappa B); however, the molecular basis of H2O2-stimulated NF-kappa B activation is not well defined. The observations that NF-kappa B can be activated in cells by phorbol 12-myristate 13-acetate and in vitro by addition of protein kinase C (PKC) are suggestive of a role of PKC in NF-kappa B activation, which was investigated in the J774A.1 murine macrophage cell line. Basal NF-kappa B DNA-binding activity and nuclear localization were decreased by PKC inhibitors. Although PKC activity was modified by H2O2 with a similar time course as H2O2 activation of NF-kappa B, the H2O2-stimulated increase in NF-kappa B DNA binding and translocation to the nucleus was unaffected by PKC inhibitors. Furthermore, PKC down-regulation (through preincubation with phorbol esters) also affected only baseline NF-kappa B DNA binding but not H2O2-stimulated NF-kappa B activation. Buffering of changes in intracellular free calcium concentration also had no effect upon H2O2-stimulated NF-kappa B activation. Thus, classical PKC activity may modulate basal NF-kappa B activity but does not participate in H2O2-stimulated NF-kappa B activation.
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Affiliation(s)
- N Kaul
- Department of Molecular Pharmacology & Toxicology, University of Southern California, Los Angeles 90033, USA
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45
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Goldman R, Moshonov S, Zor U. Generation of reactive oxygen species in a human keratinocyte cell line: role of calcium. Arch Biochem Biophys 1998; 350:10-8. [PMID: 9466814 DOI: 10.1006/abbi.1997.0478] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the human keratinocyte cell line HaCaT, reactive oxygen species (ROS) were generated in a dose- and time-dependent manner in response to epidermal growth factor (EGF), bradykinin, thapsigargin, and the Ca(2+)-ionophore A23187, agonists that interact with different primary cell targets. ROS formation was assessed by both chemiluminescence- and fluorescence-based methods. The ROS evoked by EGF and bradykinin decayed within 8 and 4 min, respectively, this transient effect resulting probably from down-regulation of the specific agonist receptors or dissipation of the secondary signals. In contrast, the response to thapsigargin and A23187 was sustained for at least 15 min. Extracellular Ca2+ and a rise in intracellular Ca2+ concentration ([Ca2+]i) proved essential for ROS production. Chelation by BAPTA suppressed ROS formation. Direct measurement of [Ca2+]i using fura fluorescence revealed that EGF and bradykinin evoked a modest, transient [Ca2+]i elevation of less than twofold, whereas with thapsigargin and A23187 there was a sustained two- to fourfold elevation. For each agonist, the kinetics of the rise and decay of [Ca2+]i were similar to those of ROS. The enzyme(s) involved in ROS formation were inhibited by diphenyleneiodonium, indicating dependence on FAD. Our results suggest a close link between ROS and changes in [Ca2+]i generated by growth factors and hormones. This is a particularly interesting connection because elevation of ROS and/ or [Ca2+]i has been linked to cell proliferation, differentiation, and apoptosis.
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Affiliation(s)
- R Goldman
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
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Abstract
Research into the cell biology of mammalian fertilization has been stimulated by the desire to provide a theoretical framework for the development of novel approaches to contraception and the need to understand the cellular basis of human infertility. The results of such studies have revealed a complex cascade of interactions initiated by the contact between capacitated spermatozoa on the oocyte-cumulus complex and culminating in sperm-oocyte fusion. In this review we shall examine our current understanding of the fertilization process, highlighting the strategic importance of recent findings and key areas where information is lacking.
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Affiliation(s)
- R J Aitken
- MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, Scotland
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47
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Katsuki H, Nakanishi C, Saito H, Matsuki N. Biphasic effect of hydrogen peroxide on field potentials in rat hippocampal slices. Eur J Pharmacol 1997; 337:213-8. [PMID: 9430416 DOI: 10.1016/s0014-2999(97)01323-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the CA1 region of rat hippocampal slices, H2O2 (0.294-2.94 mM) caused initial augmentation, and subsequent long-lasting depression, of population spikes and excitatory postsynaptic potentials. The effect of H2O2 may not be mediated by its degradation product, hydroxyl radicals, because an iron chelator deferoxamine did not block the effect. A catalase inhibitor 3-amino-1,2,4-triazole only modestly attenuated the initial augmentation, suggesting that the effect of H2O2 is not attributable to catalase-dependent O2 generation, either. An N-methyl-D-aspartate receptor antagonist DL-2-amino-5-phosphonovaleric acid had no influence on the effect of H2O2, whereas a gamma-aminobutyric acid type A receptor channel blocker picrotoxin attenuated long-lasting depression, indicating that gamma-aminobutyric acid-mediated inhibition is altered during the depression phase. The initial augmentation but not subsequent depression was attenuated by a phospholipase A2/C inhibitor 4-bromophenacyl bromide, suggesting the involvement of lipid signaling molecule(s) in the enhancement of excitatory synaptic transmission. These results suggest that H2O2 regulates hippocampal synaptic transmission via multiple mechanisms.
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Affiliation(s)
- H Katsuki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan
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48
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Aitken RJ, Fisher HM, Fulton N, Gomez E, Knox W, Lewis B, Irvine S. Reactive oxygen species generation by human spermatozoa is induced by exogenous NADPH and inhibited by the flavoprotein inhibitors diphenylene iodonium and quinacrine. Mol Reprod Dev 1997; 47:468-82. [PMID: 9211432 DOI: 10.1002/(sici)1098-2795(199708)47:4<468::aid-mrd14>3.0.co;2-s] [Citation(s) in RCA: 183] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Human spermatozoa possess a specialized capacity to generate reactive oxygen species (ROS) that is thought to be of significance in the redox regulation of sperm capacitation (De Lamirande and Gagnon, 1993; Aitken et al., 1995). However, the mechanisms by which ROS are generated by these cells are not understood. In this study we have examined the possible significance of NADPH as a substrate for ROS production by human spermatozoa. Addition of NADPH to viable populations of motile spermatozoa induced a sudden dose-dependent increase in the rate of superoxide generation via mechanisms that could not be disrupted by inhibitors of the mitochondrial electron transport chain (antimycin A, rotenone, carbonyl cyanide m-chlorophenylhydrazone [CCCP], and sodium azide), diaphorase (dicoumarol) xanthine oxidase (allopurinol), or lactic acid dehydrogenase (sodium oxamate). However, NADPH-induced ROS generation could be stimulated by permeabilization and was negatively correlated with sperm function. Both NADH and NADPH were active electron donors in this system, while NAD+ and NADP+ exhibited little activity. Stereo-specificity was evident in the response in that only the beta-isomer of NADPH supported superoxide production. The involvement of a flavoprotein in the electron transfer process was indicated by the high sensitivity of the oxidase to inhibition by diphenylene iodonium and quinacrine. These results indicate that NAD(P)H can serve as an electron donor for superoxide generation by human spermatozoa and present a simple strategy for the production of motile populations of free radical generating cells with which to study the significance of these molecules in the control of normal and pathological sperm function.
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Affiliation(s)
- R J Aitken
- MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, Scotland
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49
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Neiva TJ, Fries DM, Monteiro HP, D'Amico EA, Chamone DA. Aluminum induces lipid peroxidation and aggregation of human blood platelets. Braz J Med Biol Res 1997; 30:599-604. [PMID: 9283626 DOI: 10.1590/s0100-879x1997000500005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aluminum (Al3+) intoxication is thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations arising from long-term hemodialysis. Although the metal does not present redox capacity, it can stimulate tissue lipid peroxidation in animal models. Furthermore, in vitro studies have revealed that the fluoroaluminate complex induces diacylglycerol formation, 43-kDa protein phosphorylation and aggregation. Based on these observations, we postulated that Al(3+) -induced blood platelet aggregation was mediated by lipid peroxidation. Using chemiluminescence (CL) of luminol as an index of total lipid peroxidation capacity, we established a correlation between lipid peroxidation capacity and platelet aggregation. Al3+ (20-100 microM) stimulated CL production by human blood platelets as well as their aggregation. Incubation of the platelets with the antioxidants nor-dihydroguaiaretic acid (NDGA) (100 microM) and n-propyl gallate (NPG) (100 microM), inhibitors of the lipoxygenase pathway, completely prevented CL and platelet aggregation. Acetyl salicylic acid (ASA) (100 microM), an inhibitor of the cyclooxygenase pathway, was a weaker inhibitor of both events. These findings suggest that Al3+ stimulates lipid peroxidation and the lipoxygenase pathway in human blood platelets thereby causing their aggregation.
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Affiliation(s)
- T J Neiva
- Departamento de Análises Clínicas, Universidade Federal de Santa Catarina, Florianópolis, Brasil
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50
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Chabannes B, Perraut C, El Habib R, Moliere P, Pacheco Y, Lagarde M. Correlation between arachidonic acid oxygenation and luminol-induced chemiluminescence in neutrophils: inhibition by diethyldithiocarbamate. Biochem Pharmacol 1997; 53:927-35. [PMID: 9174105 DOI: 10.1016/s0006-2952(96)00832-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Neutrophils from allergic subjects were hypersensitive to stimulation by low calcium ionophore concentration (0.15 microM), resulting in an increased formation of leukotriene B4 (LTB4), 5S-hydroxy-6,8,11,14-(E,Z,Z,Z)-eicosatetraenoic acid (5-HETE), and other arachidonic acid metabolites through the 5-lipoxygenase pathway. In parallel, luminol-dependent chemiluminescence was also higher in neutrophils from allergic patients at the basal state and after stimulation by calcium ionophore, revealing an enhancement of radical oxygen species and peroxide production. The activity of glutathione peroxidase, the main enzyme responsible for hydroperoxide reduction, was lowered in these cells. Diethyl-dithiocarbamate (DTC) induced a concentration-dependent decrease in chemiluminescence and arachidonic acid metabolism after neutrophil stimulation. These data show that the elevation of arachidonic acid metabolism in neutrophils from allergic patients is strongly correlated with oxidative status. This elevation may be the consequence of an increased cellular hydroperoxide known to activate 5-lipoxygenase (5-LOX) activity and/or an increased arachidonic acid availability, due either to phospholipase A2 (PLA2) activation or inhibition of arachidonate reesterification into phospholipids. Lowering this oxidative status was associated with a concomitant decrease of this metabolism. Our results suggest that the effect of DTC may be the consequence of an inhibition of peroxyl radical and cellular lipid hydroperoxide production. Thus, DTC may modulate arachidonic acid metabolism in neutrophils by modulating the cellular hydroperoxide level.
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Affiliation(s)
- B Chabannes
- INSERM U352, Laboratoire de Biochimie et Pharmacologie, Institut National des Sciences Appliquees, Villeurbanne, France
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