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Naidu P, Holford M. Microscopic marvels: Decoding the role of micropeptides in innate immunity. Immunology 2024. [PMID: 39188052 DOI: 10.1111/imm.13850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 07/30/2024] [Indexed: 08/28/2024] Open
Abstract
The innate immune response is under selection pressures from changing environments and pathogens. While sequence evolution can be studied by comparing rates of amino acid mutations within and between species, how a gene's birth and death contribute to the evolution of immunity is less known. Short open reading frames, once regarded as untranslated or transcriptional noise, can often produce micropeptides of <100 amino acids with a wide array of biological functions. Some micropeptide sequences are well conserved, whereas others have no evolutionary conservation, potentially representing new functional compounds that arise from species-specific adaptations. To date, few reports have described the discovery of novel micropeptides of the innate immune system. The diversity of immune-related micropeptides is a blind spot for gene and functional annotation. Immune-related micropeptides represent a potential reservoir of untapped compounds for understanding and treating disease. This review consolidates what is currently known about the evolution and function of innate immune-related micropeptides to facilitate their investigation.
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Affiliation(s)
- Praveena Naidu
- Graduate Center, Programs in Biology, Biochemistry, Chemistry, City University of New York, New York, New York, USA
- Department of Chemistry and Biochemistry, City University of New York, Hunter College, Belfer Research Building, New York, New York, USA
| | - Mandë Holford
- Graduate Center, Programs in Biology, Biochemistry, Chemistry, City University of New York, New York, New York, USA
- Department of Chemistry and Biochemistry, City University of New York, Hunter College, Belfer Research Building, New York, New York, USA
- American Museum of Natural History, Invertebrate Zoology, Sackler Institute for Comparative Genomics, New York, New York, USA
- Weill Cornell Medicine, Department of Biochemistry, New York, New York, USA
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Jiang Y, Liu Q, Alfredsson L, Klareskog L, Kockum I, Jiang X. A genome-wide cross-trait analysis identifies genomic correlation, pleiotropic loci, and causal relationship between sex hormone-binding globulin and rheumatoid arthritis. Hum Genomics 2023; 17:81. [PMID: 37644603 PMCID: PMC10466838 DOI: 10.1186/s40246-023-00528-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/21/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND Our study aims to investigate an intrinsic link underlying sex hormone-binding globulin (SHBG) and rheumatoid arthritis (RA), which remains inconclusive in observational settings. METHODS Summary statistics were collected from the largest GWAS(s) on SHBG adjusted for BMI (SHBGadjBMI; Noverall = 368,929; Nmen = 180,094; Nwomen = 188,908), crude SHBG (Noverall = 370,125; Nmen = 180,726; Nwomen = 189,473), and RA (Ncase = 22,350; Ncontrol = 74,823). A genome-wide cross-trait design was performed to quantify global and local genetic correlation, identify pleiotropic loci, and infer a causal relationship. RESULTS Among the overall population, a significant global genetic correlation was observed for SHBGadjBMI and RA ([Formula: see text] = 0.11, P = 1.0 × 10-4) which was further supported by local signal (1q25.2). A total of 18 independent pleiotropic SNPs were identified, of which three were highly likely causal variants and four were found to have effects on both traits through gene expression mediation. A putative causal association of SHBGadjBMI on RA was demonstrated (OR = 1.20, 95% CI = 1.01-1.43) without evidence of reverse causality (OR = 0.999, 95% CI = 0.997-1.000). Sex-specific analyses revealed distinct shared genetic regions (men: 1q32.1-q32.2 and 5p13.1; women: 1q25.2 and 22q11.21-q11.22) and diverse pleiotropic SNPs (16 in men and 18 in women, nearly half were sex-specific) underlying SHBGadjBMI and RA, demonstrating biological disparities between sexes. Replacing SHBGadjBMI with crude SHBG, a largely similar yet less significant pattern of results was observed. CONCLUSION Our cross-trait analysis suggests an intrinsic, as well as a sex-specific, link underlying SHBG and RA, providing novel insights into disease etiology.
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Affiliation(s)
- Yuan Jiang
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Visionsgatan 18, 171 77, Solna, Stockholm, Sweden
| | - Qianwen Liu
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Visionsgatan 18, 171 77, Solna, Stockholm, Sweden
| | - Lars Alfredsson
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Visionsgatan 18, 171 77, Solna, Stockholm, Sweden
- Institute of Environmental Medicine, Karolinska Institutet, Solna, Stockholm, Sweden
| | - Lars Klareskog
- Department of Medicine, Karolinska Institutet, Solna, Stockholm, Sweden
| | - Ingrid Kockum
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Visionsgatan 18, 171 77, Solna, Stockholm, Sweden
| | - Xia Jiang
- Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Visionsgatan 18, 171 77, Solna, Stockholm, Sweden.
- Department of Epidemiology and Biostatistics, Institute of Systems Epidemiology, and West China-PUMC C. C. Chen Institute of Health, West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, Sichuan, China.
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Ahangar Davoodi N, Najafi S, Naderi Ghale-Noie Z, Piranviseh A, Mollazadeh S, Ahmadi Asouri S, Asemi Z, Morshedi M, Tamehri Zadeh SS, Hamblin MR, Sheida A, Mirzaei H. Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression. Front Cell Dev Biol 2022; 10:1065837. [PMID: 36619866 PMCID: PMC9816416 DOI: 10.3389/fcell.2022.1065837] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.
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Affiliation(s)
- Nasrin Ahangar Davoodi
- Eye Research Center, Rassoul Akram Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Sajad Najafi
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zari Naderi Ghale-Noie
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ashkan Piranviseh
- Brain and Spinal Cord Injury Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Samaneh Mollazadeh
- Natural Products and Medicinal Plants Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Sahar Ahmadi Asouri
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Zatollah Asemi
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran
| | - Mohammadamin Morshedi
- Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran,School of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | | | - Michael R. Hamblin
- Laser Research Centre, Faculty of Health Science, University of Johannesburg, Doornfontein, South Africa
| | - Amirhossein Sheida
- Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran,School of Medicine, Kashan University of Medical Sciences, Kashan, Iran,*Correspondence: Amirhossein Sheida, ; Hamed Mirzaei, ,
| | - Hamed Mirzaei
- Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran,*Correspondence: Amirhossein Sheida, ; Hamed Mirzaei, ,
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Lee JH, Jang EH, Kim SA. Brain Region and Sex-specific Changes in Mitochondrial Biogenesis Induced by Acute Trimethyltin Exposure. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2022; 20:474-481. [PMID: 35879031 PMCID: PMC9329116 DOI: 10.9758/cpn.2022.20.3.474] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/24/2021] [Accepted: 03/10/2021] [Indexed: 11/25/2022]
Abstract
Objective In this study, we investigated sex- and region-specific effects of acute trimethyltin (TMT) exposure on mitochondrial biogenesis. Methods We treated TMT to primary neuronal cultures and 4-week-old male and female mice. We measured the mitochondrial DNA copy numbers using the quantitative polymerase chain reaction method. We also measured mitochondrial biogenesis related genes (sirtuin-1, estrogen-related receptor alpha, cytochrome C oxidase subunit IV) by western blotting. Results The mitochondrial DNA copy number increased in the primary hippocampal neuron; however, it decreased in the primary cortical neuron. The mitochondrial copy number increased in the hippocampus and decreased in the cortex in the TMT treated female mice, though the mitochondrial copy number increased in both cortex and hippocampus in the TMT treated male mice. TMT treatment increased sirtuin-1 expression in the male hippocampus but did not in the female brain. In the female brain, estrogen-related receptor alpha expression decreased in the cortex though there is no significant change in the male brain. The protein level of mitochondrial protein, cytochrome C oxidase subunit IV, increased in both cortex and hippocampus after TMT injection in male mice brain, but not in female mice brain. Conclusion Our data suggest that acute TMT exposure induces distinct sex-specific metabolic characteristics in the brain before significant sexual maturation.
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Affiliation(s)
- Jung Ho Lee
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, Korea
| | - Eun Hye Jang
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, Korea
| | - Soon Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon, Korea
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Kim SA, Chai JH, Jang EH. Prenatal Trimethyltin Exposure Induces Long-Term DNA Methylation Changes in the Male Mouse Hippocampus. Int J Mol Sci 2021; 22:ijms22158009. [PMID: 34360774 PMCID: PMC8348768 DOI: 10.3390/ijms22158009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/14/2021] [Accepted: 07/23/2021] [Indexed: 12/12/2022] Open
Abstract
Trimethyltin (TMT) is an irreversible neurotoxicant. Because prenatal TMT exposure has been reported to induce behavioral changes, this study was conducted to observe gender differences and epigenetic changes using a mouse model. In behavioral testing of offspring at 5 weeks of age, the total times spent in the center, corner, or border zones in the male prenatal TMT-exposed mice were less than those of control unexposed mice in the open-field test. Female TMT-exposed mice scored lower on total numbers of arm entries and percentages of alternations than controls in the Y-maze test with lower body weight. We found that only TMT-exposed males had fewer copies of mtDNA in the hippocampus and prefrontal cortex region than controls. Additional epigenetic changes, including increased 5-methyl cytosine/5-hydroxymethyl cytosine levels in the male TMT hippocampus, were observed. After methylation binding domain (MBD) sequencing, multiple signaling pathways related to metabolism and neurodevelopment, including FoxO signaling, were identified by pathway analysis for differentially methylated regions (DMRs). Increased FOXO3 and decreased ASCL1 expression were also observed in male TMT hippocampi. This study suggests that sex differences and epigenetics should be more carefully considered in prenatal toxicology studies.
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Affiliation(s)
- Soon-Ae Kim
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon 34824, Korea;
- Correspondence: ; Tel.: +82-42-259-1672
| | - Jung-Hoon Chai
- Center for Sport Science in Seoul, Seoul Sports Council, Seoul 02119, Korea;
| | - Eun-Hye Jang
- Department of Pharmacology, School of Medicine, Eulji University, Daejeon 34824, Korea;
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Childers GM, Perry CA, Blachut B, Martin N, Bortner CD, Sieber S, Li JL, Fessler MB, Harry GJ. Assessing the Association of Mitochondrial Function and Inflammasome Activation in Murine Macrophages Exposed to Select Mitotoxic Tri-Organotin Compounds. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:47015. [PMID: 33929904 PMCID: PMC8086801 DOI: 10.1289/ehp8314] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
BACKGROUND Mitochondrial function is implicated as a target of environmental toxicants and found in disease or injury models, contributing to acute and chronic inflammation. One mechanism by which mitochondrial damage can propagate inflammation is via activation of the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family, pyrin domain-containing receptor (NLRP)3 inflammasome, a protein complex that processes mature interleukin (IL)-1β. IL-1β plays an important role in the innate immune response and dysregulation is associated with autoinflammatory disorders. OBJECTIVE The objective was to evaluate whether mitochondrial toxicants recruit inflammasome activation and IL-1β processing. METHOD Murine macrophages (RAW 264.7) exposed to tri-organotins (triethyltin bromide (TETBr), trimethyltin hydroxide (TMTOH), triphenyltin hydroxide (TPTOH), bis(tributyltin)oxide) [Bis(TBT)Ox] were examined for pro-inflammatory cytokine induction. TMTOH and TETBr were examined in RAW 264.7 and bone marrow-derived macrophages for mitochondrial bioenergetics, reactive oxygen species (ROS) production, and inflammasome activation via visualization of aggregate formation, caspase-1 flow cytometry, IL-1β enzyme-linked immunosorbent assay and Western blots, and microRNA (miRNA) and mRNA arrays. RESULTS TETBr and TMTOH induced inflammasome aggregate formation and IL-1β release in lipopolysaccharide (LPS)-primed macrophages. Mitochondrial bioenergetics and mitochondrial ROS were suppressed. Il1a and Il1b induction with LPS or LPS+ATP challenge was diminished. Differential miRNA and mRNA profiles were observed. Lower miR-151-3p targeted cyclic adenosine monophosphate (cAMP)-mediated and AMP-activated protein kinase signaling pathways; higher miR-6909-5p, miR-7044-5p, and miR-7686-5p targeted Wnt beta-catenin signaling, retinoic acid receptor activation, apoptosis, signal transducer and activator of transcription 3, IL-22, IL-12, and IL-10 signaling. Functional enrichment analysis identified apoptosis and cell survival canonical pathways. CONCLUSION Select mitotoxic tri-organotins disrupted murine macrophage transcriptional response to LPS, yet triggered inflammasome activation. The differential response pattern suggested unique functional changes in the inflammatory response that may translate to suppressed host defense or prolong inflammation. We posit a framework to examine immune cell effects of environmental mitotoxic compounds for adverse health outcomes. https://doi.org/10.1289/EHP8314.
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Affiliation(s)
- Gabrielle M. Childers
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Caroline A. Perry
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Barbara Blachut
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
| | - Negin Martin
- Laboratory of Neurobiology, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Carl D. Bortner
- Signal Transduction Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Stella Sieber
- Molecular Genomics Core Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Jian-Liang Li
- Integrative Bioinformatics Support Group, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - Michael B. Fessler
- Immunity, Inflammation, and Disease Laboratory, NIEHS, NIH, DHHS, Research Triangle Park, North Carolina, USA
| | - G. Jean Harry
- Molecular Toxicology Branch, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Research Triangle Park, North Carolina, USA
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Stenroos P, Pirttimäki T, Paasonen J, Paasonen E, Salo RA, Koivisto H, Natunen T, Mäkinen P, Kuulasmaa T, Hiltunen M, Tanila H, Gröhn O. Isoflurane affects brain functional connectivity in rats 1 month after exposure. Neuroimage 2021; 234:117987. [PMID: 33762218 DOI: 10.1016/j.neuroimage.2021.117987] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 02/16/2021] [Accepted: 03/16/2021] [Indexed: 10/21/2022] Open
Abstract
Isoflurane, the most commonly used preclinical anesthetic, induces brain plasticity and long-term cellular and molecular changes leading to behavioral and/or cognitive consequences. These changes are most likely associated with network-level changes in brain function. To elucidate the mechanisms underlying long-term effects of isoflurane, we investigated the influence of a single isoflurane exposure on functional connectivity, brain electrical activity, and gene expression. Male Wistar rats (n = 22) were exposed to 1.8% isoflurane for 3 h. Control rats (n = 22) spent 3 h in the same room without exposure to anesthesia. After 1 month, functional connectivity was evaluated with resting-state functional magnetic resonance imaging (fMRI; n = 6 + 6) and local field potential measurements (n = 6 + 6) in anesthetized animals. A whole genome expression analysis (n = 10+10) was also conducted with mRNA-sequencing from cortical and hippocampal tissue samples. Isoflurane treatment strengthened thalamo-cortical and hippocampal-cortical functional connectivity. Cortical low-frequency fMRI power was also significantly increased in response to the isoflurane treatment. The local field potential results indicating strengthened hippocampal-cortical alpha and beta coherence were in good agreement with the fMRI findings. Furthermore, altered expression was found in 20 cortical genes, several of which are involved in neuronal signal transmission, but no gene expression changes were noted in the hippocampus. Isoflurane induced prolonged changes in thalamo-cortical and hippocampal-cortical function and expression of genes contributing to signal transmission in the cortex. Further studies are required to investigate whether these changes are associated with the postoperative behavioral and cognitive symptoms commonly observed in patients and animals.
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Affiliation(s)
- Petteri Stenroos
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Tiina Pirttimäki
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Jaakko Paasonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Ekaterina Paasonen
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Raimo A Salo
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Hennariikka Koivisto
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Teemu Natunen
- Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Petra Mäkinen
- Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Teemu Kuulasmaa
- Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Mikko Hiltunen
- Institute of Biomedicine, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Heikki Tanila
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
| | - Olli Gröhn
- A.I.Virtanen Institute for Molecular Sciences, University of Eastern Finland, P.O. Box 1627, FI,-70211 Kuopio, Finland
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Acute Trimethyltin Poisoning Caused by Exposure to Polyvinyl Chloride Production: 8 Cases. Am J Med Sci 2021; 362:92-98. [PMID: 33587910 DOI: 10.1016/j.amjms.2021.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 06/30/2020] [Accepted: 02/11/2021] [Indexed: 11/24/2022]
Abstract
This manuscript aimed to describe and analyze acute trimethyltin poisoning caused by exposure to polyvinyl chloride production and review the literature. Combined with an analysis of occupational hygiene survey data, the clinical data of 8 cases of acute trimethyltin poisoning were analyzed retrospectively. The clinical manifestations of acute trimethyltin poisoning are mainly related to central nervous system damage, hypokalemia and metabolic acidosis in patients with severe poisoning. Early positive potassium supplementation and symptomatic treatment are beneficial to the improvement of the condition. The early recognition of central nervous system manifestations and hypokalemia is beneficial for early diagnosis and correct treatment.
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Hu Y, Zhao M, Li L, Ding J, Gui YM, Wei TW. miR-491-3p is Downregulated in Retinoblastoma and Inhibit Tumor Cells Growth and Metastasis by Targeting SNN. Biochem Genet 2020; 59:453-474. [PMID: 33098307 PMCID: PMC7946698 DOI: 10.1007/s10528-020-10007-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 09/29/2020] [Indexed: 02/07/2023]
Abstract
Retinoblastoma (Rb) is the most common pediatric malignant tumor of the eyes. Previous studies demonstrated that miR-491-3p is downregulated in various cancers. However, its function in Rb remains unknown. A total of 15 pairs of primary Rb tissues and adjacent noncancerous tissues were collected. Quantitative real-time PCR (qRT-PCR) was used to investigate the expression profiles of miR-491-3p. qRT-PCR, western blotting and in situ immunocytochemistry were performed to investigate the expression profiles of epithelial–mesenchymal transition-related proteins (E-cadherin, Vimentin and N-cadherin) in Rb tissues and Rb cell lines as well as cell morphology. Cell proliferation was estimated by MTS and colony formation assays. Apoptosis was determined by FACS, cell migration and invasion were analyzed using transwell chambers. MiR-491-3p’s target genes were predicted using target gene prediction databases. The interplay between miR-491-3p and SNN was evaluated through dual luciferase reporter gene assay. MiR-491-3p was significantly downregulated in mixed collection of 15 pairs of Rb tissues and Rb cell lines. Overexpression of miR-491-3p enhanced apoptosis, and significantly suppressed proliferation, migration and invasion of Rb cells. In contrast, the present of miR-491-3p inhibitor showed reversed results which apoptosis decreased, while cell proliferation of ARPE-19 cells increased. In addition, miR-491-3p increased the expression of E-cadherin, and dramatically decreased the expression of Vimentin and N-cadherin in Rb tissues and Rb cell lines, noticeable changes in morphology, too, as cells became less cohesive and more adhering. We found out that SNN was the pairing target of miR-491-3p and result showed that miR-491-3p and SNN interacted with each other. We also found out that the effects of miR-491-3p were in Rb cells were almost entirely canceled out at the overexpression of SNN. Our findings collectively suggest that miR-491-3p is an important tumor suppressor in Rb, which inhibits tumor growth and metastasis in Rb. These implicate it may be explored as a new therapeutic target in Rb.
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Affiliation(s)
- Yang Hu
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China.
| | - Ming Zhao
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China
| | - Li Li
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China
| | - Jie Ding
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China
| | - Yu-Min Gui
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China
| | - Tan-Wei Wei
- Department of Ophthalmology, Puren Hospital of Wuhan University of Science and Technology, No.1 Benxi Road, Qingshan District, Wuhan, 430080, Hubei Province, People's Republic of China
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Park SK, Kang JY, Kim JM, Yoo SK, Han HJ, Chung DH, Kim DO, Kim GH, Heo HJ. Fucoidan-Rich Substances from Ecklonia cava Improve Trimethyltin-Induced Cognitive Dysfunction via Down-Regulation of Amyloid β Production/Tau Hyperphosphorylation. Mar Drugs 2019; 17:E591. [PMID: 31627432 PMCID: PMC6836021 DOI: 10.3390/md17100591] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/04/2019] [Accepted: 10/15/2019] [Indexed: 12/31/2022] Open
Abstract
Ecklonia cava (E. cava) was investigated to compare the effect of polyphenol and fucoidan extract and mixture (polyphenol:fucoidan = 4:6) on cognitive function. The ameliorating effect of E. cava was evaluated using the Y-maze, passive avoidance and Morris water maze tests with a trimethyltin (TMT)-induced cognitive dysfunction model, and the results showed that the fucoidan extract and mixture (4:6) had relatively higher learning and memory function effects than the polyphenol extract. After a behavioral test, the inhibitory effect of lipid peroxidation and cholinergic system activity were examined in mouse brain tissue, and the fucoidan extract and mixture (4:6) also showed greater improvements than the polyphenol extract. Mitochondrial activity was evaluated using mitochondrial reactive oxygen species (ROS) content, mitochondrial membrane potential (MMP, ΔΨm), adenosine triphosphate (ATP) content, and mitochondria-mediated protein (BAX, cytochrome C) analysis, and these results were similar to the results of the behavioral tests. Finally, to confirm the cognitive function-related mechanism of E. cava, the amyloid-β production and tau hyperphosphorylation-medicated proteins were analyzed. Based on these results, the improvement effect of E. cava was more influenced by fucoidan than polyphenol. Therefore, our study suggests that the fucoidan-rich substances in E. cava could be a potential material for improving cognitive function by down-regulating amyloid-β production and tau hyperphosphorylation.
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Affiliation(s)
- Seon Kyeong Park
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
| | - Jin Yong Kang
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
| | - Jong Min Kim
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
| | - Seul Ki Yoo
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
| | - Hye Ju Han
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
| | - Dong Hwa Chung
- Food Technology Major, Graduate School of International Agricultural Technology, Institute of Green Bio Science and Technology, Pyeongchang 25354, Korea.
| | - Dae-Ok Kim
- Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104, Korea.
| | - Gun-Hee Kim
- Departments of Food and Nutrition, Duksung Women's University, Seoul 01369, Korea.
| | - Ho Jin Heo
- Division of Applied Life Science, Institute of Agriculture and Life Science (BK21 plus), Gyeongsang National University, Jinju 52828, Korea.
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11
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Lee S, Yang M, Kim J, Kang S, Kim J, Kim JC, Jung C, Shin T, Kim SH, Moon C. Trimethyltin-induced hippocampal neurodegeneration: A mechanism-based review. Brain Res Bull 2016; 125:187-99. [PMID: 27450702 DOI: 10.1016/j.brainresbull.2016.07.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022]
Abstract
Trimethyltin (TMT), a toxic organotin compound, induces neurodegeneration selectively involving the limbic system and especially prominent in the hippocampus. Neurodegeneration-associated behavioral abnormalities, such as hyperactivity, aggression, cognitive deficits, and epileptic seizures, occur in both exposed humans and experimental animal models. Previously, TMT had been used generally in industry and agriculture, but the use of TMT has been limited because of its dangers to people. TMT has also been used to make a promising in vivo rodent model of neurodegeneration because of its region-specific characteristics. Several studies have demonstrated that TMT-treated animal models of epileptic seizures can be used as tools for researching hippocampus-specific neurotoxicity as well as the molecular mechanisms leading to hippocampal neurodegeneration. This review summarizes the in vivo and in vitro underlying mechanisms of TMT-induced hippocampal neurodegeneration (oxidative stress, inflammatory responses, and neuronal death/survival). Thus, the present review may be helpful to provide general insights into TMT-induced neurodegeneration and approaches to therapeutic interventions for neurodegenerative diseases, including temporal lobe epilepsy.
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Affiliation(s)
- Sueun Lee
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Miyoung Yang
- Department of Anatomy, School of Medicine and Institute for Environmental Science, Wonkwang University, Jeonbuk 54538, South Korea
| | - Jinwook Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Sohi Kang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Juhwan Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Chaeyong Jung
- Department of Anatomy, Chonnam National University Medical School, Gwangju 61469, South Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 63243, South Korea
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea.
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12
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Pueyo JI, Magny EG, Sampson CJ, Amin U, Evans IR, Bishop SA, Couso JP. Hemotin, a Regulator of Phagocytosis Encoded by a Small ORF and Conserved across Metazoans. PLoS Biol 2016; 14:e1002395. [PMID: 27015288 PMCID: PMC4807881 DOI: 10.1371/journal.pbio.1002395] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 01/29/2016] [Indexed: 12/12/2022] Open
Abstract
Translation of hundreds of small ORFs (smORFs) of less than 100 amino acids has recently been revealed in vertebrates and Drosophila. Some of these peptides have essential and conserved cellular functions. In Drosophila, we have predicted a particular smORF class encoding ~80 aa hydrophobic peptides, which may function in membranes and cell organelles. Here, we characterise hemotin, a gene encoding an 88aa transmembrane smORF peptide localised to early endosomes in Drosophila macrophages. hemotin regulates endosomal maturation during phagocytosis by repressing the cooperation of 14-3-3ζ with specific phosphatidylinositol (PI) enzymes. hemotin mutants accumulate undigested phagocytic material inside enlarged endo-lysosomes and as a result, hemotin mutants have reduced ability to fight bacteria, and hence, have severely reduced life span and resistance to infections. We identify Stannin, a peptide involved in organometallic toxicity, as the Hemotin functional homologue in vertebrates, showing that this novel regulator of phagocytic processing is widely conserved, emphasizing the significance of smORF peptides in cell biology and disease.
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Affiliation(s)
- José I. Pueyo
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Emile G. Magny
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | | | - Unum Amin
- School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Iwan R. Evans
- Department of Infection and Immunity and the Bateson Centre, University of Sheffield, Sheffield, South Yorkshire, United Kingdom
| | - Sarah A. Bishop
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
| | - Juan P. Couso
- Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom
- * E-mail:
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13
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Fabrizi C, Pompili E, De Vito S, Somma F, Catizone A, Ricci G, Lenzi P, Fornai F, Fumagalli L. Impairment of the autophagic flux in astrocytes intoxicated by trimethyltin. Neurotoxicology 2015; 52:12-22. [PMID: 26459185 DOI: 10.1016/j.neuro.2015.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 01/10/2023]
Abstract
Autophagy is a lysosomal catabolic route for protein aggregates and damaged organelles which in different stress conditions, such as starvation, generally improves cell survival. An impairment of this degradation pathway has been reported to occur in many neurodegenerative processes. Trimethyltin (TMT) is a potent neurotoxin present as an environmental contaminant causing tremors, seizures and learning impairment in intoxicated subjects. The present data show that in rat primary astrocytes autophagic vesicles (AVs) appeared after few hours of TMT treatment. The analysis of the autophagic flux in TMT-treated astrocytes was consistent with a block of the late stages of autophagy and was accompanied by a progressive accumulation of the microtubule associated protein light chain 3 (LC3) and of p62/SQSTM1. Interestingly, an increased immunoreactivity for p62/SQSTM1 was also observed in hippocampal astrocytes detected in brain slices of TMT-intoxicated rats. The time-lapse recordings of AVs in EGFP-mCherry-LC3B transfected astrocytes demonstrated a reduced mobility of autophagosomes after TMT exposure respect to control cells. The observed block of the autophagic flux cannot be overcome by known autophagy inducers such as rapamycin or 0.5mM lithium. Although ineffective when used at 0.5mM, lithium at higher concentrations (2mM) was able to protect astrocyte cultures from TMT toxicity. This effect correlated well with its ability to determine the phosphorylation/inactivation of glycogen kinase synthase-3β (GSK-3β).
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Affiliation(s)
- Cinzia Fabrizi
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
| | - Elena Pompili
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
| | - Stefania De Vito
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
| | - Francesca Somma
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
| | - Angela Catizone
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
| | - Giulia Ricci
- Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - Paola Lenzi
- Department of Human Morphology and Applied Biology, Pisa, Italy.
| | - Francesco Fornai
- Department of Human Morphology and Applied Biology, Pisa, Italy; I.R.C.C.S. Neuromed, Pozzilli, Italy
| | - Lorenzo Fumagalli
- Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University, Rome, Italy
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14
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Wrzesiński T, Szelag M, Cieślikowski WA, Ida A, Giles R, Zodro E, Szumska J, Poźniak J, Kwias Z, Bluyssen HAR, Wesoly J. Expression of pre-selected TMEMs with predicted ER localization as potential classifiers of ccRCC tumors. BMC Cancer 2015; 15:518. [PMID: 26169495 PMCID: PMC5015219 DOI: 10.1186/s12885-015-1530-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 07/01/2015] [Indexed: 11/24/2022] Open
Abstract
Background VHL inactivation is the most established molecular characteristic of clear cell renal cell carcinoma (ccRCC), with only a few additional genes implicated in development of this kidney tumor. In recently published ccRCC gene expression meta-analysis study we identified a number of deregulated genes with limited information available concerning their biological role, represented by gene transcripts belonging to transmembrane proteins family (TMEMs). TMEMs are predicted to be components of cellular membranes, such as mitochondrial membranes, ER, lysosomes and Golgi apparatus. Interestingly, the function of majority of TMEMs remains unclear. Here, we analyzed expression of ten TMEM genes in the context of ccRCC progression and development, and characterized these proteins bioinformatically. Methods The expression of ten TMEMs (RTP3, SLC35G2, TMEM30B, TMEM45A, TMEM45B, TMEM61, TMEM72, TMEM116, TMEM207 and TMEM213) was measured by qPCR. T-test, Pearson correlation, univariate and multivariate logistic and Cox regression were used in statistical analysis. The topology of studied proteins was predicted with Metaserver, together with PSORTII, Pfam and Localizome tools. Results We observed significant deregulation of expression of 10 analyzed TMEMs in ccRCC tumors. Cluster analysis of expression data suggested the down-regulation of all tested TMEMs to be a descriptor of the most advanced tumors. Logistic and Cox regression potentially linked TMEM expression to clinical parameters such as: metastasis, Fuhrman grade and overall survival. Topology predictions classified majority of analyzed TMEMs as type 3 and type 1 transmembrane proteins, with predicted localization mainly in ER. Conclusions The massive down-regulation of expression of TMEM family members suggests their importance in the pathogenesis of ccRCC and the bioinformatic analysis of TMEM topology implies a significant involvement of ER proteins in ccRCC pathology. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1530-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Tomasz Wrzesiński
- Laboratory of High Throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Malgorzata Szelag
- Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Wojciech A Cieślikowski
- Department of Urology and Urological Oncology, Poznan University of Medical Sciences, Szwajcarska 3, 61-285, Poznan, Poland.
| | - Agnieszka Ida
- Department of Urology and Urological Oncology, Poznan University of Medical Sciences, Szwajcarska 3, 61-285, Poznan, Poland.
| | - Rachel Giles
- Department of Nephrology and Hypertension, University Medical Center, Postbus 85500, 3508 GA, Utrecht, Netherlands.
| | - Elżbieta Zodro
- Laboratory of High Throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Joanna Szumska
- Laboratory of High Throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Joanna Poźniak
- Laboratory of High Throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Zbigniew Kwias
- Department of Urology and Urological Oncology, Poznan University of Medical Sciences, Szwajcarska 3, 61-285, Poznan, Poland.
| | - Hans A R Bluyssen
- Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
| | - Joanna Wesoly
- Laboratory of High Throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614, Poznan, Poland.
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Yu J, Ding D, Sun H, Salvi R, Roth JA. Neurotoxicity of trimethyltin in rat cochlear organotypic cultures. Neurotox Res 2015; 28:43-54. [PMID: 25957118 DOI: 10.1007/s12640-015-9531-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/08/2015] [Accepted: 04/28/2015] [Indexed: 12/14/2022]
Abstract
Trimethyltin (TMT), which has a variety of applications in industry and agricultural, is a neurotoxin that is known to affect the auditory system as well as central nervous system of humans and experimental animals. However, the mechanisms underlying TMT-induced auditory dysfunction are poorly understood. To gain insights into the neurotoxic effect of TMT on the peripheral auditory system, we treated cochlear organotypic cultures with concentrations of TMT ranging from 5 to 100 μM for 24 h. Interestingly, TMT preferentially damaged auditory nerve fibers and spiral ganglion neurons in a dose-dependent manner, but had no noticeable effects on the sensory hair cells at the doses employed. TMT-induced damage to auditory neurons was associated with significant soma shrinkage, nuclear condensation, and activation of caspase-3, biomarkers indicative of apoptotic cell death. Our findings show that TMT is exclusively neurotoxicity in rat cochlear organotypic culture and that TMT-induced auditory neuron death occurs through a caspase-mediated apoptotic pathway.
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Affiliation(s)
- Jintao Yu
- Department of Otolaryngology Head and Neck Surgery, Xiangya Hospital, Central South University, Changsha, 410013, Hunan, China
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Abstract
The obesogen hypothesis postulates the role of environmental chemical pollutants that disrupt homeostatic controls and adaptive mechanisms to promote adipose-dependent weight gain leading to obesity and metabolic syndrome complications. One of the most direct molecular mechanisms for coupling environmental chemical exposures to perturbed physiology invokes pollutants mimicking endogenous endocrine hormones or bioactive dietary signaling metabolites that serve as nuclear receptor ligands. The organotin pollutant tributyltin can exert toxicity through multiple mechanisms but most recently has been shown to bind, activate, and mediate RXR-PPARγ transcriptional regulation central to lipid metabolism and adipocyte biology. Data in support of long-term obesogenic effects on whole body adipose tissue are also reported. Organotins represent an important model test system for evaluating the impact and epidemiological significance of chemical insults as contributing factors for obesity and human metabolic health.
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Affiliation(s)
- Felix Grün
- The Center for Complex Biological Systems, University of California Irvine, Irvine, California, USA.
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18
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Qu M, Zhou Z, Chen C, Li M, Pei L, Chu F, Yang J, Wang Y, Li L, Liu C, Zhang L, Zhang G, Yu Z, Wang D. Lycopene protects against trimethyltin-induced neurotoxicity in primary cultured rat hippocampal neurons by inhibiting the mitochondrial apoptotic pathway. Neurochem Int 2011; 59:1095-103. [PMID: 22032970 DOI: 10.1016/j.neuint.2011.10.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 10/08/2011] [Accepted: 10/12/2011] [Indexed: 01/24/2023]
Abstract
Lycopene is a potent free radicals scavenger with demonstrated protective efficacy in several experimental models of oxidative damage. Trimethyltin (TMT) is an organotin compound with neurotoxic effects on the hippocampus and other limbic structures and is used to model neurodegenerative diseases targeting these brain areas. Oxidative stress is widely accepted as a central pathogenic mechanism of TMT-mediated neurotoxicity. The present study investigated whether the plant carotene lycopene protects against TMT-induced neurotoxicity in primary cultured rat hippocampal neurons. Lycopene pretreatment improved cell viability in TMT-treated hippocampal neurons and inhibited neuronal apoptosis. Microfluorometric imaging revealed that lycopene inhibited the accumulation of mitochondria-derived reactive oxygen species (ROS) during TMT exposure. Moreover, lycopene ameliorated TMT-induced activation of the mitochondrial permeability transition pore (mPTP) and the concomitant depolarization of the mitochondrial membrane potential (ΔΨ(m)). Consequently, cytochrome c release from the mitochondria and ensuing caspase-3 activation were markedly reduced. These findings reveal that lycopene protects against TMT-induced neurotoxicity by inhibiting the mitochondrial apoptotic pathway. The anti-apoptotic effect of lycopene on hippocampal neurons highlights the therapeutic potential of plant-derived antioxidants against neurodegenerative diseases.
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Affiliation(s)
- Mingyue Qu
- Department of Occupational Health, Third Military Medical University, No. 30 Gaotanyan Street, Shapingba District, Chongqing 400038, China
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Geloso MC, Corvino V, Michetti F. Trimethyltin-induced hippocampal degeneration as a tool to investigate neurodegenerative processes. Neurochem Int 2011; 58:729-38. [DOI: 10.1016/j.neuint.2011.03.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 03/02/2011] [Accepted: 03/08/2011] [Indexed: 12/29/2022]
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20
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Bale SS, Kwon SJ, Shah DA, Kane RS, Dordick JS. A GFP complementation system for monitoring and directing nanomaterial mediated protein delivery to human cellular organelles. Biotechnol Bioeng 2010; 107:1040-7. [DOI: 10.1002/bit.22897] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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21
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Stem MR, Ellzey ML. Application of computational modeling to analyze reactive organotin(IV) species. Struct Chem 2009. [DOI: 10.1007/s11224-009-9520-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Wong HL, Liebler DC. Mitochondrial protein targets of thiol-reactive electrophiles. Chem Res Toxicol 2008; 21:796-804. [PMID: 18324786 DOI: 10.1021/tx700433m] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mitochondria serve a pivotal role in the regulation of apoptosis or programmed cell death. Recent studies have demonstrated that reactive electrophiles induce mitochondrion-dependent apoptosis. We hypothesize that covalent modification of specific mitochondrial proteins by reactive electrophiles serves as a trigger leading to the initiation of apoptosis. In this study, we identified protein targets of the model biotin-tagged electrophile probes N-iodoacetyl- N-biotinylhexylene-diamine (IAB) and 1-biotinamido-4-(4'-[maleimidoethylcyclohexane]carboxamido)butane (BMCC) in HEK293 cell mitochondrial fractions by liquid chromatography-tandem mass spectrometry (LC-MS-MS). These electrophiles reproducibly adducted a total of 1693 cysteine residues that mapped to 809 proteins. Protein modifications were selective in that only 438 cysteine sites in 1255 cysteinyl peptide adducts (35%) and 362 of the 809 identified protein targets (45%) were adducted by both electrophiles. Of these, approximately one-third were annotated to the mitochondria following protein database analysis. IAB initiated apoptotic events including cytochrome c release, caspase-3 activation, and poly(ADP-ribose)polymerase (PARP) cleavage, whereas BMCC did not. Of the identified targets of IAB and BMCC, 44 were apoptosis-related proteins, and adduction site specificity on these targets differed between the two probes. Differences in sites of modification between these two electrophiles may reveal alkylation sites whose modification triggers apoptosis.
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Affiliation(s)
- Hansen L Wong
- Department of Biochemistry, Vanderbilt University School of Medicine, U1213C Medical Research Building III, 465 21st Avenue South, Nashville, Tennessee 37232, USA
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Ehman KD, Phillips PM, McDaniel KL, Barone S, Moser VC. Evaluation of developmental neurotoxicity of organotins via drinking water in rats: Dimethyl tin. Neurotoxicol Teratol 2007; 29:622-33. [PMID: 17764894 DOI: 10.1016/j.ntt.2007.07.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Revised: 07/10/2007] [Accepted: 07/12/2007] [Indexed: 10/23/2022]
Abstract
Dimethyltin (DMT) is one of several organotins that are detected in domestic water supplies due to their use as plastic stabilizers for polyvinyl chloride (PVC) and chlorinated PVC (CPVC) products. A limited number of in vitro and in vivo studies suggest that DMT may produce developmental neurotoxicity; therefore, we initiated studies to evaluate long-term neurobehavioral changes in offspring following perinatal exposure. In the first study, female Sprague-Dawley rats were exposed via drinking water to DMT (0, 3, 15, 74 ppm) before mating and throughout gestation and lactation. Male offspring were tested for changes in: 1) preweaning learning in an associative runway task, 2) motor activity ontogeny, 3) spatial learning and retention in the Morris water maze as adults, 4) brain weight, 5) biochemical evidence of apoptosis, and 6) neuropathology. DMT toxicity was expressed as depressed maternal weight gain (74 ppm), and in the offspring, decreased brain weight (3, 74 ppm), decreased apoptosis (all concentrations), mild vacuolation in adult offspring (all concentrations), and slower learning in the water maze (15 ppm) due to altered spatial search patterns. In a second study, DMT exposure (same concentrations) occurred from gestational day 6 to weaning. Male and female offspring were tested. The high concentration again depressed maternal weight gain, decreased offspring birth weight and preweaning growth, and decreased brain weight. Increased and decreased apoptotic markers were measured, depending on age. Learning deficits were observed in the runway at postnatal day 11 (15, 74 ppm) and again in the adult offspring in the water maze (15 ppm). The results of both studies demonstrate a reproducible effect of 15 ppm perinatal DMT exposure on spatial learning. Changes in expression of apoptosis, brain weight, and the occurrence of neuropathological lesions also indicate potential neurotoxicity of DMT. These results were in contrast to earlier findings with monomethyl tin, for which only similar neuropathological lesions were observed. Thus, developmental neurotoxicity may be produced in offspring following gestational exposure to DMT in drinking water.
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Affiliation(s)
- K D Ehman
- Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
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24
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Zuccato C, Belyaev N, Conforti P, Ooi L, Tartari M, Papadimou E, MacDonald M, Fossale E, Zeitlin S, Buckley N, Cattaneo E. Widespread disruption of repressor element-1 silencing transcription factor/neuron-restrictive silencer factor occupancy at its target genes in Huntington's disease. J Neurosci 2007; 27:6972-83. [PMID: 17596446 PMCID: PMC6672230 DOI: 10.1523/jneurosci.4278-06.2007] [Citation(s) in RCA: 213] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Huntingtin is a protein that is mutated in Huntington's disease (HD), a dominant inherited neurodegenerative disorder. We previously proposed that, in addition to the gained toxic activity of the mutant protein, selective molecular dysfunctions in HD may represent the consequences of the loss of wild-type protein activity. We first reported that wild-type huntingtin positively affects the transcription of the brain-derived neurotrophic factor (BDNF) gene, a cortically derived survival factor for the striatal neurons that are mainly affected in the disease. Mutation in huntingtin decreases BDNF gene transcription. One mechanism involves the activation of repressor element 1/neuron-restrictive silencer element (RE1/NRSE) located within the BDNF promoter. We now show that increased binding of the RE1 silencing transcription factor/neuron-restrictive silencer factor (REST/NRSF) repressor occurs at multiple genomic RE1/NRSE loci in HD cells, in animal models, and in postmortem brains, resulting in a decrease of RE1/NRSE-mediated gene transcription. The same molecular phenotype is produced in cells and brain tissue depleted of endogenous huntingtin, thereby directly validating the loss-of-function hypothesis of HD. Through a ChIP (chromatin immunoprecipitation)-on-chip approach, we examined occupancy of multiple REST/NRSF target genes in the postmortem HD brain, providing the first example of the application of this technology to neurodegenerative diseases. Finally, we show that attenuation of REST/NRSF binding restores BDNF levels, suggesting that relief of REST/NRSF mediated repression can restore aberrant neuronal gene transcription in HD.
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Affiliation(s)
- Chiara Zuccato
- Department of Pharmacological Sciences and Centre for Stem Cell Research, University of Milan, Via Balzaretti 9, 20133 Milano, Italy
| | - Nikolai Belyaev
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Paola Conforti
- Department of Pharmacological Sciences and Centre for Stem Cell Research, University of Milan, Via Balzaretti 9, 20133 Milano, Italy
| | - Lezanne Ooi
- Institute of Membrane and Systems Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Marzia Tartari
- Department of Pharmacological Sciences and Centre for Stem Cell Research, University of Milan, Via Balzaretti 9, 20133 Milano, Italy
| | - Evangelia Papadimou
- Department of Pharmacological Sciences and Centre for Stem Cell Research, University of Milan, Via Balzaretti 9, 20133 Milano, Italy
| | - Marcy MacDonald
- Center for Human Genetic Research, Massachusetts General Hospital Richard B. Simches Research Center, Boston, Massachusetts 02114
| | - Elisa Fossale
- Center for Human Genetic Research, Massachusetts General Hospital Richard B. Simches Research Center, Boston, Massachusetts 02114
| | - Scott Zeitlin
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, Virginia 22908, and
| | - Noel Buckley
- Centre for the Cellular Basis of Behaviour, The James Black Centre, Institute of Psychiatry, King's College London, London SE5 9NU, United Kingdom
| | - Elena Cattaneo
- Department of Pharmacological Sciences and Centre for Stem Cell Research, University of Milan, Via Balzaretti 9, 20133 Milano, Italy
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Baken KA, Arkusz J, Pennings JLA, Vandebriel RJ, van Loveren H. In vitro immunotoxicity of bis(tri-n-butyltin)oxide (TBTO) studied by toxicogenomics. Toxicology 2007; 237:35-48. [PMID: 17553608 DOI: 10.1016/j.tox.2007.04.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Revised: 04/24/2007] [Accepted: 04/27/2007] [Indexed: 11/19/2022]
Abstract
The biocide and environmental pollutant bis(tri-n-butyltin)oxide (TBTO) causes thymus atrophy in rodents. Whether the depletion of thymic lymphocytes by tributyltin compounds may be the result of inhibition of cell proliferation or induction of apoptosis is subject of debate. We examined gene expression profiles in primary rat thymocytes exposed to TBTO in vitro at dose levels of 0, 0.1, 0.3, 0.5, and 1.0microM. By measuring cell viability and apoptosis, exposure conditions were selected that would provide information on changes in gene expression preceding or accompanying functional effects of TBTO. Several processes related to TBTO-induced toxicity were detected at the transcriptome level. Effects on lipid metabolisms appeared to be the first indication of disruption of cellular function. Many transcriptional effects of TBTO at higher dose levels were related to apoptotic processes, which corresponded to present or subsequent thymocyte apoptosis observed phenotypically. The gene expression profile was, however, not unambiguous since expression of apoptosis-related genes was both increased and decreased. Stimulation of glucocorticoid receptor signaling appeared to be a relevant underlying mechanism of action. These findings suggest that TBTO exerts its toxic effects on the thymus primarily by affecting apoptotic processes, but the possibility is discussed that this may in fact represent an early effect that precedes inhibition of cell proliferation. At the highest dose level tested, TBTO additionally repressed mitochondrial function and immune cell activation. Our in vitro toxicogenomics approach thus identified several cellular and molecular targets of TBTO that may mediate the toxicity towards thymocytes and thereby its immunosuppressive effects.
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Affiliation(s)
- Kirsten A Baken
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Health Risk Analysis and Toxicology (GRAT), Maastricht University, Maastricht, The Netherlands; National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands.
| | - Joanna Arkusz
- Nofer Institute of Occupational Medicine, Department of Toxicology and Carcinogenesis, Lodz, Poland
| | - Jeroen L A Pennings
- National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
| | - Rob J Vandebriel
- National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
| | - Henk van Loveren
- Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Health Risk Analysis and Toxicology (GRAT), Maastricht University, Maastricht, The Netherlands; National Institute of Public Health and the Environment (RIVM), Laboratory for Toxicology, Pathology and Genetics (TOX), Bilthoven, The Netherlands
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26
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Dopp E, Hartmann LM, von Recklinghausen U, Florea AM, Rabieh S, Shokouhi B, Hirner AV, Obe G, Rettenmeier AW. The cyto- and genotoxicity of organotin compounds is dependent on the cellular uptake capability. Toxicology 2007; 232:226-34. [PMID: 17316952 DOI: 10.1016/j.tox.2007.01.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 01/08/2007] [Accepted: 01/09/2007] [Indexed: 11/25/2022]
Abstract
Organotin compounds have been widely used as stabilizers and anti-fouling agents with the result that they are ubiquitously distributed in the environment. Organotins accumulate in the food chain and potential effects on human health are disquieting. It is not known as yet whether cell surface adsorption or accumulation within the cell, or indeed both is a prerequisite for the toxicity of organotin compounds. In this study, the alkylated tin derivatives monomethyltin trichloride (MMT), dimethyltin dichloride (DMT), trimethyltin chloride (TMT) and tetramethyltin (TetraMT) were investigated for cyto- and genotoxic effects in CHO-9 cells in relation to the cellular uptake. To identify genotoxic effects, induction of micronuclei (MN), chromosome aberrations (CA) and sister chromatid exchanges (SCE) were analyzed and the nuclear division index (NDI) was calculated. The cellular uptake was assessed using ICP-MS analysis. The toxicity of the tin compounds was also evaluated after forced uptake by electroporation. Our results show that uptake of the organotin compounds was generally low but dose-dependent. Only weak genotoxic effects were observed after exposure of cells to DMT and TMT. MMT and TetraMT were negative in the test systems. After forced uptake by electroporation MMT, DMT and TMT induced significant DNA damage at non-cytotoxic concentrations. The results presented here indicate a considerable toxicological potential of some organotin species but demonstrate clearly that the toxicity is modulated by the cellular uptake capability.
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Affiliation(s)
- E Dopp
- Institute of Hygiene and Occupational Medicine, University Hospital Essen, Hufelandstrasse 55, 45122 Essen, Germany.
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27
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Shintani N, Ogita K, Hashimoto H, Baba A. Recent Studies on the Trimethyltin Actions in Central Nervous Systems. YAKUGAKU ZASSHI 2007; 127:451-61. [PMID: 17329931 DOI: 10.1248/yakushi.127.451] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Trimethyltin (TMT) is a toxic organotin compound that produces injury to the central nervous systems of mammals. Recently, high-dose TMT (2.8 mg/kg) has been shown to produce neurodegeneration and subsequent neurogenesis specifically in the hippocampal dentate gyrus of mice, indicating that mice injected with TMT serve as a useful in vivo model to study neurogenesis as well as neurodegeneration in this brain region. In addition, gene-engineered mice have allowed research to focuse on the mechanisms of TMT toxicity. These studies have revealed the involvement of stannin, nuclear factor kappa B (NF-kappaB), presenilin-1, apolipoprotein E, and pituitary adenylyl cyclase-activating polypeptide (PACAP) in TMT toxicity and suggested the relationship between genetic mutations and neuronal susceptibility to degeneration. In this review, we briefly summarize the previous studies and discuss the current status of research on TMT.
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Affiliation(s)
- Norihito Shintani
- Laboratory of Molecular Neuropharmacology, Graduate School of Pharmaceutical Sciences, Osaka University, Suita City, Japan.
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28
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Billingsley ML, Yun J, Reese BE, Davidson CE, Buck-Koehntop BA, Veglia G. Functional and structural properties of stannin: roles in cellular growth, selective toxicity, and mitochondrial responses to injury. J Cell Biochem 2006; 98:243-50. [PMID: 16453279 DOI: 10.1002/jcb.20809] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Stannin (Snn) was discovered using subtractive hybridization methodology designed to find gene products related to selective organotin toxicity and apoptosis. The cDNAs for Snn were first isolated from brain tissues sensitive to trimethyltin, and were subsequently used to localize, characterize, and identify genomic DNA, and other gene products of Snn. Snn is a highly conserved, 88 amino acid protein found primarily in vertebrates. There is a minor divergence in the C-terminal sequence between amphibians and primates, but a nearly complete conservation of the first 60 residues in all vertebrates sequenced to date. Snn is a membrane-bound protein and is localized, in part, to the mitochondria and other vesicular organelles, suggesting that both localization and conservation are significant for the overall function of the protein. The structure of Snn in a micellar environment and its architecture in lipid bilayers have been determined using a combination of solution and solid-state NMR, respectively. Snn structure comprised a single transmembrane domain (residues 10-33), a 28-residue linker region from residues 34-60 that contains a conserved CXC metal binding motif and a putative 14-3-3xi binding region, and a cytoplasmic helix (residues 61-79), which is partially embedded into the membrane. Of primary interest is understanding how this highly-conserved peptide with an interesting structure and cellular localization transmits both normal and potentially toxic signals within the cell. Evidence to date suggests that organotins such as trimethyltin interact with the CXC region of Snn, which is vicinal to the putative 14-3-3 binding site. In vitro transfection analyses and microarray experiments have inferred a possible role of Snn in several key signaling systems, including activation of the p38-ERK cascade, p53-dependent pathways, and 14-3-3xi protein-mediated processes. TNFalpha can induce Snn mRNA expression in endothelial cells in a PKC-epsilon dependent manner. Studies with Snn siRNA suggest that this protein may be involved in growth regulation, since inhibition of Snn expression alone leads to reduced endothelial cells growth and induction of COP-1, a negative regulator of p53 function. A key piece of the puzzle, however, is how and why such a highly-conserved protein, localized to mitochondria, interacts with other regulatory proteins to alter growth and apoptosis. By knowing the structure, location, and possible signaling pathways involved, we propose that Snn constitutes an important sensor of mitochondrial damage, and plays a key role in the mediation of cross-talk between mitochondrial and nuclear compartments in specific cell types.
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Affiliation(s)
- M L Billingsley
- Department of Pharmacology, College of Medicine, Pennsylvania State University, Hershey, 17033, USA.
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29
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Buck-Koehntop BA, Mascioni A, Buffy JJ, Veglia G. Structure, dynamics, and membrane topology of stannin: a mediator of neuronal cell apoptosis induced by trimethyltin chloride. J Mol Biol 2005; 354:652-65. [PMID: 16246365 DOI: 10.1016/j.jmb.2005.09.038] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2005] [Revised: 09/12/2005] [Accepted: 09/13/2005] [Indexed: 10/25/2022]
Abstract
Organotin compounds or alkyltins are ubiquitous environmental toxins that have been implicated in cellular death. Unlike other xenobiotic compounds, such as organomercurials and organoleads, alkyltins activate apoptotic cascades at low concentrations. Trimethyltin (TMT) chloride is amongst the most toxic organotin compounds, and is known to selectively inflict injury to specific regions of the brain. Stannin (SNN), an 88-residue mitochondrial membrane protein, has been identified as the specific marker for neuronal cell apoptosis induced by TMT intoxication. This high specificity of TMT makes SNN an ideal model system for understanding the mechanism of organotin neurotoxicity at a molecular level. Here, we report the three-dimensional structure and dynamics of SNN in detergent micelles, and its topological orientation in lipid bilayers as determined by solution and solid-state NMR spectroscopy. We found that SNN is a monotopic membrane protein composed of three domains: a single transmembrane helix (residues 10-33) that transverses the lipid bilayer at approximately a 20 degrees angle with respect to the membrane normal; a 28 residue unstructured linker, which includes a conserved CXC metal-binding motif and a putative 14-3-3zeta binding domain; and a distorted cytoplasmic helix (residues 61-79) that is partially absorbed into the plane of the lipid bilayer with a tilt angle of approximately 80 degrees from the membrane normal. The structure and architecture of SNN within the lipid environment provides insight about how this protein transmits toxic insults caused by TMT across the membrane.
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Affiliation(s)
- Bethany A Buck-Koehntop
- Department of Chemistry, University of Minnesota, 207 Pleasant St. SE, Minneapolis, MN 55455-0431, USA
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30
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Davidson CE, Reese BE, Billingsley ML, Yun JK. The protein stannin binds 14-3-3ζ and modulates mitogen-activated protein kinase signaling. ACTA ACUST UNITED AC 2005; 138:256-63. [PMID: 15923056 DOI: 10.1016/j.molbrainres.2005.04.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2004] [Revised: 04/05/2005] [Accepted: 04/18/2005] [Indexed: 11/29/2022]
Abstract
The molecular mechanisms underlying the selective toxicity of trimethyltin (TMT) remain unclear. Stannin (Snn), a protein preferentially expressed in TMT-sensitive cells, provides a direct link to the molecular basis for TMT toxicity. Recent evidence demonstrated that Snn peptides bind and de-alkylate TMT to dimethyltin (DMT); Snn may mediate both TMT and DMT toxicity. In this study, we demonstrate that Snn co-immunoprecipitates with a scaffolding protein 14-3-3, specifically with 14-3-3zeta isotype. Consistent with this, a detailed amino acid sequence analysis shows that Snn contains a putative 14-3-3 protein-binding site located within its hydrophilic loop. In addition, we present the evidence that Snn overexpression results in reduced extracellular regulated kinase activation and increased p38 activation. In contrast, the activity of c-Jun N-terminal kinase did not change following Snn overexpression. This is the first evidence that demonstrates a direct interaction between Snn and MAPK signaling molecules. Together, these findings indicate a role of Snn in modulation of MAPK signaling pathways through its interactions with 14-3-3zeta.
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Affiliation(s)
- Collin E Davidson
- Department of Pharmacology, Pennsylvania State University, Milton S. Hershey College of Medicine, Hershey, PA 17033, USA
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31
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Reese BE, Davidson C, Billingsley ML, Yun J. Protein kinase C epsilon regulates tumor necrosis factor-alpha-induced stannin gene expression. J Pharmacol Exp Ther 2005; 314:61-9. [PMID: 15798003 DOI: 10.1124/jpet.105.084236] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Stannin (Snn) is a highly conserved vertebrate protein that has been closely linked to trimethyltin (TMT) toxicity. We have previously demonstrated that Snn is required for TMT-induced cell death. Others have shown that TMT exposure results in tumor necrosis factor-alpha (TNFalpha) production and that TNFalpha treatment induces Snn gene expression in human umbilical vein endothelial cells (HUVECs). In this study, we investigated a signaling mechanism by which Snn gene expression is regulated by TMT and demonstrated that TNFalpha stimulates Snn gene expression in a protein kinase C epsilon-dependent manner in HUVECs in response to TMT exposure. Supporting this, we show that TMT-induced toxicity is significantly blocked by pretreatment with an anti-TNFalpha antibody in HUVECs. Using a quantitative real-time polymerase chain reaction assay, we also show that the level of Snn gene expression is significantly increased in HUVECs in response to either TMT or TNFalpha treatment. This TNFalpha-induced Snn gene expression is blocked when HUVECs were pretreated with bisindolylmaleimide I, an inhibitor of protein kinase C (PKC). In contrast, when HUVECs were treated with phorbol 12-myristate 13-acetate, a PKC activator, we observed a significant increase in Snn gene expression. Using isotype-specific siRNA against PKC, we further show that knockdown of PKC epsilon, but not PKC delta or PKC zeta, significantly blocked TNFalpha-induced Snn gene expression. Together, these results indicate that TNFalpha-induced, PKC epsilon-dependent Snn expression may be a critical factor in TMT-induced cytotoxicity.
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Affiliation(s)
- Brian E Reese
- Department of Pharmacology , Penn State College of Medicine, Hershey, PA 17033, USA
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